关节轴承中微凸体的热分析

Thermal analysis of asperity in spherical plain bearing

摘要:

为研究关节轴承内外圈摩擦副上微凸体在相对滑动过程中的摩擦热问题,建立半球状微凸体相对光滑平面滑动的模型,对点热源导致的温升进行积分,计算关节轴承内外圈在微凸体接触面处的稳态温升分布. 分别计算微凸体在弹性接触与塑性接触状态下接触面的稳态温升分布,并研究了在不同角速度和载荷下接触面沿速度方向的温升变化. 给定在一定范围内变化的载荷及速度,分别计算绘制出了两种不同型号关节轴承中的微凸体在接触区的最大闪温图. 计算结果表明:内圈微凸体在接触区的温升是对称分布的,最大温升位于接触面的中心点,外圈接触区后沿的温升大于前沿的温升,最大温升出现在中心点偏后沿的位置. 轴承角速度或微凸体载荷越大,接触区的温升越大. 在低速重载工况下,微凸体的最大闪温值较小；而在高速情况下,微凸体的最大闪温值较大. 关节轴承在工作时应注意载荷和角速度的控制,防止因微凸体摩擦生热过多从而造成轴承使用性能受损.

Abstract:

To study the frictional heat of the asperity on friction pair of the inner and outer rings of spherical plain bearing during relative sliding process, the model of a hemispherical asperity sliding relative to a smooth plane is established. The steady-state temperature rise of the inner and outer rings in the asperity contact zone is calculated with integrating the temperature rise caused by point heat source. The temperature rise distributions of the contact zone under elastic contact and plastic contact were calculated respectively, and then the temperature rise along the velocity direction under different angular velocities and loads was examined. The maps of the maximum flash temperature in the contact zone of two different types of spherical plain bearings are presented. The results show that the temperature rise of the asperity in contact zone is symmetrically distributed, and the maximum temperature rise is at the center point. The temperature rise at the trailing edge of the outer ring is greater than that at the leading edge, and the maximum temperature rise appears at the position of trailing edge. The higher the angular velocity or load, the higher the temperature rise. Under low-speed and heavy-load conditions, the maximum flash temperature of the asperity is low, and in case of high-speed conditions, the maximum flash temperature is high. To prevent the spherical plain bearing from being damaged due to excessive heat generation caused by asperities, the control of loads and angular velocities should be noticed.