Vane pump

Abstract

The invention provides a vane pump which is excellent in sweep effect of vane sliding assistance by using back pressure of other vanes. A vane pump (1) is provided with: a pump housing (10) including a pump chamber (14) demarcated by a cam surface (12); a rotor (20) having an outer peripheral surface (21) facing the cam surface (12), the outer peripheral surface (21) having N slits (22) formed therein; and N blades (30) that are slidably disposed in the N slits (22), respectively. When the number of apex gaps (11) at which the distance between the cam surface (12) and the outer peripheral surface (21) of the rotor (20) is minimum is set as n, the rotor (20) includes communication paths (60) that communicate M slits (22) corresponding to M blades (30) having different phases from each other. N is a non-prime integer, and N is greater than n. M is a prime factor of N, and M is less than N.

Description

Technical Field

[0001] The present disclosure relates to a vane pump. Background Art

[0002] A known vane pump includes: a rotor having an outer peripheral surface facing a cam surface of a pump chamber; and a plurality of vanes disposed in a plurality of slits formed in the outer peripheral surface of the rotor.

[0003] Patent Document 1 describes a vane type compression device in which vanes are freely inserted and retracted in a plurality of vane slits provided in a rotor, and grooves (communication grooves) are provided to connect the vane slits with shaft holes or other vane slits. In the vane type compressor described in Patent Document 1, fluid flows from the shaft hole or other vane slits through the communication groove into the vane slits where negative pressure will be created as the vanes protrude, thereby promoting the protrusion of the vanes. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent No. 5554124 Summary of the invention 1. Technical issues to be resolved

[0005] However, in the vane pump described in Patent Document 1, there is also an unnecessary connecting groove that does not substantially contribute to the sliding assistance of the vanes, and the configuration of the connecting groove does not take into account the phase relationship of the vanes. Therefore, the volume (dead volume) of the connecting groove that does not substantially contribute to the sliding assistance of the vanes will hinder the ripple effect of the sliding assistance of the vanes that utilizes the back pressure of other vanes.

[0006] In view of the above circumstances, an object of at least some embodiments of the present invention is to provide a vane pump having an excellent ripple effect of the sliding assist of the vanes utilizing the back pressure of other vanes. (II) Technical solution

[0007] The vane pump of at least some embodiments of the present invention comprises: a pump housing including a pump chamber defined by a cam surface; a rotor having an outer peripheral surface opposite to the cam surface and having N slits formed on the outer peripheral surface; and N blades, which are respectively slidably arranged in the N slits, and when the number of top gaps with the smallest distance between the cam surface and the outer peripheral surface of the rotor is set to n, the rotor includes a connecting path, which connects M slits corresponding to M blades with different phases from each other, N is a non-prime integer satisfying N>n, and M is a prime factor of N satisfying M<N. (III) Beneficial effects

[0008] In at least some embodiments of the present invention, the number of blades N is a non-prime integer, satisfying N>n, and therefore, there are multiple groups of M blades that establish a phase relationship that can utilize the back pressure of other blades to assist the sliding of the blades. If the M slits corresponding to these M blades are interconnected by a connecting path, multiple groups of M blades that establish a phase relationship that can utilize the back pressure of other blades to assist the sliding of the blades can be formed. In this case, compared with the case where all N slits are interconnected, unnecessary connecting paths that do not substantially contribute to assisting the sliding of the blades that utilize the back pressure of other blades can be omitted, and the dead volume can be reduced. Therefore, the sweep effect of the sliding assist of the blade using the back pressure of other blades can be enhanced, and the followability of the blade can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram showing the internal structure of a vane pump according to an embodiment. Figure 2 This is an axial cross-sectional view of a vane pump according to an embodiment. Figure 3A This is a diagram schematically showing the internal structure of a vane pump according to an embodiment. Figure 3B This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3C This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3D This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3E This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3F This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3G This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3H This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Fig. 3I This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 3J This is a diagram schematically showing the internal structure of a vane pump according to another embodiment. Figure 4A Yes means Figure 3A The perspective view of the structural example of the vane pump shown is a view viewed from the side of one rotor end surface. Figure 4B Yes means Figure 3AThe perspective view of the structural example of the vane pump shown is a view viewed from the other rotor end surface side. Figure 4C Yes means Figure 3A A graph showing the relationship between the lift of the vanes in a vane pump and the angular position of the rotor. Figure 5A Yes means Figure 3D The perspective view of the structural example of the vane pump shown is a view viewed from the side of one rotor end surface. Figure 5B Yes means Figure 3D The perspective view of the structural example of the vane pump shown is a view viewed from the other rotor end surface side. Figure 5C Yes means Figure 3D A graph showing the relationship between the lift of the vanes in a vane pump and the angular position of the rotor. Fig. 6A Yes means Figure 3E The perspective view of the structural example of the vane pump shown is a view viewed from the side of one rotor end surface. Figure 6B Yes means Figure 3E The perspective view of the structural example of the vane pump shown is a view viewed from the other rotor end surface side. Figure 6C Yes means Figure 3E A graph showing the relationship between the lift of the vanes in a vane pump and the angular position of the rotor. Fig. 7A Yes means Figure 3H The perspective view of the structural example of the vane pump shown is a view viewed from the side of one rotor end surface. Figure 7B Yes means Figure 3H The perspective view of the structural example of the vane pump shown is a view viewed from the other rotor end surface side. Figure 7C Yes means Figure 3H A graph showing the relationship between the lift of the vanes in a vane pump and the angular position of the rotor. Figure 8 Yes means Figure 3E A perspective sectional view of a structural example of a rotor of a vane pump shown. Fig. 9 This is an exploded perspective view schematically showing the overall structure of a vane pump according to an embodiment. Description of Reference Numerals 1 (1A ~ 1J) - vane pump; 10 - pump housing; 11 (11A ~ 11B) - top gap; 12 - cam surface; 14 - pump chamber; 20 - rotor; 21 - outer peripheral surface; 22 - slit; 26 - rotor shaft; 28 - shaft hole; 30 - blade; 60 - communication path; 62, 64 - end surface; 66 - communication groove; 68 - communication hole; Gr1 ~ Gr4 - group; N - number of slits (number of blades); M - number of slits connected to each other (number of blades belonging to each group); n - number of top gaps. DETAILED DESCRIPTION

[0010] Some embodiments of the present invention are described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments or shown in the drawings do not limit the scope of the present invention, but are merely illustrative examples. In this specification, unless otherwise specified, "axial direction" and "radial direction" refer to the axial direction and radial direction of the vane pump.

