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24
2026
-
02
What factors need to be considered when selecting motor bearings?
First, evaluate the load and rotational speed; then determine the required precision and operating environment; finally, select the appropriate bearing design, lubrication, and insulation.
First, evaluate the load and rotational speed; then determine the required precision and operating environment; finally, select the appropriate bearing design, lubrication, and insulation.
Core Factors for Motor Bearing Selection (Simplified Version)
Load magnitude and direction
Pure radial → Deep groove ball bearings, cylindrical roller bearings
Radial + axial → Angular contact ball bearings, self-aligning roller bearings
Pure axial → Thrust bearing
Use roller bearings for heavy loads; use ball bearings for light loads at high speeds.
Rotational speed
The higher the rotational speed, the more emphasis should be placed on ball bearings, small size, and low friction.
Exceeding the maximum speed will cause overheating, bearing burnout, and a dramatic reduction in service life.
Rotational Accuracy and Stiffness
Servo motors, spindles, and machine tool motors → High-precision P4/P5-grade angular contact bearings
Ordinary fans and pumps → Standard class P0 is sufficient.
Axial Clearance and Thermal Expansion
The motor heats up and expands during operation → one end is fixed, the other end is free to move.
Common configuration: fixed-end NJ/NU cylindrical roller bearings + floating-end deep-groove ball bearings
Environmental conditions
Dust and moisture → Sealed type 2RS/ZZ
High temperature → High-temperature grease, metal cage
Corrosion → Stainless steel or special coating
Shaft Current (A Must-Read for Variable-Frequency Motors)
Inverter drive → Insulated bearings must be used.
Otherwise, electrical erosion, abnormal noise, and premature failure are highly likely to occur.
Noise and Vibration Requirements
Home appliances, silent motors → Low-noise deep groove ball bearings
Cage made of nylon for superior performance; silent design
Installation Space and Structure
Small space → Needle roller bearings, thin-wall bearings
Vertical motors → Axial load (thrust bearing) must be considered.
Lifespan and Reliability
Continuous operation, high reliability → Select 1–2 larger sizes or a reinforced model.
Calculate L10 life (standard engineering configuration)
Lubrication method
Grease Lubrication: General-Purpose, Maintenance-Free
Oil Lubrication: Ultra-High-Speed, High-Power Motors
Related Information
2026-02-23
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