PTFE编织复合材料重载关节轴承的旋转摩擦特性

介绍了自制的重载摩擦试验机的工作原理及性能特点,其最大加载压力为1000 kN, 旋转与摆动调速范围宽。在转速为2.5 r/min时,测试了PTFE编织复合材料关节轴承承载力与摩擦系数的关系,以及摩擦的时间效应。在承载力为135 MPa时,测试了轴承的磨损曲线、轴承的升温以及摩擦系数随连续摆动时间变化的关系曲线,试验结果表明,其承载力为25~135 MPa时,干摩擦系数为0.038~0.061。通过扫描电镜分析了轴承失效机理,在摆动的过程中PTFE不断被挤出,轴承自润滑功能下降,导致编织基体材料发生磨损。

FRICTION BEHAVIOR OF HEAVY SPHERICAL BEARINGS IN ROTATION OF THE BRAIDED STRUCTURE COMPOSITE

The working principles and properties of a friction tester developed by the authors the are introduced for heavy load. The loading maximum value is 1000 kN. The varying ranges of its velocity are wide. The relationship between the friction coefficient and bearing capacity of the braided composites was explored at 2.5 r/min. Its friction time effect was measured. While the spherical bearing capacity of bearings was 135 MPa, the wear curve of bearings was measured. The relationship between temperature of bearings and continuous rotating time was explored. The curves of the friction coefficient varying with the continuous rotating time were measured. The results show that the dry friction coefficient is 0.038~0.061 when the load-carrying capacity of braided PTFE spherical bearings is 25~135 MPa. The mechanism of bearings' failure was analyzed by means of scanning electron microscopy. The PTFE of the braided composite is extruded in the process of the wear test. The self-lubricating function of spherical bearings is going down. The base of the braided composite is worn away.