Dissertations / Theses on the topic 'Gear Machines'
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1
Grebchenko, A. "Mechanization and automation gear milling." Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/33627.
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Cutting teeth is the most time consuming process in the technology of gears. It spent 50 - 60% of the total labor input processing gear. Therefore, improving the efficiency of the process is an important task gear milling machine.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33627
2
Gulati, Sidhant, Andrea Vacca, and Manuel Rigosi. "A General Method to Determine the Optimal Profile of Porting Grooves in Positive Displacement Machines: the Case of External Gear Machines." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199832.
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In all common hydrostatic pumps, compressibility affects the commutation phases of the displacing chambers, as they switch their connection from/to the inlet to/from the outlet port, leading to pressure peaks, localized cavitation, additional port flow fluctuations and volumetric efficiency reduction. In common pumps, these effects are reduced by proper grooves that realizes gradual port area variation in proximity of these transition regions. This paper presents a method to automatically find the optimal designs of these grooves, taking as reference the case of external gear pumps. The proposed procedure does not assume a specific geometric morphology for the grooves, and it determines the best feasible designs through a multi-objective optimization procedure. A commercial gear pump is used to experimentally demonstrate the potentials of the proposed method, for a particular case aimed at reducing delivery flow oscillations.
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Gullo, Thomas W. "A Methodology to Evaluate the Dynamic Behavior of Back-to-back Test Machines." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555588592218025.
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Wichert, Torsten. "Design and Construction Modifications of Switched Reluctance Machines." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1235569858100-62518.
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Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.
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Wichert, Torsten. "Design and Construction Modifications of Switched Reluctance Machines." Doctoral thesis, Technische Universität Warschau, 2008. https://slub.qucosa.de/id/qucosa%3A258.
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Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.
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Kraicinger, Lukáš. "Software pro zpracování dat a řízení CNC obráběcího stroje." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363853.
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The thesis focuses on the design and impelementation of a control system for a CNC machine producing gears with specific integrated CAM system. The study includes practical verification of system functionality, which includes the design and creation of an electronic circuit on this machine. A prototype of a 6-axis machine is being developed at the Faculty of Mechanical Engineering BUT in Brno as a master thesis simultaneously with the creation of this term project. It is a compact automated gear producing machine (all in one) which requires only appropriate semifinished product and correctly set parameters of teeth using the touch screen on the machine.
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Клочко, А. А., and Ю. А. Синица. "Улучшение рабочих характеристик среднемодульных зубчатых передач, полученных на зубофрезерном станке с числовым программным управлением." Thesis, Сумский государственный университет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/61466.
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В настоящее время актуальной является задача снижения уровня
шумов зубчатых передач в связи с ужесточением и нормированием
требований к уровню шумов автотракторной техники. По традиционной
технологии до последнего времени практически все зубчатые колеса
грузовых автомобилей, тракторов и сельхозмашин в странах СНГ
изготавливались без зубошлифования. Требуемая точность зубчатых колес
устанавливалась отраслевыми стандартами, которые, позволяли
изготавливать зубчатые колеса на отечественном оборудовании используя
инструмент отечественного производства.В настоящее время актуальной является задача снижения уровня шумов зубчатых передач в связи с ужесточением и нормированием требований к уровню шумов автотракторной техники. По традиционной технологии до последнего времени практически все зубчатые колеса грузовых автомобилей, тракторов и сельхозмашин в странах СНГ изготавливались без зубошлифования. Требуемая точность зубчатых колес устанавливалась отраслевыми стандартами, которые, позволяли изготавливать зубчатые колеса на отечественном оборудовании используя инструмент отечественного производства.
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Jermolajev, Štěpán. "Kontinuální odvalovací broušení čelního ozubení." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230504.
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The diploma thesis deals with the technology of continuous generating gear grinding. With reference to this technology, used grinding wheels and grinding machines are described. A detailed analysis is devoted to the technological parameters of the grinding process and their influence on the resultant tooth flank surface integrity. In order to verify described rules, the diploma thesis contains results of practical experiments as well.
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Hajar, Mayssaa. "Contribution of random sampling in the context of rotating machinery diagnostic." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSES001/document.
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Récemment, le diagnostic des machines tournantes devient un des sujets de recherche les plus importants. Plusieurs axes sont développés dans ce domaine : traitement de signal, reconnaissance des formes et autres. En plus, les systèmes industriels peuvent être surveillés à distance en temps réel grâce à la disponibilité de l’internet. Cette surveillance se trouve exigeante au niveau de l’acquisition et le stockage des données. En 2004, le Compressive Sensing est introduit dans le but d’acquérir les données a une basse fréquence afin d’économiser l’énergie dans les réseaux de capteurs sans fils. Des résultats similaires peuvent être achevés par l’Echantillonnage Aléatoire qui procure une acquisition à basse fréquence grâce à sa propriété d’anti-repliement. Comme cette technique d’échantillonnage est jusqu’à l’instant de la rédaction de cette thèse n’est pas encore disponible au marché, le travail sur ce sujet se trouve promettant afin de présenter une implémentation pratique validée. D’où, la contribution de cette thèse est de présenter les différentes propriétés de l’échantillonnage aléatoire à travers une étude théorique détaillée dans le domaine temporel et fréquentiel suivie d’une simulation et d’une application pratique sur des signaux synthétisés simples puis sur des signaux de vibration extraits des principaux composants des machines : roulements et engrenages. Les résultats obtenus au niveau de la simulation et la pratique sont satisfaisants grâce à la diminution de la fréquence d’échantillonnage et la quantité de données à sauvegarder ce qui peut être considéré comme une résolution de la problématique de la surveillance à temps réelNowadays, machine monitoring and supervision became one of the most important domains of research. Many axes of exploration are involved in this domain: signal processing, machine learning and several others. Besides, industrial systems can now be remotely monitored because of the internet availability. In fact, as many other systems, machines can now be connected to any network by a specified address due to the Internet of Things (IOT) concept. However, this combination is challenging in data acquisition and storage. In 2004, the compressive sensing was introduced to provide data with low rate in order to save energy consumption within wireless sensor networks. This aspect can also be achieved using random sampling (RS). This approach is found to be advantageous in acquiring data randomly with low frequency (much lower than Nyquist rate) while guaranteeing an aliasing-free spectrum. However, this method of sampling is still not available by hardware means in markets. Thus, a comprehensive review on its concept, its impact on sampled signal and its implementation in hardware is conducted. In this thesis, a study of RS and its different modes is presented with their conditions and limitations in time domain. A detailed examination of the RS’s spectral analysis is then explained. From there, the RS features are concluded. Also, recommendations regarding the choice of the adequate mode with the convenient parameters are proposed. In addition, some spectral analysis techniques are proposed for RS signals in order to provide an enhanced spectral representation. In order to validate the properties of such sampling, simulations and practical studies are shown. The research is then concluded with an application on vibration signals acquired from bearing and gear. The obtained results are satisfying, which proves that RS is quite promising and can be taken as a solution for reducing sampling frequencies and decreasing the amount of stored data. As a conclusion, the RS is an advantageous sampling process due to its anti-aliasing property. Further studies can be done in the scope of reducing its added noise that was proven to be cyclostationary of order 1 or 2 according to the chosen parameters
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Stenekap, Daniel. "Classification of Gear-shift data using machine learning." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-53445.
