Plunger, valve plate and brake pad are the main internal components of rotary motor, and also the main power source of rotary motor. The fault phenomenon is that the clearance between plunger and cylinder plug hole is increased, resulting in serious clearance leakage. The plunger needs to be replaced. The return spring is fatigued and the elastic force decreases, which leads to the collusion of the high and low pressure oil circuits of the cylinder block. The spring needs to be replaced. The wear of slipper and plunger accelerates the dry sliding friction between slipper and bearing plate, resulting in the increase of rotary resistance. It needs to be repaired or replaced. The slewing motor bearing is damaged, and the bearing cannot be positioned. It is necessary to replace the bearing of specified model. The oil distribution surface of valve plate and cylinder block is worn, resulting in internal leakage and weak rotation. It needs to be repaired or replaced. The aging failure of parking brake pad leads to the brake can not be completely released and the turning resistance increases. The sealing element must be replaced.
