WO2014061430A1

WO2014061430A1 - Rotating electrical machine

Info

Publication number: WO2014061430A1
Application number: PCT/JP2013/076462
Authority: WO
Inventors: 内藤　英治; 利夫石川; 亮一石堂; 邦博大澤
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2012-10-15
Filing date: 2013-09-30
Publication date: 2014-04-24
Also published as: JP2014082821A

Abstract

The purpose of the present invention is to provide a rotating electrical machine that has excellent productivity and reduces the size of a coil end part. In the rotating electrical machine comprising: a stator core having a plurality of radially formed slots opened toward the inner peripheral surface; and a rotor rotatably supported through a gap on the inner side of the stator core, the plurality of slots being wound by a stator winding via an insulating body, the stator winding is constituted by an annular coil made of a wire having a rectangular cross-section, and is wound into a hexagonal shape with a bent portion, and the annular coil has two slot insertion parts to be inserted into the plurality of slots, including one slot insertion part arranged on the inner peripheral side of the slot and the other slot insertion part arranged on the outer peripheral side of the slot with a recessed shape formed in proximity of the bent portion of the annular coil.

Description

Rotating electric machine

The present invention relates to a rotating electrical machine.

In recent years, vehicles have been developed with an emphasis on efficiency to reduce fuel consumption and reduce CO ₂ emissions. High output, high efficiency, and low price are also required for rotating electrical machines for vehicles. In response to these demands, improving the stator is expected to be particularly effective.

In general, a stator used for a generator or a motor is inserted into a stator core having a plurality of slots opened in an inner circumferential surface in the circumferential direction, and wound around a tooth portion between the slots. And a plurality of stator windings.

時 When manufacturing the stator, the stator winding is inserted from the slot opening of the stator core. Since the slot opening is narrow, the insertion operation of the stator winding becomes complicated. Furthermore, since the coil interferes at the coil end portion, it is difficult to increase the space factor of the stator winding.

To solve these problems, for example, in Patent Document 1, a stator winding is attached to a stator core on a flat plate, and both ends of the stator core are annular so that slot openings are disposed on the inner peripheral side. An alternator has been proposed in which a stator is constructed by molding into a shape to improve the space factor. Further, Patent Document 2 proposes a method in which a rectangular wire having a substantially rectangular cross section is wound continuously by overlapping winding to improve the space factor of the stator winding.

Japanese Patent No. 3310967 JP 2008-167567 A

However, since the one described in Patent Document 1 is attached to the stator core and formed into an annular shape, it is necessary to consider damage to the coating of the coil wire. Moreover, when using a flat wire as a strand, it is necessary to consider the direction of a flat wire. For this reason, a high molding technique is required, and there is a problem in terms of quality and productivity particularly in a rotating electric machine used at a high voltage.

Also, in the device described in Patent Document 2, the shape of the coil end portion in the continuous winding is important, and the inclined portion of the coil end is wound and molded with the same length. For this reason, at the time of coil insertion or coil forming, it is expanded on the arc according to the slot pitch. At this time, stress may occur in the coil due to a dimensional difference between the coil end inner periphery side and the outer periphery side in the coil end portion. In addition, this dimensional difference is accumulated in the coil turn portion which is the apex of the coil end, the axial alignment is poor at the coil end apex portion, the gap between the coils becomes large, and the coil end becomes high as a result. There is a problem.

Therefore, the present invention provides a rotating electrical machine that is excellent in productivity and that has a reduced coil end portion.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. To give an example, a stator core in which a plurality of slots that open toward the inner peripheral surface are formed radially, A rotating electrical machine having a stator winding wound around the plurality of slots via an insulator, and the stator winding includes: A conducting wire having a rectangular cross section is formed by an annular coil wound in a hexagonal shape having a bent portion, and the annular coil has two slot insertion portions to be attached to the plurality of slots, and one slot insertion portion is The other slot insertion portion is disposed on the outer periphery side of the slot, and a concave shape is formed in the vicinity of the bent portion of the annular coil.

According to the present invention, it is possible to provide a rotating electrical machine that is excellent in productivity and has a reduced coil end portion. Problems, configurations, and effects other than those described above will become apparent from the description of the following examples.

Sectional drawing which shows the whole structure of a rotary electric machine. The perspective view from the rear side of a stator. The circuit diagram of a stator. The perspective view of the stator winding | coil of a U1 phase A coil. The perspective view of an annular coil. FIG. 6 is a detailed view of a concave shape of the annular coil in FIG. 5. The figure which expanded the annular coil of FIG.

