Simulation to Estimate the Output Torque Characteristics and Temperature Rise of a Transmission Wet Clutch during the Engagement Process

2018 ◽  
Author(s):  
Syeda Faria Mahmud ◽  
Shahjada A. Pahlovy ◽  
Makoto Ogawa
Keyword(s):  
Temperature Rise ◽  
Output Torque ◽  
Wet Clutch ◽  
Engagement Process

Modeling and experimental research on engaging characteristics of wet clutch

2019 ◽  
Vol 71 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Yanzhong Wang ◽  
Yuan Li ◽  
Yang Liu ◽  
Wei Zhang
Keyword(s):  
Contact Surface ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Lubricating Oil ◽  
Centrifugal Effect ◽  
Element Analysis ◽  
Content Type ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Engagement Process

PurposeTo gain in-depth understandings of engaging characteristics, the purpose of this paper is to improve the model of wet clutches to predict the transmitted torque during the engagement process.Design/methodology/approachThe model of wet clutch during the engagement process took main factors into account, such as the centrifugal effect of lubricant, permeability of friction material, slippage factor of lubricant on contact surface and roughness of contact surface. Reynolds’ equation was derived to describe the hydrodynamic lubrication characteristics of lubricant film between the friction plate and the separated plate, and an elastic-plastic model of the rough surfaces contact based on the finite element analysis was used to indicate the loading force and friction torque of the contact surface.FindingsThe dynamic characteristics of wet clutch engagement time, relative speed, hydrodynamic lubrication of lubricating oil, rough surface contact load capacity and transfer torque can be obtained by the wet clutch engagement model. And the influence of the groove shape and depth on the engaging characteristics is also analyzed.Originality/valueThe mathematical model of the wet clutch during the engagement process can be used to predict the engaging characteristics of the wet clutch which could be useful to the design of the wet clutch.

Rig Test and Analysis of Dynamic Engagement Process of Wet Clutch

2014 ◽  
Vol 945-949 ◽  
pp. 1461-1464
Author(s):  
Han Yu Jin ◽  
Xiu Sheng Cheng ◽  
Xiu Feng Song
Keyword(s):  
Mathematical Model ◽  
Experimental Verification ◽  
Constant Pressure ◽  
Simulation Analysis ◽  
Test Rig ◽  
Wet Clutch ◽  
Engagement Process ◽  
Working Principle ◽  
The Mathematical Model

The working principle of wet clutch was analyzed and the mathematical model was established for torque deliver. Experimental verification and simulation analysis was carried out for the clutch model in the situation of constant pressure engaging process. An efficiency examination of wet clutch implemented on the test rig and provided theory evidence for pressure precisely control.

Numerical Simulation of Engagement of Paper Based Wet Clutch Facing

1994 ◽  
Vol 116 (2) ◽  
pp. 232-237 ◽  
Author(s):  
Shinichi Natsumeda ◽  
Tatsuro Miyoshi
Keyword(s):  
Hydrodynamic Lubrication ◽  
Compressive Strain ◽  
Viscosity Reduction ◽  
Frictional Heat ◽  
Asperity Contact ◽  
Wet Clutch ◽  
Engagement Process ◽  
Torque Curve ◽  
The Many ◽  
Made In

Theoretical analysis was carried out on the engagement process of a paper based wet clutch. The annular multidisk clutch in a SAE#2 tester was chosen as an example. The average flow model on partial hydrodynamic lubrication proposed by Patir and Cheng was employed for the analysis of squeeze motion taking the permeability, the compressive strain, and the asperity contact of paper facing into account. Simultaneously, the equations of heat conduction were solved to calculate the viscosity reduction due to frictional heat generation. The theoretical torque curve agreed qualitatively with the experimental one in spite of the many assumptions made in this analysis.

