JP2016163373A - Axial gap motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial gap motor which can keep a uniform temperature of a stator when directly supplying a cooling medium to the stator.SOLUTION: A shaft is horizontally disposed. A rotor is fixed to the shaft. A stator is arranged so as to face the rotor. A cooling medium supply pipe 8 is disposed around the stator, and includes a plurality of cooling medium supply holes 82 which discharge the cooling medium to the stator. The cooling medium supply pipe 8 discharges more cooling medium from a second portion which extends from its uppermost part along a rotating direction opposite to that of the rotor, than a first portion which extends from its uppermost part along the rotating direction of the rotor.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an axial gap motor.

  The axial gap motor is composed of a disk-shaped rotor and a stator placed facing the rotor. 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 the axial gap motor, in order to increase the torque per physique, both sides of the stator are sandwiched between two rotors, and a two-rotor one-stator configuration is formed in which gap surfaces are formed on both sides of the stator.

  Most of the loss in the axial gap motor is generated in the coil and core constituting the electromagnet. The loss becomes heat and is transmitted to the core and the core support member in contact with the core by heat conduction, and is finally radiated to the outside air. As another 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 increases 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.

  When the axial gap motor is mounted on a hybrid vehicle or an electric 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 transfer and cooling it.

  On the other hand, an axial gap motor using a cooling medium for cooling the stator is known (see, for example, Patent Document 1). In Patent Document 1, the coil and the core are cooled by circulating the cooling medium with a sealed structure.

Japanese Patent Application Laid-Open No. 2005-261083

  The cooling method of Patent Document 1 has the following problems. Since the coil and the core are hermetically sealed and the cooling medium is allowed to flow in the sealed space for cooling, the cooling medium is supplied only to the coil and the core. The core support member and the shaft that are not supplied with the cooling medium are not cooled. In addition, in order to achieve a sealed structure in which a cooling medium flows through the coil and the core, after the flow path is formed, if a check or a malfunction of the sealed structure of the flow path occurs, this repair is necessary and productivity is reduced.

  Therefore, the inventor of the present application studied supplying the cooling medium directly to the stator to promote cooling by using the heat transfer of the cooling medium and suppressing this temperature increase. Here, when the axial gap motor rotates, an air flow is generated by the rotation of the rotor. As a result, the present inventor has found that the supplied cooling medium is scattered by the airflow of the rotor and cannot be uniformly supplied to the desired place to be cooled simply by supplying the cooling refrigerant.

  That is, it has been found that when the cooling medium is directly supplied to the stator without using the hermetic structure, the distribution of the cooling medium supply amount of the coil is uneven, and thus the coil temperature may not be uniform. When the coil temperature is not uniform, the operating condition of the axial gap motor is restricted by the coil temperature that is higher than that when the coil temperature is uniform.

  An object of the present invention is to provide an axial gap motor that can make the temperature of the stator uniform when supplying a cooling medium directly to the stator.

  In order to achieve the above-described object, the present invention provides a horizontally disposed rotating shaft, a rotor fixed to the rotating shaft, a stator facing the rotor, a periphery of the stator, and a cooling medium. A supply pipe having a plurality of holes for discharging to the stator, the supply pipe extending from the uppermost portion along the rotational direction of the rotor, and the rotational direction of the rotor from the uppermost portion. A large amount of the cooling medium is discharged from the second portion extending along the rotation direction opposite to the surface.

  According to the present invention, when the cooling medium is directly supplied to the stator, the temperature of the stator coil can be made uniform. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is an exploded perspective view of an axial gap motor according to a first embodiment of the present invention. FIG. 2 is a perspective view of a cooling medium supply pipe provided on the end bracket shown in FIG. 1. It is a schematic diagram of the behavior on the stator of the cooling medium when not implementing this invention. It is a schematic diagram of supply amount distribution on the stator of the cooling medium when not implementing this invention. It is a schematic diagram of supply amount distribution on the stator of the cooling medium which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the change of the cooling medium supply hole which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the change of the pitch of the cooling medium supply hole which concerns on the 2nd Embodiment of this invention.

  Hereinafter, the configuration and operational effects of the axial gap motor according to the first to second embodiments of the present invention will be described with reference to the drawings. The following description shows specific contents of the present invention, and the present invention is not limited to these. Various changes and modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Is 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.

