Fitco Engineers Pvt. Ltd. Mumbai, Maharashtra

Thrust bearings are a particular type of rotary bearing that allow rotation between parts used but they are designed to support axial loads like vertical shafts for which spherical, conical or cylindrical rollers are used. They are used in gear sets like in car transmissions betweengearsand between the housing and the rotating shafts.

Thrust bearings are of different varieties. Ball thrust bearings are composed of ball bearings supported in a ring. They are used in low thrust applications where the radial load is very small. Thrust roller bearings are made of small tapered rollers arranged so that their axes converge at a point on the axis of the bearing.

The deep groove ball bearing is the most widely used roller bearing. Its structure is simple and is easy of use. It is mainly used to bear the radial load. By means of increasing the rib height coefficient, the radial play, etc., the deep-groove ball bearing may have a certain performance of the angular contact ball bearing, i.e. bearing a certain radial load. Compared with other kinds of bearings of the same size, the deep groove ball bearing features lower friction coefficient and high speed limit, but it has low impact resistance and is not applicable to bearing heavy load.

The cylindrical roller bearing belongs to the separable bearing, which is easy to assemble and disassemble. According to the row number of rollers, the cylindrical roller bearings can be classified into single-row, double-row, four-row, and full-complement cylindrical roller bearings. The cylindrical roller bearings can bear high radial loads and are applicable for high-acceleration and high-speed rotation cases.

Tapered roller bearings use conical rollers that run on conical races. Both the inner and outer raceways are segments of cones and the rollers are also made with a taper. Unlike other roller bearings, they support both radial and axial loads, and are able to carry higher loads. The conical geometry of tapered roller bearings provide a larger contact patch, which allows greater loads to be carried as compared to spherical (ball) bearings. The geometry ensures that the tangential speeds of the surfaces of each of the rollers are same as their raceways along the whole length of the contact patch and no differential scrubbing occurs. This greatly reduces rolling friction and avoids rapid wear. Taper roller bearings are used in the wheel bearings of most trucks, buses, cars, and so on. Due to manufacturing complexities, tapered roller bearings are generally more expensive than ball bearings.