Research on Drag Torque of High Relative Speed Open Wet Clutch of Vehicle

Abstract

The open transmission wet clutch plays a significant role in determining transmission efficiency. The previous model can't calculate high speed difference drag torque,and can't consider about grooves of friction disks. Wet clutch is the research object. A modified Reynolds equation with centrifugal force is built. At the same time a three-dimensional domain,which include the information about groove type is built. The calculation includes full consideration of the pressure gradient along circumferential and radial direction. The equation solved by finite volume method. New solve method is used: by the given flow rate,different speed and pressure distribution,the equal outer radius is calculated,and then can calculate the drag torque. The drag torque curve in wider speed difference range agrees qualitatively with the experimental result. At the end,the new model is used to investigate the effects of the depth of grooves,the area ratio of grooves,the flow rate and the number of grooves on the drag torque of wet clutches. The research result shows that the drag torque will decrease with the depth of grooves increase; will decrease with the area ratio of grooves increase; will increase with the flow rate increase and will decrease with the number of grooves increase.