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1
Litvin, F. L., J. C. Wang, R. B. Bossler, Y. J. D. Chen, G. Heath e D. G. Lewicki. "Application of Face-Gear Drives in Helicopter Transmissions". Journal of Mechanical Design 116, n. 3 (1 settembre 1994): 672–76. http://dx.doi.org/10.1115/1.2919434.
Testo completoAbstract (sommario):
The use of face-gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face-gears was described. Face-gear design is discussed. Topics included basic design geometry, tooth generation, limiting inner and outer radii, and recommendation for the gear ratio. Face-gear experimental studies were also included and the feasibility of face-gears in high-speed, high-load applications such as helicopter transmissions was demonstrated. Torque-split tests were performed and demonstrated an accurate split of torque using the face-gear concept.
2
Amir Mustafayev, Amir Mustafayev, e Chingiz Nasirov Chingiz Nasirov. "MATHEMATICAL EXPRESSIONS FOR TEMPERATURE IN THE CONTACT ZONE OF TEETH OF THE GEAR MECHANISMS". ETM - Equipment, Technologies, Materials 14, n. 02 (18 aprile 2023): 126–34. http://dx.doi.org/10.36962/etm14022023-126.
Testo completoAbstract (sommario):
Transmission gears are very widely used in modern machine building. Despite that electrical transmissions used in machine building industry, mainly mechanical transmissions are widely used in the industry. Because mechanical transmissions are independent and better than other transmisions. Distributing power between the transmission mechanisms and working units of various machines, changing the angle of momentum, by adjusting the speed of the parts, it is possible to change the type of movement, turn on and off the mechanism, change the direction of the transmission mechanisms. One of the most widespread types of transmission technology is the gear transmission. Tens of thousands of kilowatt-hours of gears can be transmitted. Advantages of gear transmission in comparison with others is their ability to maintain their reliability and long term functioning of the teeth, big value of the working coefficient (0,9 ÷ 0,99), simple construction, lack of special service, simplicity of the transmission number and compactness of dimensions. The missing aspects of these transmissions are high precision in their preparation and installation, and low noise level. The main criterion for the working ability of the closed gear transmissions is the contact endurance of the active surface of the tooth. For this reason, the main dimensions of the transmission are determined by the contact tension and by teeth bending. Keywords: gear wheel, tension, endurance, bending
3
Salamandra, Konstantin. "Static analysis and parameters synthesis of planetary-layshaft transmissions with three power flows". MATEC Web of Conferences 224 (2018): 02040. http://dx.doi.org/10.1051/matecconf/201822402040.
Testo completoAbstract (sommario):
The increase in the number of transmission ratios in the vehicles gearboxes leads to an increase in the number of mechanisms used and their complication. One way to obtain simple designs of multi-speed transmissions with smaller number of gears, clutches, brakes and synchronizers is to use combinations of planetary differential gears and gears with fixed axes (planetary-layshaft transmissions). The article presents a static analysis of a planetary-layshaft transmissions with three parallel power flows for obtaining the dependencies between the gear ratios of the internal mechanisms and the speed ratios of the transmission. A technique for determination the gear ratios of the internal mechanisms for providing a close to a given series of transmission ratios is described.
4
Mustafayev, Amir G., e Chingiz R. Nasirov. "A study of factors affecting wear and destruction of teeth in gear mechanisms". Nafta-Gaz 79, n. 9 (settembre 2023): 604–10. http://dx.doi.org/10.18668/ng.2023.09.06.
Testo completoAbstract (sommario):
Transmission gears are very widely used in the modern construction of the machine. Even though electrical transmissions are used, mainly mechanical transmissions are widely used in the machine building industry as they are independent and better than other transmissions. Distributing power between the transmission mechanisms and working units of various machines, by changing the angle of momentum by adjusting the speed of the parts, it is possible to change the type of movement, turn the mechanism on and off, and change the direction of the transmission mechanisms. One of the most widespread types of transmission technology is gear transmission. Tens of thousands of kilowatt-hours of gears can be transmitted. The advantages of gear transmission in comparison with others are their ability to maintain their reliability and long-term functioning of the teeth, high value of the working coefficient (0.90–0.99), simple construction, lack of special service, simplicity of the transmission number and compactness of dimensions. The missing aspects of these transmissions are high precision in their preparation and installation, and low noise level. The main criterion for the working ability of the closed gear transmissions is the contact endurance of the active surface of the tooth. For this reason, the main dimensions of the transmission are determined by the contact tension and by teeth bending.
5
Radzevich, Stephen P. "A Way to Improve the Accuracy of Hobbed Involute Gears". Journal of Mechanical Design 129, n. 10 (19 ottobre 2006): 1076–85. http://dx.doi.org/10.1115/1.2761919.
Testo completoAbstract (sommario):
Involute gears are widely used in the design of machines and mechanisms. Performance of gear transmissions, e.g., performance of automobile transmissions, strongly depends upon the accuracy of gears of which the transmission is comprised. The higher the gear accuracy, the higher performance of the gear transmission observed. An increase of accuracy of involute gears reduces vibration of the transmission, and causes lower noise excitation. A significant amount of gears for the needs of the automotive industry is manufactured by hobbing. Reported in this paper is a way to improve the accuracy of hobbed involute gears that requires an appropriate alteration of design parameters of the hob to be applied. The required correction of design parameters of the hob can be computed on the premises of in-depth analysis of kinematic geometry of meshing of the hob and of the work gear, i.e., of design parameters of the hob, as well as an analysis of kinematics of meshing of the gear work and of the hob. An analytical approach for computation of the required alterations in design parameters of the involute hob is reported in the paper. Using commercial software MathCAD/Scientific, numerous computer codes are developed for performing the necessary computations. A numerical example of computation is presented. The reported results of research are ready to put into production.
6
Maláková, Silvia, Matej Urbanský, Gabriel Fedorko, Vieroslav Molnár e Samuel Sivak. "Design of Geometrical Parameters and Kinematical Characteristics of a Non-circular Gear Transmission for Given Parameters". Applied Sciences 11, n. 3 (22 gennaio 2021): 1000. http://dx.doi.org/10.3390/app11031000.
Testo completoAbstract (sommario):
In this paper, the authors present the design of a suitable gear transmission with the continuously changing gear ratio in the range from 0.5 through 1.0 to 2.0 and back during one revolution of intermeshing gears, according to demands specified for a practical application. The gear train was designed as a pair of identical elliptical gears and the design procedure of the suitable pitch curve (ellipse) is described. The center of rotation of each of the gears is coincident with one of the pitch ellipse foci, so the gears are placed eccentrically. The gear teeth have involute profiles, but the involutes for the active and for the passive tooth sides are different. These are gears with an asymmetrical tooth profile. In the final part, the paper deals with kinematical characteristics of the designed non-circular gear transmission, which differ from the kinematical characteristics of standard circular gear transmissions with a constant gear ratio.
7
Brancati, Renato, Stefano Pagano e Ernesto Rocca. "Dynamic Behaviour of an Automotive Dual Clutch Transmission during Gear Shift Maneuvers". Applied Sciences 13, n. 8 (12 aprile 2023): 4828. http://dx.doi.org/10.3390/app13084828.
Testo completoAbstract (sommario):
The paper presents a model for the torsional dynamics of an automotive driveline equipped with a Dual Clutch Transmission (DCT), focusing on the gear rattle phenomenon arising during the transients of engagement and disengagement of the clutches, and during the synchronizing manoeuvres. This vibro-acoustic phenomenon, particularly annoying in automotive transmissions, can be accentuated by the presence of many unloaded gears in this type of gearbox. Dual Clutch Transmission systems are today largely diffused in the car automatic transmissions, permitting fast gear shifts and avoiding the interruption of the drive torque. The study is conducted by adopting a tribo-dynamic model with lumped parameters, considering the oil lubricant between the teeth of the unloaded gears acting as a damper during the impacts. A layout of a gearbox with six speed ratios has been assumed, in which a dual clutch system transmits the drive torque alternatively between the various gear pairs in the odd and even branches. The results of the numerical simulations show that this kind of transmission system is characterised by hard rattling behaviour, particularly during the rapid phases of clutches engaging/disengaging and during the gears synchronisation. Some solutions to attenuate the torsional vibrations, and therefore the rattling behaviour of the unloaded gears in a DCT gearbox, can be analysed by the proposed model to determine, as example, the time duration of the gear shift phase or of the pre-selection phase to the next gear, as well as to identify the optimal lubrication conditions of the gear pairs during the gear shift transients.