(First embodiment)
The axial gap motor according to the first embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of an axial gap motor 1 of the present embodiment. FIG. 2 is a perspective view of a cooling medium supply pipe provided on the end bracket. FIG. 3 is a schematic view of the behavior of the cooling medium on the stator when the present invention is not carried out. FIG. 4 is a schematic diagram of the distribution of the supply amount of the cooling medium on the stator when the present invention is not carried out. FIG. 5 is a schematic diagram of the supply amount distribution on the stator of the cooling medium according to the first embodiment of the present invention. FIG. 6 is a schematic view of a change in the cooling medium supply hole according to the first embodiment of the present invention. In addition, as shown in FIG. 1, FIG. 3, gravity shall act toward the substantially paper lower surface.

The axial gap motor 1 of FIG. 1 is called a 1 stator 2 rotor type. The rotor _{3 (3} 1, _{3 2)} includes a first rotor _{3 1} and the second rotor _{3 2} disposed to face in the axial direction across the stator 2, the constructed. The stator 2 includes a core 22, a support member 23 for supporting the core 22, a first coil 21a which is arranged in the axial direction on a side of the first rotor 3 ₁ near side of the support member 23, the axial direction a second coil 21b which is disposed on the side of the support member 23 of the second rotor 3 ₂ close to the side with respect to (not shown), the constructed.

Flow path portion is composed of a first flow path portion passing through the side portion of the first rotor 3 ₁ in the radial direction and a second flow passage portion which passes through the side of the second rotor 3 ₂ in the radial direction and. The discharge port is composed of a first discharge port and a second discharge port. The first outlet, connected to the first flow path portion, than the first rotor 3 ₁ in the axial direction is provided in the vicinity of the first coil 21a. The second outlet, connected to the second flow path section than the second rotor 3 ₂ in the axial direction is provided in the vicinity of the second coil 21b.

The axial gap motor 1 according to the present embodiment includes a disk-shaped rotor 3 (3 ₁ , 3 ₂ ), a stator 2 facing the rotor 3 (3 ₁ , 3 ₂ ), a shaft 4 connected to the rotor 3 on the inner periphery of the rotor 3, A bearing (not shown) for supporting the shaft 4, an end bracket 62 to which the bearing is attached, and a housing 61 connected to the outer periphery of the stator 2 and the end bracket 62 are configured. The housing 6 includes a cylindrical housing 61 that houses the stator 2 and the rotor 3 and holds the cooling refrigerant supply pipe 8 (FIG. 2), and end brackets 62 that are attached to both ends of the housing 61. .

  The rotor 3 includes a magnet (not shown) and a structural material or a back yoke for holding the magnet. The rotor 3 is fixed to the shaft 4 (rotating shaft). 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 stator 2 faces the rotor 3 along the axial direction. 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. As the magnet of the rotor 3, a ferrite magnet or a neodymium magnet is used. The shaft 4 (rotary axis) is arranged horizontally (perpendicular to the direction of gravity).

  In FIG. 1, a cooling medium supply pipe inlet 83 and a cooling medium supply pipe outlet 84 are provided on the output shaft side illustrated as the A surface (end surface perpendicular to the shaft) of the end bracket 62. Similarly, a cooling medium supply pipe inlet 83 and a cooling medium supply pipe outlet 84 are also provided on the non-illustrated B surface opposite to the output shaft side. In FIG. 1, the cooling medium supply pipe inlet 83 is on the right side and the cooling medium supply pipe outlet 84 is on the left side, but the opposite arrangement, that is, the cooling medium supply inlet 83 is on the left side and the cooling medium supply pipe outlet 84 is on the left side. There is no functional problem on the right side. The axial gap motor 1 can be appropriately selected depending on the mounting form. Although not shown, a cooling medium discharge port for collecting the cooling medium is provided in the lower portion of the housing 61.

  As shown in FIG. 2, the cooling medium supply pipe 8 is formed with a thickness obtained by subtracting the inner peripheral side bending R <b> 1 of the cooling medium supply pipe 8 from the outer peripheral side bending radius R <b> 2 of the cooling medium supply pipe 8. In addition, the cooling medium supply pipe 8 is formed in an arc shape with an angle θ of the arc of the cooling medium supply pipe around the rotation axis in the circumferential direction. O in FIG. 2 represents the arc center of bending of the cooling medium supply pipe 8. As an example, the cross section of the cooling medium supply pipe 8 has a trapezoidal shape. The cooling medium supply pipe 8 is a hollow pipe having a structure in which a plurality of cooling medium supply holes 82 are opened on the inclined surface 81 of the cooling medium supply pipe 8. The angle of the arc of the cooling medium supply pipe 8 (indicated by Θ in FIG. 2) is approximately 180 ° or more in order to allow the cooling medium supply hole 82 to be provided also in the horizontal direction (side direction in the figure) in FIG. It is preferable that the angle is.

