What role does the clearance of needle roller bearings play in work?

The clearance of a needle roller bearing is simply the gap between the needle rollers and the raceway.

The presence of clearance can compensate for thermal expansion effects. During the operation of mechanical equipment, friction and temperature changes in the external environment can cause the bearing and surrounding components to expand thermally. If there is not enough clearance to accommodate this expansion, the bearing will become too tight, leading to increased internal stress and eventually overheating and damage. With a reasonable clearance design, needle roller bearings can maintain an appropriate tightness under different temperature conditions, thus avoiding excessive wear and tear and failure.

When needle rollers roll freely in the raceway, a certain amount of clearance is required to reduce friction between the contact surfaces. If the clearance is too small, the friction force between the needle rollers and the raceway will increase, which will not only cause the bearing to overheat but also aggravate wear and tear, and even lead to bearing seizure. Conversely, proper clearance can ensure that the needle rollers run smoothly, reduce friction losses, and extend the bearing service life.

In the operation of machinery, external vibrations and shocks are inevitable. Reasonable clearance can also play a buffering role, reducing the direct impact of these vibrations and shocks on the bearing, thereby protecting the stability and integrity of the bearing.