Pump device

Abstract

The present invention provides a pump device for increasing the flow rate of fluid flowing into the impeller to improve pump efficiency. The pump device (1) has a cover (42) having an opposing wall (50) facing the impeller (3) from one side (L1) in the axial direction, a side wall (51) surrounding the outer periphery of the impeller (3), and a suction pipe (47) extending from the radial center of the opposing wall (50) toward one side (L1) in the axial direction. The impeller (3) has: a first end plate (31) facing the opposing wall (50); a second end plate (32) facing the first end plate (31) from the other side (L2) in the axial direction and connected to a rotor (5); and a blade (33) disposed between the first end plate (31) and the second end plate (32). The first end plate (31) has a fluid suction hole (34) facing the suction pipe (47). On the inside of the cover (42), at the connection point where the opposing wall portion (50) connects to the suction pipe (47), there is a rib (57) protruding from the suction pipe (47) in the shape of fluid control.

Description

Technical Field

[0001] This invention relates to a pump device. Background Technology

[0002] Patent Document 1 describes a pump assembly that uses an electric motor to rotate an impeller disposed in a pump chamber. The pump assembly of Patent Document 1 includes a pump body with a stator molded inside a housing and a pump cover forming a pump chamber between the pump body and the housing. A rotor, rotating integrally with the impeller, is disposed at the radial center of the stator.

[0003] The pump casing is equipped with a discharge pipe and a suction pipe for the fluid. The suction pipe is located radially from the center of the wall portion opposite to the impeller on the side opposite to the outer casing, and the discharge pipe is located on the side wall portion surrounding the outer periphery of the impeller.

[0004] The impeller has blades that are curved circumferentially and extend radially outward, and a frustoconical cover that covers the blades from the opposite side of the casing. Fluid flows into the interior of the impeller through a hole located at the radial center of the cover. By rotating the impeller, the fluid is sent to the outer periphery and discharged from the discharge pipe.

[0005] The impeller housing and the pump housing are positioned opposite each other with a predetermined gap (clearance). In Patent Document 1, a protrusion protruding towards the pump housing is provided on the outer periphery of the housing, and the gap between the pump housing and the impeller is reduced at the location of the protrusion. Therefore, the backflow of fluid discharged from the outer periphery of the impeller can be suppressed, which would cause the fluid to return to the suction pipe side through the gap between the impeller and the pump housing, thus improving pump efficiency.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Chinese Patent No. 107191386 Specification Summary of the Invention

[0009] The technical problem to be solved by the invention

[0010] A portion of the fluid flowing into the pump chamber from the suction pipe of the pump shroud does not flow into the impeller but instead flows into the gap between the pump shroud and the impeller. If the flow rate of the fluid flowing into the pump chamber that flows into the impeller is increased, the pump efficiency is improved. However, in Patent Document 1, although a shape for suppressing backflow is proposed on the outer periphery of the impeller, no suggestion is made to control the water flow around the suction pipe to increase the fluid flowing into the impeller.

[0011] In view of the above problems, the objective of the present invention is to improve pump efficiency by increasing the flow rate of fluid flowing into the impeller in a pump device in which the impeller rotates inside the pump chamber.

[0012] Technical solutions adopted to solve technical problems

[0013] To solve the above problems, one aspect of the pump device of the present invention comprises: a rotor and a stator surrounding the outer periphery of the rotor; an impeller, which is opposed to the stator on one side along the axial direction of the rotor's rotation axis and rotates integrally with the rotor; and a housing forming a pump chamber in which the impeller is disposed, the housing having a cover covering the impeller from one side along the axial direction, the cover having: an opposing wall portion opposite to the impeller from one side along the axial direction; a side wall portion surrounding the outer periphery of the impeller and connected to the outer peripheral end of the opposing wall portion; and a suction pipe extending from the opposing wall portion... The rotation axis extends radially from the center to one side in the axial direction; and a discharge pipe is connected to the side wall portion. The impeller has a first end plate portion opposite to the opposing wall portion, a second end plate portion opposite to the first end plate portion from the other side of the axial direction and connected to the rotor, and a blade portion disposed between the first end plate portion and the second end plate portion. A fluid suction hole opposite to the suction pipe is provided on the first end plate portion. Inside the cover, at the connection point where the opposing wall portion connects to the suction pipe, a fluid control shape protruding from the suction pipe or the opposing wall portion is provided. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of a pump device according to an embodiment of the present invention.