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Today, automatic transmissions are the industrial standard in heavy-duty vehicles. However, tolerances and component wear can cause factory calibrated gearshifts to have deviations that have a negative impact on clutch durability and driver comfort. An adaptive shift process could solve this problem by recognizing when pre-calibrated values are out-dated. The purpose of this thesis is to examine the classification of shift types using machine learning for the future goal of an adaptive gearshift process. Recent papers concerning machine learning on time-series are reviewed. Adata set is collected and validated using hand-engineered features and unsupervised learning. Four deep neural networks (DNN) models are trained on raw and normalized shift data. Three of the models show good generalization and perform with accuracies above 90%. An adaption of the fully convolutional network (FCN) used in [1] shows promise due to relative size and ability to learn the raw data sets. An adaptation of the multi-variate long short time memory fully convolutional network (MLSTMFCN) used in [2] is superior on normalized data sets. This thesis shows that DNN structures can be used to distinguish between time-series of shift data. However, much effort remains since a database for shift types is necessary for this work to continue.
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Li, Xianren. "Optimised parametric gear system design." Thesis, Sheffield Hallam University, 1994. http://shura.shu.ac.uk/19957/.
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This thesis is the summary of the research work that has been carried out by the author on the development of methods of optimum gear design and shaft design for gear boxes, and the integration of the methods into one software package together with parametric layout drawing. The objective of the optimum gear design is to minimise the gear centre distance with a fixed aspect ratio of pinion, when power capacity requirement is given. Although power capacity is dependant upon many factors, the optimum gear design method has used module, numbers of teeth, and helix angle as the significant variables. The power capacity rating is calculated by AGMA standards and the optimum design method is based on a study of the numerical behaviour of the AGMA power capacity rating and transformation of the gear design constraints into direct limiting boundaries on design variables. Numerical example tests show that the method is efficient and effective in finding the global minimum centre distance design. The shaft component design method is based on established theories for reaction calculation, bearing life rating, shaft stress calculation and shaft failure criterion. However, the layout of the gear box is defined by a unique system using vectors connecting shaft and gear centres. The gear design and shaft design methods are implemented in an integrated software package and a well defined data organisation provides the basis for data sharing. The definition of layout by centre vectors also serves as the reference frame around which to draw the layout by parametric programs. The design results of the software package are obtained by parametric programs from a data file based on the same data organisation. Parametric programs for individual shaft, bearing, and gears are written to draw the components and main dimensions such as centre distances, component axial positions, gear sizes and bearing sizes are shown on the layout. The contribution to knowledge by this investigation is mainly in the gear design area, viz., the study of the numerical behaviour of AGMA standards in relation to gear geometry and the development of the efficient and effective algorithm for the optimum gear design. The descriptive layout definition by centre vectors is also a novel feature.
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Wang, Hong. "MACHINE HEALTH MONITORING OF ROTOR-BEARING-GEAR TRANSMISSION SYSTEM." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133281063.
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Eggers, Berndt Leonard. "Draglines gear monitoring under fluctuating conditions /." Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-08272008-134253/.
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Zhang, Yaojun. "Mathematical bases for gear inspection by 3D coordinate measuring machine." Doctoral thesis, Universite Libre de Bruxelles, 1995. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212619.
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Echeverria-Villagomez, Jose Salvador. "The use of tangential accelerometers in gear drives." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334077.
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Ligata, Haris. "Impact of system-level factors on planetary gear set behavior." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1172599656.
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Fish, Michael Anderson. "Transmission errors in precision worm gear drives." Thesis, University of Huddersfield, 1998. http://eprints.hud.ac.uk/id/eprint/4851/.
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Transmission error is a measure of the positioning accuracy of a gear system. This has been widely documented in gearing for many years as the source of problems in noise and vibration. It is a result of errors in the contact conditions which affect the driven gear with respect to the rotation of the driver gear. This research aims to present a better understanding of the basic kinematics of worm gear systems by identifying the significant influences which determine the contact conditions. A literature review of existing theory is described which determines the major areas considered in worm gear contact analysis. Formulae are derived which quantify the effect of component parameter variation on contact. An investigation of the design, manufacture, and operating processes is recorded which identifies error sources relative to the theoretical contact condition. A computer program is developed which calculates contact characteristics such as worm and wheel component form, transmission error and contact marking pattern for a given design including any contact error sources. Computer calculations are validated by comparing direct measurements of these characteristics from several manufactured gear sets with synthesised results produced using the design information, machine settings and error sources detected during production. The behaviour of these gear sets during operation under a torque load has been investigated experimentally. Measured transmission error data from a test rig is used to develop a basic model of worm gear deformation under load. This model has been added to the computer program to improve and extend the analysis capability. The test rig has also been used to investigate the effect of initial wear on contact characteristics. The good correlation between calculated and experimental results shows that the characteristics of a worm gear set can be predicted once all elements of the design and manufacture are known. The results also validate the software as a useful design tool for academic and industrial applications. Important conclusions are drawn on design techniques, the manufacturing process, and the effects of operating under load. Further areas of investigation are identified which offer future research an opportunity to expand upon these conclusions.
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Alshahrany, Shaya. "Rolling contact fatigue in heavily loaded gear transmission contacts." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/90422/.
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This thesis examines the influence of asperities such as found on the teeth of gears and discs, and failure mechanisms associated with rough surface Elastohydrodynamic Lubrication (EHL). The principal outcomes of the research provide a good insight into fatigue life, residual stress effects, damage prediction and surface contact failures. In particular, the study is intended to provide understanding into the residual stress distribution resulting from plastic deformation of surface asperities in the running in process. The residual stress is then added to the asperity elastic stress distribution and examined in detail to see the effects on fatigue damage and fatigue life. So, a theoretical model has been developed to assist design against the residual stress effect and surface contact fatigue, such as micropitting. The technique used in the study starts with developing an elastic plastic model of the rough surface by using the Abaqus Finite Element analysis software package. This is a nonlinear problem and ranges of applied loads have been applied to the as-manufactured surfaces causing the asperity features to experience varying degrees of plastic deformation. The pre and post running roughness profiles are studied in order to assess the level of plastic deformation actually occurring at significant surface asperity features by aligning the pre and post running profiles. This results in a new technique that has helped to identify the level of plastic deformation occurring in the practice, and also to make a comparison with FEA contact analysis for the same asperity features to identify the appropriate residual stress field. The residual stress field associated with the plastic deformation was extracted and evaluated. The extracted residual stress field was transferred to a form that facilitated IV inclusion in stress evaluation code to obtain the stress history for the material subject to loading in an EHL contact. The research carried out considers surface fatigue analysis with and without a residual stress field, so as to establish the influence of asperity plastic deformation on the fatigue properties of the surface. All the work is based on numerical simulation of surface fatigue failure in EHL situations and carried out numerically. The procedure can be applied quickly and gives the opportunity to apply several models and investigate the influence of all the model parameters on material deformation and fatigue life.
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Frith, Robert Hedley. "A model of gear pump wear due to solids contamination." Thesis, Queensland University of Technology, 1994.