Hereinafter, examples will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the overall configuration of a rotating electrical machine according to an embodiment of the present invention. Here, the vehicle alternator 23 is used as an example of the rotating electrical machine. In the following description, “axial direction” refers to a direction along the rotation axis of the rotating electrical machine. The circumferential direction refers to the direction along the rotational direction of the rotating electrical machine. The “radial direction” refers to a radial direction (radial direction) when the rotational axis of the rotating electrical machine is the center. “Inner circumference side” refers to the radially inner side (inner diameter side), and “outer circumference side” refers to the opposite direction, that is, the radially outer side (outer diameter side).

A vehicle AC generator 23 that is a rotating electrical machine includes a rotor 4 and a stator 5. The rotor 4 includes a field winding 13 at the center of the shaft 2, and a rotor core composed of a front claw-shaped magnetic pole 11 and a rear claw-shaped magnetic pole 12 formed of a magnetic material on both sides of the rotor 4. It arrange | positions so that it may pinch | interpose from both sides so that the coil | winding 13 may be covered. The front claw-shaped magnetic pole 11 and the rear claw-shaped magnetic pole 12 are arranged so that the claw portions face each other and one claw-shaped magnetic pole meshes with the other claw-shaped magnetic pole. The rotor 4 is arranged on the inner peripheral side of the stator 5 so as to face each other with a slight gap. The rotor 4 is rotatably supported by inserting the shaft 2 through the inner rings of the front bearing 3 and the rear bearing 10.

The stator 5 includes a stator core 6 and a stator winding 7. The stator core 6 is formed by laminating a plurality of thin steel plates formed in an annular shape, and has a protruding tooth portion (tooth) on the inner peripheral side, and a slot is formed between each tooth portion. In each slot, the stator winding 7 of each phase is inserted and mounted in each slot across a plurality of teeth. Both ends of the stator 5 are held by a front bracket 18 and a rear bracket 19.

The pulley 1 is attached to one end of the shaft 2. A slip ring 14 is provided at the other end of the shaft 2 and is in contact with the brush 15 to supply power to the field winding 13. Further, a front fan 16 and a rear fan 17 which are cooling fans having a plurality of blades on the outer peripheral side are provided on both end surfaces of the front claw magnetic pole 11 and the rear claw magnetic pole 12 of the rotor 4, respectively. As indicated by a broken line, the cooling air CW is circulated so as to introduce air from outside and discharge the air cooled inside by centrifugal force. The stator winding 7 is cooled by the cooling air CW.

The stator winding 7 is composed of two sets of three-phase windings in this embodiment, and the lead wire of each winding is connected to the rectifier circuit 20. The rectifier circuit 20 is composed of a rectifier element such as a diode, and constitutes a full-wave rectifier circuit. For example, in the case of a diode, the cathode terminal is connected to the diode connection terminal 21. The anode side terminal is electrically connected to the vehicle alternator main body. The rear cover 22 serves as a protective cover for the rectifier circuit 20.

Next, the power generation operation will be described.

First, since the rotation is transmitted from the crankshaft to the pulley 1 through the belt as the engine starts, the rotor 4 is rotated through the shaft 2. Here, when a direct current is supplied from the brush 15 to the field winding 13 provided in the rotor 4 via the slip ring 14, a magnetic flux that circulates around the inner and outer circumferences of the field winding 13 is generated. N-poles or S-poles are alternately formed in the circumferential direction on the front-side claw-shaped magnetic pole 11 and the rear-side claw-shaped magnetic pole 12. The magnetic flux generated by the field winding 13 circulates around the stator winding 7 from the N pole of the front claw-shaped magnetic pole 11 through the stator core 6, and the S of the rear claw-shaped magnetic pole 12 of the rotor 4. A magnetic circuit that circulates around the rotor 4 and the stator 5 is formed by reaching the pole. Since the magnetic flux generated in the rotor is linked to the stator winding 7 in this way, AC induction is induced in each of the U1-phase, U2-phase, V1-phase, V2-phase, W1-phase, and W2-phase stator windings 7. A voltage is generated, and an AC induced voltage for six phases is generated as a whole.

The AC voltage generated in this way is full-wave rectified and converted into a DC voltage by a rectifier circuit 20 composed of a rectifier element such as a diode. The current supplied to the field winding 13 is controlled by an IC regulator (not shown) so that the rectified DC voltage becomes a constant voltage.

Next, the configuration of the stator used in the rotating electrical machine according to this embodiment will be described with reference to FIGS.

FIG. 2 is a perspective view from the rear side of the stator 5. The stator 5 is connected to each phase through an annular stator core 6 having a plurality of slots in the circumferential direction of the inner peripheral surface and a U-shaped insulating paper 8 attached to the inner peripheral surface of each slot. The stator winding 7 is mounted, and a slot wedge 9 is provided on the innermost circumferential side of the slot in order to hold the stator winding 7 in the slot. In this embodiment, the number of slots is 72.

