CN115681199A - Pump device - Google Patents

Abstract

A pump device is provided to help ensure a seal ring sandwiched between a first housing and a second housing constituting a pump chamber to perform a sealing function. The pump device of the present invention includes a casing and an impeller, the casing having a first casing and a second casing which constitute a pump chamber in which the impeller is rotatably housed, the first casing having a cylindrical first portion surrounding the impeller from an outer peripheral side and a cylindrical second portion located on one axial side of the first portion, an annular surface facing one axial side being formed between the first portion and the second portion, the second casing having a cylindrical facing portion facing the second portion on an inner peripheral side, a seal ring surrounding a rotation axis of the impeller being interposed between an inner peripheral surface of the second portion and an outer peripheral surface of the facing portion, the annular surface having a narrow width portion with a smallest radial dimension, a retaining member being engaged between the inner peripheral surface of the second portion and the outer peripheral surface of the facing portion, the retaining member being located between the seal ring and the annular surface in the axial direction and corresponding to at least the narrow width portion in the circumferential direction.

Description

Pump device

Technical Field

The present invention relates to a pump device.

Background

Conventionally, there is a pump device including a housing having a first housing and a second housing that constitute a pump chamber in which the impeller is rotatably housed, the first housing having a cylindrical first portion surrounding the impeller from an outer peripheral side and a cylindrical second portion located on one side in an axial direction of the first portion, an annular surface facing one side in the axial direction being formed between the first portion and the second portion, and an impeller having a cylindrical facing portion facing the second portion on an inner peripheral side, and a seal ring surrounding a rotation axis of the impeller being sandwiched between an inner peripheral surface of the second portion and an outer peripheral surface of the facing portion (that is, an inner peripheral surface of the second portion and an outer peripheral surface of the facing portion are respectively in contact with the seal ring).

In the above-described pump device, in order to avoid an increase in size, it is sometimes not possible to ensure that the annular surface has a large radial dimension over the entire length, and the radial dimension of the annular surface is small at some circumferential portions, so that there is a possibility that a portion of the seal ring corresponding to the portion of the annular surface having a small radial dimension in the circumferential direction will pass over the annular surface and enter the pump chamber, and the seal ring cannot effectively function to seal the gap between the first casing and the second casing to prevent fluid leakage in the pump chamber.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a pump device that helps ensure that a seal ring interposed between a first housing and a second housing that constitute a pump chamber performs a sealing function.

In order to achieve the above object, the present invention provides a pump apparatus including a housing having a first housing and a second housing constituting a pump chamber in which the impeller is rotatably housed, the first housing having a cylindrical first portion surrounding the impeller from an outer peripheral side and a cylindrical second portion located on one side in an axial direction of the first portion, an annular surface facing one side in the axial direction being formed between the first portion and the second portion, the second housing having a cylindrical facing portion facing the second portion on an inner peripheral side, a seal ring surrounding a rotation axis of the impeller being sandwiched between an inner peripheral surface of the second portion and an outer peripheral surface of the facing portion, wherein the annular surface has a narrow width portion having a smallest radial dimension, a retainer is retained between the inner peripheral surface of the second portion and the outer peripheral surface of the facing portion, the retainer being located between the seal ring and the annular surface in the axial direction and corresponding to at least the narrow width portion in the circumferential direction.

Here, the annular surface is not limited to a case where the annular surface is continuous over the entire circumference to form a closed ring.

According to the pump device of the present invention, the annular surface has the narrow width portion having the smallest radial dimension, the retainer is locked between the inner peripheral surface of the second portion and the outer peripheral surface of the opposing portion, and the retainer is positioned between the seal ring and the annular surface in the axial direction and at least circumferentially corresponds to the narrow width portion, so that it is possible to prevent a part of the seal ring from entering the pump chamber beyond the narrow width portion by the retainer, and it is possible to contribute to ensuring that the seal ring performs a function of sealing the gap between the first casing and the second casing to prevent the fluid leakage in the pump chamber.

In the pump device according to the present invention, it is preferable that the inner peripheral surface of the first portion has an involute shape when viewed in the axial direction.

