Pump

Abstract

To provide a pump capable of suppressing sealing property reduction of a housing.SOLUTION: In a pump, a housing comprises a housing body and a lid member. The housing body includes a first cylindrical part. The first cylindrical part is opened on one side in a predetermined direction. The lid member includes a lid part closing the opening of the first cylindrical part, a second cylindrical part enclosing the first cylindrical part, an annular part protruding radially outside from an end in the predetermined direction, and a plurality of claws extending from an outer edge in a radial direction of the annular part to the other side in the predetermined direction. A seal member is provided between the first cylindrical part and the second cylindrical part. Each of the plurality of claws includes an arm extending from the annular part to the other side in the predetermined direction and a claw body which is hooked from the other side in the predetermined direction to the housing body. In the annular part, a plurality of through holes is provided which penetrate the annular part in the predetermined direction. The claw bodies in the plurality of claws are respectively positioned on the other side of the plurality of through holes in the predetermined direction. The entire claw body overlaps the through hole respectively in a view in the predetermined direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pump. [Background technology]

[0002] BACKGROUND ART A structure is known in which a cover and a base of a housing that accommodates electrical components are fixed by snap-fitting (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 224720 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described structure, when the cover and base are snap-fitted together, the parts that make up the snap-fit ​​structure elastically deform, which could cause the parts of the cover and base that are sealed by the sealing member to deform, potentially reducing the sealing ability between the cover and base.

[0005] In view of the above circumstances, one object of the present invention is to provide a pump having a structure that can prevent a deterioration in the sealing performance of the housing. [Means for solving the problem]

[0006] One embodiment of the pump of the present invention includes a rotatable rotor, a stator facing the rotor across a gap, a pump mechanism connected to the rotor, and a housing that accommodates the rotor, the stator, and the pump mechanism. The housing includes a housing main body and a cover member fixed to the housing main body. The housing main body has a first cylindrical portion surrounding an imaginary axis extending in a predetermined direction. The first cylindrical portion opens on one side in the predetermined direction. The cover member includes a cover portion that closes the opening of the first cylindrical portion, a second cylindrical portion surrounding the first cylindrical portion, an annular portion that protrudes radially outward from an end of the second cylindrical portion on the other side in the predetermined direction, and a plurality of claws that extend from the radial outer edge of the annular portion to the other side in the predetermined direction and are spaced apart in the circumferential direction around the imaginary axis. A seal member is provided between the first cylindrical portion and the second cylindrical portion. Each of the plurality of claw portions has an arm portion extending from the annular portion to the other side in the predetermined direction, and a claw main body portion protruding radially inward from the arm portion and hooked onto the housing main body from the other side in the predetermined direction. The annular portion is provided with a plurality of through holes that penetrate the annular portion in the predetermined direction and are arranged at intervals in the circumferential direction. The claw main body portions of the plurality of claw portions are respectively located on the other side of the plurality of through holes in the predetermined direction and are arranged opposite each of the through holes in the predetermined direction. The entirety of each of the claw main bodies overlaps with each of the through holes when viewed in the predetermined direction. [Effects of the Invention]

[0007] According to one aspect of the present invention, in a pump, deterioration of the sealing performance of a housing can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a pump according to one embodiment. [Figure 2] FIG. 2 is a partial cross-sectional view of a pump according to one embodiment. [Figure 3]FIG. 3 is a cross-sectional view showing a portion of a pump in one embodiment. [Figure 4] FIG. 4 is a cross-sectional perspective view showing a part of the cover member in one embodiment. [Figure 5] FIG. 5 is a top view of a portion of a pump according to one embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a part of a pump according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] In each figure, the central axis J of the pump in the following embodiments is shown as appropriate. In the following description, the direction in which the central axis J extends is referred to as the "axial direction," the radial direction centered on the central axis J is simply referred to as the "radial direction," and the circumferential direction centered on the central axis J is simply referred to as the "circumferential direction." In each figure, the Z axis parallel to the axial direction is shown. In the following description, the side in the axial direction toward which the arrow of the Z axis points (+Z side) is referred to as the "upper side," and the side opposite to the side toward which the arrow of the Z axis points (-Z side) is referred to as the "lower side." In addition, the outer side in the radial direction is referred to as the "radially outer side," and the inner side in the radial direction is referred to as the "radially inner side."

[0010] In the following embodiments, the central axis J corresponds to a virtual axis extending in a predetermined direction. In other words, the axial direction in which the central axis J extends corresponds to the "predetermined direction." The radial direction about the central axis J corresponds to a radial direction about the virtual axis. The circumferential direction about the central axis J corresponds to a circumferential direction about the virtual axis. In the following embodiments, the upper side corresponds to "one side in the predetermined direction," and the lower side corresponds to "the other side in the predetermined direction." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positions of the various parts, and the actual relative positions may be other than those indicated by these names.

