ome of the premature failures experienced by slewing ring bearings can be prevented through careful monitoring of symptoms. One of the most basic indicators of slewing ring bearing problems is the condition of the lubricant. If metal particles or flakes are apparent, some form of wear is taking place.

Grinding, popping, or clicking noises from the bearing typically mean there is inadequate lubrication and/or excessive wear in the raceway.

Excessive play or movement Excavator Slewing Ring signifies that the raceways are worn. As clearance increases, wear is usually accelerated, making close monitoring critical. The play, or clearance, in a slewing ring bearing is another important indicator of a problem. A new bearing is assembled with a specific amount of clearance to compensate for slight out-of-flatness encountered in a mounting structure. This clearance can increase dramatically due to wear.

An increase in torque or binding can mean that there is uneven wear in the raceway. If the turning torque of the bearing increases substantially or if the bearing has tight spots, this usually indicates an uneven load distribution. With excavators, for example, the operator may NSK 35bd5020 Bearing notice a wobbling or rocking motion in the upper structure, especially when the digging arm is extended with a load. The operator may also sense a resistance to swing and find that the upper swings an inch or two past the point where it should have come to a stop. In advanced stages of wear, the bearing will pop and crack as the machine digs and wings.