[0015] Figure 2 It is a partially enlarged sectional view of the impeller and shroud.

[0016] Figure 3 It is a magnified sectional perspective view of the radial central part of the impeller and shroud.

[0017] Figure 4 This is a top view of the fluid control shape viewed from the other side of the axis.

[0018] Explanation of icon numbers

[0019] 1: Pump unit

[0020] 2: Electric motor

[0021] 3: Impeller

[0022] 4: Casing

[0023] 5: Rotor

[0024] 6: Stator

[0025] 7: Rotor components

[0026] 8: Magnet

[0027] 9: Radial bearing

[0028] 10: Support shaft

[0029] 11: Support section

[0030] 12: Cylinder section

[0031] 13: Shaft hole

[0032] 14: Thrust bearing

[0033] 30: Impeller components

[0034] 31: First end plate section

[0035] 32: Second end plate

[0036] 33: Blade section

[0037] 34: Fluid suction hole

[0038] 35: Cylinder section

[0039] 40: Pump Room

[0040] 41: Outer shell

[0041] 42: Cover

[0042] 43: First adjoining section

[0043] 44: Second partition section

[0044] 45: Bottom

[0045] 46: Main body

[0046] 47: Inhalation tube

[0047] 48: Flange portion

[0048] 49: Flange portion

[0049] 50: Opposite wall

[0050] 50a: Inner surface

[0051] 51: Side wall portion

[0052] 52: First cylindrical section

[0053] 53: Second cylindrical section

[0054] 54: concave part

[0055] 54a: Inner circumferential surface

[0056] 55: First Zone

[0057] 56: Second Zone

[0058] 57: Ribs

[0059] 61: Stator core

[0060] 62: Insulator

[0061] 63: Coil

[0062] 71: Cylindrical section

[0063] 72: Seat

[0064] C: Fluid-controlled shape

[0065] L: Axis of rotation

[0066] L1: One side along the axis

[0067] L2: The other side of the axis

[0068] R1: Front side of the rotation direction

[0069] S: Gap Detailed Implementation

[0070] The implementation of pump device 1 will now be described with reference to the accompanying drawings.

[0071] (Overall structure)

[0072] Figure 1 This is a cross-sectional view of the pump device 1 according to an embodiment of the present invention. Figure 1 As shown, the pump assembly 1 includes an electric motor 2, an impeller 3 driven by the rotation of the electric motor 2, and a housing 4 that houses the electric motor 2 and the impeller 3. The electric motor 2 includes a rotor 5 and a stator 6 surrounding the outer periphery of the rotor 5. The impeller 3 rotates integrally with the rotor 5.

[0073] In the following description, the direction along the rotation axis L of rotor 5 is defined as the axial direction, one side of the axial direction is designated as L1, and the other side of the axial direction is designated as L2. Radial refers to the radial direction centered on the rotation axis L. Circumferential refers to the circumferential direction centered on the rotation axis L.

[0074] The impeller 3 is disposed at one end L1 of the rotor 5 along its axial direction. The rotor 5 includes a rotor component 7 extending along its axial direction, a magnet 8 disposed on the outer peripheral surface of the rotor component 7, and a radial bearing 9 fixed to the radial center of the rotor component 7 by means of an embedded forming. The pump assembly 1 includes a support shaft 10 fixed to the housing 4. The rotor 5 is rotatably supported on the support shaft 10 via the radial bearing 9.

[0075] The rotor component 7 includes a cylindrical portion 71 extending along the axial direction and a seat portion 72 extending radially outward from the midpoint of the axial direction of the cylindrical portion 71. A magnet 8 is fixed to a portion of the cylindrical portion 71 on the opposite side L2 of the seat portion 72 in the axial direction. The seat portion 72 abuts against the magnet 8 from one side L1 in the axial direction to support the magnet 8.

