It also depends on the volume change to end the oil suction and pressure. However, in order to ensure that the oil suction and pressure ports are separated, a crescent diaphragm should be added to the base of the involute gear pump. Since the two gears in the cycloid gear pump are only one tooth apart, the oil suction and pressure can always be guaranteed when meshing No communication, no crescent partition is needed.
2. Plunger pump
According to whether the plunger and the drive shaft are vertical or parallel, hydraulic pumps are divided into radial plunger pumps and axial plunger pumps. It uses the reciprocating movement of the plunger in the plunger hole to change the volume and end oil suction and pressure. of.
(1) Radial plunger pump is composed of stator, rotor, shaft sleeve, oil distribution shaft and plunger. There is an offset distance e between the rotor and the stator base. The oil distribution shaft is fixed, and an oil distribution window is opened along the circumferential direction. The upper half of the oil distribution window corresponds to the oil suction port, and the lower half of the oil distribution window corresponds to the oil pressure port. When the rotor rotates clockwise, due to the existence of e. The plunger in the upper half is thrown out along the plunger hole under the action of centrifugal force. The volume at the bottom of the plunger continues to increase. A vacuum is formed, and the oil is sucked into the oil cavity through the oil suction port on the oil distribution shaft. When the plunger continues to rotate to the second half of the circle. The volume at the bottom of the plunger continues to decrease, at this moment the oil is compressed and the pressure begins to rise. Feed into the system through the oil pressure port. Every time the rotor rotates for one week, the process of sucking and pressing oil is finished. The displacement or flow of the pump can be changed by adjusting the e value, so it is also called a variable pump.
(2) The characteristic of the axial hydraulic pump is that the plunger hole is parallel to the axis. It is composed of swash plate, plunger, cylinder, oil distribution plate, transmission shaft, return plate, return spring and other elements. The axis of the swash plate has an included angle with the drive shaft, and the plunger is tightly attached to the oil distribution plate under the action of the return plate, the return spring and the oil pressure.
3. Vane pump
Hydraulic pumps are classified into single-acting vane pumps and double-acting vane pumps according to the number of suction and pressure oil per revolution. Single-acting vane pumps are also called variable vane pumps or unbalanced vane pumps. The pump shaft sucks and presses oil once a week. The double vane pump is called a quantitative vane pump or a balanced vane pump. The pump shaft sucks and presses oil twice a week.