Дисертації з теми "High-speed bearings"
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Frew, David Anthony. "The design, development and vibration analysis of a high-speed aerostatic bearing." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/362.
Повний текст джерелаKarthikeyan, Bindu Kumar. "Tribo-dynamics of high speed precision spindle bearings." Thesis, Loughborough University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547399.
Повний текст джерелаPu, Guang. "Hybrid air bearings for high speed turbo machinery." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7789/.
Повний текст джерелаWasson, Kevin L. (Kevin Lee). "Hydrostatic radial bearings for high speed precision machine tool applications." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12287.
Повний текст джерелаWong, Chee Wei 1975. "Design, fabrication, experimentation and analysis of high-speed microscale gas bearings." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8876.
Повний текст джерелаIncludes bibliographical references (p. [183]-190).
Microengine Program. The all-silicon device consist of a free-rotating microturbine, with 4.2 mm rotor diameter, enclosed within a five wafer fusion-bonded stack. Of note are the low aspect ratio journal bearing and large journal bearing clearances, primarily limited by microfabrication, from which stable bearing operation must first be demonstrated as viable. Theoretical modeling of the gas-lubricated hydrostatic journal bearing presents design charts, a comparative study of existing predictions and investigation into rotational effects to consider the bearing stiffness during operation. Continued experimental refinements and exploration with our microfabricated rotor achieved rotational speeds up to 1.4 million rpm and peripheral speeds in excess of 300 m/s. Extensive experimental data is presented with analysis, focusing on whirl motion and its harmonic resonances as candidates for instability. Causes of ultimate failure is suggested with recommendations for further improvements. Moreover, in an effort to accomplish self-sustained microbearings, the axial thrust bearing is redesigned for a self-acting spiral groove bearing. The chosen constraint is to incorporate the hydrodynamic thrust bearing with minimal changes to the current device, whilst providing the required load and stiffness. Stability analysis and rarefaction considerations on the optimized design suggests an operating range for the bearing, leading to a hybrid design for ample stiffness during initial operation. The design is then developed into a microfabrication process flow and implemented successfully into the MicroBearing test devices. Experiments on a hybrid bearing were performed to gage the spiral grooves characteristics. A purely hydrodynamic aft thrust bearing device is then tested for operation through low speeds, although the effects of the spiral grooves could not be accurately determined. Finally, transition to a hydrodynamic operating mode for a hybrid bearing is demonstrated.
by Chee Wei Wong.
S.M.
Orr, Doyle Jay 1969. "Macro-scale investigation of high speed gas bearings for MEMS devices." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9268.
Повний текст джерелаIncludes bibliographical references (p. 309-315).
A macro-scale experimental test facility for investigating high-speed gas bearings for MEMS devices such as the MIT Micro-Engine is presented along with results from subsequent experiments. It is shown that the bearings required by such MEMS devices fall outside the usual range of design parameters for conventional gas lubrication systems. Due to the unorthodox design of the bearings, a new "hybrid" mode of operation is introduced along with the traditional hydrodynamic regime. The new hybrid mode is exploited to implement a novel in-situ rotor balancing scheme which enables hydrodynamic operation. Analysis for both modes of operation is presented along with experimental results. A high-order, efficient scheme for computing both the steady and unsteady hydrodynamic properties of the fully coupled, rotor/gas film dynamical system is presented along with comprehensive calculations for this class of plain, cylindrical, gas journal bearing. The scheme is then used to perform a generalized eigenvalue analysis on the compressible, unsteady system which reveals a new type a hydrodynamic instability. From a fundamental understanding of the bearing physics, strategies for operating MEMS devices with this class of bearing are deduced and minimum requirements for the accompanying measurement systems are established. Ancillary issues such as axial equilibrium of the rotor are discussed in detail.
by Doyle Jay Orr, Jr.
Ph.D.
Martin, M. J. "Elastohydrodynamic films and scuffing behaviour in high speed angular contact ball bearings." Thesis, Cardiff University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543267.
Повний текст джерелаGao, Wenjun. "Modelling of windage and churning losses in high speed rolling element bearings." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI048/document.