According to the pump device of the present invention, the inner peripheral surface of the first portion has an involute shape when viewed in the axial direction, and therefore, the pump device contributes to noise reduction during operation of the pump device.

In the pump apparatus of the present invention, it is preferable that the holder is formed in an annular shape integrally surrounding a rotation axis of the impeller.

According to the pump apparatus of the present invention, since the holder is formed in an annular shape entirely around the rotation axis of the impeller, the seal ring is prevented from entering the pump chamber over the annular surface by the holder over the entire circumference, and the seal ring can be reliably ensured to play a role of sealing the gap between the first casing and the second casing to prevent the fluid in the pump chamber from leaking.

Further, in the pump apparatus of the present invention, it is preferable that the holder is a split ring having an opening at one position in the circumferential direction.

According to the pump device of the present invention, since the retainer is an open ring having an opening at one position in the circumferential direction, the retainer is easily elastically deformed in the radial direction to fit on the outer circumferential side of the opposing portion, and the assembly efficiency is improved.

In the pump device of the present invention, it is preferable that the holder is in contact with an outer peripheral surface of the opposing portion or an inner peripheral surface of the second portion in a circumferential direction by an elastic restoring force.

According to the pump device of the present invention, the retainer is brought into contact with the outer peripheral surface of the opposing portion or the inner peripheral surface of the second portion in the circumferential direction by the elastic restoring force, and therefore, the displacement of the retainer with respect to the predetermined position is suppressed, and the generation of noise due to the displacement of the retainer is prevented.

In the pump apparatus of the present invention, it is preferable that the opening is located at a portion of the annular surface having a largest radial dimension.

According to the pump device of the present invention, the opening is located at the portion of the annular surface where the radial dimension is largest, and therefore, it is easy to suppress the influence of the protrusion of the holder toward the pump chamber at both ends facing each other across the opening on the operation of the pump device.

Further, in the pump apparatus of the present invention, it is preferable that the radial dimension of the annular surface is gradually reduced toward one side in the circumferential direction.

In the pump device according to the present invention, it is preferable that the inner peripheral surface of the second portion and the outer peripheral surface of the opposite portion each have a circular shape whose center coincides with the center of the involute curve when viewed in the axial direction.

According to the pump device of the present invention, the inner peripheral surface of the second portion and the outer peripheral surface of the opposing portion each have a circular shape whose center coincides with the center of the involute curve when viewed in the axial direction, and therefore, the pump device contributes to downsizing in the radial direction.

In the pump device of the present invention, it is preferable that the rigidity of the retainer is higher than the rigidity of the seal ring.

According to the pump device of the present invention, since the rigidity of the retainer is higher than the rigidity of the seal ring, even if the retainer moves from one side in the axial direction to the other side in the axial direction and comes into contact with the annular surface, the retainer does not easily go over the annular surface, whereby the seal ring can be reliably suppressed from entering the pump chamber beyond the annular surface by the retainer, and the seal ring can be ensured to play a role of sealing the gap between the first casing and the second casing to prevent the fluid in the pump chamber from leaking

In the pump apparatus according to the present invention, it is preferable that the second casing has an annular portion that extends from the facing portion toward an outer peripheral side and that is axially abutted against an end surface of the second portion to perform axial positioning of the first casing with respect to the second casing, a stepped portion is provided at a boundary between the annular portion and the facing portion, the seal ring is axially positioned between the stepped portion and the holder, and the stepped portion is radially abutted against an inner peripheral surface of the second portion to perform radial positioning of the first casing with respect to the second casing.

According to the pump apparatus of the present invention, the second casing has the annular portion which expands from the facing portion toward the outer peripheral side and which abuts against the end surface of the second portion in the axial direction to perform axial positioning of the first casing with respect to the second casing, the stepped portion is provided at the boundary between the annular portion and the facing portion, the seal ring is positioned between the stepped portion and the holder in the axial direction, and the stepped portion abuts against the inner peripheral surface of the second portion in the radial direction to perform radial positioning of the first casing with respect to the second casing, and therefore, axial positioning and radial positioning can be simultaneously performed at the same position, which contributes to simplification of the positioning structure.