[0076] A second end plate portion 32, which forms an impeller 3, is connected to the end of one side L1 in the axial direction of the cylindrical portion 71. An impeller component 30 is fixed to the second end plate portion 32 from one side L1 in the axial direction. The impeller component 30 has a first end plate portion 31 that faces the second end plate portion 32 from one side L1 in the axial direction and a blade portion 33 that protrudes from the first end plate portion 31 to the other side L2 in the axial direction. The impeller component 30 is fixed to the second end plate portion 32 via the blade portion 33.

[0077] The first end plate portion 31 is a frustum-shaped cone that tilts towards the radial center and towards one side L1 in the axial direction. A fluid intake hole 34 is provided through the first end plate portion 31 at its radial center, and a cylindrical portion 35 protrudes from the edge of the fluid intake hole 34 towards one side L1 in the axial direction. Multiple blade portions 33 are arranged at equal angular intervals around the fluid intake hole 34 between the first end plate portion 31 and the second end plate portion 32. Each of the multiple blade portions 33 is circumferentially curved and extends radially outward.

[0078] The stator 6 has: an annular stator core 61 surrounding the outer periphery of the rotor component 7 and the magnet 8; and a coil 63 wound around the salient pole of the stator core 61 with an insulator 62 in between. On the other side L2 in the axial direction of the stator 6, a circuit board (not shown) is disposed for supplying drive current to the coil 63.

[0079] The housing 4 includes an outer shell 41 covering the stator 6 and a cover 42 covering the outer shell 41 from one side L1 in the axial direction. The outer shell 41 is a resin sealing member into which the stator 6 is embedded. The outer shell 41 includes: a first partition wall portion 43 that covers one side L1 in the axial direction of the stator 6; a second partition wall portion 44 that is connected to the inner periphery of the first partition wall portion 43 and covers the stator 6 from the radially inner side; a bottom 45 that blocks the end of the second partition wall portion 44 from the other side L2 in the axial direction and covers the other side L2 in the axial direction of the stator 6; and a main body portion 46 that is connected to the outer periphery of the first partition wall portion 43 and covers the stator 6 from the radially outer side.

[0080] The pump chamber 40, equipped with the impeller 3, is divided by a housing 41 and a cover 42. A suction pipe 47 extending radially towards one side L1 in the axial direction is provided at the radial center of the cover 42. Additionally, a discharge pipe (not shown) extending tangentially along the outer periphery of the pump chamber 40 is provided on the cover 42. The cover 42 is fixed to the housing 41 by welding. A flange portion 48 extending radially outward is provided at the end of the other side L2 in the axial direction of the cover 42. A welding groove is formed on the flange portion 49 extending radially outward from the main body portion 46 of the housing 41; this welding groove is used to weld welding ribs provided on the flange portion 48 of the cover 42.

[0081] A cover 42 covers the impeller 3 from one side L1 in the axial direction. The cover 42 has an opposing wall portion 50 opposite to the impeller 3 from one side L1 in the axial direction, and a side wall portion 51 surrounding the outer periphery of the impeller 3 and connected to the outer periphery of the opposing wall portion 50. The opposing wall portion 50 and the side wall portion 51 and the first partition wall portion 43 of the outer casing 41 divide the pump chamber 40. The suction pipe 47 extends from the radial center of the opposing wall portion 50 to one side L1 in the axial direction, and a discharge pipe (not shown) is connected to the side wall portion 51.

[0082] The cover 42 has three support portions 11 extending from the inner circumference of the suction pipe 47 to the other side L2 in the axial direction. At the front end of each support portion 11 is a cylindrical portion 12 into which the end of the support shaft 10 on one side L1 in the axial direction is inserted. The end of the support shaft 10 on the other side L2 in the axial direction is embedded in a shaft hole 13 provided on the bottom 45 of the housing 41. A thrust bearing 14, mounted on the end of the support shaft 10 on one side L1 in the axial direction, is disposed between the end of the radial bearing 9 on one side L1 in the axial direction and the front end of the cylindrical portion 12. When the rotor 5 and impeller 3 rotate, the impeller 3 is subjected to force on one side L1 in the axial direction, and the radial bearing 9 and the thrust bearing 14 slide in contact.