Повний текст джерелаIn a rotating machinery system like turbine engine, high speed rolling element bearings play an important role in supporting the rotating shaft or rotor, and need lubrication to insure their function. Except a small quantity of oil is needed to form the elastohydrodynamic lubricant film in the contact zone, most of lubricant remains in suspension in air, forming an oil/air mixture. This phenomenon leads to excessive parasitic hydraulic losses when rolling elements translate and rotate into the fluid environment, which may constitute a relatively large portion of the bearing's total power loss, named windage drag and churning losses. For high speed applications, i.e. for rotational speed up to 3× 10^6 Ndm, the contribution of drag/windage loss to the total one may reach up to 50%. However, so far there are few approaches used directly for drag and churning losses estimation, which could only provide a rather gross approximation. In this thesis, the Computational Fluid Dynamics (CFD) method is employed to analyze first the flow around one finite-length circular cylinder with two free ends in an open space. Then the model is changed to several in-line circular cylinders sandwiched by two flat walls, which represents a simplified approach. The fluid here is regarded as incompressible, representing an equivalent one-phase fluid for the oil/air two-phase flow inside the bearing cavity with specified fluid properties. The results indicate that the flow around the finite length roller element is perturbed by its two free ends, the surrounding rings, the cage and other rolling elements. A relationship between the drag coefficient and the Reynolds number suitable for circular cylinder in roller bearings (1
Kim, Tae Hyun. "Fatigue of surface engineered steel in rolling-sliding contact." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325019.
Повний текст джерелаRodriguez, Colmenares Luis Emigdio. "Experimental frequency-dependent rotordynamic coefficients for a load-on-pad, high-speed, flexible-pivot tilting-pad bearing." Texas A&M University, 2003. http://hdl.handle.net/1969.1/138.
Повний текст джерелаKamf, Tobias. "High speed flywheel design : Using advanced composite materials." Thesis, Uppsala universitet, Elektricitetslära, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-181256.
Повний текст джерелаKEHLENBACH, JOSUA. "Fault diagnosis of axlebox roller bearings of high speed rail vehicles based on empirical mode decomposition and machine learning." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299774.
Повний текст джерелаAxelbox lager är en av de viktigaste komponenterna i ett järnvägsfordon när det berör säkerheten. Ett axelbox lager som havererar under drift kan vara farligt for passagerarna och även dyrt för operatören. Driftfel av lagren har varit orsaken till många katastrofala olyckor. Därför är det av yttersta vikt att förutsäga lagerfel så tidigt som möjligt. Detta ökar fordonets tillförlitlighet och säkerhet samt minskar underhållskostnaderna. Mycket forskning har utförts inom övervakning av rullager. Många metoder använder komplexa algoritmer för att maximalt utnyttja matningarna. Algoritmerna saknar ofta tolkbarhet och har höga beräkningskostnader, vilket gör dem svåra att använda i ett integrerat system. Denna avhandling kombinerar era metoder för databehandling och maskininlärning till en algoritm som kan förutsäga lagerskador med hög precision, samtidigt som tolkningsförmågan bibehalls. Bland andra välkända metoder sa använder algoritmen Empirical Mode Decomposition (EMD) och Singular Value Decomposition (SVD) för att extrahera väsentlig information for vibrationsmätningarna. Algoritmen testas sedan med tre olika vibrationsdatamängder, varav en mättes specikt med tanke på simulering av axelbox lager. Ett annat mål med algoritmen är att göra den tillämpad för ytterligare mätningar. Det bör vara möjligt att inkludera mätningar av olika slag, dvs ljud- eller temperaturmätningar, och därigenom förbättra resultaten. Detta skulle minska implementeringskostnaden avsevärt eftersom befintliga sensorer används för detta ändamål. I händelsen av att de föreslagna metoderna inte fungerar med nya mätningar är det även möjligt att integrera ytterligare funktioner i algoritmen.
Rowan, D. "Design and development of a high-speed test facility and the measurement of the fluid film characteristics of journal bearings." Thesis, Cranfield University, 1998. http://dspace.lib.cranfield.ac.uk/handle/1826/11357.
