JP2025092999A - Electric pump - Google Patents

Abstract

To reduce an axial dimension of an electric pump by eliminating the necessity of a rotor shaft of a rotor.SOLUTION: An electric pump uses an axial gap motor. A rotor includes an internal gear type outer rotor 430 and an external gear type inner rotor 450. The outer rotor 430 is accommodated in a rotor accommodation chamber while located coaxially with a stator and being not displaceable in the radial direction. The inner rotor 450 is accommodated in an internal gear space of the outer rotor 430 while being not displaceable in the radial direction and eccentric to a central axis of the outer rotor 430, and partially engages with the internal gear 434 of the outer rotor 430. A space Sp is formed between the internal gear 434 of the outer rotor 430 and the external gear 453 of the inner rotor 450. Integral rotation of the outer rotor 430, the inner rotor 450 and the space Sp constitutes a pump part in the rotor accommodation chamber.SELECTED DRAWING: Figure 9

Description

This technology relates to an electric pump that uses an axial gap motor in which the stator and rotor are arranged axially opposite each other.

The technology related to the electric pump described above is described in Patent Document 1. As shown in Figs. 11 and 12, the electric pump 100 described in Patent Document 1 is composed of a pump section 110 and a motor section 120. The pump section 110 has a substantially cylindrical pump chamber 113 formed in the center of a housing 112, a suction port 114 communicating with the pump chamber 113, and a discharge port 115. A disk-shaped rotor 122 is housed in the pump chamber 113 in a state where it is eccentric with respect to the pump chamber 113 and can rotate around a rotor shaft 123. The rotor 122 is a part that constitutes the rotor of the motor section 120 (axial gap motor), and is magnetized with two poles, an N pole and an S pole, in each semicircle, as shown in Fig. 11.

On the outer periphery of the rotor 122, vane grooves (figures omitted) are formed at the 0° position and the 180° position, and the vanes 124 are mounted in the vane grooves so that they can protrude radially outward by magnetic force and can be stored in the vane grooves by receiving a radially inward pressing force. In addition, the stator 126 of the motor section 120 is attached coaxially with the rotor 122 on the lower side of the housing 112 of the pump section 110. That is, the stator 126 of the motor section 120 and the rotor 122 are connected to each other coaxially by the rotor shaft 123. The stator 126 is composed of three coils 127 that generate a magnetic field, a back yoke 128, and an electric circuit section 129 that energizes the coils 127 in a predetermined order. As a result, the rotor 122 rotates around the rotor shaft 123 due to the action of the magnetic flux generated by the coils 127 and the permanent magnet of the rotor 122, and the electric pump 100 is driven.

JP 2007-51611 A

The rotor 122 constituting the pump section 110 of the electric pump 100 and the stator 126 of the motor section 120 are connected coaxially by the rotor shaft 123. For this reason, as shown in FIG. 12, the stator 126 of the motor section 120 requires a bearing section that rotatably supports the rotor shaft 123. Therefore, even if the axial (vertical) dimensions of the electric pump 100 are reduced by using an axial gap motor, there is a limit to how much the dimensions of the electric pump 100 can be reduced in the axial direction because the bearing section of the rotor shaft 123 is located on the stator 126 side.

This technology was developed to solve the above problems, and the problem that the present invention aims to solve is to eliminate the need for a bearing part for the rotor shaft on the stator side of the motor unit, thereby reducing the axial dimensions of the electric pump.

The above problems are solved by each technology. The first technology is an electric pump using an axial gap motor in which a stator and a rotor are arranged axially opposite to each other, and the rotor is provided with an internal gear type outer rotor and an external gear type inner rotor, the outer rotor is accommodated in a rotor accommodation chamber coaxially with the stator and unable to be displaced radially, the inner rotor is accommodated in the internal gear space of the outer rotor in a state where it cannot be displaced radially and is eccentric with respect to the central axis of the outer rotor, and is partially meshed with the internal gear of the outer rotor, a space is formed between the internal gear of the outer rotor and the external gear of the inner rotor, and the outer rotor, the inner rotor, and the space rotate together to form a pump section in the rotor accommodation chamber.

