What are the parts of the general hydraulic transmission system? What is the basic principle?
Direction control loop controlling the flow direction of the hydraulic medium. With the movement direction of the direction control valve control single actuators, be positive and negative direction or stop the loop, called commutation circuit, figure a simple grinding machine hydraulic system schematic diagram of the reversing valve in the role. When the execution component stops, the circuit that prevents the leakage from the external cause, such as the payload, is called the lock loop.
The speed control loop controls the circuit of the component's movement speed by controlling the flow of the medium. It is divided into the regulation circuit and the synchronous loop. Speed control loop: (1) is used to control a single movement speed of executive element, the, can use the throttle valve or control valve to control the flow, as shown in figure a simple grinding machine hydraulic system principle diagram of the throttle valve is the role. Throttle valve control hydraulic pump into the flow of the hydraulic cylinder (excess flow through the relief valve flow back into the tank), to control the movement of the hydraulic cylinder speed, this form is called throttling speed control. It can also be used to change the output flow of the hydraulic pump to speed the speed adjustment. (2) synchronous circuit: control two or more than two components of synchronous operation circuit, for example with the method of the two components of rigid connection, to ensure synchronization; To adjust the flow of the two actuating elements by means of throttle valves or adjustable-speed valves to ensure synchronization; The line of hydraulic cylinder is connected to ensure that the flow of the two hydraulic cylinder is the same, so that the two hydraulic cylinders are synchronized.
The pressure control circuit USES the pressure control valve (see the hydraulic control valve) to control the circuit of the system or local pressure. According to the function, the pressure control circuit can be divided into four circuits: voltage, voltage, pressure and voltage. (1) the pressure circuit: this circuit USES the overflow valve to adjust the maximum constant pressure of the hydraulic source, and the overflow valve does this. When the pressure is greater than the pressure of the overflow valve, the overflow valve opens up to reduce the output pressure of the hydraulic pump, maintaining the system pressure is basically constant. (2) change pressure circuit: the pressure that is used to change the local area of the system, such as a pressure-reducing valve on the back road, can reduce the pressure of the relief valve. After a booster, the pressure of the booster is higher than the hydraulic pressure. (3) discharge circuit: when the system is not under pressure or as long as low pressure, the system pressure is reduced to zero pressure or low pressure through the discharge circuit. (4) voltage regulator circuit, in order to reduce or absorption system in the local scope of pressure fluctuation, maintain the system pressure is stable, for example, USES the accumulator in the loop.
The working principle motor drives the hydraulic pump from the oil tank, and the hydraulic pump converts the mechanical energy of the motor to the pressure of the liquid. Through pipe by the throttle valve and directional control valve for the hydraulic medium into the hydraulic cylinder the left cavity, forces the pistons to drive the workbench moves to the right, the hydraulic cylinder cavity discharge right of the directional control valve for the hydraulic medium flow back into the tank. The hydraulic medium is moved to the right cavity of the hydraulic cylinder after the reversing valve, so the piston moves to the left and pushes the table back. Changing the opening of the throttle can adjust the speed of the hydraulic cylinder. The pressure of the hydraulic system can be adjusted through the overflow valve. When drawing a hydraulic system diagram, the symbol is used as a hydraulic component for the sake of simplicity. This symbol is called a functional symbol.
Hydraulic transmission is performed by the hydraulic pump, hydraulic valve, hydraulic components (hydraulic cylinder and hydraulic motor, etc.) and auxiliary hydraulic parts (pipe and the accumulator, etc) of the hydraulic system. Hydraulic pump can convert mechanical energy to the liquid pressure, hydraulic pressure control valve and hydraulic auxiliary control hydraulic pressure, flow rate and flow direction of medium, the hydraulic pump output pressure can be passed on to perform components, components of the liquid pressure can be converted into mechanical energy, to complete the required actions.