[0011] The pump 100 of this embodiment shown in FIG. 1 is, for example, an electric pump mounted on a vehicle. The pump 100 pumps oil as a fluid. The fluid pumped by the pump 100 is not particularly limited and may be, for example, water. As shown in FIG. 2, the pump 100 includes a motor unit 10, a pump mechanism 20, a housing 30, and a circuit board 40. The motor unit 10, the pump mechanism 20, and the circuit board 40 are housed inside the housing 30.

[0012] The motor unit 10 has a rotor 11 and a stator 12. That is, the pump 100 is equipped with the rotor 11 and the stator 12. The rotor 11 is rotatable about a central axis J. The rotor 11 has a shaft 11a and a rotor body 11b. The shaft 11a is cylindrical and extends axially about the central axis J. The rotor body 11b is fixed to the outer peripheral surface of the shaft 11a. Although not shown, the rotor body 11b has a rotor core and a magnet. The stator 12 faces the rotor 11 across a gap. In this embodiment, the stator 12 is located radially outward of the rotor 11. The stator 12 has a stator core 12a and multiple coils 12b. The multiple coils 12b are attached to the stator core 12a, for example, via insulators (not shown).

[0013] The pump mechanism 20 is connected to the rotor 11. More specifically, the pump mechanism 20 is connected to the lower end of the shaft 11a. In this embodiment, the pump mechanism 20 is a trochoid pump mechanism having an inner rotor 21 and an outer rotor 22. The inner rotor 21 is connected to the shaft 11a. The inner rotor 21 rotates together with the shaft 11a around the central axis J. The outer rotor 22 surrounds the inner rotor 21 from the radially outside. The outer rotor 22 meshes with the inner rotor 21. The outer rotor 22 rotates as the inner rotor 21 rotates.

[0014] The circuit board 40 is located above the motor unit 10. In this embodiment, the plate surface of the circuit board 40 faces the axial direction. The coil 12b of the stator 12 is electrically connected to the circuit board 40 via a conductive member 12c. The conductive member 12c may be a lead wire formed by the end of a conductive wire that forms the coil 12b, or may be a member separate from the coil 12b. Although not shown, the circuit board 40 is provided with an inverter circuit that supplies power to the coil 12b. In this embodiment, the circuit board 40 is fixed to a cover member 60, which will be described later.

[0015] The housing 30 accommodates the rotor 11, the stator 12, the pump mechanism 20, and the circuit board 40. The housing 30 has a housing main body 50 and a cover member 60. As shown in FIGS. 1 and 2, the housing main body 50 is a cylindrical member that opens upward. In this embodiment, the housing main body 50 is a multi-stage cylindrical member that is centered on a central axis J and opens upward. In this embodiment, the housing main body 50 is made of metal. The housing main body 50 may also be made of resin.

[0016] As shown in FIG. 2 , the housing main body 50 has a first circumferential wall portion 51, a second circumferential wall portion 52, a third circumferential wall portion 53, and a fourth circumferential wall portion 54. The first circumferential wall portion 51, the second circumferential wall portion 52, the third circumferential wall portion 53, and the fourth circumferential wall portion 54 are connected in this order from top to bottom. In this embodiment, the first circumferential wall portion 51, the second circumferential wall portion 52, the third circumferential wall portion 53, and the fourth circumferential wall portion 54 are substantially cylindrical and centered on the central axis J. The first circumferential wall portion 51 surrounds the circuit board 40 from the radial outside. The second circumferential wall portion 52 surrounds the motor portion 10 from the radial outside. The third circumferential wall portion 53 surrounds the pump mechanism 20 from the radial outside. The outer diameter of the second circumferential wall portion 52 is smaller than the outer diameter of the first circumferential wall portion 51. The outer diameter of the third circumferential wall portion 53 is smaller than the outer diameter of the second circumferential wall portion 52. The outer diameter of the fourth circumferential wall portion 54 is smaller than the outer diameter of the third circumferential wall portion 53. The upper end of the first circumferential wall portion 51 is the upper end of the housing main body 50. The lower end of the fourth circumferential wall portion 54 is the lower end of the housing main body 50.

[0017] The first peripheral wall portion 51 has a first cylindrical portion 51a and a base portion 51b. The first cylindrical portion 51a surrounds the central axis J. The upper end of the first cylindrical portion 51a is the upper end of the housing main body 50. The first cylindrical portion 51a opens upward. As shown in FIG. 3, a groove 51c is provided on the radially outer surface of the first cylindrical portion 51a. The groove 51c is recessed radially inward from the radially outer surface of the first cylindrical portion 51a. The groove 51c has an annular shape surrounding the central axis J. More specifically, the groove 51c has an annular shape centered on the central axis J. At least a portion of a sealing member 70 (described later) is accommodated in the groove 51c.

