Vane pump and its stator

Abstract

The present application discloses a stator (130) of a vane pump, comprising: an inner peripheral surface (131) for defining a hollow space, wherein the hollow space is used to eccentrically mount a rotor (140) of the vane pump, wherein a circumferential groove (132) is formed in the inner peripheral surface (131) in a liquid outlet area of ​​the stator (130), and the axial width of the groove (132) is smaller than the axial width of the inner peripheral surface (131). The present application also discloses a vane pump using the stator.

Description

Technical Field

[0001] The present application relates to a vane pump stator with improved anti-cavitation performance and a vane pump using the stator. Background Art

[0002] Vane pumps are widely used in hydraulic systems as devices for pressurizing fluids. For example, in the fuel injection system of a diesel vehicle, a vane pump can be set as a low-pressure pump or a pre-supply pump for a high-pressure common rail to pressurize the fuel to be supplied to the high-pressure common rail.

[0003] The vane pump generally includes a hollow stator and a rotor eccentrically arranged in the stator. The stator and the rotor are sandwiched by two fixed plates, so that a hollow internal space is defined between them. A liquid inlet groove and a liquid outlet groove are respectively formed on one or both of the two fixed plates, and the liquid inlet groove and the liquid outlet groove only extend along a section of the circumference so as to be able to communicate with the hollow internal space. In addition, a plurality of circumferentially spaced radial grooves are formed on the rotor to respectively accommodate a plurality of linearly slidable blades. A stepped radial through hole is formed in each blade so that a spring can be accommodated between the blade and the corresponding radial groove of the rotor to ensure that the blade can move radially in the radial groove while one end always seals against the inner circumferential surface of the stator. In this way, the aforementioned internal space includes a plurality of mutually separated accommodation spaces along the circumference, wherein each accommodation space is defined by two adjacent blades.

[0004] Due to the eccentric design of the rotor relative to the stator, the volumes of the multiple accommodation spaces will change as the rotor rotates. For a certain accommodation space, the volume changes from large to small during the process of moving from a position communicating with the liquid inlet tank to a position communicating with the liquid outlet tank, thereby sucking a fluid such as fuel from the liquid inlet tank and discharging it from the liquid outlet tank under pressure.

[0005] When a blade moves into the area where the liquid outlet groove is located, the fluid upstream and downstream of the blade has a pressure difference (downstream pressure > upstream pressure), causing the fluid to recoil from downstream to upstream. When the recoil fluid passes through the liquid outlet groove at the blade, the flow cross-sectional area becomes smaller, the flow velocity increases and the fluid pressure decreases, thus forming bubbles. When the blade continues to move forward, the pressure downstream of the blade gradually increases, causing the bubble to burst, resulting in "cavitation". This "cavitation" will cause fatigue defects of the blade and / or the corresponding plate in the long term, affecting the service life and even reducing the working efficiency of the vane pump. Summary of the invention

[0006] In view of the above problems, the present application aims to propose a vane pump stator with improved anti-cavitation performance and a vane pump using the stator.

[0007] According to one aspect of the present application, a stator of a vane pump is provided, comprising:

[0008] An inner peripheral surface for defining a hollow space for eccentrically mounting a rotor of a vane pump, wherein a circumferential groove is formed in the inner peripheral surface in a liquid outlet region of the stator, and the axial width of the groove is smaller than the axial width of the inner peripheral surface.

[0009] According to another aspect of the present application, a vane pump is provided, in particular a vane pump for fuel pressurization, comprising:

[0010] End caps;

[0011] End plate;

[0012] a stator fixedly sandwiched between the end cover and the end plate, the stator having an inner peripheral surface defining a hollow space; and

[0013] A rotor is eccentrically installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and when observed in a cross section perpendicular to the axial direction of the stator, the groove at least partially circumferentially overlaps with the liquid outlet groove formed in the end cover or the end plate.

[0014] According to another aspect of the present application, a vane pump is provided, in particular a vane pump for fuel pressurization, comprising:

[0015] End caps;

[0016] End plate;

[0017] a stator fixedly sandwiched between the end cover and the end plate, the stator having a non-circular or elliptical inner peripheral surface defining a hollow space; and

[0018] A rotor is installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and when observed in a cross section perpendicular to the axial direction of the stator, the groove at least partially circumferentially overlaps with the liquid outlet groove formed in the end cover or the end plate.

