WO2011092928A1

WO2011092928A1 - Rotating electric machine

Info

Publication number: WO2011092928A1
Application number: PCT/JP2010/070852
Authority: WO
Inventors: 剛野中
Original assignee: 株式会社安川電機
Priority date: 2010-01-28
Filing date: 2010-11-24
Publication date: 2011-08-04
Also published as: JPWO2011092928A1; CN102668338A

Abstract

Provided is a rotating electric machine provided with a compact water-cooling structure in which lost heat generated in a stator coil is effectively released to a cooling water channel to thereby suppress the temperature increase of the stator coil and enable the passage of a larger electric current at an allowable temperature, thereby improving the rated output. Specifically provided is a rotating electric machine provided with an approximately cylindrical rotor which is supported to be rotatable, a stator, a bracket which supports the stator, and a water-cooling structure, said rotating electric machine being characterized in that the bracket comprises a cooling water channel and comprises a portion which is closely attached to a stator coil with an insulator therebetween.

Description

Rotating electric machine

The present invention relates to a rotating electrical machine such as an EV motor, and more particularly to cooling of a stator coil.

In the rotating electrical machine, the temperature of the stator coil rises due to heat loss due to energization of the load current. In order to obtain a larger output, it is necessary to increase the load current, and the temperature of the stator coil further increases. In many cases, the rated output of a rotating electrical machine is limited to a range where the temperature of the stator coil does not reach the heat-resistant limit temperature, so the cooling method of the stator coil is an important technology indispensable for improving the output of the rotating electrical machine. is there.
A conventional rotary electric machine having a substantially cylindrical rotor rotatably supported, a stator, a bracket for supporting the components, and a water cooling structure has an example in which a cooling water channel is provided in a frame ( For example, see Patent Document 1).
FIG. 14 is a structural example of a rotating electrical machine having a conventional water cooling structure.
In the figure, the rotating electrical machine includes a substantially cylindrical rotor 7 that is rotatably supported, a stator core 2, a stator coil 3 mounted on the stator core, and a load side bracket that supports the components. 4a, an anti-load side bracket 4b, and a frame 1.
A cooling water channel 12 is provided in the frame. The heat generated by the loss generated in the stator coil is radiated to the outside by the cooling water through the insulator, the stator core, and the frame.
In order to increase the thermal conductivity to reach the frame, high

thermal conductivity insulators

10a and 10b are filled between the load side coil end 3a and the anti-load side coil end 3b of the stator coil and the frame.
With the high thermal conductive insulator, the amount of heat generated in the stator coil can be radiated more directly to the frame, and the rated output of the rotating electrical machine can be increased.

Some conventional rotating electrical machines dissipate heat generated by a stator coil attached to a stator core directly to a load side bracket to improve the cooling effect (see, for example, Patent Document 2).
FIG. 15 is an axial sectional view of another conventional rotating electrical machine.
In the figure, a load side coil end 21e of a stator coil 21 made of a plate-shaped conductor mounted on a stator core 22 is formed with an inner peripheral surface and an outer peripheral surface on one cylindrical surface, and an end surface on a single plane. And is in close contact with the groove 25e of the load side bracket 25 via an insulator 24. As a result, the heat generated in the stator coil is directly radiated to the load side bracket and radiated from the load side bracket to the external device.
The coil end of the stator coil is more likely to be in close contact with the load side bracket than the frame, and the heat dissipation effect is greater than with a high thermal conductive insulator as shown in FIG. The amount of heat reaching the load side bracket is dissipated to the external device to which the load side bracket is attached.

Thus, the conventional rotating electrical machine has been devised to dissipate the heat loss generated by the stator coil mounted on the stator core more effectively to the outside.

JP 2002-191149 A (page 6, FIG. 1) JP 2006-050853 A (page 7, FIG. 2)

In the conventional rotating electrical machine shown in Patent Document 1, the amount of heat generated in the stator coil is improved by the heat dissipation because the amount of heat generated in the stator coil is dissipated to the outside by cooling water through the insulator, the stator core, and the frame. The conductive insulator is used together with the effect of directly radiating the heat generated in the stator coil to the frame. However, although a high thermal conductivity insulator is generally superior in thermal conductivity as compared to an insulator, it is significantly inferior in thermal conductivity and has little improvement in heat dissipation effect compared to a metal such as a bracket.

Another conventional rotating electric machine shown in Patent Document 2 has a heat-dissipating effect up to the load-side bracket because the coil end of the stator coil is brought into close contact with the load-side bracket, but does not have a water cooling structure. The heat dissipation from the load side bracket to the outside of the rotating electrical machine has a low limit.

