What are bearing retainers?　　

Bearing retainer, also known as bearing cage, is one of the main parts of the bearing. Its role is to wrap and isolate the rolling body and move with it, and usually also has the role of guiding the rolling body. The cage is subjected to stresses caused by friction, strain and inertia forces, and also to the chemically corrosive effects of lubricants, additives in lubricants or substances due to their aging, organic solvents or coolants. Therefore, the design and material of the cage are extremely important for its performance and the reliability of the bearing.

　　The bearing retainer plays a role in keeping the proper distance between the rolling bodies to prevent the rolling bodies from contacting each other to reduce friction; to make the rolling bodies evenly distributed so that the load is evenly distributed; to guide the rolling bodies in the no-load area to improve the rolling conditions in the bearing and prevent damaging sliding.

　　What are the materials of bearing retainers?

Commonly used cages are mainly metal cages and non-metal cages by material type. There are also composite cages. The types of cage material are: mild steel stainless steel cage, rubber/plastic (nylon) cage, brass/bronze/aluminum alloy cage, etc.

　　Special purpose bearing cage should also meet the requirements of special working conditions. Such as high temperature resistance, corrosion resistance, self-lubricating (used in vacuum) or non-magnetic, etc. .

　　1、Steel cage material

　　Due to high strength, good toughness, easy processing and other characteristics, steel cage material is commonly used in rolling bearings. Often used 08 and 10 carbon steel thin plate cold stamping. In addition, can also be used according to the need for other mechanical processing methods to obtain. Commonly used steel cage materials are also 20, 30, 45, 0Cr18Ni9, 1Cr18Ni9Ti, 40CrNiMo, ML15, ML20, etc. Steel cages are generally heat treated to eliminate stress and restore plasticity. Including high temperature tempering, recrystallization annealing, etc. In order to reduce the friction coefficient of steel cage, if necessary, the finished cage must be surface treated.

　　2、Brass cage

　　There are two kinds of stamping and solid, stamping is only suitable for small and medium-sized. Brass plate, brass castings or brass forgings brass has high tensile strength, mechanical strength and steel plate stamping cage equivalent, but the density is relatively small, high limit speed. Not affected by lubricants, including synthetic oil and grease; brass cage can not be used above 300 ° C, not suitable for use in ammonia (such as cooling), because ammonia will cause brass seasonal broken, working temperature below 300 ° C.

　　3、Nonferrous metal cage material

　　Different from steel, non-ferrous metals have their special properties, for example, aluminum alloy has the characteristics of low density, good thermal conductivity and good corrosion resistance; copper alloy has the characteristics of good thermal conductivity, small friction coefficient, good formability and high use temperature; zinc-aluminum alloy has the advantages of low cost, small density and excellent performance.

　　4、Non-metallic cage materials

　　Non-metallic cage materials are mainly polymers and their composite materials, including nylon, phenolic tape, polytetrafluoroethylene, etc.. Polymer materials have good strength and elasticity matching. The good sliding performance makes the polymer cage in the relative motion with the lubricated rolling element surface only a small friction, which can make the bearing heat and wear down to a low. In the absence of lubricant, the polymer cage still has good motion characteristics. This ensures that the bearing will continue to run for a period of time without damage. Because of the low density of the polymer, the cage made from it has less inertia.

　　In addition to the pure material, the cage is also made of modified polymer material. Other materials are used for filling or reinforcement.

　　Different materials of bearing cage have their own special properties and advantages and disadvantages, you should consider the economic factors in addition to the choice, but also according to the actual needs to choose.