The rotary motor of excavator is a very important part of excavator. Once there is a problem, it is difficult to deal with. It will not only affect the use, but also cause personal injury and other safety accidents in serious cases. The rotary motor is an axial plunger hydraulic motor, which generates torque through the reaction generated by applying high-pressure hydraulic oil to the reciprocating plunger. The torque is applied to the drive shaft. After decelerating through the rotary reducer, the power is output and acts on the rotary support to make the upper part of the excavator rotate left and right. This article will describe the causes of rotary motor failure from the aspects of oil makeup valve, plunger, valve plate and brake pad, which is for reference only.
The makeup valve, or makeup valve, protects the swing motor by providing return oil to the swing motor to prevent cavitation in the swing motor. The fault phenomenon of swing motor is slow acceleration and slow speed.
Plunger, valve plate and brake pad are the main components inside the rotary motor and the main power source of the rotary motor. The fault phenomena are as follows:
1. The clearance between the plunger and the cylinder block column plug hole is worn and increased, resulting in serious clearance leakage. The plunger needs to be replaced.
2. The return spring is tired and the elasticity decreases, resulting in collusion between high and low pressure oil circuits of the cylinder block. The spring needs to be replaced.
3. The wear of sliding shoe and plunger accelerates the sliding dry friction between sliding shoe and pressure plate, resulting in the increase of rotation resistance. It needs to be repaired or replaced.
4. The bearing of the swing motor is damaged and the bearing cannot be positioned. The bearing of the specified model needs to be replaced.
5. 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.
6. The aging failure of the parking brake pad causes the brake to not be released completely and the turning resistance increases. The sealing element must be replaced.