Повний текст джерелаSabirin, Chip Rinaldi [Verfasser]. "Digital Control for Active Magnetic Bearings in High-Speed Permanent-Magnet Synchronous Machine with 40000 rpm and 40 kW / Chip Rinaldi Sabirin." Aachen : Shaker, 2014. http://d-nb.info/106619789X/34.
Повний текст джерелаWei, Sicong. "A 3D Sliding Bearing Finite Element Based on The Bouc-Wen Hysteretic Model : Mathematical modelling and numerical implementation." Thesis, KTH, Bro- och stålbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289480.
Повний текст джерелаNiel, Dimitri. "Etude du comportement thermomécanique de paliers à roulements pour une application hautes vitesses." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI007/document.
Повний текст джерелаRolling Element Bearing (REB) is an essential component in mechanical transmission to reduce friction between rotating parts. Now, with the development of electrical motor in mechanical industry, REBs may work at very high rotation speed. It leads to an increase of REB power losses and temperatures. Theses power losses are strongly coupled with the REB thermal behaviour. The oil temperature has a significant impact on the kinematic viscosity which in turn affects the REB power losses. Based on thermal network approach, an intermediate model is developed in this study. This new model allows obtaining lumped information (temperature of rings) with a minimum of input data (REB external geometry and operating condition only) and by using global power loss models. This intermediate model is developed for angular contact ball bearing and deep groove ball bearing under oil jet lubrication for high speed application. Experimental data are required to validate this new approach. That why, a modular test rig is designed to obtain information on the REB thermomechanical behaviour. The new test rig developed in this study is dedicated to a wide range of REB dimensions and for different operating conditions. For the first test, a deep groove ball bearing under oil jet lubrication is studied for high speed application ((N.dm) product is higher than one million.)
Ashman, D. "High-speed performance of a hydrostatic thrust bearing." Thesis, University of Wolverhampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378961.
Повний текст джерелаNimir, Yassin Lutfi. "An air bearing system for high speed turbomachinery." Thesis, University of Sussex, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385143.
Повний текст джерелаMondscehin, Brian David. "Evaluation of Alternate Bearing Designs in a High Speed Automotive Turbocharger." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/33513.
Повний текст джерелаMaster of Science
Schneider, Abraham 1981. "Dynamic modeling of high-speed impulse turbine with elastomeric bearing supports." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89911.
Повний текст джерелаSamadli, Vugar. "Rotor-bearing system dynamics of a high-speed micro end mill spindle." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015756.
Повний текст джерелаMarais, Charl Henri. "High speed flexible rotor active magnetic bearing control / by Charl Henri Marais." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1084.
Повний текст джерелаThesis (M. Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2006.
Alsaeed, Ali A. "A Study of Methods for Improving the Dynamic Stability of High-Speed Turbochargers." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26664.
Повний текст джерелаPh. D.
Dyson, John Edwin. "Aspects of the behaviour and design of dental high speed ball bearing air turbine handpieces." Thesis, University of London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324587.
Повний текст джерелаBailey, Nicola Y. "Analysis of dynamical performance and contact for a high speed thrust bearing including slip effects." Thesis, University of Nottingham, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.727115.
Повний текст джерелаGarratt, John Edward. "Mathematical modelling of air-rotor-stator interactions in high-speed air-riding bearing and seal technology /." Thesis, University of Nottingham, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.580292.
Повний текст джерелаAl-Ghasem, Adnan Mahmoud. "Measurement of rotordynamic coefficients for a high-speed flexure pivot tilting-pad bearing(load between pad) configuration." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2415.
Повний текст джерелаWroblewski, Adam C. "Model Identification, Updating, and Validation of an Active Magnetic Bearing High-Speed Machining Spindle for Precision Machining Operation." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1318379242.
Повний текст джерелаMessager, Gael [Verfasser], Andreas [Akademischer Betreuer] Binder, and Ulrich [Akademischer Betreuer] Konigorski. "Self-bearing permanent magnet synchronous machine configurations and control for high-speed applications / Gael Messager ; Andreas Binder, Ulrich Konigorski." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2019. http://d-nb.info/1199006467/34.
