JP2013021759A - Rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary machine which efficiently cools coils densely wound without forming gaps.SOLUTION: A rotary machine includes: a rotor rotating around a rotation shaft; and a stator 30 disposed around the rotor. The stator 30 includes a stator core 31 having multiple teeth 31b formed so as to be arranged along the rotation direction of the rotor and coils 32 wound around the respective teeth 31b. Each of cross section shapes of the teeth 31b has a shape where at least one of a clearance C1, formed between each tooth and the coil 32, and a clearance, formed between the coils 32 wound around the adjacent teeth, is provided.

Description

  The present invention relates to a rotating machine such as an electric motor or a generator.

  As is well known, a rotating machine such as an electric motor or a generator includes a stator (stator) and a rotor (rotor), and converts the rotational kinetic energy of the rotor into electrical energy, or the electrical energy is rotated by the rotor. A device that converts kinetic energy. An electric motor provided in a vehicle such as a hybrid vehicle (HV) or an electric vehicle (EV) is used not only as a power generation source for generating power for running the vehicle but also for effective use of energy. It is also used as a generator (regenerative brake) that recovers kinetic energy of the vehicle as electric energy.

  The above-described rotating machine provided in a vehicle such as a hybrid vehicle or an electric vehicle is required to be miniaturized in order to reduce a vehicle-mounted space and to have a high output in order to improve traveling performance. As the power density increases in this way, the amount of heat generated by the rotating machine increases, so a cooling technique for efficiently cooling the rotating machine becomes important. The following Patent Documents 1 and 2 disclose techniques for increasing the cooling efficiency of a coil provided in a stator of a rotating machine.

  Specifically, in Patent Document 1 below, an insulating resin is formed on the surface of the tooth portion other than the corner portion by forming a step at the corner portion of the tooth portion provided in the stator core and molding the insulating resin. A technique for improving the cooling efficiency by reducing the thickness of the pipe is disclosed. Further, in Patent Document 2 below, the side surface of the tooth along the rotation axis direction is a convex surface that becomes a middle height in the rotation axis direction so that the teeth of the annular stator core and the coil are in contact with each other without any gap in the rotation axis direction of the motor. Discloses a technique for increasing the cooling efficiency.

JP 2010-268586 A JP 2007-244065 A

  By the way, the techniques disclosed in Patent Documents 1 and 2 described above basically reduce the thermal resistance between the teeth of the stator core and the coil and increase the amount of heat conduction from the coil to the teeth, thereby improving the cooling efficiency. It is something to enhance. For this reason, in the techniques disclosed in Patent Documents 1 and 2, the coil is wound around the teeth of the stator with high density without a gap. When such a technique can sufficiently cool the coil, no particular problem occurs.

  However, an electric motor that is miniaturized and has an increased output density dramatically increases the amount of heat generated by the motor. For this reason, when the coil is wound around the teeth at a high density without a gap as in the techniques disclosed in Patent Documents 1 and 2 described above, the coil may not be sufficiently cooled. Then, there is a problem that the temperature of the coil is likely to rise, and the loss (heat generation) may increase.

  This invention is made | formed in view of the said situation, and it aims at providing the rotary machine which can cool efficiently the coil currently wound with high density without the clearance gap.

In order to solve the above problems, a rotating machine according to the present invention includes a rotor (20) rotatable around a rotating shaft (10) and a stator (30) arranged around the rotor (30). 1), the stator includes a stator core (31) having a plurality of teeth (31b) arranged along the rotation direction of the rotor, and a coil (32) wound around the teeth. The teeth have a cross-sectional shape in which gaps (C1, C2) are provided in at least one of the coil and the coil wound around the adjacent teeth.
The rotating machine according to the present invention is characterized in that recesses (R1 to R3) for forming a gap with the coil are formed on at least one side surface of the tooth.
Here, the rotating machine of the present invention is characterized in that the recess formed in the tooth has a cross-sectional shape of any one of a triangular shape, an arc shape, and a rectangular shape.
Alternatively, in the rotating machine of the present invention, the teeth have a circular or elliptical cross-sectional shape.
In the rotating machine of the present invention, an external refrigerant (OL) is applied to at least one of a gap provided between the teeth and the coil and a gap provided between the coils wound around the adjacent teeth. A refrigerant supply unit (S2) for supplying is provided.

  According to the present invention, since the cross-sectional shape of the teeth included in the stator core is formed such that a gap is provided between at least one of the coils and the coil wound around the adjacent teeth, there is no gap around the teeth. There is an effect that it is possible to efficiently cool the coil that is wound at a high density without any interference.

