The part on which the shaft of a particular mechanism is supported is called a bearing. It must withstand a certain load over a long period of time. During operation, the bearing should not make noise and should not interfere with the rotation of the shaft. It is desirable that the bearing work without maintenance until the end of the operation of the unit or mechanism.
Each bearing has an outer and inner race, rollers or balls, and a cage. Also, in addition to the described parts, some bearings may have seals and washers for different purposes. High-alloy high-strength steel is the material from which the bearing races are made. Separators do not require special strength, so they are made from brass, plastic or low alloy steel.
Various loads act on the axis of the mechanism. Depending on its direction and distribution, bearings are divided into thrust, radial and radial thrust bearings.
If the axle is not loaded along its length, then radial bearings are used. These can be servos, electric motors, rear axles of a car suspension, etc.
If the load is distributed along the axis of rotation, then thrust bearings are used. In the wheel hubs of the car, bearings of the angular contact type are used. Here the efforts are directed both along the axis of rotation and across. Bearings of this kind require free play adjustment.
Bearings can have multiple rows of rollers or balls, depending on the application. They are also divided into self-aligning and non-self-aligning. In addition, a distinction is made between particularly wide, wide, normal and narrow bearings.