According to the above technology, the outer rotor constituting the rotor of the axial gap motor is accommodated in the rotor accommodation chamber in a state where it is coaxial with the stator and cannot be displaced in the radial direction. In other words, by accommodating the outer rotor in the rotor accommodation chamber, a rotor shaft for holding the outer rotor coaxially with the stator is not required as in the conventional technology. In addition, the inner rotor constituting the rotor is accommodated in the internal gear space of the outer rotor in a state where it cannot be displaced radially outward and is eccentric with respect to the central axis of the outer rotor, and is partially meshed with the internal gear of the outer rotor. Therefore, the inner rotor cannot rotate relative to the outer rotor and rotates integrally with the outer rotor. In this way, there is no need to provide a bearing portion for the rotor shaft on the stator side of the axial gap motor, so the axial dimensions of the electric pump can be reduced.

According to the second technology, the stator includes a fixed side magnetic body consisting of a fixed side ring portion and a plurality of salient pole portions arranged at equal intervals in the circumferential direction of the fixed side ring portion, a coil wound around each salient pole portion of the fixed side magnetic body, and a controller capable of switching the current supply to the plurality of coils in a predetermined order, and the outer rotor of the rotor includes a ring portion arranged coaxially with the fixed side ring portion of the stator, a rotating side magnetic body consisting of a plurality of salient pole portions arranged at equal intervals in the circumferential direction of the ring portion and facing the salient pole portions of the stator, and a conductor that covers the ring portion while surrounding the plurality of salient pole portions of the rotating side magnetic body, and the conductor is formed concentric with the rotating side magnetic body and has a diameter larger than the rotating side magnetic body by a certain dimension.

According to the above technology, the magnetic flux generated in the stator coil passes from the salient pole portion of the fixed magnetic body of the stator to the salient pole portion of the rotating magnetic body of the outer rotor. This causes eddy currents to flow in the conductor of the outer rotor so as to surround the salient pole portion of the rotating magnetic body. As a result, a force is generated between the magnetic flux and the eddy currents in a direction that rotates the outer rotor. Here, the conductor of the outer rotor is concentric with the rotating magnetic body and is formed with a diameter larger than the rotating magnetic body by a certain dimension. This makes it easier for eddy currents to flow around the salient pole portion of the rotating magnetic body.

According to the third technology, a cooling opening is formed in the wall portion that closes the axial end of the internal gear space of the outer rotor, which guides a portion of the fluid in the space formed between the internal gear of the outer rotor and the external gear of the inner rotor to the position of the controller. This makes it possible to cool the controller by the fluid guided from the cooling opening to the position of the controller.

According to the fourth technology, the housing that constitutes the rotor chamber is formed with an intake hole that supplies fluid into the rotor chamber and a discharge hole that discharges the fluid from the rotor chamber, and the opening area of the intake hole and the discharge hole is set to be 10 times or more the opening area of the cooling opening formed in the outer rotor. Therefore, even if a fluid is used to cool the controller, the pump performance is not significantly affected.

The electric pump according to the fifth technology is configured to pump a fluid capable of cooling the drive motor of an electric vehicle.

The technology of this application eliminates the need for a bearing portion for the rotor shaft on the stator side, allowing the axial dimensions of an electric pump using an axial gap motor to be reduced.