[0018] The base 51b is connected to the lower side of the first cylindrical portion 51a. The outer diameter of the base 51b is larger than the outer diameter of the first cylindrical portion 51a. A step portion 55 having an upward-facing step surface 55a is provided between the radially outer surface of the base 51b and the radially outer surface of the first cylindrical portion 51a. The step surface 55a is perpendicular to the axial direction. The step surface 55a is annular and surrounds the central axis J. The radially inner end of the step surface 55a is connected to the lower end of the radially outer surface of the first cylindrical portion 51a.

[0019] An annular groove 51d surrounding the central axis J is provided on the radially outer surface of the base 51b. The annular groove 51d is an annular groove centered on the central axis J. The annular groove 51d is recessed radially inward from the radially outer surface of the base 51b. A portion of the base 51b above the annular groove 51d is a hook portion 56. The hook portion 56 protrudes radially outward from a groove bottom surface 51e located radially inward on the inner surface of the annular groove 51d. In this embodiment, the groove bottom surface 51e is perpendicular to the radial direction. The hook portion 56 has an inclined surface 56a, a flat surface 56b, and a hook surface 56c.

[0020] The inclined surface 56a is part of the radially outer surface of the hook portion 56. The inclined surface 56a is positioned radially outward as it extends downward. The upper end of the inclined surface 56a is connected to the radially outer end of the stepped surface 55a. The flat surface 56b is part of the radially outer surface of the hook portion 56. The upper end of the flat surface 56b is connected to the lower end of the inclined surface 56a. The flat surface 56b is a surface perpendicular to the radial direction. The axial dimension of the flat surface 56b is smaller than the axial dimension of the inclined surface 56a.

[0021] The hooking surface 56c is the lower surface of the hooking portion 56 that protrudes radially outward beyond the groove bottom surface 51e. The hooking surface 56c faces downward. In this embodiment, the hooking surface 56c is perpendicular to the axial direction. The hooking surface 56c is the upper surface of the inner surface of the annular groove 51d. The radially outer end of the hooking surface 56c is connected to the lower end of the flat surface 56b.

[0022] As shown in FIG. 2, the lid member 60 is fixed to the housing main body 50. In this embodiment, the lid member 60 is fixed to the housing main body 50 by a snap-fit ​​structure. The lid member 60 is located on the upper side of the housing main body 50. The lid member 60 closes the upper opening of the housing main body 50, i.e., the upper opening of the first cylindrical portion 51a. In this embodiment, the lid member 60 is made of resin. The lid member 60 is molded as a single member by a molding method using a mold, such as injection molding. The lid member 60 may also be made of metal.

[0023] The lid member 60 has a lid portion 61, a second cylindrical portion 62, an annular portion 63, and a plurality of claw portions 64. The lid portion 61 closes the upper opening of the first cylindrical portion 51a. The lid portion 61 has a first lid wall portion 61a and a second lid wall portion 61b. The first lid wall portion 61a is plate-shaped with its plate surface facing the axial direction. A support portion 61c that supports the circuit board 40 is provided on the lower surface of the first lid wall portion 61a. As shown in FIG. 1 , in this embodiment, the first lid wall portion 61a is substantially disk-shaped and centered on the central axis J. The second lid wall portion 61b is located radially outward of the first lid wall portion 61a. The second lid wall portion 61b is plate-shaped with its plate surface facing the axial direction. In this embodiment, the second lid wall portion 61b is annular and centered on the central axis J. The second lid wall portion 61b is located below the first lid wall portion 61a.

[0024] The second cylindrical portion 62 protrudes downward from the radial outer edge of the cover portion 61. The second cylindrical portion 62 is cylindrical and opens downward. In this embodiment, the second cylindrical portion 62 is cylindrical and has a center on the central axis J. As shown in FIG. 2, the second cylindrical portion 62 is located radially outside the first cylindrical portion 51a and surrounds the first cylindrical portion 51a. The radially inner surface of the second cylindrical portion 62 faces the radially outer surface of the first cylindrical portion 51a. As shown in FIG. 3, the lower end of the second cylindrical portion 62 contacts the stepped surface 55a.

[0025] A seal member 70 is provided between the first cylindrical portion 51a and the second cylindrical portion 62. The seal member 70 has an annular shape surrounding the first cylindrical portion 51a. In this embodiment, the seal member 70 has an annular shape centered on the central axis J. In this embodiment, the seal member 70 is an O-ring. At least a portion of the seal member 70 is housed inside the groove 51c. In this embodiment, almost the entire seal member 70 is housed inside the groove 51c. In an elastically deformed state, the seal member 70 contacts the inner surface of the groove 51c provided in the first cylindrical portion 51a and the radially inner surface of the second cylindrical portion 62. In this way, the seal member 70 seals the gap between the first cylindrical portion 51a and the second cylindrical portion 62. The seal member 70 can prevent water and other contaminants from entering the housing 30 through a gap between the housing main body 50 and the cover member 60.

[0026] 3, the seal member 70 is positioned inside the groove 51c, biased downward. In the example of Fig. 3, the seal member 70 is located below an upper surface of the inner surface of the groove 51c, and is in contact with a radially inner surface of the inner surface of the groove 51c and a lower surface 51f.

