EXPERIMENTAL RESEARCH ON THE LUBRICATION COOLING PERFORMANCE AND DURABILITY OF HIGH-SPEED BEARINGS UNDER AXIAL OVERLOAD CONDITIONS

Aero-engine spindle bearings operate under extreme operating conditions, including high temperatures, high speeds, and heavy loads. Thus, the reliability of the design is critical to ensuring optimum engine performance. In order to assess the reliability and safety of high-speed angular contact ball bearings for an aero-engine spindle subjected to axial force overload, tests are conducted using a certain type of aero-engine spindle bearing test rig. The spindle bearings are tested at the design operation speed of 17,000 rpm and an axial force of 25,000 N, as well as overload conditions with a reduced speed of 14,000 rpm and a maximum axial force of 58,000 N. The study analyzes the effects of different bearing inner race speeds, axial loads and lubricant temperatures and flow rates on bearing temperature control and vibration. The results indicate that an increase in inner ring rotation speed has a significant impact on the temperature rise rate of the bearing. Under the same lubricant temperature and flow rate conditions, an increase in axial load has a considerable effect on the temperature rise of the bearing. Increasing the flow rate of the lubricant can effectively reduce the temperature rise of the bearing and suppress its vibration to a certain extent under the same operating conditions. Furthermore, the durability of the bearing under a load spectrum that includes both design conditions and overload conditions is evaluated and the bearing damage is briefly analyzed, which provides a research idea for improving the service life of the bearing. The results indicate that appropriate lubricant temperature and flow conditions can effectively avoid the excessive temperature rise of the bearing under high contact stress and extend the operating duration of the bearing. This study can provide guidance and reference for the structural safety design and overload use of high-speed angular contact ball bearings.