8
Wu, Yi-Chang, e Che-Wei Chang. "DEVELOPMENT OF 3-SPEED REAR HUB BICYCLE TRANSMISSIONS WITH GEAR-SHIFTING MECHANISMS". Transactions of the Canadian Society for Mechanical Engineering 39, n. 3 (settembre 2015): 407–18. http://dx.doi.org/10.1139/tcsme-2015-0030.
Testo completoAbstract (sommario):
Rear hub bicycle transmissions require less maintenance and are more reliable than rear derailleurs. This study proposes a systematic design process for the conceptual design of 3-speed rear hub bicycle transmissions. By analyzing the kinematics of a basic epicyclic gear mechanism using the fundamental circuit method, the gear sequence and clutching sequence arrangements for 3-speed rear hub transmissions can be obtained. The numbers of gear-teeth for all gear elements resulting in a minimum installation space and satisfying the required speed ratio at each gear stage are determined. A gear-shifting mechanism is constructed to sequentially control the power-flow path within the epicyclic gear mechanism so as to provide three forward gears. An atlas of 3-speed rear hub bicycle transmissions is listed, where three devices are new design concepts and are suitable for further embodiment design. The results of this study will lead to the creation of new multi-speed rear hub bicycle transmissions.
9
Handschuh, R. F., D. G. Lewicki e R. B. Bossler. "Experimental Testing of Prototype Face Gears for Helicopter Transmissions". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 208, n. 2 (luglio 1994): 129–36. http://dx.doi.org/10.1243/pime_proc_1994_208_262_02.
Testo completoAbstract (sommario):
An experimental programme to test the feasibility of using face gears in a high-speed and high-power environment was conducted. Four face gear sets were tested, two sets at a time, in a closed-loop test stand at pinion rotational speeds to 19 100 r/min and to 271 kW (364 b.h.p.). The test gear sets were one-half scale of the helicopter design gear set. Testing the gears at one-eighth power, the test gear set had slightly increased bending and compressive stresses when compared to the full-scale design. The tests were performed in the NASA Lewis spiral bevel gear test facility. All four sets of gears successfully ran at 100 per cent of design torque and speed for 30 million pinion cycles, and two sets successfully ran at 200 per cent of torque for an additional 30 million pinion cycles. The results, although limited, demonstrated the feasibility of using face gears for high-speed, high-load applications.
10
Liu, Dezheng, Yan Li, Zhongren Wang, You Wang e Yu Wang. "Modeling and Analysis of Effective Case Depth on Meshing Strength of Internal Gear Transmissions". Mathematical Problems in Engineering 2018 (30 dicembre 2018): 1–12. http://dx.doi.org/10.1155/2018/5153292.
Testo completoAbstract (sommario):
The effective case depth (ECD) plays an important role in the meshing strength of internal gear transmissions. Carburizing quenching heat treatment is commonly used to enhance gear strength and wear resistance. However, the different ECDs in internal and external gears caused by heat treatment significantly affect the meshing strength, causing vibration, reducing gear service life, and hastening malfunction in internal gear transmission. In this study, we conducted an investigation of different ECDs by the heat treatment of carburized gear pairs by numerical simulation with the finite element method (FEM) and experiment tests. We analyzed three different carburized layer models, with the ECD in the internal gear being greater than, less than, and equal to the ECD in the external gear. In addition, we investigated the ability to distinguish between hardness gradients in gear teeth by dividing the carburized depth into seven layers to improve modeling accuracy. Results revealed that the meshing strength of internal gear transmission could be significantly enhanced by adopting the model with the ECD in the internal gear being less than the ECD in the external gear, and moreover, the shear stress of carburized gears initially increased and then decreased along with depth direction, and the maximum value appeared in the middle of the lower surface.
11
Hsu, C.-H., e R.-H. Huang. "Design of parallel-connected epicyclic-type automatic transmissions with two fundamental geared entities". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 222, n. 3 (1 marzo 2008): 371–81. http://dx.doi.org/10.1243/09544070jauto548.
Testo completoAbstract (sommario):
The purpose of this paper is to present a systematic methodology to simplify effectively the design of automatic transmissions by using the concepts of fundamental geared entity and basic gear ratios. An atlas of parallel-connected epicyclic-type automatic transmissions is first enumerated. Next, an effective procedure is developed to synthesize feasible clutching sequences for all the parallel-connected epicyclic gear mechanisms with two fundamental geared entities. Then, the numbers of teeth of gears in each epicyclic gear mechanism are determined by an analytical method. Finally, four alternatives for four-speed automatic transmissions are generated, and the corresponding rotating and band clutches are embodied to the epicyclic gear mechanism to obtain the atlas of four-speed automatic transmissions. The result of this paper shows that three four-speed automatic transmissions can be synthesized from the atlas of parallel-connected epicyclic gear mechanisms with two fundamental geared entities
12
Alendeev, E. M., e V. A. Kryuchkov. "VARIANTS OF TWO-COUPLE GEAR SHIFTING ORGANIZATION ON TRACTORS". Traktory i sel hozmashiny 84, n. 3 (15 marzo 2017): 10–18. http://dx.doi.org/10.17816/0321-4443-66254.
Testo completoAbstract (sommario):
In recent years, we can see trend of increasing tractor transport and operating speeds, which is also accompanied by increasing of gears number in manual transmissions. Increasing of gears number in Powershift transmissions is achieved by using in gearbox construction a few operating ranges. Every range and every gear of such gearboxes are switched by separate friction clutch that gives opportunity to organize gear shifting without power interruption in all tractor speed range. However, such technical solutions lead to appearing gear shifting, requiring of pressure control in four friction clutches at once (two-couple gear shifting): two gear clutches and two range clutches. This article is dedicated to the questions of two-couple gear shifting process organization in agricultural tractor gearboxes. These questions had required to design mathematical model of this process in Matlab Simulink software. Modelling was implemented under conditions that transmission control system and engine control system had opportunity of data exchange between themselves, which allowed to define the load torque value, acting on engine, and to control engine speed. A few variants of two-couple gear shifting up and down organization were modelled and compared in parameters of clutch wear. The modelling results show that simultaneous high gear clutch and high range clutch slipping during gear shifting gives the same oncoming clutches accelerated synchronization as during gear shifting with engine control.
13
He, Chunyan, Zaigang Chen, Wanming Zhai, Jianzheng Jiang e Kaiyun Wang. "A spatial dynamics model for heavy-haul electric locomotives considering the dynamic coupling effect of gear transmissions". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 233, n. 9 (13 gennaio 2019): 961–73. http://dx.doi.org/10.1177/0954409718823138.
Testo completoAbstract (sommario):
A locomotive is usually powered by the electromagnetic torque which is transmitted from the traction motor to the wheelset by gear transmission. In order to investigate the dynamic coupling effects from the gear transmission subsystems on the entire locomotive dynamics system, a comprehensive spatial locomotive dynamics model that considers the dynamic coupling effect of the gear transmissions is developed based on the multibody dynamics theory. In this model, the moved Marker technique is employed to calculate the dynamic mesh force of the gear pairs through which more accurate time-varying gear mesh stiffness excitations could be imported, which is the core of this dynamic model. Then, the established locomotive dynamics model is validated by comparing with the experimental test results. Finally, the dynamic effects of the gear transmissions are revealed by comparing with the results from the traditional locomotive dynamics model without considering the dynamic excitations from the gear transmissions. The results indicate that the gear transmissions have negligible effects on the vibrations of the carbody and the bogie frame, and on the lateral vibrations of the motor and the wheelset. However, the gear transmissions have significant effects on the vertical and, in particular, the longitudinal vibrations of the motor and the wheelset. Thus, it is suggested that the dynamic effects of the gear transmissions are considered in the locomotive dynamics modeling, especially when the vibrations of the motors and the wheelsets are taken into account.