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Hoseini, Saba. "Experimental simulation of gear hobbing through a face milling concept in CNC-machine." Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-126804.
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Johnson, David Ewen. "Use of noise for the detection of gear faults in rotating machinery." Thesis, University of the West of England, Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358312.
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Lerch, Christopher Allen. "Non-invasive recovery of gear rotation from machine vibration dc by Christopher Allen Lerch." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/35019.
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Chen, Dajun. "Applications of time-scale representations and artificial neural networks in gear condition monitoring." Thesis, De Montfort University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391569.
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Wolfer, Scott. "Design and Analysis of A General-Purpose Planetary Gear Durability Test Machie." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1409148817.
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Li, Zheng. "Spur gear teeth contact analysis on power-train transmission noise, vibration and harshness." Thesis, University of Warwick, 2009. http://wrap.warwick.ac.uk/3163/.
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The gear meshing is very complex process as high non-linearity behaviour is involved during the process. Normally most analysis of gear tooth contact is on the basis of a hypothesis that the contacted gear teeth are cantilever beams to obtain the approximate results quickly. However, many important factors have been ignored in simulating gear tooth contact using cantilever beam hypothesis, those factors include tooth profile variations, gear rotation speed and input torque, coefficient of friction and geometry distortion. Many of non-linear responses such as noise, vibration, abrasion and so on make the actual contact process much more complicated than those in the cantilever beam hypothesis although it is a reliable reference for integrated gear performance investigation. The main contribution of this thesis is in the investigation of the typical static and dynamic performances of meshing gears by simulating gears rolling-sliding contact processes using non-linear finite element method. A typical spur gear model has been proposed first for performance analysis and the model with integrated parameters could contribute reliable finite element conditions to simulate actual gear meshing. The bending stress and its resultant stress of contacted teeth with static model and dynamic model have been then simulated and the results can be used to provide information on the contacted teeth stresses distribution. The detailed investigation of transmission error in gear meshing has been carried out to understand harmful noise and vibration of gear set and a micro geometry modification of gear tooth profile has been proposed, i.e. tip relief. The gear contact pressure distributions and transmission errors have been then analyzed with micro geometry modification and the analysis is under static and dynamic boundary conditions. Finally, the most significant contribution of the thesis is the investigation of the frictional effect on dynamic performance, including dynamic stress and transmission errors.
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Österlind, Tomas. "An Analysis of Machining System Capability and Its Link with Machined Component Quality." Licentiate thesis, KTH, Maskin- och processteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122144.
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Machining components out of tolerances is of no use in competitiveproduction. The machining system sets the limitations of dimensionalaccuracy and surface quality of a machined component. The capabilityof the machining system describes these limits in terms of specifiedvalues. This thesis deals with machining system capability analysismainly focused on machine tool static and dynamic stiffness.The influence of stiffness and flexibility on machining systemcapability is analytically and experimentally investigated. Theexperimental work presented in the thesis complies with the theoriesand shows the relation between machine tool capability and theoutcome on the machine component.The concept of capability analysis by elastic linked system andthe currently available tools for such an evaluation is presented anddiscussed. The basis of elastic linked system analysis is the use ofmeasurements under loaded condition. The machine tool is loadedwith a known force creating a test condition closer to real machining,compared to current methods of unloaded machine tools. Twomeasurement tools for elastic linked system capability analysis areexplained in the thesis: Loaded Double Ball Bar and ContactlessExcitation and Response System.The thesis consists of an analytical base and an experimental casestudy on spiral bevel gear face milling. The experiments are discussedand compiled with the given theories.QC 20130513
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Krumins, Armands. "Gearbox fault detection, based on Machine Learning of multiple sensors." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-301603.
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The increasing demand for higher efficiency and lower environmental impact of transmissions, used in automotive and wind energy industries has created a need for more advanced technical solutions to fulfil those requirements. Condition monitoring plays an important role in the transmission life cycle, saving resources and time. Recently condition monitoring, using machine learning has shifted from reactive to proactive action, predicting minor faults before they become significant. This thesis intends to develop a methodology that can be used to predict faults like pitting initiation, before propagating in FZG test rig, available at KTH Machine Design department. Standard sensor measurements already available like temperature, rotation speed and torque are used in this project. Four kinds of gears were used, two made of wrought, and two – of powder metal steel, each with ground or superfinish surface. After a literature review about pitting fatigue, condition indicators for these failures and machine learning were done, a statistical analysis was done, to see how the transmission behaves during testing and to have comparison material, helpful when having machine learning results. Two machine learning models, Decision Tree and Support Vector Machine were selected and trained in two combinations, either with Root Mean Square only, or with Crest Factor, Standard Deviation and Kurtosis in addition. As a result, 64 models were trained, 32 for all tests and another 32 to investigate two particular tests due to a longer pitting propagation period. New condition indicators like Standard Deviation and Signal – to – noise ratio was calculated to get more nuanced trends than just using one measurement to monitor the gearbox behavior. After comparing with the results from statistical analysis and previously done tooth profile measurements, it was concluded that the new indicators could indicate the change in gearbox operation before the first pitting initiation is detected, using tooth profile measurement.
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Liu, Huaiju. "Lubricated contact analysis of a spur gear pair with dynamic loads." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/57917/.
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In the present research study, a comprehensive spur gear lubrication analysis has been carried out to understand the gear contact behaviour under lubrication conditions. The modelling works have been extended to consider the effects of thermal mechanical, non-Newtonian fluid, surface roughness, transient squeeze and dynamic load conditions. First, the elastohydrodynamic lubrication theory is studied and relevant numerical approaches are introduced. The reduced Reynolds equation technique is applied to deal with any potential "asperity contacts" or any other ultra-thin film situations. Those situations could be a result of the surface roughness or the dynamic load effect. This approach allows us to capture local information about pressure, traction, film thickness, etc., within the nominal contact zone. Influence of working conditions, i.e. load, rolling speed, as well as the sliding to roll ratio are discussed with those models (Newtonian or non-Newtonian fluids, isothermal or thermal conditions). The non-Newtonian fluid effect has been investigated with a Ree-Eyring fluid model and a power-law fluid model and the thermal effect is studied by solving energy equations of interacting solids and the film numerically with the sequential sweeping technique. The dynamic effect on contact performance is also studied. The dynamic load is calculated using a two degree-of-freedom lumped parameter system dynamic model in which the varying mesh stiffness is considered as the excitation. The dynamic model is solved using the Runge-Kutta method. The effects of the dynamic load effect on pressure distribution and film thickness in a whole mesh period are discussed. The normal contact stiffness of a spur gear pair is also predicted based on the deterministic tribology models. The main contributions from the present research could be summarized as follows: i. An elastohydrodynamic lubrication model for a spur gear pair is developed by taking into account the effects of transient squeeze, the non-Newtonian fluid, the rough surface and the thermal mechanical contacts which makes the proposed model one of the most advanced models currently evaluating gear lubrication performance. This model can also be applied to bearings, cams, or other gear types with some modifications. ii. The friction behaviour, which is not investigated as extensively as the film thickness in existing work, is studied. The effects of the working conditions (the load, the rolling speed, the slide/roll ratio), the non-Newtonian conditions, the rough surface conditions, as well as the thermal conditions on friction behaviour are discussed. The conclusions suggest controlling surface topography patterns and working conditions aiming at a reduced friction coefficient and a longer service life. iii. The dynamic effect on lubrication performance and effect of lubrication on normal contact stiffness of a spur gear pair are studied. The work provides a potential gateway for a more comprehensive evaluation of spur gear pair working performance using a tribology-dynamic coupled method which is the next area this author would like to explore.
