When it comes to the excavator's walking motor, I believe that many operators will have palpitations, not only because the walking motor controls the most important action of the excavator-walking, but another important reason is that the walking motor problems will cause many walking faults. Let's analyze the working process of the walking motor of Kobelco excavator.
1 Working process of walking motor at low speed
The travel speed solenoid valve is demagnetized, so the pilot pressure oil from the self-reducing valve does not flow to the oil port.
Therefore, the regulating valve (6) is completely pushed to the left by the spring (7).
Therefore, it pushes the check valve (32) so that the main pressure oil from the control valve to the end cover (5) is cut off by the regulating valve (6).
At the same time, the pressure oil in the cavity a of the regulating plunger (23) is discharged to the motor housing through the channel b of the regulating valve (6).
· As a result, the swash plate (11) is pushed toward the direction of the maximum swash plate angle by the main pressure in the cylinder chamber P, the motor capacity becomes maximum, and the system is set to low speed.
2. Working process of walking motor at high speed
When the travel speed solenoid valve is excited, the pilot pressure oil from the self-reducing valve flows to port D to push the regulating valve (6) to the right.
Therefore, the main pressure oil from the control valve passes through the channel b of the regulating valve (6), enters the bottom adjusting plunger (23), and pushes the adjusting plunger (23) to the left.
As a result, the swash plate (11) is pushed in the direction of the minimum swash plate angle, the motor capacity becomes minimum, and the system is set to high speed.
Analysis of the explosion tube of the walking motor of Kobelco excavator:
1 The oil pressure is too high, or the quality of the tubing is not good.
2 It may be caused by the instantaneous increase in pressure, you can check whether the lower oil return line is smooth, try walking in the reverse direction.
3 The quality of the changed tubing is not good.
4 Is the relief valve adjusted in a suitable position? It is recommended to exclude it from the part below the center rotary body.
5 The two-speed spool did not return in time after shifting, resulting in an instantaneous pressure that was too high, resulting in an explosion of the excavator's walking motor.
What should I do when the excavator walking motor bursts the oil pipe
1 If it is caused by the instantaneous oil pressure is too high, the elasticity of the two-speed valve spring must be increased first, then the two-speed valve must be ground to remove burrs, and finally the daily operation of the excavator must be correctly operated.
2 Adjust the relief valve on the travel motor.
3 The pressure of the safety valve of the travel pump is too high or stuck, the pump gallbladder is leaking, and the pressure of the oil return pipe is too high or blocked.
4 The oil leakage of the walking pump is too large, and the oil return pipe is the small pipe with a small finger. If there is too much oil, the small return pipe and the pump chamber will form excessive pressure.
Excavator walking motor oil leakage "general cause?
1 The oil leakage of the excavator travel motor must first observe what oil is leaking.
2 Generally speaking, the walking motor we commonly call is actually a walking motor and a reducer assembly. The motor and the reducer are two parts. The motor is hydraulic oil, and the reducer is gear oil.
3 The motor is leaking hydraulic oil, the seal is not tight, the reason is that the rubber O-ring is aging, the pipe joint is loose, and the pipe is damaged.
4 The gear oil leaks from the reducer, generally the floating oil seal is worn out, or foreign objects get stuck.
5 The reducer leaks hydraulic oil, the motor skeleton oil seal is damaged, the hydraulic oil pressure is high, and it has entered the reducer.
6 Generally, the oil distribution pan is worn and leaking oil, and then some of the skeleton oil seals are swollen.
7 The sealing ring is worn.
