Research on axial friction forces induced by automobile double roller tripod joints

The double roller tripod joint (DRTJ) will generate two axial friction forces during the operation, namely the generated axial force (GAF) and the plunging resistant force (PRF). The GAF will cause “Shudder” of the vehicle, and the PRF will cause “Idle booming” of the vehicle. The NVH (Noise, Vibration and Harshness) problem caused by the two axial friction forces is particularly prominent in new energy vehicles. In order to study the influence of the operating conditions on the axial friction forces, a test bench for testing the axial friction forces of the DRTJ is established, and the testing methods for the GAF and the PRF of the DRTJ are proposed. The relationship between the axial friction forces and the joint bending angle, the transmitted torque, and the rotation speed is tested and analyzed. In order to predict the axial friction forces more effectively, a multi-body dynamics model of the DRTJ is proposed. The validity of the multi-body dynamics model is verified by the test, and the influence of the structure parameters of the DRTJ on the axial friction forces is subsequently analyzed using the multi-body dynamics model. Taking the structural parameters as design parameters, an effective method of optimizing the axial friction forces by optimizing the contact stress between the outer rollers and the raceways is proposed based on the finite element analysis method and the response surface method. The research results indicate that the axial friction forces can be reduced effectively using the proposed optimization method, which can provide an important reference for the design optimization of the DRTJ.