The application of Ball bearings used in compressors and their Characteristics

Nov 27, 2023

The compressor is a machine that increases the pressure of gas, which is vital to the refrigeration system. It works by sucking in low-pressure and low-temperature refrigerant gas from the suction pipe and compressing it through the operation of the motor. The piston is driven to compress the gas, which is then discharged to the exhaust pipe as high-pressure and high-temperature refrigerant gas, providing power for the refrigeration cycle. There are different types of compressors, such as piston compressors, screw compressors, centrifugal compressors, and linear compressors.

The ball bearing used in the compressor is an essential mechanical component to support and guide the high-speed rotation inside the compressor.

Characteristics

Compressor ball bearings have the following features:

High-speed performance: Compressor ball bearings can withstand high-speed rotation and have good limit speed performance.

High-temperature resistance: It can work stably in high-temperature environments and is suitable for compressors in high-temperature environments.

Corrosion resistance: It can resist corrosion from acidic or alkaline media and is suitable for the chemical industry and other fields.

Long life: It has a long service life, reducing the frequency of maintenance and replacement.

Lower friction coefficient: It has a lower friction coefficient, reducing energy consumption and mechanical wear.

Structure

Compressor ball bearings mainly consist of the following parts:

Inner ring: The inner circle is a significant part of the bearing. It cooperates with the shaft and rotates together.

Outer ring: The outer ring is another essential bearing part. It matches and is fixed with the bearing seat.

Rolling element: The rolling element is the core part of the bearing. It is usually composed of high-hardness steel balls or ceramic balls.

Cage: The function of the cage is to maintain the position of the rolling elements and prevent them from contacting each other.

Compressor ball bearings mainly include the following types:

Deep groove ball bearings: The raceway width of this bearing is similar to the ball diameter, can support axial and radial loads, and is suitable for high-speed operation. Deep groove ball bearings can be obtained in sealed designs for specific applications.

Aligning ball bearings: Ball bearings can automatically adjust for shaft or shell misalignment and withstand various loads. This bearing is widely used in woodworking machinery, textile machinery drive shafts, vertical seated self-aligning bearings, and other fields.

Four-point contact ball bearings: Four-point contact ball bearings are used as thrust bearings on compressors. They mainly bear large axial loads and small radial loads in two directions. The inner ring of this kind of bearing is split, which can accommodate more rolling elements and improve the radial load-bearing capacity of the bearing. At the same time, its machined cage ensures that the bearing has small axial clearance and precise radial guidance capabilities during high-speed transfer operations. This compact bearing design does not require separate positioning bearings.

Thrust ball bearing: This bearing is mainly used in compressors as a thrust bearing. It does not need to take the radial load and can carry a sizeable axial load in both directions.

Materials

Commonly used materials for compressor ball bearings include:

High carbon chromium bearing steel: This is a widely used bearing material with reasonable wear and fatigue resistance.

Stainless steel: Stainless steel is suitable for corrosive environments and has good corrosion resistance.

Ceramic material: It has the advantages of high hardness, low density, high-temperature resistance, etc., and is suitable for high-speed rotating compressors.

Manufacturing process

The manufacturing process of compressor ball bearings mainly includes the following steps:

Forging: Forging steel at high temperatures to form a basic shape.

Turning: Turn the forged steel to achieve the required accuracy.

Heat treatment: Heat treat the turned steel to improve its hardness and wear resistance.

Grinding: Grind the heat-treated steel for accuracy and surface quality.

Assembly: Assemble rolling elements, cages, and other parts of the inner and outer rings.

Testing: Test the assembled bearings to meet relevant standards.

Application areas

Compressor ball bearings are widely used in the following fields:

Chemical industry: In the chemical industry, compressor ball bearings are used for gas compression and transportation in various chemical equipment.

Refrigeration industry: In the refrigeration industry, compressor ball bearings are used for gas compression and circulation of refrigerators.

Electric power industry: Compressor ball bearings are used in various power generation equipment and air compression systems in the electric power industry.

Automotive industry: In the automotive sector, compressor ball bearings are used for gas compression in automotive air conditioning and braking systems.

Other fields: In addition to the above areas, compressor ball bearings are widely used in various machinery and equipment, such as compressors, blowers, pumps, etc.