(effect of the invention)

According to the present invention, since the annular surface has the narrow portion with the smallest radial dimension, and the retainer is interposed between the inner peripheral surface of the second portion and the outer peripheral surface of the opposing portion, and the retainer is positioned between the seal ring and the annular surface in the axial direction and at least corresponds to the narrow portion in the circumferential direction, it is possible to prevent a part of the seal ring from entering the pump chamber beyond the narrow portion by the retainer, and it is possible to contribute to ensuring that the seal ring performs the function of sealing the gap between the first casing and the second casing to prevent the fluid in the pump chamber from leaking.

Drawings

Fig. 1 is a perspective view schematically showing a pump device according to an embodiment of the present invention.

Fig. 2 is a perspective view schematically showing a first housing included in a pump device according to an embodiment of the present invention, and shows a state in which a holder is attached.

Fig. 3 is a bottom view schematically showing a first housing included in the pump device according to the embodiment of the present invention, and shows a state where the holder is attached.

Fig. 4 is a bottom view schematically showing a first casing included in the pump device according to the embodiment of the present invention, and shows a state where the holder is removed.

Fig. 5 is a perspective view schematically showing a second casing, a third casing, and a fourth casing included in the pump device according to the embodiment of the present invention, and shows a state where a holder is provided.

Fig. 6A is a partial cross-sectional view schematically showing a pump device according to an embodiment of the present invention, taken along a direction in which a rotation axis of an impeller extends.

Fig. 6B is a partial cross-sectional view schematically showing the pump device according to the embodiment of the present invention, taken along the direction in which the rotation axis of the impeller extends, and shows a portion 180 degrees apart from the portion shown in fig. 6A in the circumferential direction.

(symbol description)

1. Pump device

10. Outer casing

11. First shell

111. Cylindrical part

111A first part

111B second part

1111. Discharge pipe

112. Top part

1121. Suction tube

1122. Shaft support

12. Second housing

121. Barrel part

122. Flange part

1221. A first annular part

1222. A second annular part

1223. Opposite part

1224. Step part

13. Third shell

14. Fourth outer case

20. Impeller

21. Base part

22. Cover part

23. Blade

30. Stator

70. Screw nail

80. Sealing ring

90. Holding member

P1 outlet pipe part

P2 connecting pipe part

CB pump chamber

SF Ring face

SF1 narrow part

OP opening

Detailed Description

Next, a pump device according to an embodiment of the present invention will be described with reference to fig. 1 to 6B, in which fig. 1 is a perspective view schematically showing the pump device according to the embodiment of the present invention, fig. 2 is a perspective view schematically showing a first casing included in the pump device according to the embodiment of the present invention and showing a state in which a holder is attached, fig. 3 is a bottom view schematically showing the first casing included in the pump device according to the embodiment of the present invention and showing a state in which the holder is attached, fig. 4 is a bottom view schematically showing the first casing included in the pump device according to the embodiment of the present invention and showing a state in which the holder is detached, fig. 5 is a perspective view schematically showing a second casing, a third casing, and a fourth casing included in the pump device according to the embodiment of the present invention and showing a state in which the holder is provided, fig. 6A is a partial cross-sectional view schematically showing the pump device according to the embodiment of the present invention cut along an extending direction of a rotation axis of an impeller, and fig. 6B is a partial cross-sectional view schematically showing a portion of the pump device according to the embodiment of the present invention and a portion thereof cut away from a circumferential direction of the impeller, and a portion thereof, which is 180 degrees.

Here, for convenience of explanation, three directions orthogonal to each other are set as an X direction, a Y direction, and a Z direction, and one side of the X direction is set as X1, the other side of the X direction is set as X2, one side of the Y direction is set as Y1, the other side of the Y direction is set as Y2, one side of the Z direction is set as Z1, the other side of the Z direction is set as Z2, and an extending direction of a rotation axis of the impeller is set to coincide with the Z direction.

Further, in the present disclosure, the axial direction, the circumferential direction, the radial direction, the outer circumferential side, and the inner circumferential side are defined with reference to the rotation axis of the impeller.

