Focus on the Bearing Industry for 20 Years!
Generally, when the rolling element (ball or roller) is accessed between the inner and outer rings of rolling fag bearing, a certain clearance must be left between the rolling element and the inner and outer rings.
1. When installing the bearing, if the inner ring and the shaft adopt interference fit, the inner ring will expand and the inner ring raceway will expand at the same time;
2. If the outer ring and ina bearing pedestal also adopt interference fit, the outer ring raceway will shrink.
In either case, the game will be reduced. Therefore, if the bearing before installation does not have a certain clearance, negative clearance will be generated after installation, and the rolling body (ball or roller) inside the bearing will bear an additional load, increase friction torque and temperature rise so that the bearing will bite or damage prematurely. Moreover, when the NSK bearing rotates, the rolling temperature is higher than that of other parts, and its thermal expansion will also reduce the clearance. Therefore, the bearing is also required to have a certain clearance.
But it doesn’t mean that the larger the clearance, the better. If the clearance is too large, vibration and noise will be generated during the rotation of the NTN bearing, and the load distribution inside the bearing will deteriorate, resulting in early damage. Therefore, the clearance must be appropriate and appropriate.
Advantages of internal clearance
When the bearing has internal clearance, if the inner ring is fixed, the outer ring will be in a multi-degree of freedom movable state. According to its movement direction, the clearance can be mainly divided into radial clearance, axial clearance and angular clearance. The geometric relationship of these three clearances is determined by the internal size of the bearing. In addition, the clearance also determines the contact angle of the steel ball in the bearing.