1 is a schematic vertical sectional view of an electric pump using an axial gap motor according to a first embodiment of the present invention; FIG. 2 is a plan view of a stator and a housing of the axial gap motor (viewed along the arrows II-II in FIG. 1 ). 3 is a plan cross-sectional view (view taken along the line III-III in FIG. 1 ) illustrating a coil and the like of a stator of the axial gap motor. FIG. 4 is a plan view (view taken along the line IV-IV in FIG. 1 ) of a rotor (outer rotor) and a housing of the axial gap motor. FIG. 2 is a plan cross-sectional view of an outer rotor and an inner rotor of the axial gap motor (viewed along the V-V arrows in FIG. 1 ). FIG. 6 is a cross-sectional plan view of an outer rotor and an inner rotor of the axial gap motor (viewed along the arrows VI-VI in FIG. 1 ). FIG. 2 is a schematic longitudinal sectional view showing a magnetic circuit between a stator and a rotor of the axial gap motor. 4 is a schematic cross-sectional plan view showing eddy currents generated in a rotor (outer rotor) of the axial gap motor. FIG. 3 is a cross-sectional plan view showing the operation of a pump portion of the electric pump. FIG. FIG. 11 is a cross-sectional plan view of an electric pump using an axial gap motor according to a first modified example. FIG. 1 is a perspective view of an electric pump using a conventional axial gap motor. FIG. 1 is a vertical sectional view of an electric pump using a conventional axial gap motor.

[Embodiment 1]
An electric pump according to a first embodiment of the present invention will be described below with reference to Figures 1 to 10. The electric pump 10 according to this embodiment is a pump that uses an axial gap motor, and pumps oil for lubrication and cooling to the drive motor of an electric vehicle. Here, front, back, left, right, and up and down in the figures correspond to front, back, left, right, and up and down of the electric pump 10.

<Overview of electric pump 10>
1, the electric pump 10 is a pump that uses an axial gap motor in which a stator 30 and a rotor 40 are arranged facing each other in the axial direction (up and down direction), and the rotor 40 forms a pump section (trochoid pump) within a housing 20. The electric pump 10 includes a cylindrical container-shaped housing 20, a stator 30 housed coaxially in the upper half of the housing 20, a rotor 40 housed coaxially in the lower half of the housing 20, and a controller 50 housed in an upper central opening of the stator 30.

<Regarding the housing 20>
As shown in Fig. 1, the housing 20 is composed of a cylindrical housing body 22 with a bottom and a disk-shaped cover 24 that closes the upper opening of the housing body 22. A ring-shaped inner flange 22f is formed on the inner wall surface of the housing body 22 at a position a certain distance below the upper opening. The inner flange 22f of the housing body 22 supports the periphery of the stator 30 of the axial gap motor from below. The rotor 40 of the axial gap motor is accommodated below the inner flange 22f of the housing body 22. That is, the lower side of the inner flange 22f of the housing body 22 becomes a rotor accommodating chamber 22h that accommodates the rotor 40.

As shown in FIG. 4 and other figures, the inner diameter of the rotor accommodating chamber 22h of the housing body 22 is set to a value larger than the outer diameter of the rotor 40 (outer rotor 430) by the amount of clearance. That is, the outer rotor 430 of the rotor 40 is constrained from the radially outer side by the inner wall surface of the rotor accommodating chamber 22h of the housing body 22. Therefore, the outer rotor 430 cannot be displaced in the radial direction even if there is no central axis of rotation, and can rotate around the axis in a state where it is coaxial with the stator 30.

1, the bottom plate 22b of the housing body 22 is provided with an intake hole 25 for supplying oil to the pump section (described later) composed of the rotor accommodating chamber 22h and the rotor 40 (outer rotor 430, inner rotor 450) and a discharge hole 26 for discharging oil. As shown in FIG. 4, the intake hole 25 is formed in an arc shape surrounding the center at the front side of the center of the bottom plate 22b of the housing body 22. The discharge hole 26 is also formed in an arc shape surrounding the center at the rear side of the center of the bottom plate 22b of the housing body 22. Furthermore, the bottom plate 22b of the housing body 22 is provided with a bearing hole (not shown) for supporting the lower end of the rotation center axis J of the inner rotor 450. At the rear of the lid 24 that closes the upper opening of the housing body 22, a connector 24c for supplying power to the controller 50 is provided so as to protrude upward as shown in FIG. 1. The housing 20 is formed of, for example, a resin such as plastic.