14
Sosnin, A. A., N. V. Buzunov, I. D. Khlobystov e A. B. Kartashov. "Analysis of control systems for mechatronic transmission gear shift mechanisms". Trudy NAMI, n. 3 (24 settembre 2023): 71–78. http://dx.doi.org/10.51187/0135-3152-2023-3-71-78.
Testo completoAbstract (sommario):
Introduction (problem statement and relevance). Within the study, review and analysis of possible variants for gear shift control systems architecture for vehicles with mechatronic transmissions are made to detect the respective advantages and disadvantages for each scheme and to determine the most optimum solution for application within the mentioned wheeled vehicles in terms of energy consumption and performance.The purpose of the study is to determine the most optimum control system for mechatronic transmission gear shift mechanisms of electric vehicles.Methodology and research methods. This paper is based on methods of reviewing and analyzing gear shift mechanism control systems for the transmission configurations in question.Scientific novelty and results. The results of the conducted analysis showed that the most suitable variant for the gear shift process control would be the systems based on electric actuators. These control systems will allow providing the required performance when shifting gears as well as lowering total energy costs.Practical significance. The obtained conclusions can be used when designing gear shift control systems within mechatronic transmissions for vehicles propelled by electrochemical power sources.
15
Li, Xueliang, Jibin Hu e Zengxiong Peng. "Synthesis method for compact dual-clutch transmission with four DOFs gear mechanism". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, n. 11 (16 novembre 2018): 2929–38. http://dx.doi.org/10.1177/0954407018811043.
Testo completoAbstract (sommario):
The design of dual-clutch transmission with multi-degrees-of-freedom (DOFs) is a good solution to increase in number of gears and a wider range of gear ratio in the limited space and weight. This article proposes a novel synthesis method for scheme design of the dual-clutch transmission with four degrees-of-freedoms gear mechanism. First, the shift sequences considering the path of power flow and shift logics are analyzed based on the degrees-of-freedom model, abstracted from the degrees-of-freedom of the schemes. Second, the schemes of gear-pair and shaft, defined as the scheme that ignores the arrangement of synchronizers, are derived from the basic configurations, defined as the schemes of gear-pair and shaft that contains only one of each type of the variable connections, and the numbers of each type of the variable connections. Finally, multi-parameter, including synchronizers arrangement and gear ratios, is optimally designed for the results of synthesis. The seven-speed dual-clutch transmission schemes with four degrees-of-freedom and two shaft systems are taken as an example to explain this synthesis method. In addition, this article helps to obtain a deeper understanding of the systematic design of other fixed gear transmission schemes, such as automated mechanical transmission, automated mechanical transmissions with electric torque supporting, and even some novel multi-input transmissions.
16
Cristescu, Ana, Bogdan Cristescu e Laurenţia Andrei. "Designing Multispeed Gear Pitch Curves". Applied Mechanics and Materials 657 (ottobre 2014): 480–84. http://dx.doi.org/10.4028/www.scientific.net/amm.657.480.
Testo completoAbstract (sommario):
As special mechanical systems within transmissions of unconventional motions, noncircular gears still offer multiple research opportunities due to their various geometries and kinematics characteristics. Investigation on noncircular gears highlights the lack of information on gears with combination of constant and variable speed, also named multispeed gears, recommended for industrial applications that require uniform speeds for different parts of a cycle, with a smooth transition between the parts. Therefore, in this paper the design of multispeed gears pitch curves is taken into account, as the first important step in the gear design procedure. Specific original algorithms are dedicated to multispeed gear pitch curve modeling, based on the definition of gear transmission ratio variation law. The next step of the multispeed gear design, the teeth generation, accessible through solid modeling or analytical procedure, will be approached in a future study.
17
Bai, S., e J. Angeles. "The design of spherical multilobe-cam mechanisms". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, n. 2 (1 febbraio 2009): 473–82. http://dx.doi.org/10.1243/09544062jmes1154.
Testo completoAbstract (sommario):
Cam—roller mechanisms can be used in transmissions and robotic devices as an alternative to their bevel-gear counterparts. As bevel gears are used to couple shafts of intersecting axes, their cam-mechanism replacements are bound to have intersecting axes as well. This means that the contact surface of the cam must be conical, which leads to spherical cam mechanisms. Compared with gear transmissions, cam—roller mechanisms feature low friction, low backlash, and high strength. However, cam mechanisms may end up with a high pressure angle if negative action, a motion in which the cam is driven by mechanism rollers, occurs. This article reports the design of transmissions with spherical multilobe cams (MLCs), as a means to reduce the pressure angle. The kinematics of MLC, including profile generation, undercutting-avoidance, and transmission-quality evaluation, is studied here. A case study has been included, in which the synthesis of a spherical MLC transmission is undertaken as a means to improve the transmission quality of a spherical epicyclic gear train. This train was introduced with the purpose of producing a singularity-free, unlimited-workspace pitch—roll wrist.
18
Kahraman, A., H. Ligata, K. Kienzle e D. M. Zini. "A Kinematics and Power Flow Analysis Methodology for Automatic Transmission Planetary Gear Trains". Journal of Mechanical Design 126, n. 6 (1 novembre 2004): 1071–81. http://dx.doi.org/10.1115/1.1814388.
Testo completoAbstract (sommario):
A generalized formulation for analyzing speeds and forces of the gear components of planetary automatic transmissions is proposed. The formulation is capable of analyzing any typical one-degree-of-freedom automatic transmission gear train containing any number of simple, compound or complex-compound planetary gear sets. The formulation consists of three components: a kinematic analysis formulation to compute rotational speeds of gears and carriers, a gear ratio and kinematic configuration search algorithm, and a power flow analysis formulation. The kinematics component computes rotational speeds of gears and carriers. Given the type and number of planetary gear sets, the search algorithm determines all possible kinematic configurations and gear tooth count combinations that result in a required set of gear ratios while eliminating all kinematic redundancies and unfavorable clutching sequences. The third component, the power-flow analysis formulation, performs a complete static force (power-flow) analysis to determine all gear and bearing forces and moments, and clutch and connection torque values. A five-speed transmission example is considered to highlight the capabilities of the proposed formulation.
19
Zaman, Muhammad, Muhammad Atif e Mudassar Naseer. "Formal Verification of Twin Clutch Gear Control". VAWKUM Transactions on Computer Sciences 10, n. 2 (30 dicembre 2022): 24–33. http://dx.doi.org/10.21015/vtcs.v10i2.1273.
Testo completoAbstract (sommario):
Twin clutch model enables the power-shifts as conventional planetary automatic transmission and eradicates the disadvantages of single clutch transmission. The automatic control of the dual clutches is a synchronization problem. Particularly, to control the clutching component that engages torque when running in one direction of revolution and disengages when running in the other direction, which exchange the torque smoothly during torque phase of the gear-shifts on planetary-type automatic transmissions, seemed for quite a while hard to compensate through clutch control. Another problem is to skip gears during multiple gearshifts. However, the twin clutch gear control described in ["M Goetz, M C Levesley and D A Crolla. Dynamics and control of gearshifts on twin clutch transmissions, Proceedings of the Institution of Mechanical Engineers, Journal of Automobile Engineering 2005"], a significant improvement in twin clutch gear control system is discussed. We formally specify the algorithm for the twin clutch gear control system and verify it using the model-checking. Formal methods have a high potential to measure correctness of communicating protocols. We use UPPAAL for formal specification and verification. Our results show that the twin clutch gear control model partially fulfills its functional requirements
20
Idelevich, A. Ya. "Measuring moving gears in multilink gear transmissions". Measurement Techniques 35, n. 8 (agosto 1992): 923–25. http://dx.doi.org/10.1007/bf00977433.