(integral construction of Pump device)

As shown in fig. 1, 6A, and 6B, the pump device 1 includes a casing 10 and an impeller 20, and the casing 10 has a pump chamber CB in which the impeller 20 is rotatably housed.

Here, as shown in fig. 1, the casing 10 is formed with a discharge pipe 1111 and a suction pipe 1121, the discharge pipe 1111 extends from the pump chamber CB toward the outer circumferential side, and the suction pipe 1121 extends from the pump chamber CB along the rotation axis of the impeller 20.

As shown in fig. 6A and 6B, the stator 30 is further provided in the housing 10, and the rotor and the circuit board are further provided in the housing 10, although not shown. The stator 30 is fixed to the housing 10, the rotor is surrounded by the stator 30 from the outer peripheral side, is rotatable about the rotation axis of the impeller 20 with respect to the stator 30, and is connected to the impeller 20, and the circuit board is electrically connected to the stator 30.

In the pump device 1, when the stator 30 is supplied with power to rotate the rotor, the rotor rotates the impeller 20, and the fluid is sucked into the pump chamber CB from the suction pipe 1121, pressurized, and discharged to the outside from the discharge pipe 1111.

(Structure of housing)

As shown in fig. 1, 6A, and 6B, the casing 10 includes a first casing 11 and a second casing 12, and the first casing 11 and the second casing 12 together constitute a pump chamber CB in which the impeller 20 is housed.

Here, as shown in fig. 1, a third housing 13 is provided on the side of the second housing 12 opposite to the first housing 11, a fourth housing 14 is provided on the side of the third housing 13 opposite to the second housing 12, and a stator and a circuit board are embedded in the third housing 13. The first casing 11, the second casing 12, the third casing 13, and the fourth casing 14 are arranged in order in an axial direction (in the illustrated example, the Z direction) which is an extending direction of the rotation axis of the impeller 20, and are fixed together by screws 70.

Further, as shown in fig. 1, 2, 6A, and 6B, the first housing 11 is formed, for example, by resin molding, and has a cylindrical portion 111 and a top portion 112, the cylindrical portion 111 extending in the axial direction, and the top portion 112 provided on the other side (Z1 direction side in the illustrated example) of the cylindrical portion 111 in the axial direction. The cylindrical portion 111 has a cylindrical first portion 111A surrounding the impeller 20 from the outer peripheral side and a cylindrical second portion 111B located on one side (Z2 direction side in the illustrated example) in the axial direction of the first portion 111A, and an annular surface SF facing one side in the axial direction is formed between the first portion 111A and the second portion 111B (in the illustrated example, the annular surface SF is perpendicular to the axial direction, but is not limited thereto, and may be inclined with respect to the axial direction). As shown in fig. 3 and 4, the annular surface SF has a narrow portion SF1 having the smallest radial dimension (in the illustrated example, an end portion of the annular surface SF in the clockwise direction in the circumferential direction). Specifically, as shown in fig. 3 and 4, the radial dimension of the annular surface SF is gradually reduced toward one side in the circumferential direction, and more specifically, the inner peripheral surface of the first portion 111A has an involute shape (in the illustrated example, an involute shape having a center coinciding with the rotation axis of the impeller 20) when viewed in the axial direction, and the inner peripheral surface of the second portion 111B has a circular shape having a center coinciding with the center of the involute shape. As shown in fig. 3 and 4, the cylindrical portion 111 is provided with a discharge pipe 1111, the discharge pipe 1111 protrudes from the cylindrical portion 111 toward the outer peripheral side in the direction perpendicular to the axial direction, the discharge pipe 1111 includes an outlet pipe portion P1 and a connection pipe portion P2 having a smaller flow cross-sectional area than the outlet pipe portion P1, and the connection pipe portion P2 extends from the end of the involute (the largest distance from the outer peripheral surface of the impeller 20) toward the outer peripheral side along the tangent line at the end to the outlet pipe portion P1. Further, the ceiling portion 112 is formed with a suction pipe 1121, and the suction pipe 1121 extends in the axial direction from the center of the ceiling portion 112 (extends toward the Z1 direction side in the illustrated example). The top portion 112 also has a shaft support portion 1122 formed thereon, and the shaft support portion 1122 supports the rotor rotatably about the rotation axis of the impeller 20 via a shaft portion (not shown).