<Regarding the stator 30>
As shown in Figs. 1 to 3, the stator 30 includes a fixed magnetic body 310 formed by laminating thin electromagnetic steel plates in the axial direction, and a plurality of coils 35 (six in the figures). The fixed magnetic body 310 includes a ring-shaped fixed ring portion 312 and a plurality of salient pole portions 314 (six in the figures) that protrude from the lower surface of the fixed ring portion 312 in the axial direction and are provided at equal intervals in the circumferential direction of the fixed ring portion 312. As shown in Fig. 3, the coil 35 is wound around each salient pole portion 314 of the fixed magnetic body 310. As shown in Fig. 1, the periphery of the fixed ring portion 312 of the fixed magnetic body 310 of the stator 30 is placed on the inner flange portion 22f of the housing main body 22. The salient pole portions 314 and the coils 35 of the stator 30 pass through the opening of the inner flange portion 22f of the housing main body 22 and protrude downward. Here, instead of forming the fixed magnetic body 310 by laminating electromagnetic steel sheets, it is also possible to form the fixed magnetic body 310 using a powder magnetic core.

<Regarding the controller 50>
As shown in Fig. 1, the controller 50 is housed in the circular opening 316 of the fixed-side ring portion 312 of the fixed-side magnetic body 310 of the stator 30 while being covered by a disk-shaped cover member 54. As shown in Fig. 3, the controller 50 is configured to energize the U-phase coil 35, the V-phase coil 35, and the W-phase coil 35, which are used as a pair, in a predetermined order. In the electric pump 10 according to this embodiment, the U-phase and V-phase coils 35 in Fig. 3 are first energized, then the V-phase and W-phase coils 35 are energized, and then the W-phase and U-phase coils 35 are energized, and this energization order is repeated. As a result, the magnetic flux generated in the coils 35 rotates counterclockwise at a constant speed.

As shown in FIG. 1, the controller 50 is provided in the center of a disk-shaped electric circuit board 52, and the periphery of the electric circuit board 52 is placed on the fixed side ring portion 312 of the fixed side magnetic body 310 of the stator 30. The conductive portion of the electric circuit board 52 is connected to the connector 24c of the housing 20. In addition, the cover member 54 that covers the controller 50 is made of a material with high heat dissipation performance.

<Regarding the rotor 40>
As shown in Fig. 1, Fig. 5, etc., the rotor 40 is composed of an outer rotor 430 and an inner rotor 450. Note that the housing body 22 is omitted from Fig. 5, etc. The outer rotor 430 includes a rotating magnetic body 437 formed by laminating thin electromagnetic steel plates in the axial direction, and a rotor body 431 which is an aluminum alloy conductor that covers and supports the rotating magnetic body 437. As described above, the rotor body 431 of the outer rotor 430 is held in a state in which it can rotate around the axis within the rotor accommodating chamber 22h of the housing body 22 (see Figs. 1 and 4).

<Regarding the rotor body portion 431 of the outer rotor 430>
1, a cylindrical vertical wall portion 432 is provided on the outer peripheral edge of the rotor body portion 431 of the outer rotor 430. The cylindrical vertical wall portion 432 is fitted between the inner flange portion 22f and the bottom plate 22b of the housing body portion 22 and prevents the outer rotor 430 from moving in the axial direction. A magnetic body support portion 433 is formed in a ring shape on the radially inner side of the cylindrical vertical wall portion 432 of the rotor body portion 431, as shown in FIG.

In addition, as shown in FIG. 5 and the like, the rotor body 431 of the outer rotor 430 has an internal gear 434 formed radially inside the magnetic body support portion 433. The internal gear 434 has seven tooth grooves 434m formed at equal intervals in the circumferential direction with which the external gear 453 of the inner rotor 450 (described later) can mesh. That is, a cylindrical internal gear space S is formed by the internal gear 434 in the center of the rotor body 431. As shown in FIG. 1 and FIG. 4, the rotor body 431 has a ceiling wall portion 435 that closes the upper opening of the internal gear space S formed by the internal gear 434. The ceiling wall portion 435 of the rotor body 431 has a pair of cooling openings 435a, 435b that communicate the internal gear space S of the rotor body 431 with the housing inner space Su near the controller 50.

