JPH1051987A - Electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized lightweight electric rotating machine excellent in characteristics. SOLUTION: A ladder type part member 33 of magnetic material wherein a first hole part 33c and a second hole part 33d are formed leaving an edge part 33a and a frame part 33b is used. The second hole part 33d is fitted in the end portion 32b of a tooth part 32 of a stator core 3A, and the ladder type part member 33 is fixed to the inner peripheral surface of the stator core 3A. A tongue part is formed by the frame part 33b, and a half-closed slot system stator is obtained. A stator coil can be accommodated in the slot 31 before the ladder type part member 33 is fixed, so that the stator coil can be accommodated in the previously wound and molded state. As a result, the space factor of a coil can be sufficiently improved, and a small-sized lightweight electric rotating machine can be obtained without deteriorating power factor and efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as an induction motor or a synchronous machine, and more particularly to a rotating electric machine suitable for a relatively small-capacity general-purpose induction motor.

[0002]

2. Description of the Related Art A rotating electric machine such as a general-purpose induction motor having a relatively small capacity has a structure shown in FIG. In FIG. 8, reference numeral 1 denotes a housing, which is also called a frame or a frame.
It constitutes the jacket of the electric motor.

[0003] Reference numeral 1a denotes a radiation fin, which has a strip shape extending in the axial direction, is integrally formed with the housing 1, and is formed radially on the outer periphery thereof. Reference numerals 2A and 2B denote end brackets, which are also called bearing brackets. The bearings 4A and 4B are housed in the housing 1 and are attached to both ends of the housing 1 by spigot fitting.

[0004] Reference numeral 3 denotes a stator, as shown in FIG.
2 having a plurality of slots 31 formed on the inner peripheral side, the stator core 3A being made of a laminate of annular silicon steel sheets (electromagnetic steel sheets), and is provided in the slots 31 of the stator core 3A. It is configured by winding a stator winding 3B.

[0005] Reference numeral 5 denotes a rotor having a rotating shaft 6, which is rotatably held by bearings 4A and 4B of end brackets 2A and 2B, so that the rotating shaft 6 is fixed at a predetermined position in the stator 3. The stator 3 is positioned with an air gap 3C therebetween, and is configured to be rotatable.

In such a conventional motor, the stator 3 is inserted into the housing 1 in advance and attached to the inner peripheral wall thereof, and then the rotor 5 is inserted into the stator 3.
Then, the bearings 4A and 4B are fitted to the rotating shaft 6, and the end brackets 2A and 2B are fitted to both ends of the housing 1 by spigot fitting, respectively.
(Not shown), it is fixedly attached to the housing 1 and assembled.

The rotating shaft 6 has one end (the right side in the figure) inserted through the bearing 4B of the end bracket 2A and protrudes to the outside to form an output shaft, while the other end (the same, left side) is an end. An external cooling fan 9 (hereinafter, referred to as an external fan) is attached to a portion of the bracket 2A protruding from the bearing 4A.

Reference numeral 10 denotes an end cover, which forms a cover for covering the outer fan 9. And this end cover 10
The opening 10a for taking in outside air with the outside fan 9
(Hereinafter referred to as the ventilation inlet). The opposite side of the opening 10a is formed in an open cylindrical shape or an irregular cylindrical shape, so that a radial gap 10b is formed between the end bracket 2A and the outer diameter portion of the housing 1.
Is formed.

Therefore, when the outer fan 9 is rotated by the rotor 5, outside air is sucked in from the ventilation inlet 10a of the end cover 10 and blown out from the gap 10b, whereby the end bracket 2A and the housing 1
And ventilating outside air to the outer surface of the end bracket 2B,
A cooling effect is obtained.

As described above, the rotor 5 is mounted in the housing 1 of the rotating shaft 6 at a position facing the stator 2. The rotor 5 has a secondary conductor bar (not shown) , An end ring 7, and an internal cooling fan 8 (hereinafter referred to as an inner fan) integrally formed with the end ring 7.