[0011] Figure 1 It is a diagram showing the internal structure of a vane pump according to an embodiment. Figure 2 This is an axial cross-sectional view of a vane pump according to an embodiment.

[0012] In some embodiments, Figure 1 and Figure 2 As shown, the vane pump 1 includes a pump housing 10 , a rotor 20 rotatably provided in the pump housing 10 , and vanes 30 . The vanes 30 are slidably disposed in a plurality of slits 22 formed on the outer peripheral surface of the rotor 20 .

[0013] The pump housing 10 has a pump chamber 14 for accommodating the rotor 20. The pump chamber 14 is defined by a cam surface 12 which is the inner peripheral surface of the pump housing 10. The cam surface 12 is defined by a contour 13 which is a smooth curve. The contour 13 is not circular or is circular. exist Figure 1 In the embodiment shown, the contour 13 is elliptical, and the center of rotation O of the rotor 20 coincides with the center of the ellipse of the contour 13. In another embodiment, the contour 13 is circular, and the center of the circle of the contour 13 is offset relative to the center of rotation O of the rotor 20.

[0014] In some embodiments, Figure 2As shown, the pump housing 10 includes: a first component 10A having a cam surface 12 on the inner circumference, a second component 10B mounted on the first component 10A and closing the opening of the pump chamber 14, and a third component 10C located on the opposite side of the second component 10B across the first component 10A in the axial direction. The first component 10A has a recessed portion that becomes a space for the pump chamber 14, and the inner circumferential wall of the recessed portion of the first component 10A is the cam surface 12. The bottom surface 16 of the recessed portion of the first component 10A extends radially inward from the cam surface 12 along a plane connected to the cam surface 12 and orthogonal to the central axis of the rotor 20. An axial end surface 17 of the second component 10B is opposite to the bottom surface 16 of the recessed portion of the first component 10A across the pump chamber 14 in the axial direction.

[0015] At least one air inlet 40 and at least one air outlet 50 are communicated with the pump chamber 14 . exist Figure 1 In the exemplary embodiment shown, a pair of air inlets 40 (40A, 40B) are connected on both sides of the center O of the rotor 20 on the pump chamber 14, and a pair of air outlets 50 (50A, 50B) are connected on both sides of the center O of the rotor 20. The air inlet 40A and the corresponding air outlet 50A are arranged on both sides across the top gap 11A. Similarly, the air inlet 40B and the corresponding air outlet 50B are arranged on both sides across the top gap 11B. In addition, the top gap 11 (11A, 11B) is the part with the smallest gap between the cam surface 12 of the pump housing 10 and the outer peripheral surface 21 of the rotor 20, which will be described in detail later.

[0016] like Figure 2 As shown, the rotor 20 is connected to a motor (not shown) via a rotor shaft 26, and is configured to be rotatable around a center O in the pump chamber 14. The rotor shaft 26 is fixed to the rotor 20 via an engagement portion 29 in a state of being inserted into a shaft hole 28 provided in the rotor 20. The rotor shaft 26 is rotatably supported by the third member 10C of the pump housing 10 via a bearing 27.

[0017] like Figure 1 and Figure 2 As shown, the rotor 20 has an outer peripheral surface 21, and the outer peripheral surface 21 is defined by a circular contour centered at point O. Figure 1 As shown, in the top gap 11 (11A, 11B), the gap G between the cam surface 12 of the pump housing 10 and the outer peripheral surface 21 of the rotor 20 is the smallest. The number n of the top gaps is an integer greater than 1. Figure 1 In the example, n=2.

[0018] In some embodiments, Figure 1 As shown, N slits 22 are formed on the outer peripheral surface 21 of the rotor 20. N is a non-prime integer and is larger than the number n of the top gaps (ie, satisfies N>n). exist Figure 1 In this example, the number N of the slits 22 is 6, and the six slits 22 are formed on the outer peripheral surface 21 at equal intervals in the circumferential direction of the rotor 20 .

[0019] The extending direction of each slit 22 may be inclined relative to the radial direction of the rotor 20 in the following manner: toward the downstream side in the rotation direction of the rotor 20 as approaching the opening end of the slit 22 on the outer peripheral surface 21 from the end 24 of the slit 22 on the radial inner side of the rotor 20. exist Figure 1 In this example, the rotor 20 rotates counterclockwise, and each slit 22 is inclined relative to the radial direction so as to be directed downstream (counterclockwise) in the rotation direction of the rotor 20 as it approaches the opening end on the outer peripheral surface 21 from the radially inner end 24 .

[0020] N blades 30 are respectively disposed in the N slits 22 , and the blades 30 can reciprocate in the slits 22 . Each vane 30 is pressed against the cam surface 12 of the pump chamber 14 and slides on the cam surface 12 by the centrifugal force generated by the rotation of the rotor 20. The protruding length of each vane 30 from the outer peripheral surface 21 changes periodically according to the rotation phase of the rotor 20. exist Figure 1 In the example, when the six blades 30 pass through a pair of top gaps 11 (11A, 11B) respectively, the protruding length of the blades 30 from the outer peripheral surface 21 is the smallest (can be zero), and at the middle angular position of the pair of top gaps 11 (11A, 11B), the protruding length of the blades 30 from the outer peripheral surface 21 is the largest.