<Regarding the Rotating Side Magnetic Body 437 of the Outer Rotor 430>
4 to 6 and 7, the rotation-side magnetic body 437 of the outer rotor 430 is composed of a ring portion 438 and a plurality of salient pole portions 439 (eight in the figure) that protrude in the axial direction from the upper surface of the ring portion 438 and are provided at equal intervals in the circumferential direction of the ring portion 438. The rotation-side magnetic body 437 is embedded in the magnetic body support portion 433 of the rotor main body portion 431, which is an electric conductor from the ring portion 438 to the vicinity of the tip of the salient pole portion 439 (see FIG. 1, etc.).

Therefore, as shown in the schematic development diagram of FIG. 7, the magnetic flux φ (white arrow in FIG. 7) generated in the coil 35 of the stator 30 passes through a magnetic circuit consisting of the fixed side magnetic body 310 of the stator 30 and the rotating side magnetic body 437 of the outer rotor 430. As a result, as shown in FIG. 8, eddy current I flows around the salient pole portion 439 of the rotating side magnetic body 437 of the outer rotor 430 (the rotor body portion 431 which is a conductor). As a result, an electromagnetic force is generated between the magnetic flux φ and the eddy current I, and the outer rotor 430 rotates in the rotation direction of the magnetic flux φ generated in the coil 35 of the stator 30. Here, since the rotor body portion 431 of the outer rotor 430 is formed with a larger diameter than the ring portion 438 of the rotating side magnetic body 437, the eddy current I easily flows around the salient pole portion 439 of the rotating side magnetic body 437. It is also possible to configure the rotating side magnetic body 437 using a powder magnetic core instead of configuring it using an electromagnetic steel plate.

<Regarding the inner rotor 450>
As shown in Fig. 5 and other figures, the inner rotor 450 is an external gear type rotor that constitutes a trochoid pump together with the internal gear 434 of the outer rotor 430. The external gear 453 of the inner rotor 450 has six external teeth 453t equally spaced in the circumferential direction. The axial length dimension (height dimension in Fig. 1) of the external gear 453 is set to a value equal to the axial length dimension of the internal gear 434 of the outer rotor 430. As a result, the inner rotor 450 is sandwiched and restrained from the top and bottom directions (axial direction) by the ceiling wall portion 435 of the outer rotor 430 and the bottom plate 22b of the housing main body portion 22 as shown in Fig. 1.

Three consecutive external teeth 453t (the upper external teeth 453t in FIG. 5) of the external gear 453 of the inner rotor 450 mesh with three tooth grooves 434m of the internal gear 434 of the outer rotor 430. And, of the three external teeth 453t of the external gear 453, the tip of the external tooth 453t (the lower end external tooth 453t) located on the opposite side of the center from the central external tooth 453t abuts the inner circumferential surface of the internal gear 434.

As a result, the inner rotor 450 is housed in the internal gear space S of the outer rotor 430 in an eccentric state relative to the outer rotor 430, and is constrained from the radial outside. That is, the center C1 of the inner rotor 450 is eccentric from the central axis C0 of the outer rotor 430. The inner rotor 450 is also held so that it cannot rotate relative to the outer rotor 430 in the circumferential direction. That is, the inner rotor 450 rotates integrally with the outer rotor 430. The position of the center C1 of the inner rotor 450 is rotatably supported by the above-mentioned rotation center axis J, and is connected to the bottom plate 22b of the housing main body 22 (see Figures 1 and 5).

Furthermore, a pump space Sp is formed between the external gear 453 of the inner rotor 450 and the internal gear 434 of the outer rotor 430. As shown in FIG. 9, when the outer rotor 430 and the inner rotor 450 rotate left (see white arrow), the pump space Sp can move on the bottom plate 22b of the housing body 22 along the arc-shaped suction hole 25 and discharge hole 26 formed in the bottom plate 22b. As a result, the fluid (oil) sucked into the pump space Sp from the suction hole 25 is discharged from the pump space Sp to the outside through the discharge hole 26. Here, the opening area of the suction hole 25 and discharge hole 26 formed in the bottom plate 22b of the housing body 22 is set to be 10 times or more the opening area of the cooling openings 435a, 435b formed in the ceiling wall portion 435 of the outer rotor 430.

