Three ways to guide the cage of RDK bearing

  As an important part of bearing, cage plays the role of guiding and separating rolling element. The guiding function of cage actually refers to the correction of rolling element operation. This correction is achieved by the collision between the cage and the surrounding parts.

  There are three ways to guide the general bearing cage: rolling element guide, inner ring guide, outer ring guide.

  Roller guide:

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

  The bearing cage guided by the rolling element is located in the middle of the rolling element. The collision between cage and roller corrects the movement of roller and separates the roller at a certain equal distance.

  Outer ring guide:

  The outer ring is generally static, and the outer ring guide 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 by the rotating inner ring. The bearing cage guided by the outer ring is located on the side of the rolling element near the outer ring. When the bearing is running, the bearing cage may collide with the outer ring, so as 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, the rotation speed of each rolling element does not change much when rotating, and the rotation of cage is not unbalanced.

  Inner ring guidance:

  The inner ring is generally a rotating ring, and provides rolling element to drag torque when rotating. If the bearing load is unstable or light, it will slip.

  When the cage is guided internally, an oil film is formed on the guide surface of the cage. Due to the friction of the oil film, the drag force is exerted on the cage in the inner ring of the non load area, which increases the additional driving torque of the cage to the rolling element and prevents slipping.

  The bearing cage guided by the inner ring is located near the inner ring of the rolling element. When the bearing is running, the cage may collide with the inner ring of the bearing, so as to correct the cage position.

  Three kinds of cage guide modes may appear in different types of bearings, including performance reasons, design and manufacture of bearings. Engineers can choose according to their needs. But sometimes engineers have no choice. In any case, the different performances of different cage guiding modes should be noted.

  The differences of the three cages are mainly as follows: the performance differences of the bearings guided by the three cages are mainly as follows: the speed performance differences under different lubrication conditions.

  All three cage types of bearings can be used for oil and grease lubrication.