As shown in fig. 1, 6A, and 6B, the second housing 12 is formed by, for example, resin molding, and has a cylinder portion 121, a flange portion 122, and a bottom portion (not shown), the cylinder portion 121 extending in the axial direction around the rotation axis of the impeller 20 and surrounding the rotor from the outer peripheral side, the flange portion 122 extending from the other side (Z1 direction side in the illustrated example) of the cylinder portion 121 in the axial direction toward the outer peripheral side, and the bottom portion being provided on one side (Z2 direction side in the illustrated example) of the cylinder portion 121 in the axial direction, and having a shaft support portion that supports the rotor by the shaft portion so as to be rotatable around the rotation axis of the impeller 20. The flange portion 122 includes a first annular portion 1221, a second annular portion 1222, and an opposing portion 1223, the first annular portion 1221 is plate-shaped with a thickness direction substantially matching the axial direction, an inner peripheral edge thereof is connected to the other side in the axial direction of the cylindrical portion 121, the second annular portion 1222 is also plate-shaped with a thickness direction substantially matching the axial direction, the second annular portion 1222 is positioned on the outer peripheral side of the first annular portion 1221 and positioned on one side in the axial direction of the first annular portion 1221, the opposing portion 1223 is cylindrical extending in the axial direction, an outer peripheral surface of the opposing portion 1223 is circular with a center matching the center of the involute as viewed in the axial direction, and the opposing portion 1223 is opposed to the second portion 111B of the first housing 11 on the inner peripheral side thereof, and connects the outer peripheral portion of the first annular portion 1221 to the inner peripheral portion of the second annular portion 1222. The second annular portion 1222 extends from the facing portion 1223 toward the outer peripheral side, and abuts against an end surface (i.e., an axial end surface) of the second portion 111B of the first housing 11 in the axial direction (in the example shown in the drawing, from the Z2 direction side) to perform axial positioning of the first housing 11 with respect to the second housing 12, a step portion 1224 is provided at a boundary between the second annular portion 1222 and the facing portion 1223, and the step portion 1224 abuts against an inner peripheral surface of the second portion 111B of the first housing 11 in the radial direction to perform radial positioning of the first housing 11 with respect to the second housing 12 (in the example shown in the drawing, a chamfer is formed at an end portion on the Z2 direction side of the inner peripheral surface of the second portion 111B, but the chamfer is not limited thereto, and may not be formed).

Further, as shown in fig. 6A and 6B, the third housing 13 covers the stator 30 and the circuit board, and is formed of, for example, a bulk molding compound.

Further, as shown in fig. 1 and 5, the fourth housing 14 constitutes a base.

(construction of impeller)

As shown in fig. 6A and 6B, the impeller 20 includes a base portion 21, a cover portion 22, and blades 23.

As shown in fig. 6A and 6B, the base portion 21 has a plate shape whose thickness direction substantially coincides with the axial direction, and a through hole through which the shaft support portion 1122 passes is formed in the center of the base portion 21.

As shown in fig. 6A and 6B, the cover portion 22 is plate-shaped with its thickness direction substantially aligned with the axial direction, is positioned on the other side (Z1 direction side in the illustrated example) in the axial direction of the base portion 21, and has a through hole formed in the center of the cover portion 22 through which the shaft support portion 1122 passes.

Further, as shown in fig. 6A and 6B, the vane 23 is located between the base portion 21 and the lid portion 22 in the axial direction. A plurality of blades 23 are provided at intervals around the rotation axis of impeller 20, and blades 23 extend in an arc shape from the inner circumferential side to the outer circumferential side to the vicinity of the outer circumferential edges of base portion 21 and lid portion 22.

