WO2018047602A1

WO2018047602A1 - Pump motor

Info

Publication number: WO2018047602A1
Application number: PCT/JP2017/029603
Authority: WO
Inventors: 友治中村; 雄一山本
Original assignee: 日本電産テクノモータ株式会社
Priority date: 2016-09-09
Filing date: 2017-08-18
Publication date: 2018-03-15
Also published as: JP2019198131A

Abstract

This pump motor is provided with: a rotor which rotates around a rotational axis that extends in the vertical direction; a stator which is provided outside the rotor in the radial direction; and a cylindrical stator can which is provided to the inner circumferential side of the stator, surrounds the rotor, and extends in the axial direction. The stator can is provided with ribs which protrude from the circumferential surface in the radial direction, and which extend in the axial direction.

Description

Pump motor

The present invention relates to a pump motor.

Conventionally, a motor in which a rotor having a magnet and a shaft is arranged radially inside an annular stator having an exciting coil is widely known. Furthermore, a pump motor in which a stator can is provided on a stator is known. A technique related to a pump motor is disclosed in Patent Document 1. *

The conventional canned motor pump described in Patent Document 1 includes a substantially cylindrical stator can provided on the inner peripheral surface of the stator and a substantially cylindrical rotor can provided on the outer peripheral surface of the rotor. The stator can surrounds the inner peripheral surface of the stator in a watertight manner. The rotor can surrounds the outer peripheral surface of the rotor in a watertight manner. With this configuration, it is possible to prevent liquid from entering the stator and the rotor from the region of the gap between the stator and the rotor. Therefore, the canned motor pump can be properly operated as a pump.

JP 2002-213385 A

However, the conventional canned motor pump described in Patent Document 1 does not give sufficient consideration to the high pressure that may occur in the gap between the rotor and the stator. In other words, this conventional canned motor pump has a problem that the stator can does not have sufficient strength, and the canned motor pump may not be stably operated. *

The present invention has been made in view of the above points, and an object of the present invention is to provide a pump motor that can improve the strength of the stator can and can operate the pump stably.

An exemplary pump motor according to the present invention includes a rotor that rotates about a rotary shaft that extends in a vertical direction, a stator that is disposed radially outward of the rotor, and an inner circumferential side of the stator that is disposed on the rotor And a cylindrical stator can extending in the axial direction. The stator can has a rib extending in the radial direction from the peripheral surface and extending in the axial direction.

According to the exemplary pump motor of the present invention, the strength of the stator can is improved. As a result, even when a high pressure is generated in the gap between the rotor and the stator, the pump can be operated stably.

FIG. 1 is a vertical end view of a cutting part of a pump motor according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of the pump motor according to the embodiment of the present invention. FIG. 3 is an external perspective view of the stator can of the pump motor according to the embodiment of the present invention. FIG. 4 is a partially enlarged plan view of the pump motor according to the embodiment of the present invention. FIG. 5 is a partially enlarged external perspective view of the stator can of the pump motor according to the embodiment of the present invention. FIG. 6 is a partially enlarged cross-sectional perspective view of the pump motor according to the embodiment of the present invention. FIG. 7 is a vertical end view of a partially enlarged cut portion of the pump motor according to the embodiment of the present invention. FIG. 8 is a partially enlarged external perspective view of the stator can of the pump motor according to the embodiment of the present invention. FIG. 9 is a cross-sectional perspective view of a first modification of the pump motor according to the embodiment of the present invention. FIG. 10 is an external perspective view of a stator can of a second modification of the pump motor according to the embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this document, the direction in which the rotating shaft of the pump motor extends is simply called the “axial direction”, and the direction perpendicular to the rotating shaft around the rotating shaft of the pump motor is simply called the “radial direction”. The direction along the arc centered on the axis is simply referred to as “circumferential direction”. Further, in this document, for convenience of explanation, the shape and positional relationship of each part will be described with the axial direction as the vertical direction and the vertical direction in FIG. 1 as the vertical direction of the pump motor. Note that the definition of the vertical direction does not limit the direction when the pump motor is used. Further, in this document, an end view parallel to the axial direction is referred to as a “vertical end view”. Further, “parallel” used in this document does not represent parallel in a strict sense, but includes substantially parallel. *