[0019] By adopting the technical means of the present application, the "cavitation" phenomenon occurring on the blades of the rotor and / or in the housing of the vane pump can be eliminated or significantly suppressed, thereby increasing the service life of the components and improving the working efficiency of the vane pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects of the present application will be more fully understood from the detailed description below in conjunction with the following drawings. It should be noted that the scales of the drawings may be different for the purpose of clear description, but this will not affect the understanding of the present application. In the drawings:

[0021] Figure 1A Schematically shows an exploded view of a vane pump according to the prior art;

[0022] Figure 1B Schematically shows Figure 1A A cross-sectional view of a vane pump;

[0023] Figure 1C Schematically shows the Figure 1B A cross-sectional view taken along line AA in FIG.

[0024] Figure 2A Schematically shows an exploded view of a vane pump according to an embodiment of the present application;

[0025] Figure 2B Schematically shows Figure 2A A cross-sectional view of a vane pump;

[0026] Figure 2C Schematically shows the Figure 2B A cross-sectional view taken along line AA in FIG.

[0027] Figure 3A Schematically shows an exploded view of a vane pump according to another embodiment of the present application;

[0028] Figure 3B Schematically shows Figure 3A A cross-sectional view of a vane pump; and

[0029] Figure 3C Schematically shows the Figure 3B A cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION

[0030] In the various figures of the present application, features with the same structure or similar functions are represented by the same reference numerals.

[0031] Figure 1A The schematic diagram shows an exploded view of a vane pump 10 according to the prior art. For example, the vane pump 10 includes an end cover 11, an end plate 12, and a stator 13 fixed relative to the end cover 11 and the end plate 12. The stator 13 is designed in a hollow ring shape, especially a circular ring shape. Thus, the vane pump 10 also includes a rotor 14 that is eccentrically arranged in the stator 13 and can rotate. For example, the rotor 14 is mounted on a rotating shaft (not shown) supported by the end plate 12 and driven to rotate.

[0032] See also Figure 1B Due to the eccentric design of the rotor 14 relative to the stator 13, a gap 20 is generated between the outer circumferential surface of the rotor 14 and the inner circumferential surface of the stator 13. The size of the gap 20 changes with the circumferential position of the rotor 14, for example, gradually increases from the minimum gap to the maximum gap, and then gradually decreases from the maximum gap to the minimum gap.

[0033] A plurality of radially extending vane slots 15 are formed in the rotor 14, and the plurality of vane slots 15 are spaced from each other along the circumferential direction. A plurality of vanes 16 are respectively received in the corresponding vane slots 15 in a linearly slidable manner. A through hole 16a is formed in each vane 16, and the through hole 16a is stepped so as to have a large diameter section radially away from the stator 13 and a small diameter section radially close to the stator 13. A spring 17 is accommodated in the large diameter section of the through hole 16a of each vane 16 to apply tension between the rotor 14 and the vane 16. In this way, when the vane pump 10 is assembled in place, it can be ensured that one end of the vane 16 always abuts against the inner circumferential surface of the rotor 13.

[0034] For example, a liquid outlet groove 11a and a liquid inlet groove 11c are formed in a surface of the end cover 11 close to the stator 13. The liquid outlet groove 11a communicates with an outlet end of a vane pump (not shown) provided in the end cover 11, and the liquid inlet groove 11c communicates with an inlet end of a vane pump (not shown) provided in the end cover 11. In particular, the liquid outlet groove 11a includes a transition section 11b. The cross-sectional area of ​​the transition section 11b is smaller than the cross-sectional area of ​​the rest of the liquid outlet groove 11a.

[0035] After the vane pump 10 is assembled in place, the liquid outlet groove 11a and the liquid inlet groove 11c are in communication with the gap 20. Each vane 16 defines a plurality of accommodation spaces in the gap 20. As the rotor 14 rotates along the direction R as shown in FIG. 2 , these accommodation spaces undergo volume changes, thereby continuously sucking and pressurizing the fluid from the inlet end of the vane pump through the liquid inlet groove 11c and then discharging it from the outlet end of the vane pump through the liquid outlet groove 11a.