Research on the Wet Clutch Engagement Torque

2014 ◽  
Author(s):  
Yingying Zhang ◽  
Changle Xiang
Keyword(s):  
Rough Surface ◽  
Automatic Transmission ◽  
Squeeze Film ◽  
Real Contact Area ◽  
Asperity Contact ◽  
Time Flow ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Lubrication Oil ◽  
Engagement Process

The driving performance of the vehicle with automatic transmission is influenced by the performance of the wet clutch directly. But at present it is still a challenge to build a reliable predictable model for the torque of the engagement process of the wet clutch. Focusing on the wet clutch of vehicle, this paper starts from mechanism analysis, and a modified Reynolds equation with the consideration of the centrifugal force of the squeeze-film is established. In the model, we can consider the speeds of the friction and separator plates independently. At the same time, flow factors have been used to research the impacts of rough surface on the flow of the lubrication oil. In the three-dimensional solution domain, the circumferential pressure gradient of lubrication oil is considered. The model is solved with the finite volume method. The simulation of the torque of the asperity contact calculates the real contact area changed with the engagement process, and the microscopic texture direction of rough surface is considered. Subsequently, the squeeze-film flow model is combined with the asperity contact model to create an integrated clutch engagement model. Finally, the influence of applied force, viscosity of lubrication oil, friction material, the depth of grooves and the width of the grooves are investigated. Based on the comparison with the experimental data, the performance of the proposed model is found satisfactory. Because in this model more detail properties of material and geometric features of the friction plate are include, the wet clutch model developed in this research can become a baseline model for the prediction of the engagement behavior of a real wet clutch. The present model may become an efficient alternative to laboratory testing and lead to designs that can not be envisioned by other approaches.

Research on Temperature Rise of Wet Clutch Based on Multi-Field Coupling

2019 ◽  
Author(s):  
Bangzhi Wu ◽  
Datong Qin ◽  
Jianjun Hu ◽  
Qing Zhang
Keyword(s):  
Temperature Field ◽  
Numerical Calculation ◽  
Flow Field ◽  
Field Distribution ◽  
Working Conditions ◽  
Temperature Rise ◽  
Automatic Transmission ◽  
Calculation Model ◽  
Field Coupling ◽  
Wet Clutch

Abstract Wet clutch is widely used in vehicle power transmission, especially in dual clutch automatic transmission. However, due to the unclear understanding of clutch temperature distribution and its influencing factors, the clutch is prone to excessive temperature rise or even wear under severe working conditions or continuous starting conditions. In this paper, the finite element model of stress field distribution of friction pair is established by considering the non-uniform fixed constraint of clamping spring and the non-uniform contact of hydraulic cylinder. Based on the inclined groove structure of the friction plate, the numerical calculation model of the flow field in the groove is established by the finite volume method. On this basis, considering the time-varying characteristics of stress distribution and cooling flow field distribution of clutch friction pairs, a numerical calculation model of clutch temperature field is established, and a multi-field coupling calculation method of clutch is proposed. The distribution of temperature field under different working conditions during clutch engagement is obtained by numerical calculation. The results show that the temperature rise of clutch depends on the target speed of the clutch driving end and the load on the driven end. The research results can provide guidance for the design and control of the clutch.

Optimizing the Smoothness and Temperatures of a Wet Clutch Engagement Through Control of the Normal Force and Drive Torque

1999 ◽  
Vol 122 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Mikael Holgerson
Keyword(s):  
Temperature Rise ◽  
Normal Force ◽  
Dynamic Performance ◽  
Automatic Transmission ◽  
Test Rig ◽  
Friction Characteristics ◽  
Drive Torque ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Transmission Gear

Automatic transmission gear shifts are handled by wet clutches, which determine the smoothness. The clutch face temperatures during the engagements are often an important parameter for the total clutch life. A wet clutch test rig has been used to evaluate how a wet clutch engagement can be improved in terms of smoothness and temperature. This was performed with control based upon knowledge about friction characteristics and dynamic performance. The parameters used for control were the drive torque and the normal force on the clutch. By drive torque shut-off and reduced normal force the torque variations were greatly reduced and the temperature rise was decreased by 37%. [S0742-4787(00)01601-5]