The portion protruding in the axial direction from the slot of the stator core 6 is a coil end 72-a on the lead wire side and a coil end 72-b on the opposite lead wire side between the two slots. Further, as shown in the figure, 24 lead lines 71 are taken out. Since the number of lead wires 71 is 24, the number of coils is 12.

Here, a predetermined gap (1 mm or more) is provided between the respective winding coils of the stator winding. This is because when the rotating electrical machine is a motor, the applied voltage is as high as 300 V or 600 V, and insulation between phases is ensured by a gap.

On the other hand, in the case of the vehicle alternator as in this embodiment, the output voltage is generally as low as 14V to 28V, and the withstand voltage between the lines is not so required. Therefore, an insulating material (insulating varnish) is interposed in the space between the respective winding coils of the stator winding.

FIG. 3 is a circuit diagram (connection diagram) of the stator winding. The configuration of this embodiment is a delta connection configuration in which the stator windings are connected in a triangular shape, and two types of coils, a first winding 7-1 and a second winding 7-2, are connected in parallel. Configured. The first winding 7-1 is connected to the rectifier 20-1, and the second winding 7-2 is connected to the rectifier 20-2.

The delta-connected first winding 7-1 includes six coils (two U-phase coils 7U1-A and 7U1-B connected in parallel and two V-phase coils 7V1-A connected in parallel). , 7V1-B and two W-phase coils 7W1-A, 7W1-B) connected in parallel. Similarly, in the second winding 7-2, six coils are delta-connected.

The above windings are delta-connected, but a rotating electrical machine can be established even if they are configured in series connection and star connection (Y connection).

FIG. 4 is a perspective view of one coil (for example, U-phase coil 7U1-A) attached to the stator core 6. FIG. The number of turns of the annular coil 76 is, for example, 5 turns (5T). It consists of six annular coils 76, five connecting wires 73 that connect between the annular coils 76, and two lead wires 71 that connect the annular coils 76 located at both ends to the outside.

The U phase of the first winding 7-1 includes a U phase coil 7U1-A and a U phase coil 7U1-B. Both the U-phase coil 7U1-A and the U-phase coil 7U1-B have a configuration in which the jumper wire 73 is arranged on the lead wire 71 side, that is, the arrangement of the jumper wires is concentrated on the lead wire side.

In the above description, the U-phase coil of the first winding 7-1 is taken as an example, but the above-described configuration is common to the coils of the first winding 7-1 and the second winding 7-2. When all twelve coils are attached to the stator core 6, the state shown in FIG.

FIG. 5 is a perspective view showing the form of one annular coil 76. The annular coil 76 is substantially hexagonal (tortoise-shaped), and is attached to a lead wire 71, coil end portions 74-a and 74-b protruding in the axial direction of the stator core, and a slot portion of the stator core. Slot insertion portions 75-a and 75-b, and a crossover 73 connecting the annular coils. The coil end portions 74-a and 74-b include coil turn portions 74ct-a and 74ct-b that are folded back in a U shape at the triangular apexes of the coil end portions.

Conventionally, as shown in Patent Document 2, a tortoiseshell-shaped coil has been formed by winding a conductive wire in the flatwise direction and forming it while sliding or twisting in the rotational direction. Also, the stator core 6 was mounted in a tortoiseshell shape while being twisted when inserted into the slot portion. The inclined part of the coil end is wound and formed with the same length. For this reason, at the time of coil insertion or coil forming, it is expanded on the arc according to the slot pitch. At this time, stress may occur in the coil due to a dimensional difference between the coil end inner periphery side and the outer periphery side in the coil end portion. In addition, this dimensional difference is accumulated in the coil turn portion which is the apex of the coil end, the axial alignment is poor at the coil end apex portion, the gap between the coils becomes large, and the coil end becomes high as a result. There was a problem.

As a countermeasure, restraint or molding of the coil end apex can suppress alignment and the height of the coil end, but stress on the coil at the coil end increases damage to the coil coating. In some cases, however, cracks or the cross-sectional area of the coil becomes small, resulting in quality problems.

Therefore, in this embodiment, the concave shape 78 having a different size is formed near the bent portion of the annular coil 76. Accordingly, when the annular coil is inserted in the outer peripheral direction of the stator slot while expanding the annular coil in the radial direction from the inner peripheral side of the stator slot, the annular coil is deformed three-dimensionally. That is, flexibility in the radial direction and the axial direction in the rigid state of the annular coil 76 can be obtained. For this reason, the insertability of the annular coil 76 into the stator core is improved, and the height of the coil end portion can be minimized.