In FIG. 2, the diameter of the coolant supply hole 82 is d _h, the pitch of the adjacent cooling medium supply hole 82 is theta _p. Details of these will be described later with reference to FIGS. 5 and 6.

  Operation | movement of the axial gap motor 1 of this embodiment is demonstrated. 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.

  Next, the behavior of the cooling medium supplied from the cooling medium supply pipe 8 of the cooling medium supply 8 will be described with reference to FIG. FIG. 3 shows the coil 21 of the stator 2 from the side opposite to the output side shown as B surface in FIG. 1, and the flow of the cooling medium is schematically shown by black arrows. As described above, the angle is given to the zenith of the axial gap motor 0 ° counterclockwise.

  Hereinafter, the behavior of the cooling medium when a uniform refrigerant supply amount is supplied from the cooling medium supply hole 82 of the cooling medium supply pipe 8 will be described with reference to FIG. A cooling medium is supplied from a cooling medium supply system (not shown) installed outside the axial gap motor 1 from a cooling medium supply pipe inlet 83 connected to the cooling medium supply pipe 8. The cooling medium supplied to the cooling medium supply pipe 8 is ejected (discharged) from the cooling refrigerant supply hole 82 and supplied to the outer diameter side coil end 211 on the outer diameter side of the upper half coil 21 of the stator 2.

  Thereafter, the supplied cooling medium flows over the coil 21 (coil 212 between the cores) between the core 22 and the adjacent core 22, the core 22, and the support member 23 to perform cooling. After that, it flows through the inner diameter side coil end 213 on the inner diameter side of the upper half coil 21 and is scattered by the rotating shaft 4. The cooling medium scattered by the shaft 4 is concentrated in the vicinity of the point C, which is approximately 90 ° forward of the rotational direction from the position where the cooling medium is dropped. The remaining dripped cooling medium slides on the surface of the rotating shaft 4 and is intensively scattered in the vicinity of the point D, which is about 90 ° behind the rotation direction from the dripped position.

  The cooling medium scattered in the vicinity of the point C travels through the inner diameter side coil end 213 on the lower half side and flows to the other inner diameter coil end 213. The cooling medium that has flowed to the inner diameter coil end 213 flows through the lower half-slot coil 212, the lower half core 22, and the support member 23, and flows around the outer periphery of the stator 2 toward 180 ° (lowermost part). The cooling medium at point D behaves similarly to the cooling medium at point C.

  The distribution of the supply amount of the cooling medium at this time is shown in FIG. The vertical axis in FIG. 4 is the relative supply amount of the cooling medium, and the horizontal axis is the angle given in the same manner as in FIG. The amount of the cooling medium supplied to the lower half of the coil 21 increases from 90 ° to 180 °. On the other hand, the amount of the cooling medium decreases from 180 ° to 270 °. Therefore, a large temperature distribution bias is generated on the lower half side of the coil 21.

  On the other hand, the scattering of the cooling medium to the lower half of the stator 2 by the rotating shaft 4 as described above is considered. Specifically, instead of supplying the cooling medium uniformly from the cooling medium supply hole 82 of the cooling medium supply pipe 8, the reverse bias is preliminarily taken into consideration that a difference in supply amount due to the rotation of the shaft occurs. The case where it is supplied is described below. In this embodiment, as shown in FIG. 3, the rotor rotates counterclockwise toward the paper surface, and the supply direction of the cooling medium rotates clockwise so as to face this, that is, from 90 ° to 0 ° and 270 °. It shall be supplied.

  Therefore, the supply amount of the cooling medium from 90 ° to 0 ° is made smaller than the supply amount of the cooling medium from 270 ° to 0 °. By doing so, the amount of the cooling medium scattered forward by the rotation of the shaft 4 and supplied to the point C decreases, and the amount of the cooling medium supplied to the point D increases by sliding the remaining surface of the shaft 4. As a result, the amount of the cooling medium supplied to the lower half coil 21 is substantially uniform as shown in FIG. 5, and the temperature of the lower half coil 21 is uniform. In this case, a little distribution occurs in the cooling medium supply amount to the coil 21 on the upper half side, but the distribution is much smaller than the distribution of the cooling medium supply amount on the lower half side when this distribution is not given. The temperature distribution generated in the coil 21 is small and does not cause a problem.

