Vane pump

Abstract

To reduce the manufacturing cost of a vane pump.SOLUTION: A vane pump 100 comprises: a rotor 2 connected to a drive shaft 1, and to be rotated and driven; a plurality of vanes 3 provided so as to freely reciprocate in a radial direction with respect to the rotor 2; a cam ring 4 comprising an inner peripheral cam surface 4a with which tip parts 3a of the vanes 3 come into sliding contact in association with the rotation of the rotor 2; and a pump chamber 6 partitioned by the rotor 2, the cam ring 4, and a pair of adjacent vanes 3. In an outer peripheral surface 41 of the cam ring 4, an arc-shaped concave part 41a recessed inward in a radial direction, and having a constant curvature radius, and a cutout part 41b formed continuously with the concave part 41a, and formed in an arc shape having a larger curvature radius than that of the concave part 41a or a linear shape are formed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vane pump.

Background Art

[0002] Patent Document 1 discloses a vane pump including a rotor having a plurality of vanes attached so as to be retractable in the radial direction, a cam ring rotatably accommodating the rotor, and a pump chamber formed between two adjacent vanes and having a volume that changes as the rotor rotates. The cam ring is sandwiched by plate members and its position with respect to the plate members is fixed by positioning pins. A recess for accommodating a part of the positioning pins is formed on the outer peripheral surface of the cam ring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the vane pump as described in Patent Document 1, the cam ring may be formed by sintering. In the cam ring, in order to ensure the strength at the recess, the wall thickness (radial thickness) at the recess is increased. As a result, the periphery of the recess becomes excessively thick, wasting the material of the cam ring and possibly increasing the manufacturing cost of the vane pump.

[0005] The present invention has been made in view of the above problems, and an object thereof is to reduce the manufacturing cost of a vane pump.

Means for Solving the Problems

[0006] The present invention relates to a vane pump, comprising a rotor connected to a drive shaft and rotationally driven, a plurality of vanes provided so as to be reciprocable in the radial direction with respect to the rotor, a cam ring having an inner peripheral cam surface with which the tip of the vane is in sliding contact as the rotor rotates, and a pump chamber defined by the rotor, the cam ring, and a pair of adjacent vanes. The outer peripheral surface of the cam ring is characterized by being formed with an arcuate recess that is recessed radially inward and has a constant radius of curvature, and a notch portion that is formed continuously with the recess and is formed in an arcuate or linear shape having a radius of curvature larger than that of the recess.

[0007] In this invention, the outer peripheral surface of the cam ring has a recess that is recessed radially inward and a notch portion that is formed continuously with the recess. Therefore, for example, the position of the cam ring can be determined by the recess, and the cam ring can be thinned by the notch portion. Thus, waste of the material of the cam ring can be reduced, and the manufacturing cost of the vane pump can be reduced.

[0008] Further, the present invention is characterized in that the notch portion is formed to extend in the tangential direction of the recess from the end of the recess.

[0009] In this invention, since the notch portion is smoothly connected to the recess and the arcuate portion of the outer peripheral surface of the cam ring, stress concentration at the boundary between the notch portion and the recess and at the boundary between the notch portion and the arcuate portion can be reduced.

[0010] Further, the present invention is characterized in that the radial thickness of the notch portion is larger than the thinnest portion of the cam ring in the radial direction.

[0011] In this invention, the strength of the cam ring can be ensured.

Effects of the Invention

[0012] According to the present invention, the manufacturing cost of the vane pump can be reduced.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0014] Hereinafter, with reference to the drawings, a vane pump 100 according to an embodiment of the present invention will be described. The vane pump 100 is used as a fluid pressure supply source for a fluid pressure device 70 (for example, a power steering device, a transmission, etc.) mounted on a vehicle. Here, a fixed displacement type vane pump 100 using hydraulic oil as the working fluid will be described, but other fluids such as working water may be used as the working fluid, and the vane pump 100 may be a variable displacement type.

[0015] FIG. 1 is a cross-sectional view of the vane pump 100, and FIG. 2 is a plan view of the rotor 2, vanes 3, cam ring 4, and body side side plate 30 with the pump cover 20 and cover side side plate 40 removed. Note that FIG. 1 is a cross-section along the line I-I of FIG. 2.