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Ali, Emad, Jürgen Weber, and Matthias Wahler. "A Machine Learning Approach for Tracking the Torque Losses in Internal Gear Pump - AC Motor Units." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199438.
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This paper deals with the application of speed variable pumps in industrial hydraulic systems. The benefit of the natural feedback of the load torque is investigated for the issue of condition monitoring as the development of losses can be taken as evidence of faults. A new approach is proposed to improve the fault detection capabilities by tracking the changes via machine learning techniques. The presented algorithm is an art of adaptive modeling of the torque balance over a range of steady operation in fault free behavior. The aim thereby is to form a numeric reference with acceptable accuracy of the unit used in particular, taking into consideration the manufacturing tolerances and other operation conditions differences. The learned model gives baseline for identification of major possible abnormalities and offers a fundament for fault isolation by continuously estimating and analyzing the deviations.
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Zorgani, Muftah Em M. "Procedure for selecting appropriate steels for machine design." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6837.
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Selection of steels for industrial purposes usually means choosing a type of steel to make a part or a product. The steel that is chosen must meet all the designer requirements. A quantitative selection procedure has been used to analyze the large amount of data involved in this selection process so that a complete and systematic evaluation can be made.
The designer is responsible for the selection of steel, and this selection requires the designer to find data and information on the mechanical properties required, and also learns ways to improve these properties through different heat treatment processes.
When a large number of steels and a large number of specified mechanical properties are being evaluated for selection, the weighed properties method can require a large number of tedious and time-consuming calculations. In such cases a computer program could greatly facilitate the selection process.
This thesis reports the selection of steels for gears, shafts, fasteners and springs where the steps involved in the weighted properties method which is written in the form of a simple computer program to select steels from a data bank. This program also includes the digital logic method to help in determining weighing factors.
The steels are ranked according to standard designation; BS, AISI, and DIN. It has been found that alloyed steels hardened and tempered at 2050C are most suitable for gears, shafts, fasteners, and springs when higher mechanical properties required, and carbon and low alloyed steels when cost is the main consideration.
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Cavina, Eugenio. "GEAR: una piattaforma Big Data per l'elaborazione di stream di dati attraverso Machine Learning e Business Rules." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20416/.
Full textAbstract:
Nel panorama digitale degli ultimi anni, l’utilizzo dei pagamenti elettronici è in continua crescita. La conseguente delibera di regolamentazioni per la tutela dei consumatori implica anche l’utilizzo di sistemi di Online Fraud Detection (OFD) in grado di gestire grandi quantità di dati. La tesi parte dai sistemi OFD (tipicamente proprietari) per creare una soluzione più generale rispetto al dominio specifico e con tecnologie open source. I sistemi di OFD presentano infatti caratteristiche generalizzabili e riutilizzabili in domini applicativi diversi dai pagamenti elettronici e queste sono state estratte per creare una soluzione più generale. Questo sistema è basato su alcuni passaggi astratti e concettuali, da eseguire in real-time su uno stream di dati. Si definisce quindi il modello GEAR (Gather, Enrich, Assess, React), l’architettura della pipeline di trasformazione dei dati e infine uno stack tecnologico di strumenti Big Data. Si illustra anche una possibile implementazione dei componenti della pipeline, disaccoppiati e riutilizzabili, con allegate valutazioni delle prestazioni su un caso d’uso. La piattaforma creata implementa il modello attraverso l’utilizzo trasparente, da parte dei componenti, di algoritmi di machine learning e regole di business (attraverso un Business Rules Management System distribuito), abilitando di fatto il loro utilizzo per l’elaborazione di stream di dati.
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Masat, Mehmet. "Design And Implementation Of Hot Precision Forging Die For A Spur Gear." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608550/index.pdf.
Full textAbstract:
There is a strong need in forging industry to reduce waste of material, improve quality, and reduce cost of forgings. About 30% of the material is wasted during conventional closed-die forging. Therefore, in order to reduce the cost of forged products and to obtain near-net or net shape parts, new forging methods should be applied. Precision forging concept is a cost-effective way to produce net-shape or near-net shape components. In recent years, there has been an increased interest in the production of gears by the net-shape forging technique. This has specific advantages over the traditional manufacturing processes of cutting gears such as hobbing, turning, and grinding including savings on cost and raw material, increased productivity, and gears with higher
dynamic properties than conventionally cut ones.
In this study, precision forging of a particular spur gear has been investigated. The precision forging die set has been conceptually designed and
modeled in a computer aided design environment. The forging process of particular spur gear has been simulated by using a commercially available finite volume program. After the successful simulation results, the prototype die set
and the tube-shaped billets were manufactured. The real-life experiments have been realized by using 1000 tons mechanical forging press available in METUBILTIR
Research and Application Center Forging Laboratory. The results have been compared with the computer simulations. After the real-life experiments, it has been observed that the conceptual die design is appropriate and near-net
shape spur gears are successfully obtained by the proposed precision forging die set.
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Hoskins, Thomas James. "The mechanical and tribological properties of PEEK gears." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6047/.
Full textAbstract:
This research compares the dynamic performance of injection moulded and laser sintered poly-ether-ether-ketone (PEEK), outlining the potential of laser sintering as a manufacturing method for high performance polymer gears. It was observed that the mechanical properties of laser sintered PEEK was a significant improvement over previous laser-sintered materials, and comparable with high performance injection-moulded materials. In addition, the coefficient of friction and wear rates were significantly below that of injection moulded PEEK. However, for direct application of the laser sintered material EOS PEEK HP3 to power transmission gears, the predominant form of failure was bending fatigue, limiting the material to low power transmission levels. Observation of the fracture surface highlighted limited amounts of plasticity, although regions of intergranular failure and fast fracture could be identified from the failed surface. In addition, the failure stress path, in the region of progressive intergranuar failure, was governed by the partially sintered particle boundaries in the material; showing a similar failure response to flexure testing. In conclusion, despite the limited amount of plasticity shown in the material failure, the tribological properties of laser sintered PEEK mean that their application to power transmission is still desirable.
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Westerberg, Johan. "Utveckling och utvärdering av en rörrensningsmaskin." Thesis, KTH, Maskinkonstruktion (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-183517.
