The working principle of stage lift mainly includes three methods: hydraulic drive, screw drive and scissor-type structure.
Hydraulic drive principle
The hydraulically driven stage lift is mainly composed of hydraulic pump station, hydraulic cylinder, hydraulic pipeline and control valve. The hydraulic pump station provides power to convert mechanical energy into hydraulic energy, usually composed of motor and oil pump. The hydraulic cylinder is an actuator that converts hydraulic energy into mechanical energy to push the stage up or down. When the motor starts, it drives the oil pump to work, and the oil pump sucks oil from the oil tank and delivers the pressure oil to the hydraulic cylinder through the hydraulic pipeline. If the stage is to be raised, the control valve guides the pressure oil to the lower part of the piston of the hydraulic cylinder (for single-acting hydraulic cylinder) or both sides of the piston (for double-acting hydraulic cylinder), pushing the piston upward, so that the stage rises. When the stage needs to be lowered, the valve of the return oil pipeline can be opened to allow the oil in the hydraulic cylinder to flow back to the oil tank under the action of the stage's own gravity and load, or the control valve can be used to change the flow direction of the oil so that the upper chamber of the piston enters the oil and the lower chamber returns the oil, thereby achieving the descent of the stage.
Screw drive principle
The screw-driven stage lift consists of a screw, a nut, a motor and a transmission device. The motor drives the screw to rotate through a transmission device (such as a belt, gear, etc.). When the motor drives the screw to rotate, if the nut is restricted from rotating (usually through a guide rail or other device), the nut will move along the axis of the screw. For example, the nut is connected to the stage surface, and the screw is fixed to the support structure. When the screw rotates clockwise, the nut drives the stage to rise; when the screw rotates counterclockwise, the nut drives the stage to fall.
Scissor-type structure principle
The scissor-type lifting stage consists of multiple sets of intersecting scissor arms, which are connected by pins, and rollers or sliders are installed at the bottom to smoothly extend and retract. Taking the hydraulic scissor-type lifting stage as an example, one end of the hydraulic cylinder is connected to the bottom or a node in the middle of the scissor arm. When the hydraulic cylinder is extended and retracted, it will push the angle of the scissor arm to change. When the oil cylinder extends, the scissor arms gradually open and the stage rises; when the oil cylinder contracts, the scissor arms close and the stage descends. Its principle is based on the stability of triangles and the proportional relationship between the side lengths of similar triangles, and the vertical lifting of the stage is achieved through the linkage of various components.