[0021] Between a pair of blades 30 adjacent to each other in the circumferential direction, a cell 15 is defined by the pair of blades 30, the cam surface 12, and the outer peripheral surface 21 of the rotor 20. The number of cells 15 is equal to the number N of blades 30. exist Figure 1 In the illustrated exemplary embodiment, the pump chamber 14 is divided into six compartments 15 by six vanes 30. When a pair of vanes 30 defining the compartments 15 moves circumferentially due to the rotation of the rotor 20, the compartments 15 also move circumferentially and repeat volume reduction and expansion.

[0022] When the compartment 15 reaches the opening position of the air inlet 40 (40A, 40B), the volume of the compartment 15 tends to expand, and gas is taken into the compartment 15 from the air inlet 40. After a period of time, the volume of the compartment 15 will continue to expand as the compartment 15 moves in the circumferential direction, but the volume of the compartment 15 will decrease as the compartment 15 approaches the opening position of the exhaust port 50 (50A, 50B). When the compartment 15 reaches the opening position of the exhaust port 50 (50A, 50B), the volume of the compartment 15 tends to decrease, so the gas in the compartment 15 is discharged from the exhaust port 50. In this way, the gas sucked into the vane pump 1 from the intake port 40 is discharged from the exhaust port 50 .

[0023] exist Figure 1 In the illustrated exemplary embodiment, each blade 30 has a front end surface 31 that is inclined relative to the length direction of the blade 30 (the direction in which the slits 22 extend). The front end surface 31 has a contact portion 33 that contacts the cam surface 12 on the downstream side in the rotation direction of the rotor 20. A portion of the front end surface 31 that is on the upstream side in the rotation direction of the contact portion 33 is set back from the cam surface 12 with respect to the contact portion 33, and a gap is formed between the portion and the cam surface 12. With respect to the blade 30 having such an inclined front end surface 31, the blade length is not constant in the thickness direction of the blade 30, and the blade length increases as it goes toward the downstream side in the rotation direction of the rotor 20.

[0024] In some embodiments, Figure 1 As shown, the rotor 20 includes a plurality of communication paths 60 that communicate with each other the M slits 22 corresponding to the M blades 30 that are different in phase from each other. Each communication path 60 may not communicate with the shaft hole 28. In one embodiment, the communication path 60 is a groove provided in at least one end surface (62, 64) in the axial direction of the rotor 20. Here, the end surface 62 of the rotor 20 is a surface of the rotor 20 facing the bottom surface 16 of the recessed portion of the first member 10A of the pump housing 10, and the end surface 64 of the rotor 20 is a surface of the rotor 20 facing the axial end surface 17 of the second member 10B of the pump housing 10. In another embodiment, the communication path 60 is a communication hole provided inside the rotor 20.

[0025] Next, refer to Figure 3A to Figure 3J , the relationship between the total number N of the slits 22 (blades 30 ), the number n of the top gaps 11 , and the number M of the slits 22 that communicate with each other via the communication paths 60 will be described. Figure 3A to Figure 3J Each of them is a diagram schematically showing the internal structure of the vane pump 1 according to one embodiment.

[0026] In addition, Figure 3A to Figure 3JIn FIG. 1 , in order to distinguish the phase relationship between the groups of M blades 30 corresponding to the M slits 22 connected by the communication paths 60 , the dotted lines of various communication paths 60 are used. The phase relationship between the groups of M blades 30 whose communication paths 60 are represented by the same dotted lines is consistent with each other (however, the phases of the blades 30 in each group are different from each other). In this case, for each of the M blades 30 belonging to one group, there is substantially a blade 30 with the same phase among the M blades 30 belonging to another group. In contrast, the phase relationship between the groups of M blades 30 whose communication paths 60 are represented by different types of dotted lines is offset from each other. In this case, the phase of the M blades 30 belonging to one group as a whole is offset relative to the phase of the M blades 30 belonging to another group. Therefore, for each of the M blades 30 belonging to one group, there is substantially no blade 30 with the same phase among the M blades 30 belonging to the other group.

[0027] In some embodiments, Figure 3A and Figure 3B As shown, the vane pump 1 (1A, 1B) has one top gap 11 (n=1). In the vane pumps 1A and 1B, the pressure around the rotor 20 in the pump chamber 14 is relative to the center O (refer to Figure 1 ) Asymmetric unbalanced vane pump. In the vane pumps 1A and 1B, each vane 30 slides in the slit 22 for one cycle during one rotation of the rotor 20. Specifically, when the vane 30 passes through one top gap 11, most of the vane 30 is accommodated in the slit 22, and when the vane 30 reaches a circumferential position that is geometrically opposite to the top gap 11 across the center O of the rotor 20, the protrusion amount of the vane 30 from the slit 22 is the largest.

[0028] In other embodiments, Figure 3C to Figure 3G As shown, the vane pump 1 (1C to 1G) has two top gaps 11 (n=2). In the vane pumps 1C to 1G, the pressure around the rotor 20 in the pump chamber 14 is relative to the center O (refer to Figure 1 ) is a symmetrical balanced vane pump. In the vane pumps 1C to 1G, each vane 30 slides in the slit 22 for two cycles during one rotation of the rotor 20. Specifically, when the vane 30 passes through each top gap 11, most of the vane 30 is accommodated in the slit 22, and when the vane 30 reaches the circumferential position between the two top gaps 11, the protrusion amount of the vane 30 from the slit 22 is the largest.

[0029] In addition, in other embodiments, Figure 3H to Figure 3J As shown, the vane pump 1 (1H to 1J) has three top gaps 11 (n=3). The vane pumps 1H to 1J are the pressure around the rotor 20 in the pump chamber 14 relative to the center O (refer to Figure 1 ) Asymmetric unbalanced vane pump. In the vane pumps 1H to 1J, each vane 30 slides three cycles in the slit 22 during one rotation of the rotor 20. When the vane 30 passes through each top gap 11, most of the vane 30 is accommodated in the slit 22, and when the vane 30 reaches the circumferential position in the middle of a pair of top gaps 11, the protrusion amount of the vane 30 from the slit 22 is the largest.

