Bearings are a vital part of any machinery and the correct choice of bearing configuration is essential for optimal operation and smooth running. This selection should be based on the machinery’s design parameters, the environment in which it is operating, the type of load, the precision requirements and other application factors.
This article will give an analysis of the various bearing configurations considered when selecting the most appropriate system for any machinery. Areas of discussion include;
1. Single Row Bearing Configurations.
2. Double Row Bearing Configurations.
3. Angular Contact Bearings.
4. Single Direction Thrust Bearings.
5. Multi Direction Thrust Bearings.
6. Cylindrical Roller Bearings
7. Tapered Roller Bearings.
8. Spherical Roller Bearings.
1. Single Row Bearing Configurations
These bearings come in two basic configurations; radial bearings and thrust bearings. Radial bearings support radial loads, and thrust bearings support axial loads. Radial bearings can also be divided into ball, cylindrical and tapered roller bearings.
Ball bearings, which are the most common type of bearing, can be identified by having two rings, one inner and one outer, which contain and support the balls. Depending on the application, some ball bearings are available with tight or loose tolerance and are often lubricated with grease.
Cylindrical roller bearings are composed of rows of cylindrical rollers, called elements, held together in a ring by an outer and inner ring. As the outer ring is rotated, the elements move relative to the rings and cause frictional forces which move the element relative to each other and result in stability and increased load capacity.
Tapered roller bearings consist of an inner race and an outer race, with two or more tapered rollers between them. As the rollers move relative to each other, the bearing can carry both radial and thrust loads. Tapered roller bearings are commonly used in automotive, agricultural, and industrial applications.
2. Double Row Bearing Configurations
Double row bearings are used in a wide range of applications where a greater load carrying capacity is required. As their name implies, double row bearings consist of two rows of rolling elements, typically balls, and are held together in an outer and inner ring. The configuration of the two rows allows for greater load capacity and better load distribution, making them a good choice for applications where heavy load handling is needed.
Double row bearings can also be supplied with different levels of precision depending on the application. For applications that require very strict tolerances, double rows of tightly-toleranced balls are used which offers the highest precision. For more general applications, double row bearings with loose tolerances are available.
3. Angular Contact Bearings
Angular contact bearings, which consist of two angularly-spaced rings, are used for applications where radial and axial loads need to be supported simultaneously. The angular contact of the rings provides greater load capacity and stability than a single row bearing.
Angular contact bearings are available in both single direction and double direction designs. Single direction angular contact bearings consist of two rings with one ring slightly larger than the other. This allows for one direction of load, in one radial plane.
Double direction angular contact bearings, on the other hand, are constructed with two rings of equal size, which allows them to handle loads in both directions. Double direction angular contact bearings are commonly used in applications such as gearboxes, electric motors and pumps.
4. Single Direction Thrust Bearings
Single direction thrust bearings are used in applications where components need to be able to support in one direction of thrust only. They have several components, including a thrust collar, needle rollers, outer and inner rings, and a retainer.
Single direction thrust bearings are commonly used in automotive transmission and suspension components, industrial machinery, and in low speed machinery such as gearboxes. They can also be used in high speed machinery such as pumps, turbines and electric motors.
5. Multi Direction Thrust Bearings
Multi direction thrust bearings are designed to support both radial and axial loads in multiple orientations. They consist of a thrust collar, needle rollers, an outer and inner ring, and a retainer.
Multi direction thrust bearings provide less frictional resistance than single direction thrust bearings and are often used in high speed machines such as jets, helicopters and turbines. Although multi direction thrust bearings offer higher load capacity than single direction thrust bearings, they have a more complex structure which can increase the cost of manufacture.
6. Cylindrical Roller Bearings
Cylindrical roller bearings are used to withstand heavy radial and axial loads. They are composed of an inner race, an outer race, and several rows of cylindrical rollers held together by an inner and outer ring.
The rows of rollers enable the bearing to support heavier loads, while providing less friction and power consumption than ball bearings. As the outer race is rotated, the rollers move relative to each other, creating friction which helps to reduce sliding and maintain stability.
Cylindrical roller bearings are commonly used in applications such as industrial machinery, shipbuilding, machine tools, and conveyor systems.
7. Tapered Roller Bearings
Tapered roller bearings are designed to carry both radial and axial loads. They consist of several tapered rollers held together by an outer and inner ring. As the outer ring is rotated, the tapered rollers move relative to each other, creating friction which helps to reduce slipping and maintain stability. Tapered roller bearings are commonly used in automotive, agricultural and industrial applications.
8. Spherical Roller Bearings
Spherical roller bearings are used in applications where the load is primarily in a single direction, such as in conveyor systems. They consist of an inner race, an outer race and multiple spherical rollers held together by an inner and outer ring.
As the outer ring is rotated, the spherical rollers move relative to each other, creating friction which helps to reduce slipping and maintain stability. Spherical roller bearings are also able to compensate for misalignments between the shaft and housing, and are ideal for applications with high levels of vibration and shock loads.
In conclusion, a wide range of bearing configurations are available for selection who the machinery’s design parameters, operating environment, type of load, precision requirements and other application factors are taken into consideration. Depending on the application, different types of bearing configuration should be chosen for the best performance and efficiency.