<1. Overall Configuration of Pump Motor> The overall configuration of the pump motor according to an exemplary embodiment of the present invention will be described. FIG. 1 is a vertical end view of a cutting part of a pump motor according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of the pump motor according to the embodiment of the present invention. In FIG. 2, drawing of the rotor is omitted. *

The pump motor 1 shown in FIGS. 1 and 2 includes a rotor 2, a stator 3, an upper bearing 11, a lower bearing 12, an upper bracket 13, a lower bracket 14, a thrust bearing 15, and a case member 16. And a resin portion 17. *

Note that a lubricant is interposed in the gap between the rotor 2 and the stator 3. This lubricant is water, for example, but may contain a preservative such as propylene glycol. *

The rotor 2 has a cylindrical shape extending in the axial direction. The rotor 2 is arranged with a predetermined gap on the radially inner side of the stator 3. The rotor 2 includes a rotating shaft 21, a rotor core 22, a magnet 23, a base member 24, a rotor can 25, a cover member 26, and a resin portion 27. *

The rotating shaft 21 is a rotating shaft of the pump motor 1. The rotating shaft 21 has a cylindrical shape extending in the axial direction (vertical direction). The rotating shaft 21 is inserted into the upper bearing 11 and the lower bearing 12 and is rotatably supported. The upper bearing 11 is held by the upper bracket 13. The lower bearing 12 is held by the lower bracket 14. The rotor 2 rotates around a rotating shaft 21 extending in the axial direction (vertical direction). *

The rotor core 22 has a cylindrical shape extending in the axial direction. The rotating shaft 21 is inserted into the central portion of the rotor core 22 in the radial direction. The rotor core 22 is configured by, for example, laminating a plurality of magnetic steel plates in the axial direction. The magnet 23 is disposed on the radially outer side of the rotor core 22. A plurality of magnets 23 are arranged side by side at predetermined angular intervals in the circumferential direction. The magnet 23 is supported by the rotor core 22. *

The base member 24 is disposed at the lower part of the rotor 2 in the axial direction (vertical direction). The base member 24 has an annular shape. The rotating shaft 21 is inserted into the central portion of the base member 24 in the radial direction. The base member 24 supports the rotor core 22 and the magnet 23 at the lower portion in the axial direction of the rotor 2. The base member 24 constitutes a thrust bearing 15 with the lower bracket 14. *

The rotor can 25 is disposed on the outer peripheral side of the rotor 2. The rotor can 25 has a cylindrical shape extending in the axial direction. The rotor can 25 is supported by the base member 24 at the lower part in the axial direction. The rotor can 25 is supported by an annular cover member 26 at the upper part in the axial direction. The rotor can 25 is arranged with a predetermined interval between the inner peripheral surface thereof and the outer peripheral surface of the magnet 23. *

The resin part 27 is provided inside the rotor can 25. The resin portion 27 is surrounded by the inner peripheral surface of the rotor can 25, the outer peripheral surface of the rotating shaft 21, the end surface on the upper side in the axial direction of the base member 24, the end surface on the lower side in the axial direction of the cover member 26, and the outer surfaces of the rotor core 22 and magnet 23. Synthetic resin is poured into the space. *

The stator 3 has a cylindrical shape extending in the axial direction. The stator 3 is arranged with a predetermined gap on the radially inner side of the rotor 2. The stator 3 is held by the upper bracket 13 and the lower bracket 14. The stator 3 is disposed inside a cylindrical case member 16 that is an exterior of the pump motor 1. The resin portion 17 is provided by pouring synthetic resin into a space surrounded by the inner peripheral surface of the case member 16, the outer surface of the stator 3, the outer surface on the lower side in the axial direction of the upper bracket 13, and the outer surface on the upper side in the axial direction of the lower bracket 14. It is done. *