[0030] In some embodiments, Figure 3A to Figure 3I In the vane pump 1 (1A to 1D, 1F, 1H, 1I) shown, the total number N of the slits 22 (vanes 30) is a non-prime integer and is larger than the number n of the top gaps 11 (N>n). In addition, the number M of the slits 22 that communicate with each other via the communication path 60 is a prime factor of N, satisfying M<N. exist Figure 3A to Figure 3C , Figure 3E , Figure 3G to Figure 3I In the illustrated vane pump 1 ( 1A to 1C, 1H, 1I), the number M of slits 22 communicating with each other via the communication path 60 is the minimum value of the prime factor of the total number N of slits 22 (vanes 30 ). exist Figure 3D and Figure 3F In the illustrated embodiment, regarding the vane pump 1 (1D, 1F), the minimum value of the prime factors of the total number N of the slits 22 (vanes 30) is a divisor of the number n of the top gaps 11. In addition, the number M of the slits 22 that communicate with each other via the communication path 60 is the minimum value among the prime factors of N excluding the divisors of n.

[0031] exist Figure 3A In the example of the vane pump 1A shown, N = 4, M = 2, and n = 1. The set of prime factors of N is {2}. The set of divisors of n is {1}. Figure 3A In FIG. 1 , a total of two communication paths 60 are distinguished by two dotted lines. In the vane pump 1A, the two groups each consisting of two vanes 30 are shifted in phase with each other.

[0032] exist Figure 3B In the example of the vane pump 1B shown, N = 6, M = 2, n = 1. The set of prime factors of N is {2, 3}. The set of divisors of n is {1}. Figure 3B In FIG. 1 , a total of three communication paths 60 are distinguished by three types of dotted lines. In the vane pump 1B, the phase relationship between the three groups each consisting of two vanes 30 is shifted from each other.

[0033] exist Figure 3CIn the example of the vane pump 1C shown, N = 4, M = 2, n = 2. The set of prime factors of N is {2}. The set of divisors of n is {1, 2}. Figure 3C In FIG. 1 , a total of two communication paths 60 are indicated by the same dotted line. In the vane pump 1C, the phase relationship between the two groups each consisting of two vanes 30 is consistent with each other.

[0034] exist Figure 3D In the example of the vane pump 1D shown, N=6, M=3, n=2. The set of prime factors of N is {2, 3}. The set of divisors of n is {1, 2}. The set of prime factors of N excluding the divisors of n is {3}. Figure 3D In FIG. 1 , a total of four communication paths 60 are indicated by the same dotted lines. In the vane pump 1D, the phase relationship between the two groups each consisting of three vanes 30 is consistent with each other.

[0035] exist Figure 3E In the example of the vane pump 1E shown, N = 8, M = 2, n = 2. The set of prime factors of N is {2}. The set of divisors of n is {1, 2}. Figure 3E In FIG. 1 , a total of four communication paths 60 are distinguished by two types of dotted lines. In the vane pump 1E, for each of the four groups each consisting of two vanes 30, there is one group having the same phase relationship as that group.

[0036] exist Figure 3F In the example of the vane pump 1F shown, N=10, M=5, n=2. The set of prime factors of N is {2, 5}. The set of divisors of n is {1, 2}. The set of prime factors of N excluding the divisors of n is {5}. Figure 3F In FIG. 1 , a total of eight communication paths 60 are indicated by the same dotted lines. In the vane pump 1F, the phase relationship between the two groups each consisting of five vanes 30 is consistent with each other.

[0037] exist Figure 3G In the example of the vane pump 1G shown, N = 12, M = 2, n = 2. The set of prime factors of N is {2, 3}. The set of divisors of n is {1, 2}. Figure 3G In FIG. 1 , a total of six communication paths 60 are distinguished and indicated by three types of dotted lines. In the vane pump 1G, for each of the six groups each consisting of two vanes 30 , there is one group having the same phase relationship as that group.

[0038] exist Figure 3H In the example of the vane pump 1H shown, N = 6, M = 2, n = 3. The set of prime factors of N is {2, 3}. The set of divisors of n is {1, 3}. Figure 3HIn FIG. 1 , a total of three communication paths 60 are indicated by the same dotted lines. In the vane pump 1H, the phase relationship between the three groups each consisting of two vanes 30 is consistent with each other.

[0039] exist Fig. 3I In the example of the vane pump 1I shown, N = 9, M = 3, n = 3. The set of prime factors of N is {3}. The set of divisors of n is {1, 3}. Fig. 3I In FIG. 1 , a total of six communication paths 60 are indicated by the same dotted lines. In the vane pump 1I, the phase relationship between the three groups each consisting of three vanes 30 is consistent with each other.

[0040] exist Figure 3J In the example of the vane pump 1J shown, N = 12, M = 2, n = 3. The set of prime factors of N is {2, 3}. The set of divisors of n is {1, 3}. Figure 3J In FIG. 1 , a total of six communication paths 60 are distinguished by two types of dotted lines. In the vane pump 1J, for each of the six groups of two vanes 30 , there is one group having the same phase relationship as that group.