[0083] (Fluid-controlled shape)

[0084] Figure 2 This is a partially enlarged sectional view of the impeller 3 and the cover 42. Figure 3 It is a partially enlarged sectional perspective view of the radial central portion of the impeller 3 and the cover 42. Figure 4 This is a top view of the fluid control shape C as seen from the opposite side L2 along the axial direction. (Example) Figure 2 , Figure 3As shown, the suction pipe 47 includes a first cylindrical portion 52 connected to the inner periphery of the opposing wall portion 50, and a second cylindrical portion 53 connected to the first cylindrical portion 52 and extending from the first cylindrical portion 52 toward one side L1 in the axial direction. The wall thickness of the first cylindrical portion 52 is greater than that of the second cylindrical portion 53, and it extends radially outward from the outer periphery of the second cylindrical portion 53. When the suction pipe 47 is connected to the fluid supply pipe (not shown), the first cylindrical portion 52 functions as a pedestal portion supporting a seal (not shown) mounted on the outer periphery of the second cylindrical portion 53 from the other side L2 in the axial direction.

[0085] like Figure 2 , Figure 3 As shown, a recess 54 is provided on the inner circumferential surface of the first cylindrical portion 52, recessed radially outward. The recess 54 is a weight-reducing portion used to suppress the thickening of the wall of the first cylindrical portion 52, and is provided on the entire circumference of the inner circumferential surface of the first cylindrical portion 52. The recess 54 extends along the axial direction to the corner where the first cylindrical portion 52 connects with the opposing wall portion 50, and opens on the inner surface of the pump chamber 40 formed by the opposing wall portion 50. As described above, a cylindrical portion 35 surrounding the fluid suction hole 34 is provided at the radial center of the impeller 3, and the front end of the cylindrical portion 35 extends inward toward the first cylindrical portion 52 and is disposed in the recess 54.

[0086] like Figure 3 As shown, when the region on the other side L2 of the recess 54 in the axial direction is designated as the first region 55, and the region on one side L1 in the axial direction relative to the first region 55 is designated as the second region 56, a rib 57 extending radially inward from the inner circumferential surface 54a of the recess 54 is provided in the second region 56. The ribs 57 are arranged circumferentially at equal angular intervals along the entire circumference of the inner side of the recess 54. The ribs 57 do not extend to the opposing wall portion 50 and are not disposed in the first region 55. The front end of the cylinder portion 35 of the impeller 3 is disposed in the first region 55, and the rib 57 is disposed on one side L1 in the axial direction of the cylinder portion 35. Therefore, the cylinder portion 35 and the rib 57 do not interfere with each other.

[0087] like Figure 3 As shown, the radially inner front end face of rib 57 is located on the same surface as the inner circumferential surface of suction pipe 47. The inner diameter of the fluid suction hole 34, which opens on the other side L2 in the axial direction of rib 57, is smaller than the inner diameter of suction pipe 47. Therefore, rib 57 is located radially outer than the inner circumferential surface of fluid suction hole 34.

[0088] Rib 57 is disposed at the connection point where the inner surface of the opposing wall portion 50 connects to the inner circumferential surface of the suction pipe 47. This portion is where the suction pipe 47 connects to the pump chamber 40, and the rib 57 disposed at this portion functions as a fluid control shape C to control the flow of fluid into the pump chamber 40 and the impeller 3. By providing rib 57 at this portion, turbulence is generated as the impeller 3 rotates. As a result, the flow of fluid toward the gap S between the opposing wall portion 50 and the first end plate portion 31 of the impeller 3 is impeded, and the flow rate into the impeller 3 increases. This improves pump efficiency.

[0089] like Figure 2 , Figure 3 As shown, rib 57 tilts towards the circumferential side as it moves towards the radially inward side. (As...) Figure 3 As shown, in this configuration, the rib 57 is inclined towards the front side R1 in the direction of rotation of the impeller 3, while also being radially inward. With the rib 57 inclined in this direction, the fluid colliding with the rib 57 as the impeller 3 rotates is more likely to generate turbulence. Therefore, pump efficiency is improved.