[0036] During the rotation of the rotor 14, a receiving space between two adjacent blades 16 will communicate with the liquid outlet groove 11a, especially the transition section 11b thereof (eg, Figure 1C When the volume of the fluid contained in the accommodation space changes suddenly, the fluid pressure changes sharply, which causes the cavitation bubbles in the fluid to collapse, and then "cavitation" occurs at the radial distal end of the blade 16 upstream of the accommodation space along the direction R, especially at the position where the through hole 16a is located at the distal end. This "cavitation" phenomenon also occurs at the liquid outlet groove 11a, especially at its transition section 11b.

[0037] In order to eliminate or slow down this "cavitation", refer to the following Figure 2A , 2B 2C explain the vane pump 100 according to one embodiment of the present application.

[0038] The vane pump 100 may be a vane pump used in a diesel vehicle, for example, used as a low-pressure fuel supply pump in a high-pressure common rail system of a diesel vehicle. It is conceivable that the vane pump 100 may be integrated with a high-pressure plunger fuel supply pump of a high-pressure common rail system.

[0039] The vane pump 100 includes an end cover 110, an end plate 120, and a stator 130 fixed relative to the end cover 110 and the end plate 120. The stator 130 is designed in a hollow ring shape, especially a circular ring shape. Thus, the vane pump 100 also includes a rotor 140 eccentrically arranged and rotatable in the stator 130. For example, the rotor 140 is mounted on a rotating shaft (not shown) supported by the end plate 120 and driven to rotate. The rotating shaft can be driven to rotate by the output shaft of a diesel engine, for example.

[0040] See also Figure 2B Due to the eccentric design of the rotor 140 relative to the stator 130, a gap 200 is generated between the outer circumferential surface of the rotor 140 and the inner circumferential surface of the stator 130. The size of the gap 200 changes with the circumferential position of the rotor 140, for example, gradually increases from the minimum gap to the maximum gap, and then gradually decreases from the maximum gap to the minimum gap.

[0041] A plurality of radially extending vane slots 150 are formed in the rotor 140, and the plurality of vane slots 150 are spaced apart from each other along the circumferential direction. A plurality of vanes 160 are respectively received in the corresponding vane slots 150 in a linearly sliding manner. A through hole 160a is formed in each vane 160, and the through hole 160a is stepped so as to have a large diameter section radially away from the stator 130 and a small diameter section radially close to the stator 130. A spring 170 is accommodated in the large diameter section of the through hole 160a of each vane 160 to apply tension between the rotor 140 and the vane 160. In this way, when the vane pump 100 is assembled in place, it can be ensured that one end of the vane 160 always abuts against the inner circumferential surface of the rotor 130.

[0042] For example, a liquid outlet groove 110a and a liquid inlet groove 110c are formed in a surface of the end cover 110 close to the stator 130. The liquid outlet groove 110a communicates with an outlet end of a vane pump (not shown) provided in the end cover 110, and the liquid inlet groove 110c communicates with an inlet end of a vane pump (not shown) provided in the end cover 110. In particular, the liquid outlet groove 110a includes a transition section 110b. The cross-sectional area of ​​the transition section 110b is smaller than the cross-sectional area of ​​the rest of the liquid outlet groove 110a.

[0043] After the vane pump 100 is assembled in place, the liquid outlet groove 110a and the liquid inlet groove 110c are connected to the gap 200. Each vane 160 defines a plurality of accommodation spaces in the gap 200. Figure 2B The rotor 140 shown rotates along the direction R, and the accommodating spaces undergo volume changes, so that the fluid is continuously sucked in and pressurized from the inlet end of the vane pump through the inlet groove 110c and then discharged from the outlet end of the vane pump through the outlet groove 110a.

[0044] It should be noted that in the context of this application, the concept of upstream / downstream is defined based on the direction of rotation of the rotor (exemplified as R in the drawings). Taking the drawings shown as an example, at any point of the rotor, the direction in front of the arrow R in the direction of rotation in the drawings is upstream, and the direction behind is downstream.

[0045] exist Figures 2A to 2C In the illustrated embodiment, the end cover 110 may be fixed to the housing of the high-pressure plunger pump by screws, for example, so that the two are integrated into one body, and thus the outlet end of the vane pump 100 may communicate with the oil inlet port of the high-pressure plunger pump.