<Operation of electric pump 10>
When power is supplied to the controller 50 of the electric pump 10 via the connector 24c of the housing 20, the controller 50 energizes the coils 35 of the stator 30 in a predetermined order. That is, first, the coils 35 of the U and V phases are energized, then the coils 35 of the V and W phases are energized, and then the coils 35 of the W and U phases are energized, and this energization is repeated. As a result, the magnetic flux φ generated in the coils 35 rotates counterclockwise at a constant speed.

When the magnetic flux φ is passed through the magnetic circuit consisting of the fixed magnetic body 310 of the stator 30 and the rotating magnetic body 437 of the outer rotor 430, the magnetic flux φ causes an eddy current I to flow in the rotor body 431 of the outer rotor 430. As a result, an electromagnetic force is generated between the magnetic flux φ and the eddy current I, and the outer rotor 430 rotates in the direction of the magnetic flux φ generated in the coil 35 of the stator 30 (rotates counterclockwise).

9, the outer rotor 430, the inner rotor 450, and the pump space Sp rotate counterclockwise as one unit, and the pump space Sp moves along the arc-shaped suction hole 25 and discharge hole 26 formed in the bottom plate 22b of the housing body 22. As a result, the fluid (oil) sucked into the pump space Sp from the suction hole 25 is discharged from the pump space Sp to the outside through the discharge hole 26. Here, when the fluid is sucked into the pump space Sp from the suction hole 25, the fluid in the housing inner space Su near the controller 50 is sucked through the cooling opening 435a of the ceiling wall 435. Also, when the fluid is discharged from the discharge hole 26, the fluid is discharged into the housing inner space Su near the controller 50 through the cooling opening 435b of the ceiling wall 435. As a result, the controller 50 is cooled by the fluid.

<Correspondence of terms between the electric pump 10 according to this embodiment and the electric pump according to the present invention>
The rotor body 431 of the outer rotor 430 in the electric pump 10 according to this embodiment corresponds to the conductor of the outer rotor in the present invention. The pump space Sp corresponds to the space formed between the internal gear of the outer rotor and the external gear of the inner rotor. Furthermore, the ceiling wall 435 of the rotor body 431 corresponds to the wall closing the axial end of the internal gear space of the outer rotor in the present invention.

Advantages of the electric pump 10 according to this embodiment
According to the electric pump 10 of this embodiment, the outer rotor 430 constituting the rotor 40 of the axial gap motor is accommodated in the rotor accommodation chamber 22h in a state where it is coaxial with the stator 30 and cannot be displaced in the radial direction. That is, by accommodating the outer rotor 430 in the rotor accommodation chamber 22h, a rotor shaft for holding the outer rotor 430 coaxially with the stator 30 is not required as in the conventional case. In addition, the inner rotor 450 constituting the rotor 40 is accommodated in the internal gear space S of the outer rotor 430 in a state where it cannot be displaced radially outward and is eccentric with respect to the central axis C0 of the outer rotor 430, and is partially meshed with the internal gear 434 of the outer rotor 430. Therefore, the inner rotor 450 cannot rotate relative to the outer rotor 430 and rotates integrally with the outer rotor 430. In this way, since it is not necessary to provide a bearing portion for the rotor shaft on the stator 30 side of the axial gap motor, the size of the electric pump 10 in the axial direction can be reduced.

In addition, the rotor body 431 (conductor) of the outer rotor 430 is formed with a larger diameter than the ring portion 438 of the rotating magnetic body 437, so that eddy current I easily flows around the salient pole portion 439 of the rotating magnetic body 437. Furthermore, the opening area of the intake hole 25 and the discharge hole 26 formed in the bottom plate 22b of the housing body 22 is set to be 10 times or more the opening area of the cooling openings 435a, 435b formed in the ceiling wall portion 435 of the outer rotor 430. Therefore, even if a fluid is used to cool the controller 50, the pump performance of the electric pump 10 is not significantly affected.

