JP2009027836A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine capable reducing rotary resistance of a rotor by suppressing a coolant from oozing between the rotor and a stator while cooling a permanent magnet. <P>SOLUTION: The rotary electric machine is provided with: a shaft 58 rotatably arranged and having a coolant channel 45 where a coolant can circulate; a housing hole 24A capable of housing a permanent magnet 31A; and the permanent magnet 31A arranged inside the housing hole 24A. The rotary electric machine is further provided with: a rotor fixed to the shaft 58; an end plate 29 arranged at a rotor axial direction end 10a; a coolant channel 43 formed in the end plate 29 and communicating with the coolant channel 45 via an axial direction end 31a of the permanent magnet 31A so that a coolant can circulate; and a resin 26 which closes the space between openings 25a, 25b of the housing hole 24A positioned at the rotor axial direction ends 10a, 10b and the permanent magnet 31A so as to suppress intrusion of the coolant into the housing hole 24A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine in which a permanent magnet is cooled.

  Conventionally, various electric motors having a cooling function have been proposed. For example, an electric motor described in Patent Document 1 (Japanese Patent Laid-Open No. 2003-169448) supplies lubricating oil supplied to a bearing member to a coil end and cools the coil end.

Moreover, the electric motor described in patent document 2 (Unexamined-Japanese-Patent No. 2006-6091) is provided with the jet nozzle which ejects cooling oil toward the permanent magnet of a rotor, and makes a magnet adsorb | suck a magnetic impurity to a magnet. The cooling oil from which magnetic impurities have been removed is sprayed on the coil. In this way, it is possible to prevent a reduction in the insulation performance of the coil due to the insulating film on the coil surface being damaged.
JP 2003-169448 A JP 2006-6091 A

  In the rotary electric machine described in the above Japanese Patent Laid-Open No. 2006-6091, the lubricating oil enters the housing hole that houses the permanent magnet. Then, the lubricating oil that has entered the accommodation hole oozes out radially outward from the gap between the laminated steel plates constituting the rotor. Then, lubricating oil enters between the rotor and the stator, and the rotational resistance of the rotor increases.

  And in the electric motor described in Unexamined-Japanese-Patent No. 2003-169448, the permanent magnet provided in the stator is not cooled.

  The present invention has been made in view of the above problems, and its purpose is to prevent the refrigerant from seeping out between the rotor and the stator while cooling the permanent magnet, An object of the present invention is to provide a rotating electrical machine in which the rotational resistance of a rotor is reduced.

  A rotating electrical machine according to the present invention is rotatably provided, a rotating shaft formed with a first refrigerant passage through which a refrigerant can flow, an accommodation hole capable of accommodating a permanent magnet, and a permanent magnet provided in the accommodation hole. And a rotor fixed to the rotating shaft. The rotating electrical machine has a stator that faces the rotor and has a plurality of winding phases, an end plate that is provided at an axial end of the rotor, and an axial direction of the permanent magnet that is formed on the end plate. A second refrigerant passage is provided that communicates with the first refrigerant passage through the end portion and allows the refrigerant to flow therethrough. And at least the opening edge part of the accommodation hole located in the axial direction edge part of the said rotor and the obstruction | occlusion member which obstruct | occludes between a permanent magnet and can suppress permeation of the refrigerant | coolant in an accommodation hole are provided.

  Preferably, the closing member is filled in the accommodation hole and extends over both axial end faces located in the axial direction of the rotor. Preferably, at least a part of the axial end of the permanent magnet is exposed from the closing member. Preferably, the closing member is made of resin.

  According to the rotating electrical machine according to the present invention, the permanent magnet can be cooled, and further, the refrigerant can be prevented from entering between the rotor and the stator, thereby reducing the rotational resistance of the rotor. be able to.

  The rotating electrical machine according to the present embodiment will be described with reference to FIGS. Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified.

  FIG. 1 is a cross-sectional view showing a rotating electrical machine according to an embodiment of the present invention. The rotating electrical machine shown in the figure is a motor mounted on a hybrid vehicle that uses an internal combustion engine such as a gasoline engine or a diesel engine and a motor powered by a chargeable / dischargeable secondary battery (battery) as a power source. .

  Referring to FIG. 1, rotating electric machine 100 includes a rotor 10 and a stator 50 disposed on the outer periphery of rotor 10. The rotor 10 is provided on a shaft 58 that extends along the central axis 101. The shaft 58 rotates about the central axis 101 together with the rotor 10.