The inner fan 8 is composed of a plurality of blades protruding from both end surfaces of the end ring 7 in the axial direction to circulate air inside the electric motor so as to obtain a cooling effect. That is, the air flow generated by the inner fan 8 passes through the rotor 5, the end ring 7, the stator windings 3B, and both end faces of the stator core 3A while being cooled, and is relatively compared with the housing 1. When passing along the inner surfaces of the end brackets 2A and 2B having a low temperature rise, heat can be dissipated.

Incidentally, as a technique relating to this kind of prior art, for example, JP-A-61-251440 can be cited. By the way, in such a rotating electric machine, miniaturization and weight reduction are always great propositions.
Conventionally, a method of forming a housing from a light metal such as aluminum or an aluminum alloy has been known.

That is, when such a rotating electric machine is required to be reduced in size and weight, aluminum or an aluminum alloy material having a small specific gravity and good thermal conductivity (specific gravity is about 1/3 of steel, Using a non-ferrous metal such as a Young's modulus of about 1/3, a specific heat of about 2 times, and a thermal conductivity of about 3 times), the heat generated inside the rotating electric machine can be transmitted to the housing well to cool it. To improve
This makes it possible to reduce the size and weight of the rotating electric machine as well as the weight of the housing itself.

[0014]

However, in the above-mentioned prior art, although a certain effect can be obtained with respect to the weight reduction of the rotating electric machine, sufficient consideration has been given to the improvement of the characteristics accompanying the miniaturization. However, there were the following problems.

First, rotating electric machines tend to have reduced characteristics due to miniaturization, and particularly output and stall torque (maximum torque).
Tends to decrease. However, if the number of windings of the stator coil is increased and the magnetic flux density is increased in order to prevent these reductions, there has been a problem that iron loss increases and power factor and efficiency deteriorate.

Generally, in order to reduce the size of a rotating electric machine,
It is effective to reduce the size of the stator, but in this case, in order to reduce the outer diameter of the stator and output the same torque, the magnetomotive force must be maintained at the same value. That is, it is necessary to configure the rotating electric machine without changing the magnetic load.

In other words, it is important to keep the amount of magnetic flux per unit area of the stator (hereinafter referred to as magnetic flux density) constant without reducing the amount of magnetic flux generated in the stator. However, in this state, the amount of magnetic flux remains the same as before the miniaturization, and only the stator becomes smaller.
This results in an increase in the magnetic flux density, and as a result, a magnetic flux saturation, resulting in deterioration of the characteristics of the rotating electric machine.

Therefore, in order to configure the magnetic load without changing the magnetic load so that the magnetic flux density does not saturate even when the stator becomes smaller, the area of each part of the magnetic path of the stator becomes equal to that before downsizing. Need to be secured. Therefore, as a result, the slot area of the stator is reduced, so that unless the number of the stator windings 3B is reduced, it is impossible to store the stator windings 3B.

This is because in the prior art stator core 3A,
As is clear from FIG. 9, tongue pieces 32 a are provided on both sides of the tip of the tooth part 32, and the entrance of the slot 31 is narrowed. For this reason, in the related art, the stator winding 3B cannot be formed in advance and can be accommodated in the slot 31, and must be formed by inserting one by one from the opening into the slot 31.

As a result, in the slot 31,
The arrangement of the stator windings 3B becomes irregular, so that the storage volume of the coil does not become comparable to the slot volume, and their volume ratio, that is, the space factor, remains in the 60% range, and the coil storage volume This is because there is a limit.

Therefore, in the prior art, when the slot area is reduced as described above for further miniaturization,
Since the storage amount of the coil is reduced and the number of windings is reduced, the magnetic flux density is further increased, causing a problem in characteristics, and there is a problem that miniaturization cannot be promoted.

An object of the present invention is to provide a rotating electric machine which can easily increase the space factor of a stator coil and thereby can be sufficiently miniaturized without deterioration of characteristics. is there.

[0023]

The object of the present invention is to provide a plurality of slots extending radially from the inner peripheral surface by providing a plurality of teeth arranged along the circumferential direction on the inner peripheral surface of the cylinder. In a rotating electric machine having a stator constituted by a stator core having a stator core and a stator winding wound around a slot of the stator core, a tongue piece to be formed at an open end of the slot is It is formed by a member separate from the stator core, and is mounted on the opening end after the stator winding is housed.