Full textAbstract:
I den här rapporten presenteras en konstruktion av en ny rörrensningsmaskin som beställts av ett företag verkande inom rörrensningsbranschen. Konstruktionen som togs fram har; en grund i plast, vilken kan formgjutas i ett stycke, en modul med alla komponenter samlade inne i rörrensningsmaskinens trumma, teleskophandtag som gör den lätt att förvara, samt förvaringsmöjligheter för extra tillbehör. Prestandan på maskinen har optimerats genom mätserier och beräkningar, vilket gett en optimal effekt, vikt och storlek. Rörrensningsmaskinen modellerades i Solid Edge, och vissa av delarna analyserades därefter i Ansys. Till rörrensningsmaskinens vajer konstruerades en växel som ska lösa problemen med vibrationer och värmeutveckling. En prototyptillverkning på denna växel gjordes för att testa om den löste problemen, vilket dock inte kommer att presenteras i denna rapport av konfidentiella skäl.This report will present a design study of a new development of a pipe cleaning machine, which is ordered by a company working in the plumbing industry. The design that has been developed consists of; a base structure made in plastic material, which can be mold casted in one piece, a module that places all the components inside the drum, telescopic handles which make the machine easy to store, and storage locations for additional accessories. The performance of the machine has been optimized by test studies and calculations, which has given the optimal power, weight and dimensions. The pipe cleaning machine was modeled in Solid Edge, and then imported into Ansys for further calculations. To solve problems with vibrations and heat generations along the wire, a gear was designed. This gear was later manufactured and tested to be able to verify that the described problems were solved. This part is, however, not included in this report for reasons of confidentiality.
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Rapley, Steve. "Computational investigation of torque on spiral bevel gears." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10803/.
Full textAbstract:
This thesis describes the development of a numerical modelling strategy for simulating the flow around a shrouded spiral bevel gear. The strategy is then applied to a series of parametric variations of key shroud parameters. The shroud and gear in question are generic, although based upon those employed in the internal gear box of a Rolls-Royce aeroengine. The need to shroud the gear comes from the fact that a spiral bevel gear, when rotated, acts like a fan. Work is done by the gear to move the surrounding fluid, usually air with oil particles suspended in it, which creates a parasitic loss, referred to as the windage power loss. The work within this thesis is part of a larger project which has investigated how windage power loss can be affected by geometric features of gears and shrouds. This is important as for large diameter (>200mm) bevel gears running at high speeds (>10,000 RPM) the windage power loss forms a substantial part of the total power loss. The modelling strategy has been developed in this work by studying 4 different fluid flow settings: Taylor-Couette flow, Conical Taylor-Couette flow, an unshrouded spiral bevel gear, and a shrouded spiral bevel gear. Work on Taylor-Couette flow provided a basic setting in which to trial various numerical techniques and gain familiarity with the commercial CFD program which would be used throughout this thesis (FLUENT), along with the meshing program GAMBIT. It gave an understanding of the flow, which was then used to simulate the flow in a modification of Taylor-Couette flow where the cylinders are replaced with cones, called Conical Taylor-Couette flow. Comparisons were made between 4 popular turbulence models, allowing a decision to be made on the `best' turbulence model to use in the modelling of a shrouded gear, and to start to develop the strategy. This strategy was then applied to the more complex geometry of an unshrouded gear, simulating experimental data which had been created on an in-house rig. To confirm the applicability of the strategy to modelling shrouded spiral bevel gears, it was applied to two shrouds for which experimental data was available. It showed that numerical modelling can capture the relative performance of the shrouds well. The work then continued by considering a series of parametric variations, whereby 3 key shroud parameters are each varied in 3 manners, producing 27 variations. Each of these parameters can affect the windage power loss: an assessment of how much each parameter affects windage power loss has been given. A description of the flow field in `good' and `bad' cases has been given, and through approximating the flow by using the compressible form of Bernoulli's equation, reasons for a `bad' shroud being `bad' have been presented.
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Molokanov, Aleksej. "Design of the high-strength gear steels for use in advanced power transmission for low-emission aero-engines." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7729/.
Full textAbstract:
The gear components in the aero-engine transmission system are subjected to very high stresses during service at elevated temperatures. Due to requirements of increasing power take-off and weight reduction further improvements in the high-strength gear steel are needed. The aim of this project was to design a new steel composition to give an increase in the core strength by 10 % compared to the currently used BS S 156 high-strength gear steel and increase the material capability to withstand higher operating temperatures of up to 300 oc. In addition to this, it was required that the new steel should also have similar or higher ductility, fracture and impact toughness, fatigue and wear resistance to the current steel, with minimal changes being allowed to the current heat treatment schedule. A final requirement was that the design process should also consider minimising the cost of the new steel composition through reducing the use of expensive alloying elements.
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Alharbi, Khalid Abdulkhaliq M. "The mechanical contact behaviour and tribology of polymer gears." Thesis, University of Warwick, 2018. http://wrap.warwick.ac.uk/103328/.
Full textAbstract:
Interest in using polymer gears has been growing dramatically in the last decade. Increasing understanding of their working behaviour has improved appreciation of their advantages compared to their limitations when selecting appropriate applications. However, restricted knowledge still leaves many unfulfilled areas that might benefit from their valuable advantages and control of their limitations, for example, in replacing. their metallic counterparts in more applications. Given their very different materials properties, it is important to develop bespoke design and rating methods for polymer gears, with properly validated rules, that are not mere modifications to metallic gearing rating methods. A major aim of this thesis is to provide a new deeper understanding for use when designing and rating some technologically important types of polymer gears for wider applications. Having identified an important research gap in polymer gearing theory and practice, this thesis covers mostly experimental studies involving continuously monitored wear and wear rate and microscopic evaluation of underlying tribologies. It examines the behaviour of polymer gears made of acetal, nylon (moulded and machine-cut) and polycarbonate, all common gearing materials, during and after running under different physically realistic conditions. Some modifications to test rigs uniquely designed to operate at a continually constant load enable study of surface thermal behaviour under dry and lubricated conditions and with simulations of moderate gear misalignments. In dry-running cases, gear load capacity and wear behaviour of different polymers and variations in underlying tribology all presented important relations between the gear tooth wear rate, the applied load and the tooth surface temperature. Quite similar patterns were seen under oil lubricated conditions. Typically, though, there was a nearly three-fold improvement in gear load capacity, the wear rate and gear tooth surface temperature were decreased, and SEM showed some changes in surface tribology. Finally, deliberately introduced angular misalignments between gear pairs indicated a reasonable tolerance of small but practical levels, with different tribological behaviours between the left and right sides of the tooth surfaces. A severe increase in wear rate and tooth failure arose from misalignments above 0.8ο yaw angle and 0.4ο pitch angle. After a unifying discussion, conclusions are drawn and further work is proposed for extended studies over different parameter ranges.
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Haddad, Charles Daoud. "The elastic analysis of load distribution in wide-faced helical gears." Thesis, University of Newcastle upon Tyne, 1991. http://hdl.handle.net/10443/3615.
