WO2015186163A1

WO2015186163A1 - Axial gap motor

Info

Publication number: WO2015186163A1
Application number: PCT/JP2014/064570
Authority: WO
Inventors: 芳紹堤; 見多出口; 明仁中原; 孝仁村木
Original assignee: 株式会社日立製作所
Priority date: 2014-06-02
Filing date: 2014-06-02
Publication date: 2015-12-10

Abstract

Provided is an axial gap motor structure in which a cooling medium is appropriately supplied to a place to be cooled in a stator. An axial gap motor has a rotor fixed to a rotating shaft, a stator disposed facing the rotor in a shaft direction, and a cooling medium supply pipe for supplying a cooling medium to the stator, wherein the cooling medium supply pipe is disposed adjacent to the stator in a radial direction and a first windshield wall is disposed between the rotor and the stator in a shaft direction.

Description

Axial gap motor

The present invention relates to an axial gap motor.

¡Axial gap motor is composed of a disk-shaped rotor and a stator placed facing it. The rotor has a plurality of flat permanent magnets arranged in the circumferential direction, and the stator has a plurality of electromagnets composed of a core and a coil arranged in the circumferential direction. The rotor is attached to the shaft. The shaft is supported by a bearing attached to the end bracket. The stator is held by the housing on the outer peripheral side. The housing is coupled to the end bracket. In the case of a fully-closed axial gap motor, the housing and the end bracket cover all directions.

In an axial gap motor, for example, in order to increase the torque per physique, a two-rotor / one-stator configuration in which both sides of the stator are sandwiched by two rotors and a gap surface is formed on both sides of the stator is performed.

多く Most of the loss in the axial gap motor occurs in the coils and cores that make up the electromagnet. The loss is converted into heat and transferred to the core, the core support member, and the housing in contact with the core by heat conduction, and is finally radiated to the outside air. As an alternative path, heat is transferred from the stator to the rotor by heat transfer of the internal gas. The heat transferred to the rotor and the shaft is transferred to the bearing and the end bracket by heat conduction, and a part of the heat is transferred to the housing by heat transfer and finally radiated to the outside air. The temperature of the stator and the rotor rises due to the heat that has not been dissipated. When the magnet temperature of the rotor increases, the magnetic force decreases, and the efficiency of the axial gap motor decreases.

For example, when the axial gap motor is mounted on a hybrid vehicle, a large torque is required. As the torque increases, the current flowing through the coil increases, and the heat generated in the coil and core increases. Therefore, the axial gap motor cannot be sufficiently cooled only by radiating the heat from the housing to the surrounding air by conventional heat conduction and cooling it.

Therefore, it is necessary to supply the cooling medium directly to the stator to promote cooling by utilizing the heat transfer of the cooling medium and to suppress this temperature rise. However, when the axial gap motor rotates, an air flow of several tens of m / s is generated depending on the rotational speed of the rotor and the diameter of the rotor. Simply by supplying the cooling refrigerant, the cooling medium supplied by the air flow is scattered and cannot be supplied to a desired place to be cooled.

As a device using a cooling medium for cooling the stator of an axial type rotating electric machine, there is one shown in Patent Document 1, and the coil and the core are cooled by circulating the cooling medium with a closed structure of the coil.

Japanese Patent Application Laid-Open No. 2005-261083

In Patent Document 1, the coil and the core are sealed, and cooling is performed by flowing a cooling medium in the sealed space. In this cooling method, since the cooling medium is supplied only to the coil and the core, the core support member, the shaft and the like to which the cooling medium is not supplied are not cooled.

The present invention provides an axial gap motor structure in which a cooling medium is appropriately supplied to a place where the stator is to be cooled.

The features of the present invention for solving the above problems are as follows, for example.

An axial gap motor having a rotor fixed to a rotating shaft, a stator arranged to face the rotor in the axial direction, and a cooling medium supply pipe for supplying a cooling medium to the stator, in the radial direction of the stator An axial gap motor in which a cooling medium supply pipe is disposed adjacently and a first windbreak wall is disposed between the rotor and the stator in the axial direction.

According to the present invention, the cooling medium is appropriately supplied to the place where the stator is to be cooled. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

Sectional drawing explaining an example of the axial gap motor of this invention A perspective view of a cooling medium supply pipe for supplying a cooling medium for the upper half of the stator Perspective view of upper second windbreak wall for upper half of stator A perspective view of a cooling medium supply pipe for supplying a cooling medium for the lower half of the stator Perspective view of the lower second windbreak for the lower half of the stator Detailed view of the vicinity of the upper coolant supply pipe Sectional drawing of the axial gap motor in another embodiment of this invention Sectional drawing of the axial gap motor in another embodiment of this invention Detailed view of the vicinity of the cooling medium supply pipe in another embodiment of the present invention Bird's eye view of the first windbreak and stator Bird's-eye view of stator with first windbreak removed

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.