[0046] The stator 130 has a groove 132 formed in its inner circumferential surface 131. The groove 132 extends in the circumferential direction of the stator 130. The axial width of the groove 132 is smaller than the axial width of the inner circumferential surface 131. In the context of the present application, the term "axial direction" refers to the extension direction of the central axis around which the rotor 140 rotates or a direction parallel to it.

[0047] In addition, in the context of the present application, after the vane pump 100 is assembled in place, the area of ​​the inner circumferential surface 131 of the stator 130 that overlaps with the position of the liquid outlet groove 110a along the circumferential direction is defined as the liquid outlet area. Therefore, this section of the groove 132 of the stator 130 is formed in the liquid outlet area of ​​the inner circumferential surface 131. In the axial direction, the groove 132 is aligned with the through hole 160a of the vane 160, that is, the radial geometric center axis of the groove 132 coincides with the center axis of the through hole 160a.

[0048] Specific as Figure 2B and 2C As shown, when a blade 160 rotates along the direction R and passes through the transition section 110b of the liquid outlet groove 110a, the fuel in the accommodating space immediately downstream of the blade 160 can be discharged not only into the transition section 110b, but also into the groove 132. In this way, the tendency of the sudden change of the volume of the accommodating space in the liquid outlet area of ​​the fuel stator 130 is alleviated, and the rapid change of the fuel pressure difference is reduced, so that the "cavitation" phenomenon at the radial distal end of the blade 160, especially at the position where the through hole 160a is located at the distal end, and the liquid outlet groove 110a, especially at the transition section 110b, can be alleviated or eliminated.

[0049] According to the embodiment of the present application, when observed in a cross section perpendicular to the axial direction of the stator 130, the starting position of the groove 132 of the stator 130 is located downstream of the starting position of the liquid outlet groove 110a of the end cover 110, especially the transition section 110b thereof, in the rotation direction R of the rotor 140, and the end position of the groove 132 of the stator 130 is consistent with the end position of the liquid outlet groove 110a of the end cover 110 in the circumferential direction. In the context of the present application, the starting position refers to the point position of the corresponding feature that the blade 160 passes first in each rotation when the rotor 140 rotates around its central axis, and the end position refers to the point position of the corresponding feature that the blade 160 passes last in each rotation. The starting position of the groove 132 of the stator 130 is located downstream of the starting position of the liquid outlet groove 110a of the end cover 110, especially the transition section 110b thereof, which means that when the rotor 140 rotates, one blade 160 will first pass the liquid outlet groove 110a of the end cover 110, especially the starting position of the transition section 110b thereof, around the direction R, and then pass the starting position of the groove 132 of the stator 130. The end position of the groove 132 of the stator 130 is consistent with the end position of the liquid outlet groove 110a of the end cover 110 in the circumferential direction, which means that when the rotor 140 rotates, one blade 160 will pass the end position of the groove 132 of the stator 130 and the end position of the liquid outlet groove 110a of the end cover 110 around the direction R at the same time.

[0050] In an alternative embodiment, the cross-sectional opening size of the groove 132 may vary with the circumferential position. For example, the cross-sectional opening of the groove 132 may gradually decrease along the direction R. In addition, the cross-sectional opening of the groove 132 may be a rectangle, a trapezoid, a partial circle, or other suitable shapes.

[0051] Figures 3A to 3C FIG. 1 shows a vane pump 100′ according to another embodiment of the present application. Figures 2A to 2C The vane pump 100 shown is substantially the same as the vane pump 100. Therefore, the features of the vane pump 100' that are the same as the vane pump 100 can be referred to. Figures 2A to 2C shown in the Figures 3A to 3C The Figures 2A to 2C The vane pump 100′ differs from the vane pump 100 only in that the transition section 110b of the end cover 110 is omitted. In the vane pump 100′, as shown in FIG. Figure 3A As shown, the starting position of the liquid outlet groove 110a is Figure 2A The starting point of is located downstream. Figures 2A to 2C The embodiment shown is different, in the Figures 3A to 3CIn the illustrated embodiment, the extension range of the liquid outlet area of ​​the stator 130 in the circumferential direction is greater than the extension range of the liquid outlet groove 110a in the circumferential direction.

[0052] Therefore, according to Figures 3A to 3C In the embodiment shown, when a blade 160 moves to the liquid outlet area of ​​the stator 130, the groove 132 is first connected to the through hole 160a in the blade 160. In this way, the groove 132 can also play a role in Figure 2A The transition section 110b shown has the same effect.

