The cage is an important component of the bearing. Its function is to guide and separate the rolling elements, reduce bearing friction, optimize and balance the rolling element load, and improve the lubrication effect of the bearing. Observing from the appearance of the bearing, it is not necessarily guaranteed that the position of the bearing cage is consistent. The fundamental difference lies in the different guiding methods of the bearing during operation.
There are three types of guidance methods for bearing operation: rolling element guidance, inner ring guidance and outer ring guidance. The most common guidance method is rolling element guidance.
Bearings in which the bearing cage is located in the middle of the rolling elements are rolling element guides, and the cage evenly separates the rolling elements at circumferential positions. The cage does not contact or collide with the inner and outer rings of the bearing. The cage only collides with the bearing rollers to correct the rolling element motion. For bearings guided by rolling elements, first, because the cage is not in contact with the rib surfaces of the inner and outer rings, under high-speed conditions, the rotation speed of the rolling elements increases and the rotation becomes unstable; second, because this type of bearing guides The smaller the contact surface, the less impact the cage can withstand. Third, due to the large gap between the guide contact surfaces of this type of bearing, it is susceptible to impact and vibration loads. Therefore, this type of bearing is not suitable for high speed and heavy load conditions, nor is it suitable for vibration and impact load conditions.
For bearings guided by the outer ring, the cage is located on the side of the rolling elements close to the outer ring. It is an asymmetrical distribution. When the bearing is running, the cage may collide with the outer ring to correct the position of the cage. Compared with the outer ring guide bearing, the inner ring guide bearing cage 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 to correct the position of the cage. Compared with rolling element guided bearings, bearings guided by the outer ring or inner ring have higher guiding accuracy and are suitable for high speed, vibration and large acceleration operation conditions.
Due to the different bearing guide structures, the corresponding lubrication conditions are also different. For most bearings used in motors, since the motor speed is basically at a medium level, the bearing structure guided by rolling elements is more often chosen and lubricated with grease. However, for large vibration or impact load conditions, it is recommended to choose outer ring guide structure bearings and make special adjustments to the lubrication system.
Post time: Dec-11-2024