If the grease is unsuitable at low temperature soft, it is good.Needle bearing sound description The sound quality does not change with the rotation speed (dust/foreign matter) The sound quality changes with the rotation speed (scratch) Dust/Foreign Objects Rough surface of raceway, balls, rollers Surface of raceway, balls, and rollers scratches Small bearings Rough surface of raceway, ball and roller Intermittently and regularly Contact with the seal ring Contact with the retainer and seal cover Due to the change of the slewing speed, the size and height are changed. There are also times when it is similar to the alarm or flute. Large metal impact sound 　　

Low-speed thin-walled large bearings (TTB), etc. Operation is due to the internal wear of the retainer, insufficient lubrication, and insufficient bearing load.. Lubricating oil is too thick, radial internal clearance is too large, lubricating oil is insufficient The bite sound between metals sharp sound The rollers and ribs of the roller bearing are bitten. After replenishing lubricating oil, it will stop temporarily. The internal clearance is too small. The abnormal sound disappears after reducing the internal gap or preloading. The raceway, roller, and ball are deformed due to friction. More obvious at low speed 　　

Continuous sound at high speed The impact China Clutch Release Bearing factory sound inside the retainer, insufficient lubrication. Excessive sound pressure The surface of the raceway, roller, and ball is rough. The internal clearance is too large due to friction. Insufficient lubricating oil Irregular sounds from small bearings Bubble burst sound in lubricating oil Slippage of the fitting part Squeaking of the mounting surface Squeaking of keys, etc. Resonance, poor fit (poor shaft shape) Track surface deformation Track surface, balls, roller ripples (large bearings, if there is a slight tone, it is normal) Feel when rotating manually Track surface scratches (regular) Balls, roller scratches (irregular) Dust/foreign objects, track surface deformation (partial clearance is negative) Large bearing 　

Continuous noise occurs at high speed Small bearing Track surface, ball, roller surface scratches Stop instantly when power is cut off Motor electromagnetic sound Irregularity (non-rotating speed changes and changes), 　　 mainly small bearings Mixed with dust/foreign objects Tapered roller bearings 　Regular and high-speed continuous sound Large bearings Small bearings It is normal if the sound of the retainer is clear. In the case of all rollers, impact noise between the rollers will occur. With a certain speed, the sound becomes louder. Rotating body tearing sound, orbit wheel deformation, squeaking The main reason is that the cylindrical roller bearing changes due to the change of the rotation speed, and the metal sound can be heard when the sound is loud