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]

Thermal and Dynamic Characterization of Wet Clutch Engagement With Provision for Drive Torque

2000 ◽  
Vol 123 (2) ◽  
pp. 313-323 ◽  
Author(s):  
M. Mansouri ◽  
M. Holgerson ◽  
M. M. Khonsari ◽  
W. Aung
Keyword(s):  
Thermal Stresses ◽  
Automatic Transmission ◽  
Thermal Characteristics ◽  
Element Model ◽  
Large Temperature ◽  
Drive Torque ◽  
Lubrication Regimes ◽  
Clutch Engagement ◽  
Wide Range ◽  
Wet Clutch

Wet clutches that handle the gearshifts in automatic transmission undergo severe thermal stresses due to the occurrence of large temperature gradients during engagement. To accurately design wet clutches, better models to simulate the engagement process are needed. This work presents a finite element model for simulating wet clutch engagements. The total friction coefficient was used to describe the different lubrication regimes that a wet clutch engagement undergoes. The model also includes provision for drive torque that realistically simulates the engine torque of a car. The results of the simulations are successfully verified by comparison with laboratory experiments on a testrig specially designed to accommodate the drive torque, covering a wide range of typical engagements. Excellent agreement between experiment and simulations is reported in terms of both the dynamics of the engagement and the thermal characteristics. The results are indicative of the utility of the model as a useful engineering tool.

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.

scholarly journals Dynamic Temperature Rise Mechanism and Some Controlling Factors of Wet Clutch Engagement

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zhang Zhigang ◽  
Shi Xiaohui ◽  
Guo Dong
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
Transmission Model ◽  
Radial Temperature ◽  
Dynamic Temperature ◽  
Heat Transfer Theory ◽  
Clutch Engagement ◽  
Friction Disk ◽  
Wet Clutch ◽  
Three Components

The friction transmission model of wet clutch is established to analyze the friction transmission mechanism of its engagement. The model is developed by applying both the average flow model and the elastic contact model between the friction disk and separator plate. The key components during wet clutch engagement are the separator plate, friction disk, and lubricant. The one-dimension transient models of heat transfer in radial direction for the three components are built on the basis of the heat transfer theory and the conservation law of energy. The friction transmission model and transient heat transfer models are coupled and solved by using the Runge-Kutta numerical method, and the radial temperature distribution and their detailed parametric study for the three components are conducted separately. The simulation results show that the radial temperature for the three components rises with the increase of radius in engagement. The changes in engagement pressure, lubricant viscosity, friction lining permeability, combined surface roughness RMS, equivalent elasticity modulus, difference between dynamic and static friction coefficients, and lubricant flow have important influence on the temperature rise characteristics. The proposed models can get better understanding of the dynamic temperature rise characteristics of wet clutch engagement.

scholarly journals PENGARUH KENAIKAN TEMPERATUR TERHADAP ANGKA VISKOSITAS OLI SEPEDA MOTOR MATIC

KOMPUTEK ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Nasroni Nasroni ◽  
Sudarno Sudarno ◽  
Munaji Munaji
Keyword(s):  
Temperature Rise ◽  
Automatic Transmission ◽  
Transmission System ◽  
Effect Of Temperature ◽  
Oil Viscosity ◽  
Gear Mechanism ◽  
Transmission Gear

The transmission system on the vehicle is divided into manual and automatic transmission. Both have different oil and oil functions. Automatic motorcycle oil serves to lubricate the engine and as a conductor of the transmission gear mechanism. This study aims to determine the effect of temperature rise and what percentage changes in automatic motorcycle oil viscosity figure. Research on the effect of temperature on the viscosity number of some types of automatic motorcycle oil has been done. Testing is done by viscometer of falling ball. Measurements were carried out at a temperature of 27 and a temperature of 85 . From the results of several types of motorcycle oil research automatically. Viscosity Enduro Matic SAE 10W-30 is 0.0346 poise, Top 1 Action Matic SAE 10W-40 is 0.0240 poise, BM 1 Matic SAE 10W- 30 is 0.0240 poise, Federal Matic SAE 10W-30 is 0.0191 poise, Motul Scooter SAE 10W-30 Is 0.0193 poise and Castrol Activ Matic SAE 10W-30 is 0.0213 poise. Percentage of Decrease is Enduro Matic SAE 10W-30 3.26%, Top 1 Action Matic SAE 10W-40 3.02%, BM 1 Matic SAE 10W-30 3.4%, Federal Matic SAE 10W-30 3.5%, Motul Scooter SAE 10W-30 3.44% And Castrol Activ Matic SAE 10W-30 3.2%. 

In-Vehicle Characterization of Wet Clutch Engagement Behaviors in Automatic Transmission Systems

2018 ◽  
Vol 11 (5) ◽  
pp. 369-375 ◽  
Author(s):  
Hiral Haria ◽  
Gregory M. Pietron ◽  
Jason Meyer ◽  
Yuji Fujii ◽  
Pengchuan Wang ◽  
...  
Keyword(s):  
Automatic Transmission ◽  
Transmission Systems ◽  
Clutch Engagement ◽  
Wet Clutch

scholarly journals Evaluation of thermo-oxidized Jatropha bio-oil in lubrication of actual wet clutch materials

2020 ◽  
pp. 135065012098146
Author(s):  
Leonardo I Farfan-Cabrera ◽  
Ezequiel A Gallardo-Hernández ◽  
José Pérez-González ◽  
Benjamín M Marín-Santibáñez ◽  
Roger Lewis ◽  
...  
Keyword(s):  
Automatic Transmission ◽  
Viscosity Index ◽  
Jatropha Oil ◽  
Oxidative Aging ◽  
Lubrication Regime ◽  
Viscosity Increase ◽  
Bio Oil ◽  
Wet Clutch ◽  
Transmission Fluid ◽  
Pin On Disk

In this work, an assessment of the performance of thermo-oxidated Jatropha oil as a lubricant for actual wet clutch materials was performed and compared with a commercial automatic transmission fluid. For this, Jatropha oil, a commercial automatic transmission fluid and a blend of 20 vol% Jatropha oil–80 vol% automatic transmission fluid were subjected to thermo-oxidative aging at 26 °C and 100 °C, followed by a pin-on-disk testing with disk samples from an actual wet clutch. Evaluation of the film thickness at the sliding interface resulted in a boundary lubrication regime for all the tests. The changes in oxidation, viscosity, and a viscosity index of the samples were evaluated along with friction coefficients at various sliding speeds. Jatropha oil was the most sensitive to thermo-oxidation. Jatropha oil and the blend showed a higher viscosity increase than automatic transmission fluid with thermo-oxidation, while the viscosity index of all oils was decreased considerably, Jatropha oil and the blend being the most reduced. Finally, the anti-shudder property, as measured by the change in the friction coefficient with a sliding speed, of Jatropha oil and automatic transmission fluid was improved by thermo-oxidation at 26 °C but worsened at 100 °C, meanwhile it was barely affected in the blend. Therefore, these results indicate that using pure Jatropha oil as automatic transmission fluid would be unsuitable, but blending it with automatic transmission fluids in specific proportions may be apposite for improving the friction properties of wet clutches even under thermo-oxidative conditions.

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