A Kinematic Analysis Method of Double Roller Tripod Joints Based on the Principle of Conjugate Surfaces

Abstract

To systematically investigate the contact constraint relationships and the influences of fit clearances on the kinematic performances of a double roller tripod joint (DRTJ), a method for the kinematic analysis of DRTJs is proposed based on the principle of conjugate surfaces. In the proposed method, the constraint relations between rollers and tracks as well as between rollers and trunnions are firstly derived based on the principle of conjugate surfaces. Then, according to the constructed constraint relationships, the kinematic analysis model of a DRTJ considering the influences of fit clearances is established. Next, the effectiveness of the proposed method is validated by measuring the relative displacements and angles between rollers and tracks via experiment. Finally, kinematic analyses are carried out and the main results show that the relative pitch angle between rollers and tracks are always kept as zeroes under any working condition by designing the shapes of rollers' outer surfaces to be semi-toroid. The fit clearances have little influence on the kinematic performances of the DRTJ, thus proper fit clearances between rollers and tracks as well as between rollers and trunnions can be designed to improve the lubricating conditions of the DRTJ.