Повний текст джерелаLee, Trevor J. "Investigation of ASTM E 238 Bearing Pin Properties for Various Aerospace Alloys." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1074.
Повний текст джерелаCalderon, Salmeron Gabriel Benjamin. "Enabling More Efficient E-Mobility : Grease Development by a Novel Bearing-Grease Test Machine." Thesis, KTH, Maskinkonstruktion (Avd.), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259672.
Повний текст джерелаInförandet av elfordon i bilindustrin utgör en möjlighet för smörjfettproducenter. Olika hastigheter, belastningar och elektriska förhållanden är närvarande i de elektriska fordonens kullager i jämförelse med förhållandena i ett traditionellt förbränningsmotorfordon. Detta kräver utveckling av nya fetter som kan hantera de utmaningar som uppkommer med denna nya teknik. Detta projekt ämnar jämföra två fettförtjockningstekniker genom att installera, utveckla och validera en ny höghastighetslagermaskin (HSBT-maskin) för smörjfettstestning. Denna maskin möjliggör att förhållanden som finns i lagren hos ett elektriskt fordon kan efterliknas. I denna masteruppsats användes spårkullager med beteckningen 6208 för att jämföra smörjfettens mekaniska prestanda. I denna studie jämfördes litiumkomplex- och polypropenfetter genom att analysera friktionsmomentet och den självinducerade temperaturen för de testade kullagersmörjfettskombinationerna. Resultatet av studien visar energibesparingspotentialen för båda smörjfetterna och visar möjligheten att använda HSBT-maskinen för att testa smörjfetter. Detta projekt är det första steget i en ambitiös plan att förbättra e-mobilitet genom smörjfettsforskning. Studien ger indata för framtida utveckling av elektriska maskiner och bidrar till skapandet av nya standarder för testning av fetter för elektriska fordon.
Pavluš, Ondřej. "Návrh elektrodynamického magnetického ložiska." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442790.
Повний текст джерелаHorn, Maik [Verfasser]. "Untersuchungen zur praktischen Umsetzung von Elastomer-Lagersitzen in Hochdrehzahl-Traktionselektromotoren : Studies for the practical implementation of elastomer supported bearing carriers in high-speed traction electric motors / Maik Horn." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1204458782/34.
Повний текст джерелаLee, Seong-Ryeol, Florian Schoemacker, Christian Stammen, and Katharina Schmitz. "Numerical and experimental study on novel hydraulic pump concept." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71110.
Повний текст джерелаChen, Cheng-Yuan, and 陳政原. "Design of 5-DOF High Speed Spindle Supported by Magnetic Bearings." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/16763475358699444462.
Повний текст джерелаCHIOU, JIIN-HORNG, and 邱錦宏. "STUDY OF APPLICABILITY OF ISOLATION BEARINGS IN HIGH-SPEED RAILWAY BRIDGES." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/27882095666401916498.
Повний текст джерела國立臺灣大學
土木工程學系
86
This study investigates the axial and vertical displacements of decks, base shear and moments of piers,axial stresses of rails at expansion joints and responses of bearings of high-speed railway bridges using lead rubber bearings and laminated rubber bearings to study the applicability of those bearings in high-speed railway bridges. This study relies mainly on numerical analysis. A finite-element analysis program is developed as the analysis tool. The models adopted and various parameters used are derived in the paper. The responses of high-speed railway bridges using bearings are analyzed and are compared to responses of those that are not equipped with bearings to study the applicability of bearings. The results show that the base shear and moments of high-speed railway bridges using lead rubber bearings subjected to acceleration and braking forces of vehicles,seismic loads and temperature loads are significantly reduced and displacements of decks and rail stresses remain roughly the same as those of high-speed railway bridges using hinges and rollers. Application of lead rubber bearings in high-speed railway bridges is considered applicable. And the excessive longitudinal displacements of decks using laminated rubber bearings subjected to acceleration and braking forces should be noted.
