CN112555163B

CN112555163B - Pump device

Info

Publication number: CN112555163B
Application number: CN202010932890.5A
Authority: CN
Inventors: 小窪信树; 山本岳; 仓谷大树
Original assignee: Nidec Sankyo Corp
Current assignee: Nidec Sankyo Corp
Priority date: 2019-09-10
Filing date: 2020-09-08
Publication date: 2023-01-31
Anticipated expiration: 2040-09-08
Also published as: JP7373327B2; JP2021042706A; CN212536099U; CN112555163A

Abstract

A pump device is provided with a housing having a first housing and a second housing that are combined in an axial direction of a rotor and having a pump chamber formed therein, and an O-ring that is disposed between the first housing and the second housing in a radial direction of the rotor, wherein twisting of the O-ring during assembly can be suppressed. In the pump device, a first housing (7) is provided with a limiting surface (11 p) for limiting downward movement of an O-ring (10), a contact surface (11 j) for contacting the O-ring, and a positioning surface (11 k) for positioning a second housing (8) in the radial direction with respect to the first housing, and the second housing is provided with a contact surface (8 c) for contacting the O-ring and a positioning surface (8 d) for contacting the positioning surface. A distance (L1) between the center of the O-ring and the upper end of the positioning surface when the O-ring in contact with the limiting surface (11 p) is not elastically deformed is longer than a distance (L2) between the lower end of the contact surface and the lower end of the positioning surface (8 d).

Description

Pump device

Technical Field

The present invention relates to a pump device including an O-ring for preventing fluid from leaking from a pump chamber.

Background

Conventionally, a pump device including an impeller and a motor for rotating the impeller is known (for example, see patent document 1). In the pump device described in patent document 1, the impeller and the motor are disposed inside a housing including a casing and an upper housing covering an upper portion of the casing. The upper case is provided with a fluid suction portion and a fluid discharge portion. A pump chamber through which fluid sucked from the suction portion passes toward the discharge portion is formed between the outer casing and the upper case. The motor includes a rotor disposed in the pump chamber and a stator disposed outside the pump chamber.

In the pump device described in patent document 1, an O-ring for preventing leakage of fluid from the pump chamber is disposed at a joint portion between the housing and the upper housing. The O-ring is disposed between the outer casing and the upper housing in the axial direction of the rotor. The housing and the upper case are fixed to each other by screws. The axial direction of the screw is consistent with the axial direction of the rotor, and when the shell and the upper shell are fixed with each other through the screw, the O-shaped ring is extruded in the axial direction of the rotor, so that the sealing performance of the O-shaped ring is ensured.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2017-216758

Disclosure of Invention

Technical problems to be solved by the invention

In the case of the pump device described in patent document 1, when the pump device is used in an environment where vibration is likely to occur, the screws that fix the housing and the upper case may loosen due to the influence of the vibration of the pump device. In the pump device described in patent document 1, when the pump device vibrates and the screw fixing the housing and the upper housing is loosened, the amount of pressing of the O-ring in the axial direction of the rotor decreases, and there is a possibility that the sealing performance of the O-ring is lowered.

Therefore, the inventors of the present application have studied a technique of disposing an O-ring between a housing and an upper housing in a radial direction of a rotor. For example, it has been studied to arrange an O-ring between a housing and an upper housing in a radial direction of a rotor so that an inner peripheral surface of the O-ring contacts with an O-ring contact surface of the housing and an outer peripheral surface of the O-ring contacts with an O-ring contact surface of the upper housing. In this case, since the O-ring is pressed in the radial direction of the rotor, even if the pump device vibrates so that the screw fixing the housing and the upper housing is loosened, the pressing amount of the O-ring in the radial direction of the rotor does not change. Therefore, even if the pump device vibrates so that the screw fixing the housing and the upper case loosens, the sealing performance of the O-ring can be ensured.

When the O-ring is disposed between the housing and the upper housing in the radial direction of the rotor, the housing is formed by, for example, combining the upper housing with the housing to which the O-ring is attached in the axial direction of the rotor. Further, in the case where the O-ring is arranged between the housing and the upper housing in the radial direction of the rotor, in order to press the O-ring by a predetermined amount in the radial direction of the rotor, when the upper housing is assembled to the housing in the axial direction of the rotor, it is necessary to move the upper housing relative to the housing in the axial direction of the rotor while bringing the O-ring contact surface of the upper housing into contact with the outer peripheral surface of the O-ring at a predetermined contact pressure.