[0027] A gap is provided radially between the radially outer surface of the first cylindrical portion 51a and the radially inner surface of the second cylindrical portion 62. That is, in the present embodiment, the first cylindrical portion 51a is loosely fitted into the second cylindrical portion 62. Therefore, a portion of the seal member 70, which is provided between the first cylindrical portion 51a and the second cylindrical portion 62 in an elastically deformed state, can escape into the gap between the radially outer surface of the first cylindrical portion 51a and the radially inner surface of the second cylindrical portion 62. This prevents the seal member 70 from being damaged by excessive pressure when the seal member 70 elastically deforms. Therefore, the seal member 70 can more effectively seal the gap between the first cylindrical portion 51a and the second cylindrical portion 62. In the example of FIG. 3 , a portion of the seal member 70 is provided in a portion of the radial gap between the radially outer surface of the first cylindrical portion 51a and the radially inner surface of the second cylindrical portion 62, which is located below the groove 51c. The sealing member 70 may be elastically deformed in any manner within the groove 51c as long as it can seal the gap between the first cylindrical portion 51a and the second cylindrical portion 62.

[0028] The annular portion 63 protrudes radially outward from the lower end of the second cylindrical portion 62. As shown in FIG. 1, the annular portion 63 has a first annular wall portion 63a and a second annular wall portion 63b. The first annular wall portion 63a protrudes radially outward from the lower end of the second cylindrical portion 62. The first annular wall portion 63a has an annular shape surrounding the central axis J. As shown in FIG. 3, a lower surface of the radially inner portion of the first annular wall portion 63a contacts the stepped surface 55a. The second annular wall portion 63b protrudes downward from the radially outer edge portion of the first annular wall portion 63a. As shown in FIG. 1, the second annular wall portion 63b has an annular shape surrounding the central axis J. More specifically, the second annular wall portion 63b has an annular shape centered on the central axis J. The axial dimension of the second annular wall portion 63b is smaller than the radial dimension of the first annular wall portion 63a.

[0029] As shown in FIG. 4, the connecting portion where the lower surface of the first annular wall portion 63a and the radially inner surface of the second annular wall portion 63b are connected has a curved surface 63c. Therefore, the curved surface 63c can distribute and receive stress at the connecting portion between the first annular wall portion 63a and the second annular wall portion 63b. This prevents damage to the connecting portion between the first annular wall portion 63a and the second annular wall portion 63b. The curved surface 63c is positioned downward as it extends radially outward. The curved surface 63c is concave upward and radially outward. The curved surface 63c is provided over the entire circumferential direction of the connecting portion where the lower surface of the first annular wall portion 63a and the radially inner surface of the second annular wall portion 63b are connected, except for a portion where a through hole 65 (described later) is provided.

[0030] 3, the upper surface of the annular portion 63 is located below the groove 51c. In other words, the lower surface 51f of the inner surface of the groove 51c is located above the upper surface of the annular portion 63. In this embodiment, the upper surface of the annular portion 63 is the upper surface of the first annular wall portion 63a.

[0031] The annular portion 63 is provided with a plurality of through holes 65 that penetrate the annular portion 63 in the axial direction. In this embodiment, the plurality of through holes 65 are provided in the first annular wall portion 63a. The plurality of through holes 65 penetrate the first annular wall portion 63a in the axial direction. As shown in FIG. 5 , the plurality of through holes 65 are arranged at intervals in the circumferential direction. The plurality of through holes 65 are arranged at equal intervals around the circumference in the circumferential direction. In this embodiment, each through hole 65 extends in the circumferential direction. The circumferential dimension of each through hole 65 is larger than the radial dimension of each through hole 65. Each through hole 65 has a substantially rectangular shape with rounded corners when viewed in the axial direction. In other words, the inner edge of the through hole 65 has corners 65a formed by curves when viewed in the axial direction. Therefore, stress can be distributed and received at the corners 65a of the through holes 65. This prevents the annular portion 63 from being damaged. In this embodiment, the four corners of the through-hole 65 are corners 65a that are all formed by curved lines.

[0032] The annular portion 63 has a connecting portion 66 located between circumferentially adjacent through holes 65 of the annular portion 63. In this embodiment, the annular portion 63 is provided on the first annular wall portion 63a. A plurality of connecting portions 66 are provided at intervals in the circumferential direction. The plurality of connecting portions 66 are arranged at equal intervals around the circumference. Both circumferential edges of the connecting portion 66 are respectively formed by the circumferential edge of the through hole 65 adjacent to one circumferential side of the connecting portion 66 and the circumferential edge of the through hole 65 adjacent to the other circumferential side of the connecting portion 66. As shown in FIG. 1 , the connecting portion 66 radially connects the upper end of the second annular wall portion 63b and the lower end of the second cylindrical portion 62. In this embodiment, the circumferential dimension of the connecting portion 66 is smaller than the circumferential dimension of the through holes 65. The number of connecting portions 66 is the same as the number of through holes 65.

