Typical structure of double acting vane pump
Typical structure of double acting vane pump
(2) Double acting vane pump
① YB1 series double acting fixed displacement vane pump this series of double acting vane pump is a hydraulic pump which is improved and designed on the basis of YB1 type vane pump produced by hy02 technology of the former Soviet Union. Its structure is shown in Figure s. The series pump is composed of left housing 1, right housing 4, rotor 8, blade 9, stator 7, left port plate 2, right port plate 3, pump cover 5 and transmission shaft 6. The O-ring on the right oil distribution plate can effectively prevent the leakage of the shaft end, and the seal is reliable. The left and right port plates, stator, rotor and blade of the pump can be assembled into a component (pump core for short) and installed into the shell. This assembly is initially preloaded by two fastening screws to build up pressure when the pump starts. After the pressure is established, the oil distribution plate and the stator assembly are pressed by the hydraulic pressure on the right side of the right oil distribution plate, and the pressing force increases with the increase of pressure, which automatically compensates for the axial clearance and ensures the high volumetric efficiency of the pump. YB1 series vane pump can be reversed, and any two single pumps with different displacement can form double pumps. There are 119 single and double pumps with different specifications. The maximum displacement of single pump is 100ml / R, and the rated pressure is 7MPa. Simple structure, low pressure fluctuation and noise, long life. The structure of yb-d series vane pump is basically the same as YB1 series pump, except that the stator is nitrided, the shell wall thickness is increased, and the rated pressure is increased to 1ompa.
② The vane pump is shown in Figure T. the vane pump adopts the vane structure. A vane (small vane) 5 is installed in the vane (large vane) 4, and a small cavity 2 is opened in the middle of the vane, which is always filled with high-pressure oil. The holes in rotor 6 make the pressure at the top and bottom of the blade exactly the same. In this way, in the oil absorption area, the force of the blade pressing the stator is equal to the force of the pressure oil acting on the end face area of the sub blade. Even if the pressure is high, the force will not be great. The domestic yb-e vane pump is of this kind of structure. Its rated pressure is 16MPa, the displacement is 125ml / R, and the speed range is 800-1500r / min. it has the advantages of uniform flow, small pressure pulsation, high efficiency, low noise, stable performance, long service life, etc. it only needs to turn the stator, rotor and blade 180 ° in the inner card for reverse operation.
③ Figure u shows the structure of the pin vane pump. A small pin 4 is installed at the bottom of the blade, and the pressure oil always flows through the bottom of the pin, while the oil pressure at the top and bottom of the blade 3 keeps the same at any time through the hole of the rotor 1, so that the force of the blade acting on the stator 2 is only the force of the pressure oil acting on the small pin plus the centrifugal force of the blade and pin. PFE series pin vane pump imported from ATOS company of Italy belongs to this kind of pump. Its stator, rotor, blade, pin and oil distribution plate can form a single pump core part, which can be integrated into the front and rear pump covers. The oil distribution plate adopts the axial clearance type with bilateral floating pressure compensation, so as to obtain higher volumetric efficiency. The working pressure of this series of pumps can reach 2lmpa, some as high as 32Mpa.
④ The structure of cam rotor vane pump is shown in Figure v. In order to reduce the pulsation of output flow, in addition to the special transition surface on the cam, the double acting pump is composed of two cam rotors with 90 ° phase difference installed on the common pump shaft. The two units are separated by the diaphragm 3, but connected. The working volume of the two groups of pumps compensates each other, and there is no trapped oil phenomenon, and the flow pulsation and noise are very small.
The structure of this kind of pump is quite simple, and there is no need for a special flow distribution mechanism. The front and back covers only play the role of end face seal, but the axial clearance compensation parts can also be set like the gear pump. Because of these advantages, it has developed rapidly in recent years and applied more and more. Its main disadvantage is that it can not stepless variable and the working pressure is slightly low (up to 21MPa). The cam rotor vane pump made by suer Sundstrand company in the United States is such a structure.
⑤ Double vane pump almost all forms of single vane pump can be combined into double vane pump structure, but the combination form is different. There are two common structural combination forms: through shaft type and flange type. Figure w shows the structure of through shaft double vane pump. Two rotors 2 and 3 are respectively installed at both ends of a transmission shaft L in a pump housing 4 to form pumps of different sizes with different displacement, and they share one oil suction port, but the oil pressure ports are separated [the oil suction port and the oil pressure port in Fig. w (a) are arranged above the pump housing; the oil suction port in Fig. w (b) is arranged below the pump housing, and the oil pressure port is arranged above the pump housing]. Flange type is the direct combination of two independent single pumps into a duplex pump through the connecting flange.
The double pump can be combined into three different flow rates with the help of control valve to meet the different flow requirements of the fast and slow speed of the actuator of the hydraulic system and save energy.