It is a sectional side view which shows the structure of the motor as a rotary machine by 1st Embodiment of this invention. It is a cross-sectional arrow view of the stator along the AA line in FIG. It is an enlarged view of the stator in 1st Embodiment of this invention. It is sectional drawing which shows the modification of the teeth in 1st Embodiment of this invention. It is an enlarged view of the stator in 2nd Embodiment of this invention.

  Hereinafter, a rotating machine according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, a case where the rotating machine is a motor (electric motor) that is rotationally driven by an externally supplied current (for example, a three-phase alternating current) will be described as an example.

[First Embodiment]
FIG. 1 is a side sectional view showing a configuration of a motor as a rotating machine according to a first embodiment of the present invention. As shown in FIG. 1, the motor 1 includes a rotating shaft 10, a rotor 20 (rotor), a stator 30 (stator), and a housing 40, and an electric current supplied from the outside causes the rotor 20 and the stator 30. The rotating shaft 10 is rotationally driven by the magnetic force acting therebetween and the rotor 20 rotating. Hereinafter, the left-right direction in FIG. 1 in which the rotation shaft 10 extends is referred to as an “axial direction”.

  The rotating shaft 10 is a shaft member for transmitting the rotational driving force of the rotor 20 to the outside. The rotary shaft 10 is inserted through the rotor 20 and fixed, and is rotatably supported by bearings B1 and B2 installed in the housing 40. For this reason, the rotation shaft 10 and the rotor 20 rotate integrally around the rotation axis of the rotation shaft 10. As the bearings B1 and B2, rolling bearings such as angular ball bearings can be used, for example.

  The rotor 20 is attached to the rotating shaft 10 and is configured to be rotatable around the rotating shaft 10. Specifically, the rotor 20 includes a rotor core 21, a permanent magnet 22, and an end plate 23. The rotor core 21 is formed by laminating a plurality of electromagnetic steel plates as plate members made of a magnetic material, and is a ring-shaped member through which the rotary shaft 10 described above is inserted.

  The permanent magnets 22 are, for example, rectangular parallelepiped magnets extending in the axial direction, and a plurality of permanent magnets 22 are embedded along the outer periphery of the rotor core 21 on the stator 30 side of the rotor core 21. Thereby, an alternating magnetic field is formed along the outer periphery of the rotor core 21. The end plate 23 is a disk-shaped member that is provided at both ends of the rotor core 21 in the axial direction (lamination direction of the electromagnetic steel plates) and sandwiches the rotor core 21 in the axial direction.

  The stator 30 includes a stator core 31 and a coil 32, and is fixed to an inner peripheral surface of a body member 41 that forms a part of the housing 40 so as to surround the rotor 20 along the rotation direction of the rotary shaft 10. A rotating magnetic field is formed along the outer circumferential direction of the rotor 20 in accordance with the current supplied to the coil 32 from the outside. The stator core 31 provided in the stator 30 is an annular member configured by laminating a plurality of electromagnetic steel plates as plate members made of a magnetic material, like the rotor core 21 of the rotor 20 described above, and on the inner peripheral side thereof. Is provided with a rotor 20. The stator core 31 has an inner diameter such that an annular gap (air gap G) having a preset size is formed between the inner peripheral surface of the stator core 31 and the outer peripheral surface of the rotor 20.

  2 is a cross-sectional view of the stator taken along line AA in FIG. As shown in FIG. 2, the stator core 31 includes an annular yoke 31 a and a plurality of teeth 31 b arranged along the circumferential direction D1 of the yoke 31 a. A gap between adjacent teeth 31b is a slot 31c in which the coil 32 is inserted. In FIG. 2, the stator core 31 provided with eight teeth 31 b and eight slots 31 c is illustrated to avoid complication, but the number of these can be arbitrarily set. In FIG. 2, the coils 32 wound around the adjacent teeth 31 b are illustrated as being separated from each other, but these coils 32 may be in contact within the slot 31 c.