[0090] In this method, to avoid increasing the wall thickness at the radially outward extension of the first cylindrical portion 52 of the suction pipe 47, a recess 54 is provided on the inner circumferential surface of the first cylindrical portion 52. At the location where the recess 54 is provided, the gap between the cover 42 and the impeller 3 increases, making it easier for fluid to flow into the gap S between the opposing wall portion 50 and the impeller 3, potentially reducing pump efficiency. Therefore, a structure is adopted where the recess 54 is configured with ribs 57 that function as a fluid control shape C, generating turbulence and thereby improving pump efficiency.

[0091] The inventors performed fluid analysis using a three-dimensional model of the pump assembly 1 according to this method and a three-dimensional model of the pump assembly without the rib 57, determining the pressure distribution within the pump chamber 40 and the thrust exerted on one side L1 of the impeller 3 in the axial direction when the impeller 3 rotates. An increase in thrust implies an increase in pump efficiency. The thrust with the rib 57 is 25.02 N, compared to 10.88 N without the rib 57. Therefore, it can be confirmed that with the rib 57, the increased thrust leads to improved pump efficiency.

[0092] (Effects)

[0093] As described above, the pump device 1 of this embodiment includes: a rotor 5 and a stator 6 surrounding the outer periphery of the rotor 5; an impeller 3, which is disposed relative to the stator 6 along one axial side L1 of the rotation axis L of the rotor 5 and rotates integrally with the rotor 5; and a housing 4, which forms a pump chamber 40 in which the impeller 3 is disposed. The housing 4 includes a cover 42 covering the impeller 3 from one axial side L1. The cover 42 includes: an opposing wall portion 50, which faces the impeller 3 from one axial side L1; a side wall portion 51, which surrounds the outer periphery of the impeller 3 and is connected to the outer peripheral end of the opposing wall portion 50; a suction pipe 47, which extends from the radial center of the opposing wall portion 50 centered on the rotation axis L towards one axial side L1; and a discharge pipe, which is connected to the side wall portion 51 (not shown). The impeller 3 includes a first end plate portion 31 opposite to the opposing wall portion 50, a second end plate portion 32 opposite to the first end plate portion 31 from the other side L2 in the axial direction and connected to the rotor 5, and a blade portion 33 disposed between the first end plate portion 31 and the second end plate portion 32. The first end plate portion 31 is provided with a fluid suction hole 34 opposite to the suction pipe 47. Inside the cover 42, at the connection point where the opposing wall portion 50 connects to the suction pipe 47, a rib 57 protruding from the suction pipe 47 and forming a fluid control shape C is provided.

[0094] In this method, by providing ribs 57 at the aforementioned locations, turbulence is generated as the impeller 3 rotates. This obstructs the flow of fluid from the suction pipe 47 toward the gap S between the opposing wall portion 50 and the first end plate portion 31, and increases the flow rate into the impeller 3 from the fluid suction hole 34. Therefore, pump efficiency can be improved.

[0095] Furthermore, when a fluid control shape C is provided at the connection point where the opposing wall portion 50 connects to the suction pipe 47, its shape is not limited to a shape protruding from the suction pipe 47. For example, a shape protruding from the inner side surface 50a of the opposing wall portion 50 toward the first end plate portion 31 may also be provided at the connection point where the opposing wall portion 50 connects to the suction pipe 47. That is, as long as a fluid control shape C protruding from either the opposing wall portion 50 or the suction pipe 47 is provided at the connection point where the opposing wall portion 50 connects to the suction pipe 47, it is acceptable. The fluid control shape C is not limited to a rib.

[0096] In this configuration, the rib 57, which forms the fluid control shape C, is located radially outward from the inner circumferential surface of the fluid intake hole 34. This prevents the inflow of fluid into the impeller 3 from being obstructed by the rib 57.

[0097] In this configuration, within the housing 42, a plurality of radially extending ribs 57 are arranged circumferentially at the connection point where the opposing wall portion 50 connects to the suction pipe 47. When radially extending ribs 57 are provided, turbulence is generated around the ribs 57 as the impeller 3 rotates. Therefore, pump efficiency can be improved.