[0033] The plurality of claw portions 64 extend downward from the radial outer edge of the annular portion 63. In this embodiment, the plurality of claw portions 64 extend downward from the second annular wall portion 63b. The plurality of claw portions 64 are arranged at intervals in the circumferential direction. The plurality of claw portions 64 are arranged at equal intervals around one circumferential circumference. The number of claw portions 64 is the same as the number of through holes 65 and the number of connecting portions 66. Each claw portion 64 is provided at the same position in the circumferential direction as each of the through holes 65. Each of the plurality of claw portions 64 has an arm portion 64a and a claw main body portion 64b.

[0034] The arm portion 64a extends downward from the annular portion 63. In this embodiment, the arm portion 64a extends downward from the lower end of the second annular wall portion 63b. The radially outer surface of the arm portion 64a is located at the same radial position as the radially outer surface of the second annular wall portion 63b. The radially outer surface of the arm portion 64a is connected without a step to the lower side of the radially outer surface of the second annular wall portion 63b. The arm portion 64a is elastically deformable in the radial direction with its upper end connected to the annular portion 63 as a fulcrum. The circumferential dimension of the arm portion 64a is larger than the circumferential dimension of the connecting portion 66 and smaller than the circumferential dimension of the through-hole 65. In this embodiment, the circumferential dimension of the arm portion 64a decreases downward. As shown in FIG. 3, the radially inner surface of the arm portion 64a contacts, for example, the flat surface 56b of the hook portion 56. The radially inner surface of the arm portion 64a may face the flat surface 56b with a gap therebetween.

[0035] The claw main body portion 64b protrudes radially inward from the arm portion 64a. In this embodiment, the claw main body portion 64b protrudes radially inward from the lower end of the arm portion 64a. The claw main body portion 64b may protrude radially inward from a portion of the arm portion 64a that is above the lower end. The claw main body portion 64b is inserted into the annular groove 51d from the radially outer side. The claw main body portion 64b has an opposing surface 64c facing upward. The opposing surface 64c is perpendicular to the axial direction. The opposing surface 64c faces the lower side of the hooking surface 56c. The opposing surface 64c is hooked onto the hooking surface 56c from below. As a result, the claw main body portion 64b is hooked onto the housing main body 50 from below. By hooking each of the claw main bodies 64b of the multiple claws 64 onto the housing main body 50 from below, the cover member 60 is fixed to the housing main body 50 by a snap-fit ​​structure. The opposing surface 64c may be in contact with the hooking surface 56c, or may face the hooking surface 56c via a small gap. In this embodiment, the circumferential dimension of the claw main body 64b is the same as the circumferential dimension of the lower end of the arm portion 64a. As shown in FIG. 5, the radial dimension of the claw main body 64b is smaller than the radial dimension of the through hole 65. When viewed in the axial direction, the radially inner end of the claw main body 64b is located radially outward from the radially inner edge of the inner edge of the through hole 65.

[0036] The claw main bodies 64b of the multiple claws 64 are located below the multiple through holes 65. Each claw main body 64b is positioned axially opposite a corresponding through hole 65. The entire claw main body 64b overlaps with a corresponding through hole 65 when viewed axially. Therefore, when molding the lid member 60 using a mold, the claw main bodies 64b can be molded using a mold that is divided in the axial direction. Specifically, as shown by the two-dot chain line in FIG. 3 , the facing surface 64c of the claw main body 64b can be molded using the lower surface of an extension portion P that is part of the upper mold and extends in the axial direction, while the upper mold can be removed upward. This allows the claw main bodies 64b to be molded simultaneously when molding the lid member 60 using a mold. Therefore, the number of steps required to manufacture the lid member 60 can be reduced compared to when the claw main bodies 64b are formed by additionally machining a molded body formed using a mold. This reduces the manufacturing cost of the lid member 60 and, therefore, the manufacturing cost of the pump 100. Furthermore, the extension P allows the opposing surface 64c of the hook main body 64b to be suitably shaped to a desired size. This allows the hook 64 to be suitably hooked onto the housing main body 50. This makes it easy to firmly fix the cover member 60 to the housing main body 50.

[0037] When the cover member 60 is secured to the housing main body 50 by the snap-fit ​​structure, the claws 64 elastically deform radially outward. More specifically, when the cover member 60 is brought closer to the housing main body 50 from above, the claws 64 come into contact with the inclined surfaces 56a of the hooking portions 56 from above. When the cover member 60 is moved downward in this state, the claws 64 elastically deform radially outward along the inclined surfaces 56a. More specifically, the arms 64a of the claws 64 elastically deform radially outward with the upper ends of the arms 64a as fulcrums. When the cover member 60 is moved downward and the claw main bodies 64b are positioned below the hooking surfaces 56c of the hooking portions 56, the arms 64a restore their original shape radially inward, and the claw main bodies 64b move below the hooking surfaces 56c. As a result, the hook main body 64b is hooked onto the housing main body 50 from below, and the cover member 60 is fixed to the housing main body 50.

