The motor is widely used, due to the power size, installation type, protection grade, load type and connection method is different, the selection of bearings is also very different, only the correct selection of bearing type, so that it can adapt to the operating requirements of the equipment, in order to reduce the occurrence of bearing failure. The following is an explanation of the selection and installation of bearings in the motor assembly process for reference. 
1)Special high-quality bearings are usually selected for the motor, and sealed bearings are preferred for small motors with frame number H160 and H160 and below, and cold-pressing is used for assembly. H180 and above the motor uses open bearings, and the outer small cover processing oil injection and drainage holes, easy to maintain the oil, to ensure the life of the bearing.
2)For large frame number (H315 and above) motor, the bearing type should be considered when selecting the bearing axial position change caused by the thermal expansion of the motor shaft, usually choose one end as the positioning end, the other end as the swimming end, the swimming end is preferred to choose the column bearing; In addition, during the operation of the motor, the driving end bearing must bear both the output torque of the motor and the reverse torque of the working machine, resulting in the driving end bearing bearing bearing greater working force than the non-driving end bearing, which is easy to wear. Therefore, in the manufacturing process, the driving end of the horizontal motor with large frame size selects column bearings with strong bearing capacity.
3) When the temperature of the shaft is high when the motor is working, especially the motor with protection grade IP55 and IP56, the large-clearance bearing is preferred.
4)Vertical motor due to the axial force of the rotor itself when working, especially the large frame number (H315 and above) motor, the axial load is larger, generally according to the frame number, H280 and below the frame number vertical motor, both ends of the use of large backlash deep groove ball bearings, H280 above the frame number vertical motor at the lower end of the use of angular contact thrust ball bearings, The upper end of the ball bearing with large clearance deep groove.
The basic indexes of bearing grease are: needle penetration, drop point, oxidation stability and low temperature performance. The choice of rolling bearing grease mainly considers the operating conditions of the bearing, such as the use environment (wet or dry), working temperature and motor speed. When selecting the grease according to the bearing load, the grease with small needle penetration should be selected for the heavy load. When working under high pressure, in addition to small penetration, it also has high oil film strength and extrusion resistance. The role of grease in bearing lubrication is mainly:
1)Form an oil film on the surface of the rolling body, separate the rolling body from the rolling track, reduce the friction and wear of the contact surface, and extend the fatigue life of the bearing.
2)Outside the bearing, the grease that does not participate in the lubrication of the bearing can prevent foreign bodies such as external dust from entering the inside of the bearing, and play a certain role in sealing and dust-proof.
3) The use of grease with good water resistance can prevent the occurrence of paint rust and prevent bearing rust.
Post time: Jul-08-2024