The stator 3 includes a stator core 31, an insulator 32, a coil 33, and a stator can 40. *

The stator core 31 has a cylindrical shape extending in the axial direction. The stator core 31 is formed by laminating a plurality of magnetic steel plates in the axial direction. The stator core 31 includes a core back 31a and teeth 31b (see FIG. 4). The core back 31a has an annular shape. The teeth 31b extend radially inward from the inner peripheral surface of the core back 31a. A plurality of teeth 31b are provided side by side at predetermined angular intervals in the circumferential direction. *

The insulator 32 is provided so as to surround the outer surface of the tooth 31b. The insulator 32 is disposed between the stator core 31 and the coil 33. The insulator 32 is not particularly limited in material, but is made of, for example, an electrically insulating member made of synthetic resin. The coil 33 is formed by winding an electric wire around the outer periphery of the insulator 32. *

The stator can 40 is disposed on the inner peripheral side of the stator 3. The stator can 40 has a cylindrical shape that surrounds the rotor 2 and extends in the axial direction. The stator can 40 is held by the upper bracket 13 at the upper part in the axial direction. The stator can 40 is held by the lower bracket 14 at the lower part in the axial direction. *

<2. Detailed Configuration of Stator Can> Next, a detailed configuration of the stator can 40 will be described. FIG. 3 is an external perspective view of the stator can 40 of the pump motor 1 according to the embodiment of the present invention. FIG. 4 is a partially enlarged plan view of the pump motor 1 according to the embodiment of the present invention. FIG. 5 is a partially enlarged external perspective view of the stator can 40 of the pump motor 1 according to the embodiment of the present invention. FIG. 6 is a partially enlarged cross-sectional perspective view of the pump motor 1 according to the embodiment of the present invention. FIG. 7 is a vertical end view of a partially enlarged cut portion of the pump motor 1 according to the embodiment of the present invention. FIG. 8 is a partially enlarged external perspective view of the stator can 40 of the pump motor 1 according to the embodiment of the present invention. *

The stator can 40 includes a rib 41, a protrusion 42, a flange 43, an outer groove 44, and an inner groove 45. The stator can 40 is not specifically limited in material, but is formed by, for example, pressing a metal member. *

The rib 41 shown in FIG. 3 protrudes radially outward from the outer peripheral surface of the stator can 40. The rib 41 extends linearly in the axial direction. A plurality of ribs 41 are arranged side by side at a predetermined angular interval in the circumferential direction, and each of them extends in parallel with the axial direction. By providing the rib 41 on the stator can 40, the strength of the stator can 40 is improved. Therefore, even when a high pressure is generated in the gap between the rotor 2 and the stator 3, the pump can be operated stably. *

Moreover, since the rib 41 protrudes radially outward from the outer peripheral surface of the stator can 40, contact between the rotor 2 and the stator 3 can be avoided. Furthermore, since the lubricant (water) flows smoothly with the rotation of the rotor 2 in the gap between the rotor 2 and the stator 3, it is possible to obtain a suitable rotational performance of the rotor 2. *

The rib 41 extends continuously from one end to the other end of the stator can 40 in the axial direction. That is, the rib 41 continuously extends from the upper end to the lower end in the axial direction of the stator can 40. According to this configuration, the strength of the stator can 40 can be further increased as compared with the case where the ribs extend intermittently in the axial direction. Furthermore, since the rib 41 can be molded using a simple axial upper and lower mold, the productivity of the pump motor 1 can be improved. *

The rib 41 is connected to the stator can 40. That is, the rib 41 is provided integrally with the stator can 40. According to this configuration, the strength of the stator can 40 can be further increased as compared with the case where the rib is provided as a separate part with respect to the stator can 40. Further, the rib 41 can be formed together with the stator can 40. Thereby, the number of parts and assembly man-hours of the pump motor 1 can be reduced, and the cost can be reduced. *

A plurality of ribs 41 are provided side by side at predetermined angular intervals in the circumferential direction. For example, the same number of the ribs 41 as the teeth 31b of the stator core 31 are provided. For example, when there are nine teeth 31b, there are nine ribs 41. And the rib 41 shown in FIG. 4 is arrange | positioned 1 each between the teeth 31b adjacent to the circumferential direction. According to this configuration, the stator can 40 and the stator core 31 can be brought close to each other. Thereby, it is possible to reduce the size of the pump motor 1.