The present invention has been made in view of such problems, and the heat loss generated in the stator coil is effectively radiated to the cooling water channel, the temperature rise of the stator coil is suppressed, and the allowable temperature is exceeded. An object of the present invention is to provide a rotating electrical machine having a compact water-cooling structure that enables larger energization and improves rated output.

In order to solve the above problem, the present invention is configured as follows.
The invention described in claim 1
In a rotating electrical machine having a substantially cylindrical rotor that is rotatably supported, a stator, a bracket that supports the stator, and a water cooling structure,
The bracket is a rotating electrical machine characterized by having a cooling water passage and a portion that is in close contact with the stator coil via an insulator.
The invention according to claim 2
2. The rotating electrical machine according to claim 1, wherein the cooling water passage of the bracket has an opening portion on the motor outer side and does not have an opening portion on the motor inner side.
The invention according to claim 3
2. The rotating electric machine according to claim 1, wherein the stator coil has an air-core coil whose outer shape is press-molded and mounted in a slot portion of the stator core.
The invention according to claim 4
2. The rotating electrical machine according to claim 1, wherein the stator coil has a coil end portion mounted in a distributed winding in a slot portion of the stator core and press-molded on an outer shape.
The invention according to claim 5
2. The rotating electrical machine according to claim 1, wherein the insulator through the stator coil and the bracket is a ring-shaped molded product and is mounted between the coil end portion of the stator coil and the bracket. .
The invention according to claim 6
2. The rotating electrical machine according to claim 1, wherein the insulator through the stator coil and the bracket is a ceramic film processed on the surface of the bracket.

According to the invention of claim 1,
Since the bracket has a cooling water channel and a part that is in close contact with the stator coil via an insulator, the heat loss generated in the stator coil is effectively radiated to the cooling water channel, and the temperature of the stator coil increases. It is possible to provide a rotating electrical machine having a compact water-cooling structure that can suppress energies, enable larger energization with respect to the allowable temperature, and improve the rated output.
According to the invention of claim 2,
Since the cooling water passage of the bracket does not have an opening portion on the inner side of the motor, the cooling water is not immersed on the inner side of the rotating electric machine of the bracket, and the insulation around the stator coil is not lowered.
According to the invention of claim 3,
Since the stator coil is fitted with an air-core coil whose outer shape is press-molded in the slot of the stator core, the coil end of the stator coil can be easily brought into close contact with the bracket, and the amount of heat generated by the stator coil It is easy to radiate heat to the bracket.
According to the invention of claim 4,
The stator coil is installed in a distributed winding in the slot portion of the stator core, and has a coil end portion whose outer shape is press-molded, so that the coil end portion of the stator coil can be easily adhered to the bracket, and the stator coil It is easy to dissipate the amount of heat generated in the bracket.
According to the invention of claim 5,
Since the insulator through the stator coil and the bracket is a ring-shaped product, it can be manufactured at low cost.
According to the invention of claim 6,
Since the insulator through the stator coil and bracket is a ceramic film treated on the surface of the bracket, it is a material that combines high insulation resistance and high thermal conductivity, and is generated in the stator coil while ensuring insulation. It is easy to dissipate heat to the bracket.

FIG. 1 is an axial sectional view of a rotating electrical machine showing a first embodiment of the present invention. Radial sectional view of the motor Illustration of shape of load side bracket Explanatory drawing before mounting the stator coil Illustration of stator coil insulation structure Explanatory drawing after mounting the stator coil Frame installation state explanatory diagram Explanatory drawing of pressure forming of outer shape of stator coil Explanatory drawing of press forming of outer shape of stator coil viewed from the circumferential direction Comparative diagram showing the effect of this example Axial sectional view of a rotating electrical machine showing a second embodiment of the present invention. Radial sectional view of the rotating electrical machine Explanatory drawing which shows the pressure molding method of the load side coil end part Structure example of a rotating electrical machine with a conventional water cooling structure Axial sectional view of another conventional rotating electrical machine