[0016] As shown in FIGS. 1 and 2, the vane pump 100 includes a housing 25, a drive shaft 1 rotatably supported by the housing 25, a rotor 2 connected to the drive shaft 1 and rotationally driven, a plurality of slits 2s opening on the outer peripheral surface of the rotor 2, a plurality of vanes 3 slidably inserted into the slits 2s of the rotor 2 and provided to be reciprocally movable in the radial direction with respect to the rotor 2, and a cam ring 4 having an inner peripheral cam surface 4a with which the tip 3a of the vane 3 (see FIG. 2) is in sliding contact as the rotor 2 rotates. The housing 25 includes a pump body 10 having a housing recess 10A, and a pump cover 20 (see FIG. 1) that covers the housing recess 10A and is fixed to the pump body 10. In the present embodiment, the cam ring 4 is formed by sintering and houses the rotor 2 and the vanes 3.

[0017] The vane pump 100 is driven by a driving device (not shown) such as an engine or an electric motor. As shown in FIG. 1, an insertion hole 15 is formed in the housing 25 so as to penetrate the pump cover 20 and not penetrate the pump body 10. A housing recess 10A having a larger diameter than the insertion hole 15 is formed in the pump body 10. The cam ring 4 housing the rotor 2 and the vanes 3 is housed in the housing recess 10A of the pump body 10, the drive shaft 1 is inserted into the insertion hole 15, and the rotor 2 is connected to the drive shaft 1. The vane pump 100 generates fluid pressure when the rotor 2 is rotationally driven clockwise as shown by the arrow in FIG. 2 as the drive shaft 1 rotates. The drive shaft 1 is rotatably supported by the housing 25 via bushes 11 and 12 provided in the insertion hole 15. A seal member 55 for preventing leakage of hydraulic oil is provided between the outer peripheral surface of the drive shaft 1 and the pump cover 20.

[0018] Hereinafter, the direction along the rotation axis of the rotor 2 (in other words, the drive shaft 1) is referred to as the "axial direction", the radial direction centered on the rotation axis of the rotor 2 is referred to as the "radial direction", and the direction in which the rotor 2 rotates during the operation of the vane pump 100 is referred to as the "circumferential direction".

[0019] As shown in Fig. 1, the vane pump 100 further includes a body side side plate 30 provided on one axial end side of the rotor 2 and in contact with one side surface of the rotor 2 and the cam ring 4, and a cover side side plate 40 provided on the other axial end side of the rotor 2 and in contact with the other side surface of the rotor 2 and the cam ring 4.

[0020] The body side side plate 30 is provided between the bottom surface of the accommodation recess 10A and the rotor 2. One axial end surface (the lower end surface in Fig. 1) of the rotor 2 is in sliding contact with the body side side plate 30, and one axial end surface (the lower end surface in Fig. 1) of the cam ring 4 abuts against the body side side plate 30. The cover side side plate 40 is provided between the rotor 2 and the pump cover 20. The other axial end surface (the upper end surface in Fig. 1) of the rotor 2 is in sliding contact with the cover side side plate 40, and the other axial end surface (the upper end surface in Fig. 1) of the cam ring 4 abuts against the cover side side plate 40.

[0021] The body side side plate 30, the rotor 2, the cam ring 4, and the cover side side plate 40 are accommodated in the accommodation recess 10A of the pump body 10. In this state, when the pump cover 20 is attached to the pump body 10, the accommodation recess 10A is sealed.

[0022] As shown in Fig. 2, a plurality of slits 2s are formed radially in the rotor 2. The slits 2s open to the outer periphery of the rotor 2.

[0023] The vane 3 is formed in a rectangular flat plate shape. The vane 3 is slidably inserted into the slit 2s and has a tip portion 3a which is an end portion in the direction protruding from the slit 2s and a base end portion 3b which is an end portion opposite to the tip portion 3a. In the slit 2s, a back pressure chamber 5 is partitioned by the base end portion 3b of the vane 3. The back pressure chamber 5 communicates with a high pressure chamber 14 as will be described later, and hydraulic oil is led from the high pressure chamber 14 to the back pressure chamber 5. The vane 3 is pressed in the direction of protruding from the slit 2s by the pressure of the hydraulic oil led to the back pressure chamber 5.

[0024] The cam ring 4 is an annular member having an inner circumferential cam surface 4a which is a substantially oval-shaped inner circumferential surface. The inner circumferential cam surface 4a is a surface with which the tip portions 3a of a plurality of vanes 3 are in sliding contact as the rotor 2 rotates.