However, when the upper housing is moved in the axial direction of the rotor relative to the housing while the O-ring contact surface of the upper housing is brought into contact with the outer peripheral surface of the O-ring at a predetermined contact pressure, if the contact pressures of the O-ring contact surface of the upper housing and the outer peripheral surface of the O-ring do not match in the circumferential direction of the O-ring, the O-ring may be twisted when the housing is formed. That is, the O-ring may be distorted when the pump device is assembled. In addition, if the O-ring is distorted, the sealing performance of the O-ring may be reduced.

Accordingly, an object of the present invention is to provide a pump device including a housing having a first housing and a second housing combined in an axial direction of a rotor and having a pump chamber formed therein, and an O-ring disposed between the first housing and the second housing in a radial direction of the rotor, wherein the O-ring can be prevented from being twisted during assembly.

Technical scheme for solving technical problem

In order to solve the above-described problems, a pump device according to the present invention includes: a motor having a rotor and a stator; the impeller is arranged on the rotor; a housing in which a pump chamber through which a fluid passes is formed, the pump chamber having a rotor and an impeller arranged therein; and an O-ring for preventing a fluid from leaking from the pump chamber, wherein the housing includes a first housing and a second housing that are combined in an axial direction of the rotor, the O-ring is disposed between the first housing and the second housing in a radial direction of the rotor, and if one of the axial directions is a first direction and an opposite direction of the first direction is a second direction, the first housing is formed with: a restricting surface for restricting movement of the O-ring to a first direction side; a first contact surface that is in contact with either an O-ring inner peripheral surface that is an inner peripheral surface of an O-ring or an O-ring outer peripheral surface that is an outer peripheral surface of the O-ring; and a first positioning surface for positioning the second housing in a radial direction with respect to the first housing, the second housing having formed thereon: a second contact surface that is in contact with either the inner peripheral surface of the O-ring or the outer peripheral surface of the O-ring; and a second positioning surface that is in contact with the first positioning surface and positions the second housing in a radial direction with respect to the first housing, wherein the restricting surface is a plane orthogonal to the axial direction, the first positioning surface is disposed at a position closer to the second direction side than the restricting surface and the first contact surface, the second positioning surface is disposed at a position closer to the second direction side than the second contact surface, and an axial distance between a center of the O-ring in the axial direction and a second direction end of the first positioning surface when the O-ring in contact with the restricting surface is not elastically deformed is longer than an axial distance between the first direction end of the second contact surface and the first direction end of the second positioning surface.

In the pump device of the present invention, the first housing is formed with: a restricting surface for restricting movement of the O-ring to a first direction side; a first contact surface that is in contact with either the inner peripheral surface of the O-ring or the outer peripheral surface of the O-ring; and a first positioning surface for positioning the second housing in a radial direction with respect to the first housing, the second housing having formed thereon: a second contact surface that is in contact with either the inner peripheral surface of the O-ring or the outer peripheral surface of the O-ring; and a second positioning surface contacting the first positioning surface and positioning the second housing in a radial direction with respect to the first housing. In the present invention, the axial distance between the center of the O-ring in the axial direction and the second direction end of the first positioning surface when the O-ring in contact with the regulating surface is not elastically deformed is longer than the axial distance between the first direction end of the second contact surface and the first direction end of the second positioning surface.

Therefore, in the present invention, when the second housing is moved to the first direction side with respect to the first housing in a state in which the O-ring in contact with the regulation surface is attached, and the second housing is assembled to the first housing in the axial direction, when the second contact surface of the second housing is brought into contact with the O-ring and presses the O-ring in the radial direction (that is, when the second contact surface is brought into contact with the O-ring at a predetermined contact pressure), the first positioning surface and the second positioning surface can be brought into contact with each other, and the second housing can be positioned in the radial direction with respect to the first housing. Therefore, in the present invention, when the second housing is assembled to the first housing in the axial direction, the second housing can be moved to the first direction side with respect to the first housing while the second contact surface is brought into contact with the O-ring at a predetermined contact pressure in a state where the second housing is positioned in the radial direction with respect to the first housing.

As a result, in the present invention, when the second housing is moved to the first direction side with respect to the first housing while the second contact surface is brought into contact with the O-ring at a predetermined contact pressure, and the second housing is axially combined with the first housing, it is possible to suppress the contact pressure between the second contact surface and the O-ring from being inconsistent in the circumferential direction of the O-ring. Therefore, in the present invention, the O-ring can be prevented from being twisted when the pump device is assembled.