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an axial sectional view of a rotating electrical machine showing a first embodiment of the present invention for use in an EV motor.
In the figure, a rotor core 33 of a rotor 31 of the motor is fixed to a shaft 34 by a load side plate 35 and an anti-load side plate 36, and is connected to a load side via a load-side bearing 37 and an anti-load side bearing 38. The bracket 43 and the anti-load side bracket 44 are rotatably supported.
An encoder portion 41 for detecting the rotational position of the rotor is installed at the end on the side opposite to the load of the shaft.
The stator coil 46 is mounted so as to be in close contact with the load side bracket via the insulator 47. The load-side bracket has a portion that is in close contact with the stator coil via an insulator, and has a cooling water channel 43c, so the amount of heat due to lost heat generated in the stator coil is
Effectively dissipates heat to the cooling water channel, suppresses the temperature rise of the stator coil, enables larger energization with respect to the allowable temperature, and improves the rated output. The cooling water channel is sealed by a cover 50 fastened to the load side bracket by a bolt 55, and the outer O-ring 53 and the inner O-ring 54 are sealed.
Prevents the leakage of cooling water. The amount of heat is radiated to the outside through the outlet pipe 43b together with the cooling water.
The stator coil has an insulator 48 and is insulated from the stator core.
Energization to the stator coil is supplied from the outside through a lead wire (not shown) from the connection portion 42 of the stator coil.
The anti-load side bracket is fastened to the load side bracket by a bolt (not shown) together with the frame 51.

FIG. 2 is a radial sectional view of the motor.
In the figure, the rotor 31 of the motor has an embedded magnet type structure in which a permanent magnet 32 is installed in a rotor core 33 in a V-shape for each pole and constitutes a 10-pole magnetic pole.
The stator has a stator core 45 divided for each tooth and a stator coil 46 wound around concentrated winding and press-molded on the outer shape.

FIG. 3 is an explanatory view of the shape of the load side bracket.
In the figure, the load-side bracket 43 has a portion that is in close contact with the stator coil via an insulator, and has a cooling water channel 43c.
The cooling water is introduced from the introduction pipe 43a, receives the heat amount of the load side bracket while passing through the cooling water passage 43c, and is led out from the lead-out pipe 43b. After being cooled by an external device (not shown), the motor of this embodiment is cooled while repeating the circulation introduced into the load side bracket again.
The cooling fins 43d constitute a cooling water channel and are provided to promote heat exchange from the load side bracket to the cooling water.
The load-side bracket is provided with a bolt hole 43e for attachment to an external device, a fastening bolt hole 43f with a frame, and a screw hole 43g for cover attachment.

FIG. 4 is an explanatory diagram before mounting the stator coil.
In the figure, a stator coil 46 is mounted so that 12 air-core coils whose outer shapes are pressure-molded are in close contact with the load-side bracket 43 via an insulator 47.
The insulator through the stator coil and the load-side bracket is a ceramic film treated on the surface of the load-side bracket, so it is a material that combines high insulation resistance and high thermal conductivity. It is easy to dissipate the heat generated in the coil to the bracket. The ceramic coating is sealed to ensure insulation.

5, the stator coil 46 has an outer insulator 48a and an inner insulator 48b, and is insulated from the stator core by an insulating tape 48c attached in the circumferential direction. Insulated from adjacent stator coils. The insulator is an injection-molded part made of a resin material having good fluidity that can be thinly molded, or a sheet processed part that is obtained by heating and pressure-molding a sheet-like resin.
The stator coil is formed by winding a round copper wire having an insulating film, and the slot portion of the stator core and the load side coil end portion 46c attached to the load side bracket are wound in completely aligned winding, All intersections of the round copper wires are performed at the anti-load side coil end portion 46d, and the winding start coil end 46a and the winding end coil end 46b of the stator coil are provided at the anti-load side coil end portion 46d.

Further, as shown in the explanatory view after the stator coil is mounted in FIG. 6, the load side coil end portion 46c of the stator coil 46 has an inner peripheral surface and an outer peripheral surface formed on one cylindrical surface, and an end surface thereof. Since the air-core coil is pressure-molded on one conical surface, it is attached in close contact with the load-side bracket via the insulator 47 in a ring shape.
The insulator is a ceramic film processed on the surface of the load side bracket 43, and the load is reduced from the stator coil by setting the minimum thickness to ensure the necessary insulation resistance and withstand voltage between the stator coil and the load side bracket. The heat dissipation to the side bracket is improved.
The stator coil has a gap 46d inside the stator coil where the teeth 45a of the stator core are mounted, and the stator core 45 divided for each tooth is mounted in contact with the insulator 47 from the outside. .
The connection board 52 is connected and attached to the winding start coil end and winding end coil end of the anti-load side coil end of the stator coil shown in FIG.