[0025] The vane 3 is pressed in the direction of protruding from the slit 2s (radially outward) by the fluid pressure in the back pressure chamber 5 that presses the base end portion 3b and the centrifugal force acting as the rotor 2 rotates. When the vane 3 is pressed radially outward, the tip portion 3a of the vane 3 is in sliding contact with the inner circumferential cam surface 4a of the cam ring 4. As a result, inside the cam ring 4, a pump chamber 6 is partitioned by the outer circumferential surface of the rotor 2, the inner circumferential cam surface 4a of the cam ring 4, and a pair of adjacent vanes 3.

[0026] The inner circumferential cam surface 4a is formed in a substantially elliptical shape. Therefore, as the rotor 2 rotates, the volume of the pump chamber 6 repeatedly expands and contracts. In the suction region 81 where the pump chamber 6 expands, the hydraulic oil is sucked in, and in the discharge region 82 where the pump chamber 6 contracts, the hydraulic oil is discharged.

[0027] The cam ring 4 has a pin hole 4b through which the positioning pin 8 is inserted. By inserting the positioning pin 8 through the pin hole 4b and a pin hole (not shown) in the pump cover 20, the cam ring 4 is positioned with respect to the housing 25. Note that the configuration of the outer circumferential surface 41 of the cam ring 4 will be described later.

[0028] As shown in FIG. 1, on the bottom surface side of the accommodation recess 10A of the pump body 10, an annular high-pressure chamber 14 is partitioned by the pump body 10 and the body-side side plate 30. High-pressure hydraulic oil discharged from the pump chamber 6 is guided to the high-pressure chamber 14. The high-pressure chamber 14 is connected to a fluid pressure device 70 (for example, a power steering device, a transmission, etc.) outside the vane pump 100 via a discharge passage 62.

[0029] A low-pressure chamber 21 is formed in the pump cover 20, and a bypass passage 13 communicating with the low-pressure chamber 21 is formed on the inner peripheral surface of the accommodation recess 10A. The low-pressure chamber 21 is connected to the tank 60 via the tank passage 61. The low-pressure chamber 21 and the bypass passage 13 form a suction passage 50 for guiding hydraulic oil to the pump chamber 6 as will be described later.

[0030] As shown in FIGS. 1 and 2, the body-side side plate 30 has a discharge port 31 (see FIG. 2) formed to correspond to the discharge region 82, a through-hole (not shown) through which the drive shaft 1 is inserted, a suction port 33 formed to correspond to the suction region 81, back pressure grooves 34 provided at intervals in the circumferential direction of the rotor 2 and communicating with the back pressure chamber 5, and pin holes (not shown) through which the positioning pins 8 are inserted.

[0031] The discharge port 31 is formed through the body-side side plate 30 and guides the hydraulic oil discharged from the pump chamber 6 to the high-pressure chamber 14. The suction port 33 is formed in a concave shape opening radially outward and guides the hydraulic oil from the bypass passage 13 of the suction passage 50 to the pump chamber 6. The back pressure grooves 34 overlap and communicate with a plurality of back pressure chambers 5 as the rotor 2 rotates. The back pressure grooves 34 are formed through the body-side side plate 30 and communicate with the high-pressure chamber 14. Thereby, the high-pressure hydraulic oil from the discharge port 31 is guided to the back pressure chamber 5 through the high-pressure chamber 14 and the back pressure grooves 34. The back pressure chamber 5 presses the vane 3 toward the inner peripheral cam surface 4a with the hydraulic oil guided through the back pressure grooves 34 and makes the vane 3 slide in contact with the inner peripheral cam surface 4a.

[0032] As shown in FIG. 1, the cover-side side plate 40 has a through-hole (not shown) through which the drive shaft 1 is inserted, a suction port 43 formed to correspond to the suction region 81, and pin holes (not shown) through which the positioning pins 8 are inserted.

[0033] The suction port 43 is formed through the cover-side side plate 40 and guides hydraulic oil from the low-pressure chamber 21 of the suction passage 50 to the pump chamber 6. Thus, hydraulic oil is guided into the pump chamber 6 through the suction port 33 of the body-side side plate 30 and the suction port 43 of the cover-side side plate 40. The body-side side plate 30 and the cover-side side plate 40 are positioned with respect to the housing 25 by the positioning pins 8, similar to the cam ring 4.

[0034] Next, the operation of the vane pump 100 will be described.