[0038] When the cover member 60 is fixed to the housing main body 50 as described above, the claw portions 64 elastically deform radially outward. If the deformation of the claw portions 64 is transmitted to the second cylindrical portion 62, the second cylindrical portion 62 may deform radially outward, which may make it difficult to seal the gap between the first cylindrical portion 51a and the second cylindrical portion 62. In contrast, in the present embodiment, an annular portion 63 protruding radially outward from the lower end of the second cylindrical portion 62 is provided between the second cylindrical portion 62 and the claw portions 64. This allows the radial position of the claw portions 64 to be radially outward of the second cylindrical portion 62, thereby preventing the deformation of the claw portions 64 from being transmitted from the claw portions 64 to the second cylindrical portion 62. Furthermore, the annular portion 63 is provided with a plurality of through holes 65. The claw main bodies 64b of the plurality of claw portions 64 are respectively located below the plurality of through holes 65. Therefore, each claw portion 64 is provided at a position in the circumferential direction where each through hole 65 is provided. As a result, each through hole 65 can prevent deformation of each claw portion 64 from being transmitted from the annular portion 63 to the second tubular portion 62. Therefore, even if the multiple claw portions 64 elastically deform when fixing the cover member 60 to the housing main body 50, deformation of the second tubular portion 62 can be prevented. As a result, deterioration in the sealing performance of the housing 30 can be prevented. As described above, according to the present embodiment, the manufacturing cost of the housing 30 can be reduced, the cover member 60 can be firmly fixed to the housing main body 50 via the multiple claw portions 64, and deterioration in the sealing performance of the housing 30 can be prevented.

[0039] As shown in FIG. 5 , in this embodiment, the circumferential dimension of each through hole 65 is larger than the circumferential dimension of each claw portion 64. Therefore, each through hole 65 more easily prevents deformation of each claw portion 64 from being transmitted to the second tubular portion 62. This more effectively prevents deterioration of the sealing performance of the housing 30. Furthermore, the extension P of the upper mold described above can be provided with a portion for molding the circumferential side surface of the claw main body portion 64b. This allows the extension P, which is part of the upper mold, to mold the opposing surface 64c and the circumferential side surface of the claw main body portion 64b. Therefore, burrs can be prevented from occurring between the opposing surface 64c of the claw main body portion 64b and the circumferential side surface, and the opposing surface 64c that hooks onto the housing main body 50 from below can be accurately molded. The circumferential dimension of the through hole 65 is the circumferential dimension of the portion of the through hole 65 where the circumferential dimension is greatest. The circumferential dimension of the claw portion 64 is the circumferential dimension of the portion of the claw portion 64 that has the largest circumferential dimension. In this embodiment, the circumferential dimension of the claw portion 64 is largest at the upper end of the arm portion 64a.

[0040] The circumferential ends of each through hole 65 are positioned farther apart in the circumferential direction than the circumferential ends of each claw portion 64. Therefore, deformation of each claw portion 64 is prevented from being transmitted to the connecting portions 66 disposed on both circumferential sides of each through hole 65. This prevents deformation of each claw portion 64 from being transmitted to the second tubular portion 62 via the connecting portions 66. This further prevents deterioration of the sealing performance of the housing 30. Furthermore, the extension portions P allow the circumferential surfaces of both sides of the claw main body portion 64b to be shaped. Therefore, burrs can be prevented from being formed between the opposing surface 64c of the claw main body portion 64b and each of the opposing surfaces in the circumferential direction, thereby enabling the opposing surface 64c to be shaped with greater precision. In this embodiment, the circumferential center of each claw portion 64 is located at the same position in the circumferential direction as the circumferential center of each through hole 65.

[0041] As described above, in this embodiment, the circumferential dimension of the connecting portion 66 is smaller than the circumferential dimension of the through hole 65. This makes it easier to make the connecting portion 66 smaller in the circumferential direction, and prevents deformation of the claw portion 64 from being transmitted to the second tubular portion 62 via the connecting portion 66. This further prevents a decrease in the sealing performance of the housing 30. Note that the circumferential dimension of the connecting portion 66 is the circumferential dimension of the portion of the connecting portion 66 that has the largest circumferential dimension.

[0042] As described above, in this embodiment, the lower surface 51f of the inner surface of the groove 51c is located above the upper surface of the annular portion 63. This makes it easy to increase the axial distance from the claw portion 64 to the groove 51c. This further prevents deformation of the claw portion 64 from being transmitted to a portion of the second tubular portion 62 that is located in the same axial position as the groove 51c. This therefore prevents deformation of the groove 51c, in which at least a portion of the seal member 70 is housed, and further prevents a decrease in the sealing performance of the housing 30.

