Mine explosion-proof hydraulic hoist working principle
Mine explosion-proof hydraulic hoist consists of mechanical, hydraulic transmission, electrical parts and other components. The squirrel-cage type explosion-proof main motor drives the bidirectional variable main oil pump; the main oil pump and two curves low-speed high-torque hydraulic motors constitute a closed-loop, balanced-torque hydraulic speed control system; two hydraulic motors are arranged on both sides of the main group device and the main Connect the groups and drag the hoist to run.
The hoist has two auxiliary oil pumps, one working and one spare. In the auxiliary oil pump, the big pump is used as the charge pump, and the main hydraulic transmission is used to make up the oil; the small pump is used for control, and the braking system, the operating system, and the regulating rope system are supplied with oil.
The lifter uses long-range hydraulic control. The driver inputs the low-to-high pressure oil from the proportional cylinder piloted by the hydraulic proportional pilot to the main pump, so that the stroke regulator of the main oil pump acts, changes the inclination of the cylinder of the main oil pump to change the flow of the main oil pump to change The speed of the hydraulic motor makes the hoist start and speed up.
The driver can pull the handle of the hydraulic proportional pilot to pull at different angles, so that the main oil pump can output different flow, so that the hoist can get different lifting speeds. When the hydraulic proportional pilot is pulled to the maximum position, the lifting speed is maximum. When the hydraulic proportional pilot cut handle is pulled to the neutral position, the hoist stops. When the handle is pulled in the opposite direction, the hoist runs in the opposite direction.
The hoist uses disc brakes to achieve normal and emergency braking of the hoist. The brake force of normal braking is generated by the hydraulic transmission itself. The load becomes the braking force when lifting. When the weight is lowered, the hydraulic motor becomes a pump. The hydraulic pump becomes a hydraulic motor. Make the motor generate power feedback brake. Disc brakes do not participate in working brakes. It is used as a safety device only after the hoist drum stops operating. When the hoist fails during operation, the safety device automatically works, and the driver can also use the foot switch to stop the brake.
When there is pressure oil in the lifting brake system, the disc brake is opened and there is no pressure oil disc brake. There are 4 pressure reducing valves in the hydraulic proportional pilot operated by the driver. Two of the pressure reducing valves operate the forward and reverse oil supply of the main oil pump, and the other two pressure reducing valves control the opening of the disc brakes. When the driver operates the hydraulic pressure ratio During the pilot cutting, two valves are pressed at the same time, and the pressure oil output from one valve is fed into the proportional cylinder of the main pump, so that the main pump supplies oil to the hydraulic motor and makes it run. The pressure oil output from the other valve is supplied to the hydraulically controlled reversing valve of the brake system, so that the brake system supplies oil to the disc brake, and the disc brake is opened to operate the hoist. When the driver pulls back the hydraulic proportional pilot, the handle is pulled to the neutral position. (The proportional cylinder returns to the neutral position) The main pump flow gradually decreases to zero and the hydraulic motor stops running. At the same time, the hydraulic control reversing valve is reset due to no pressure oil and the hoist brakes. In this way, when the lifting operation is started, the disc brakes are opened at the same time, and when the hoist stops, the disc brakes are braked at the same time and the safe operation of the hoisting machine is guaranteed.
The safety protection function of the hoist is complete, with overload, over-wound, over-speed, no deceleration point deceleration, brake shoe wear, high-pressure oil over-pressure, oil shortage, short circuit, open circuit, zero and other faults. At the same time with oil temperature oil level signal. The hoist has a microcomputer-controlled explosion-proof intrinsically safe integrated backup protection device. It has the functions of lifting depth, speed display, overspeed, deceleration, deceleration, overwinding, and depth indicator failure protection, and improves the backup display function such as signal display, memory, and lifting hook count calculation.