In the present invention, for example, the second contact surface is arranged radially outside the first contact surface, the inner peripheral surface of the O-ring is in contact with the first contact surface, the outer peripheral surface of the O-ring is in contact with the second contact surface, and the second positioning surface is arranged radially outside the first positioning surface and is in contact with the first positioning surface from radially outside.

In the present invention, for example, the first contact surface and the first positioning surface are formed on the same curved surface. In this case, the structure of the first housing can be simplified as compared with a case where the first contact surface and the first positioning surface are not formed on the same curved surface.

In the present invention, it is preferable that the first housing has a first housing regulation surface for regulating movement of the second housing in the first direction, the second housing has a second housing regulation surface in contact with the first housing regulation surface for regulating movement of the second housing in the first direction, the first housing regulation surface and the second housing regulation surface are planes perpendicular to the axial direction, the first housing regulation surface is disposed on the first direction side of the regulation surface, the second housing regulation surface is disposed on the first direction side of the second contact surface, the second housing regulation surface is formed on the second housing, a chamfered portion for connecting the second housing regulation surface and the second contact surface is formed, and the axial distance between the first housing regulation surface and the regulation surface is longer than the axial distance between the second housing regulation surface and the first direction end of the second contact surface.

With this configuration, since the chamfered portion that connects the second housing regulating surface and the second contact surface is formed on the second housing, when the second housing is moved to the first direction side with respect to the first housing and the second housing is assembled to the first housing in the axial direction, the O-ring can be gradually pressed by the chamfered portion. In addition, in the case of the above configuration, since the axial distance between the first housing regulating surface and the regulating surface is longer than the axial distance between the second housing regulating surface and the first direction end of the second contact surface, the O-ring is not disposed at a position where the chamfered portion is formed in the axial direction. Therefore, even if the chamfered portion connecting the second housing regulating surface and the second contact surface is formed in the second housing, the amount of pressing of the O-ring in the radial direction can be prevented from being reduced by the influence of the chamfered portion.

In the present invention, it is preferable that the stator is formed in a cylindrical shape, is disposed on an outer peripheral side of the rotor, and is disposed outside the pump chamber, the first housing includes a partition wall member that defines a part of the pump chamber and is disposed between the pump chamber and the stator, and a resin seal member made of a resin that covers the stator, the partition wall member is formed with a cylindrical tube portion, the first contact surface constitutes at least a part of an outer peripheral surface of the tube portion, and an inner peripheral side of the tube portion is filled with a part of the resin seal member.

With this configuration, even if a large fluid pressure acts on the first contact surface with which the inner peripheral surface of the O-ring comes into contact, the cylindrical portion of the resin seal member, which constitutes at least a part of the outer peripheral surface of the first contact surface, can be prevented from being deformed inward in the radial direction. Therefore, even if a large pressure of the fluid acts on the first contact surface, a reduction in the amount of pressing of the O-ring in the radial direction can be suppressed, and as a result, the sealing performance of the O-ring can be ensured.

Effects of the invention

As described above, in the present invention, a pump device is provided with a housing having a first housing and a second housing combined in an axial direction of a rotor and having a pump chamber formed therein, and an O-ring disposed between the first housing and the second housing in a radial direction of the rotor, wherein the O-ring can be prevented from being twisted when the pump device is assembled.

Drawings

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

Fig. 2 (a) and 2 (B) are enlarged views for explaining the structure of the section E in fig. 1.

Description of the reference numerals

1 \ 8230a pump device; 2 \ 8230and an impeller; 3 \ 8230and motor; 5\8230anda rotor; 6 \ 8230and stator; 7 \ 8230and a shell (a first shell); 8 \ 8230and an upper shell (a second shell); 8c 8230and a contact surface (second contact surface); 8d 8230and a positioning surface (a second positioning surface); 8e 8230and a limiting surface (a second shell limiting surface); 8f 8230and chamfered parts; 9\8230apump chamber; 10\8230aO-shaped ring; 10a 8230and the inner peripheral surface of an O-shaped ring; 10b 8230and the peripheral surface of an O-shaped ring; 11 \ 8230and partition wall parts; 11g 8230a cylindrical part; 11j 8230and a contact surface (first contact surface); 11k \8230anda positioning surface (a first positioning surface); 11n 8230and a limiting surface (a first shell limiting surface); 11 p\8230anda limiting surface; 12 8230a resin sealing member; 13 \ 8230and a shell; l1 \ 8230, the axial distance between the center of the O-shaped ring in the axial direction and the second direction end of the first positioning surface; l2 \8230theaxial distance between the first direction end of the second contact surface and the first direction end of the second positioning surface; l3 \ 8230and the axial distance between the first shell limiting surface and the limiting surface; l4 \ 8230and the axial distance between the second housing limiting surface and the first direction end of the second contact surface; z \8230inaxial direction; z1 (8230); second direction; z2 (8230); first direction.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(integral construction of Pump device)

Fig. 1 is a sectional view of a pump device 1 according to an embodiment of the present invention. In the following description, the Z direction in fig. 1 is referred to as the "up-down direction", the Z1 direction in fig. 1, which is one of the up-down directions, is referred to as the "up direction", and the Z2 direction in fig. 1, which is the opposite of the up direction, is referred to as the "down direction".