[0035] When the drive shaft 1 is rotationally driven by the power of a drive device (not shown) such as an engine, the rotor 2 rotates in the direction indicated by the arrow in FIG. 2. As the rotor 2 rotates, the pump chamber 6 located in the suction region 81 expands. As a result, the hydraulic oil in the tank 60 is sucked into the pump chamber 6 through the tank passage 61, the suction passage 50, the suction port 33 of the body-side side plate 30, and the suction port 43 of the cover-side side plate 40, as shown in FIG. 1. Further, as the rotor 2 rotates, the pump chamber 6 located in the discharge region 82 contracts. As a result, the hydraulic oil in the pump chamber 6 is discharged into the high-pressure chamber 14 through the discharge port 31 (see FIG. 2). The hydraulic oil discharged into the high-pressure chamber 14 is supplied to an external fluid pressure device 70 through the discharge passage 62. In the vane pump 100 of the present embodiment, while the rotor 2 makes one rotation, each pump chamber 6 repeats the suction and discharge of hydraulic oil twice.

[0036] A part of the hydraulic oil discharged into the high-pressure chamber 14 is supplied to the back-pressure chamber 5 through the back-pressure groove 34 and presses the base end portion 3b of the vane 3 toward the inner peripheral cam surface 4a. Therefore, the vane 3 is pressed in the direction of protruding from the slit 2s by the fluid pressure of the back-pressure chamber 5 that presses the base end portion 3b and the centrifugal force acting as the rotor 2 rotates. As a result, the tip portion 3a of the vane 3 rotates while slidingly contacting the inner peripheral cam surface 4a of the cam ring 4, so that the hydraulic oil in the pump chamber 6 is discharged from the discharge port 31 without leaking between the tip portion 3a of the vane 3 and the inner peripheral cam surface 4a of the cam ring 4.

[0037] Next, the configuration of the outer peripheral surface 41 of the cam ring 4 will be described in detail.

[0038] As shown in FIG. 2, on the outer peripheral surface 41 of the cam ring 4, an arc-shaped recess 41a that is recessed radially inward and has a constant radius of curvature, and a notch 41b formed continuously with the recess 41a are formed. In the present embodiment, a pair of the recess 41a and the notch 41b are formed at positions and in shapes that are symmetric with respect to the rotation center axis O (drive shaft 1) of the rotor 2. Other than the recess 41a and the notch 41b on the outer peripheral surface 41 of the cam ring 4, it is formed as an arc portion 41c centered on the rotation center axis O. In other words, the outer peripheral surface 41 of the cam ring 4 is formed in a substantially circular shape centered on the rotation center axis O, and has a space S formed by the recess 41a and the notch 41b being recessed radially inward.

[0039] The recess 41a is formed in an arc shape in the vicinity of the pin hole 4b. In the present embodiment, the recess 41a is formed in the discharge region 82 and is formed in an arc shape with a central angle of approximately 90 degrees. The notch 41b extends from the end portion 41d of the recess 41a to the rear side in the rotation direction of the drive shaft 1. In the present embodiment, the notch 41b is formed linearly in the discharge region 82. Specifically, the notch 41b extends from the end portion 41d of the recess 41a in the tangential direction of the recess 41a and is connected to the arc portion 41c.

[0040] The recess 41a is used, for example, to determine the front - back orientation of the cam ring 4 during the assembly of the vane pump 100. Specifically, as shown in FIG. 3, a cylindrical portion 45 is provided on a jig (not shown) for setting the cam ring 4. The cylindrical portion 45 is arranged in the space S so as to be able to contact the recess 41a. With the cylindrical portion 45 arranged in the space S, the cam ring 4 is rotated in a predetermined direction (in this embodiment, counterclockwise as indicated by the arrow in FIG. 3) so that the recess 41a contacts the outer peripheral surface of the cylindrical portion 45. Thereby, the cam ring 4 is set on the jig. At this time, if the cam ring 4 is upside - down, as shown in FIG. 4, the positional relationship between the recess 41a and the notch portion 41b is reversed. Therefore, even when the cam ring 4 is rotated in a predetermined direction (in this embodiment, counterclockwise as indicated by the arrow in FIG. 4) with the cylindrical portion 45 arranged in the space S, the recess 41a does not contact the outer peripheral surface of the cylindrical portion 45, so that the cam ring 4 cannot be set on the jig. Thus, the recess 41a can determine the front - back orientation of the cam ring 4 during the assembly of the vane pump 100, and the incorrect assembly of the cam ring 4 is prevented.