吳明得. "Multilevel optimization of the high-speed spindle system with magnetic bearings." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/14164660800968411890.
Повний текст джерела國立中正大學
機械系
89
ABSTRACT A design algorithm of single objective and/or multilevel optimization of a high-speed spindle system with magnetic bearings under critical speeds constraints are developed in this study. In the process of designing the high-speed spindle system, the weight of spindle and the vibration of tip cutter play very important roles on the performance of the high-speed spindle. Hence, the objective functions of optimization include the total weight of the spindle and/or the vibration of tip cutter. Consider the high-speed spindle system of this thesis, magnetic bearings are introduced to displace the ball bearing of the high-speed spindle system, which had been developed in the National Chung-Cheng University. To achieve the optimization approach, the system equations of motion are first derived from Lagrange Method and Finite Element Method (FEM). Then the system natural frequencies, mode shapes, and steady-state response are determined by the numerical analysis. Furthermore, from the influences of system parameters on the dynamic behaviors of the system, the radius of the outer shaft, the bias currents of the magnetic bearings, and the position of the bearings and disks, are considered as the design variables of optimization. According to the objective functions, both the optimization of single objective and multilevel objective optimization with critical speeds and/or bending stresses constraints are discussed. Thus, the optimization techniques employed are the Sequential Quadratic Programming Method (SQP) and the Goal Attainment Method (Att.Goal). The optimum results indicate that the total weight of the spindle and/or the vibration of the tip cutter of the high-speed spindle with magnetic bearings can be significantly reduced by single objective optimization or multilevel optimization under the critical speeds and/or bending stress constraints.
Kasarda, Mary E. F. "The measurement and characterization of power losses in high speed magnetic bearings /." 1997. http://wwwlib.umi.com/dissertations/fullcit/9724685.
Повний текст джерелаGao, Chih-Chung, and 高志忠. "The Performance of High-Speed Ball Bearings with Oil-Air Lubrication System." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/86494706958269375700.
Повний текст джерела國立中正大學
機械工程學系
85
The ball bearing is widely used on many high speed rotating systems due to its low starting friction and high load capacity. However, heat generating and dynamic loading caused by high speed operation have been the limiting factors for increasing the speed limit of many high speed ball bearing applications. Therefore, how to provide proper lubrication and preload to reduce heat generation effectively are major task for high-speed ball bearing operation.Recently, oil-air lubrication has been used on high-speed ball bearing because of precise oil quantity control and high cooling efficiency. However, the fluctuation of oil supply resulted from the periodic oil feeding is unfavorable. In this study, the measuring equipment of fluctuation of oil supply was established. The operation parameters affecting stability of oil supply of oil-air lubrication system are experimentally studied. A test rig for high-speed ball bearings was also developed. The stable oil supply conditions obtained from preceding experiments is applied to bearing tests. The performance of high-speed ball bearing under different preload, running speed and oil flow rate has been investigated by measuring temperature rise and friction torque of test bearing.From this study, operating conditions that provide stable oil supply and good bearing performance were established. The effects of bearing preload on bearing temperature rise was also presented. It is also demonstrated that the high-speed ball bearing test rig built in this study provides a useful tool to develop lubrication technology for high-speed rotating system.
Tsai, Shui-Fa, and 蔡水發. "Analysis of the Electromagnetic Forming for Small and High Speed Hydrodynamic Bearings." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/05040568992994217737.
Повний текст джерела國立雲林科技大學
機械工程系碩士班
91
For the increasing of small and high-speed motor requirement in electronic productions, the characteristics, low friction, low noise, and high speed, etc., of hydrodynamic bearings could satisfy the conditions. For this reason, hydrodynamic bearings are often used in disc drive or other rotational parts. The hydrodynamic bearing has a number of herringbone grooves on the inner diameter of the sleeve. Once the shaft starts to run, the grooves take in oil from each end of grooves and push it into the central part to produce pressure. Because of the sleeve and the shaft are not in contact. The hydrodynamic bearings offer several advantages such as high speed, low friction and low noise. There are some great advantages of using Electromagnetic forming, such as high speed, good repeatable, low springback, inexpensive, small size and high flexibility. Electromagnetic forming could be developed to manufacture the grooves of hydrodynamic bearing in high speed. The objective of this study is to discuss the effect of various parameters in fabrication of hydrodynamic bearings via the commercial FEM code DEFORM-3D. From the results of simulation, the electric parameters could be evaluated for forming need.