The pump device 1 of the present embodiment is a centrifugal pump of a type called a canned motor pump (canned motor pump), and includes an impeller 2, a motor 3 for rotating the impeller 2, and a circuit board 4 for controlling the motor 3. The motor 3 includes a rotor 5 and a stator 6. The impeller 2, the motor 3, and the circuit board 4 are disposed inside a casing 13, and the casing 13 includes a casing 7 and an upper casing 8 covering an upper portion of the casing 7. The housing 7 and the upper case 8 are fixed to each other by screws not shown.

The upper case 8 is formed with a fluid suction portion 8a and a fluid discharge portion 8b. A pump chamber 9 through which the fluid sucked from the suction portion 8a passes toward the discharge portion 8b is formed between the casing 7 and the upper case 8. That is, the pump chamber 9 is formed inside the housing 13. An O-ring 10 for ensuring the sealing performance of the pump chamber 9 and preventing fluid from leaking from the pump chamber 9 is disposed at the joint portion between the housing 7 and the upper case 8. The housing 7 includes a partition member 11 and a resin sealing member 12, the partition member 11 having a partition wall 11a disposed between the pump chamber 9 and the stator 6 so as to partition the pump chamber 9 and the stator 6, the resin sealing member 12 covering a lower surface and a side surface of the partition member 11.

The rotor 5 includes a driving magnet 14, a cylindrical sleeve 15, and a holding member 16 that holds the driving magnet 14 and the sleeve 15. The holding member 16 is formed in a substantially cylindrical shape with a flange. The driving magnet 14 is fixed to the outer peripheral side of the holding member 16, and the sleeve 15 is fixed to the inner peripheral side of the holding member 16. The impeller 2 is fixed to the flange portion 16a of the holding member 16 disposed on the upper side. That is, the impeller 2 is mounted on the rotor 5. The impeller 2 and the rotor 5 are disposed in the pump chamber 9. In the following description, the radial direction of the rotor 5 is referred to as the "radial direction", and the circumferential direction (circumferential direction) of the rotor 5 is referred to as the "circumferential direction".

The rotor 5 is rotatably supported by a fixed shaft 17. The fixed shaft 17 is disposed so that the axial direction of the fixed shaft 17 coincides with the vertical direction. That is, the vertical direction is the axial direction of the rotor 5. The upper end of the fixed shaft 17 is held by the upper case 8, and the lower end of the fixed shaft 17 is held by the housing 7. The fixed shaft 17 is inserted through the inner peripheral side of the sleeve 15. Further, a thrust bearing member 18 is attached to the fixed shaft 17 so as to abut on the upper end surface of the sleeve 15. In the present embodiment, the sleeve 15 functions as a radial bearing of the rotor 5, and the sleeve 15 and the thrust bearing member 18 function as a thrust bearing of the rotor 5. The lower direction (Z2 direction) in the present embodiment is a first direction which is one of the axial directions of the rotor 5, and the upper direction (Z1 direction) is a second direction which is the opposite direction of the first direction.

The stator 6 includes a driving coil 23, a stator core 24, and an insulator 25, and is formed in a cylindrical shape as a whole. Specifically, the stator 6 is formed in a substantially cylindrical shape. The stator 6 is disposed on the outer circumferential side of the rotor 5 via the partition wall 11a. The stator 6 is disposed outside the pump chamber 9. The stator 6 is disposed so that the axial direction of the stator 6 coincides with the vertical direction.

The stator core 24 is a laminated core formed by laminating thin magnetic plates made of a magnetic material. The stator core 24 includes an outer circumferential ring 24a formed in an annular shape and a plurality of salient pole portions 24b protruding radially inward from the outer circumferential ring 24 a. The outer peripheral surface of the outer peripheral ring portion 24a constitutes the outer peripheral surface of the stator core 24. The projecting tip portion constituting the tip portion of the projecting tip portion 24b faces the outer peripheral surface of the driving magnet 14 via the partition wall 11a. An insulator 25 is mounted to each tab 24b. The driving coil 23 is made of a conductive wire made of copper alloy or the like. The driving coil 23 is wound around each of the plurality of salient pole portions 24b via an insulator 25.

