The drag characteristics prediction of multi-plate frictional wet clutches in vehicle transmissions.

The multi-plate frictional wet clutch is one of the most important components in automatic transmissions. With the increasing of the rotational speed, the phenomena is tested that the drag torque firstly increases to the peak torque, and then decreases to a lower level and maintains within a certain range, and finally increases rapidly again. A fluid-structure coupled model of the whole wet clutch was established. The simulation results show that the pressure distribution is obviously nonuniform either on the frictional surface or between two sides of the clutch plate. The nonuniform pressure would cause the axial and deflection motion and so the impact would occur, which is the main reason for the drag torque's increasing under high rotational speed. Based on the simulated results, a prediction model was built with the direct artificial neural network method. The test results show that the drag characteristics prediction model is effective and fast. [ABSTRACT FROM AUTHOR]