In addition, the rib 41 arrange | positioned between the teeth 31b adjacent to the circumferential direction is not necessarily limited to one like this embodiment. You may arrange | position the some rib 41 between the teeth 31b adjacent to the circumferential direction. *

The protrusion 42 is provided at the lower portion of the stator can 40 in the axial direction (vertical direction). The protrusion 42 protrudes radially outward from the outer peripheral surface of the stator can 40. The protrusion 42 extends linearly in the axial direction from the lower end of the stator can 40 in the axial direction with a predetermined length that does not reach the central portion of the stator can 40 in the axial direction. The protrusion 42 shown in FIG. 5 has an upper surface 42a facing the upper side in the axial direction at the end on the upper side in the axial direction. A plurality of protrusions 42 are arranged side by side at a predetermined angular interval in the circumferential direction, and each of the protrusions 42 extends parallel to the axial direction. *

6 is in contact with the insulator 32 in the axial direction on the upper surface 42a. According to this configuration, the relative position between the stator can 40 and the insulator 32 in the axial direction is determined. As a result, the stator can 40 can be positioned in the stator 3. *

The flange portion 43 is provided at the lower end in the axial direction (vertical direction) of the stator can 40. The flange portion 43 has a disk shape extending radially outward from the inner peripheral side of the stator can 40. The protrusion 42 is provided on the upper side in the axial direction than the flange 43. *

The outer groove 44 is provided on the outer circumferential surface on the radially outer side of the flange portion 43. The outer groove 44 is recessed from the outer peripheral surface of the flange portion 43 of the stator can 40 toward the radially inner side. The outer groove 44 is continuous in the circumferential direction and is annular. *

An O-ring 18 is attached to the outer groove 44. The O-ring 18 is a rubber seal material, for example. The flange portion 43 of the stator can 40 is inserted inside the lower bracket 14 in the radial direction. The O-ring 18 is compressed in the radial direction between the flange portion 43 and the lower bracket 14 and is in close contact with the flange portion 43 and the lower bracket 14. Since the O-ring 18 can be disposed in the outer groove 44 in this way, when the flange portion 43 is inserted into the lower bracket 14, the lubricant is applied to the region where the stator core 31 is provided in the region of the O-ring 18. It is possible to prevent leakage. *

The inner groove 45 shown in FIGS. 7 and 8 is provided in the upper part of the stator can 40 in the axial direction (vertical direction). The inner groove 45 is recessed from the inner peripheral surface of the stator can 40 toward the radially outer side. The inner groove 45 is continuous in the circumferential direction and has an annular shape. *

The upper bracket 13 is provided with an O-ring 19 on the radially outer side of the lower portion thereof. The O-ring 19 is, for example, a rubber seal material. The lower portion of the upper bracket 13 is inserted inside the stator can 40 in the radial direction. At this time, a part on the outer side in the radial direction of the O-ring 19 enters the inner groove 45. The O-ring 19 is compressed in the radial direction between the upper bracket 13 and the stator can 40 and is in close contact with the upper bracket 13 and the stator can 40. Since the O-ring 19 can be disposed in the inner groove 45 in this way, when the upper bracket 13 is inserted into the stator can 40, the lubricant is applied to the region where the stator core 31 is provided in the region of the O-ring 19. It is possible to prevent leakage. *

<3. First Modification of Pump Motor According to Embodiment> Next, a first modification of the pump motor 1 according to the embodiment will be described. FIG. 9 is a cross-sectional perspective view of a first modification of the pump motor according to the embodiment of the present invention. *