(sealing Structure between first case and second case)

As shown in fig. 2, 3, 6A, and 6B, the seal ring 80 surrounding the rotation axis of the impeller 20 is sandwiched between the outer peripheral surface of the facing portion 1223 of the second casing 12 and the inner peripheral surface of the second portion 111B of the first casing 11 (i.e., the outer peripheral surface of the facing portion 1223 of the second casing 12 and the inner peripheral surface of the second portion 111B of the first casing 11 are in contact with the seal ring 80 from both sides in the radial direction), the retainer 90 is locked between the inner peripheral surface of the second portion 111B of the first casing 11 and the outer peripheral surface of the facing portion 1223 of the second casing 12, and the retainer 90 is positioned between the seal ring 80 and the annular surface SF in the axial direction and corresponds to at least the narrow width portion SF1 in the circumferential direction.

Here, as shown in fig. 6A and 6B, the seal ring 80 is located between the step 1224 and the retainer 90 in the axial direction. Specifically, the seal ring 80 abuts the step portion 1224 in the axial direction (from the Z1 direction side in the illustrated example). The seal ring 80 is axially separated from the holder 90. The seal ring 80 is made of rubber, for example.

As shown in fig. 2, 3, and 5, the holder 90 is formed in a ring shape that entirely surrounds the rotation axis of the impeller 20. Specifically, the holder 90 is an open ring having an opening OP at one position in the circumferential direction, the opening OP is located at a portion of the annular surface SF where the radial dimension is largest (in the illustrated example, in the vicinity of the start end of the involute), and the holder 90 abuts against the outer peripheral surface of the opposing portion 1223 of the second housing 12 in the circumferential direction by an elastic restoring force (in the illustrated example, the opposing portion 1223 is held tightly over the entire length direction of the holder 90). Also, the rigidity of the retainer 90 is greater than that of the seal ring 80. As shown in fig. 6A and 6B, the holder 90 abuts against the annular surface SF over substantially the entire length thereof in the axial direction (from the Z2 direction side in the illustrated example). As shown in fig. 6A and 6B, chamfers are formed on both ends of the outer circumferential surface of the holder 90 in the axial direction. Also, the holder 90 is made of, for example, metal or resin.

(main effect of the present embodiment)

According to the pump device 1 of the present embodiment, the annular surface SF located between the cylindrical first section 111A and the cylindrical second section 111B of the first housing 11 has the narrow width portion SF1 having the smallest radial dimension, the retainer 90 is locked between the inner peripheral surface of the second section 111B of the first housing 11 and the outer peripheral surface of the facing portion 1223 of the second housing 12, and the retainer 90 is located between the seal ring 80 and the annular surface SF in the axial direction and at least corresponds to the narrow width portion SF1 of the annular surface SF1 in the circumferential direction, so even if the annular surface SF cannot have the narrow width portion SF1 in a part of the circumferential direction due to injection molding or the like, the retainer 90 prevents a part of the seal ring 80 from entering the pump chamber beyond the narrow width portion SF1, and contributes to ensuring that the seal ring 80 seals a gap between the first housing 11 and the second housing 12 to prevent fluid leakage in the pump chamber.

The invention is described above with reference to the accompanying drawings as an example, it is obvious that the invention is not limited to the above embodiments.

For example, in the above embodiment, the holder 90 is an open ring having the opening OP at one position in the circumferential direction, but is not limited to this, and the holder 90 may be constituted by a ring-shaped member having no opening.

Further, in the above-described embodiment, the holder 90 is constituted by one member, but is not limited to this, and the holder 90 may be constituted by a plurality of members (for example, a plurality of members arranged at intervals in the circumferential direction).

In the above embodiment, the rigidity of the retainer 90 is higher than the rigidity of the seal ring 80, but the present invention is not limited to this, and the rigidity of the retainer 90 may be equal to or lower than the rigidity of the seal ring 80.

Further, in the above embodiment, the holder 90 axially abuts against the annular surface SF over substantially the entire length thereof, but the present invention is not limited thereto, and the holder 90 may axially abut against the annular surface SF only over a part of the length thereof, or may be axially separated from the annular surface SF.

Further, in the above embodiment, the seal ring 80 is abutted against the stepped portion 1224 in the axial direction, but the present invention is not limited thereto, and the seal ring 80 may be separated from the stepped portion 1224 in the axial direction.

