After a hydraulic motor has been in use for a period of time, its rotational speed may likely decrease. What factors could cause the decrease in the rotational speed of a hydraulic motor?
Causes:
Pump damage: The pump casing overheats and produces noise.
Pressure regulating valve is stuck closed, or the oil supply and return system is blocked, leading to local overheating.
Relief valve is open: The valve produces a humming or hissing sound, and the hydraulic drive motor overheats locally.
Excessive leakage in the oil distribution rotary valve: The valve chamber overheats and feels very hot when touched by hand.
Excessive leakage in the hydraulic motor crankcase: The leakage from the single drain pipe is excessive, and the oil level is relatively high.
Solutions:
Check the condition of the spherical hinge.
Check the sealing condition of the cylinder block piston.
Check the oil viscosity and operating temperature.
Check the surface between the oil passage disc and the housing.
Check the condition between the crankshaft hydraulic transmission motor and the rack surface, as well as the sealing condition of the oil distribution rotary valve.
Check the wear condition of the oil passage disc, and verify whether the channels of the two oil chambers at the oil inlet and outlet holes of the casting are connected (i.e., whether internal communication occurs).