[0098] Furthermore, in this embodiment, a fluid control shape C is disposed within a recess 54 on the inner circumferential surface of the suction pipe 47. However, the recess 54 may be omitted, and instead, a fluid control shape C protruding radially inward from the inner circumferential surface of the suction pipe 47 may be provided. Additionally, if the fluid control shape C is provided on the opposing wall portion 50, ribs protruding from the opposing wall portion 50 toward the other side L2 in the axial direction may be provided radially around the suction pipe 47.

[0099] In this design, rib 57 is inclined towards the front side R1 in the direction of rotation of impeller 3, moving radially outward. This shape facilitates turbulence around rib 57 as impeller 3 rotates, thus further improving pump efficiency.

[0100] In this configuration, the cover 42 has a recess 54 at the connection point where the opposing wall portion 50 connects to the suction pipe 47, recessed radially outward from the inner circumference of the suction pipe 47, and a rib 57 is disposed within the recess 54. This allows the rib 57 to be positioned further outward than the inner diameter of the suction pipe 47, making it easier to position the rib 57 radially outward than the fluid suction port 34.

[0101] In this configuration, the impeller 3 has a cylindrical portion 35 protruding from the edge of the fluid suction port 34 toward one side L1 in the axial direction. The front end of the cylindrical portion 35 is inserted into a recess 54, and a rib 57 is provided on the side L1 in the axial direction relative to the cylindrical portion 35. As a result, since the fluid suction port 34 is opened inside the suction pipe 47, fluid can easily flow into the impeller 3.

[0102] In this configuration, the suction pipe 47 includes a first cylindrical portion 52 connected to the inner periphery of the opposing wall portion 50, and a second cylindrical portion 53 extending from the first cylindrical portion 52 toward one side L1 in the axial direction. The first cylindrical portion 52 extends further outward in the radial direction than the second cylindrical portion 53, and a recess 54 is provided inside the first cylindrical portion 52. The first cylindrical portion 52 functions as a pedestal portion supporting a seal embedded in the outer periphery of the second cylindrical portion 53 from the other side L2 in the axial direction. This prevents the portion of the suction pipe 47 with the radially outward-extending pedestal portion from becoming thickened, thus suppressing molding defects during the manufacture of the cover 42 and improving dimensional stability. Furthermore, the fluid control shape C can be formed using the recess 54, which serves as a weight-reducing portion.

[0103] In this configuration, the ribs 57 are arranged at equal angular intervals along the entire circumference of the inner circumference of the suction pipe 47. This allows turbulence to be generated along the entire circumference.

[0104] (Summary)

[0105] The present invention can be implemented in the following ways.

[0106] (1)

[0107] A pump device, comprising:

[0108] The rotor and the stator surrounding the outer periphery of the rotor;

[0109] An impeller, which is positioned opposite the stator on one side along the axial direction of the rotor's rotation axis and rotates integrally with the rotor; and

[0110] The housing forms the pump chamber in which the impeller is configured.

[0111] The housing has a cover that covers the impeller from one side along the axial direction.

[0112] The shroud includes: an opposing wall portion opposite to the impeller from one side in the axial direction; a side wall portion surrounding the outer periphery of the impeller and connected to the outer peripheral end of the opposing wall portion; a suction pipe extending from the radial center of the opposing wall portion about the axis of rotation towards one side in the axial direction; and a discharge pipe connected to the side wall portion.

[0113] The impeller includes a first end plate portion opposite to the opposing wall portion, a second end plate portion opposite to the first end plate portion from the other side of the axial direction and connected to the rotor, and a blade portion disposed between the first end plate portion and the second end plate portion. A fluid suction hole opposite to the suction pipe is provided on the first end plate portion.

[0114] Inside the cover, at the connection point where the opposing wall portion connects to the suction tube, a fluid control shape protruding from the suction tube or the opposing wall portion is provided.

[0115] (2)

[0116] According to the pump device described in (1) above,

[0117] The fluid control shape is located radially outward from the inner circumferential surface of the fluid intake orifice.

[0118] (3)

[0119] According to the pump device described in (1) above,

[0120] In the shroud, at the connection point where the opposing wall meets the suction tube, a plurality of ribs extending radially inward are arranged in a circumferential manner.

[0121] The fluid control shape is the rib.

