The rotation speed of the motor bearing is mainly limited by the temperature rise caused by the friction heating inside the bearing model. When the rotation speed exceeds a certain limit, the bearing will not continue to rotate due to burns, etc. The limit rotation speed of the bearing is the limit value of the rotation speed that does not generate frictional heat that causes burns and can rotate continuously. Therefore, the limiting speed of the bearing depends on the type, size and accuracy of the bearing, as well as various factors such as the lubrication method, the quality and quantity of the lubricant, the material and type of the cage, and the load conditions. The limit speeds of various bearings under grease lubrication and oil lubrication (oil bath lubrication) are listed in the dimension table of each bearing respectively. ) is the limit value of the rotational speed during rotation. Correction of limit speed: when the load condition C/P<13 (that is, the equivalent dynamic load P exceeds about 8% of the basic dynamic load rating C), or the axial load in the combined load exceeds 25% of the radial load, it should be Use formula (1) to correct the limit speed. nau003df1f2n(1) Limit after correction, rpm Correction factor related to load conditions (Fig. 1) Correction factor related to combined load (Fig. 2) Limit speed under normal load conditions, rpm (refer to bearing dimension table) Basic Rated dynamic load, N{kgf} equivalent dynamic load, N{kgf} radial load, N{kgf} axial load, N{kgf} pole motor and high-speed rotation Notes: The bearing rotates at high speed, especially when the speed is close to or When it exceeds 70% of the limit speed recorded in the dimension table, the following items should be paid attention to: (1) Use a bearing with high precision (2) Analyze the internal clearance of the bearing (considering the reduction in the internal clearance of the bearing due to temperature rise) (3) Analyze the material type of the cage (4) analyze the lubrication method.