As a result, in the stator of the present invention, the stator coil is housed in the slot from the slot opening which is widely opened. Therefore, unlike the related art, it is not necessary to insert the stator coils one by one into the slot, so that a maximum number of stator coil conductors can be accommodated in the slot.

That is, in order to improve the space factor of the coil, the coil may be arranged and stored in the slot.
According to the present invention, the coil can be stored in a state where the opening of the slot is largely opened, so that a number of stator coils are arranged and wound in advance, and without disturbing the aligned state, it is easy to prepare. As a result, the coil space factor in the slot can be maximized, and the area of the slot can be reduced.

According to the present invention, the size of the slot can be reduced, so that the outer diameter of the stator can be reduced and the slot volume can be reduced without changing the magnetic load of the rotating electric machine. Therefore, even if the size and weight are reduced, there is no fear that the power factor or the efficiency is reduced, and a rotating electric machine having good electric characteristics and torque characteristics can be easily obtained.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary electric machine according to the present invention will be described below in detail with reference to the illustrated embodiments. In addition,
The embodiment of the present invention described below is also a case where the present invention is applied to the same general-purpose induction motor as the conventional technology described with reference to FIG. 8, and as a result, the conventional technology of FIG. In particular, since the configuration of the teeth and the slots of the stator core 3A is mainly different, the description of the overall configuration will be omitted in the following description.

FIG. 1 is a partial perspective view of the stator core 3A of the stator 3 according to an embodiment of the present invention as viewed from the inner peripheral surface, and FIG. 2 is a front view of the whole. At
31 is a slot (a groove for accommodating a coil), 32 is a tooth (teeth), 32b is an end of the tooth, 33 is a ladder-like member,
33a is an edge, 33b is a bar, 33c is a first hole, 3
3d indicates a second hole.

The stator core 3A is formed by laminating a predetermined number of magnetic plates such as silicon steel plates in the axial direction. In this embodiment, as shown in the figure, a case is shown in which a magnetic plate divided into four in the circumferential direction by the dividing line 35 is used. .

The stator core 3A is the same as the prior art in that it has a plurality of slots 31 and teeth 32 on the inner peripheral side. There is no tongue piece, and the slot 31 is formed to have substantially the same width from the opening on the inner peripheral side to the bottom on the outer peripheral side, and is opened with the same width on the inner peripheral side.

The ladder member 33, as well as the stator core 3A, those made of a magnetic material such as silicon steel sheets, for example, a strip-shaped plate material having a width dimension W _T, as shown in FIG. 4, the edges A rectangular first hole 33c and a similarly rectangular second hole 33d are formed by punching, leaving the portion 33a and the bar 33b.

First, as shown in FIG. 4, when _WS is the width of the first hole 33c (= width of the second hole 33d) and a is the width of the edge 33a, the dimension W The size of _S is set to be substantially the same as the laminated thickness of the stator core 3A. Therefore, W _T = W _S + 2a.

Next, as also shown in FIG. 4, b is the width of the bar 33b, c is the height of the first hole 33c (the longitudinal direction of the ladder-like member 33, ie, the dimension in the left-right direction in FIG. 4). ), And when d is the height of the second hole 33d, the size of the dimension c is, as shown in FIG.
2 is substantially the same as the width dimension t of the end 32b, while the dimension d is made smaller, so that the dimension (d + 2b), as also shown in FIG.
1 is equal to the width dimension s. As a result,
The ladder-like member 33 as a whole, as shown in FIG.
This means that the ladders are formed at irregular intervals.

Next, the ladder-like member 33 thus formed into a shape as shown in FIG.
After being rounded into a substantially cylindrical shape and inserted into the inner peripheral side of the stator core 3A, the first holes 33c are engaged with the ends 32b of the teeth 32, respectively, as shown in FIGS. As shown in FIG.

As a result, the cross section 33b of the ladder-like member 33
Are located at both ends of the end portion 32b of the tooth portion 32, thereby forming a tongue piece portion having a predetermined width b.
d forms a slot opening located between the tongue pieces in the vicinity of the center of the opening end of each slot 31, thereby forming a so-called semi-closed slot type stator core. Become.