As described above, the partition member 11 includes the partition wall 11a. The partition wall 11a is formed in a substantially bottomed cylindrical shape with a flange, and includes a cylindrical portion 11b, a bottom portion 11c, and a flange portion 11d. The cylindrical portion 11b is formed in a cylindrical shape, and covers the outer peripheral surface of the driving magnet 14. The cylindrical portion 11b is disposed radially between the rotor 5 and the stator 6. The axial center of the cylindrical portion 11b coincides with the axial center of the fixed shaft 17. The bottom portion 11c is formed in a disc shape that closes the lower end of the cylindrical portion 11 b. The flange portion 11d is formed to expand radially outward from the upper end of the cylindrical portion 11 b.

As shown in fig. 1, the pump chambers 9 are formed inside and above the partition wall 11a, and the impeller 2 and the rotor 5 are disposed inside and above the partition wall 11a. The partition wall 11a defines a part of the pump chamber 9. That is, the partition member 11 defines a part of the pump chamber 9. The partition wall 11a functions to prevent the fluid in the pump chamber 9 from flowing into the stator 6 and the circuit board 4.

The circuit board 4 is a rigid substrate such as a glass epoxy substrate, and is formed in a flat plate shape. The circuit board 4 is fixed to the partition wall 11a in a state where the thickness direction of the circuit board 4 coincides with the vertical direction. The circuit board 4 is fixed to the lower end side portion of the partition wall 11a.

The resin sealing member 12 is formed of BMC (Bulk Molding Compound). The resin sealing member 12 covers the stator 6 and the circuit board 4. The resin sealing member 12 functions to protect the circuit board 4, the driving coil 23, and the like from the fluid. The resin sealing member 12 is formed in a substantially bottomed cylindrical shape as a whole, and completely covers the stator 6, the cylindrical portion 11b, and the bottom portion 11c. Further, the resin sealing member 12 covers substantially the entire circuit board 4 and the lower surface of the flange portion 11d.

(Structure of peripheral part of O-ring)

As described above, the O-ring 10 is disposed at the joint portion of the housing 7 and the upper housing 8. The housing 7 and the upper case 8 are combined in the vertical direction and fixed to each other. That is, the case 13 includes the casing 7 and the upper case 8 combined in the vertical direction, and the casing 7 and the upper case 8 can be divided in the vertical direction. The O-ring 10 is disposed radially between the outer shell 7 and the upper housing 8. The O-ring 10 is pressed by a predetermined amount in the radial direction. The housing 7 of the present embodiment is a first case, and the upper case 8 is a second case.

As described above, the housing 7 includes the partition member 11 having the partition wall 11a. The partition wall 11a includes a flange portion 11d extending radially outward from the upper end of the cylindrical portion 11 b. The flange portion 11d includes an annular flat plate-like first flange portion 11f extending radially outward from the upper end of the cylindrical portion 11b, a cylindrical portion 11g protruding downward from the outer peripheral end of the first flange portion 11f, and an annular flat plate-like second flange portion 11h extending radially outward from the lower end of the cylindrical portion 11 g. The axis of the cylindrical portion 11g coincides with the axis of the fixed shaft 17. As described above, the resin sealing member 12 covers the lower surface of the flange portion 11d. Therefore, a part of the resin seal member 12 is filled in the inner peripheral side of the tube portion 11 g. That is, a part of the resin seal member 12 is filled between the cylindrical portion 11b and the cylindrical portion 11g in the radial direction.

The lower part of the outer peripheral surface of the tube part 11g is a contact surface 11j with which an O-ring inner peripheral surface 10a, which is the inner peripheral surface of the O-ring 10, contacts. An upper portion of the outer peripheral surface of the cylindrical portion 11g is a positioning surface 11k for positioning the upper case 8 in the radial direction with respect to the housing 7. That is, the contact surface 11j and the positioning surface 11k are formed on the same curved surface. The positioning surface 11k is arranged above the contact surface 11j. The contact surface 11j of the present embodiment is a first contact surface, and the positioning surface 11k is a first positioning surface.

The upper surface of the first flange portion 11f is a plane orthogonal to the vertical direction. The upper surface of the second flange portion 11h is a plane orthogonal to the vertical direction. The upper surface of second flange portion 11h is a regulating surface 11n for regulating downward movement of upper case 8. The regulating surface 11n of the present embodiment is a first case regulating surface.

