Kinematic and Dynamic Analyses of Tripod Sliding Universal Joints

Abstract

The kinematic and dynamic equations of the tripod sliding universal joint were established in order to understand the kinematic and dynamic properties thereof, and then the effects of the joint angle, the rotating radius of the slide rods, the length of the output shaft on the fluctuation of the joint angle, the output angle error, and the relative displacements of the slide rods were investigated. Meanwhile, the main dynamic curves were also obtained. In this work, each obtained curve is basically similar to a sinusoid. The joint angle, the output angle error, the forces or torques of two bearings of the input and output shafts as well as the load torque have a threefold frequency. The relative displacement of the slide rod to the tripod has a twofold frequency. The relative displacement of the slide rod to the hole of the input shaft and each component force acting on the tripod arms and holes of the input shaft have a simple frequency. The fluctuation amplitudes of the joint angle and relative displacements of the slide rods as well as the output angle error increase with the increase of the joint angle or the rotating radius of the slide rod. Increasing length of the output shaft decreases the fluctuation amplitudes of the joint angle and output angle error. However, the relative displacements of the slide rods hardly depend on this length.