高转速差车用湿式离合器带排转矩特性研究

车用湿式离合器的带排工况对车辆传动系统效率影响很大，过去建立的模型无法计算高转速差区域及不同摩擦片沟槽形式的带排转矩。以车用湿式离合器为研究对象，建立考虑离心力的修正雷诺方程，同时建立能够包含沟槽形式信息的三维求解区域，求解过程中考虑润滑油压力沿摩擦片周向的压力分布梯度，采用有限体积法进行求解。在计算带排转矩时采用新的求解方法，通过已知的供给流量和转速差经过压力分布求解获得润滑油膜的等效外半径，进而求得带排转矩。在更宽广的转速差范围内进行计算结果与试验结果的对比，两者基本吻合。研究不同沟槽深度、不同沟槽槽占比、润滑油流量和沟槽数目对离合器带排转矩特性的影响规律。研究结果表明，带排转矩随沟槽深度的增大而减小、随槽占比的增大而减小、随润滑油流量的增大而增大、随沟槽数目的增大而减小。

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

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.