[0041] Figure 4A and Figure 4B They are perspective views showing a structural example of a vane pump 1A, Figure 4A This is a view from the side of a rotor end face 62. Figure 4B This is a diagram viewed from the other rotor end surface 64 side. Figure 4C 1A is a graph showing the relationship between the protrusion amount (lift amount) of each vane 30 from the slit 22 and the angular position of the rotor 20 in the vane pump 1A. like Figure 4A and Figure 4B As shown, the vane pump 1A has: one top gap 11, four slits 22 (vanes 30), and a total of two communication paths 60, and the communication path 60 connects the two slits 22 corresponding to the two vanes 30 with different phases. In other words, the vane pump 1A satisfies N = 4, M = 2, and n = 1. Figure 4B and Figure 4C As shown, in the vane pump 1A, there are two groups (Gr1, Gr2) of two vanes 30 that move in substantially opposite phases. The two vanes 30 belonging to each group (Gr1, Gr2) slide in the slit 22 for one cycle while substantially maintaining opposite phases to each other during one rotation of the rotor 20 (angle range of 0° to 360°). The phase relationship of the group Gr1 and the group Gr2 as a whole is offset from each other. Therefore, in Figure 3A In FIG. 1 , two communication paths 60 of the vane pump 1A are distinguished by two types of dotted lines. Thus, in the vane pump 1A, a pair of slits 22 corresponding to two vanes 30 whose lift amounts are substantially in opposite phases to each other are connected to each other by the communication path 60. When one slit 22 is about to become negative pressure due to the protrusion of the vane 30, fluid moves through the communication path 60 between the one slit 22 and the other slit 22 that is about to become positive pressure due to the entry of the vane 30. Therefore, the pressure drop of one slit 22 is at least partially offset by the pressure increase of the other slit 22, and the sliding of the vane 30 is promoted.

[0042] Figure 5A and Figure 5B They are perspective views showing a structural example of a vane pump 1D, Figure 5A This is a view from the side of a rotor end face 62. Figure 5B This is a diagram viewed from the other rotor end surface 64 side. Figure 5C 1 is a graph showing the relationship between the protrusion amount (lift amount) of each vane 30 from the slit 22 and the angular position of the rotor 20 in the vane pump 1D. like Figure 5A and Figure 5B As shown, the vane pump 1D has: 2 top gaps 11, 6 slits 22 (vanes 30), and a total of 4 communication paths 60, and the communication paths 60 connect the 3 slits 22 corresponding to the 3 vanes 30 with different phases. In other words, the vane pump 1D satisfies N=6, M=3, and n=2. Figure 5A and Figure 5C As shown, in the vane pump 1D, there are two groups (Gr1, Gr2) of three vanes 30 with a phase difference of about 60° or about 120°. The three vanes 30 belonging to each group (Gr1, Gr2) slide in the slit 22 for two cycles while maintaining a phase difference of about 60° or about 120° during one rotation of the rotor 20 (angle range of 0° to 360°). The phase relationship of the group Gr1 and the group Gr2 as a whole is consistent. Therefore, in Figure 3D In FIG. 1 , six communication paths 60 (two groups) of the vane pump 1D are indicated indiscriminately by one type of dotted line. Thus, in the vane pump 1D, three slits 22 corresponding to three vanes 30 whose lift amounts are shifted by about 60° or about 120° are connected to each other by a total of four communication paths 60 (two in each group Gr1, Gr2). In each group (Gr1, Gr2), when one slit 22 is about to become negative pressure due to the protrusion of the vane 30, fluid moves through the communication path 60 between the one slit 22 and the other two slits 22 that are about to become positive pressure due to the entry of the vane 30. Therefore, the pressure drop in one slit 22 is at least partially offset by the pressure increase in the other two slits 22, and the sliding of the vane 30 is promoted.

[0043] Fig. 6A and Figure 6B They are perspective views showing a structural example of a vane pump 1E, Fig. 6A This is a view from the side of a rotor end face 62. Figure 6B This is a diagram viewed from the other rotor end surface 64 side. Figure 6C 1 is a graph showing the relationship between the protrusion amount (lift amount) of each vane 30 from the slit 22 and the angular position of the rotor 20 in the vane pump 1E. like Fig. 6A and Figure 6B As shown, the vane pump 1E has: 2 top gaps 11, 8 slits 22 (vanes 30), and a total of 4 communication paths 60, and the communication paths 60 connect the two slits 22 corresponding to the two vanes 30 with different phases. In other words, the vane pump 1E satisfies N = 8, M = 4, and n = 2. Figure 6A to Figure 6C As shown, in the vane pump 1E, there are 4 groups (Gr1, Gr2, Gr3, Gr4) of 2 blades 30 that are substantially in opposite phases to each other. The 2 blades 30 belonging to each group (Gr1-Gr4) slide in the slit 22 for 2 cycles while maintaining opposite phases to each other during one rotation of the rotor 20 (angle range of 0° to 360°). The phase relationship of group Gr1 and group Gr2 as a whole group is consistent. The phase relationship of group Gr3 and group Gr4 as a whole group is consistent. In contrast, the phase relationship of group Gr1 (Gr2) and group Gr3 (Gr4) as a whole group is staggered. Therefore, in Figure 3E In the figure, four communication paths 60 of the vane pump 1E are distinguished and represented by two types of dotted lines in groups having different phase relationships. In this way, in the vane pump 1E, a pair of slits 22 corresponding to two vanes 30 whose lift amounts are substantially in opposite phases to each other are connected to each other by the communication path 60. When one slit 22 is about to become negative pressure due to the protrusion of the vane 30, fluid moves through the communication path 60 between the one slit 22 and the other slit 22 that is about to become positive pressure due to the entry of the vane 30. Therefore, the pressure drop of one slit 22 is at least partially offset by the pressure increase of the other slit 22, and the sliding of the vane 30 is promoted.