  The teeth 31b provided in the stator core 31 function as magnetic poles when a three-phase alternating current is supplied to the coil 32 inserted in the slot 31c, and are formed so as to protrude toward the center of the yoke 31a. Yes. The tip of the tooth 31b has a shape extending in the circumferential direction D1 of the yoke 31a so as to cover a part of the opening of the slot 31c. In other words, a protrusion Q1 formed so as to extend in one direction D11 in the circumferential direction D1 and a protrusion Q2 formed so as to extend in the other direction D12 in the circumferential direction D1 are formed at the tip of the tooth. Yes. The shape of the tip of the tooth 31b is such that the magnetic coupling between the rotor 20 and the stator 30 is enhanced to improve the performance of the motor 1, and the coil accommodated in the slot 31c is prevented from jumping out. Because.

  3A and 3B are enlarged views of the stator according to the first embodiment of the present invention, where FIG. 3A is a perspective perspective view, and FIG. 3B is a cross-sectional view of teeth provided on the stator. In FIG. 3A, the coils 32 wound around the adjacent teeth 31b are shown separated from each other, but these coils 32 may be in contact with each other as shown in FIG. 3B. . As shown in FIG. 3, the root portion of the tooth 31 b (the portion excluding the tip portion where the protruding portions Q <b> 1 and Q <b> 2 are formed) has a substantially quadrangular prism shape including four side surfaces. Of these four side surfaces, two side surfaces intersecting the circumferential direction D1 of the yoke 31a are formed with a recess R1 having a triangular cross-sectional shape.

  The reason why the concave portion R1 is formed in the root portion of the tooth 31b in this manner is to efficiently cool the coil 32 even when the coil 32 is wound around the tooth 31b with a high density without a gap. In other words, when the recess R <b> 1 is formed in the root portion of the tooth 31, the gap C <b> 1 is provided between the tooth 31 b and the coil 32 when the coil 32 is wound around the root portion of the tooth 31. If the cooling oil OL is supplied to the gap C1, the coil 32 can be directly cooled, so that the coil 32 can be efficiently cooled.

  FIG. 4 is a cross-sectional view showing a modification of the tooth in the first embodiment of the present invention. As shown in FIG. 4 (a), the tooth 31b may have a recess R2 having a circular cross section formed on two side surfaces intersecting the circumferential direction D1 of the yoke 31a. Further, as shown in FIGS. 4B and 4C, the tooth 31b has a recess R1 having a triangular cross section or a recess R2 having a circular cross section along the circumferential direction D1 of the yoke 31a. It may be formed on one side.

  Further, as shown in FIG. 4D, the tooth 31b includes a concave portion R1 having a triangular cross-sectional shape on all side surfaces of the root portion (two side surfaces intersecting the circumferential direction D1 of the yoke 31a and the circumferential direction of the yoke 31a). It may be formed on two side surfaces along D1. The same applies to the case where the recess R2 having a circular cross-sectional shape is formed. Further, as shown in FIG. 4 (e), a recess R3 having a rectangular cross-sectional shape may be formed on all side surfaces of the root portion, and the similar recess R3 is provided in the circumferential direction of the yoke 31a. It may be formed only on the two side surfaces intersecting D1, or may be formed only on the two side surfaces along the circumferential direction D1 of the yoke 31a.

  The shape of the recess formed in the tooth 31b is limited to the recess R1 whose cross-sectional shape described above is a triangle, the recess R2 whose cross-sectional shape is an arc shape, and the recess R3 whose cross-sectional shape is a rectangular shape. Any shape can be used. The shape of the recess formed in the tooth 31b is appropriately determined according to, for example, required cooling performance, the size and shape of the tooth, the strength of the tooth, and the like.

  The coil 32 is inserted in the slot 31c formed in the stator core 31 in the state wound around each of the teeth 31b, and forms the magnetic pole according to the electric current supplied from the outside. Here, the coil 32 includes a first coil to which a U-phase current is supplied, a second coil to which a V-phase current is supplied, and a third coil to which a W-phase current is supplied. Thus, the first to third coils are sequentially arranged in the circumferential direction of the stator core 31. For this reason, when a three-phase alternating current is supplied to the coil 32, a rotating magnetic field is formed along the inner peripheral surface of the stator core 31.

  The coil 32 is attached to the stator core 31 such that the coil end portion 32 a protrudes from both end portions of the stator core 31. That is, as shown in FIG. 1, the coil end portion 32 a protrudes leftward from the end on the left side in the axial direction of the stator core 31, and the coil end portion 32 a protrudes from the end on the right in the axial direction of the stator core 31. It is done.