[0043] As described above, in this embodiment, the claws 64 extend downward from the second annular wall portion 63b. Therefore, compared to when the claws 64 are directly connected to the first annular wall portion 63a, it is easier to prevent deformation transmitted from the claws 64 to the annular portion 63 from being transmitted to the second tubular portion 62. This further prevents the sealing performance of the housing 30 from being reduced.

[0044] (Variation) As shown in FIG. 6 , the pump 200 of this modified example differs from the pump 100 of the above-described embodiment in the shape of the cover member 260 of the housing 230. In the cover member 260, a sloping portion 262a is provided at the lower end of the radially inner surface of the second cylindrical portion 262, and the sloping portion 262a is positioned radially outward as it extends downward. The sloping portion 262a is annular and surrounds the central axis J. More specifically, the sloping portion 262a is annular and centered on the central axis J. By providing the sloping portion 262a, the inner diameter of the second cylindrical portion 262 at its lower end increases as it extends downward. Therefore, when the cover member 260 is fixed to the housing main body 50, the lower end of the second cylindrical portion 262 is prevented from getting caught on the seal member 70 when the first cylindrical portion 51a is inserted radially inside the second cylindrical portion 262. This prevents the position of the seal member 70 from being significantly misaligned in the axial direction. Therefore, the sealing performance of the housing 230 can be further prevented from being reduced.

[0045] The rest of the configuration of the lid member 260 is similar to the rest of the configuration of the lid member 60 of the embodiment described above. The rest of the configuration of the pump 200 is similar to the rest of the configuration of the pump 100 of the embodiment described above.

[0046] The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The number of claw portions and the number of through holes are not particularly limited as long as they are two or more. The configuration of each through hole is not particularly limited as long as the entire claw body portions overlap with each through hole when viewed in a predetermined direction. The circumferential dimension of the through hole may be the same as the circumferential dimension of the claw portion.

[0047] The groove for accommodating at least a portion of the seal member may be provided on at least one of the radially outer surface of the first cylindrical portion and the radially inner surface of the second cylindrical portion. That is, the groove may be provided on both the radially outer surface of the first cylindrical portion and the radially inner surface of the second cylindrical portion, or may be provided only on the radially inner surface of the second cylindrical portion without being provided on the radially outer surface of the first cylindrical portion. The annular portion may not have a second annular wall portion. In this case, the claw portion may extend from the radially outer edge of the first annular wall portion to the other side (lower side) in the predetermined direction. The imaginary axis surrounded by the first cylindrical portion may be an axis different from the central axis J of the pump in the above-described embodiment. The predetermined direction in which the imaginary axis extends may be any direction. For example, the predetermined direction may be perpendicular to the central axis J of the pump.

[0048] The present technology can be configured as follows. (1) A pump mechanism includes a rotatable rotor, a stator facing the rotor with a gap therebetween, a pump mechanism connected to the rotor, and a housing that accommodates the rotor, the stator, and the pump mechanism therein, the housing having a housing main body and a lid member fixed to the housing main body, the housing main body having a first cylindrical portion surrounding an imaginary axis extending in a predetermined direction, the first cylindrical portion opening on one side in the predetermined direction, the lid member having a lid portion closing the opening of the first cylindrical portion, a second cylindrical portion surrounding the first cylindrical portion, an annular portion protruding outward in a radial direction centered on the imaginary axis from an end portion on the other side in the predetermined direction of the second cylindrical portion, and a lid portion extending from an outer edge portion of the radial direction of the annular portion to the other side in the predetermined direction and having the imaginary axis as the center. a plurality of claw portions spaced apart in the circumferential direction, a seal member being provided between the first cylindrical portion and the second cylindrical portion, and each of the plurality of claw portions has an arm portion extending from the annular portion to the other side in the predetermined direction, and a claw main body portion protruding radially inward from the arm portion and hooked onto the housing main body from the other side in the predetermined direction, the annular portion being provided with a plurality of through holes that penetrate the annular portion in the predetermined direction and are spaced apart in the circumferential direction, the claw main body portions of the plurality of claw portions being respectively located on the other side of the plurality of through holes in the predetermined direction and being disposed opposite each of the through holes in the predetermined direction, and the entirety of each of the claw main bodies overlapping with each of the through holes when viewed in the predetermined direction. (2) The pump according to (1), wherein the circumferential dimension of each of the through holes is greater than the circumferential dimension of each of the claw portions. (3) The pump according to (2), wherein both ends of each of the through holes in the circumferential direction are disposed farther apart in the circumferential direction than both ends of each of the claw portions in the circumferential direction. (4) A pump described in any one of (1) to (3), wherein the annular portion has a connecting portion located between the through holes adjacent to each other in the circumferential direction of the annular portion, and the circumferential dimension of the connecting portion is smaller than the circumferential dimension of the through holes. (5) A pump described in any one of (1) to (4), wherein a groove is provided on at least one of the radial outer surface of the first cylindrical portion and the radial inner surface of the second cylindrical portion to accommodate at least a portion of the sealing member, and the inner surface of the groove located on the other side of the predetermined direction is located on one side of the predetermined direction relative to the surface on one side of the predetermined direction of the annular portion. (6) The pump according to any one of (1) to (5), wherein the first cylindrical portion is loosely fitted into the second cylindrical portion. (7) A pump described in any one of (1) to (6), wherein the annular portion has a first annular wall portion protruding radially outward from the other end of the second cylindrical portion in the predetermined direction, and a second annular wall portion protruding from the radial outer edge of the first annular wall portion to the other side in the predetermined direction, and the claw portion extends from the second annular wall portion to the other side in the predetermined direction. (8) The pump according to (7), wherein a connecting portion connecting the surface on the other side in the predetermined direction of the first annular wall portion and the radially inner surface of the second annular wall portion has a curved shape. (9) A pump according to any one of (1) to (8), wherein the inner edge of the through hole has a corner portion formed by a curve when viewed in the predetermined direction.

