JPS6237985Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a vane type pump device.

[Prior art]

Generally, in a vane type pump device, a rotor holding a plurality of vanes radially is housed inside a cam ring, and a plurality of pumps are partitioned by each vane by a pair of side plates that are tightly attached to both end surfaces of the cam ring. A chamber is formed, and working fluid is sucked into the pump chamber and pressurized fluid is discharged from the pump chamber as the volume of the pump chamber changes as the rotor rotates. In a vane type pump device having such a configuration, for example,
As shown in Publication No. 54-5201, in order to balance the fluid pressure acting on the rotor, the cam surfaces of the cam ring are formed symmetrically with a 180° phase, and the two discharge ports are also formed symmetrically with a 180° phase. and are arranged symmetrically.

[Problem that the invention attempts to solve]

Therefore, in a vane type pump device having such a configuration, pulsations occur simultaneously in the pressure fluids discharged from the two discharge ports, and when these pressure fluids merge in the same pressure chamber, the pulsations resonate, causing vibrations and It was making a lot of noise. In addition, as a means for suppressing such pulsation resonance, a method has been proposed in which an accumulator or a damping plate for absorbing pulsation is incorporated into the inside of the pump device, but this method has the drawback that the structure is complicated and large.

In view of this situation, the present invention attempts to actively prevent the resonance of the pulsation of the pressure fluid with a simple structure by effectively utilizing an end cover fixed to one end of the pump housing.

[Means for solving problems]

In order to solve this problem, the present invention provides a cam ring that accommodates a rotor that holds a plurality of vanes radially, and has cam surfaces on which the vanes slide in sliding contact with the inner peripheral surface of the cam ring, which are formed symmetrically with a 180° phase. A pair of side plates that are in close contact with both end surfaces of the cam ring to form a pump chamber partitioned by the respective bases are assembled into the hollow chamber of the pump housing, and these parts are fixed to the outer opening end of the hollow chamber. The pump housing is held in a predetermined position by an end cover constituting the outer side of one end of the pump housing, and the side plate has a pair of suction ports communicating with a suction passage provided in the peripheral wall of the pump housing, and a discharge port in the hollow chamber. In a vane type pump device comprising a pair of discharge ports communicating with a side first pressure chamber, the discharge ports are mutually connected to each side plate.
The end cover is provided with a second pressure chamber and a detour passage communicating with the first pressure chamber via the same pressure chamber and a discharge passage, and the second pressure chamber is provided on the opposite side of the end cover. The discharge port of the side plate located on the side plate is opened to the first pressure chamber, and the discharge port of the side plate located on the end cover side is opened to the second pressure chamber, so that the pressure fluid discharged from each pressure chamber is It is characterized by providing a difference in length between each passage from the confluence point in the discharge passage to each pressure chamber.

[Functions and effects of the idea]

According to this configuration, the second pressure chamber communicates with the first pressure chamber via the detour passage and the discharge passage, and the pressure fluid discharged from each pressure chamber is connected to the discharge passage from the confluence point in the discharge passage. Since there is a difference between the lengths of the passages up to The two pressure fluids can be brought together by creating a phase difference. As a result, the two pressure fluids cancel each other's pulsations at the confluence point, and the pulsations of the pressure fluid flowing out from the pressure fluid outlet are effectively damped.

In addition, according to this configuration, the bypass passage is located outside the pump housing and is provided in a small end cover that is easy to attach and detach, so by appropriately selecting and using end covers with different lengths of the passage, A pump device that exhibits the best pulsation damping effect can be provided by simple assembly work.
Furthermore, in this configuration, no special members are disposed within the pump device, so the structure is more complex, the device is larger, and the assembly work is more complicated than in normal pump devices of this type. There is no such thing as becoming.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