Testo completo
21
Lebedev, S. Yu, e V. N. Syzrantsev. "Calculating the probability of the failure-free operation of spur gear transmissions". Diagnostics, Resource and Mechanics of materials and structures, n. 3 (giugno 2022): 13–24. http://dx.doi.org/10.17804/2410-9908.2022.3.013-024.
Testo completoAbstract (sommario):
The article presents an improved method for calculating the probability of failure-free operation of case-hardened spur gear transmissions. The existing methods for calculating the probability of failure-free operation of gear transmissions are analyzed. The failure tree for a case-hardened spur gear transmission is presented. The probability of failure-free operation of case-hardened cylindrical gear transmissions is presented as the product of the probabilities of failure-free operation of the gear and the wheel according to the following criteria (failure types): contact endurance (pitting), bending endurance (tooth breakage), and tooth interior fatigue fracture (deep contact chipping). An algorithm has been developed for calculating the probability of failure-free operation of case-hardened spur gear transmissions. To restore the torque distribution density function in the proposed method, nonparametric statistics methods are implemented. In the calculation of contact stresses, the skew angle is taken into account, which is the sum of two angles: the skew angle due to deformations of the transmission elements and the housing; the total angle of technological misalignment of wheel tooth surfaces, caused by errors in the manufacture of the teeth and mounting errors during the assembly of the transmission. An example of a test calculation of the probability of failure-free operation of a case-hardened spur gear transmission according to the presented method is given. Based on the work performed, conclusions are formulated.
22
Rackov, Milan, Siniša Kuzmanović, Ivan Knežević, Maja Čavić e Marko Penčić. "Analysis of Conceptual Solutions of Universal Helical Geared Reducers". International Journal of Engineering and Management Sciences 5, n. 2 (15 aprile 2020): 64–72. http://dx.doi.org/10.21791/ijems.2020.2.8.
Testo completoAbstract (sommario):
Geared reducers are mechanisms designed to reduce the number of revolutions using geared elements and nowadays they present one of the most commonly used types of mechanical transmissions in mechanical engineering. Due to the different shapes of geared elements, there are different types of geared transmissions: helical, bevel, worm, special and combined transmissions. This paper analyses only helical geared transmissions, since there is a great extent of whole this matter. Helical transmissions are analysed only with external helical gearing, since internal geared pairs represent a special and very large group of gears. Within the external helical geared transmissions, only torque transmissions are analysed, while the transmissions of motion are not analysed and they represent another large group of transmissions. Only universal gear reducers with axial, or almost-axial, parallel shafts are considered (two-stage and three-stage transmissions). Although, single-stage gear reducer produced with parallel shafts are not considered by the paper in order to reduce the area of researching. Gear reducers are most commonly delivered to customer with electric motor, known as motor geared reducer, and they are studied here extensively. Gear reducer can be also delivered without motor, only with input shaft. The basic aim of this paper is to present all characteristics and specificities of motor geared reducer in one place.
23
Sharipov, V. M., G. O. Kotiev, Yu S. Shchetinin, M. V. Vyaznikov, S. V. Gaev e M. G. Rozenoer. "On the selection of parameters of double-flow hydromechanical transmission for industrial and forestry tractors". Traktory i sel hozmashiny 83, n. 3 (15 marzo 2016): 8–14. http://dx.doi.org/10.17816/0321-4443-66117.
Testo completoAbstract (sommario):
Double-flow hydromechanical transmissions are widely used in industrial and forestry tractors. The main advantage of such transmission is the higher value of the maximum efficiency coefficient in comparison with the single-flow one. The article presents a method of selection of parameters of such transmissions for industrial and forestry tractors. In this case, it considers the hydromechanical transmission with a differential unit at the input and at the output. Three-link differential devices with mixed type of gear engagement are used as the differential unit. All of the twelve possible schemes of double-flow hydrodynamical transmissions are considered. It is shown that double-flow hydrodynamical transmission has an operation mode when the torque converter turbine is rotating counter to the rotation of pump wheel. This factor is taken into account during the selection of parameters of double-flow hydrodynamical transmission. The article describes the method of construction of external characteristic of the transmission and matching of its load characteristic with the full-load curve of diesel engine. The matching is performed by three ways: the selection of required value of active diameter of torque converter; the selection of reduction ratio of matching gear; the selection of characteristic of planetary gear set. It is found that for the most common scheme of double-flow hydromechanical transmission when the characteristic of planetary gear set is reduced, its maximum efficiency coefficient is increased, the active diameter of torque converter is reduced and the relative rotation frequency of satellite gears of three-link differential device is increased. In this case, the rotation frequency of satellite gears limits the minimum value of characteristic of planetary gear set. Increasing of characteristic of planetary gear set leads to the reducing of transparency of the hydromechanical transmission and to increasing of its transformation ratio. It is shown that the double-flow hydromechanical transmission allows to utilize more fully the converting properties of engine in comparison with the single-flow one; it allows to change the torque value if external engine load is changing, that is very important for industrial and forestry tractors.
24
Molyneux, W. G. "The internal bevel gear and its applications". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 211, n. 1 (1 gennaio 1997): 39–61. http://dx.doi.org/10.1243/0954410971532488.
Testo completoAbstract (sommario):
Information on bevel gears and their applications is comprehensive where external bevel gears are concerned but proves to be more scarce when related to internal bevel gears, despite the fact that there are isolated practical examples of the use of such gears that have demonstrated their effectiveness in demanding transmission situations. In what follows a unique family of transmissions is examined, based solely on a particular layout of internal and external bevel gear combinations, that aims to demonstrate the wide ranging, largely unexploited, potential of transmission systems of this kind.
25
Sierykov, Volodymyr. "ANALYSIS OF RESEARCH ON PLANETARY GEARBOXES OF ARMORED VEHICLES (REVIEW ARTICLE)". Bulletin of the National Technical University «KhPI» Series: Engineering and CAD, n. 2 (18 dicembre 2023): 57–68. http://dx.doi.org/10.20998/2079-0775.2023.2.09.
Testo completoAbstract (sommario):
The work is devoted to the review of modern trends in the research and use of planetary gearboxes of armored vehicles. An analysis of the areas of application of mechanical transmissions was carried out. The advantages and disadvantages of using gear gearboxes as part of mechanical transmissions are described. The design features of the use of gears in transmissions are considered. The requirements for gear gearboxes as part of transmissions are defined. The advantages and disadvantages of using planetary gearboxes and their areas of use are analyzed. The classification of mechanical adjustable gears according to general features, as well as individual ones, is considered. An overview of the fulfillment of the conditions for increasing reliability was carried out, taking into account the design features of stepped gearboxes, which are divided into three groups: simple gearboxes (with fixed shaft axes); planetary gearboxes (with movable shaft axes); combined (combination of a simple and planetary gearbox in one unit). A brief review of modern approaches to planetary gear box modeling, taking into account inertial, elastic, dissipative, transformer and frictional properties, taking into account other characteristic features of the planetary series, is carried out. An analysis of known ways of solving problems of such modeling was carried out. Modern methods of calculating the strength of planetary gearboxes, including those with partial destruction, and corresponding software complexes are analyzed. The need for the development of more advanced mathematical models that adequately describe the stress-strain state in gear engagements has been identified. Keywords: design, planetary gearboxes, mechanical transmission, influence of operating factors, diagnostic parameters, synthesis of kinematic schemes
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Wang, Haiwei, Cheng Ji, Fengxia Lu, Cheng Wang e Xueyan Sun. "A Generalized Dynamic Model and Coupling Meshing Force Analysis for Planetary Gear Set Transmissions". Applied Sciences 12, n. 12 (20 giugno 2022): 6279. http://dx.doi.org/10.3390/app12126279.