The first embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view illustrating an example of an axial gap motor of the present invention. FIG. 2 is a perspective view of a cooling medium supply pipe for supplying a cooling medium for the upper half of the stator. FIG. 3 is a perspective view of the upper second windbreak wall for the upper half of the stator. FIG. 4 is a perspective view of a cooling medium supply pipe for supplying a cooling medium for the lower half of the stator. FIG. 5 is a perspective view of the lower second windbreak wall for the lower half of the stator. FIG. 6 is a detailed view of the vicinity of the upper cooling medium supply pipe.

The axial gap motor according to an embodiment of the present invention can be applied to a hybrid vehicle or an electric vehicle, but is not limited thereto. It is desirable to apply the axial gap motor according to an embodiment of the present invention to a hybrid vehicle that requires a large torque.

The axial gap motor 1 according to the present invention includes a disk-shaped rotor 3 fixed to a rotating shaft, a stator 2 disposed opposite to the rotor 3 in the axial direction via a gap, and the rotor 3 on the inner periphery of the rotor 3. It is composed of a connected shaft 4 (rotating shaft), a bearing 5 that supports the shaft 4, an end bracket 62 to which the bearing 5 is attached, and a housing 61 connected to the outer periphery of the end bracket 62 and the stator 2. ing. The housing 6 includes a cylindrical housing 61 that covers the stator 2 and the rotor 3, and end plates 62 that are attached to both ends of the housing 61.

The rotor 3 is composed of a magnet, a structural material for holding the magnet, a back yoke, and the like (not shown). As the magnet of the rotor 3, a ferrite magnet or a neodymium magnet is used.

The stator 2 includes a core 22, a coil 21 wound around the core 22, and a support member 23 that supports the core 22. The coil 21 of the stator 2 uses a copper wire or an aluminum wire. The core 22 is made of a laminated magnetic magnetic steel sheet or amorphous foil or a soft magnetic material such as a dust core.

In one embodiment of the present invention, as shown in FIG. 1, the upper cooling medium supply pipe 81 (cooling medium supply pipe 8) is disposed above the coil 21 in the upper half of the stator 2. Further, the lower cooling medium supply pipe 82 (cooling medium supply pipe 8) is disposed on the upper side of the coil 21 in the lower half of the stator 2. In other words, the cooling medium supply pipe 8 is disposed adjacent to the radial direction of the stator 2. The upper second windbreak wall 72 is disposed in the axial direction and on the side near the rotor 3 on the side of the upper cooling medium supply pipe 81.

The first windbreak wall 71 is disposed between the rotor 3 and the stator 2 in the axial direction. The first windbreak wall 71 forms a flow path through which the cooling medium flows from one end in the radial direction of the stator 2 toward the other end. The first windbreak wall 71 is made of heat-resistant resin, and is disposed so as to cover the entire surface of the rotor 3 side between the adjacent cores 22 in a concentric disk shape.

A cooling medium discharge port 9 for collecting the cooling medium is provided at the lower portion of the housing 61.

As shown in FIG. 2, the upper half cooling medium supply pipe 81 for the upper half has a cooling pipe of the same diameter on the concave surface of the hollow cooling medium supply pipe 81 having an arc shape with an outer diameter R2 and an inner diameter R1 and a circular cross section. A plurality of medium supply holes 83 are opened at substantially equal intervals. The angle of the arc of the upper cooling medium supply pipe 81 (indicated by θ in the figure) is approximately 180 degrees or more so that the cooling medium supply hole 83 can be provided also in the lateral direction (side direction in the figure) in FIG. It is preferable that the angle is.

The upper second windbreak wall 72 has a structure that covers the side surface on the rotor 3 side of the upper cooling medium supply pipe 81 of FIG. 2 as shown in FIG.

The lower cooling medium supply pipe 82 for the lower half is the same as the convex surface of the lower cooling medium supply pipe 82 of the hollow pipe having the outer diameter R2, the inner diameter R1, and the circular arc shape as shown in FIG. A plurality of cooling medium supply holes 83 having a diameter are opened at substantially equal intervals. The angle of the arc of the lower cooling medium supply pipe 82 (denoted by θ in the figure) is approximately 180 degrees so that the cooling medium supply hole 83 can also be provided in the lateral direction (side direction in the figure) in FIG. The above angle is preferable.

