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Ball Bearing & Roller Bearing

Updated: Oct 21, 2020

Bearings play an important role in mechanical equipment. Its main function is to support the rotating body of the machine, which can ensure the accuracy of rotation and reduce the friction coefficient generated by the movement of metal parts. Bearings contain tiny steel balls inside that allow for parts to roam around each other as opposed to against each other.

Bearings reduce stress to allow for greater energy efficiency and enable the prolonged existence of many day-to-day appliances. There are two main types of bearings which are ball bearing and roller bearing.


Ball bearing

Ball bearing is a rolling bearing. The ball is installed in the middle of the inner ring and the outer ring and it can bear a large load. Ball bearings are mainly composed of four basic elements includes balls, inner ring, outer ring, and retainer. It is often used to carry the load, reduce friction, and fix the moving parts. Ball bearings use balls to separate two rolling ways to reduce the friction on the moving surface.

1. Angular Contact Ball Bearing

Angular contact ball bearings can bear radial load and axial load at the same time because they have inner and outer ring rolling ways, which move relative to each other in the direction of the bearing axis. They can work at higher speeds. The contact angle is defined as the angle between the line connecting the contact point of the ball and the rolling way in the radial plane and the angle between the line perpendicular to the bearing axis, and the radial load is transmitted from a rolling way to another way.

2. Deep Groove Ball Bearing

Deep groove ball bearings have a wide range of uses. They apply continuous rolling ways to make it become the most appropriate for radial loads. Besides, it can also tolerate axial, radial, or composite loads. Even at high speeds, this design can achieve accuracy tolerances. It can be used to replace high-speed angular contact ball bearings.

3. Self-Aligning Ball Bearing

A self-aligning ball bearing is a bearing equipped with spherical balls between the inner ring of two rolling ways and the outer ring whose rolling way is spherical, and the center of curvature coincides with the bearing axis. Self-aligning ball bearings have two structures: cylindrical bore and tapered bore. Its characteristic is that the outer ring rolling way is spherical, with automatic alignment, which can compensate for errors caused by misalignment and shaft deflection.

4. Thrust Ball Bearing

Thrust bearing is a type of rotary bearing. Like other bearings, they allow rotation between parts, but they are designed to support the main axial load. They can bear axial load, but cannot bear radial load. Thrust bearings have two kinds of designs: single direction and double direction.


Roller Bearing

The design of roller bearing is mainly used to bear the load while minimizing friction. It uses cylindrical elements to transmit loads instead of balls so that the spacing between the moving parts of the bearing can be maintained. Although rolling bearings can withstand higher loads than ball bearings, they are very slow in operation. Most roller bearings have self-aligning function, it is easy to overcome misalignment and installation problems.

1. Cylindrical Roller Bearing

The inner part of the cylindrical roller bearing is formed by parallel arrangement of rollers. Spacers are mainly installed between the rollers, which can be used to prevent the rollers from inclination or the friction against each other. This can effectively prevent the increase in rotation torque. The length of cylindrical roller bearings is slightly larger than the diameter. Compared with ball bearings, it mainly bears the radial load, with large load capacity and large radial load capacity. Cylindrical roller bearings have low friction and are suitable for high-speed rotation. The bearing has a separable inner ring and outer ring structure. Most of them are used in electric motors and the oil & gas industry.

2. Needle Roller Bearing

Needle roller bearings are roller bearings with thin and long cylindrical rollers, which are called needle rollers. These rollers are used to reduce the surface friction caused by rotation. Compared with ball bearings, needle roller bearings have a large surface area in contact with the bearing rolling ways. The radial structure is relatively compact. When the inner diameter and load capacity of needle roller bearings are same with other categories of bearings, its outer diameter will be the smallest. It is very suitable to use on radial installation for those structures which is limited by the size dimensions. The needle roller bearing has a high load carrying capacity. Nonetheless this kind of bearing can only bear a radial load.

3. Spherical Roller Bearing

The spherical roller bearing itself have two rows of rollers, its outer ring has a common spherical rolling way, while its inner ring has two rolling ways that are inclined relative to the bearing axis. They are self-aligning because the center of curvature of the outer ring rolling way surface coincides with the bearing axis. Therefore, it is not susceptible to the influence of the angle between the shaft and the bearing housing on the error or shaft bending. Spherical roller bearings have various internal clearances and retainer options, which can withstand axial loads in any direction. They also have extremely high shock load resistance, but the maximum speed is lower.

4. Tapered Roller Bearing

Tapered roller bearings are a rolling element of a tapered roller radial thrust rolling bearing. This kind of bearing is mainly divided into single-row, double-row, and four-row tapered roller bearings according to the number of rows of rollers installed. Single-row tapered roller bearings can bear radial loads with axial loads in a single direction. When the bearing bears the radial load, it will produce axial component force, so it needs another bearing that can bear the axial force in the opposite direction to balance. Tapered roller bearings are usually used for heavy-duty applications that require durability.


The biggest difference between ball bearing and roller bearing is their contact surface. The contact surface of the ball bearing has only one point. Therefore, it limits the number of surfaces that the ball contacts with the rail. For roller bearing has an entire contact line. This improves the rigidity, stability, and maximum load capacity of the system.

There are many forms of bearings, and the bearing used varies depending on the purpose. Contact us now at +6011-7001 7687, you can find the bearing you need.

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