Testo completoAbstract (sommario):
The dynamics analysis of a planetary gear set transmissions requires the creation of completely different models for different gears, which is very tedious. In this paper, a generalized dynamics modeling process is proposed for a three planetary gear set transmissions, and a generalized dynamic model for multiple gears is established by using the lumped mass method. The analysis of meshing force characteristics is carried out for the second gear position, and the meshing frequency coupling phenomenon between the meshing forces of the three planetary gear sets is investigated. The results show that, for the current gear set of meshing force, the meshing frequency components of other gear sets only appear in a part of the speed, and with the increase in speed, certain low-frequency components of other sets that exist at low speed will decrease or even disappear, and the coupling relationship between the meshing forces of different planetary gear sets is not symmetrical.
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Voropay, Alexey, Olexandr Koriak, Dmytro Bogdan e Eduard Neskreba. "Optimization of key gear parameters to reduce weight". Automobile transport, n. 52 (26 luglio 2023): 32–40. http://dx.doi.org/10.30977/at.2219-8342.2023.52.0.04.
Testo completoAbstract (sommario):
Problem. The problems of designing, and especially improving, mechanical gears are of key importance in modern mechanical engineering and automotive transport. Gear transmissions are quite widespread relative to other mechanical transmissions because they have a number of crucial advantages. Gear transmissions are widely used in a variety of drives for vehicle components and assemblies, with modern development trends aimed at reducing their weight and size. As the size of the transmission decreases, the dimensions of other parts and assemblies also decrease, and, accordingly, their cost. Therefore, research related to the study of the interdependence of the main parameters of gears for the purpose of their further optimization does not lose its relevance. Goal. The main purpose of this work is to study the dependence of the mass and dimensions of the gears under study on their main parameters. Knowing the influence of various characteristics on the mass, it is possible to provide recommendations for the design of gears to achieve their optimal (smallest) dimensions, which leads to a number of significant advantages. Methodology. First of all, a rather detailed analysis of the scientific literature is performed in order to identify the main statements regarding the influence of certain parameters on the mass and dimensions of the designed gear. The very dependencies of the gear mass on its various characteristics are found by applying a numerical method that is entirely based on the known design dependencies for the design calculation of gears. Also, to compare the results obtained analytically, the method of calculating the mass and dimensions by creating 3D models of gears in the "Autodesk Inventor" environment is used in the work. Results. Based on the results obtained, it can be noted that, ceteris paribus, including gear load, the weight is almost independent of the module and the relative width ratio. At the same time, in some cases, a particular standard value can significantly affect the weight of the gear, i.e., by selecting specific values, it is possible to reduce the weight of the gear by about 15-25%. Originality. Useful results were obtained using a relatively affordable method. The research was conducted both analytically and with the use of modern computer-aided design systems. Practical value. The proposed recommendations for the rational choice of some characteristics of gears will reduce the weight and dimensions of the mechanical drive.
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Hsieh, Long Chang, e Hsiu Chen Tang. "The Kinematic Design of Three-Speed Automatic Transmission for Electric Motorcycle". Applied Mechanics and Materials 284-287 (gennaio 2013): 979–82. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.979.
Testo completoAbstract (sommario):
Motorcycle is invented so far more than 100 years. Because of having the advantages of light weight, cheap and fast-moving, motorcycle becomes the most popular traffic vehicle. Traditionally, the power systems of motorcycles are internal combustion engines. Recently, due to the reason of energy-saving, and carbon reduction, the engine in motorcycle is substituted by electric motor. Hence, due to the reason of pollution-free, electric motorcycle become more and more popular in city traffic. Planetary gear trains can be used as the transmission systems for electric motorcycles. The purpose of this work is to do the kinematic design of three-speed planetary gear type automatic transmissions for electric motorcycles. First, according to the train value equation of planetary gear train, The reduction ratio equations of planetary gear type automatic transmissions can be derived. Then , based on these reduction ratio equations, the kinematic design of three-speed planetary gear type automatic transmission is accomplished. Based on the proposed methodology, all three-speed planetary gear type automatic transmissions can be synthesized.
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Höhn, Bernd Robert. "Future Transmissions for Wind Turbines". Applied Mechanics and Materials 86 (agosto 2011): 18–25. http://dx.doi.org/10.4028/www.scientific.net/amm.86.18.
Testo completoAbstract (sommario):
Most transmissions for wind turbines are set up by multiple consecutively arranged planetary gear sets and/or normal gear sets. Therefore these transmissions have a constant ratio. In order to feed the electricity produced by the wind turbines into the grid, an electric conversion to a constant frequency of 50 Hz is necessary. FZG developed a new concept for transmissions of wind turbines based on a planetary gear. By superposition of a small electric engine the transmission ratio is continuously variable. This makes an electric conversion unnecessary and thereby increases the efficiency of the wind turbine.
30
Dong, Peng, Yongfei Wang, Shengdun Zhao, Zhuoneng Gao, Yongqiang Zhao, Yangfeng Cao e Peng Zhang. "Design and experimental study of novel multi-stage gearbox". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 235, n. 1 (6 agosto 2020): 105–13. http://dx.doi.org/10.1177/0954407020945823.
Testo completoAbstract (sommario):
Automatic transmission has been widely used in the automotive industry, and novel automatic transmissions with simple structure and reliable operation are a research hotspot. This paper proposes an automatic transmission with multi-stage gears to simplify its working process. The automatic transmission comprises a case and a driving transmission shaft and driven shaft which are mounted on the case. The transmission gear pairs are superimposed on the driving and driven shafts similar to a tower. The gear pairs on the driving and driven shafts are always engaged. All the driving gears are connected to the driven shaft via a flat key, and the driven gear and the driven shaft are connected by a join key, which is used to connect or disconnect the gear and the driven shaft, and are controlled by a hydraulic shifting mechanism and have been designed in detail. Numerical simulation is adopted to verify the strength of the core components. In addition, the transmission performance of the gearbox is experimentally tested. The results indicate that the novel gearbox can achieve variable speed and work smoothly. The gearbox has a novel structure, the driving and driven shafts are simple and installed friendly, and the transmission gear meshes are reliable.
31
Abadjiev, Valentin, e Emilia Abadjieva. "One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets With Face Mating Gears. Part 1: Basic Theoretical and Cad Experience". Journal of Theoretical and Applied Mechanics 46, n. 2 (1 giugno 2016): 3–26. http://dx.doi.org/10.1515/jtam-2016-0007.
Testo completoAbstract (sommario):
Abstract Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid and Helicon gear drives. The classical gear drives of this type are the Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion possesses threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three types transmis- sions with face mating gears and a conic pinion are titled Spiroid and all three types transmissions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in this study. The presented research shows that the synthesis is realized by application of two mathematical models: pitch contact point and mesh region models. Two approaches for synthesis of the gear drives in accordance with Olivier’s principles are illustrated. The algorithms and computer programs for optimization synthesis and design of the studied hyperboloid gear drives are presented.
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Abadjiev, Valentin, e Emilia Abadjieva. "Hyperboloid gear transmissions: innovations, experimental and manufacture realization". MATEC Web of Conferences 287 (2019): 04003. http://dx.doi.org/10.1051/matecconf/201928704003.
Testo completoAbstract (sommario):
This work is a review of researches carried out by the authors on prototyping processes and testing of hyperboloid gears. These activities are preceded by modeling for synthesis and design of these gear sets. It contains also a description of the innovative and inventive activities of the authors over the years. The twenty-five years period of studying hyperboloid gear mechanisms with an exact linear contact between the active tooth surfaces is entirely subordinated to the transfer of the obtained scientific results into scientifically applied and applied ones, in order to create adequate innovative products. The time interval of the researches, done from 1980 to 1990, is divided into two parts: - till 1985, the actions are oriented into transforming a part of the obtained scientific - applied results into technological innovations in the field of high-reduction gear mechanisms; - the period 1985 -1990 is identified with attempts to implement these gear transmissions into various technological devices and transport machines. From a practical view point, the 1980-1990 interval covers all activities for elaboration of functional models of reductors and technological models of high-reduction gears of type Helicon. The time period after 1990 is characterized by the elaboration of three types of Helicon reductors.
