研制了1种针对径向轴承的微载荷摩擦试验机,介绍了其工作原理及结构,即利用外加载荷抵消浮动测试架重量以施加微小载荷,并利用激光位置传感器(PSD传感器)实现无接触位移测量;同时测量了摩擦副的转动角度并计算出摩擦系数;采用摩擦转角测量法和外加力矩平衡摩擦法测量微载荷下的摩擦性能,以测量时间末端位置作为位置基准,通过极限偏载平衡进行载荷标定.结果表明:微载荷摩擦试验机可应用于径向轴承在微小载荷下的摩擦力测量;可以通过在较大范围内设置结构参数来研究径向轴承的摩擦特性;并可利用数据采集技术研究速度和载荷连续变化条件下的摩擦性能.
A new type of tribometer for experimental study of tribological performance of journal bearings under micro-load was established, which utilizes the method of load counterpoise to obtain mechanics equilibrium state of the test rig so as to apply load from zero. A laser device and a PSD sensor were used to measure the displacement and friction force with high precision without contact. The friction coefficient is obtained from the frictional angle of the cantilever and displacement of PSD sensor. Two methods were used for the measurement of friction coefficient, friction angle and frictional torque equilibrium. The former measures the angle resulting from friction, and the latter utilizes the exterior torque to poise the rig mechanics state under the rotating condition. The zero location on PSD is at the tail end of test process. Through reaching one-side weight limitation with pulley at the static state, calibration of load was completed. The tribometer can measure friction, stick-slip of journal beatings under micro-load. Furthermore, measurements of wider range of load and/or friction coefficient were achieved by setting the structure parameters of the tribometer. With data sampling and processing capability, bearing bulk temperature and friction coefficient can be obtained continuously with adjustable load or/and speed.