In the first modification of the pump motor 1 according to the embodiment, the rib 41 protrudes radially inward from the inner peripheral surface of the stator can 40. The rib 41 extends linearly in the axial direction. A plurality of ribs 41 are arranged at predetermined angular intervals in the circumferential direction and extend parallel to the axial direction. *

Even when the rib 41 is provided on the inner peripheral surface of the stator can 40, the strength of the stator can 40 is improved. Therefore, even when a high pressure is generated in the gap between the rotor 2 and the stator 3, the pump can be operated stably. *

<4. Second Modification of Pump Motor of Embodiment> Next, a second modification of the pump motor 1 of the embodiment will be described. FIG. 10 is an external perspective view of a stator can of a second modification of the pump motor according to the embodiment of the present invention. *

In the second modification of the pump motor 1 of the embodiment, the rib 41 protrudes radially inward from the inner peripheral surface of the stator can 40. The rib 41 extends linearly in the axial direction. A plurality of ribs 41 are arranged at predetermined angular intervals in the circumferential direction and extend parallel to the axial direction. The rib 41 extends intermittently from one end of the stator can 40 in the axial direction to the other end. *

Even when the rib 41 is provided so as to extend intermittently in the axial direction of the stator can 40, the strength of the stator can 40 is improved. Therefore, even when a high pressure is generated in the gap between the rotor 2 and the stator 3, the pump can be operated stably. *

Note that the location where each of the plurality of ribs 41 is interrupted in the axial direction may be the same location in the axial direction as shown in FIG. *

<5. Others> Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. Moreover, the said embodiment and its modification can be combined arbitrarily arbitrarily. *

For example, in addition to the rib 41 extending in the axial direction, a circumferential rib extending in the circumferential direction may be provided in combination on the circumferential surface of the stator can 40.

The present invention can be used in, for example, a pump motor.

DESCRIPTION OF SYMBOLS 1 ... Pump motor, 2 ... Rotor, 3 ... Stator, 11 ... Upper bearing, 12 ... Lower bearing, 13 ... Upper bracket, 14 ... Lower bracket, 15. .... Thrust bearing, 16 ... Case member, 17 ... Resin part, 18, 19 ... O-ring, 21 ... Rotating shaft, 22 ... Rotor core, 23 ... Magnet, 24 ... -Base member, 25 ... rotor can, 26 ... cover member, 27 ... resin part, 31 ... stator core, 31a ... core back, 31b ... teeth, 32 ... insulator, 33 ... Coil, 40 ... Stator can, 41 ... Rib, 42 ... Projection, 42a ... Upper surface, 43 ... Flange, 44 ... Outer groove, 45 ... Inside groove

Claims

A rotor that rotates about a rotation axis extending in the vertical direction;
A stator disposed radially outside the rotor;
A cylindrical stator can that is arranged on the inner peripheral side of the stator and surrounds the rotor and extends in the axial direction;
Have
The stator can has a rib protruding in a radial direction from a peripheral surface and extending in an axial direction.
2. The pump motor according to claim 1, wherein the rib extends continuously from one end to the other end in the axial direction of the stator can.
3. The pump motor according to claim 1, wherein the rib protrudes radially outward from an outer peripheral surface of the stator can.
4. The pump motor according to claim 1, wherein the rib is connected to the stator can.
The stator has a stator core;
The stator core is
An annular core back,
A plurality of teeth extending radially inward from the inner peripheral surface of the core back;
With
The pump motor according to any one of claims 1 to 4, wherein the rib is disposed between the teeth adjacent in the circumferential direction.
The stator includes a coil and an insulator around which the coil is wound.
The stator can has a protrusion protruding radially outward from the outer peripheral surface of the stator can,
The pump motor according to any one of claims 1 to 5, wherein the protrusion is in contact with the insulator in an axial direction.
The stator can is recessed radially outward from the inner peripheral surface of the stator can,
The pump motor according to any one of claims 1 to 6, further comprising an inner groove continuous in the circumferential direction.
The stator can is recessed from the outer peripheral surface of the stator can toward the radially inner side,
The pump motor according to any one of claims 1 to 7, further comprising an outer groove continuous in a circumferential direction.