  In addition, annular partition members 33 a and 33 b concentric with the rotary shaft 10 are provided at both ends of the stator core 31. The partition members 33a and 33b are provided to separate the space S1 in which the rotor 20 is disposed and the space S2 (refrigerant supply portion) in which the coil end portion 32a is disposed. By separating the spaces S1 and S2 by the partition members 33a and 33b, the cooling oil OL supplied from the oil supply port P1 is prevented from entering the air gap G, and the teeth 31b of the stator core 31 and Oil OL can be supplied to a gap C1 provided between the coil 32 and the coil 32. In addition, although illustration is abbreviate | omitted, between the protrusion parts Q1 and Q2 formed in the front-end | tip part of the teeth 31b is a mold etc., oil OL penetrates into the air gap G from between the protrusion parts Q1 and Q2. Measures are taken to prevent this.

  The housing 40 includes a body member 41, a left side wall member 42, and a right side wall member 43. The housing 40 houses a part of the rotary shaft 10, the rotor 20, and the stator 30, and forms the outer shape of the motor 1. The body member 41 is formed of an iron alloy or the like, and is a cylindrical member that is open at both ends in the axial direction. The stator 30 described above is fixed to the inner peripheral surface of the body member 41.

  In addition, an oil supply port P1 that guides cooling oil OL (refrigerant) supplied from the outside to the space S2 in the housing 40 is provided in the upper part of the body member 41 in the vertical direction. Below, an oil discharge port P <b> 2 for discharging the oil OL through the space S <b> 2 in the housing 40 to the outside of the housing 40 is provided. The oil supply port P1 and the oil discharge port P2 may be provided at a plurality of locations in order to increase the cooling efficiency.

  The left side wall member 42 and the right side wall member 43 are substantially disk-shaped members formed of an iron alloy or the like, and the outer diameter thereof is set to be approximately the same as the outer diameter of the body member 41. The left opening portion and the right opening portion are respectively attached so as to be closed. In the central portions of the left side wall member 42 and the right side wall member 43, circular hole portions into which the bearings B1 and B2 supporting the rotating shaft 10 are inserted are formed.

  Next, the operation of the motor 1 in the above configuration will be briefly described. When a three-phase alternating current from the outside is supplied to the motor 1, a current of each phase of the three-phase alternating current flows in the coil 32 (first to third coils) provided in the stator 30, according to the supplied current. A rotating magnetic field is formed along the rotation direction of the rotor 20. Then, the rotor core in which an alternating magnetic field is formed along the outer periphery interacts with the rotating magnetic field, and the rotor 20 is rotated by generating an attractive force and a repulsive force. As a result, the rotating shaft 10 rotates integrally with the rotor 20. Thus, the rotational driving force of the rotary shaft 10 is transmitted to the outside.

  When the motor 1 is driven, cooling oil OL is supplied to the oil supply port P1 by a pump (not shown) or the like and guided into the space S2. The oil OL guided to the space S2 is dropped on the coil end portion 32a and moves downward through the coil end portion 32a, or is supplied to a gap C1 provided between the tooth 31b of the stator core 31 and the coil 32. Is done. As a result, the coil end portion 32a of the coil 32 is directly cooled by the oil OL, and the inner peripheral portion of the coil 32 wound around the tooth 31b is directly cooled by the oil OL. Can be cooled.

  Here, the interior of the housing 40 is separated by the partition members 33a and 33b into a space S1 in which the rotor 20 is disposed and a space S2 in which the coil end portion 32a is disposed. Even if the oil OL is supplied into the space S2, the oil OL can be prevented from entering the air gap G. The oil OL that has moved down through the coil end portion 32a and the oil OL that has moved down through the gap C1 are discharged to the outside through the oil discharge port P2.

  As described above, in the present embodiment, the clearance C1 is formed between the tooth 31b and the coil 32 by forming the recesses R1 to R3 having a triangular, arc, or rectangular cross-sectional shape in the teeth 31b of the stator core 31. Provided. As a result, oil OL can be supplied to the gap C1 between the tooth 31b and the coil 32, and the coil 32 can be efficiently cooled.

[Second Embodiment]
Next, a motor as a rotating machine according to a second embodiment of the present invention will be described. The overall configuration of the motor of this embodiment is substantially the same as that of the motor 1 of the first embodiment, but the cross-sectional shape of the teeth provided on the stator core 31 is different from that of the motor 1 of the first embodiment. FIGS. 5A and 5B are enlarged views of the stator according to the second embodiment of the present invention, in which FIG. 5A is a perspective perspective view, and FIG. 5B is a cross-sectional view of teeth provided on the stator. In FIG. 5, members corresponding to those shown in FIG. 3 are denoted by the same reference numerals. 5 (a) and 5 (b), the coils 32 wound around the adjacent teeth 31b are shown separated from each other, but these coils 32 are in contact with each other as in FIG. 3 (b). May be.