A regulating surface 11p for regulating the downward movement of the O-ring 10 is formed at the boundary between the cylindrical portion 11g and the second flange portion 11h. The regulating surface 11p is formed on the outer peripheral side of the cylindrical portion 11 g. The restriction surface 11p is a plane orthogonal to the vertical direction. The regulating surface 11p is formed in an annular shape. The inner peripheral end of the regulating surface 11p is connected to the lower end of the contact surface 11j. That is, the contact surface 11j is arranged above the restricting surface 11p. The regulating surface 11p is disposed above the regulating surface 11n. That is, the regulating surface 11n is disposed below the regulating surface 11p.

A contact surface 8c is formed on the inner peripheral side of the upper housing 8, with which an O-ring outer peripheral surface 10b, which is the outer peripheral surface of the O-ring 10, is in contact. The contact surface 8c is formed at the lower end portion of the upper case 8. The contact surface 8c is a cylindrical surface having a circular shape when viewed in the vertical direction. The contact surface 8c is disposed radially outward of the contact surface 11j and faces the contact surface 11j in the radial direction. The contact surface 8c of the present embodiment is a second contact surface.

Further, a positioning surface 8d that contacts the positioning surface 11k and positions the upper case 8 in the radial direction with respect to the housing 7 is formed on the inner peripheral side of the upper case 8. The positioning surface 8d is disposed above the contact surface 8c. The positioning surface 8d is a cylindrical surface having a circular shape when viewed in the vertical direction. The inner diameter of the positioning surface 8d is smaller than the inner diameter of the contact surface 8c. The contact surface 8c and the positioning surface 8d are concentrically arranged. The positioning surface 8d is arranged radially outside the positioning surface 11k and contacts the positioning surface 11k from radially outside. The positioning surface 8d of the present embodiment is a second positioning surface.

The lower end surface of the upper case 8 is an annular flat surface perpendicular to the vertical direction. The lower end surface of the upper case 8 is a regulating surface 8e that is in contact with the regulating surface 11n and regulates the downward movement of the upper case 8. The regulating surface 8e is disposed below the contact surface 8c. The regulating surface 8e of the present embodiment is a second housing regulating surface. A chamfered portion 8f connecting the regulating surface 8e and the contact surface 8c is formed on the inner peripheral side of the upper case 8. The chamfered portion 8f is an inclined surface formed by chamfering. The upper end of the chamfered portion 8f is connected to the lower end of the contact surface 8c, and the lower end of the chamfered portion 8f is connected to the inner peripheral end of the regulating surface 8e.

Further, a stepped surface 8g connected to an upper end of the contact surface 8c is formed on the inner peripheral side of the upper case 8. The step surface 8g is a plane orthogonal to the vertical direction. The step surface 8g is formed in an annular shape. The outer peripheral end of the step face 8g is connected to the contact face 8c. Further, a chamfered portion 8h connecting the step surface 8g and the positioning surface 8d is formed on the inner peripheral side of the upper case 8. The chamfered portion 8h is an inclined surface formed by chamfering. The upper end of the chamfered portion 8h is connected to the lower end of the positioning surface 8d, and the lower end of the chamfered portion 8h is connected to the inner peripheral end of the step surface 8g.

In the present embodiment, a vertical distance L1 between the center of the O-ring 10 and the upper end of the positioning surface 11k in the vertical direction when the O-ring 10 in contact with the regulating surface 11p is not elastically deformed (see the two-dot chain line in fig. 2 a) is longer than a vertical distance L2 between the lower end of the contact surface 8c and the lower end of the positioning surface 8d. In the present embodiment, the vertical distance L3 between the regulating surface 11n and the regulating surface 11p is longer than the vertical distance L4 between the regulating surface 8e and the lower end of the contact surface 8c (i.e., the vertical length of the chamfered portion 8 f).

(assembling step of Pump device)

In the present embodiment, the cylindrical portion 11b of the partition member 11 is inserted into the inner circumferential side of the stator 6, the stator 6 is mounted on the partition member 11, the circuit board 4 is fixed to the partition member 11, the partition member 11 to which the circuit board 4 and the stator 6 are fixed is then placed in a mold, and a resin material is injected into the mold and cured to form the resin seal member 12. After that, the rotor 5 is disposed on the inner circumferential side of the cylindrical portion 11b, and the impeller 2 is fixed to the holding member 16. Then, the O-ring 10 is attached to the outer peripheral surface of the cylindrical portion 11g such that the lower end of the O-ring 10 contacts the restricting surface 11p. In this state, the upper case 8 is moved downward with respect to the housing 7, and the upper case 8 and the housing 7 are combined. Thereafter, the upper case 8 is fixed to the housing 7 with screws, thereby completing the pump apparatus 1.

