The rotary motor of excavator is a very important part of excavator. Once there is a problem, it is difficult to solve and will affect the use. In serious cases, there will be safety accidents such as personal injury. 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 swing motor failure from the aspects of swing overflow valve and brake valve.
Rotary relief valve or safety relief valve. Generally, there are two protruding one-way valves on the valve cover of the swing motor. When the swing motor works normally, the valve is closed. Only when the load exceeds the specified limit, that is, when the system pressure exceeds the set pressure, open the overflow and carry out overload protection, so that the slewing pressure will not increase and protect the slewing motor. In case of failure, it is fast and slow at the same time, or the speed is too slow.
Delay valve is also called brake valve or parking brake valve. Some manufacturers have rotary brake solenoid valve. It plays the role of controlling the brake in the swing motor. If the machine needs to be stopped during driving, unconscious sliding may be caused by the weight of the machine itself. Connecting the brake valve can prevent unconscious sliding of the machine. When a fault occurs, it will not rotate, or it will be very slow or slow for a while. Generally, the fault can be solved by removing the brake valve for cleaning. Dirty hydraulic oil can also cause this fault.
