Precautions for backing bearings in high-speed rotation

Backing bearings in high-speed rotation, especially when the speed is close to or exceeds the limit speed recorded in the dimension table,the following matters shall be paid attention to:
1. Use precision bearings
2. Analyze the bearing internal clearance (considering the reduction of bearing internal clearance caused by temperature rise)
3. Analyze the material type of cage (for high-speed rotation, copper alloy or phenolic resin is suitable for cutting cage. In addition, synthetic resin molding cage suitable for high-speed rotation is also available)
4. Analyze the friction coefficient (Reference) of bearing in lubrication mode (circulating lubrication, jet lubrication, oil mist lubrication and oil-gas lubrication suitable for high-speed rotation) for comparison with sliding bearing, the friction torque of rolling bearing can be calculated according to the bearing inner diameter by the following formula: M = UPD / 2, where M: friction torque, Mn. M {KGF. Mm} U: friction coefficient, bearing load, n {KGF} d: The nominal inner diameter of bearing, mm, friction coefficient u are greatly affected by bearing type, bearing load, rotating speed, lubrication mode, etc.

The speed of backing bearing is mainly limited by the temperature rise caused by friction and heating inside the bearing. When the speed exceeds a certain limit, the bearing will not continue to rotate due to burns, etc. The limit speed of bearing refers to the limit value of continuous rotation without friction and heating causing burns.

Therefore, the limit speed of bearing depends on the type, size and accuracy of bearing, lubrication mode, quality and quantity of lubricant, material and type of cage, load conditions and other factors. The limit speed of various bearings when grease lubrication and oil lubrication (oil bath lubrication) are respectively contained in the size table of each bearing, and its value represents the limit value of speed when the standard designed bearing rotates under general load conditions (C / P > = 13, FA / FR < = about 0.25). In addition, the lubricant may be superior to other properties according to its type and brand, but it is not suitable for high-speed rotation.