Wang, Yan-Hsin, and 王彥欣. "Design and characteristic analysis of high speed spindle aerostatic circular double pad thrust bearings." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/46126537013464007358.
Повний текст джерела國立彰化師範大學
工業教育學系
89
The purpose of this paper is to make an investigation on the circular aerostatic thrust bearing with grooves and with different diameters presented by describing numerical methods in which Reynolds’ equation is solved in finite element form and on the other way the resistance network method (R.N.M.) based on the concept of flow continuation is obtained. The theoretical model developed is capable of calculating the pressure distribution in the gas-lubricated film and the load-carrying capacity as a separating force. Beside, to analyze the behavior on double-pad thrust bearing with eight restrictors for the high-speed spindle, and to estimate the pressure distribution in considered thrust bearing, numerical calculations were presented by the R.N.M. based on the concept of flow continuation. The coincidence of results derived from the R.N.M. and the F.D.M. based on the Reynolds’ equation has been proved. Finally, the aerodynamic effect caused by the high rotating speed of the spindle will be taken into account. The characteristic of load capacity is influenced by the spindle weight and the bearing inclination.
LI, JHE-YUAN, and 李哲淵. "Preparation and Design of The Magnetic Fluid and Magnetic Bearings on Ultra High Speed Seals." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/99pgvp.
Повний текст джерела-Yi, Ji, and 黃吉毅. "Modeling and Recognition of the Temperature Rise on the Bearings of the High-Speed Spindle System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/77073382881215551669.
Повний текст джерела國立高雄第一科技大學
機械與自動化工程所
97
The purpose of the thesis is to develop a forewarning system for indicating the abnormal temperature rise and vibration behavior of the bearing in the high-speed spindle in a motor system. As generally speaking, without well releasing the heat generated under the operation of a motor, the heat will seriously cause the rigidity degradation and aging on the bearing.Therefore, we have to do the calorific capacity analysis of the bearing under operating status,and then to build a more realistic model for simulating the temperature rise curve and the vibration behavior. In our purpose, we want to design a forewarning system to avoid the system operate out of the safety temperature range and to indicate the abnormal variation in advance. However, the mathematical model constructed out of the ideal geometric kinetics and thermodynamics is not enough for simulating the real motion of the bearing in the high-speed spindle system. Therefore, we monitor and record the temperature rise curve and vibration behavior of the bearing in the high-speed spindle system, and then input all the data into the back-propagation neural networks for simulation calculation. Then, we compare the temperature and vibration of the bearing monitored immediately with the simulated data out of the back-propagation neural networks calculation. When the deviation of the temperature or vibration is out of the safety range, our forewarning system constructed out of the fuzzy inference will deliver an alarm to users to protect the bearing against the damage from heat.
Lawrence, Tom Marquis. "Characterization and Measurement of Hybrid Gas Journal Bearings." 2012. http://hdl.handle.net/1805/2926.