[0044] Fig. 7A and Figure 7B They are perspective views showing a structural example of a vane pump 1H, Fig. 7A This is a view from the side of a rotor end face 62. Figure 7B This is a diagram viewed from the other rotor end surface 64 side. Figure 7C 1 is a graph showing the relationship between the protrusion amount (lift amount) of each vane 30 from the slit 22 and the angular position of the rotor 20 in the vane pump 1H. like Fig. 7A and Figure 7B As shown, the vane pump 1H has: 3 top gaps 11, 6 slits 22 (vanes 30), and a total of 3 communication paths 60, and the communication paths 60 connect the two slits 22 corresponding to the two vanes 30 with different phases. In other words, the vane pump 1H satisfies N = 6, M = 2, and n = 3. Fig. 7A and Figure 7C As shown, there are three groups (Gr1, Gr2, Gr3) of two blades 30 that move in opposite phases in the vane pump 1H. The two blades 30 belonging to each group (Gr1, Gr2, Gr3) slide in the slit 22 for three cycles while maintaining opposite phases to each other during one rotation of the rotor 20 (angle range of 0° to 360°). The phase relationship of the three groups Gr1 to Gr3 as a whole group is consistent with each other. Therefore, in Figure 3H In the figure, three communication paths 60 (three groups) of the vane pump 1H are indicated without distinction by one dotted line. In this way, in the vane pump 1H, a pair of slits 22 corresponding to two vanes 30 whose lift amounts are substantially in opposite phases to each other are connected to each other through the communication path 60. When one slit 22 is about to become negative pressure due to the protrusion of the vane 30, fluid moves through the communication path 60 between the one slit 22 and the other slit 22 that is about to become positive pressure due to the entry of the vane 30. Therefore, the pressure drop of one slit 22 is at least partially offset by the pressure increase of the other slit 22, and the sliding of the vane 30 is promoted.

[0045] In some embodiments, Figure 4B , Figure 5A , Fig. 6A , Figure 6B , Fig. 7A As shown, each communication path 60 extends linearly between a pair of thin slits 22 among the M thin slits 22 , so that the pair of thin slits 22 are connected. The communication path 60 includes one or more communication grooves 66, and the communication grooves 66 are formed by grooves provided on at least one end surface (62, 64) of the rotor 20 in the axial direction of the vane pump 1. In this case, a plurality of communication grooves 66 may be dispersedly formed on a pair of axial end surfaces 62, 64 of the rotor 20. Fig. 6A and Figure 6B In the illustrated embodiment, the four communication grooves 66 of the vane pump 1E are dispersedly formed in two each of the axial end surfaces 62 and 64 of the rotor 20 . In addition to the communication groove 66, the communication path 60 may also be in the form of a communication hole 68 provided inside the rotor 20. In some embodiments, at least one of the communication paths 60 is a communication hole 68, which extends inside the rotor 20 between a pair of the M slits 22, so that the pair of slits 22 communicate with each other. In the vane pump 1A, as shown in FIG. Figure 4B As shown, the shaft hole 28 does not penetrate the rotor 20, and a connecting hole 68 is provided inside the rotor 20 in the following manner, that is, the connecting hole 68 passes through the axial position between the shaft hole 28 and the end face 64 of the rotor 20. A connecting groove 66 is provided on the end face 64 of the rotor 20 in a direction orthogonal to the connecting hole 68.

[0046] Figure 8 It means Fig. 6A and Figure 6B A perspective cross-sectional view of a structural example of a rotor 20 of a different vane pump 1E. Figure 8 The blades 30 are omitted, only the rotor 20 is shown, and the slits 22 corresponding to the blades 30 of the four groups (Gr1 to Gr4) are marked with reference numerals for identifying the groups. In addition to each communication path 60 being composed of a communication groove 66 or a communication hole 68, Figure 8 The vane pump 1E shown is Fig. 6A and Figure 6B The examples shown are the same. In this Figure 8 In the illustrated embodiment, all four communication paths 60 of the vane pump 1E are formed by communication holes 68. Specifically, a first pair of communication holes 68 connects two pairs of slits 22 at the same axial position, and a second pair of communication holes 68 connects another two pairs of slits 22 at another axial position.

[0047] In some embodiments, Fig. 6A , Figure 6B , Figure 8 As shown, the communication path 60 (first communication path) that connects two of the M slits 22 belonging to the first group (Gr1 or Gr2) to each other passes between any one of the M slits 22 belonging to the second group (Gr3 or Gr4) and the shaft hole 28.

[0048] Fig. 9 It is an exploded perspective view schematically showing the overall structure of a vane pump 1 according to an embodiment. Fig. 9 The vane pump 1 shown by way of example may be a vacuum pump. The vane pump 1 may be, for example, a vane-type electric vacuum pump used to create a negative pressure in a negative pressure chamber of a brake booster in a vehicle such as an automobile. The “upper” and “lower” mentioned below refer to the “upper” and “lower” in a state where the vane pump 1 is installed in a vehicle.

[0049] like Fig. 9 As shown, the vane pump 1 includes a pump housing 10 and a rotor 20 rotatably disposed in the pump housing 10 . The rotor 20 is driven by a motor 80 to rotate around a center O. The motor 80 is disposed below the pump housing 10 .

[0050] The pump housing 10 has a pump chamber 14 for accommodating the rotor 20. The pump chamber 14 is defined by a cam surface 12 which is an inner peripheral surface of the pump housing 10. The cam surface 12 is defined by a circular or non-circular contour 13.

[0051] The rotor 20 has an outer peripheral surface 21, and the outer peripheral surface 21 is defined by a circular contour centered at the point O. A plurality of slits 22 are formed on the outer peripheral surface 21. A vane 30 is provided in each slit 22, and the vane 30 divides the pump chamber 14 into a plurality of compartments 15 (see Figure 1 Each of the thin slits 22 is connected to one or more other thin slits 22 via the communication path 60 . The top gap 11 formed between the cam surface 12 and the outer peripheral surface 21 of the rotor 20 (see Figure 1 ), the total number N of the slits 22 (blades 30), and the number M of the slits 22 interconnected by the communication paths 60, at least satisfy the reference Figure 3A to Figure 7C One of the relationships described.

[0052] exist Fig. 9 In this example, the pump housing 10 includes a pump housing body 70 having a recessed portion forming a bottom surface and a side surface of a pump chamber 14 accommodating the rotor 20 , and a pump cover 72 forming an upper surface of the pump chamber 14 . A top cover 74 is provided above the pump cover 72 to cover the pump cover 72. A bottom cover 76 is provided between the pump casing body 70 and the motor 80 to cover the lower side of the pump casing body 70.