The lower second windbreak wall 73 has a structure that covers the rotor 3 side surface of the lower cooling medium supply pipe 82 of FIG. 4 as shown in FIG.

Details of the vicinity of the upper cooling medium supply pipe 81 are shown in FIG. The upper cooling medium supply pipe 81 is provided on the upper side in the outer diameter direction of the coil 21, and the cooling medium supply hole 83 opens downward in the upper cooling medium supply pipe 81. A first windbreak wall 71 is provided between the stator 2 and the rotor 3, and a second windbreak wall 72 is provided on the rotor 3 side of the upper cooling medium supply pipe 81. A flow of the cooling medium ejected from the cooling medium supply hole 83 is indicated by 100. In the vicinity of the lower cooling medium supply pipe 82, the positional relationship is the same and only the structures of the lower cooling medium supply pipe 82 and the lower second windbreak wall 72 are different.

The operation of the axial gap motor 1 of this embodiment will be described. When the coil 21 is energized using an inverter or AC power supply not shown in the figure, an alternating magnetic field is formed on the surface of the stator 2. The alternating magnetic field and the static magnetic field of the rotor 3 by the magnet are attracted and repelled, whereby the rotor 3 generates rotor torque. The cooling medium is supplied from a cooling medium supply pipe 8 from a cooling medium supply system (not shown) installed outside the axial gap motor 1. The cooling medium supplied to the cooling medium supply pipe 8 is ejected from the cooling medium supply hole 83 and is also supplied to the support member 23 by the coil 21 and the core 22 of the stator 2 and the flow.

In the upper half of the axial gap motor 1, the cooling medium ejected from the upper refrigerant supply pipe 81 is not affected by the air current generated by the rotation of the rotor 3 by the upper second windbreak wall 72, and the desired coil 21 and core 22 desired. Reach the place. Further, the cooling medium flowing between the portion of the stator 2 facing the rotor 3, that is, between the slots of the core 22, is not affected by the airflow generated by the rotor 3, and the coil 21, the core 22, or the core support It is supplied to the member 23 and cooled. Thereafter, a part of the supplied cooling medium is dropped on the shaft 4 to cool the shaft 4. Further, the cooling medium is transported to another part of the stator 2 by the centrifugal force generated by the rotation of the shaft 4, and the other part of the stator 2 is cooled. Another part of the cooling medium is supplied to the other part of the stator 2 through the coil 21 and cools the other part of the stator 2.

In the lower half of the axial gap motor 1, the cooling medium ejected from the lower refrigerant supply pipe 82 is not affected by the air flow generated by the rotation of the rotor 3 by the lower second windbreak wall 73, and the coil 21 and the core 22. To reach the desired location. Further, the cooling medium flowing through the portion of the stator 2 facing the rotor 3, that is, the slot between the adjacent cores 22, by the first windbreak wall 71 is not affected by the air flow generated by the rotor 3, and is not affected by the coil 21, the core 22 or the core. It is supplied to the support member 23 and cooled. In addition to this, in the lower half of the axial gap motor 1, the cooling medium flowing from the upper half is also supplied, contributing to cooling of the lower half of the stator 2.

The cooling medium that has cooled the stator 2 reaches the inner wall of the housing 61, flows, and is discharged from the cooling medium discharge port 9 provided at the lower portion of the housing 61 to the outside of the casing 6 of the axial gap motor 1. The cooling medium discharged from the axial gap motor 1 returns to the cooling medium supply system, and is supplied again to the axial gap motor 1 from the cooling medium supply pipe 8 to perform cooling.

In the present embodiment, the cooling medium supply pipes 8 are provided on both sides of the stator 2. That is, the rotor 3 is configured by a first rotor and a second rotor that are arranged to face each other in the axial direction with the stator 2 interposed therebetween. The stator 2 includes a core 22 and a support member 23 that supports the core 22. The first coil disposed on the side of the support member 23 on the side close to the first rotor with respect to the axial direction and the side of the support member 23 on the side close to the second rotor with respect to the axial direction. The cooling medium supply pipe is configured by the second coil, and the cooling medium supply pipe is disposed on the radially outer side of the first coil, and the lower cooling medium supply is disposed on the radially inner side of the second coil. And a tube 82. If the cooling medium is to be supplied to both surfaces of the stator 2 by using one cooling medium supply pipe 8 without doing so, in order to obtain a spread for supplying the cooling medium to an appropriate place of the coil 21, This is because the distance from 2 becomes longer and the outer diameter of the axial gap motor 1 increases significantly.

