Three guiding methods of the bearing cage

During the bearing operation, the movement of the cage is the most unstable. Therefore, certain guidance must be provided to ensure the smooth operation of the cage and reduce the effect of the alternating stress of the cage and the influence of various unbalanced forces.

The rolling bearing is a kind of precision mechanical component that changes the sliding friction between the rotating shaft and the shaft seat into rolling friction, thereby reducing friction loss. It is generally composed of outer ring, inner ring, rolling element and cage.

The function of the inner ring is to cooperate with the shaft and rotate with the shaft;

The role of the outer ring is to cooperate with the bearing seat and play a supporting role;

The rolling elements are evenly distributed between the inner ring and the outer ring by means of the cage. This rotation includes both rotation and revolution. The shape and number of rolling elements directly affect the performance and life of the rolling bearing;

The bearing cage can evenly distribute the rolling elements, prevent the rolling elements from falling off, guide the rolling elements to rotate and play the role of lubrication.

The guiding effect of the bearing cage actually refers to the correction of the running of the rolling elements. This correction is achieved through the collision between the cage and surrounding parts. There are three general guidance methods for bearing cages: rolling element guidance, outer ring guidance, and inner ring guidance.

This kind of bearing cage can be used in general, but when the rolling element speed increases at high speed, the rotation is unstable, so the rolling element guide is suitable for medium speed and medium load, such as gear box bearings.

 02  Outer ring guide            

The bearing cage guided by the outer ring is located on the side of the rolling element close to the outer ring. When the bearing is running, the bearing cage may collide with the outer ring of the bearing to correct the position of the cage. The outer ring is generally stationary, and the outer ring guide facilitates the lubricating oil to enter the guide surface and raceway. If the high-speed gearbox is lubricated by oil mist, the rotating inner ring guide will squeeze out the oil.

The outer ring guide cage is generally used for high-speed and stable load conditions, such as the intermediate bearing auxiliary row, which bears a fixed value of axial load. The speed of each ball does not change much during rotation, and the rotation of the cage will not be unbalanced.

03  Inner ring guide            

The bearing cage guided by the inner ring is located where the rolling elements are close to the inner ring. When the bearing is running, the cage may collide with the inner ring of the bearing to correct the position of the cage.

The inner ring is generally a rotating ferrule, and provides rolling elements to drag torque when rotating. If the bearing load is unstable or the load is light, slippage will occur. While the cage adopts internal guidance, an oil film is formed on the guide surface of the cage. Due to the friction of the oil film, the drag force is applied to the cage in the non-load zone, thereby increasing the additional driving torque of the cage to the rolling elements and preventing slippage.

The bearing cage guided by the inner or outer ring can provide more precise guidance, and is usually used when the bearing configuration must withstand high speeds, frequent and rapid accelerations, or high vibration levels. When the bearing is running, appropriate measures must be taken to provide sufficient lubricant for the guide surface of the cage.