2022 November the Four Week KYOCM Technical Knowledge: Three Guiding Modes of Bearing Cage

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

Rolling bearing is a kind of precise mechanical element that changes the sliding friction between the running shaft and the shaft seat into rolling friction, so as to reduce the friction loss. It is generally composed of outer ring, inner ring, rolling element and cage.

The role of the inner ring is to match the shaft and rotate with the shaft;

The outer ring plays a supporting role by matching with the bearing seat;

The rolling element is evenly distributed between the inner ring and the outer ring by means of the cage. This rotation includes both rotation and revolution. The shape, size and quantity of the rolling element directly affect the service performance and life of the rolling bearing;

The cage can make the rolling bodies evenly distributed, prevent the rolling bodies from falling off, guide the rolling bodies to rotate for lubrication, and guide and separate the rolling bodies.

The guiding function of cage actually refers to the correction of rolling element operation. This correction is achieved by collision between cage and surrounding parts. Generally, there are three ways to guide the bearing cage: rolling element guide, inner ring guide and outer ring guide.

1 Rolling element guidance:

The standard structure of general design is the roller guide, such as short cylindrical roller bearing, which uses the roller guide. The cage does not contact the rib surface of the inner and outer rings. The cage can be used universally. However, when the speed of the roller increases at high speed, the rotation is unstable. Therefore, the roller guide is suitable for medium speed and medium load, such as gearbox bearings.

The bearing cage guided by the rolling element is located in the middle of the rolling element. The cage and the inner and outer rings of the bearing are free from contact and collision. The collision between the cage and the roller corrects the roller movement and separates the rollers at a certain equidistant position.

2 Outer ring guide:

The outer ring is generally static, and the guide of the outer ring is convenient for lubricating oil to enter the guide surface and raceway. The high-speed gearbox is lubricated by oil mist, and the oil will be squeezed out if it is guided by the rotating inner ring. The bearing cage guided by the outer ring is located at 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 cage position.

The outer ring guide is generally used in the case of high speed and stable load. Take the cylindrical roller bearing as an example. It only bears a fixed value of axial load. When rotating, the rotational speed of each rolling element changes little, and the rotation of the cage does not cause imbalance.

3 Inner ring guide:

The inner ring is generally a rotating ring and provides a rolling element to drag torque when rotating. If the bearing load is unstable or light, it will slip. While the cage adopts internal guidance, an oil film is formed on the guide surface of the cage. As the friction of the oil film drives the cage in the inner ring of the non load area, the additional driving torque of the cage to the rolling element is increased, which can prevent slipping.

The bearing cage guided by the inner race is located near the inner race of the rolling element. When the bearing is running, the cage may collide with the inner race of the bearing, thus correcting the cage position.

Cages guided by inner or outer rings can provide more accurate guidance, and are usually used when bearing configurations must withstand high rotational speeds, frequent and rapid accelerations, or high vibration levels. When the bearing is running, proper measures must be taken to provide sufficient lubricant for the guide surface of the cage.

More about KYOCM Cylindrical Roller Bearing：

The bearings can meet the challenges of applications faced with heavy radial loads and high speeds. Accommodating axial displacement (except for bearings with flanges on both the inner and outer rings), they offer high stiffness, low friction and long service life.

Cylindrical roller bearings are also available in sealed or split designs. In sealed bearings, the rollers are protected from contaminants, water and dust, while providing lubricant retention and contaminant exclusion. This provides lower friction and longer service life. Split bearings are intended primarily for bearing arrangements which are difficult to access, such as crank shafts, where they simplify maintenance and replacements.

We’re professional cylindrical roller bearing suppliers in China, specialized in providing high quality products and service. We warmly welcome you to buy high-grade cylindrical roller bearing at competitive price from our factory. For more information, contact us now.