Intervals in order to achieve the above is how the coolant supply hole 82 that is, changing the diameter d _h of the cooling medium supply hole 82 as shown in FIG. 6 by the pitch theta _p constant. The vertical axis in FIG. 6 is the diameter of the cooling medium supply hole, and the horizontal axis is the angle given as in FIG. Relatively large diameter d _h2 of the second half of the hole relative to the diameter d _h1 of the first half of the supply direction of the cooling medium supply hole 82, made to be d _h1 <d _h2. Here, the cooling refrigerant supply hole 82 has only from 0 ° to 90 ° and from 270 ° to 360 °, as described in the explanation of FIG. This is because the refrigerant supply hole 82 is set to 180 degrees in θ. The same applies to the following description.

  That is, the cooling medium supply pipe 8 is disposed on the radially outer side and the vertically upper side of the stator. The cooling medium supply pipe 8 has an arc shape, and the plurality of cooling medium supply holes 82 have a vertical upward direction of 0 ° and a rotational direction of the rotor 3 of 0 to 90 ° when the rotation direction is a positive angle. It is arranged in a range and a range of 270 to 360 °.

  On the other hand, when the supply direction of the cooling medium and the rotation direction of the rotor 3 are the same, the first half of the supply direction is increased. Also in this case, the distribution of the cooling medium relative supply amount with respect to the angle applied in the same manner as in FIG. 3 is the same as in FIG. In this case, since the cooling medium is supplied from 270 ° to 0 ° and 90 °, the relative supply amount of the cooling medium increases in the first half, that is, 270 ° to 0 °.

  The amount of the cooling medium supplied to the lower half side coil 2 in the same way even when the rotation of the rotor is not counterclockwise toward the paper surface as shown in FIG. Can be made uniform.

  As described above, the cooling medium supply pipe 8 is disposed around the stator 2 and has a plurality of cooling medium supply holes 82 for discharging the cooling medium to the stator 2. The cooling medium supply pipe 8 has more from the second portion extending from the uppermost portion along the rotation direction opposite to the rotation direction of the rotor 3 than the first portion extending from the uppermost portion along the rotation direction of the rotor 3. Discharge the cooling medium.

In the present embodiment, the diameter d _h2 of the plurality of holes in the second portion is larger than the diameter d _h1 of the plurality of holes in the first portion. In other words, the sum of the opening areas of the plurality of holes in the second portion is larger than the sum of the opening areas of the plurality of holes in the first portion.

  Here, the cooling medium ejected from the cooling refrigerant supply pipe 8 flows through the upper half side coil, core and support member. Thereafter, the cooling medium is dropped on the rotating shaft to cool the shaft and then scattered. The scattered cooling medium cools the lower half coil 21, core 22 and support member 23. Considering that a difference in supply amount due to the rotation of the shaft 4 occurs in the amount of cooling medium supplied from the upper half side of the stator 2, a reverse bias is given in advance and the cooling medium amount is supplied uniformly by the rotation of the shaft. . Therefore, the distribution of the supply amount of the cooling medium is uniform on the lower half side of the stator 2, and the stator 2 including the coil 21, the core 22, and the support member 23 can be cooled uniformly.

  As described above, according to the present embodiment, when the cooling medium is directly supplied to the stator, the temperature of the stator can be made uniform.

(Second Embodiment)
Also in this embodiment, the rotation direction of the rotor 3 is set to the left rotation toward the paper surface of FIG. 3, and the supply direction of the cooling medium is set to the right rotation toward the paper surface facing the same. In consideration of the occurrence of a difference in supply amount due to the rotation of the shaft 4, in order to supply with a reverse bias in advance, the cooling medium supply hole 82 has a constant diameter d _h and is cooled as shown in FIG. The pitch θ _p of the medium supply holes 82 is changed. The vertical axis in FIG. 7 is the pitch of the cooling medium supply holes, and the horizontal axis is the angle given as in FIG. The pitch θ _p2 of the second half hole is relatively small with respect to the first half pitch θ _{p1 in} the supply direction of the cooling medium supply hole 82 so that θ _p1 > θ _p2 . In this way, in the first half of the supply of the cooling medium, the number of the cooling medium supply holes 82 is smaller than that in the second half, and a large amount of the cooling medium is supplied to the upper half coil 2 in the second half.