The rotor 10 includes a rotor core 20 and a permanent magnet 31 embedded in the rotor core 20. That is, the rotating electrical machine 100 is an IPM (Interior Permanent Magnet) motor.
The rotor core 20 has a cylindrical shape along the central axis 101. The rotor core 20 is composed of a plurality of electromagnetic steel plates 21 stacked in the axial direction of the central shaft 101.

  An end plate 29 is provided on the end surface of the rotor 10 located in the direction of the central axis 101.

  The stator 50 includes a stator core 55 and a coil 51 wound around the stator core 55. The stator core 55 is composed of a plurality of electromagnetic steel plates 52 stacked in the axial direction of the central shaft 101. Note that the rotor core 20 and the stator core 55 are not limited to electromagnetic steel plates, and may be formed of, for example, a dust core.

  The coil 51 is electrically connected to the control device 70 by a three-phase cable 60. The three-phase cable 60 includes a U-phase cable 61, a V-phase cable 62, and a W-phase cable 63. The coil 51 includes a U-phase coil, a V-phase coil, and a W-phase coil, and a U-phase cable 61, a V-phase cable 62, and a W-phase cable 63 are connected to terminals of these three coils, respectively.

A torque command value to be output by the rotating electrical machine 100 is sent to the control device 70 from an ECU (Electrical Control Unit) 80 mounted on the hybrid vehicle. The control device 70 generates a motor control current for outputting the torque specified by the torque command value, and supplies the motor control current to the coil 51 via the three-phase cable 60.

  2 is an enlarged cross-sectional view in which a part of FIG. 1 is enlarged, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 3, the rotor 10 is provided with magnet groups 30 </ b> A to 30 </ b> H that define a plurality of magnetic poles. In addition, each magnet group 30A-30H is comprised by two permanent magnets, for example, magnet group 30A is provided with two permanent magnets 31A and 31B. The permanent magnet 31 </ b> A and the permanent magnet 31 </ b> B are arranged in the circumferential direction of the rotor 10. And the magnetic poles of the outer peripheral side of the rotor 10 of the magnet groups 30A to 30H adjacent in the circumferential direction of the rotor 10 are different from each other.

  The rotating electrical machine 100 includes a magnet cooling passage 40 that cools the permanent magnets 31A and 31B included in the magnet groups 30A to 30H. The magnet cooling passage 40 includes a refrigerant passage 45 formed in the shaft 58, a refrigerant passage 43 communicating with the refrigerant passage 45, defined by the end plate 29 and the axial end faces 10 a and 10 b of the rotor 10, and a refrigerant A discharge hole 44 communicating with the passage 43 is provided. The refrigerant passage 45 includes an axial passage 41 that extends in the direction of the central axis 101, and a radial passage 42 that is connected to the axial passage 41 and extends in the radial direction of the shaft 58. The radial passage 42 extends toward each of the magnet groups 30A to 30H. The refrigerant passage 43 extends from the radially inner side to the outer side of the rotor 10 so that the circumferential length of the rotor 10 increases.

  And the refrigerant path 43 passes along the axial direction end surfaces 31a and 31b of each permanent magnet which comprises each magnet group 30A-30H. For this reason, the permanent magnets 31 </ b> A and 31 </ b> B are cooled by the refrigerant A flowing through the refrigerant passage 43. Note that the refrigerant A flowing through the axial passage 41 enters the radial passage 42, and the refrigerant A enters the refrigerant passage 43.

Here, as shown in FIG. 2, the permanent magnet 31 </ b> A is accommodated in a magnet accommodation hole 24 </ b> A formed in the rotor core 20. The magnet housing hole 24 </ b> A extends in the direction of the central axis 101 and reaches both axial end faces 10 a and 10 b of the rotor 10. The magnet housing hole 24A is filled with a resin (blocking member) 26. The resin 26 fills a gap between the inner peripheral surface of the rotor core 20 that defines the magnet accommodation hole 24A and the permanent magnet 31A accommodated therein.
The axial end surfaces 31 a and 31 b of the permanent magnet 31 </ b> A are not covered with the resin 26 and are exposed from the resin 26.

  For this reason, even if the refrigerant A is supplied into the refrigerant passage 43, the refrigerant A can be prevented from penetrating into the magnet housing hole 24A. Thus, since it can suppress that the refrigerant | coolant A penetrates into the magnet accommodating hole 24A, it can suppress that the refrigerant | coolant A oozes out between the electromagnetic steel plates of the rotor core 20 to the outer peripheral surface of the rotor core 20. Thereby, it can suppress that the refrigerant | coolant A enters between the rotor 10 and the stator 50, and can suppress the raise of the rotational resistance of the rotor 10. FIG. In particular, since the resin 26 is formed over substantially the entire inner surface of the rotor core 20 that defines the magnet housing hole 24A, the resin 26 is directed from the inner surface of the rotor 10 that defines the magnet housing hole 24A to the outer surface of the rotor 10. Thus, the refrigerant A can be prevented from oozing out. Furthermore, the permanent magnet 31 can be favorably adhered to the rotor core 20, and the permanent magnet 31 can be favorably fixed to the rotor core 20.