33
BOSTAN, ION, VALERIU DULGHERU e VIOREL BOSTAN. ""Analytic description of teeth profile of gears with rollers ab and justification of precessional gear parameters selection a"". Journal of Engineering Sciences and Innovation 5, n. 1 (3 febbraio 2020): 1–8. http://dx.doi.org/10.56958/jesi.2020.5.1.1.
Testo completoAbstract (sommario):
The engineering complex study of the triad “gear-technology-transmission” has permitted to elaborate a new type of mechanical transmission – planetary precessional transmissions with multicouple gear. In this paper, the authors present the mathematic model of the multicouple gear. A computer program for doing this it is also elaborated. It is shown the calculus modalities and some teeth profile diagrams.
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Abadjiev, Valentin, e Emilia Abadjieva. "One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets with Face Mating Gears. Part 2: Review of Practical Realization". Journal of Theoretical and Applied Mechanics 46, n. 3 (1 settembre 2016): 3–16. http://dx.doi.org/10.1515/jtam-2016-0013.
Testo completoAbstract (sommario):
Abstract Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid1 and Helicon gear drives. The classical gear drives of this type are Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion has threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three type transmissions with face mating gears and a conic pinion are titled Spiroid and all three type trans- missions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in Part 1: Basic theoretical and CAD experience of this study. The second part of this article is a brief overview of the innovations and inventions created in this field at the Institute of Mechanics – Bulgarian Academy of Sciences in the last three decades. This study is also dedicated on elaboration of the specialized face gear sets for implementation into bio-robot hand. It is based on the application of 3D software technology, using 3D print for the realization of the physical models of the gear drives.
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Protasov, Roman, Ľuboš Magdolen, Jan Danko, Olena Lanets e Borys Vorontsov. "ANALYSIS OF THE INFLUENCE OF THE DISPLACEMENT OF THE GEAR RACK PROFILE OF THE PAIR EVOLUTION GEARING ON THE QUALITY INDICATORS OF THE TRANSMISSION". Ukrainian Journal of Mechanical Engineering and Materials Science 9, n. 2 (2023): 66–74. http://dx.doi.org/10.23939/ujmems2023.02.066.
Testo completoAbstract (sommario):
The article is devoted to the study of the influence of the modification of the paired evolute gearing with convex-concave contact on the quality indicators of transmission, namely, the contact pressure and the speed of slippage in the engagement. Previous studies of evolute gears showed the presence of characteristic zones on the side surface of the tooth, which have worse values of quality indicators than in similar involute gear. One of the ways to remove these zones or to reduce their impact on the load capacity of the transmission is to modify the tooth profile, which will be implemented by shifting the profile of the processing gear rack. A displacement factor is added to the equation of the rail profile curve, which has the same value for the gear and wheel teeth, but the opposite sign. On the basis of the developed equation, the side profiles of the teeth of the gear and the wheel were constructed. Several values of the rack displacement coefficient with a positive and negative sign for the gear teeth are considered. The results of the research allow us to evaluate the influence of the amount and direction of the rail displacement on the curvature of the tooth profiles, the contact pressure in engagement along the height of the tooth, and the relative and absolute speed of sliding. The modifications of the profile of the processing toothed rack proposed in this work will expand the existence of paired evolute gears with a different set of quality indicators. This will make it possible to design gears with rational values of contact pressures and slip speeds when they are used in heavily loaded transmissions created for specific operating conditions. Gears with relatively high slip speeds can be used in road and construction equipment transmissions, which are characterized by low shaft rotation frequency, in which the speed of slip between the teeth does not have a significant effect on the life or efficiency of the transmission. Otherwise, gears with relatively low slip speeds are very relevant when they are implemented in the transmission of modern and promising vehicles with a hybrid or fully electric power unit, especially in the case of passenger cars with high-speed electric motors.
36
Hsu, C.-H., e J.-J. Hsu. "Epicyclic gear trains for automotive automatic transmissions". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 214, n. 5 (1 maggio 2000): 523–32. http://dx.doi.org/10.1243/0954407001527817.
Testo completoAbstract (sommario):
Epicyclic gear trains, which contain at least four coaxial links, are widely used in automatic transmissions. This paper presents a systematic methodology for the synthesis of epicyclic gear trains for automotive automatic transmissions. The graph representation of epicyclic gear trains is applied to develop an approach for the structural synthesis of the graphs of admissible epicyclic gear trains. Next, for each admissible graph the adjacency matrix of an epicyclic gear train is defined to develop an algorithm for the configuration synthesis of epicyclic gear trains. Using the proposed algorithm, all possible epicyclic gear trains for automotive automatic transmissions are systematically synthesized. In this paper, admissible epicyclic gear trains with up to ten links have been successfully synthesized. The results of work will lead to the creation of new multispeed automotive automatic transmissions.
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Gong, Fei, Rupeng Zhu, Pingjun Li e Guanghu Jin. "Analysis of Load-Sharing and Contact Characteristics of the Concentric Face Gear Split-Torque Transmission System with Elastic Supports". Applied Sciences 12, n. 10 (12 maggio 2022): 4894. http://dx.doi.org/10.3390/app12104894.
Testo completoAbstract (sommario):
The concentric face gear split-torque transmission system (CFGSTTS) is a new form of drive that is primarily used in helicopter transmission systems. Its load-sharing performance among different branches and tooth contact characteristics have a great impact on the service life of helicopter transmissions. It contains ten meshing pairs, the load distribution is complicated, and the tooth contact areas are difficult to determine. Therefore, based on the multi-point constraint method and nonconforming grid, a quasi-static analysis model of the CFGSTTS coupled with flexible supports was established and the load-sharing performance and contact characteristics were studied. The model considered the support stiffness, backlash, installation error, and web structure of the upper face gear, which could comprehensively reflect the meshing state of the system. The load-sharing coefficient curves, tooth contact area diagram, and meshing force were obtained. The results indicated that (1) a larger idler support stiffness and a smaller input gear support stiffness could achieve better load equalization performance; (2) better load equalization between idler gears could be acquired with a lower face gear support stiffness factor of approximately 0.9; (3) increasing the axial mounting error caused the contact area to shift to the top and inner end of the face gear tooth, which was detrimental to the transmission; and (4) adjusting the backlash of the idler gears, input gears, and tail gear had little influence on the load balance and contact.
38
Liu, Yanfang, Junbin Lai, Peng Dong e Xiangyang Xu. "Dynamic Analysis of Helical Planetary Gear Sets under Combined Force and Moment Loading". Shock and Vibration 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/4635204.
Testo completoAbstract (sommario):
The dynamic behavior of a single-stage planetary gear set with helical gears of multishaft automotive automatic transmissions has been studied, in which one component of the planetary gear set is imposed by additional external vertical and axial loading from countershaft gear pair in addition to the moment. Under these combined loading conditions, the contributions of the deflections of the ring gear and the carrier cannot be neglected. A three-dimensional nonlinear time-variant dynamic model considering not only the transverse, torsional, axial, and rotational motions of the gears but also the elasticity of the mounted shafts has been developed by combining the lumped parameter method with finite element method. The natural modes and the forced vibration responses due to static transmission errors have been obtained. The proposed dynamic model is employed to describe the effects of the combined external loading condition and positioning on the dynamic behavior of a four-planet system.
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Vinogradov, B. V., D. O. Fedin, V. I. Samusia e D. L. Kolosov. "Dynamic loads in self-aligning gear transmissions of heavy loaded machines". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n. 1 (2021): 84–90. http://dx.doi.org/10.33271/nvngu/2021-1/084.