As described above, the vertical distance L1 between the center of the O-ring 10 and the upper end of the positioning surface 11k in the vertical direction when the O-ring 10 in contact with the regulating surface 11p is not elastically deformed is longer than the vertical distance L2 between the lower end of the contact surface 8c and the lower end of the positioning surface 8d. Therefore, when the upper housing 8 is moved to the lower side with respect to the housing 7 and the upper housing 8 is combined with the housing 7, as shown in fig. 2 (B), when the contact surface 8c comes into contact with the O-ring 10 and the O-ring 10 is pressed to the inside in the radial direction (i.e., when the contact surface 8c comes into contact with the O-ring 10 at a predetermined contact pressure), the positioning surface 11k comes into contact with the positioning surface 8d, and the upper housing 8 is positioned in the radial direction with respect to the housing 7.

(main effect of the present embodiment)

As described above, in the present embodiment, the distance L1 is longer than the distance L2, and when the upper case 8 is moved to the lower side with respect to the housing 7 and the upper case 8 is combined with the housing 7, the positioning surface 11k and the positioning surface 8d come into contact with each other when the contact surface 8c comes into contact with the O-ring 10 and presses the O-ring 10 radially inward (that is, when the contact surface 8c comes into contact with the O-ring 10 at a predetermined contact pressure), and the upper case 8 is positioned radially with respect to the housing 7.

Therefore, in the present embodiment, when the upper housing 8 and the outer housing 7 are combined, the upper housing 8 can be moved downward with respect to the outer housing 7 while the contact surface 8c is brought into contact with the O-ring 10 at a predetermined contact pressure in a state where the upper housing 8 is positioned in the radial direction with respect to the outer housing 7. Therefore, in the present embodiment, when the upper housing 8 is moved to the lower side with respect to the housing 7 while the contact surface 8c is brought into contact with the O-ring 10 at a predetermined contact pressure and the upper housing 8 is combined with the housing 7, it is possible to suppress variation in the contact pressure between the contact surface 8c and the O-ring 10 in the circumferential direction. Therefore, in the present embodiment, the O-ring 10 can be prevented from being twisted when the pump device 1 is assembled.

In the present embodiment, a chamfered portion 8f that connects the regulating surface 8e and the contact surface 8c is formed on the inner peripheral side of the upper case 8. Therefore, in the present embodiment, when the upper case 8 is moved to the lower side with respect to the housing 7 and the upper case 8 is combined with the housing 7, the O-ring 10 can be gradually pressed by the chamfered portion 8f. In the present embodiment, since the vertical distance L3 between the regulating surface 11n and the regulating surface 11p is longer than the vertical distance L4 between the regulating surface 8e and the lower end of the contact surface 8c, the O-ring 10 is not disposed at the position where the chamfered portion 8f is formed in the vertical direction as shown in fig. 2 (a). Therefore, in the present embodiment, even if the chamfered portion 8f is formed in the upper housing 8, the amount of pressing in the radial direction of the O-ring 10 can be prevented from being reduced by the influence of the chamfered portion 8f.

In the present embodiment, a part of the resin seal member 12 is filled in the inner peripheral side of the tube portion 11g where the contact surface 11j constitutes a part of the outer peripheral surface. Therefore, in the present embodiment, even if a large fluid pressure acts on the contact surface 11j with which the O-ring inner peripheral surface 10a is in contact, the cylindrical portion 11g can be prevented from being deformed inward in the radial direction by a part of the resin seal member 12. Therefore, in the present embodiment, even if a large fluid pressure acts on the contact surface 11j, a decrease in the amount of the O-ring 10 pressed in the radial direction can be suppressed, and as a result, the sealing performance of the O-ring 10 can be ensured.

(other embodiments)

The above-described embodiment is an example of the best mode of the present invention, but is not limited thereto, and various modifications can be made within a range not changing the gist of the present invention.

In the above embodiment, the partition member 11 may be formed with a first contact surface with which the O-ring outer peripheral surface 10b contacts, and the upper housing 8 may be formed with a second contact surface with which the O-ring inner peripheral surface 10a contacts. In this case, the second contact surface is disposed radially inward of the first contact surface. In this case, a first positioning surface corresponding to the positioning surface 11k is formed on the partition member 11, and a second positioning surface corresponding to the positioning surface 8d is formed on the upper case 8. The second positioning surface is disposed radially inward of the first positioning surface and contacts the first positioning surface from radially inward.