Повний текст джерелаThis thesis concentrates on the study of hybrid gas journal bearings (bearings with externally pressurized mass addition). It differs from most work in that it goes back to “basics” to explore the hydrodynamic phenomena in the bearing gap. The thesis compares geometrically identical bearings with 2 configurations of external pressurization, porous liners where mass-addition compensation is varied by varying the liner’s permeability, and bushings with 2 rows of 6 feedholes where the mass-addition compensation is varied by the feedhole diameter. Experimentally, prototype bearings with mass-addition compensation that spans 2 orders of magnitude with differing clearances are built and their aerostatic properties and mass addition characteristics are thoroughly tested. The fundamental equations for compressible, laminar, Poiseuille flow are used to suggest how the mass flow “compensation” should be mathematically modeled. This is back-checked against the experimental mass flow measurements and is used to determine a mass-addition compensation parameter (called Kmeas) for each prototype bushing. In so doing, the methodology of modeling and measuring the mass addition in a hybrid gas bearing is re-examined and an innovative, practical, and simple method is found that makes it possible to make an “apples-to-apples” comparison between different configurations of external pressurization. This mass addition model is used in conjunction with the Reynolds equation to perform theory-based numerical analysis of virtual hybrid gas journal bearings (CFD experiments). The first CFD experiments performed use virtual bearings modeled to be identical to the experimental prototypes and replicate the experimental work. The results are compared and the CFD model is validated. The ontological significance of appropriate dimensionless similitude parameters is re-examined and a, previously lacking, complete set of similitude factors is found for hybrid bearings. A new practical method is developed to study in unprecedented detail the aerostatic component of the hybrid bearings. It is used to definitively compare the feedhole bearings to the porous liner bearings. The hydrostatic bearing efficiency (HBE) is defined and it is determined that the maximum achievable hydrostatic bearing efficiency (MAHBE) is determined solely by the bearing’s mass addition configuration. The MAHBE of the porous liner bearings is determined to be over 5 times that of the feedhole bearings. The method also presents a means to tune the Kmeas to the clearance to achieve the MAHBE as well as giving a complete mapping of the hitherto misunderstood complex shapes of aerostatic load versus radial deflection curves. This method also rediscovers the obscure phenomenon of static instability which is called in this thesis the “near surface effect” and appears to be the first work to present a practical method to predict the range of static instability and quantify its resultant stiffness fall-off. It determines that porous liner type bearings are not subject to the phenomenon which appears for feedhole type bearings when the clearance exceeds a critical value relative to its mass-addition compensation. The standing pressure waves of hydrostatic and hybrid bearings with the 2 configurations of external pressurization as well as a geometrically identical hydrodynamic bearing are studied in detail under the methodology of the “CFD microscope”. This method is used to characterize and identify the development, growth, and movement of the pressure wave extrema with increased hydrodynamic action (either increasing speed or increasing eccentricity). This method is also used to determine the “cause” of the “near surface effect”. A gedanken experiment is performed based on these results which indicates that a bearing with a “stronger aerostatic strength” component should be more stable than one with a low aerostatic strength component. Numerical instability “speed limits” are found that are also related to the hydrostatic strength of the bearing. The local conditions in the standing waves are characterized in terms of their local Mach number, Knudsen number, Reynolds number, and Taylor Number. It is concluded that low eccentricity bearing whirl can be attributed to the off load-line orientation of the bearing load force caused by the overlay of the hydrodynamic bearing standing wave onto the hydrostatic bearing wave of the hybrid bearing, whereas it is hypothesized that aperiodic and random self-excited vibration which occurs at high eccentricity, as reported in the literature, is probably due to shock waves, turbulence, near surface effect, and slip at local areas of the standing wave.
Yang, Pe-Hn, and 楊培亨. "Application of Taguchi Method to Roubust PID Controller Design for 5-DOF High Speed Spindle Supported by Magnetic Bearings." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/41446507171027652818.
Повний текст джерела國立交通大學
機械工程研究所
85
The dynamic characteristics of magnetic bearings are often suffered from many problems, such as nonlinearities, parameter variations and external disturbances. To solve these problems, we applied Taguchi method associated with the decentralized control to design a decentralized PID controller with robustness. The results show that the performance of the decentralized PID controller system is better than that of the decentralized PD control system in the ability of suppressing the external force except that chattering effect exists in the responses. In the study, the Taguchi method is employed to determine beast parameters in control rules for a decentralized PID control method. Two major characteristics of the Taguchi method are, firstly, the use of total possible combinations to estimate the main factor effect and some, not all, of the interaction. Secondly, signal-to-noise (S/N) ratios are used to evaluate the system performance of a system in the presence of noise factor, so that the performance can be made insensitive to noise factor. For control systems with uncertainty, the Taguchi method is found to be effective to improve system performance. Finally, we developed a current driver circuit for a high speed spindle with five degrees of freedom supported by magnetic bearings. The prototype is tested under various operating conditions. We found that the control performance fulfills our design specifications, which directly verify our design methodology.