In one embodiment of the present invention, since the sealing structure in which the cooling medium is allowed to flow through the coil and the core as in Patent Document 1 is not formed, after the flow path is formed, the confirmation of the sealing structure of the flow path and problems occur. In this case, it is not necessary to repair the sealed structure of the flow path, and the productivity is improved.

In this embodiment, the cross-sectional shapes of the upper cooling medium supply pipe 81 and the lower cooling medium supply pipe 82 do not necessarily have to be circular, and may be closed so that the cooling medium can be transported. In addition, the diameters of the cooling medium supply holes 83 are the same and are substantially equally spaced. Since the pressure decreases from the supply side of the cooling medium supply pipe 8 toward the downstream side, the following operation is performed from the upstream side of the cooling medium supply pipe 8 toward the downstream side. The cooling medium can be ejected evenly. The method is to gradually increase the diameter of the cooling medium supply holes 83 toward the downstream, or to arrange the cooling medium supply holes 83 of the same diameter at appropriate intervals that are not equal.

In the present embodiment, the first windbreak wall 71, the upper second windbreak wall 72, and the lower second windbreak wall 73 are separate and provided with a gap. In other words, the upper second windbreak wall 72 is disposed so as to provide a gap between the end portion of the upper second windbreak wall 72 and the end portion of the first windbreak wall 71, and the lower second windbreak wall 73 is arranged so as to provide a gap between the end portion of the lower second windbreak wall 73 and the end portion of the first windbreak wall 71, and a part of the rotor 3 is arranged in the gap. The temperature of the stator 2 portion to which the upper second windbreak wall 72 and the lower second windbreak wall 73 are attached is lower than the temperature of the core 22 portion to which the first windbreak wall 71 is attached. Different materials can be used. Therefore, it is not necessary to use the same material for all. The upper second windbreak wall 72 and the lower second windbreak wall 73 can be made of a material having a heat resistant temperature lower than that of the first windbreak wall 71. Thereby, cost can be reduced.

Further, the first windbreak wall 71 extends radially outward in the upper half and is integrated with the upper second windbreak wall 72, and is integrated with the lower second windbreak wall 73 in the lower half. An effect is obtained. The upper second windbreak wall 72 and the lower second windbreak wall 73 are fixed to the stator 2 at one end, but the upper second windbreak wall 72 and the lower second windbreak wall 73 are integrated with the first windbreak wall 71. Then, the support is supported at two locations by the stator 2 and the core 22. Therefore, since it is supported firmly, the plate | board thickness of the upper side 2nd windbreak wall 72 and the lower side 2nd windbreak wall 73 can be made thin. Thereby, cost can be reduced.

FIG. 7 is a cross-sectional view of an axial gap motor according to another embodiment of the present invention. In the present embodiment, the other configuration is the same as that of the first embodiment except that the lower cooling medium supply pipe 82 for the lower half of the stator 2 and the lower second windbreak wall 73 are not provided.

When the lower half of the shaft 4 is narrow and the lower cooling medium supply pipe 82 and the lower second windbreak wall 73 for the lower half cannot be provided, the cooling medium that flows through the cooling medium supply pipe 8 is omitted. Increase the amount of. In the present embodiment, the lower cooling refrigerant supply pipe 82 for the lower half of the stator 2 and the lower second windbreak wall 73 can be omitted, so that the structure of the stator 2 can be simplified as compared with the first embodiment.

FIG. 8 is a cross-sectional view of an axial gap motor according to another embodiment of the present invention. In this embodiment, instead of the lower cooling medium supply pipe 82 and the lower second windbreak wall 73 in the lower half of the stator 2, the upper cooling medium supply pipe 81 and the upper second windbreak wall 72 are arranged in the radial direction of the stator 2. Except for being provided outside, the other configuration is the same as that of the first embodiment. The same members as those in the first embodiment are given the same numbers.

If there is a restriction on the space near the lower half of the shaft 4, but there is no restriction on the space on the lower half of the housing 61, the upper cooling medium supply pipe 81 and the upper second windbreak wall 72 for the upper half are connected to the stator 2. It is provided on the outer peripheral side of the lower half. In this way, the cooling medium can be directly supplied to the lower half of the stator 2 as compared with the second embodiment. In the present embodiment, since the upper cooling medium supply pipe 81 and the upper second windbreak wall 72 for the upper half of the stator 2 can be used also on the lower side of the stator 2, productivity can be improved.