1 and 2, a hollow chamber 11 with a bottom is formed in the pump housing 10, and this hollow chamber 11 opens at one end of the pump housing 10. As shown in FIG. Inside the hollow chamber 11, there is a rotor 22 that holds a plurality of vanes 21 in a radially slidable manner, and a pair of cam surfaces that accommodate the rotor 22 therein and on which the tips of the vanes 21 slide in contact with the inner circumferential surface of the rotor 22. 14
A cam ring 14 formed symmetrically with a and 14 b oriented at 180 degrees, and a pair of side plates 15 and 1 that are in close contact with both end surfaces of the cam ring 14 and form a plurality of pump chambers partitioned by vanes 21.
The rotor 22, cam ring 14, and side plates 15, 16 are held in place by an end cover 12 fixed to one end of the pump housing 10 by a plurality of tightening bolts 13. This end cover 12 seals the outer open end of the hollow chamber 11 in the pump housing 10 and constitutes one outer end of the housing 10 .

In the above configuration, the rotor 22 is splined to one end of a rotating shaft 24 rotatably supported in the bearing hole 10a of the pump housing 10 via a bearing sleeve 23. The side plate 15 located inside the hollow chamber 11 is formed in a ring shape and is fitted into the bearing hole 10a of the pump housing 10. This side plate 15 is pressed against the cam ring 14 by the elastic force of a coil spring 17 whose one end is locked to the inner wall of the pump housing 10, and as a result, the cam ring 14, the pair of side plates 15, 16, and the end cover 12 come into contact with each other. maintained in the state. Also,
On the surfaces of the pair of side plates 15, 16 that are in contact with the rotor 22, suction ports 25, 26 are provided corresponding to the pump chambers that perform the expansion stroke, and discharge ports 27, 28 are provided that correspond to the boat chambers that perform the compression stroke. are formed respectively. The suction ports 25 and 26 open into an annular groove 29 provided in the hollow chamber 11 so as to surround the cam ring 14. It's communicating.

The first discharge port 27 opens to a first pressure chamber 34 formed inside the hollow chamber 11, and from this first pressure chamber 34 is a throttle passage (not shown) provided in a first discharge passage 35 having a large volume. ), and the first discharge passage 35 is communicated with the bypass passage 33 via a flow rate regulating valve 32 at appropriate times. The second discharge port 28 is provided on the outer side plate 16 in phase with the first discharge port 27 by 180 degrees, and opens into a second pressure chamber 41 formed inside the end cover 12. The second pressure chamber 41 communicates with a detour passage 42 formed in the peripheral wall of the end cover 12, and the detour passage 42 connects to the first discharge passage 35 through a second discharge passage 43 formed in the peripheral wall of the pump housing 10. is connected to. Note that a gain adjustment throttle 44 is interposed in the second discharge passage 43.

With the above configuration, in this embodiment, the pressure fluid discharged from the first discharge port 27 when the pump is operated is discharged into the first pressure chamber 34 and flows into the first discharge passage 35 having a large volume, while the second discharge port 28
The pressure fluid discharged from the second pressure chamber 41 passes through the detour passage 42 and the second discharge passage 43, and then flows into the first pressure chamber 41.
It joins the pressure fluid in the discharge passage 35. In this embodiment, the lengths of the passages from the pressure fluid confluence point in the first discharge passage 35 to the respective pressure chambers 34 and 41 are made different. In addition, in this embodiment, the first
The length of the detour passage 42 can be easily changed by appropriately replacing and using end covers 12 having different dimensions, indicated by the symbol L in the figure.

In this embodiment, arcuate grooves 37 and 38 that open to the back pressure chamber 21a of each vane 21 are provided on the surfaces of the pair of side plates 15 and 16 that are in contact with the cam ring 14.
38 communicates with the first pressure chamber 34 through a through hole 39 bored in the axial direction of the side plate 15, whereby the pressure fluid in the first pressure chamber 34 is applied to each back pressure chamber 21a. It acts to bring the vane 21 into pressure contact with the cam surface of the cam ring 14.
In addition, a pair of positioning pins 19 shown in FIG.
As shown by the two-dot chain line in FIG. 1, 19 is supported between the pump housing 10 and the end cover 12 to phase the cam ring 14 and the pair of side plates 15 and 16.