  Since the axial end surfaces 31a and 31b of the permanent magnet 31A are exposed from the resin 26, the permanent magnet 31A is cooled well by the refrigerant A. Thus, by cooling the permanent magnet 31A, the thermal demagnetization of the permanent magnet 31A can be suppressed.

  As described above, the permanent magnets constituting the magnet groups 30 </ b> A to 30 </ b> H are cooled and then discharged from the discharge hole 44. As the resin 26, for example, a resin material such as epoxy, unsaturated polyester, polyamide, polypropylene, polybutylene terephthalate, polyethylene terephthalate, or polyphenylene sulfide can be employed.

  FIG. 4 is a cross-sectional view showing a first modification of the rotating electrical machine according to the embodiment of the present invention. In the example shown in FIG. 4, a resin 26 that closes the gap between the opening edges of the openings 25 a and 25 b of the magnet housing hole 24 </ b> A located on the axial end faces 10 a and 10 b of the rotor 10 and the permanent magnet 31 </ b> A is provided. ing. Also in this rotating electrical machine, since the space between the permanent magnet 31A and the openings 25a and 25b is closed, the refrigerant A can be prevented from entering the magnet accommodation hole 24A. As described above, the resin A is not limited to the case where the resin is filled in the magnet housing hole 24A. Even if the gap between the permanent magnet 31A and the openings 25a and 25b is closed by the resin 26, the refrigerant A is contained in the magnet. It can suppress entering into the hole 24A.

  FIG. 5 is a cross-sectional view showing a second modification of the rotating electrical machine according to the embodiment of the present invention. As shown in FIG. 5, of the electromagnetic steel plate 21, the plate-like closing members 22 a and 22 b located on the axial end faces 10 a and 10 b of the rotor 10 are the opening edges of the openings 25 a and 25 b of the magnet housing hole 24. And the opening part of the clearance gap located between the permanent magnets 31 is obstruct | occluded. Thus, the refrigerant A may be prevented from entering the magnet accommodation hole 24 using a flat plate member.

  Although the embodiment of the present invention has been described above, it should be considered that the embodiment disclosed this time is illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Furthermore, the above numerical values are examples, and are not limited to the above numerical values and ranges.

  The present invention can be applied to a rotating electrical machine, and is particularly suitable for a rotating electrical machine in which a permanent magnet is cooled.

It is sectional drawing which shows the rotary electric machine which concerns on embodiment of this invention. FIG. 2 is an enlarged cross-sectional view in which a part of FIG. 1 is enlarged. It is sectional drawing in the III-III line of FIG. It is sectional drawing which shows the 1st modification of the rotary electric machine which concerns on embodiment of this invention. It is sectional drawing which shows the 2nd modification of the rotary electric machine which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Rotor, 10a, 10b Axial end surface, 20 Rotor core, 21 Electrical steel plate, 24 Magnet accommodation hole, 25a, 25b Opening part, 26 Resin (blocking member), 29 End plate, 30A Magnet group, 31 Permanent magnet, 40 Magnet cooling Passage, 41 axial passage, 42 radial passage, 43 refrigerant passage, 44 discharge hole, 45 refrigerant passage, 50 stator, 100 rotating electrical machine, 101 central axis, A refrigerant.

Claims (4)

A rotating shaft provided rotatably and having a first refrigerant passage through which a refrigerant can flow;
A rotor having a housing hole capable of housing a permanent magnet and a permanent magnet provided in the housing hole, and a rotor fixed to the rotating shaft;
A stator facing the rotor and having a plurality of winding phases;
An end plate provided at an axial end of the rotor;
A second refrigerant passage formed in the end plate, passing through the axial end of the permanent magnet, communicating with the first refrigerant passage, and allowing the refrigerant to flow therethrough;
An opening of the housing hole located at the axial end of the rotor and a closing member capable of closing the space between the permanent magnet and suppressing the refrigerant from entering the housing hole; Rotating electric machine.   2. The rotating electrical machine according to claim 1, wherein the closing member is filled in an accommodation hole and extends over both axial end surfaces located in the axial direction of the rotor.   The rotating electrical machine according to claim 1, wherein at least a part of an axial end portion of the permanent magnet is exposed from the closing member.   The rotating electrical machine according to any one of claims 1 to 3, wherein the closing member is made of resin.

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