Full textAbstract:
For a gear designer, the meshing gear tooth root bending stresses, and contact stresses are of major importance. To be able to obtain accurate values of these stresses, it is essential to determine the actual load distribution along the contact lines of the meshing gear tooth pairs. this load distribution. The objective of this work is to predict In the current gear design standards such as AGMA 2001¹, B5436², DIN3990³ and 150-0156336⁴the contact line load distribution is estimated by using a two-dimensional "thin slice" model of the meshing gear teeth. Clearly, this cannot account accurately for maldistribution of loading across the tooth face width, which is essentially a three-dimensional phenomenon. As a result, the effects of tooth lead, profile and pitch deviations are inadequately modelled. In this work, the elastic compliance of wide-faced helical gears of standard tooth form, zero addendum modification, and between 10 and 100 teeth, was determined using a 3-D finite element elastic model of the whole gear. These results were incorporated into a micro-computer program which calculates the load distribution across the meshing tooth pair faces. The effects of a number of parameters such as U, Z, b, and β* on the load distribution and contact stresses of an error-free gear were also investigated using the micro-computer program and the results were compared with other published data and those obtained from the standards²,³,⁴ Vedmar⁵ and Simon⁴³. The load peaks near the start and end of contact, attributed by some⁶,⁷ to the resistance of the unloaded portion of the tooth beyond the shorter contact lines in those regions, is very clearly demonstrated by Vedmar⁵, others⁶,⁷ and this work, but certainly not by the standards (this effect is usually referred to as the "buttressing" effect). The thin slice model largely over estimates the tooth mesh stiffness cγ since the convective effects of loading are completely ignored. The effects of lead deviations such as helix angle error and face crowning (barrelling), profile deviations such as profile angle error, profile crowning and tip relief, and pitch deviations such as adjacent base pitch error, were also studied. Their effect on the load distribution factors KH(3' KHO! and the overall load distribution factor KH, were obtained from the compared with the results from the standards2,3,4. micro-computer program and As expected, the standards considerably overestimate these factors due to their overestimation of mesh stiffness. Nevertheless, the pattern of variation in the load distribution factors was similar. The theoretical predictions were compared with experimental results measured on wide-faced test gears (specifications given in Table 5.1) with known (measured) mounting and tooth form errors. Measurement of tooth root strains to determine the load distribution along the simultaneous contact lines showed that the experimental and theoretical results agreed on the average to within 3.5% (end of tooth results not included). Also the total applied load upon comparison with theory agreed to within 6%. Experimental absolute values of transmission error "ft" were not available, however, the pattern of variation of 11ft" during meshing showed excellent consistency with the theoretical results (variations were very small anyway and within the error band). A separate test however, which gave the approximate absolute transmission error (tooth misalignments and form errors not included) agreed to within 1 % with theory.
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Gurkan, Niyazi Ersan. "Non-linear Mathematical Modeling Of Gear Rotor Bearing Systems Including Bearing Clearance." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606798/index.pdf.
Full textAbstract:
ABSTRACT
NON-LINEAR MATHEMATICAL MODELING
OF GEAR-ROTOR-BEARING SYSTEMS
INCLUDING BEARING CLEARANCE
GÜRKAN, Niyazi Ersan M.S. Department of Mechanical Engineering Supervisor: Prof. Dr. H. Nevzat Ö
ZGÜ
VEN November 2005, 130 pages In this study, a non-linear mathematical model of gear-rotor systems which consists of elastic shafts on elastic bearings with clearance and coupled by a non-linear gear mesh interface is developed. The mathematical model and the software (NLGRD 2.0) developed in a previous study is extended to include the non-linear effects due to bearing clearances by using non-linear bearing models. The model developed combines the versatility of using finite element method and the rigorous treatment of non-linear effect of backlash and bearing clearances on the dynamics of the system. The software uses the output of Load Distribution Program (LDP), which computes loaded static transmission error and mesh compliance for the contact points of a typical mesh cycle, as input. Although non-varying mesh compliance is assumed in the model, the excitation effect of time varying mesh stiffness is indirectly included through the loaded static transmission error, which is taken as a displacement input into the system. Previous computer program which was written in Fortran 77 is rewritten by using MatLAB 7.0 and named as NLGRD (Non-Linear Geared Rotor Dynamics) Version 3.0. The program is highly flexible and open to further developments. The program calculates dynamic to static load ratio, dynamic transmission error, forces and displacements at bearings. The mathematical model suggested and the code (NLGRD version 3.0) are validated by comparing the numerical results obtained from the model suggested with experimental data available in literature. The results are also compared with those of previously developed non-linear models. The effects of different system parameters such as bearing stiffness, bearing clearance and backlash on the gears are investigated. The emphasis is placed on the interaction of clearances in bearings with other system parameters.
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Hulvej, Matúš. "Návrh výrobní technologie ozubeného hřídele převodovky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378867.
Full textAbstract:
The diploma thesis presents a design of a technical project: design of production technology for a pinion shaft of a gearbox and design of alternative technology. It focuses on the analysis of a component, the selection of materials, machines and tools, and the creation of a manufacturing drawing and technological process of the production. It is concluded by a technical-economic evaluation, based on which are both designs compared and evaluated which design is better for specific conditions.
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Govilkar, Siddhartha. "DEVELOPMENT OF A NEW TEST MACHINE FOR EXPERIMENTAL CONTACT FATIGUE INVESTIGATIONS OF SPUR GEARS." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555585277243502.
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Hu, Zedong. "An investigation into the wear and thermal-mechanical performance of polyacetal gears." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/99346/.
Full textAbstract:
Numerous concepts, national and commercial design standards developed and proved for metallic gears, now are being migrated over to polymer gears. However, it is uncertain whether the same procedures should apply and there is only limited data available to attempt a validation. Since wide mechanical and thermal properties’ discrepancies exist between metals and polymers, it is essential to develop and establish their individual investigation methods and science of design. The work presented in this thesis endeavours to bridge this gap between practical application and theory, through exploring advances in fundamental experimental investigation approaches and providing effective test data. New studies on wear and failure mechanisms, in addition to adopting the prevailing methods (i.e. SEM examining worn tooth surfaces), and inspecting wear debris are proposed and employed. Schemes are proposed for measuring the temperatures and velocities in the airflow surrounding the operating gears and gear bulk temperatures. Their use adds to the work for predicting surface temperatures of polymer gears. Deliberate misalignment is introduced to investigate. Wear and failure mechanisms of polyacetal gears at various loads and a speed of 1000 rpm are studied. Various regimes of wear debris and topographies of worn tooth surfaces are presented. The dynamic evolutions of wear, wear rate and the temperatures of airflow and the tooth body (bulk) are presented. It is found that transition temperatures are more reliable for assessing the gear wear compared to transition torques. Gross misalignment effects on the performance of polyacetal gears are investigated. Strikingly distinct topographies of worn tooth surfaces and regimes of wear debris are presented. It is indicated that polyacetal gears are most sensitive to pitch misalignment. Micro-cracks are noted near pitch points and tooth roots. Aerodynamic characteristics of operating gears are studied and an improved model is proposed. On the basis of it, methods for improving the durability of polyacetal gears are proposed. Further investigations on aerodynamics, thermal-mechanism and misalignment are recommended to gain a better temperature and wear prediction, and understanding of misalignment.
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Khaustov, Sergey. "Elastohydrodynamic lubrication and surface fatigue modelling of spur gears over the meshing cycle." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/95787/.
