Finite Element Analysis And Optimization Of X-ring For Servo Mechanism

The X-ring used in servo mechanism plays a vital role on the sealing performance. The performance of X-ring directly determines the normal operation of the servo mechanism and the whole device. Recently, there are a lot of research on the sealing performance of rubber seals, but little on the systematic study of X-ring, especially on the various factors. Therefore, this paper aims at various factors of X-ring in the actual conditions and conducts a detail analysis of its mechanical properties and sealing performance based on ABAQUS.First, a non-linear finite element analysis for X-ring in the static state is conducted according to the Mooney-Rivlin constitutive models of rubber materials. According to the actual operating conditions, the effect of different fluid pressures, compression ratios and sealing gaps are analyzed on its stress contribution. Then the cross-sectional structure parameters are optimized and discussed. We have obtained that X-ring has a better stress state when the concave radius is 0.8mm.Second, we derive the oil film thickness and leakage in the reciprocating motion according to the Reynolds equation of quasi-one-dimensional flow. We obtain the film pressure on the sealing surface based on elastic hydrodynamic model and the analysis of X-ring under reciprocating state. Then we calculate the film thickness in the sealing gap and the leakage in a cyclical.And the last, we can obtain its compression set by the compression set test of rubber material at low temperature. The model of considering the impact of compression set is analyzed under different conditions based on ABAQUS. And the two models are analyzed and compared. The results show that:the compression set have some impact on the stress state of the X-ring when the fluid pressure or the compression ratio is low.