Testo completoAbstract (sommario):
Purpose. Development of a mathematical model of a heavy loaded gear transmission with a self-aligning drive gear; evaluation of the dynamic load on the gear transmission in the gear alignment process. Methodology. The calculation schematic and equations of the relative motion of the self-aligning drive gear are formed using the methods of rigid body dynamics. Analytical expressions for the gear self-alignment time, collision velocity during the alignment and dynamic load factor are obtained by integrating an ordinary differential equation. Methods of the linear theory for oscillations are used to determine the dynamic factor. Findings. The article investigates the state-of-art design and mathematical models of the self-aligning gear. An equation for the relative motion of the moving part of the gear has been formed using the methods of rigid body dynamics. It is shown that by using the proposed hypotheses, the movement of the gear can be reduced to rotation about the instantaneous axis. The influence of geometric and dynamic parameters of the ball mill drive on dynamic loads in the open gear transmission is investigated. The gear alignment speed dependences on the tooth mesh misalignment angle in the gear transmission and the inertial parameters of the gear have been obtained. The obtained dependencies were used to calculate the time and speed of the gear alignment in the open gear transmission of the ball mill 5.5 6.5 (central discharge ball mill). It is shown that in the real range of mesh misalignment angles and gear parameters, the time of the gear alignment is several orders of magnitude less than the time of teeth re-engagement. In the presence of the variable component of the mesh misalignment angle, the gear will constantly make a relative motion with strikes; depending on the current value of the mesh misalignment angle, the dynamic load on the gear transmission can be significant. It is shown that when assessing the efficacy of self-aligning gears, it is necessary to take into account a possible increase in dynamic loads. The dynamic factor and the load factor are calculated for the nominal value of the mesh misalignment angle in the open gear transmission of 5.5 6.5 ball mills. Originality. A mathematical model of the dynamics of a self-aligning gear transmission in heavy duty machine drives has been developed. A quantitative assessment of internal dynamic load factor in an open gear transmission of 5.5 6.5 ball mills has been carried out. Practical value. A method for determining the dynamic component of the load on a gear transmission containing a self-aligning drive gear has been developed.
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Abdi Nugraha, I. M. Tata, I. W. Arta Wijaya e I. N. Budiastra. "ANALISIS PERBANDINGAN DAYA OUTPUT LISTRIK ANTARA PENGGUNAAN TRANSMISI GEAR DAN PULLEY PADA PROTOTYPE (PLTPH) MENGGUNAKAN TURBIN TURGO". Jurnal SPEKTRUM 10, n. 4 (31 dicembre 2023): 1. http://dx.doi.org/10.24843/spektrum.2023.v10.i04.p1.
Testo completoAbstract (sommario):
Picohydro Power Plant is one of the environmentally friendly generators that can meet the electricity needs in the vicinity, one of which is in the Kanto Lampo Waterfall Tourism area. The planning of this PLTPH prototype is carried out to meet the lighting needs in the waterfall area. This PLTPH prototype plan uses a turgo turbine and there are two transmissions that can be used, namely, gear and pulley. This study will make a comparison between gear and pulley transmissions with the direct measurement method on the prototype and aims to determine the transmission that can get the best results on the PLTPH prototype. The ratio variations used on gears and pulleys are 4:1, 4:1.3 and 4:2. The PLTPH prototype using a turgo turbine obtained the highest results at a gear ratio of 4:1 with an output power of 48.70 Watt and the resulting torque of 0.613 Nm, while the lowest results were obtained at a pulley ratio of 4:2 with an output power of 10.83 Watt and the resulting torque is 0.147 Nm.
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Baek, Seung-Min, Seung-Yun Baek, Hyeon-Ho Jeon, Wan-Soo Kim, Yeon-Soo Kim, Nam-Hyeok Kim, Taeyong Sim, Hyunggun Kim e Yong-Joo Kim. "Improvement of Gear Durability for an 86 kW Class Agricultural Tractor Transmission by Material Selection". Agriculture 12, n. 2 (18 gennaio 2022): 123. http://dx.doi.org/10.3390/agriculture12020123.
Testo completoAbstract (sommario):
This study was conducted to ensure gear durability and design optimal transmission of agricultural tractors. A field test was conducted using an 86 kW agricultural tractor for plow and rotary tillage, which are typical agricultural operations. The field test was completed after about 107 h due to transmission noise and operational problems. As a result of disassembling the transmission, it was found that the range shift A and B gears were damaged. In the case of the range shift A gear, it was judged that plastic deformation occurred due to low contact stress, and the bending stress was low, therefore gear tooth breakage occurred in the range shift B gear. In order to ensure the durability of the transmission, four materials of alloy steel for machine structural use, such as SCr420, SNCM220, SCM822, and SNC815, were selected, and the safety factor and service life according to the gear materials were compared using simulation software. As a result of simulation analysis, SCM822 satisfied the target life value and was selected as a material for change. The damaged range shift A and B gears were changed to SCM822, and an axle dynamometer test was performed for the verification of the modified transmission. After conducting the axle dynamometer test, the transmission was disassembled, and it was confirmed that the range shift A and B gears were in normal condition. Therefore, it was considered that the durability of the transmission was ensured by satisfying the target life requirements of the gears. In the future, the transmission simulation model for 86 kW class agricultural tractor is expected to be utilized for the development of tractor transmissions, cost reduction, and optimal design.
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Siddiqui, Maimuna. "MODELLING AND 3D-PRINTING OF BEVEL GEAR". INTERANTIONAL JOURNAL OF SCIENTIFIC RESEARCH IN ENGINEERING AND MANAGEMENT 08, n. 05 (6 maggio 2024): 1–5. http://dx.doi.org/10.55041/ijsrem33290.
Testo completoAbstract (sommario):
Bevel gear have teeth cut on conical blanks. The gear pair is used to connect non-parallel intersecting shafts for motor transmissions, differential drives and mechanical instruments. Bevel gears are used for transmission of power between axles in rear wheel of vehicle will be modelled by using solid works. Shaping, Casting and Grinding are the traditional methods of manufacturing of bevel gear which are time consuming, and increased in production cost. To overcome this, new method such as rapid prototyping method of manufacturing is used which offers the potential for faster and more cost-effective manufacturing with ability to customize the design and improve performance. In this project, the Bevel Gear is designed using solid works by ensuring that the gear's dimensions and tolerances are appropriate for the 3D printing process being used and then the Bevel Gear is printed using the 3D- Printer. Keywords: Bevel Gear, 3D Printing,Rapid Prototyping, Design
43
Vinogradov, V. M., e A. A. Cherepakhin. "Parametric optimization of gear cutting operations". Izvestiya MGTU MAMI 7, n. 1-2 (10 marzo 2013): 22–30. http://dx.doi.org/10.17816/2074-0530-67979.
Testo completoAbstract (sommario):
Matters of parametric optimization of manufacturing processes of medium pitch gears for transmissions, vehicle engines and drives of machine tools are illustrated in the paper. The mathematical model of gear cutting operation and the algorithm of parametric optimization of the machining process of a ring gear are developed by the authors. There are presented the ways of improving of manufacturing methods for gear cutting process.
44
Zeng, Qing Dun, e Feng Zhe Tan. "Finite Element Analysis of Gear Contact on Two-Speed Transmission in Electric Cars". Applied Mechanics and Materials 341-342 (luglio 2013): 443–46. http://dx.doi.org/10.4028/www.scientific.net/amm.341-342.443.
Testo completoAbstract (sommario):
The main content of gear design is the strength design, and the contact strength design of gears is the main heart of the strength design, because the stress and deformation of gears directly affect their safety and service life and concern whether vehicle transmissions work smoothly. Therefore it is necessary to perform a finite element analysis for the gear contact in transmission. Based on the contact characteristic of helical gears, a three-dimensional solid model was established by using the software Pro/E, and the contact stress analysis of gears was carried out by the software ANSYS Workbench. The stress and strain distribution contours of helical gears were obtained, and then the check of shtrength and rigidity was performed. Thus, it is convenient for designers both to test the strength of gears and to modify the size of gears.
