Industrial Bearings

A bearing is a device that allows controlled relative motion between two parts. It is a component used to decrease the friction, which can be caused by any elements in motion, in order to reach its maximum efficiency, by eliminating the torque being converted into heat. So bearings help in decreasing the losses caused by conversion into heat, and increasing the efficiency of the machine or item.

Bearings can be broadly divided into two types depending on the purpose they are used for:  linear bearings and rotational bearings.

Linear Bearings: These bearings are used to obtain a smooth motion in a straight line. Drawers are a good example of this where the bearings help the drawer to be pulled out or pushed in a straight line, with relative ease.
Rotary Bearings: These facilitate an object to move around a central point. Wheel rotation on a shaft is a common example of the use of rotary bearings.

Bearings provide the following advantages in mechanical action:
1  Low Friction, especially the starting friction.
2  The ability to support both radial and thrust load, and high speeds of rotation.
3  Accurate performance under changing loads and speed.
4  High load carrying capacity.
5  Operating ability under extreme conditions of speed and performance.
6  Practically no wear in running.
7  Simple methods of lubrication.
8  Inherently precision mechanisms.

Uniformity in the manufacturing process is a crucial factor to ensure consistent performance by bearings. If variation occurs in the manufacturing process from part to part, they are tweaked to withstand a wider range of stresses, heat, etc.
This can in turn lead to variations in the performance of each bearing, either individually, or from lot to lot. The narrower the variation, the greater is the consistency of each bearing’s performance.

One of the most important things is selecting the correct bearing for a particular machine. The selection of ball and bearings for a given installation depends upon the following factors:
1  The load carrying capacity.
2  The speed of the shaft in rpm.
3  The type of service required from it.
4  The required life of the bearing.
5  The proportion of thrust to radial load.

Rotary bearings constructed out of ceramic are called ceramic bearings.  Ceramic hybrid bearings is the most common type of ceramic bearing, and have inner and outer rings made out of steel, but the balls made out of ceramic.  The most common types of ceramic bearings are angular contact and conrad.  Ceramic bearings are better than steel bearings in various ways. Ceramic bearings give increased stiffness, higher speed and acceleration capability, , higher accuracy, reduced lubrication requirements, lower friction and heat generation, low thermal expansion, and extended operation life. Bearings containing all ceramic balls are not advantageous and are generally not used, except in electric motor applications.

Pillow block bearings are a form of mounted bearing and are used to provide load support to a rotating shaft. The bearing housing is mounted on a surface parallel to the shaft axis. Elongated boltholes at the base of the unit allow for some adjustment and easy mounting of the pillow block bearing.