Further, in the above embodiment, the seal ring 80 is separated from the holder 90 in the axial direction, but the present invention is not limited to this, and the seal ring 80 may be abutted against the holder 90 in the axial direction.

In the above embodiment, the retainer 90 is in contact with the outer peripheral surface of the facing portion 1223 of the second housing 12 in the circumferential direction by the elastic restoring force, but the present invention is not limited to this, and the retainer 90 may be in contact with the inner peripheral surface of the second portion 111B of the first housing 11 in the circumferential direction by the elastic restoring force.

In the above embodiment, the holder 90 may be sandwiched between the inner peripheral surface of the second portion 111B of the first housing 11 and the outer peripheral surface of the facing portion 1223 of the second housing 12 (that is, the inner peripheral surface of the second portion 111B of the first housing 11 and the outer peripheral surface of the facing portion 1223 of the second housing 12 may abut against the holder 90).

In the above embodiment, the inner peripheral surface of the first portion 111A of the first housing 11 has an involute shape and the inner peripheral surface of the second portion 111B of the first housing 11 and the outer peripheral surface of the facing portion 1223 of the second housing 12 have circular shapes whose centers coincide with the center of the involute shape when viewed in the axial direction, but the present invention is not limited to this, and the inner peripheral surface of the first portion 111A of the first housing 11, the inner peripheral surface of the second portion 111B of the first housing 11, and the outer peripheral surface of the facing portion 1223 of the second housing 12 may have other shapes.

It should be understood that the present invention can freely combine the respective components in the embodiments, or appropriately change or omit the respective components in the embodiments within the scope thereof.

Claims (10)

1. A pump device comprising a housing having a first housing and a second housing constituting a pump chamber in which the impeller is rotatably housed, the first housing having a cylindrical first portion surrounding the impeller from an outer peripheral side and a cylindrical second portion located on one side in an axial direction of the first portion, an annular surface facing the one side in the axial direction being formed between the first portion and the second portion, and an impeller having a cylindrical facing portion facing the second portion on an inner peripheral side, a seal ring surrounding a rotation axis of the impeller being interposed between an inner peripheral surface of the second portion and an outer peripheral surface of the facing portion,

the annular surface has a narrow portion of minimum radial dimension,

a retainer is locked between an inner peripheral surface of the second portion and an outer peripheral surface of the opposing portion,

the retainer is located between the seal ring and the annular surface in the axial direction, and corresponds at least to the narrow width portion in the circumferential direction.

2. The pump apparatus of claim 1,

when viewed in the axial direction, the inner peripheral surface of the first portion has an involute shape.

3. The pump apparatus of claim 2,

the holder is generally annular in shape surrounding the rotational axis of the impeller.

4. Pump apparatus according to claim 3,

the holder is a split ring having an opening at one position in the circumferential direction.

5. The pump apparatus of claim 4,

the holder is abutted against an outer peripheral surface of the opposing portion or an inner peripheral surface of the second portion in the circumferential direction by an elastic restoring force.

6. The pump apparatus of claim 4,

the opening is located at a portion of the annular face where a radial dimension is largest.

7. The pump apparatus of claim 2,

the radial dimension of the annular surface gradually decreases toward one side in the circumferential direction.

8. The pump apparatus of claim 7,

an inner peripheral surface of the second portion and an outer peripheral surface of the opposing portion are each circular when viewed in the axial direction, the center of the inner peripheral surface coinciding with the center of the involute.

9. The pump apparatus of claim 2,

the retainer has a rigidity greater than that of the seal ring.

10. The pump apparatus of claim 2,

the second housing has a ring-shaped portion,

the annular portion is expanded from the facing portion toward an outer peripheral side and is axially abutted against an end surface of the second portion to perform axial positioning of the first housing with respect to the second housing,

a step part is arranged at the boundary of the annular part and the opposite part,

the seal ring is located axially between the step portion and the retainer,

the step portion is in contact with an inner peripheral surface of the second portion in a radial direction to perform radial positioning of the first housing with respect to the second housing.

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