[0053] By adopting the technical solution described in the present application, the "cavitation" phenomenon caused by the rapid change in volume of the fluid such as fuel, especially in the liquid outlet area of ​​the stator 130, can be effectively alleviated or eliminated, thereby increasing the service life of the components of the vane pump.

[0054] Although the liquid inlet groove 110a and the liquid outlet groove 110c are formed in the same end cover 110 in the described embodiment, it should be clear to those skilled in the art that they can also be formed in different components respectively, for example, one is formed in the end cover 110 and the other is formed in the end plate 120.

[0055] It should be clear to those skilled in the art that the end cover 110 and the end plate 120 constitute the housing of the vane pump of the present application, and the stator 130 of the vane pump is fixed relative to the housing, and a liquid inlet groove and a liquid outlet groove are formed in the housing. In other alternative embodiments, the housing of the vane pump is not limited to the form of the end cover 110 and the end plate 120 specifically shown, and housings of other structures are also feasible, as long as the housing of other structures can fixedly receive the stator 130 and define the gap 200 as described above together with the stator 130 and the rotor 140.

[0056] In addition, although the rotor is designed eccentrically relative to the stator in the above-described embodiments, it should be clear to those skilled in the art that the technical solution of the present application can also be used for solutions in which the rotor and stator are designed non-eccentrically. For example, in an alternative vane pump, the inner circumferential surface of the stator is non-circular or elliptical, and the rotor is eccentrically or non-eccentrically installed in the hollow space defined by the inner circumferential surface of the stator. In this case, all the embodiments described in the present application are also applicable to such a vane pump.

[0057] Although the specific embodiments of the present application are described in detail herein, they are provided for the purpose of explanation only and should not be considered to limit the scope of the present application. Various substitutions, changes and modifications may be conceived without departing from the spirit and scope of the present application.

Claims

1. A stator (130) of a vane pump, comprising: An inner circumferential surface (131) for defining a hollow space, the hollow space being used for eccentrically mounting a rotor (140) of a vane pump, wherein a liquid outlet groove (110a) is formed in an end cover or an end plate of the stator (130), the liquid outlet groove (110a) comprising a transition section (110b), and a circumferential groove (132) is formed on the inner circumferential surface (131) of the stator (130) in a liquid outlet area overlapping with the position of the liquid outlet groove (110a) along a circumferential direction. 131), and the axial width of the groove (132) is smaller than the axial width of the inner circumferential surface (131); when observed in a cross section perpendicular to the axial direction of the stator (130), the starting position of the groove of the stator (130) is located downstream of the starting position of the transition section (110b) in the rotation direction (R) of the rotor (140), and the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction.

2. The stator (130) according to claim 1, characterized in that: When viewed in a cross section perpendicular to the axial direction of the stator (130), the groove (132) at least partially overlaps the liquid outlet groove (110a) in the circumferential direction in the liquid outlet region.

3. The stator (130) according to claim 2, characterized in that: The inner peripheral surface (131) is a circular inner peripheral surface.

4. The stator (130) according to claim 2 or 3, characterized in that: The cross-sectional area of ​​the transition section (110b) is smaller than the cross-sectional area of ​​the remaining portion of the liquid outlet groove (110a).

5. A vane pump comprising: End cap (110); End plate (120); A stator (130) is fixedly sandwiched between the end cover (110) and the end plate (120), wherein the stator has an inner peripheral surface (131) defining a hollow space; and A rotor (140) is eccentrically mounted in the hollow space of the stator (130), a liquid outlet groove (110a) is formed in the end cover (110) or the end plate (120), a circumferential groove (132) is formed in the inner circumferential surface (131) of the stator (130), the axial width of the groove (132) is smaller than the axial width of the inner circumferential surface (131), and when viewed in a cross section perpendicular to the axial direction of the stator (130), the groove (132) and the liquid outlet groove (110a) at least partially overlap in the circumferential direction, The liquid outlet groove (110a) comprises a transition section (110b), the cross-sectional area of ​​the transition section (110b) is smaller than the cross-sectional area of ​​the rest of the liquid outlet groove (110a), the starting position of the groove (132) is located downstream of the starting position of the liquid outlet groove (110a) in the rotation direction (R) of the rotor (140), and the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction when observed in a cross section perpendicular to the axial direction of the stator (130).

