涡旋压缩机止推轴承润滑特性研究

Research on lubrication characteristics of scroll compressor thrust bearing

涡旋压缩机止推轴承接触面间油膜黏性剪切力和峰元剪切力耦合作用会动态改变该摩擦润滑特性,为了深入研究两者内部作用机理,运用平均雷诺方程和固体接触理论建立了止推接触面间摩擦润滑理论数学模型;在不同工况下,应用MATLAB软件编程,利用差分迭代和数值积分对止推轴承接触面摩擦润滑理论数学模型进行了数值模拟计算,并在多功能摩擦试验机上开展了涡旋压缩机止推轴承的摩擦润滑试验。结果表明:涡旋压缩机在混合润滑状态下工作时,止推接触面间摩擦系数有最小值,且此接触面间楔形角的形成是产生良好润滑的重要因素。摩擦力理论值与试验值相对误差在1.5%~8.7%之间,平均相对误差为4.5%左右,摩擦系数理论值与试验值相对误差在0.5%~9%之间,其平均相对误差在5%左右,理论计算结果与试验结果吻合良好,验证了所建数学模型的正确性。建立的理论模型可以为进一步完善止推轴承的设计和提高涡旋压缩机机械性能提供理论参考。

The coupling effect of viscous shear force and peak shear force of oil film between the contact surfaces of thrust bearing of scroll compressor can dynamically change the friction and lubrication characteristics of the contact surfaces of thrust bearing.In order to deeply study its internal mechanism,a theoretical mathematical model of friction and lubrication between thrust contact surfaces was established by using the average Reynolds equation and the solid contact theory.The mathematical model of friction and lubrication theory of thrust bearing contact surface was simulated under different working conditions by using difference iteration and numerical integration with Matlab software,and the friction and lubrication test of scroll compressor thrust bearing was carried out on the multifunctional friction testing machine.The results show that the friction coefficient between thrust contact surfaces has a minimum value when the scroll compressor works under the mixed lubrication state,and the formation of wedge angle between bearing contact surfaces is an important factor that produces good lubrication.The relative error between theoretical value and test value of friction force is 1.5%~8.7%,and the average relative error is about 4.5%,the relative error between theoretical value and test value of friction coefficient is 0.5%~9%,and the average relative error is about 5%,so the theoretical calculation results are in good agreement with the experimental results,which verifies the correctness of the established mathematical model.The established theoretical model can provide theoretical reference for further perfecting the design of thrust bearing and improving the mechanical performance of scroll compressor.