Which aspects should be considered in the selection of rolling bearings?


There are many types and forms of rolling bearings and a wide range of sizes. In order to choose suitable bearings to achieve the purpose of design, it is necessary to comprehensively analyse the use conditions of machinery, the performance requirements of bearings, the specifications and parameters around the bearings to the market and economy.

Since the shaft diameter is generally determined first and then the bearing is selected, it is necessary to preliminarily determine the type of the bearing based on the inner diameter of the bearing and considering the installation space and configuration mode of the bearing. Secondly, analyse and compare the "bearing life required by machinery" and "bearing life calculated according to bearing load" to determine the size of the bearing; It is necessary to determine the internal structure of bearings such as accuracy level, internal clearance, cage, lubricant, etc.

The general steps selected are:

1. Determination of bearing type and configuration. ( The reference factors are: the installation space of the bearing; the load size, direction and nature of the bearing; the rotation speed; the rotation accuracy; the noise and friction torque; the rigidity; the relative tilt of the inner and outer rings; the installation and disassembly; the configuration of the bearing; the market and economy).

2. Determination of bearing size. ( Mechanical required bearing life; equivalent dynamic load; equivalent static load; rotational speed; main size of the bearing; basic rated dynamic load; basic rated static load; allowable axial load).

3. Determination of accuracy level. ( Rotation accuracy; noise and friction torque; rotational speed; bearing accuracy).

4. Cooperate with the internal clearance. ( The size and nature of the load; the temperature during operation; the material, size and accuracy of the shaft and the shell; the cooperation; the temperature difference between the inner ring and the outer ring; the speed; the preload; the bearing accuracy; the internal clearance of the bearing).

5. Material and type of retaining frame. ( Turning speed; noise).

6. Special environmental response measures. ( Medium conditions, such as temperature, seawater, vacuum, medicine, dust, gas, magnetic field, etc.; special materials; special heat treatment; special surface treatment; lubricant).

7. Lubrication method, lubricant and sealing device. ( Operating temperature; speed; lubrication mode; lubricant; sealing device; limit speed of bearing; grease life).

8. Installation and disassembly methods and installation-related dimensions.

9. Final determination of bearings and their peripheral specifications. Finally obtain bearings whose performance meets the requirements.