[0049] The configurations and methods described in this specification can be combined as appropriate within the scope of not being mutually contradictory. [Explanation of symbols]

[0050] 11...rotor, 12...stator, 20...pump mechanism, 30, 230...housing, 50...housing main body, 51a...first cylindrical portion, 51c...groove, 60, 260...lid member, 61...lid portion, 62, 262...second cylindrical portion, 63...annular portion, 63a...first annular wall portion, 63b...second annular wall portion, 63c...curved surface, 64...claw portion, 64a...arm portion, 64b...claw main body portion, 65...through hole, 65a...corner portion, 66...connecting portion, 70...sealing member, 100, 200...pump, J...central axis line (imaginary axis line)

Claims

1. a rotatable rotor; a stator facing the rotor with a gap therebetween; a pump mechanism connected to the rotor; a housing that accommodates the rotor, the stator, and the pump mechanism therein; Equipped with The housing includes: A housing body; a cover member fixed to the housing body; and the housing body has a first cylindrical portion surrounding an imaginary axis extending in a predetermined direction, the first cylindrical portion is open on one side in the predetermined direction, The cover member is a cover portion that closes the opening of the first cylindrical portion; a second cylindrical portion surrounding the first cylindrical portion; an annular portion protruding outward in a radial direction about the virtual axis line from an end portion on the other side in the predetermined direction of the second cylindrical portion; a plurality of claws extending from an outer edge portion of the annular portion in the radial direction to the other side in the predetermined direction and arranged at intervals in a circumferential direction around the imaginary axis line; and a seal member is provided between the first cylindrical portion and the second cylindrical portion; The plurality of claw portions are an arm portion extending from the annular portion to the other side in the predetermined direction; a claw main body portion that protrudes radially inward from the arm portion and is hooked onto the housing main body from the other side in the predetermined direction; and The annular portion is provided with a plurality of through holes that penetrate the annular portion in the predetermined direction and are arranged at intervals in the circumferential direction, the claw main body portions of the plurality of claw portions are respectively located on the other side of the plurality of through holes in the predetermined direction and are arranged to face each of the through holes in the predetermined direction; The entirety of each of the claw main bodies overlaps with each of the through holes when viewed in the predetermined direction.

2. The pump according to claim 1 , wherein the circumferential dimension of each of the through holes is greater than the circumferential dimension of each of the claws.

3. The pump according to claim 2 , wherein both ends of each of the through holes in the circumferential direction are disposed farther apart in the circumferential direction than both ends of each of the claw portions in the circumferential direction.

4. the annular portion has a connecting portion located between the through holes adjacent to each other in the circumferential direction of the annular portion, The pump according to claim 1 , wherein the circumferential dimension of the connecting portion is smaller than the circumferential dimension of the through hole.

5. a groove for accommodating at least a portion of the seal member is provided on at least one of the radially outer surface of the first cylindrical portion and the radially inner surface of the second cylindrical portion; The pump according to claim 1 , wherein the inner surface of the groove that is located on the other side in the predetermined direction is located on the one side in the predetermined direction of the surface of the annular portion that is on the one side in the predetermined direction.

6. The pump according to claim 1 , wherein the first cylindrical portion is clearance-fitted inside the second cylindrical portion.

7. The annular portion is a first annular wall portion protruding radially outward from an end portion of the second cylindrical portion on the other side in the predetermined direction; a second annular wall portion protruding from an outer edge portion of the first annular wall portion in the radial direction to the other side in the predetermined direction; and The pump according to claim 1 , wherein the claw portion extends from the second annular wall portion to the other side in the predetermined direction.

8. The pump according to claim 7 , wherein a connecting portion connecting the surface of the first annular wall portion on the other side in the predetermined direction and the radially inner surface of the second annular wall portion has a curved shape.

9. The pump according to claim 1 , wherein an inner edge of the through hole has a corner portion formed by a curve when viewed in the predetermined direction.

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