Deep Groove Ball Bearings: Structural Features and Precautions in Use

1. What is a deep groove ball bearing? Why is it so widely used?

Deep groove ball bearings are the most common type of rolling bearings. They have a simple structure and a wide range of uses. They have the following core features:

Structural design: It consists of inner and outer ring steel balls and a cage. The inner and outer rings have deep groove raceways and can withstand radial and axial bidirectional loads.

Performance advantages: small friction coefficient (0.0010~0.0015) high speed (limit speed can reach more than 20000rpm) low manufacturing cost.

Application scenarios: From household appliances (such as washing machine motors) to industrial equipment (motor gearboxes and automobile wheels), covering more than 80% of bearing usage needs.

2. Six precautions in use

Installation specifications

Cold installation method: Use a special sleeve to evenly knock the inner ring of the bearing (do not knock the outer ring directly). It is recommended to heat the interference fit to 80~120℃ for hot installation.

Alignment requirements: The eccentricity between the shaft and the bearing seat must be less than 0.05mm, otherwise it will cause early fatigue peeling.

Lubrication management

Grease selection: low viscosity grease (such as Mobil Polyrex EM) for high speed, and composite calcium sulfonate grease for high temperature conditions.

Replenishment cycle: For every 15℃ increase in operating temperature, the lubrication cycle is shortened by half (for example, grease needs to be replenished every 2000 hours at 70℃).

Load control

Radial load: must not exceed the basic rated dynamic load Cr (such as 6208 bearing Cr=29.1kN).

Axial load: must not exceed 20% of the radial load, otherwise angular contact bearings need to be used instead.

Operation monitoring

Abnormal vibration: when the acceleration value is greater than 10m/s², the machine needs to be stopped for inspection.

Temperature rise warning: the ambient temperature of +40℃ is the normal threshold, and lubrication or alignment problems need to be checked if it exceeds.

Disassembly points

Special tools: when using a puller for disassembly, the inner and outer rings need to be tightened synchronously to avoid deformation of the cage.

Scrap standard: Replacement is required when pitting (diameter > 1mm) or clearance increases to 3 times the initial value.

Storage conditions

Rust prevention measures: Relative humidity < 65%, 3 years shelf life for sealed packaging.

Stacking requirements: Store flat, no more than 5 layers, to avoid deformation of the outer ring.

3. Typical faults and solutions