In the vane type pump device of this embodiment configured as described above, when the volume of the plurality of pump chambers partitioned by each vane 21 changes due to the rotation of the rotor 22, compression is performed in the first compression stroke. The compressed pressure fluid is discharged from the first discharge port 27 to the first pressure chamber 34 and flows into the first discharge passage 35, and the pressure fluid compressed in the second compression stroke is discharged from the second discharge port 28 to the second pressure chamber 34 and flows into the first discharge passage 35. Discharge into chamber 41 and bypass passage 4
2 and the second discharge passage 43 and join the pressure fluid that flowed together. For this reason, the end cover 12
By appropriately determining the length of the detour passage 42 provided in the first discharge passage 35, a phase difference is created between the pressure fluids discharged from both discharge ports 27 and 28, and the two pressure fluids are merged at the first discharge passage 35. be able to.
Therefore, even if the pressure fluid discharged from the first discharge port 27 is pulsating as shown in FIG. 3A,
Since the pulsations of the pressure fluid discharged from the second discharge port 28 occur with a phase period at the merging point as shown by the broken line in FIG. 3B, the pulsations of the merging pressure fluids cancel each other out, The pulsation of the pressure fluid flowing out from the pressure fluid outlet is attenuated as shown in FIG. 3C. Further, when this pump is operated, the pulsation of the pressure fluid discharged from the first discharge port 27 is absorbed in the first discharge passage 35 having a large volume, while the pulsation of the pressure fluid discharged from the second discharge port 28 is absorbed by the second pressure. It is absorbed in the chamber 41 and the detour passage 42, and further the throttle 44 in the second discharge passage 43 is absorbed.
Therefore, the pulsation of the pressure fluid at the merging point can be effectively attenuated by these pulsation absorbing effects.

Furthermore, when implementing the vane type pump device of this embodiment, end covers having different lengths for the detour passage 42 are prepared, and by selecting an appropriate end cover from these end covers, the best one can be obtained. A pump device that exhibits a pulsation damping effect can be provided by simple assembly work.

Furthermore, since the vane type pump device of this embodiment does not employ any special members other than the existing structural members, the structure is more complicated and the device is larger than normal pump devices of this type. There is no possibility that the assembly process will become complicated or complicated.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the vane type pump device of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1,
FIG. 3 is a graph showing the pulsation state of the pressure fluid. Explanation of symbols, 10... Pump housing, 11
... Hollow chamber, 12 ... End cover, 14 ... Cam ring, 15, 16 ... Side plate, 21
... Vane, 22 ... Rotor, 27 ... First discharge port, 28 ... Second discharge port, 34 ... First
Pressure chamber, 35...first discharge passage, 41...second pressure chamber, 42...detour passage, 43...second discharge passage.

Claims (1)

[Scope of utility model registration request] A rotor that holds a plurality of vanes radially is housed, and a cam surface on which the vanes slide is provided on the inner circumferential surface of the rotor.
A cam ring formed symmetrically with a 180° phase, and a pair of side plates that are in close contact with both end surfaces of the cam ring to form a pump chamber defined by each of the vanes are assembled in a hollow chamber of a pump housing, These parts are held in place by an end cover that is fixed to the outer open end of the hollow chamber and constitutes the outer side of one end of the housing, and the side plate has an inlet provided on the peripheral wall of the pump housing. In a vane type pump device comprising a pair of suction ports communicating with the passage and a pair of discharge ports communicating with the first pressure chamber on the discharge side in the hollow chamber, the discharge ports are arranged on each side plate at a phase of 180° with respect to each other. The end cover is provided with a second pressure chamber and a detour passage communicating with the first pressure chamber via the same pressure chamber and a discharge passage, and a side opposite to the end cover is provided. The discharge port of the plate is connected to the first
The discharge port of the side plate, which opens into the pressure chamber and is located on the end cover side, is connected to the second
A vane type pump device that opens into a pressure chamber and has a difference in length between each passage from a confluence point in the discharge passage of pressure fluid discharged from each pressure chamber to each pressure chamber.