  As shown in FIG. 5, in this embodiment, the root part of the teeth 31b is cylindrical. Therefore, the cross-sectional shape of the teeth 31b is a circle. In this way, the cross-sectional shape of the teeth 31b is circular, as in the first embodiment, even if the coils 32 are wound around the teeth 31b at a high density without a gap. This is for cooling. That is, when the cross-sectional shape of the root portion of the tooth 31b is circular, the coil 32 is wound around the root portion of the tooth 31b in an annular shape, and therefore, between the coils 32 wound around the adjacent teeth 31b. A gap C2 is provided. If the cooling oil OL is supplied to the gap C2, the coil 32 can be directly cooled, so that the coil 32 can be efficiently cooled.

  Here, as shown in FIG. 3B, when the cross-sectional shape of the tooth 31b is a substantially quadrangular prism shape, the shape of the coil 32 wound around the tooth 31b is a square ring shape. For this reason, when the coil 32 wound around the adjacent teeth 31b is in contact (or close enough to contact), it becomes difficult to supply the oil OL between the coils 32. The cooling efficiency of 32 cannot be increased. On the other hand, when the cross-sectional shape of the teeth 31b is circular as in the present embodiment, the shape of the coil 32 wound around the teeth 31b becomes an annular shape. Then, even if the coil 32 wound around the adjacent teeth 31b is in contact, the gap C2 is provided between the coils 32 and it becomes easy to supply the oil OL between the coils 32. The cooling efficiency of the coil 32 can be increased.

  As described above, in this embodiment, the gap C2 is provided between the coils 32 wound around the adjacent teeth 31b by making the cross-sectional shape of the teeth 31b of the stator core 31 circular. As a result, oil OL can be supplied to the gap C2 between the coils 32 wound around the adjacent teeth 31b, and the coils 32 can be efficiently cooled. In addition, the cross-sectional shape of the teeth 31b may be an elliptical shape other than the circular shape.

  As mentioned above, although the rotary machine by embodiment of this invention was demonstrated, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, in the above-described embodiment, the case where the stator core 31 is formed by laminating a plurality of electromagnetic steel plates as plate materials made of a magnetic material has been described as an example. However, a powdered magnetic material is pressure-molded. It may be formed by this.

  Moreover, in the said 1st Embodiment, the clearance gap C1 was provided between the teeth 31b and the coil 32, and the said 2nd Embodiment demonstrated the example which provides the clearance gap C2 between the coils 32 wound by the adjacent teeth 31b. However, these first and second embodiments may be combined. For example, the coil 32 wound around the tooth 31b adjacent to the gap C1 between the tooth 31b and the coil 32 is formed by making the cross-sectional shape of the root part of the tooth 31b circular and forming a recess on the side surface of the root part. A gap C2 may be provided between them. By providing both the gaps C1 and C2, the cooling efficiency of the coil 32 can be further increased.

  Furthermore, in the said embodiment, although demonstrated taking the motor which is 1 type of an electric motor as an example, this invention is applicable also to a generator.

DESCRIPTION OF SYMBOLS 1 Motor 10 Rotating shaft 20 Rotor 30 Stator 31 Stator core 31b Teeth 32 Coil C1, C2 Crevice OL Oil R1-R3 Recess S2 Space

Claims (5)

In a rotating machine comprising a rotor rotatable around a rotation axis, and a stator arranged around the rotor,
The stator includes a stator core having a plurality of teeth arranged along the rotation direction of the rotor, and a coil wound around the teeth,
The tooth has a shape in which a clearance is provided in at least one of a cross-sectional shape between the coil and a coil wound around an adjacent tooth.   2. The rotating machine according to claim 1, wherein a concave portion for forming a gap with the coil is formed on at least one side surface of the tooth.   3. The rotating machine according to claim 2, wherein the recess formed in the tooth has a cross-sectional shape of any one of a triangular shape, an arc shape, and a rectangular shape.   The rotating machine according to claim 1, wherein the teeth have a circular or elliptical cross-sectional shape.   It is provided with a refrigerant supply part which supplies refrigerant from the outside to at least one of a gap provided between the teeth and the coil and a gap provided between the coils wound around the adjacent teeth. The rotating machine according to any one of claims 1 to 4.

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