Electric motor bearings are specialized support components designed for electric motors; their specifications-covering structure, dimensions, type, and precision-are governed by the GB/T 272-93 standard. These bearings utilize metal balls or rollers to minimize friction while supporting the rotation of the motor shaft. Common types include rolling bearings, sliding bearings, spherical plain bearings, and oil-impregnated bearings; rolling bearings are widely adopted due to their high load-bearing capacity, with deep-groove ball bearings being particularly prevalent in automotive drive motors thanks to their high mechanical efficiency. In the new energy vehicle sector, drive motor bearings must meet stringent requirements regarding high rotational speeds, high precision, low noise, and high-temperature resistance.
Small and medium-sized motors typically employ rolling bearings; for instance, deep-groove ball bearing models such as 6002-ZZ and 6003-2RS are commonly used in household electric vehicles [12]. Deep-groove ball bearings are frequently installed at both ends of small motors, whereas medium-sized motors often feature roller bearings at the load end. Bearings are categorized by lubrication method (grease vs. oil) and structural design (sealed vs. open); compatible models include specialized types such as QABP variable-frequency motors, M2QA-H marine motors, and the Y2 series. Installation requires press-fitting or thermal fitting techniques-such as heating the bearing to 80–100°C prior to assembly-along with strict adherence to procedures for cleaning, dimensional verification, and rust prevention. For aluminum-cased motors, differences in thermal expansion coefficients necessitate tighter fits in the bearing housing or the use of O-rings to prevent bearing creep. Grease selection should favor mineral oil-based products applied in standard quantities; low-viscosity, low-noise greases may be chosen to minimize operational noise.
Bearing selection involves a comprehensive evaluation of parameters such as boundary dimensions, material tolerances, operating temperatures, and load spectra, with service life calculated based on rotational speed [3]. Common malfunctions include overheating and abnormal noise, necessitating regular inspection and maintenance.
