The Difference Between Ball Bearing And Roller Bearing

Ball bearing

A ball bearing is a mechanical part that uses the rolling of balls (usually spherical steel balls) to reduce friction and support the rotating shaft. It usually consists of inner and outer rings, balls, cages and sealing devices.

According to the bearing ring configuration, ball bearings are divided into deep groove type and angular contact type.

Ball bearings can also be divided into radial bearings and thrust bearings according to the direction of applied load, among which radial bearings bear radial loads and thrust bearings bear axial loads.

During the rotation of ball bearings, the contact between the balls and the inner and outer rings is “point” contact, so it has higher rotation accuracy and less friction resistance.

Roller bearing

Roller bearings are a type of rolling bearings that rely on rolling contact between the main components to support rotating parts. Its rolling elements (rollers) can be cylindrical, needle-shaped, conical or spherical, etc.

According to the shape of the rollers, roller bearings are divided into cylindrical roller bearings, needle roller bearings, tapered roller bearings and spherical roller bearings, etc.

Roller bearings can also be divided into single row, double row or four row according to the number of rolling element rows.

The contact between the rolling elements and the inner and outer rings of the roller bearing is “line” contact, which theoretically has higher load-bearing capacity and smaller deformation.

The Difference Between Ball Bearing And Roller Bearing

Structure and composition:

• Ball bearings:

Mainly composed of outer ring, inner ring, ball, retainer and seal ring. Ball is the rolling element in the bearing, which supports the bearing and axial load through point contact.

• Roller bearings:

Also composed of outer ring, inner ring, rolling element (roller), retainer and seal ring. However, the rolling element of the roller bearing is the roller. Unlike the point contact of the ball bearing, the roller bearing realizes line contact.

Load-bearing capacity and speed:

• Ball bearings:

Due to the small size of the ball, the load-bearing capacity is relatively limited, which is more suitable for high-speed and light-loaded machinery and equipment. When rotating at high speed, the friction loss is small and the noise is low.

• Roller bearings:

The roller size is larger, so the load-bearing capacity is better, especially for low-speed and high-load machinery and equipment. However, roller bearings have large friction losses and cannot be used for high-speed rotation, otherwise it will lead to increased noise and shortened service life.

Application areas:

• Ball bearings:

Because of their simple structure, low manufacturing cost, long service life, and ability to withstand high axial and radial loads, they are suitable for various high-speed and low-load bearing applications, such as power tools, automobile engines, aircraft engines, home appliances, construction machinery, light machinery, etc.

• Roller bearings:

Suitable for various low-speed and high-load bearing applications, such as heavy machinery, cranes, steel metallurgy, mining machinery, ships, etc.

Features:

• Ball bearings:

Small friction coefficient, small starting and running torque, small power loss, high efficiency. Small radial clearance and high rotation accuracy. Because it is a standardized component, it has good interchangeability and maintainability. However, under high speed and heavy load conditions, the service life will be reduced.

• Roller bearings:

The torque required for starting is small, the rotation accuracy is high, and it is easy to select. Compared with the point contact of ball bearings, the rollers of roller bearings are in line contact, which is easy to withstand heavy loads and impacts.

There are obvious differences between ball bearings and roller bearings in terms of structure, load-bearing capacity, speed, application areas and characteristics.

When choosing a bearing, you should consider various factors comprehensively according to the specific working conditions and requirements and choose the most suitable bearing type.