The advantages of vane pump are: smooth operation, small pressure pulsation, low noise, compact structure, small size, large flow. Its disadvantages are: high requirements for oil, such as impurities in the oil, the blade is easy to jam; Compared with gear pump structure is more complex. It is widely used in special machine tools in mechanical manufacturing, automatic lines and other medium and low pressure hydraulic systems.
1. Main characteristics of single acting vane pump
(1) The single-acting vane pump can adjust the displacement and flow rate of the pump by changing the stator eccentricity E.
(2) The groove root of the blade is oiled, and the blade thickness has no effect on the displacement.
(3) Because the axial diameter of the blade is a function of the rotation Angle, the instantaneous theoretical flow is pulsating. The number of blades is odd to reduce the pulsation of flow.
2. Main characteristics of double-acting vane pump
(1) Radial force balance of double-acting vane pump
(2) In order to ensure that the blade is free to slide and always close to the inner surface of the stator, the blade groove root is all through pressure oil.
(3) Reasonable design of transition curve shape and blade number (z≥8) can make the theoretical flow uniform and low noise.
(4) the central Angle of the circular arc section of the stator curve β≥ the spacing Angle of the flow distribution window γ≥ the included Angle between the blades α (= 2π/ z).
In order to reduce the pressure shock caused by the sudden change of pressure when the closed volume between the two blades is converted into the suction oil chamber, a damping groove is provided at the front of the distribution window of the valve plate.
Double-acting vane pump pressure oil to the bottom of the blade, blade balance at the top of the liquid pressure, to ensure good contact with the inner surface of the stator blade, but at the bottom of the blade after oil absorption, leaves no hydraulic pressure, additional blade at the bottom of the liquid pressure will aggravate blade wear, but in order to reduce the hydraulic shock and noise, avoiding the phenomenon of trapped oil, can be solved by unloading trough.