Full textAbstract:
This thesis presents a modern method to evaluate spur gears based on the transient elastohydrodynamic lubrication (EHL) emulation of the full meshing cycle, evaluating elastic stresses in the gear flanks, collecting the stress history and applying stress and strain-life methods to calculate fatigue parameters and cumulative fatigue damage, i.e. predicting the fatigue life taking measured surface roughness into account. The EHL model is formulated as the coupled system of the hydrodynamic Reynolds equation and the elastic deflection equation. These are solved simultaneously including the transient effect by incorporating the squeeze film term of the Reynolds equation with a Crank-Nicolson discretization of time. The finite difference discretisation of the elastic deflection equation utilises the differential form first formulated at Cardiff to allow coupling of the equations. The Reynolds equation can be discretised either by a finite difference or by a finite element method. The coupled system is solved simultaneously either by a narrow bandwidth Gaussian elimination or a Gauss-Seidel iterative method. The elastic stresses due to the superimposed discrete values of the EHL pressure and shear stress at the EHL mesh nodes are evaluated by carrying out the necessary convolution of the stresses by a Fast Fourier Transform method. The weighting functions required have been calculated analytically. The stresses are obtained on the EHL solution mesh and are interpolated to meshes fixed in the pinion and the gear flanks. They are then sorted and stored efficiently to enable fatigue life prediction algorithms to be applied. A detailed description of the EHL and the stress evaluation models are provided as well as a brief description of some fatigue life theories and calculations. The results of the complete analysis are provided for test gears obtained from the NASA Glenn laboratory fatigue tests and the Newcastle University Design Unit micro-pitting investigation. The analyses were carried out for real operating conditions from gear testing under extreme conditions. The surface roughness profiles used were real measured profiles taken from the test gears after initial running-in. The simulations reported are therefore as realistic as can be achieved and represent the true mixed lubrication conditions occurring in heavily loaded gears. The research also shows the importance of precise alignment of the roughness profiles in these conditions.
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Burns, Angela D. "Comparison of two electrofishing gears (backpack and parallel wires) and abundances of fishes of the upper Greenbrier River drainage." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5165.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains vii, 65 p. : ill., maps (part col.). Includes abstract. Includes bibliographical references.
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Miyasato, Hugo Heidy 1986. "Simulação do fenômeno de gear rattle em modelos de trem de potência automotivos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263727.
Full textAbstract:
Orientador: Milton Dias JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-17T18:54:27Z (GMT). No. of bitstreams: 1 Miyasato_HugoHeidy_M.pdf: 3357683 bytes, checksum: 9fcd8bd237500580084498c606879165 (MD5) Previous issue date: 2011
Resumo: Fenômenos de ruído, vibração e sua severidade (NVH) são uma grande preocupação da indústria automotiva desde o século 20. A fim de atingir uma vantagem competitiva, as montadoras têm se focado na melhora do desempenho de NVH dos seus produtos para lidar com um cenário de mercado global competitivo. No intuito de verificar o comportamento do sistema durante o processo de desenvolvimento, métodos computacionais são aplicados para encontrar melhores abordagens e na previsão de problemas, economizando tempo e orçamento da empresa gastos na construção de protótipos e testes. Nesse trabalho, gear rattle, um ruído induzido por impacto cuja causa são as engrenagens sem carga da transmissão, será modelado e simulado. É diagnosticado com maior intensidade em veículos com motores diesel em marcha lenta e excitado especificamente quando uma faixa de frequências que causa grande amplitude de vibração nos elementos internos da caixa de câmbio é alcançada. Modelos lineares do trem de potência em ponto morto ou em tração serão estudados, compreendendo as suas características básicas, tais como frequências naturais e modos associados que podem ser representativos do fenômeno. Esse sistema possui elementos com fortes não-linearidades, tais como a rigidez estratificada com histerese da embreagem e a folga entre os dentes dos engrenamentos. Uma caracterização mais realista será incluída no modelo com uma rigidez variante no tempo para o engrenamento helicoidal, utilizado em todas transmissões manuais, com uma componente dissipativa adequada aos impactos. Para verificar condições de operação que podem somente ser avaliadas segundo formulação não-linear, simulações serão realizadas para verificar a eficácia de orientações de solução e propostas de modificação encontradas na literatura
Abstract: Noise, Vibration and Harshness (NVH) phenomena are a great concern of the automotive industry since the twentieth century. In order to achieve a commercial advantage, manufacturers have focused on improving the NVH performance of their products to cope with a competitive global market scenario. To verify the behavior of the system during the design process, computational methods are applied to find a better approach and foresee problems, saving company budget and time spent in prototypes and tests. In this work, gear rattle, a impact-induced noise caused by the unloaded gear teeth inside the gearbox, will be modeled and simulated. It is diagnosed with a higher intensity in diesel vehicle engines at idle speed and in a more specific way excited when a range of frequency that causes large amplitude of vibration in the internal elements of the gearbox is reached. Linear models of the powertrain operating in idle and traction will be studied, in order to understand its basic characteristics, such as natural frequencies and associated vibration modes that could be representative to this phenomena. This system has elements with strong nonlinearities such as the stratified stiffness with hysteresis of the clutch and the backlash between the gear teeth. A more realistic feature will be included in the model with a time variable stiffness for the helical gear mesh, used in all manual transmissions, with a suitable dissipative component for the impacts. To verify operational conditions which can only be evaluated with nonlinear formulation, simulations will be made to verify the effectiveness of solution guidelines and modification procedures found in literature
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
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Pruša, Lubomír. "Konstrukční návrh manipulátoru obrobků." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230427.
Full textAbstract:
This master’s thesis deals with design of manipulator which manipulate the types of shift forks 1/5, 2/4, 3/7 and 6/R. The machine takes parts from the belt, which transports them from mark station. Parts are moved to the straightening machine by manipulator. Straightened parts are transported on the storage place, from which are sorted into the boxes and palletized by robot. As a part of work is the proposal of alternativ solutions, selecting the best solution, the design of the chosen variant and technical calculations of the main parts of the manipulator. The work includes the accompanying drawings, assembly drawings and 3D model.
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Lou, Kaiyan. "Syntheses of novel antitumor 1,4-anthracenediones and functionized cyclododeciptycene based molecular gears." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/883.
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Ozturk, Fatih Mehmet. "Optimum Design Of Multistep Spur Gearbox." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606749/index.pdf.
Full textAbstract:
Optimum design of multistep gearbox, since many high-performance power
transmission applications (e.g., automotive, space industry) require compact volume,
has become an important interest area. This design application includes more
complicated problems that are not taken into account while designing single stage
gear drives. Design applications are generally made by trial and error methods
depending on the experience and the intuition of the designer.
In this study, using Visual Basic 6.0, an interactive program is developed for
designing multistep involute standard and nonstandard spur gearbox according to the
American Gear Manufacturers Association (AGMA) Standards 218.01 and 2001-
B88. All the equations for calculating the pitting resistance geometry factor I, and
the bending strength geometry factor J, are valid for external spur gears that are
generated by rack-type tools (rack cutters or hobs). The program is made for twostage
to six-stage gear drives, which are commonly used in the industry.
