Visualizaion of Cavitation Phenomena in 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.

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Research on the Wet Clutch Engagement Torque

Volume 7: 2nd Biennial International Conference on Dynamics for Design; 26th International Conference on Design Theory and Methodology ◽

10.1115/detc2014-34179 ◽

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.

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Hybrid Neural Network for Modeling Automotive Clutches

10.1115/imece1999-0034 ◽

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

Tribotest ◽

10.1002/tt.3020070202 ◽

2000 ◽

Vol 7 (2) ◽

pp. 99-114 ◽

Cited By ~ 6

Author(s):

Mikael Holgerson

Keyword(s):

Operating Conditions ◽

Temperature Characteristics ◽

Clutch Engagement ◽

Wet Clutch

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A Novel Comprehensive Model of Wet Clutch During the Engagement Process

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/825/1/012011 ◽

2020 ◽

Vol 825 ◽

pp. 012011

Author(s):

Baoshan Peng ◽

Heyan Li ◽

Jikai Liu

Keyword(s):

Comprehensive Model ◽

Wet Clutch ◽

Engagement Process

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

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650117700807 ◽

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.

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Rig Test and Analysis of Dynamic Engagement Process of Wet Clutch

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.945-949.1461 ◽

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.

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Optimal control for jitter suppression of clutch engagement in upshift process of electric vehicles

Advances in Mechanical Engineering ◽

10.1177/1687814016674847 ◽

2016 ◽

Vol 8 (12) ◽

pp. 168781401667484

Author(s):

Junqiu Li ◽

Yihe Wang ◽

Yizheng Wang

Keyword(s):

Optimal Control ◽

Dynamic Model ◽

Automatic Transmission ◽

Friction Torque ◽

Dynamic Responses ◽

Lumped Mass ◽

Virtual Displacement ◽

Motor Torque ◽

Clutch Engagement ◽

Engagement Process

In the shift process of large-order automatic transmission, jitter phenomenon is common in clutch engagement process, which greatly affects the ride comfort of the vehicle. In this article, the jitter dynamic model of clutch engagement process was established with lumped mass method and virtual displacement principle. Specific to clutch engagement stage, the optimal control of the coordination between driving motor and wet clutch was studied. In accordance with the jitter dynamic model, the state–space equation with controlling variables of motor torque and clutch friction torque was established. In this optimization problem, the torsion angle, torsion angular velocity, and shift jerk are selected as optimization targets. Utilizing the linear quadratic optimal control theory, the optimal trajectory of motor torque and clutch friction torque was obtained. Aiming at the dynamic responses in clutch engagement process, the optimal control in different conditions of weight coefficients, initial torsion angles, and resistance torques was studied. Results showed that the optimal control strategy could obviously reduce the jitter; in addition, the weight coefficient should be determined according to actual situation reasonably.

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Numerical Simulation of Engagement of Paper Based Wet Clutch Facing

Journal of Tribology ◽

10.1115/1.2927201 ◽

1994 ◽

Vol 116 (2) ◽

pp. 232-237 ◽

Cited By ~ 83

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.

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