Віцюк, Юлія Юріївна. "Забезпечення довговічності підшипників ковзання на основі міді та нікелю для удосконалення поліграфічних машин". Doctoral thesis, 2011. https://ela.kpi.ua/handle/123456789/829.
Повний текст джерелаLee, Yu-Han, and 李育翰. "Performance Analysis of High Speed Spindle Aerostatic Bearing." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/33149677830761626847.
Повний текст джерела國立成功大學
機械工程學系
89
In the study of gas bearing, how the pressure distribution and the precision of bearing rotation are precisely calculated is an important material for gas bearing design. In this work the theory and the precise analysis of bearing performance are presented. First, the mathematical model of gasflowing condition in the bearing is constructed. After the derivation and the simplification from Navier-Stoke Equation resulting the expected Reynold’s Equation. The combination of continuous equation and flow equation of orifice throttle is then substitute into Reynold’s Equation. Finally The resulting revised nonlinear Reynolds Equation with dimensionless is discretized by, using Newton’methed. The revised numerical iteratived method is then dopted to solve the problem. This method can be used to simulate the high eccentricity ratio journal, the high-speed noncircular journal, the thrust bearing and the non-plane slide bearing, etc.. The analysis can be treated as the fundamental to construct the performance analysis gas bearing. The performance of the static- and dynamic-pressure gas bearing can be analyzed by the constructed numerical model. It includes the analyses of film pressure distribution, friction, loading capacity, rigidity, flow rate of lubricative gas, and eccentricity ratio, etc.. With the appropriate design of precise rotating bearing, the results of this study could be provided as the fundamental of optimized design and analysis of bearing.
Chou, Lin-En, and 周麟恩. "Kinematic and Dynamic Analysis of High speed bearing system." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/11598946158393074505.
Повний текст джерела國立中山大學
機械工程學系研究所
89
The aim of this thesis is to analyze the kinematic and dynamic characteristics of a high-speed bearing system. The examined kinematic characteristics will include the maximal speed, fatigue life and stiffness of a bearing system. The stability and transmission force of a bearing system as well as the vibration of its shaft were the studied dynamic characteristics. These analyses were based on the kinemitics of bearing systems, rotor dynamics and elastohydrodynamic lubrication theory. According to these analyses, the interaction and consequence among these characteristics and the parameters of a bearing system will be explained. After these analyses, preliminary and simple design trends about a high-speed bearing system are going to be proposed.
Chang, tou koan, and 張圖寬. "Multiobjective Optimization of Rotor-Bearing System of High Speed Spindle." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/77709802722415909977.
Повний текст джерела國立中正大學
機械工程學系
85
The dynamic behavior and optimum design of rotor-bearing system of high speed spindle are studied in this thesis. It consists of the outer shaft and the inner shaft. The outer shaft is composed of the center shaft and the rotor of AC motor. And the inner shaft is the tool holder. The outer shaft is joined together with the inner shaft via two join points. The dynamic behavior of the rotor-bearing system is modeled by the finite element method. Then the system natural frequencies are determined by the numerical analysis. Because the mass of the outer shaft may be much greater than that of the inner shaft, the single rotor-bearing system is also used to compare the behavior of the dual rotor-bearing system. The system natural frequencies are measured to compare the numerical results. Furthermore, the system steady-state response is also studied. In optimization, the Augmented Lagrange Multiplier Method (ALMM) and Modified Method of Feasible Direction (MMFD) of mathematical programming method are applied in this study. Also, both the single objective optimization and the multiobjective optimization are performed and the optimum results are compared. The optimum results indicate that the steady-state response at the front bearing and/or the transmitted forces through the bearings can be significantly reduced by single objective optimization or multiobjective optimization.
Chen, Yubao. "Dynamic analysis and diagnostic monitoring for high speed spindle-bearing structures." 1986. http://catalog.hathitrust.org/api/volumes/oclc/15692404.html.
Повний текст джерелаTypescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 250-257).