45
Liu, Shiqi. "Common transmission theory and wide application". Theoretical and Natural Science 30, n. 1 (15 gennaio 2024): 165–71. http://dx.doi.org/10.54254/2753-8818/30/20241095.
Testo completoAbstract (sommario):
Gear and belts/chains are the most common solution for modern mechanical devices. The allowable stress and gear ratio are two of the main factors that decide the performance of the ear section for transmission. The allowable stress can be calculated by bending stress and contact stress from design criteria. The performance of the belt solution is decided by the belt/chain material, center distance and the belt length. The allowable strength of the belt/chain solution is strongly related to the materials selected. With the current study of belts and gears, the related factors could be calculated to design the optimum shape and material. Dual clutch transmission (DCT) and continuously variable transmission (CVT) are two widely applied transmissions with gear and belt/chain solutions that are introduced in the research. The advantages of DCT could be the reliability and high transmission efficiency of the gear solution and the space and energy efficiency of belt/chain structure advantages of the CVT. Both DCT and CVT could be applied in different conditions to maximize the specific performance.
46
Sharipov, V. M., Yu S. Shchetinin e M. I. Dmitriev. "Kinematic analysis of double-flow hydromechanical transmissions". Traktory i sel hozmashiny 83, n. 12 (15 dicembre 2016): 10–15. http://dx.doi.org/10.17816/0321-4443-66243.
Testo completoAbstract (sommario):
Double-flow hydromechanical transmissions become more and more widely used in designs of modern tractors and automobiles. Double-flow hydromechanical transmission includes a torque converter or a complex hydrodynamic transmission and a differential unit made in form of three-link differential device. The article discusses all of the 12 possible schemes of double-flow hydromechanical transmissions with a differential unit at the input and at the output with mixed type of gear engagement, and also presents the results of their kinematic analysis. For all of the 12 possible schemes, the expressions are given for determining the angular velocity of links of three-link differential device, depending on the gear ratio of double-flow hydromechanical transmission and the characteristics of planetary gear set. The calculation results with the use of these expressions are presented as curves. It is found that in 4 of the 12 schemes, it is very likely that the angular velocity of either sun gear or satellites will exceed the limits admissible for rolling bearings. There is no such problem for other 4 schemes. The other schemes are applicable to a limited range of characteristics of the planetary gear set. It is found that for 6 schemes there is a possibility that when transmission is functioning in the range of variation of gear ratio from infinity to 1, the torque converter can be operated in modes not typical for its normal operation (the turbine wheel rotates faster than the pump wheel; the turbine wheel rotates counter to the rotation of pump wheel; pump wheel rotates in the opposite direction in relation to the reactor). The triggering conditions of such modes are established and variation limits of gear ratio of torque converter are determined for them.
47
Knežević, Rade, Branko Đedović e Marko Paić. "On stochastic processes in the dynamics of planetary transmissions". Tehnika 78, n. 2 (2023): 177–83. http://dx.doi.org/10.5937/tehnika2302177k.
Testo completoAbstract (sommario):
In addition to the theoretical analysis of the nonlinear dynamics of dissipative mechanical systems with the possibility of stochastic and chaotic processes, the paper also includes a numerical experimental example of a planetary transmission. The most common non-linear effects of operation and their influence on the behavior of the planetary gear as a system were analyzed. A simplified model of planetary gears as dissipative dynamic systems whose operation is a complex dynamic process with different effects was considered. These operating effects can appear in many different ways and can be the cause of stochasticity in the operation of the planetary gear. A numerical analysis of planetary gear lubrication was made, as one of the effects of stochasticity, where turbulent damping occurs. The turbulent damping force, due to oil splashing, is taken to be proportional to the second power of the angular velocity of the sun gear. Based on the experiment, it is concluded that the phase space in this system is not preserved and the system is dissipative because the trajectories spiral down into a certain singularity.
48
Davies, D. P., e B. C. Gittos. "Gear Steels for Future Helicopter Transmissions". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 203, n. 2 (luglio 1989): 113–21. http://dx.doi.org/10.1243/pime_proc_1989_203_062_01.
Testo completoAbstract (sommario):
In order to reduce weight, improve reliability and increase safety, significant changes in the design of future helicopter transmissions are envisaged. Such designs are likely to place new demands on conventional steels which will eventually result in the capability of the gear steels themselves to become the limiting factor, restricting any further opportunities for transmission design and development.
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Li, Zhibin, Sanmin Wang, Fei Li, Qi'an Peng e Jianfeng Li. "Research on matching conditions of coaxial six-branch split-torsion herringbone gear transmission system". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 39, n. 2 (aprile 2021): 341–49. http://dx.doi.org/10.1051/jnwpu/20213920341.
Testo completoAbstract (sommario):
Compared with traditional gear transmission, the multi-branch split-torsion gear transmission system has the advantages of large transmission power, small size and high reliability, so it is more and more used in high-speed heavy load occasions such as ships and aircraft. Since the transmission system of multi-branch split torsional gears belongs to over-constrained configuration, it is necessary to meet strict tooth matching condition in the design process in order to realize the correct synchronous meshing of each branch, which is of great significance to ensure its uniform installation and motion synchronization.Aiming at the coaxial six-branch twisted herringbone gear transmission system, this paper establishes a calculation method for the proper meshing conditions of each branch on the basis of considering the movement synchronization of each branch and preventing geometric interference.In addition, the calculation of gear allocation was carried out for a ship's power transmission system, and a parameter scheme that satisfies the requirements of transmission ratio, concentricity and synchronous meshing was obtained.The correctness of the calculation method of tooth matching in this paper is verified by three-dimensional modeling. This method has universal application value to the tooth matching design of other coaxial multi-branch gear transmissions.
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Sharipov, V. M., Yu S. Shchetinin, S. V. Gaev e O. V. Troshkin. "POWER ANALYSIS OF DUAL-FLOW HYDROMECHANICAL GEARS". Traktory i sel hozmashiny 84, n. 2 (15 febbraio 2017): 35–41. http://dx.doi.org/10.17816/0321-4443-66273.
Testo completoAbstract (sommario):
Dual-flow hydromechanical transmissions are becoming increasingly widespread in the designs of modern land transport and traction machines (tractors, automobiles and high-speed crawler vehicles). This happens mainly due to the desire to increase the efficiency of transmission, although the capabilities of dual-flow hydromechanical transmissions are broader. In order to select a dual-flow hydromechanical transmission scheme in relation to specific operating conditions, it is necessary to know the advantages and disadvantages of various schemes, their potential capabilities. The evaluation of the operation of each circuit can be made on the basis of their kinematic and force analysis. The article deals with 12 dual-flow schemes of hydromechanical transmission with a differential element in inlet and outlet with a mixed meshing of gears, the results of the power analysis are shown. For the estimated parameters of a double-flow hydromechanical transmission were taken: й - power ratio of a double- гмп flow hydromechanical transmission; ан - coefficient of loading of the pump wheel of the torque converter; ам -load factor of the mechanical branch of the closed transmission contour; аa - load factor of the solar gear of the three-link differential mechanism. For each of the schemes considered, analytical dependencies of the estimated parameters on the internal parameters of the hydromechanical transmission were obtained. For the parameters were used the characteristic k of planetary gear set, power йгт and kinematic игт gear ratios of torque converter. It is assumed that, at the boundaries of the range й = да and й = 0. Calculations have been performed to determine the parameters й , гмп гмп гмп ан , ам u аа for different values of k and й , results of which made possible to evaluate the potential transforming properties of the schemes of two-flow hydromechanical transmissions independently of the model of the used hydrotransformer.