FIG. 7 is an explanatory diagram of the mounting state of the frame.
In the figure, with the stator core 45 mounted, the heated frame 51 is shrink-fitted and mounted on the stator core.

FIG. 8 is an operation explanatory view for press-molding the outer shape of the stator coil.
In FIG. 2A, the press jig for press-molding the outer shape of the stator coil includes an upper punch 61, a lower punch 62, a die 63 and a core pin 64, and a copper wire is wound around the coil mounting space 63a. As shown in (b), the upper punch is pressed downward to press-mold the outer shape of the stator coil 46.

FIG. 9 is an explanatory view of the pressure molding of the outer shape of the stator coil as viewed from the circumferential direction. In the stator coil 46, the outer shape of the stator coil 46 is pressure-molded except for the end face of the coil end portion on the non-load side. Then, the insulation film is fused by heating to complete the air-core coil.

FIG. 10 is a comparative diagram showing the effect of the present embodiment.
In the figure, in the conventional rotating electrical machine (A) having a cooling water channel in the frame, the average temperature of the stator coil is 130 ° C. when the cooling water temperature of the frame is maintained at 60 ° C. in the rated output state. The stator coil and the insulator are in contact at about 129 ° C., the insulator and the stator core are in contact at about 102 ° C., and the stator core and the frame are in contact at about 72 ° C. Since the heat radiation path of heat is complicated, the average temperature of the stator coil is increased by 70 ° C. with respect to the cooling water temperature of 60 ° C.
If the structure (B) of this embodiment is maintained with the same output and cooling water temperature being the same, the stator coil temperature is reduced to 73 ° C., and the stator coil average temperature is 60 ° C. cooling water temperature. Decreases to 13 ° C rise.
This is because the amount of heat moves more directly from the stator coil to the cooling water of the load side bracket.
Also, as shown in (c), when the amount of heat at 130 ° C., which is the same as that of the stator coil of the conventional structure, is obtained, the generation of heat of 567% can be allowed for (a), and the output is about 2.4 times Can be increased.

As described above, according to the rotating electrical machine of the present embodiment, the heat loss generated in the stator coil is effectively radiated to the cooling water channel, the temperature increase of the stator coil is suppressed, and the allowable temperature is larger. It is possible to provide a rotating electrical machine having a compact water-cooling structure that enables energization and improves the rated output.

The part in which the present invention is different from Patent Documents 1 and 2 is a part in which the bracket has a cooling water channel and a part in close contact with the stator coil via an insulator.

FIG. 11 is an axial cross-sectional view of a rotating electrical machine showing a second embodiment of the present invention.
In the figure, the rotating electrical machine includes a frame 91, a counter load side bracket 84, a stator having a stator coil 86, and a load side bracket 83, and is rotatably supported by the load side bracket and the anti load side bracket. The rotor is not shown. The load-side coil end portion 86a of the stator coil has an inner peripheral surface 86aa and an outer peripheral surface 86ab formed on one cylindrical surface, and an end surface 86ac is pressure-formed on one flat surface. The load-side bracket has a load-side coil end portion and a groove portion 83a of a recess that is in close contact with the inner peripheral surface, outer peripheral surface, and end surface of the load-side coil end portion, and the groove portion has a high heat conductive resin that is an insulator. The load-side coil end part is fixed with a molding resin through the injection molded part.
Having a cooling water channel outside the load side bracket is the same as in the first embodiment.
Since the load-side bracket has a portion that is in close contact with the stator coil via an insulator and has a cooling water channel, the heat amount due to heat loss generated in the stator coil is effectively dissipated to the cooling water channel, and the stator The rated output is improved by suppressing the temperature rise of the coil and enabling larger energization with respect to the allowable temperature.
Other structures are the same as in the first embodiment, such that the stator coil is energized from the outside to the stator coil via a lead wire (not shown).

FIG. 12 is a radial cross-sectional view of the rotating electrical machine.
In the figure, a rotor 71 of a rotating electric machine has an embedded magnet type structure in which a permanent magnet 75 is installed in a rotor core 73 in a V shape for each pole and constitutes a magnetic pole of 10 poles.
The stator is insulated by attaching insulating paper to the teeth 85a of the stator core 85, winding a winding having an insulating coating with distributed winding, and then attaching to the teeth to form a stator coil 86. The inner periphery of the frame 91 is held.