[0122] (4)

[0123] According to the pump device described in (3) above,

[0124] The ribs tilt toward the front side of the impeller's rotation direction as they move toward the radially outward side.

[0125] (5)

[0126] According to the pump device described in (3) above, a recess is provided in the cover at the connection point where the opposing wall and the suction pipe connect, with the recess extending radially outward from the inner circumference of the suction pipe.

[0127] The rib is disposed within the recess.

[0128] (6)

[0129] According to the pump device described in (5) above,

[0130] The impeller has a cylindrical portion that protrudes from the edge of the fluid intake hole toward one side in the axial direction.

[0131] The front end of the cylindrical portion is positioned within the recess.

[0132] The rib is disposed on one side of the cylindrical portion in the axial direction.

[0133] (7)

[0134] According to the pump device described in (5) above,

[0135] The inhalation tube includes a first cylindrical portion connected to the inner periphery of the opposing wall portion, and a second cylindrical portion extending from the first cylindrical portion to one side in the axial direction.

[0136] The first cylindrical portion extends further outward in the radial direction than the second cylindrical portion, and the recess is located on the inner side of the first cylindrical portion.

[0137] The first cylindrical portion functions as a pedestal portion that supports the seal embedded in the outer peripheral side of the second cylindrical portion from the other side of the axial direction.

[0138] (8)

[0139] According to any one of (1) to (7) above, the pump device,

[0140] The ribs are arranged at equal angular intervals around the entire circumference of the inhalation tube.

Claims

1. A pump device, characterized in that, have: The rotor and the stator surrounding the outer periphery of the rotor; An impeller, which is positioned opposite the stator on one side along the axial direction of the rotor's rotation axis and rotates integrally with the rotor; and The housing forms the pump chamber in which the impeller is configured. The housing has a cover that covers the impeller from one side along the axial direction. The shroud includes: an opposing wall portion that faces the impeller from one side in the axial direction; a side wall portion that surrounds the outer periphery of the impeller and is connected to the outer periphery end of the opposing wall portion; and a suction pipe that extends from the radial center of the opposing wall portion about the axis of rotation to one side in the axial direction. And a discharge pipe, which is connected to the side wall portion, The impeller includes a first end plate portion opposite to the opposing wall portion, a second end plate portion opposite to the first end plate portion from the other side of the axial direction and connected to the rotor, and a blade portion disposed between the first end plate portion and the second end plate portion. A fluid suction hole opposite to the suction pipe is provided on the first end plate portion. Inside the cover, at the connection point where the opposing wall connects to the suction tube, a fluid control shape protruding from the suction tube or the opposing wall is provided.

2. The pump device according to claim 1, characterized in that, The fluid control shape is located radially outward from the inner circumferential surface of the fluid intake orifice.

3. The pump device according to claim 1, characterized in that, In the cover, at the connection between the opposing wall and the suction tube, a plurality of ribs extending radially inward are arranged in a circumferential manner. The fluid control shape is the rib.

4. The pump device according to claim 3, characterized in that, The ribs tilt toward the front side of the impeller's rotation direction as they move toward the radially outward side.

5. The pump device according to claim 3, characterized in that, The cover has a recessed portion that extends radially outward from the inner circumference of the suction tube at the connection point between the opposing wall and the suction tube. The rib is disposed within the recess.

6. The pump device according to claim 5, characterized in that, The impeller has a cylindrical portion that protrudes from the edge of the fluid suction port toward one side in the axial direction, and the front end of the cylindrical portion is disposed in the recess. The rib is disposed on one side of the cylindrical portion in the axial direction.

7. The pump device according to claim 5, characterized in that, The inhalation tube includes a first cylindrical portion connected to the inner periphery of the opposing wall portion and a second cylindrical portion extending from the first cylindrical portion to one side in the axial direction. The first cylindrical portion extends radially outward compared to the second cylindrical portion, and the recess is located on the inner side of the first cylindrical portion. The first cylindrical portion functions as a pedestal portion that supports the seal embedded in the outer peripheral side of the second cylindrical portion from the other side of the axial direction.

8. The pump device according to claim 3, characterized in that, The ribs are arranged at equal angular intervals around the entire circumference of the inhalation tube.

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