<Example of change>
Here, the present invention is not limited to the above embodiment, and modifications are possible within the scope of the present invention. For example, in the present embodiment, an induction motor type axial gap motor in which the outer rotor 430 is composed of a rotor body 431 made of a conductor and a rotating side magnetic body 437 made of an electromagnetic steel plate is exemplified. However, as shown in FIG. 10, it is also possible to use a brushless motor type axial gap motor in which the outer rotor 430 is composed of a rotor body 431 made of an insulating material and a multi-pole permanent magnet 60.

<Other changes>
In addition, in this embodiment, an axial gap motor consisting of a stator 30 having six coils 35 and an outer rotor 430 having eight salient pole portions 439 has been exemplified, but the number of coils in the stator 30 and the number of salient pole portions in the outer rotor 430 can be changed as appropriate.

10... Electric pump 20... Housing 22... Housing main body 22h... Rotor accommodating chamber 22b... Bottom plate 25... Intake hole 26... Discharge hole 30... Stator 310... Fixed side magnetic body 312... Fixed side ring portion 314... Salient pole portion 35... Coil 40... Rotor 430... Outer rotor 431... Rotor main body (conductor)
434m...tooth groove 434...internal gear 435...ceiling wall portion (wall portion closing the axial end of the internal gear space)
435a: Cooling opening 435b: Cooling opening 437: Rotating magnetic body 438: Ring portion 439: Salient pole portion 450: Inner rotor 453t: External teeth 453: External gear 50: Controller 52: Electric circuit board S: Internal gear space Sp: Pump space (space)

Claims (5)

An electric pump using an axial gap motor in which a stator and a rotor are arranged opposite to each other in the axial direction,
The rotor includes an internal gear type outer rotor and an external gear type inner rotor,
The outer rotor is accommodated in a rotor accommodating chamber so as to be coaxial with the stator and unable to be displaced in a radial direction,
the inner rotor is accommodated in an internal gear space of the outer rotor in a state in which the inner rotor cannot be displaced in a radial direction and is eccentric with respect to a central axis of the outer rotor, and is partially meshed with the internal gear of the outer rotor;
A space is formed between the internal gear of the outer rotor and the external gear of the inner rotor,
The electric pump in which the outer rotor, the inner rotor, and the space rotate together to form a pump portion within the rotor accommodating chamber. 2. The electric pump according to claim 1,
the stator includes a fixed-side magnetic body including a fixed-side ring portion and a plurality of salient pole portions provided at equal intervals in the circumferential direction of the fixed-side ring portion, a coil wound around each of the salient pole portions of the fixed-side magnetic body, and a controller capable of switching energization of the coils in a predetermined order;
the outer rotor of the rotor includes a ring portion provided coaxially with the fixed-side ring portion of the stator, a rotating-side magnetic body including a plurality of salient pole portions provided at equal intervals in the circumferential direction of the ring portion and facing the salient pole portions of the stator, and a conductor covering the ring portion while surrounding the plurality of salient pole portions of the rotating-side magnetic body;
The electric conductor is concentric with the rotating magnetic body and has a diameter larger than that of the rotating magnetic body by a certain dimension. The electric pump according to claim 1 or 2,
An electric pump in which a cooling opening is formed in a wall portion sealing the axial end of the internal gear space of the outer rotor, the cooling opening directing a portion of the fluid in the space formed between the internal gear of the outer rotor and the external gear of the inner rotor to the position of the controller. 4. The electric pump according to claim 3,
A housing constituting the rotor accommodating chamber is formed with a suction hole for supplying fluid into the rotor accommodating chamber and a discharge hole for discharging the fluid in the rotor accommodating chamber,
an electric pump in which the opening area of the suction hole and the discharge hole is set to be 10 times or more the opening area of the cooling opening formed in the outer rotor. 2. The electric pump according to claim 1,
An electric pump configured to pump a fluid capable of cooling a drive motor of an electric vehicle.

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