FIG. 13 is an explanatory view showing a pressure forming method of the load side coil end portion.
In the figure, (a) shows a state before molding, and (b) shows a state after molding.
The stator 4 is formed by winding a winding having an insulating coating on the teeth portion of the stator core 84 in a distributed manner, and then mounting the teeth on the teeth portion to form a stator coil 86. Thereafter, the load side coil end portion 86a is With the inner peripheral surface forming jig 92, the outer peripheral surface forming jig 93, and the end surface forming jig 94, the inner peripheral surface 86aa and the outer peripheral surface 86ab are each formed on one cylindrical surface, and the end surface 86ac is formed on one flat surface.

As described above, according to the rotating electrical machine of the present embodiment, the heat loss generated in the stator coil is effectively radiated to the cooling water channel, the temperature increase of the stator coil is suppressed, and the allowable temperature is larger. It is the same as the rotating electrical machine of the first embodiment of the present invention that it is possible to provide a rotating electrical machine having a compact water-cooling structure that enables energization and improves the rated output.

The part in which the present invention is different from Patent Documents 1 and 2 is a part in which the bracket has a cooling water channel and a part in close contact with the stator coil via an insulator.
This embodiment is different from the first embodiment of the present invention in that the air core coil is not mounted, but the winding is mounted on the distributed winding in the slot portion of the stator core.

The rotating electrical machine of the present invention can be applied to a wide variety of industrial rotating electrical machines as well as EV motors because it can provide a rotating electrical machine that suppresses temperature rise and improves the rated output as compared to the conventional one.

1 Frame 2 Stator Core 3 Stator Coil 3a Load Side Coil End 3b Anti Load Side Coil End 4a Load Side Bracket 4b Anti Load Side Bracket 5a Load Side Bearing 5b Anti Load Side Bearing 6 Shaft 7 Rotor 10a High Thermal Conductive Insulator 10b High heat conduction insulator 12 Cooling channel 21 Stator coil 21e Load side coil end 22 Stator core 24 Insulator 25 Load side bracket 25e Load side bracket groove 26 Anti-load side bracket 27 Permanent magnet 28 Rotor core 29 Shaft 31 Rotor 32 Permanent magnet 33 Rotor core 34 Shaft 35 Load side plate 36 Anti load side plate 37 Load side bearing 38 Anti load side bearing 41 Encoder portion 42 Connection portion 43 Load side bracket 43a Inlet tube 43b Lead tube 43c Cooling channel 43d Cooling fin 43e Outside Bolt hole 43f for attachment to the part device Fastening bolt hole 43g with the frame Screw hole 44 for cover attachment Anti-load side bracket 45 Stator core 45 Teeth part 46 Stator coil 46a Winding start coil end 46b Winding end coil end 46c Load side Coil end portion 46d Anti-load side coil end portion 47 Insulator 48 Insulator 48a Outer insulator 48b Inner insulator 48c Insulating tape 49 Dust seal 50 Cover 51 Frame 52 Connection board 53 Outer O-ring 54 Inner O-ring 55 Bolt 61 Upper punch 62 Lower punch 63 Die 63a Coil mounting space 64 Core pin 71 Rotor 73 Rotor core 74 Shaft 75 Permanent magnet 82 Connection portion 83 Load side bracket 83a Groove portion 84 Anti-load side bracket 85 Stator core 85a Ys portion 86 Stator coil 86a Load side coil end portion 86aa Load side coil end portion inner circumferential surface 86ab Load side coil end portion outer circumferential surface 86ac Load side coil end portion end surface 87 Insulator 88 Insulating paper 91 Frame 92 Inner circumference Surface forming jig 93 Peripheral surface forming jig 94 End surface forming jig F Load

Claims

In a rotating electrical machine having a substantially cylindrical rotor that is rotatably supported, a stator, a bracket that supports the stator, and a water cooling structure,
The rotating electrical machine according to claim 1, wherein the bracket includes a cooling water channel and a portion that is in close contact with the stator coil via an insulator.
The rotating electrical machine according to claim 1, wherein the cooling water passage has an opening portion on an outer side of the motor and does not have an opening portion on an inner side of the motor.
2. The rotating electrical machine according to claim 1, wherein the stator coil includes an air-core coil whose outer shape is press-molded and mounted in a slot portion of the stator core.
2. The rotating electrical machine according to claim 1, wherein the stator coil has a coil end portion that is mounted in a distributed winding in a slot portion of a stator iron core and whose outer shape is press-molded.
The rotating electrical machine according to claim 1, wherein the insulator is a ring-shaped molded product and is mounted between the coil end portion and the bracket.
The rotating electrical machine according to claim 1, wherein the insulator is a ceramic film processed on a surface of the bracket.