[0041] Here, in the cam ring 4, in order to ensure the strength at the recess 41a and the pin hole 4b, the wall thickness (thickness in the radial direction) at the recess 41a and the pin hole 4b is increased. If the notch portion 41b is not formed on the outer peripheral surface 41 of the cam ring 4, the periphery of the recess 41a and the pin hole 4b becomes excessively thick, resulting in a large waste of the material of the cam ring 4 formed by sintering, so that the manufacturing cost of the vane pump 100 increases.

[0042] On the other hand, in the vane pump 100 of this embodiment, the outer peripheral surface 41 of the cam ring 4 has a notch portion 41b continuous with the recess 41a formed at a portion with a large wall thickness. Therefore, while thinning the cam ring 4 by the notch portion 41b, the necessary strength of the cam ring 4 can be ensured. Therefore, the waste of the material of the cam ring 4 can be reduced, and the manufacturing cost of the vane pump 100 can be reduced.

[0043] In the cam ring 4, the notch 41b extends from the end 41d of the recess 41a in the tangential direction of the recess 41a and is connected to the arc portion 41c. Therefore, since the notch 41b is smoothly connected to the recess 41a and the arc portion 41c, stress concentration at the boundary (end 41d) between the notch 41b and the recess 41a and at the boundary 41e between the notch 41b and the arc portion 41c can be reduced. Viewed another way, the recess 41a is connected to the arc portion 41c via the notch 41b. Therefore, the stress concentration around the recess 41a can be reduced due to the presence of the notch 41b. Thus, in the vane pump 100, by forming the notch 41b based on the recess 41a that determines the front and back directions of the cam ring 4 and thinning the cam ring 4, it is possible to reduce stress concentration around the recess 41a while ensuring the strength of the cam ring 4.

[0044] Also, in the cam ring 4, the radial thickness of the notch 41b is larger than that of the thinnest portion 41f in the radial direction of the cam ring 4. Specifically, the thinnest portion 41f is the boundary between the transition region 83 between the suction region 81 and the discharge region 82 and the suction region 81 in the cam ring 4. The boundary between the transition region 83 and the suction region 81 has the lowest pressure of the hydraulic oil in the pump chamber 6, and since the pressure received by the cam ring 4 from the hydraulic oil is low, it is the thinnest portion 41f in the radial direction of the cam ring 4. Even if the cam ring 4 is thinned by the notch 41b, since the radial thickness of the notch 41b is larger than that of the thinnest portion 41f, the strength of the cam ring 4 can be ensured.

[0045] According to the above-described embodiment, the following effects are obtained.

[0046] In the vane pump 100, the outer peripheral surface 41 of the cam ring 4 has a recess 41a and a notch 41b formed continuously with the recess 41a. Therefore, while positioning the front and back of the cam ring 4 with the recess 41a, the cam ring 4 can be thinned with the notch 41b. Therefore, waste of the material of the cam ring 4 can be reduced, and the manufacturing cost of the vane pump 100 can be reduced.

[0047] Next, a modification of this embodiment will be described. The following modifications are also within the scope of the present invention, and it is also possible to combine the configurations shown in the modifications with the configurations described in the above-described embodiment, or to combine the configurations described in the following different modifications with each other.

[0048] <Modification 1> In the above embodiment, a pair of the concave portion 41a and the notch portion 41b are formed at symmetric positions and shapes with respect to the drive shaft 1. However, the present invention is not limited to this, and only one concave portion 41a and notch portion 41b may be formed on the outer peripheral surface 41 of the cam ring 4. Even with this configuration, the same effects as those of the above embodiment can be obtained. However, from the viewpoint of reducing waste of the material of the cam ring 4 and reducing the manufacturing cost of the vane pump 100, it is preferable to form a pair of the concave portion 41a and the notch portion 41b.

[0049] <Modification 2> In the above embodiment, the notch portion 41b is formed linearly extending in the tangential direction of the concave portion 41a from the end portion 41d of the concave portion 41a. Thereby, stress concentration at the boundary (end portion 41d) between the notch portion 41b and the concave portion 41a and the boundary 41e between the notch portion 41b and the arc portion 41c can be reduced, and the strength of the cam ring 4 can be improved. However, the above configuration is not essential, and when the strength of the cam ring 4 is sufficient, etc., the notch portion 41b may be formed without extending in the tangential direction of the concave portion 41a from the end portion 41d of the concave portion 41a. Further, the notch portion 41b is not limited to a linear shape, and may be formed in an arc shape having a curvature radius larger than that of the concave portion 41a.