In the above-described embodiment, the contact surface 11j and the positioning surface 11k may not be formed on the same curved surface. Specifically, the outer diameter of the positioning surface 11k may be smaller than the outer diameter of the contact surface 11j. In the above-described embodiment, the motor 3 is an inner rotor type motor in which the rotor 5 is disposed on the inner peripheral side of the stator 6, but the motor 3 may be an outer rotor type motor in which the rotor is disposed on the outer peripheral side of the stator.

In the above embodiment, the chamfered portion 8f may be formed by rounding. In the above-described embodiment, the housing 7 and the upper case 8 may be fixed by fixing means other than screws. For example, the housing 7 and the upper case 8 may be fixed by a snap fastener that is elastically deformed by an elastic piece formed on the housing 7 or the upper case 8. In the above embodiment, the impeller 2 may be formed integrally with the rotor 5. For example, the impeller 2 may be formed integrally with the holding member 16.

Claims

1. A pump device, characterized in that it comprises a pump body,

the disclosed device is provided with: an electric motor having a rotor and a stator; an impeller mounted on the rotor; a housing in which a pump chamber through which a fluid passes is formed, the pump chamber having the rotor and the impeller arranged therein; and an O-ring for preventing fluid from leaking out of the pump chamber,

the housing includes a first housing and a second housing that are combined in an axial direction of the rotor,

the O-ring is disposed between the first housing and the second housing in a radial direction of the rotor,

if one of the axial directions is set as a first direction and the opposite direction of the first direction is set as a second direction, then

The first housing is formed with: a restricting surface for restricting movement of the O-ring to a first direction side; a first contact surface that is in contact with either an O-ring inner peripheral surface that is an inner peripheral surface of the O-ring or an O-ring outer peripheral surface that is an outer peripheral surface of the O-ring; and a first positioning face for positioning the second housing in the radial direction with respect to the first housing,

the second housing is formed with: a second contact surface that is in contact with either the O-ring inner peripheral surface or the O-ring outer peripheral surface; and a second positioning surface that is in contact with the first positioning surface, positions the second housing in the radial direction with respect to the first housing,

the limiting surface is a plane orthogonal to the axial direction,

the first positioning surface is disposed on a second direction side with respect to the restricting surface and the first contact surface,

the second positioning surface is disposed on a second direction side with respect to the second contact surface,

the axial distance between the center of the O-ring in the axial direction and a second direction end of the first positioning surface when the O-ring in contact with the restraining surface is not elastically deformed is longer than the axial distance between a first direction end of the second contact surface and a first direction end of the second positioning surface.

2. Pump arrangement according to claim 1,

the second contact surface is disposed outside the first contact surface in the radial direction,

the inner peripheral surface of the O-shaped ring is contacted with the first contact surface,

the outer peripheral surface of the O-shaped ring is contacted with the second contact surface,

the second positioning surface is disposed outside the first positioning surface in the radial direction, and contacts the first positioning surface from the outside in the radial direction.

3. Pump apparatus according to claim 1,

the first contact surface and the first positioning surface are formed on the same curved surface.

4. Pump apparatus according to claim 2,

5. Pump device according to any one of claims 1 to 4,

a first housing regulating surface for regulating the movement of the second housing toward the first direction side is formed on the first housing,

a second housing regulating surface that is formed on the second housing, the second housing regulating surface being in contact with the first housing regulating surface and regulating movement of the second housing toward the first direction side,

the first housing restriction surface and the second housing restriction surface are planes orthogonal to the axial direction,

the first housing regulating surface is disposed on a first direction side of the regulating surface,

the second housing restriction surface is disposed on the first direction side of the second contact surface,

a chamfered portion connecting the second housing regulation surface and the second contact surface is formed on the second housing,

the axial distance between the first housing restriction surface and the restriction surface is longer than the axial distance between the second housing restriction surface and a first direction end of the second contact surface.

6. Pump apparatus according to claim 2,

the stator is formed in a cylindrical shape, is disposed on an outer peripheral side of the rotor, and is disposed outside the pump chamber,

the first housing includes a partition member that defines a part of the pump chamber and is disposed between the pump chamber and the stator, and a resin sealing member that covers the stator,

a cylindrical tube portion is formed in the partition member, the first contact surface constituting at least a part of an outer peripheral surface of the tube portion,

the inner circumferential side of the cylinder portion is filled with a part of the resin seal member.