Simulations of Drag Torque in Multi-Plate Wet Clutch Affecting Synchronizers in a TC+AMT Transmission

2014 ◽  
Author(s):  
Shaohua Sun ◽  
Yulong Lei ◽  
Xingzhong Li
Keyword(s):  
Drag Torque ◽  
Wet Clutch

Experimental Research on Drag Torque for Single-plate Wet Clutch

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hu Jibin ◽  
Peng Zengxiong ◽  
Wei Chao
Keyword(s):  
Contact Angle ◽  
Surface Tension Force ◽  
Transmission Efficiency ◽  
Viscous Drag ◽  
Drag Torque ◽  
Two Phase ◽  
Rotating Speed ◽  
Single Plate ◽  
Wet Clutch ◽  
Set Up

The relative motion between the friction and separate plates in a disengaged wet clutch causes viscous drag torque when the lubrication fluid flows through the clearance. Reduction of the drag torque is one of the important potentials for the improvement of transmission efficiency. The objective of this study is to set up an experimental rig to measure drag torque for a single-plate wet clutch. Visualization of the flow pattern in the clearance through transparent quartz was presented. Design factors and lubrication conditions were tested to evaluate the effects on drag torque. A comparison between the nongrooved plate and grooved plate was made. Plates made up of different materials were also tested to reveal the effects caused by the contact angle. Drag torque increases linearly at low rotating speeds and gradually decreases at high rotating speeds. It is confirmed that fluid completely covers the plate surface at a low rotating speed and air mixes with the fluid at a high rotating speed. A low feeding flow rate is useful to reduce drag torque. The reduction of the drag torque benefits from radial and deep grooves compared to a flat plate. A small contact angle near the stationary plate plays an important role in maintaining the oil film, however, it has little effect on the drag torque at the rotating side because the hydrodynamic force becomes dominant compared to the surface tension force. The test results help to build an accurate mathematical model based on two-phase flow lubrication.

scholarly journals Prediction of Drag Torque in a Disengaged Wet Clutch of Automatic Transmission by Analytical Modeling

2016 ◽  
Vol 11 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Shahjada Ahmed Pahlovy ◽  
Syeda Faria Mahmud ◽  
Masamitsu Kubota ◽  
Makoto Ogawa ◽  
Norio Takakura
Keyword(s):  
Analytical Modeling ◽  
Automatic Transmission ◽  
Drag Torque ◽  
Wet Clutch

Calculation and Analysis on Drag Torque of the Wet Clutch

2015 ◽  
Vol 741 ◽  
pp. 91-94 ◽  
Author(s):  
Li Ying Miao ◽  
Xiu Sheng Cheng ◽  
Xue Song Li ◽  
Li Chen Yang
Keyword(s):  
Structural Design ◽  
Theoretical Study ◽  
Influence Factors ◽  
Lubricating Oil ◽  
Drag Torque ◽  
Matlab Simulink ◽  
Simulink Simulation ◽  
Wet Clutch ◽  
Simulation Results

In order to study the drag torque characteristics of wet clutch, the drag torque with no groove friction plates and with radial groove friction plates were analysed separately, and the influence factors of the drag torque such as the lubricating oil temperature, the depth of the groove, the average gap between the friction plates were also discussed. Simulation was carried out in Matlab/Simulink,. Simulation results were compared with experiment results. This study may provide a reference for theoretical study and structural design of wet clutch.

Simulation and experimental study on the influence of oil groove structure on the drag torque of the wet clutch

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengjun Wang ◽  
Wujian Ding ◽  
Xudong Zheng ◽  
Haiqiang Zhu ◽  
Zuzhi Tian ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Reference Object ◽  
Drag Torque ◽  
Content Type ◽  
Oil Film ◽  
Wet Clutch ◽  
Groove Structure ◽  
Dimensional Simulation

Purpose This paper aims to design a single and double throat oil groove structure, which can reduce the drag torque of the wet clutch. Design/methodology/approach A three-dimensional simulation model was established herein using the computational fluid dynamics method. The influence of oil groove structure on the oil film flow field and the drag torque is obtained by a simulation. Findings Compared with the traditional radial oil groove, the results show that the single throat oil groove structure reduces the drag torque by about 24.59%; the double throat oil groove reduces the drag torque by about 47.27%. As the speed difference increases, the average temperature rise of the oil film of the double throat oil groove is 4°C lower than that of the single throat oil groove, indicating that it has good heat dissipation performance. The analysis results were verified by experimental results. Originality/value In this paper, the radial oil groove is taken as the reference object, and the structure of the oil groove is designed and improved. The simulation analysis and experiment verify the rule of the influence of the oil groove structure on the drag torque, which provides a new design idea for reducing the drag torque of wet clutch.

Combined Numerical and Experimental Study on Drag Torque in a Wet Clutch

2011 ◽  
Author(s):  
Youhei Takagi ◽  
Yasunori Okano ◽  
Masatoshi Miyagawa ◽  
Nobuyuki Katayama
Keyword(s):  
Experimental Study ◽  
Volume Fraction ◽  
Rotation Speed ◽  
Automatic Transmission ◽  
Rotating Disk ◽  
Open Boundary ◽  
Drag Torque ◽  
Two Phase ◽  
Frictional Material ◽  
Wet Clutch

The effect of flow field on drag torque in a wet clutch was examined through a combined numerical and experimental study. Three-dimensional hydrodynamic numerical simulations were carried out, and the drag torque was measured experimentally for a single wet clutch pack. Two-phase flow induced by aeration was visualized in the experiment. In the present drag torque test, the main section was consisted of two parallel circular plates. The plate with the frictional material was rotated. The frictional material was divided into some sections, and radial or circumferential grooves were made on the rotating disk. Automatic Transmission Fluid (ATF) was supplied from the axial center, and ejected into the surrounding open boundary. At low rotation speeds, it was found that the oil flow is of single-phase, and the drag torque is linearly proportional to the rotation speed since the shear stress on the clutch plate increased monotonically. In the single-flow regime, the slope of drag torque curve was controlled with the clearance between the clutch plates. The drag torque reached a peak value at a certain rotation speed, and it decreased gradually after the peak. These observed phenomena were due to the aeration from the inner gap on the disk, and the bubble volume fraction was directly related to the drag torque. The peak of drag torque was controlled by both the flow rate of supplied ATF and the arrangement of grooves on the frictional material. It also was found that the smooth ejection of ATF and the enhancement of aeration led to a reduction in the drag torque.

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