[0050] <Modification 3> In the above embodiment, the radial thickness of the notch portion 41b is larger than that of the thinnest thin portion 41f in the radial direction of the cam ring 4. However, the present invention is not limited to this, and when the strength of the cam ring 4 can be ensured, the notch portion 41b may be the thinnest thin portion in the radial direction of the cam ring 4.

[0051] <Modification Example 4> In the above-described embodiment, the concave portion 41a is used to determine the front-back direction of the cam ring 4 during the assembly of the vane pump 100. However, the use of the concave portion 41a is not limited to this. For example, a configuration may be adopted in which the cam ring 4 is positioned with respect to the housing 25 by inserting a positioning pin 8 through the concave portion 41a. In the case of this configuration, it is not necessary to form a pin hole 4b through which the positioning pin 8 is inserted in the cam ring 4.

[0052] <Modification Example 5> In the above-described embodiment, the vane pump 100 includes a body-side side plate 30 and a cover-side side plate 40. However, the body-side side plate 30 and the cover-side side plate 40 are not essential components of the vane pump 100. Even with this configuration, the same effects as those of the above-described embodiment can be obtained.

[0053] Hereinafter, the configurations, operations, and effects of the embodiments of the present invention will be collectively described.

[0054] The vane pump 100 includes a rotor 2 that is connected to a drive shaft 1 and is rotationally driven, a plurality of vanes 3 that are provided so as to be reciprocally movable in the radial direction with respect to the rotor 2, a cam ring 4 that has an inner peripheral cam surface 4a with which the tip portion 3a of the vane 3 slidably contacts as the rotor 2 rotates, and a pump chamber 6 that is defined by the rotor 2, the cam ring 4, and a pair of adjacent vanes 3. An arc-shaped concave portion 41a that is recessed radially inward and has a constant radius of curvature, and a notch portion 41b that is formed continuously with the concave portion 41a and is formed in an arc shape or a linear shape having a radius of curvature larger than that of the concave portion 41a are formed on the outer peripheral surface 41 of the cam ring 4.

[0055] In this configuration, the outer peripheral surface 41 of the cam ring 4 has a concave portion 41a that is recessed radially inward and a notch portion 41b that is formed continuously with the concave portion 41a. Therefore, for example, the position of the cam ring 4 can be determined by the concave portion 41a, and the cam ring 4 can be thinned by the notch portion 41b. Thus, waste of the material of the cam ring 4 can be reduced, and the manufacturing cost of the vane pump 100 can be reduced.

[0056] Also, in the vane pump 100, the notch portion 41b is formed to extend in a tangential direction of the concave portion 41a from an end portion 41d of the concave portion 41a.

[0057] In this configuration, since the notch portion 41b is smoothly connected to the concave portion 41a and the arc portion 41c of the outer peripheral surface 41 of the cam ring 4, stress concentration at the boundary (end portion 41d) between the notch portion 41b and the concave portion 41a and at the boundary 41e between the notch portion 41b and the arc portion 41c can be reduced.

[0058] Also, in the vane pump 100, the radial thickness of the notch portion 41b is larger than that of the thinnest portion 41f in the radial direction of the cam ring 4.

[0059] In this configuration, the strength of the cam ring 4 can be ensured.

[0060] As described above, the embodiments of the present invention have been described. However, the above embodiments merely show a part of application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Explanation of Reference Numerals

[0061] 1... drive shaft, 2... rotor, 3... vane, 3a... tip portion, 4... cam ring, 4a... inner peripheral cam surface, 6... pump chamber, 41... outer peripheral surface, 41a... concave portion, 41b... notch portion, 41d... end portion, 41f... thinnest portion, 100... vane pump

Claims

1. A rotor connected to a drive shaft and rotationally driven, a plurality of vanes provided so as to be reciprocally movable in the radial direction with respect to the rotor, a cam ring having an inner peripheral cam surface with which the tip of the vane is in sliding contact as the rotor rotates, the rotor, the cam ring, and a pump chamber defined by the pair of adjacent vanes, and on the outer peripheral surface of the cam ring, an arcuate recess that is recessed radially inward and has a constant radius of curvature, and a notch formed continuously with the recess and formed in an arcuate or linear shape having a radius of curvature larger than that of the recess, characterized in that the vane pump is provided.

2. The vane pump according to claim 1, wherein the notch is formed to extend in the tangential direction of the recess from the end of the recess, characterized in that the vane pump is provided.

3. The vane pump according to claim 1, wherein the radial thickness of the notch is larger than the thinnest thin portion in the radial direction of the cam ring, characterized in that the vane pump is provided.

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