Bearing Cage Types, Functions And Damage Causes

Bearing cage (also known as bearing retainer) refers to a bearing part that partially wraps all or part of the rolling elements and moves with them, isolating the rolling elements, and usually guiding the rolling elements and keeping them in the bearing.

There are three main types of bearing cages: nylon cages, window-type stamped steel cages and window-type brass cages. The following are the advantages and disadvantages of different types of bearing retainers introduced by China Bearing Network.

Nylon cage: The advantages are light weight, strong elasticity, good sliding performance, good marginal lubrication performance, and the disadvantage is that the operating temperature must be used below 120 degrees Celsius.

Window-type stamped steel cage: The advantages are light weight, high strength, no operating temperature limit, high-end shock resistance and acceleration resistance, and the disadvantage is sensitivity to poor lubrication.

Window-type brass cage: The advantages are extremely high strength, extremely high shock resistance and acceleration resistance, suitable for ultra-high-speed operation related to circulating oil lubrication. Disadvantages: relatively (very) expensive.

The main functions of the bearing cage are:

1. The cage separates the rolling elements at equal distances and distributes them evenly on the circumference of the raceway to prevent the rolling elements from colliding and rubbing against each other during operation;
2. Guide and drive the rolling elements to roll on the correct raceway;
3. In the split bearing, the rolling element and a ring are combined to prevent the rolling element from falling off;

The reasons for the damage of the bearing cage are:

1. Insufficient bearing lubrication. The lubricating oil or grease dries up, is not added in time (maintenance), and the lubricating oil or grease is not used with the right grade.
2. Impact load of the bearing. The violent vibration in the impact load causes the rolling element to hit the cage.
3. Cleanliness of the bearing. The bearing is not well sealed in the bearing box, and dust enters, which increases the friction between the rolling element and the cage, thereby damaging the cage.
4. Wrong material selection of the bearing cage. Various cage materials have certain requirements for temperature resistance and speed. If the material selection is wrong, it is also the cause of cage damage.
5. Installation problem. If the bearing is not installed correctly, the cage will be damaged during installation.
6. Other reasons. For example, the misalignment of the coupling will cause the bearing to be skewed and uneven force; the belt is installed too tightly; environmental problems, etc. may damage the bearing or cage.