[0053] The bottom cover 76 has an inlet port 90 which is an inlet for air flow toward the pump chamber 14 . The air intake port 90 leads to an air intake passage 93 formed between the pump cover 72 and the top cover 74 via a communication passage 91A provided in the pump housing body 70 and a communication passage 91B provided in the pump cover 72. The communication passage 91B penetrates the pump cover 72, and the gas after passing through the communication passage 91A provided in the pump housing body 70 flows into the air intake passage 93 formed above the pump cover 72 through the communication passage 91B. The air intake passage 93 communicates with the pump chamber 14 (compartment 15) via the air intake port 40 (40A, 40B) provided in the pump cover 72. The intake passage 93 is separated from the exhaust passage 95 described later in a fluid sense by a partition wall 94 provided on the pump cover 72. The intake passage 93 surrounded by the partition wall 94 is connected to the pump chamber 14 (partition chamber 15) via a pair of intake ports 40A and 40B located on opposite sides of the center O of the rotor 20, and extends from the communication path 91B to the opposite side across the center O of the rotor 20 in the radial direction of the rotor 20. Thus, in the top gap 11 (refer to Figure 1 ) takes in gas from the air intake port 90 into the pump chamber 14 (compartment 15) via the air intake port 40 (40A, 40B) opening to the pump chamber 14.

[0054] The pump cover 72 has an exhaust port 92 which is an outlet for the flow of gas exhausted from the pump chamber 14 . The exhaust port 92 is connected to an exhaust passage 95 formed between the pump cover 72 and the top cover 74. As described above, the exhaust passage 95 is separated from the intake passage 93 in a fluid sense by the partition wall portion 94 surrounding the intake passage 93. The pump cover 72 has a communication path 96 connected to the exhaust passage 95. The communication path 96 of the pump cover 72 is connected to the pump chamber 14 (compartment 15) via a communication path 97 and the exhaust port 50 (50A, 50B). The communication path 97 is provided in the pump housing body 70, and the exhaust port 50 (50A, 50B) opens on the bottom surface of the recessed portion of the pump housing body 70 that forms the pump chamber 14. In addition, in Figure 8 Only the top gap 11A is shown (see Figure 1 ) is provided at an exhaust port 50A on the opposite side of the intake port 40A. The gas exhausted from the pump chamber 14 through the exhaust port 50 (50A, 50B) flows in the lateral upper part of the pump chamber 14 through the communication path 97 of the pump housing body 70, and flows into the exhaust passage 95 formed above the pump cover 72 through the communication path 96. Thereafter, the gas in the exhaust passage 95 is exhausted to the outside through the exhaust port 92 communicated with the exhaust passage 95.

[0055] The characteristic structures of the vane pump 1 according to some of the above-mentioned embodiments are summarized as follows.

[0056] [1] At least some embodiments of the vane pump (1) include: a pump housing (10) including a pump chamber (14) defined by a cam surface (12); a rotor (20) having an outer peripheral surface (21) opposite to the cam surface (12), and N slits (22) formed on the outer peripheral surface (21); and N vanes (30) each slidably arranged in the N slits (22), wherein when the number of top gaps (11) at which the distance between the cam surface (12) and the outer peripheral surface (21) of the rotor (20) is minimized is set to n, the rotor (20) includes a connecting path (60) that connects M slits (22) corresponding to M vanes (30) having different phases from each other, wherein N is a non-prime integer satisfying N>n, and M is a prime factor of N satisfying M<N.

[0057] According to the structure of [1] above, the number N of blades (30) is a non-prime integer satisfying N>n, and therefore, there are a plurality of groups (Gr1, Gr2) of M blades (30) that have a phase relationship in which the back pressure of other blades (30) can be used to assist the sliding of the blades (30). If the M slits (22) corresponding to these M blades (30) are interconnected by a connecting path (60), a plurality of groups (Gr1, Gr2) of M blades (30) that have a phase relationship in which the back pressure of other blades (30) can be used to assist the sliding of the blades (30) can be formed. In this case, compared with the case where all N slits are interconnected, unnecessary connecting paths that do not substantially contribute to assisting the sliding of the blades using the back pressure of other blades can be omitted, and the dead volume can be reduced. Therefore, the sweep effect of the sliding assistance of the blade (30) utilizing the back pressure of other blades (30) can be enhanced, and the followability of the blade (30) can be improved.

[0058] [2] In some embodiments, in the structure of [1] above, M is the minimum value of the prime factors of N.

[0059] According to the structure of [2] above, by setting M to the smallest prime factor of N, the number of blades (M) in the group (Gr1 to Gr4) of blades (30) connected between the slits (22) by the connecting path (60) is reduced, the dead volume is further reduced, and the tracking performance of the blades (30) can be more effectively improved.

[0060] [3] In some embodiments, in the structure of [1] or [2] above, the minimum value of the prime factors of N is a divisor of n, and M is the minimum value among the prime factors of N excluding the divisors of n.

[0061] After in-depth research, the inventors found that when the candidate of M, i.e., the minimum value of the prime factors of N, is a divisor of the number n of the top gaps (11), the tracking performance of the blade (30) can be effectively improved by setting M to the minimum value of the prime factors of N excluding the divisors of n. That is, in the above case, compared with setting M to the minimum value of the prime factors of N and giving priority to reducing the dead volume, setting M to the minimum value of the prime factors of N excluding the divisors of n will more clearly obtain the sliding assist effect of the blade (30) utilizing the back pressure of other blades (30) belonging to the same group, thereby being able to improve the effect of improving the tracking performance of the blade (30) as a whole.

[0062] [4] In some embodiments, in any of the structures [1] to [3] above, each communication path (60) extends linearly between a pair of slits (22) among the M slits (22), so that the pair of slits (22) are connected.

[0063] According to the structure of [4] above, it is easier to form the communication path (60) to the rotor (20) than a communication path having a curved shape.

