How to maintain the spacing between bearing moving parts in CNC machining of bearing rollers

Bearing rollers are also called rolling bearings and are similar to ball bearings because they are designed to bear the load while reducing friction. However, the bearing rollers use cylinder rolling elements instead of balls to transmit load to maintain the spacing between the moving parts of the bearing.

1. Types of bearing rollers

Types and applications of bearing rollers There are thousands of different types of roller bearings to meet specific application requirements. The five main types of bearing rollers are as follows:

Cylindrical rollers have high radial load capacity and moderate thrust load. They contain cylindrical rollers but are convex or corrugated at the ends to reduce stress concentration. The design of cylindrical bearing rollers is similar to that of needle roller bearings, but the diameter and length of the rollers are closer.

Self-aligning bearing rollers are self-aligning, double row, radial and thrust combined bearings. They use spherical or crowned rollers as rolling elements.


Tapered roller bearings consist of an inner ring (taper), an outer ring (cup), a cage and multiple rollers. The shape of these rollers allows the load to be evenly distributed throughout the bearing rollers. During operation, tapered roller bearings form line contact between raceways and rolling elements, thereby distributing the load to a larger area.

The needle bearing is a cylindrical bearing roller, in which the length of the roller is much larger than the diameter. Needle roller bearings are specifically designed for radial load applications that require a low profile.

Thrust bearings are designed for pure thrust loads and can hardly bear radial loads. Thrust roller bearings use rollers similar to other types of bearing rollers

2. Processing steps of bearing rollers

The forging is a kind of bearing steel. The steel plate is heated to 1200 degrees Celsius, fastened, worn, and polished. Usually, the smaller bearing ring is cut from the tube or rod and then precision-machined, similar to a forged part. Then, the internal and external dimensions of the blank are processed on a multi-spindle lathe. The material removed during this cutting process is called "fragment". This operation can obtain the rolling element raceways and sealing grooves required for bearing roller processing.

Quenching is a heat treatment that makes steel hard and wear-resistant. The parts are heated to 800 degrees Celsius in a quenching furnace and then "quenched", which means that they are quickly cooled by immersion in a salt or oil bath. This way the steel will harden. If this quenching operation is not carried out, the bearing ring will not be able to withstand the constant pressure of the rolling elements during operation.

The next step is grinding and honing (fine grinding). Various grinding media are used to treat rough surfaces. The finer the grinding wheel or honing stone, the smoother the surface of the raceway or rolling element. In finishing operations, the deviation must not exceed half a micron.

Deep drawing is a forming process that can economically manufacture a large number of bearing parts. First, punch out a blank from the steel bar. Then, deep-draw it into the desired shape in several steps. It can be a drawn cup-shaped needle roller bearing or a modern sheet metal ball bearing cage. Deep drawing is carried out at high pressure on a large conversion press without heating the metal plate.
Bearing roller machining

Surface coating is an important process to improve the running resistance of the bearing. The bearings are better protected from wear, high pressure and environmental influences to maintain a long service life. Various chemical and physical processes are used to apply layers on steel.

The assembly of the bearing rollers is usually carried out on the assembly line. These highly automated production lines have extensive comprehensive quality control. The use of assembly lines can achieve high-cost, high-precision mass production.