Generally, it is caused by the difference in the pressure of the oil entering the oil motor on both sides. The side with the higher oil pressure will naturally go faster. During the inspection, two oil pressure gauges can be installed on the pressure measuring ports of the walking oil motors on both sides. If the pressure difference is large, the side of the safety valve can be adjusted a little higher. If the pressure is the same on both sides, it is that the oil flow rate sent by the two plunger pumps is different (how to adjust the pump flow rate, specifically introduced in Part 2). If the model 3 and model 5 cannot go straight, check the straight control valve.
Why can't the excavator stop on the slope?
Generally, the excavator can be stopped on the slope, because the excavator walking pump itself has a braking device, as long as no liquid is supplied
Press the motor to supply oil, the braking device acts as a brake, and there are a pair of shuttle valves installed in the two motor circuits in the system. Before the hydraulic oil P enters the travel motor, there is a way of oil to enter the A end of the reciprocating valve, so that the reciprocating valve is displaced to B; the pressure oil P has a way of oil through the reciprocating valve to the brake spool, the brake spool to the spring The direction is shifted, so that the hydraulic oil reaches the motor braking device, and the motor starts to rotate. The brakes are also released and almost synchronized. When the oil supply to the motor stops, the shuttle valve and brake valve are automatically reset. The motor brakes at the same time, and the shuttle valve interrupts the flow of oil in the pipeline. Since the oil cannot flow, the shuttle valve also acts as a brake. If the excavator can't stop on the slope, you must check the leakage of the shuttle valve.
Why does the PCA00-3 excavator not have a quick stop?
The control oil of the variable speed spool valve comes from the control pump. There is an electromagnetic switch to control the speed in the cab. The control oil needs to pass through the solenoid valve controlled by this switch to reach the variable speed spool valve. If the solenoid valve is broken, the speed cannot be changed. When the fast gear is opened, the 2-position 4-way solenoid valve moves to the right, the control oil reaches the lower end of the spool valve through the solenoid valve, the spool valve moves up, and the high-pressure oil that enters the upper cavity of the servo valve is cut off. Also enter the lower cavity of the servo valve, push the servo valve piston up to make the motor variable.
What is the reason why the rotary motor of the turntable cannot turn?
From Komatsu type 3 to type 6 excavators, the turntable is equipped with a parking brake device. If the brake solenoid valve is faulty or the control circuit is faulty, it will cause the motor brake device to not open.
If the rotary speed change brake solenoid valve is broken. Are there any emergency measures?
The function of the solenoid valve is mainly to move the 2 / 3-way valve to the left and right, so as to cut off or connect the control oil circuit. We can connect hose A directly to the connector of hose B. The motor can be rotated without passing through the solenoid valve temporarily.
Why is it difficult to stop at the position where the turntable is rotating?
This is because the locking function of the swing motor has deteriorated.
Is the structure and working principle of rotary motor and walking motor the same?
Is basically the same, except that the walking motor has an automatic braking device and the rotary motor does not.
Why does the turntable stop?
When the oil supply to the motor is stopped, the inlet and outlet oil paths of the motor are blocked by the distribution valve. At this time, the motor cannot rotate regardless of the direction. Only when the two overload valves are faulty or the pressure is adjusted too low, the hydraulic oil will overflow when the overload valve overflows, and the motor will fail to stop.
