A bearing cage refers to a bearing part that partially covers all or part of a rolling element and moves with it to isolate the rolling element, usually guiding the rolling element and keeping it in the bearing.

1) the main role of bearing cage

1. Keep a proper distance between the rolling bodies to prevent the rolling bodies from contacting each other to reduce friction;

2. Make the rolling body evenly distributed, so as to make the load evenly distributed;

3. Guide the rolling body in the no-load area to improve the rolling conditions in the bearing and prevent damaging sliding.

The cages are subjected to stresses caused by friction, strain and inertia forces, as well as to chemical corrosion of lubricants, additives in lubricants or substances produced by their aging, organic solvents or coolants. Therefore, the design and material of the cage are very important for its performance and the reliability of the bearing.

2) Type of bearing cage

Bearing cages are divided into stamping cages (figure 1), solid cages (figure 2) and prop cages

1. The advantages of the stamping cage are light weight, large space inside, which is convenient for lubricant to enter;

2. The solid cage can usually allow a higher speed. When the bearing has other forms of motion other than rotation, especially at high speed, the machine cutting metal cage should also be used;

3. The pillar cage is threaded through the perforated roller with pins, and both ends of the pins are fixed on the washer. This cage is light in weight and can accommodate more rollers. It is only used for extra-large roller bearings.

3）Material of bearing cage

The cage materials mainly include stamping steel, machine cut steel, stamping brass, machine cut brass, polymer materials, etc.

Stamped steel cage has high strength and can reduce friction and wear through surface treatment. Machined steel cages are generally used for extra-large bearings or brass cages are not suitable for use; Stamped brass cage for some small and medium-sized bearings; Machined brass cage is generally not affected by the lubricant of the bearing, and can be cleaned with ordinary lubricant. The brass cage is not applied to the working temperature above 250℃. Polymeric material (nylon 66, nylon 46, etc.) cage compared with metal cage, has good toughness, friction and wear resistance, impact resistance, acid resistance, corrosion resistance and many other advantages.