FIG. 6 is a detailed shape diagram showing the concave shape 77 of the annular coil. A concave shape 77 is formed in the vicinity of the slot insertion portions 75-a and 75-b attached to the slot portions of the stator core of the annular coil 76. The concave shape 77 forms a three-dimensional shape in which the coil turn portions 74ct-a and 74ct-b are inclined when the annular coil is expanded in the radial direction, thereby minimizing the height of the coil end portion. It can be suppressed.

FIG. 7 is a view showing a shape when the annular coil 76 of FIG. 6 is expanded in the radial direction. An arrow RD in FIG. 7 indicates the radial direction. When the annular coil 76 is expanded, the concave shape 77 is crushed. Thereby, the stress (distortion which arises in a coil end part) applied to a coil end part at the time of a deformation | transformation of the annular coil 76 is absorbed, and the damage to the film of a coil can be reduced. Moreover, since the axial alignment of the coil end apex portion can be maintained, the height of the coil end can be suppressed. L2 in FIG. 7 indicates the length (height) of the annular coil 76 in the axial direction. L2 is smaller than the length L1 in the axial direction before deformation (FIG. 6).

As described above, according to the present invention, the insertion property of the annular coil and the height of the coil end portion can be minimized, and a high-quality, high-output and high-efficiency rotating electrical machine can be provided.

In the above-described embodiment, the stator winding 7 is mounted from the slot inner peripheral side of the stator core 6. However, the coil of the present invention can also be applied to a deployment core system as disclosed in Patent Document 1 (a system in which a stator core formed by a rectangular conductor wire is mounted on a flat stator iron core and a deployment core is rounded). Forms can be applied. In this case as well, the stress on the coil end portion due to the round forming of the stator core can be suppressed, the force required for the round forming can be reduced, and a high quality and high quality stator can be provided.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. 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. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of the embodiment.

For example, the stator winding of the example has a configuration in which six annular coils are connected via a jumper wire. However, a single annular coil is arranged, and the lead wires of each annular coil are joined by welding or the like, or each lead wire is connected by a bus bar or the like to form a Δ connection (delta connection) or a Y connection (star connection). However, the same effect can be obtained.

Further, the stator winding of the example had a winding pitch of 5/6 (electrical angle 150 °). However, the present invention can be applied even when the winding pitch is 4/6 (electrical angle 120 °) or 6/6 (electrical angle 180 °), and the same effects as those described in the embodiments can be obtained. It is done.

In addition, the stator of the example had two sets of three-phase windings. However, the present invention can be applied even to multi-phase windings such as three-phase, five-phase, and seven-phase, and the same effects as those described in the embodiments can be obtained.

In the embodiment, the vehicular AC generator has been described as an example of the rotating electrical machine. However, the present invention can also be applied to a motor that outputs rotational force, a motor generator that combines power generation and driving, and the like. In particular, the motor can be applied as a stator to a motor for driving a hybrid vehicle or an electric four-wheel drive vehicle, a motor for driving a pump, or the like.

DESCRIPTION OF SYMBOLS 1 Pulley 2 Shaft 3 Front bearing 4 Rotor 5 Stator 6 Stator iron core 7 Stator winding 8 Insulating paper 9 Slot wedge 10 Rear bearing 11 Front side claw magnetic pole 12 Rear side claw magnetic pole 13 Field winding 14 Slip ring 15 Brush 16 Front fan 17 Rear fan 18 Front bracket 19 Rear bracket 20 Rectifier circuit 21 Diode connection terminal 22 Rear cover 23 Vehicle alternator 71 Lead wire 73 Crossover wire 74-a Coil end portion (lead wire side)
74-b Coil end (on the lead wire side)
75-a Slot insertion part (inserted on the inner circumference side of the stator core of the slot)
75-b Slot insertion part (inserted on the outer periphery of the stator core of the slot)
76 Annular coil 77 Concave shape

Claims

A stator core in which a plurality of slots that open toward the inner peripheral surface are radially formed;
A rotor supported rotatably via a gap on the inner peripheral side of the stator core;
In the rotating electrical machine in which the stator winding is wound around the plurality of slots via an insulator,
The stator winding is constituted by an annular coil wound in a hexagonal shape with a conductor having a rectangular cross section having a bent portion,
The annular coil has two slot insertion portions mounted in the plurality of slots, one slot insertion portion is disposed on the inner peripheral side of the slot, and the other slot insertion portion is disposed on the outer peripheral side of the slot. ,
A rotating electrical machine in which a concave shape is formed in the vicinity of the bent portion of the annular coil.
In the rotating electrical machine according to claim 1,
A rotating electrical machine in which a plurality of the annular coils are continuously formed via a jumper wire.
The rotating electrical machine according to claim 1, wherein
A rotating electrical machine in which one of the lead wires of the stator winding is disposed at the center of the slot and the other is disposed on the outermost or innermost side of the slot.