Working principle of hydraulic system of tor0151e scraper
Working principle of hydraulic system of tor0151e scraper
With the downward movement of the underground stope, the underground ventilation environment is getting worse and worse. In order to reduce the exhaust pollution of diesel LHD and reduce the harm of exhaust gas to human body, a mine has begun to use tor0151e LHD instead of st2d diesel LHD. In the process of use, the main motor of tor0151e LHD has almost no failure, but the hydraulic system of the machine has failures from time to time, which directly affects the}} ore efficiency of the LHD, increases the downtime and increases the mining cost. In order to give better play to the benefits of the tot0151e LHD, technicians analyzed the working principle of the system according to the structure and composition of the hydraulic system of the machine, and diagnosed and eliminated the faults of the hydraulic system of the tot0151e LHD.
1. Steering hydraulic system
The steering hydraulic system is composed of steering pump 1, overflow valve 2, charging valve 3, steering valve 4, steering hydraulic cylinder 5 and high-pressure oil pipe, as shown in Figure 13.
The steering pump connected to the output of the torque converter transmission supplies oil to the steering valve through the relief valve and charging valve of the braking system. When the steering control lever is moved, the amount of oil proportional to the displacement of the handle passes through the steering valve. At this time, the high-pressure oil supplied by the steering pump flows to the steering hydraulic cylinder. When the control lever stops moving, the valve core automatically returns to the middle position and the car body stops at the given corner. There is also an attached pressure relief valve in the steering valve to determine the pressure of the steering system. Its set value is 15.0mpa and can be adjusted by a screw on the valve body; In order to prevent the peak load introduced by external force in the system from causing component damage, an impact overflow valve is also set up; The impact overflow valve is set to 20.0Mpa. When there is no steering action, the output of the steering pump enters the boom / bucket hydraulic system from the steering valve.
2. Boom / bucket hydraulic system
The boom / bucket hydraulic system is composed of oil suction filter element 11, hydraulic pump 8, boom / bucket control valve 9, boom hydraulic cylinder 6, double acting bucket hydraulic cylinder 7 and oil return filter 12, as shown in Figure 13.
The hydraulic pump connected to the torque converter power take-off supplies oil to the boom bucket control valve. Mechanical connection is adopted from the control handle of the cab to the control valve core. The movement of the valve core opens or closes the oil hole in the valve, so that the hydraulic oil enters the hydraulic cylinder to complete the specified action. There is also an attached hydraulic overflow valve in the boom / bucket control valve to determine the working pressure of the system, and its set value is 21.0mpa. All hydraulic cylinders are equipped with impact relief valves and anti cavitation valves to prevent damage caused by external impact. The pressure of the impact relief valve on the big head side of the piston of the bucket hydraulic cylinder is set to 6.0MPa, and the pressure of the other impact relief valves is set to 24.0mpa.
The dump valve is used to detect the load in the boom / bucket hydraulic system. When the steering system is not used, its hydraulic oil enters the boom / bucket hydraulic system through the unloading valve to speed up its action. When the pressure in the boom / bucket oil circuit is greater than 12.0mpa, the steering hydraulic oil is introduced into the hydraulic oil tank.
3. Braking system
The system is shown in Figure 14.
The tor0151e scraper is equipped with a dual oil way crane
The braking system and another parking braking system. The pressure of the reverse flow valve of the service brake system is set to 36.0mpa, and the brake oil circuit is connected with the steering oil circuit through the charging valve. The function of the charging valve is to maintain the pressure of 9.5 ~ 12.8mpa in the pressure accumulator. The two sets of oil circuits have their own pressure switches, which send a signal to the driver when the pressure is lower than 7.0Mpa. The brake pedal is used to control the pressure to the brake hydraulic cylinder, so as to control the braking force. There is a set of brake oil circuit at the front and rear axles.
Parking brake is a spring brake device that acts on the brake disc of the front axle drive shaft. The pressure of the parking brake control valve comes from the front axle brake oil circuit. When the hand brake is used, the pressure of the spring brake hydraulic cylinder is drained. When the brake is released, the spring brake hydraulic cylinder must be pressurized. At this time, the indicator light on the instrument panel goes out. There is also a solenoid valve on the car, which automatically applies the hand brake when the motor stops. The position of the parking handle has no effect on this function. When the accumulator pressure drops below 7.0Mpa, the parking / emergency braking will act automatically.
4. Cable winding hydraulic system
The hydraulic system of cable winding is shown in Figure 15.
The hydraulic oil is sent from the cable winding pump and the main cable winding pump to the cable winding control valve, flows through the hydraulic cable winding motor, and finally returns to the oil tank. The cable winding control valve adjusts the hydraulic oil pressure flowing to the hydraulic cable winding motor according to whether the cable is drawn in or drawn out. The pressure is 8.6mpa when drawn in and 6.4Mpa when drawn out. The displacement of the cable winding pump is low, and most of the hydraulic oil flow comes from the main cable winding pump installed on the gearbox, which only supplies oil when the vehicle is moving. The manual valve can eliminate the tension in the cable during maintenance. On the other hand, when there is a large section of loose cable behind the car, this valve should be opened before starting the motor. After the motor is started, slowly close the control valve and start the cable winding system, so as to avoid sudden tension on the cable.