6. The vane pump according to claim 5, characterized in that: The cross-sectional opening of the groove (132) changes along the rotation direction of the rotor (140).

7. The vane pump according to claim 5 or 6, characterized in that: A plurality of blades (160) capable of radial movement are installed in the rotor (140), the radial distal end of each blade (160) abuts against the inner circumferential surface (131), and a radial through hole (160a) is formed in each blade. As the rotor (140) rotates to a liquid outlet area on the inner circumferential surface (131) of the stator (130) that overlaps with the position of the liquid outlet groove (110a) along the circumferential direction, the radial through hole (160a) can communicate with the groove (132).

8. The vane pump according to claim 5 or 6, characterized in that: The vane pump is a vane pump for fuel pressurization.

9. A vane pump comprising: End caps; End plate; A stator is fixedly sandwiched between the end cover and the end plate, wherein the stator has a non-circular inner peripheral surface defining a hollow space; as well as The rotor is installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and the groove and the liquid outlet groove at least partially overlap in the circumferential direction when viewed in a cross section perpendicular to the axial direction of the stator. The liquid outlet groove (110a) includes a transition section (110b), and when observed in a cross section perpendicular to the axial direction of the stator (130), the starting position of the groove of the stator (130) is located downstream of the starting position of the transition section (110b) in the rotation direction (R) of the rotor (140), and the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction.

10. The vane pump according to claim 9, characterized in that: The vane pump is a vane pump for fuel pressurization.

11. A vane pump, comprising: End caps; End plate; A stator is fixedly sandwiched between the end cover and the end plate, wherein the stator has an elliptical inner peripheral surface defining a hollow space; as well as The rotor is installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and the groove and the liquid outlet groove at least partially overlap in the circumferential direction when viewed in a cross section perpendicular to the axial direction of the stator. The liquid outlet groove (110a) includes a transition section (110b), and when observed in a cross section perpendicular to the axial direction of the stator (130), the starting position of the groove of the stator (130) is located downstream of the starting position of the transition section (110b) in the rotation direction (R) of the rotor (140), and the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction.

12. A vane pump comprising: End caps; End plate; A stator is fixedly sandwiched between the end cover and the end plate, wherein the stator has a non-circular inner peripheral surface defining a hollow space; as well as A rotor installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and when observed in a cross section perpendicular to the axial direction of the stator, the groove and the liquid outlet groove at least partially overlap circumferentially, wherein the liquid outlet groove (110a) includes a transition section (110b), the cross-sectional area of ​​the transition section (110b) is smaller than the cross-sectional area of ​​the liquid outlet groove (110a). The cross-sectional area of ​​the remaining portion of the liquid groove (110a), when observed in a cross section perpendicular to the axial direction of the stator (130), the starting position of the groove (132) is located downstream of the starting position of the liquid outlet groove (110a) in the rotation direction (R) of the rotor (140), and when observed in a cross section perpendicular to the axial direction of the stator (130), the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction.

13. The vane pump according to claim 12, characterized in that: The vane pump is a vane pump for fuel pressurization.

14. A vane pump comprising: End caps; End plate; A stator is fixedly sandwiched between the end cover and the end plate, wherein the stator has an elliptical inner peripheral surface defining a hollow space; as well as A rotor installed in the hollow space of the stator, a liquid outlet groove is formed in the end cover or the end plate, a circumferential groove is formed in the inner circumferential surface of the stator, the axial width of the groove is smaller than the axial width of the inner circumferential surface, and when observed in a cross section perpendicular to the axial direction of the stator, the groove and the liquid outlet groove at least partially overlap circumferentially, wherein the liquid outlet groove (110a) includes a transition section (110b), the cross-sectional area of ​​the transition section (110b) is smaller than the cross-sectional area of ​​the liquid outlet groove (110a). The cross-sectional area of ​​the remaining portion of the liquid groove (110a), when observed in a cross section perpendicular to the axial direction of the stator (130), the starting position of the groove (132) is located downstream of the starting position of the liquid outlet groove (110a) in the rotation direction (R) of the rotor (140), and when observed in a cross section perpendicular to the axial direction of the stator (130), the end position of the groove (132) of the stator (130) is consistent with the end position of the liquid outlet groove (110a) in the circumferential direction.

Images