Numerical and experimental research on engagement process of wet multi-plate friction clutches with groove consideration

Abstract

A numerical model is established to investigate the effects of the influencing factors such as design parameters and operating conditions on the performance and behavior of the engagement process of the wet clutch based on the Navier–Stokes equations, contact mechanics, and heat transfer theory. A finite element contact model called KE contact model is used to analyze the rough contact during engagement process and thermal effect on the viscosity is considered based on heat transfer theory. The integration of the grooving into the simulation and the method of coupled finite element by domain decomposition of groove and ungrooved areas are put forward to facilitate the analysis. The experimental results agree well with the numerical model which takes the normal pressure, the temperature of ATF, relative revolution speed, the permeability and the groove geometry into account. The results of numerical simulation and the experiment indicate that the applied pressure not only affects the engagement time, but also has influence on the value of the engagement torque. Besides, the engagement time is roughly proportional to the relative revolution speed. The influencing factors such as the temperature of ATF, the permeability, grooves, the torque judders and effects of PID control parameters are also discussed in the paper. The performance and behavior of the engagement of the wet clutch were studied by two methods of numerical calculation and experimental research, which make the working process of the wet clutch more detailed.

Study on the Influence Factors Upon the Propensity to Stick-Slip Phenomenon During Vehicle Start-Up Process

“…There are resistive forces opposing the motion of the vehicle, some exist from the beginning of the motion and others build as the vehicle's speed increases. The resistive forces can be categorized into four types: frictional, air resistance, acceleration, and gravitational which is also called grade force [30] The resistive torques can be calculated by (16). where, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, θ is the slope angle, C D is the aerodynamic force coefficient, A is the project area of the vehicle, ρ is the density of the air, v is the velocity, δ is the acceleration coefficient, and r W is the radius of wheel.…”

Structural Design and Friction Performance Test of a New Conical Groove Friction Disks in Wet Clutch

“…Wang [19,20] presented a mathematical model of the drag torque of the disengaged wet clutch by considering the effects of grooves and waviness on the friction plates. Wu [21,22] established a comprehensive numerical model, which took radial grooves, hydrodynamic, mechanics of elasticity, plasticity contact, and thermal effect into consideration. This model solved the domain decomposition of groove area by coupled finite element method.…”

Analytical simulation of influential parameters affecting grooved wet clutches performance underdisengagement condition

“…A vast number of research have been conducted to study the effects of clutch geometry, material, and fluid characteristics in particular ATFs on wet clutches performance with emphasis on drag torque and air ratio in disks interface under two-phase flow [4][5][6][7] . In addition, the impact of clutch engagement time and transmitted torque have been investigated [8][9][10] .…”