Compactness of gear pairs and gearbox, and equality of factor of safety against
bending failure is taken as the design objective. By considering the total required
gear ratio, the number of reduction stages is input by the user. Gear ratios of every
stage is distributed to the stages according to the total gear ratio that satisfies the
required precision (from ±0.1 to ±
0.00001 on overall gear ratio) depending on the user selected constraints (unequal gear ratio for every stage, noninteger gear ratio e.g.). Dimensional design is determined by considering bending stress, pitting stress, and involute interference constraints. These steps are carried out iteratively until a desirable solution is acquired. The necessary parameters for configuration design such as number of teeth, module, addendum modification coefficient, are selected from previously determined gear pairs that satisfies the constraints by user interaction considering the performance criterion from the developed program. The positions of gears and shafts are determined automatically in order to keep the volume of gearbox as minimum while satisfying the nonlinear spatial constraints (center distance constraint for proper meshing of gear pairs, face distance constraint for proper assembly of pinion and gear having same shaft, gear interference constraint for preventing interferences between gears, shaft interference constraint for preventing interferences between gears and shafts) by using DLL (Dynamic Link Library) technology of Lingo 8.0 optimization software together with Visual Basic 6.0. If shaft interference constraint is removed then cantilevered mounting of gear pairs would also be possible, otherwise the gears should be mounted between bearings. Visual output of assembly is made by using Autodesk Inventor 7.0, automatically by the program.
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Богачов, О. О. "Удосконалення технологічного процесу виготовлення вала-шестерні конічної 5206-4205.05-Б домкрата установчого шляхом підвищення стійкості різального інструменту на зубофрезерній операції." Master's thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/72562.
Full textAbstract:
Кваліфікаційна робота магістра: 136 с., 27 рис., 23 табл., 60 джерел.
На сьогоднішній день продуктивність механічної обробки деталей машин багато в чому залежить від стійкості ріжучого інструменту. Поломки інструментів збільшують поза-циклові витрати часу і як наслідок знижують коефіцієнт використання обладнання.
Саме тому з’явилась необхідність удосконалення різального інструменту шляхом нанесення захисного покриття на ріжучу частину інструменту.
Мета роботи полягає в доведенні ефективності застосування захисного покриття.
При цьому повинні бути вирішені такі задачі як варіантний вибір способу виготовлення заготовки; проектування маршруту механічної обробки; визначення оптимальних режимів різання; доцільність застосування того чи іншого обладнання.
Об’єктом дослідження є технологічний процес виготовлення деталі вал-шестерня конічна.
Предметом дослідження є методи підвищення стійкості різального інструменту в процесі механічної обробки.
Наукова новизна одержаних результатів – запропоновано застосування захисного покриття методом електроіскрового легування для покращення ефективності ріжучого інструменту в процесі обробки вала-шестерні конічної на зубофрезерній операції.
Практичне значення отриманих результатів полягає в удосконаленні характеристики ріжучого інструменту в процесі механічної обробки.Квалификационная работа магистра: 136 с., 27 рис., 23 табл., 60 источников. На сегодняшний день производительность механической обработки деталей машин во многом зависит от стойкости режущего инструмента. Поломки инструментов увеличивают вне цикловые затраты времени и как следствие снижают коэффициент использования оборудования. Именно поэтому появилась необходимость усовершенствования инструмента путем нанесения защитного покрытия на режущую часть инструмента. Цель работы заключается в доказательстве эффективности применения защитного покрытия. При этом должны быть решены следующие задачи как вариантный выбор способа изготовления заготовки; проектирования маршрута механической обработки; определение оптимальных режимов резания; целесообразность применения того или иного оборудования. Объектом исследования является технологический процесс изготовления детали вал-шестерня коническая. Предметом исследования являются методы повышения стойкости режущего инструмента в процессе механической обработки. Научная новизна полученных результатов - предложено применение защитного покрытия методом электроискрового легирования для повышения эффективности режущего инструмента в процессе обработки вала-шестерни конической на зубофрезерной операции. Практическое значение полученных результатов заключается в совершенствовании характеристики режущего инструмента в процессе механической обработки.
The master's qualification work: 136 pp., 27 pict., 23 tabl., 60 sources. To date, the performance of mechanical machining of machine parts largely depends on the stability of the cutting tool. Instrument breakdowns increase off-cycle time expenditures and, as a consequence, reduce the utilization rate of equipment. That is why there was a need to improve the cutting tool by applying a protective coating on the cutting part of the instrument. The purpose of the work is to prove the effectiveness of the application of protective coating. At the same time, such tasks should be solved as a variant choice of a method of manufacturing of a work-piece; design of the route of mechanical processing; determination of optimal cutting modes; expediency of the use of this or that equipment. The object of the study is the technological process of manufacturing the details of the gear-pinion cone. The subject of research is the methods of increasing the stability of the cutting tool in the process of machining. The scientific novelty of the obtained results - the application of protective coating by the method of electroscope doping has been proposed to improve the efficiency of the cutting tool in the process of processing the tapered shaft gear on the dental-mill operation. The practical value of the results obtained is to improve the characteristics of the cutting tool in the process of machining.
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Геть, Юрій Михайлович, and Yuriy Het. "Обґрунтування і розробка безступінчатого приводу головного руху і механізму зміни частоти обертання шпинделя свердлильного верстату." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2018. http://elartu.tntu.edu.ua/handle/lib/24144.
Full textAbstract:
Дипломна робота присвячена науково-технічній задачі, яка полягає в обґрунтуванні і розробці безступінчатого приводу головного руху і механізму зміни частоти обертання шпинделя свердлильного верстату.
В роботі здійснено динамічний розрахунок шпиндельного вузла, описано конструкцію коробки швидкостей варіатора та прискорювальної головки.
В роботі проведено пошук можливості створення на базі вертикально- свердлильного верстату з безступінчастою механічною системою на основі включення в кінематичний ланцюг механічного варіатора. Проведено пошук і опис конструкції верстату, його конструктивних параметрів.
Конструкція виявилась економічно ефективною і доцільною. Виконано конструкторські розрахунки окремих елементів лінії приводу головного руху, зокрема шпиндельного вузла .
Виконано також розробку конструкції високошвидкісної головки, яка розширює технологічні можливості даної групи.
Подано необхідні техніко-економічні розрахунки, які підтверджують доцільність виконання даної роботи.The graduation thesis deals with the scientific and technical problem involving the substantiation and development of the variable-speed drive of the principal movement and mechanism for changing the spindle rotational speed of the drilling machine. The dynamic calculation of the spindle unit was carried out, the structure of the variable-speed gear box and the acceleration head were described in this work. The investigation of the possibility for the construction on the base of vertically oriented drilling machine with variable-speed mechanical system on the basis of the implementation of mechanical variable-speed drive in kinematic chain is carried out in this work. The research and description of the machine tool structure, its design parameters are given. The construction design proved to be cost effective and reasonable. The design calculations of the certain elements of the driveline of the principal movement, particularly of the spindle unit, are performed. The design of the high-speed head improving technical capabilities of the given group is developed. The necessary technical and economic calculations proving the rationale for the given work are provided.
Вступ; Аналітичний розділ; Оптимізація схем формоутворення на проектованому верстаті і оптимізація його компонувальної схеми; Вибір та обґрунтування вихідних даних на розробку верстатного обладнання; Технологічний розрахунок; Проектування конструкції верстатного обладнання; Науково-дослiдний роздiл; Спеціальний розділ, обґрунтування економічної ефективності прийнятих рішень; Охорона праці та безпека в надзвичайних ситуаціях; Екологія; Висновки