S48C钢某型回转支承寿命试验研究

Life Test Study on a Certain Type of Slewing Bearing Made of S48C Steel

摘要: 通过对QND1XXX.XX型号回转支承进行台架寿命试验，评估其在特定载荷谱下的疲劳寿命和失效模式，为产品设计和工程应用提供数据支持。以材质为S48C的回转支承为对象，在4 r/min转速下，施加轴向载荷270 kN、倾覆力矩346 kN·m进行动态循环测试，并定期在静载条件下测量滚道磨损量。结果显示在10万转试验结束后，内圈受力最大点出现一处约1 mm × 2 mm的压溃；外圈滚道出现整圈压痕，并在堵塞孔旁滚道位置出现一处约1 mm × 1 mm的压溃；堵头滚道面出现磨损，钢球与隔离块状态完好。总成径向间隙由初始的0.13 mm增大至0.22 mm，增大量为0.09 mm。静载条件下，滚道合成磨损量由初始的0.48 mm增加至0.66 mm，总磨损量为0.20 mm。该型号回转支承在给定试验条件下完成10万转寿命试验，未出现影响运转的严重失效，但滚道已出现早期疲劳压溃迹象。径向间隙和滚道磨损量的变化趋势表明，其主要失效模式为接触疲劳磨损。

Abstract: Through bench life testing of the QND1XXX.XX slewing bearing, this study evaluates its fatigue life and failure modes under specific load spectra, providing data support for product design and engineering applications. Using a slewing bearing made of S48C material as the test subject, dynamic cyclic testing was conducted at a rotational speed of 4 r/min under an axial load of 270kN and an overturning moment of 346kN·m. Wear measurements on the raceway were periodically taken under static load conditions. Results showed that after 100,000 revolutions, a crush area of approximately 1 mm × 2 mm appeared at the maximum stress point on the inner ring. The outer ring raceway exhibited full-circumference indentations, with an additional crush area of about 1 mm × 1 mm near the plug hole. Wear was observed on the plug raceway surface, while the balls and separator blocks remained intact. The assembly’s radial clearance increased from an initial 0.13 mm to 0.22 mm, representing an increase of 0.09 mm. Under static load conditions, the combined raceway wear increased from an initial 0.48 mm to 0.66 mm, with a total wear of 0.20 mm. This slewing bearing model completed a 100,000-revolution endurance test under specified conditions without severe failures affecting operation. However, early signs of fatigue crushing appeared on the raceway. The trends in radial clearance and raceway wear indicate that the primary failure mode is contact fatigue wear.