[0064] [5] In some embodiments, in any of the structures of [1] to [4] above, the vane pump (1) includes a rotor shaft (26), the rotor shaft (26) is inserted into an axial hole (28) provided in the rotor (20) and is connected to the rotor (20), and the communication path (60) includes: a first communication path (60) that connects two first slits (22) of the M slits (22) belonging to the first group (Gr1, Gr2) to each other; and a second communication path (60) that connects the two first slits (22) of the M slits (22) belonging to the first group (Gr1, Gr2) to each other. Two second slits (22) among the M slits (22) of the second group (Gr3, Gr4) are connected to each other, and a first connecting path (60) passes between any one of the second slits (22) corresponding to the blades (30) belonging to the second group (Gr3, Gr4) and the shaft hole (28) of the rotor (20) and extends between the two first slits (22) in a manner that the two first slits (22) corresponding to the blades (30) belonging to the first group (Gr1, Gr2) are connected to each other.

[0065] According to the structure of [5] above, it is possible to realize a layout of a first connecting path (60) that is not connected to the second slit (22) and the shaft hole (28) of another group (Gr3, Gr4), which can further reduce the dead volume and more effectively improve the followability of the blade (30).

[0066] [6] In some embodiments, in any of the structures [1] to [5] above, the communication path (60) includes one or more communication grooves (66), and the communication grooves (66) are formed by grooves provided on at least one end face (62, 64) of the rotor (20) in the axial direction of the vane pump (1).

[0067] According to the structure of [6] above, for example, by machining the end surfaces (62, 64) of the rotor (20), a connecting groove (66) that connects the slits (22) corresponding to the M blades (30) can be easily formed.

[0068] [7] In some embodiments, in the structure of [6] above, a plurality of communication grooves (66) are dispersedly formed on a pair of end surfaces (62, 64) of the rotor (20) in the axial direction of the vane pump (1E).

[0069] According to the structure of [7] above, by using a pair of axial end faces (62, 64) of the rotor (20) as the formation site of the connecting groove (66), the layout freedom of the connecting groove (66) is improved.

[0070] [8] In some embodiments, in any of the structures [1] to [7] above, the communication path (60) includes a communication hole (68), and the communication hole (68) extends inside the rotor (20) between a pair of slits (22) among the M slits (22), so that the pair of slits (22) are connected to each other.

[0071] According to the structure of [8] above, the inner region of the rotor (20) is also used as a formation site of the communication path (60), so that the rotor (20) can be made compact. In addition, regarding the formation of the communication hole (68) that connects the fine slits (22) to each other, the communication hole (68) can be formed by machining, electric discharge machining or three-dimensional lamination molding.

[0072] [9] In some embodiments, in any one of the structures [1] to [8] above, a rotor shaft (26) is provided, the rotor shaft (26) is inserted into an axial hole (28) provided in the rotor (20) and is connected to the rotor (20), and the connecting path (60) is not connected to the axial hole (28).

[0073] According to the structure of [9] above, it is possible to prevent the fluid from leaking from the shaft hole (28) via the communication path (60), and to more effectively improve the followability of the blade (30).

[0074] In this specification, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations do not only indicate configurations in a strict sense, but also indicate a state of relative displacement with a tolerance, or at an angle or distance to the extent that the same function can be achieved. For example, expressions such as “same”, “equal”, and “homogeneous” indicating that things are equal do not only indicate a strictly equal state but also indicate a state in which there is a tolerance or a difference to the extent that the same function can be obtained. In the present specification, expressions such as a quadrilateral and a cylindrical shape do not only refer to shapes such as a quadrilateral and a cylindrical shape in a strict geometric sense, but also refer to shapes including concave and convex portions, chamfered portions, etc. within a range that can achieve the same effect. In addition, in this specification, the expression “including”, “comprising”, or “having” one component is not an exclusive expression excluding the presence of other components.

Claims

1. A vane pump comprising: a pump housing containing a pump chamber defined by a cam surface; a rotor having an outer peripheral surface facing the cam surface, and having N slits formed on the outer peripheral surface; and N blades are slidably disposed in the N slits, respectively. When the number of top gaps at which the distance between the cam surface and the outer peripheral surface of the rotor is the smallest is set to n, The rotor includes a communication path that connects M slits corresponding to M blades that are different in phase from each other. N is a non-prime integer, satisfying N>n, M is a prime factor of N, satisfying M<N.

2. The vane pump according to claim 1, characterized in that: M is the minimum value of the prime factors of N.

3. The vane pump according to claim 1 or 2, characterized in that: The smallest of the prime factors of N is a divisor of n, M is the minimum value among the prime factors of N excluding the divisors of n.

4. The vane pump according to claim 1 or 2, characterized in that: Each of the communication paths extends linearly between a pair of thin slits among the M thin slits, so that the pair of thin slits are connected.

5. The vane pump according to claim 1 or 2, characterized in that: A rotor shaft is provided, the rotor shaft being inserted into a shaft hole provided in the rotor and being coupled to the rotor, The communication path includes: a first communication path that connects two first slits among the M slits belonging to the first group to each other; and a second communication path that connects two second slits among the M slits belonging to the second group to each other, The first communication path passes between any one of the second slits and the shaft hole of the rotor and extends between the two first slits so that the two first slits communicate with each other.

6. The vane pump according to claim 1 or 2, characterized in that: The communication path includes one or more communication grooves formed by grooves provided on at least one end surface of the rotor in the axial direction of the vane pump.

7. The vane pump according to claim 6, characterized in that: The plurality of communication grooves are formed dispersedly on a pair of end surfaces of the rotor in the axial direction of the vane pump.

8. The vane pump according to claim 1 or 2, characterized in that: The communication path includes a communication hole extending in the rotor between a pair of the M slits so as to communicate the pair of slits with each other.

9. The vane pump according to claim 1 or 2, characterized in that: A rotor shaft is provided, the rotor shaft being inserted into a shaft hole provided in the rotor and being coupled to the rotor, The communication path is not in communication with the shaft hole.

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