Influence of operating conditions on friction and temperature characteristics of a wet clutch engagement

Tribotest ◽  
2000 ◽  
Vol 7 (2) ◽  
pp. 99-114 ◽  
Author(s):  
Mikael Holgerson
Keyword(s):  
Operating Conditions ◽  
Temperature Characteristics ◽  
Clutch Engagement ◽  
Wet Clutch

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.

The influence of repeated high-energy engagements on the permeability of a paper-based wet clutch friction material

2017 ◽  
Vol 231 (12) ◽  
pp. 1574-1582
Author(s):  
Niklas Lingesten ◽  
Pär Marklund ◽  
Erik Höglund
Keyword(s):  
High Energy ◽  
Friction Material ◽  
Sliding Surface ◽  
Steel Core ◽  
Interface Surface ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Oil Flow ◽  
Contradictory Behavior ◽  
Test Cells

The behavior of a wet clutch during engagement is of great importance to the durability of the clutch and the drivability of a vehicle. While many different factors influence the engagement behavior, the focus of this paper is to investigate only one factor, the permeability of the wet clutch friction material. Two test cells for measuring the permeability of friction material mounted on clutch discs have been developed. The test cells were then used to examine the effect of clutch material ageing through clutch engagement on the permeability of the material. The tests were performed on full size friction discs including the steel core prior and subsequent to testing in a wet clutch engagement test rig. The ability of the friction material to allow for oil flow both through the sliding surface layer and the bulk of the material was measured. The results indicate that repeated clutch engagements will increase the bulk permeability. However, the repeated engagements will decrease the ability to pass fluid through the friction material sliding surface. This contradictory behavior could be explained by a combination of an increase in pore size through repeated compression and the surface glaze clogging of the friction interface surface pores.

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.

Robust predictive control design for optimal wet-clutch engagement

2012 ◽  
Author(s):  
A. Dutta ◽  
R. De Keyser ◽  
C. M. Ionescu ◽  
J. Stoev ◽  
G. Pinte ◽  
...  
Keyword(s):  
Predictive Control ◽  
Control Design ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Robust Predictive Control

scholarly journals Integrated Thermal and Dynamic Analysis of Dry Automotive Clutch Linings

2019 ◽  
Vol 9 (20) ◽  
pp. 4287 ◽  
Author(s):  
Theofilos Gkinis ◽  
Ramin Rahmani ◽  
Homer Rahnejat
Keyword(s):  
Thermal Performance ◽  
Pressure Profile ◽  
Rear Wheel ◽  
Operating Conditions ◽  
Contact Heat ◽  
Stick Slip ◽  
Powertrain System ◽  
Clutch Engagement ◽  
Lining Material ◽  
System Temperature

Optimum operation of clutch systems is dictated by their dynamic as well as thermal performance. Both of these aspects are closely related to the interfacial frictional characteristics of the clutch lining material, which also affects the noise, vibration and harshness response of the entire vehicular powertrain system. Severe operating conditions such as interfacial clutch slip and increased contact pressures occur during clutch engagement, leading to generation of contact heat, and higher clutch system temperature. Therefore, any undesired oscillatory responses, generated during clutch engagement, such as take-up judder phenomenon can exacerbate generated heat due to stick-slip motion. The paper presents an integrated thermal, and 9-DOF dynamic model of a rear wheel drive light truck powertrain system. The model also includes experimentally measured clutch lining frictional variations with interfacial slip speed, non-linear contact pressure profile and generated surface flash temperature. It is shown that severe torsional oscillations known as take-up judder lead to an increased overall clutch temperature. It also shows that ageing of clutch lining material alters its dynamic and thermal performance.

scholarly journals Research on trajectory tracking control for wet clutch engagement based on SMC

2011 ◽  
Vol 15 ◽  
pp. 2742-2746 ◽  
Author(s):  
Hu Hongwei ◽  
Wu Hequan ◽  
Zhang Zhiyong ◽  
Shao Yimin
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Trajectory Tracking Control ◽  
Clutch Engagement ◽  
Wet 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.

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