Bearings

 Bearing is a device which permits a definite relative moving between two or more parts, this moving may be rotational or linear. The bearings can be classified upon their permitted moving, upon their work fundamentals and also upon load tolerance.

Have you ever surprised by attention to operation of some devices such as skate’s wheels or electrical engines which rotate smoothly and fast? The reason is bearing. The bearing may be at any devices that we use every day. Without bearings, all parts which may be affected by friction should be changed continuously.

Primary Concepts:

The concepts relevant to bearings are simple; your car’s wheels operate as a big bearing. If you use a device such as skate instead of wheels, your car cannot come down from a slope to the road easily. Because when the objects slip, the friction between them will make a power which desired to minimize that object’s speed, but if two surfaces can roll over each other, the friction minimized significantly. A simple bearing is like something that can be found in skate’s wheel. The bearings minimize the friction through interior and external steel layer and also by roller or smooth steel balls which rotate relatively. These rollers or balls by tolerating the applied load help to device that the device rotates smoothly.

Bearings Loading:

In general, they are loading in two ways, radial force and axial force and in accordance with applied place of bearings; all the loads may be axial, radial or a combination of both.

The bearings which connected to the engine and pulley shaft are affected by radial loads. In above photo, the applied bearings in electrical engine and pulley only are affected by radial loads. More loads will be made by tensile force of connecting belt in pulley.

The applied bearing in this chair is affected by axial load.

The showed bearings in above picture operate like applied bearings in support. These bearings affected by pure axial forces, and all loads resulted by weight of the person who has sat on the chair.

The applied bearings in a car’s wheel are affected by both radial and axial loads.

The above mentioned bearings are operated as same as bearings which are in the ring of your car’s wheel. These bearings tolerate both radial and axial loads. The radial load caused by car’s weight and axial load caused by lateral forces during moving in road’s turns.

Bearing Types:

There are different types of bearings which applied for a specific purpose. Some of them are:

-         Ball bearing

-         Roll bearing

-         Ball-linear bearing

-         Ball-axial bearing

-         Axial roll bearing

-         Conical-roll bearing