In recent years, with the development of manufacturing technology, there has been an increasing demand for various types of robots with modern manufacturing technology. Such as large construction machinery, automobiles, home appliances and other automated production lines, as well as to enhance the country's high-tech strategic position of deep-sea manned submersible, humanoid bionic robot and painting, arc welding, spot welding, assembly, handling industrial robots, etc.. The key bearings for robots have an important impact on the key performance indicators such as smoothness of operation, repeatability, accuracy of movement and reliability of work.

At present, there are many types of bearings for industrial robots, such as thin-walled deep groove ball bearings, thin-walled angular contact ball bearings, thin-walled four-point contact ball bearings and thin-walled crossed roller bearings. As thin-walled four-point contact ball bearings and crossed roller bearings have the characteristics of strong ability to bear joint load, high precision, small friction torque, light weight and smooth running, they are mostly used in the waist, elbow and wrist parts of industrial robots.

A, thin-walled four-point contact ball bearing structure form

Thin-walled four-point contact ball bearings for industrial robots are usually available with and without seals. The main inner ring, outer ring, cage, steel ball or non-contact seal ring. The inner and outer rings are integral structures, the steel balls are in four-point contact with the inner and outer ring grooves, and the cage is a crowned insert structure. Suitable for installation in the wrist, elbow and other joint parts of industrial robots.

Two, thin-walled sealed four-point contact ball bearing characteristics

1、The outer diameter is smaller than the inner diameter, the rolling body diameter is smaller, the number is more, compared with the same inner diameter of the standard bearing, its weight is about 5% of the standard bearing, the cross-sectional area is about 20% of the standard bearing.

2, fixed section bearing: thin wall four point contact ball bearing series, bearing cross-sectional size is the same, not with the inner and outer diameter of the change and change.

3, can withstand radial load, two-way thrust load and overturning moment, equivalent to two sets of back-to-back installation of angular contact ball bearings, but its width is only equivalent to the width of a set of angular contact ball bearings.

Since robots entered the industrial field in the 1960s, both the number of robots and the technology of robots have developed rapidly. As the key parts of the robot special supporting bearings, some foreign bearing companies such as Japan's IKO, THK, NSK and the United States Koydon, etc. in the 1980s has been developed for the robot parts of the series of special supporting bearings, for the robot industry to provide about 80% to meet the needs of the robot basic components, for the rapid development of industrial robots has laid a solid The foundation of supporting technology has been laid for the rapid development of industrial robots.

Most of the domestic industrial robots rely on imported bearings, and a few manufacturers produce and manufacture bearings for industrial robots, but the batch size is small, the variety of specifications is small, the generalization of parts is low, the supply cycle is long, the cost is high, and the quality is unstable, these factors have seriously restricted the normal development of the domestic industrial robot industry. In order to promote the domestic industrial robots special bearing design and processing technology to improve.