  On the other hand, when the cooling medium supply direction and the rotor rotation direction are the same, the first half of the supply direction is increased. In this case as well, the distribution of the cooling medium relative supply amount with respect to the given angle is the same as in FIG.

Thus, the pitch θ _p2 of the plurality of cooling medium supply holes 82 in the second portion is smaller than the pitch θ _p1 of the plurality of cooling medium supply holes 82 in the first portion. In other words, the sum of the opening areas of the plurality of holes in the second portion is larger than the sum of the opening areas of the plurality of holes in the first portion.

  In the present embodiment, in the processing of the cooling medium supply hole 82, it is only necessary to perform the processing with the same drill or the like and change the pitch, so that the productivity is improved. That is, the number of processing steps can be reduced.

  As described above, according to the present embodiment, when the cooling medium is directly supplied to the stator, the temperature of the stator can be made uniform. In addition, productivity is improved.

It should be noted that both the first embodiment and the second embodiment, that is, adjusting both the pitch θ _p of the cooling medium supply holes 82 and the diameter d _h of the cooling medium supply holes 82, The supply amount is increased in the second half of the supply direction when the cooling medium supply direction and the rotor rotation direction are opposite to each other, and when the cooling medium supply direction and the rotor rotation direction are the same, the first half of the supply direction is increased. Can be increased.

  The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  In the above embodiment, the axial gap motor is a 2-rotor 1-stator type, but may be a 1-rotor 1-stator type, a 1-rotor 2-stator type, or the like.

DESCRIPTION OF SYMBOLS 1 ... Axial gap motor 2 ... Stator 3 ... Rotor 4 ... Shaft 6 ... Housing 8 ... Coolant supply pipe 21 ... Coil 21a ... First coil 21b ... Second coil 22 ... Core 23 ... Support member 61 ... Housing 62 ... End Bracket 81 ... inclined surface 82 of cooling refrigerant supply pipe ... cooling medium supply hole 83 ... cooling refrigerant supply pipe inlet 84 ... cooling refrigerant supply pipe outlet 211 ... outer diameter side coil end 212 ... coil between slots (coil between cores)
213 ... inner diameter side coil end O ... arc center R1 ... inner circumferential side bend radius R2 ... outer circumferential side bend radius d h _... coolant supply holes of the cooling medium supply pipe 8 for coolant supply pipe 8 for bending the coolant supply pipe 8 Diameter Θ ... Cooling medium supply pipe arc angle θ _p ... Cooling medium supply hole pitch

Claims (8)

A rotating shaft arranged horizontally;
A rotor fixed to the rotating shaft;
A stator facing the rotor;
A supply pipe disposed around the stator and having a plurality of holes for discharging a cooling medium to the stator;
The supply pipe is
More cooling medium is discharged from the second portion extending from the uppermost portion along the rotation direction opposite to the rotation direction of the rotor than the first portion extending from the uppermost portion along the rotation direction of the rotor. Axial gap motor characterized by The axial gap motor according to claim 1,
The diameter of the plurality of holes in the second part is
An axial gap motor characterized by being larger in diameter than the plurality of holes in the first portion. The axial gap motor according to claim 1,
The pitch of the plurality of holes in the second part is
The axial gap motor is smaller than the pitch of the plurality of holes in the first portion. The axial gap motor according to claim 1,
The supply pipe is
An axial gap motor, wherein the axial gap motor is disposed radially outside and vertically above the stator. The axial gap motor according to claim 1,
The supply pipe is
Arcuate,
The plurality of holes are:
An axial gap motor, wherein the axial gap motor is arranged in a range of 0 to 90 ° and a range of 270 to 360 ° when the vertical upward direction is 0 ° and the rotation direction of the rotor is a positive angle. The axial gap motor according to claim 1,
The cooling medium is
The axial gap motor characterized by flowing in the supply pipe in a rotation direction opposite to the rotation direction of the rotor. The axial gap motor according to claim 1,
The cooling medium is
An axial gap motor characterized by flowing in the supply pipe in the same direction as the rotation direction of the rotor. The axial gap motor according to claim 1,
The sum total of the opening areas of the plurality of holes in the second portion is:
The axial gap motor, wherein the axial gap motor is larger than a sum of opening areas of the plurality of holes in the first portion.

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