Jinan Boyu Bearing Co.,Ltd.

Sound

Features

Causes

Hiss

Small bearings

Raceway, ball or roller surfaces are rough.

Buzz to Roar

Loudness and pitch change with speed.

Resonation
Poor fit (Poor shaft shape)
Bearing rings deformed.
Vibration of raceways, balls, or rollers (For large bearings, if this sound is minor, then this is considered normal).
Brinelling

Crunch

Felt when the bearing is rotated by hand.

Scoring of raceway surface (regular).
Scoring of balls or rollers (irregular).
Dust/Contamination
Deformed bearing ring (partial interference clearance).

Hum

Disappears when power supply is switched off.

Electromagnetic sound of motor.

Chatter

Noticeable at low speeds.
Continuous at high speeds.

Bumping in cage pockets (insufficient lubricant) --eliminated by clearance reduction or pre-loading.
Rollers bumping into each other on full-roller bearing.

Clang/Clatter

Metallic, loud bumping sound.
Thin section large bearing (TTB) at low speeds.

Bearing ring deformed.
Grating of key.

Screech/Howl

Occurs mainly on cylindrical roller bearings.
Sound changes with speed.
Loud metallic sound that disappears temporarily
when grease is added.

Large radial clearance.
Poor lubrication/grease consistancy.

Squeak

Metal-to-metal spalling sound.
High pitch

Spalling of roller and rib of roller bearing.
Small clearance
Poor lubrication

Squeal

Generated irregularly due to grating.

Slip on fitting surfaces.
Grating on mounting seat, of key, etc.

Faint tinkle

Irregular (not changing with speed).
Primarily on small bearings.

Dust in bearing.

Rustle

Sound quality remains the same even if speed changes (Dirt).
Sound quality changes with speed (Scoring).

Dirt
Raceway, ball, or roller surfaces are rough.

Rustle

Generated intermittently at regular intervals.

Chafing at the labyrinth.
Contact of cage and seal.

Rustle patter

Regular and continuous at high speed.

Generated by retainer.
Normal if sound is clear.
Grease is inadequate if sound is generated at low temperatures (Use soft grease).
Wear of cage pockets.
Insufficient lubricant.
Low bearing load.

Growl

Continuous at high speeds.

Scoring on raceway, balls, or rollers.

Quiet Fizzing/Popping

Generated irregularly on small bearings.

Bursting sound of bubbles in grease.

Large Sound Pressure

Large Sound Pressure

Rough raceway, roller, or ball surfaces.
Raceway, rollers, or balls are deformed by wear.
Large clearance due to wear.