FIG. 9 is a detailed view of the vicinity of the coolant supply pipe according to another embodiment of the present invention. Other configurations are the same as those in the first embodiment except that the position of the cooling medium supply pipe 8 is different. The same members as those in the first embodiment are given the same numbers.

In the first embodiment, since the cooling medium supply hole 83 of the cooling medium supply pipe 8 is opened downward, the flow 100 of the jetted cooling medium is widened, and a distance that can supply an appropriate region to the coil 21 is necessary. . In this embodiment, the cooling medium supply hole 83 is provided so as to be inclined from below. Therefore, the distance that the flow 100 of the jetted cooling medium has an appropriate spread can be shortened compared to the case where the cooling medium supply hole 83 faces downward. As a result, an increase in the diameter of the axial gap motor 1 can be suppressed.

Another embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a bird's-eye view of the first windbreak wall and the stator. FIG. 11 is a bird's-eye view of the stator with the first windbreak wall 71 of FIG. 10 removed.

In FIG. 10, the upper coolant supply pipe 81 and the lower coolant supply pipe 82 of the coolant supply pipe 8 are omitted. In FIG. 10, the first windbreak wall 71 is arranged on the core 21 of the stator 2 so as to cover the entire rotor 3 side surface between the adjacent cores 22 and the rotor 22 side surface of the core 22 in a concentric disk shape. Yes.

In FIG. 11, the coil 21 is in contact with the side surface of one of the cores 22 in the slot a between the adjacent cores 22. By doing so, the cooling refrigerant supplied from the cooling refrigerant supply pipe 8 flows through the coil 21 without being obstructed when flowing through the slot a, and cooling with the cooling medium is performed efficiently. Further, since the coil 21 is in contact with the core 22 over a wide area, the heat generated in the coil 21 is more transferred to the core 22 and the support member 23 having a large heat capacity, so that the temperature of the coil 21 can be lowered.

DESCRIPTION OF SYMBOLS 1 ... Axial gap motor 2 ... Stator 3 ... Rotor 4 ... Shaft 5 ... Bearing 6 ... Housing 7 ... Windproof wall 8 ... Cooling medium supply pipe 9 ... Cooling medium discharge port 21 ... Coil 22 ... Core 23 ... Support member 61 ... Housing 62 ... End bracket 71 ... First windbreak wall 72 ... Upper second windbreak wall 73 ... Lower second windbreak wall 81 ... Upper cooling medium supply pipe 82 ... Lower cooling medium supply pipe 83 ... Cooling medium supply hole 100 ... ejected Coolant flow

Claims

A rotor fixed to the rotating shaft;
A stator arranged opposite to the rotor in the axial direction;
A cooling medium supply pipe for supplying a cooling medium to the stator, and an axial gap motor,
The cooling medium supply pipe is disposed adjacent to the radial direction of the stator,
An axial gap motor in which a first windbreak wall is disposed between the rotor and the stator in the axial direction.
In claim 1,
An axial gap motor provided with the 2nd windbreak wall arrange | positioned in the said axial direction and the side of the said cooling-medium supply pipe | tube near the said rotor.
In claim 2,
The second windbreak wall is disposed so as to provide a gap between an end portion of the second windbreak wall and an end portion of the first windbreak wall.
An axial gap motor in which a part of the rotor is disposed in the gap.
In claim 2,
The first windbreak wall is an axial gap motor formed integrally with the second windbreak wall.
In any one of Claims 1 thru | or 4,
The first windbreak wall is an axial gap motor that forms a flow path through which the cooling medium flows from one radial end to the other end of the stator.
In any one of Claims 1 thru | or 5,
The cooling medium supply pipe has a cooling medium supply hole;
An axial gap motor in which the cooling medium supply hole is inclined.
In any one of Claims 1 thru | or 6.
The stator is
The core,
A support member for supporting the core;
A coil disposed on the side of the support member on the side close to the rotor with respect to the axial direction, and
The axial gap motor is arranged such that the coil is in contact with a side surface of the core.
In any one of Claims 1 thru | or 7,
The rotor is composed of a first rotor and a second rotor that are arranged to face each other in the axial direction across the stator,
The stator is
The core,
A support member for supporting the core;
A first coil disposed on the side of the support member on the side closer to the first rotor with respect to the axial direction;
A second coil disposed on the side of the support member on the side close to the second rotor with respect to the axial direction, and
The supply pipe is
An upper cooling medium supply pipe disposed on a radially outer side of the first coil;
An axial gap motor comprising: a lower cooling medium supply pipe disposed on the radially inner side of the second coil.