三轴向振动台运动耦合装置的参数优化

Parameter Optimization of the Cross-Coupling Unit in Tri-axis Vibration Exciter

通过建立三轴向振动台运动耦合装置的传递模型,根据需求频率范围合理选择运动耦合装置刚度。采用有限元方法求解气体润滑问题,仿真分析了供气压力和气膜厚度对气体静压轴承刚度的影响。结果表明,气体静压轴承的刚度随着供气压力的增大而增大,在特定的供气压力下存在一个使气体静压轴承的刚度取得极值的气膜厚度极值点。在此基础上,优化得到一组满足运动耦合装置传递特性要求的供气压力和气膜厚度参数,并通过原理样机进行了验证。实验结果表明,优化得出的运动耦合装置参数满足传递特性要求。

The cross-coupling unit is the key component of the tri-axis vibration exciter.The static pressure bearing is applied in the cross-coupling unit to transmit vibration and guide motion for independent x-,y-,z-axial vibration.The transmission model of the cross-unit is modelled for stiffness selection according to the desired frequency range.A finite element method is introduced to solve the Reynolds equation of gas lubrication problem.Influence of air supply pressure and air film thickness on the stiffness of the air static pressure bearing is discussed.The stiffness of the static pressure bearing increases with the air supply pressure and there exists an extreme point of the film thickness where the static pressure bearing has the maximum stiffness at a given air supply pressure.On this basis,the parameter optimization of the crosscoupling unit is realized with a set of optimized air supply pressure and air film thickness.Experiments are carried out to and the results show that the optimized parameters can meet transmission characteristic requirement of the cross-coupling unit.