Hybrid Neural Network for Modeling Automotive Clutches

1999 ◽  
Author(s):  
V. Parvataneni ◽  
M. Cao ◽  
K. W. Wang ◽  
Y. Fujii ◽  
W. Tobler
Keyword(s):  
Neural Network ◽  
Hybrid Model ◽  
Hybrid Network ◽  
Hybrid Neural Network ◽  
Physical Knowledge ◽  
The Neural Network ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Engagement Process ◽  
Artificial Neural Network Ann

Abstract In this paper, artificial neural network (ANN) based models to capture the dynamic engagement torque of a wet clutch system are developed and analyzed. A two-layer recurrent ANN with output feedback is chosen as the baseline architecture since its simplicity allows easy implementation and efficient execution. Although this model exhibits good performance in capturing the overall mean level of the engagement torque as a function of time, it is unable to predict some of the important clutch dynamics behaviors. To improve the performance, additional neurons that represent the first principles of the clutch engagement process are incorporated into the neural network model. In other words, a hybrid model in which physical knowledge is implicitly embedded within the ANN architecture is derived. This hybrid model is trained and tested with experimental data. The results show that the performance of the hybrid network is much superior to that of the baseline ANN. It can successfully capture not only the trends, but also the detailed characteristics of the clutch engagement torque as a function of time.

Thermal Analysis of Lubricating Oil Flow Within a Wet-Disk Clutch

2000 ◽  
Author(s):  
Tien-Chien Jen ◽  
Dan Nemecek
Keyword(s):  
Thermal Analysis ◽  
Nusselt Number ◽  
Temperature Rise ◽  
Separation Of Variables ◽  
Three Dimensional ◽  
Lubricating Oil ◽  
Axial Position ◽  
Outlet Temperature ◽  
Wet Clutch ◽  
Oil Flow

Abstract A combined theoretical and experimental thermal analysis is conducted on the oil flow between the plates of a wet clutch during an extended slip engagement. An analytical model, using the separation of variables technique, is developed to simulate the temperature rise due to the non-conservative friction and relative motion between the steel plates and friction plates of the clutch. A three-dimensional numerical heat transfer and fluid flow model was developed to calculate the velocity and temperature profiles in the oil groove channel. Typical velocity profiles and temperature contours plots are demonstrated. Friction factor and Nusselt number are presented as functions of axial position. The experiment performed included a wet clutch instrumented with thermocouples and installed in a power-shift transmission where the temperature rise during one clutch engagement was measured. The total energy is then estimated by accounting for system inertia, torque and rotating speeds. Finally, the inlet, outlet temperature rises and the averaged Nusselt number of the oil groove are also presented.

The Tribological Characteristics of Cu-Based Friction Pairs in a Wet Multidisk Clutch Under Nonuniform Contact

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Er-hui Zhao ◽  
Biao Ma ◽  
He-yan Li
Keyword(s):  
Friction Coefficient ◽  
Test Bench ◽  
Friction Torque ◽  
Thermal Buckling ◽  
Tribological Characteristics ◽  
Total Output ◽  
Contact Ratio ◽  
Output Torque ◽  
Wet Clutch ◽  
Comprehensive Test

This work is devoted to investigate the effects of thermal buckling on the tribological characteristics of a Cu-based wet clutch by artificially modifying friction pairs into different contact ratios. A thermal lubrication model is provided, and corresponding experiments are conducted on the wet clutch comprehensive test bench. The friction results from measurements and simulations for such modified friction pairs are analyzed. The results show that, as the contact ratio reduces, surface temperature rises obviously, and friction coefficient increases dramatically, so that local friction torque and total output torque grow significantly. In addition, the vibration of the output torque becomes more severe as the contact ratio reduces. Therefore, the nonuniform contact after thermal buckling exacerbates the friction characteristics of friction pairs severely and accelerates the failure of wet clutches.

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