Next, storage of the stator coil in this embodiment will be described with reference to FIG. First, as shown in the middle part of FIG. 6, the stator coil 3 previously wound and formed in accordance with the shape of the slot 31 of the stator core 3A.
Prepare B. Next, these stator coils 3B are put inside the stator core 3A shown in the upper part of FIG.
As shown by arrows from the center side, each stator core 3
A is inserted into the slot 31.

Next, the ladder-like member 33 shown in the lower part of FIG. 6 is inserted into the inner peripheral side of the stator core 3A in a state of being bent in a substantially cylindrical shape. The first hole 33c of the ladder-shaped member 33 is engaged with the tip, and the ladder-like member 33 is mounted on the stator core 3A as indicated by an arrow.

As a result, as shown in FIG. 7, the stator coil 3B is securely housed in the slot 31. At this time, the cross section 33b of the ladder-like member 33
Are located at both ends of the iron core teeth 32, and the narrower hole 33d is located near the center of the open end of the slot 31, as described above. Therefore, as a result, the ladder-like member 3
The third crosspiece 33b functions as a member corresponding to the tongue piece 32a in the prior art shown in FIG.

Therefore, according to this embodiment, it is possible to use a stator coil 3B which has been wound and formed in advance, although it is a stator core of a semi-closed slot type, and as in the prior art, It is not necessary to insert the child coils 3B one by one into the slots, and as a result, the number of conductors of the stator coil 3B can be sufficiently increased.

The reason is that the slot before housing the stator coil has a large opening, so that a number of stator coils 3B are pre-aligned and wound, and the inside of the slot is maintained without breaking the alignment. This is because they can be easily stored.

Moreover, in this embodiment, the stator coil 3B can be inserted into the slot 31 simply by moving from the inner peripheral side to the outer peripheral side of the stator core 3A, and the storage is completed. In comparison with the related art in which the stator coils are inserted one by one into the slots, the stator coils can be stored very easily.

As described above, in order to improve the space factor of the coil, it is sufficient to arrange the coil in the slot and house it. However, according to this embodiment, it is easily obtained, and Even if the volume of the slot is reduced, the occupancy of the coil in the slot can be kept sufficiently high.

In the prior art, since the coil must be introduced into the slot of the stator core and wound and housed, the opening width of the slot is governed by the diameter of one coil. There is a limit to the choice of the opening size between the parts, and this limits the improvement in the characteristics of the rotating electrical machine.

However, according to the embodiment of the present invention, as described above, since the slot is fully opened when the coil is housed, the size of the opening between the tongue pieces may be limited as in the prior art. Therefore, the design tolerance of the rotating electric machine is increased, and the optimum design can be always performed.

Further, according to the above-described embodiment, since the ladder-like member 33 employs a semi-closed slot system, there is no danger that the conductor of the stator coil 3B will come out of the slot 31 to the outside. Since the opening size can be made sufficiently small, the noise generated when the rotor 5 rotates can also be reduced.

[0046]

According to the present invention, the slot opening can be fully opened in spite of the semi-closed slot system, so that the stator coil can be housed only by moving the stator coil. As a result, unlike the related art, it is not necessary to insert the stator coils one by one into the slots, and the space factor of the stator coils in the slots can be increased to the utmost.

As a result, according to the present invention, it is possible to reduce the outer diameter of the stator and to keep the magnetic loading of the rotating electric machine unchanged even when the slot volume is reduced. , There is no danger of power factor or efficiency drop,
It is possible to easily provide a rotating electric machine having good electric characteristics and torque characteristics.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a part of a stator in an embodiment of a rotating electric machine according to the present invention.

FIG. 2 is a front view of a stator in one embodiment of the rotating electric machine according to the present invention.

FIG. 3 is a plan view of a stator core in one embodiment of the rotating electric machine according to the present invention.

FIG. 4 is a plan view of a ladder-like member in one embodiment of the rotating electric machine according to the present invention.

FIG. 5 is a side view of a ladder-like member in one embodiment of the rotating electric machine according to the present invention.

FIG. 6 is an explanatory diagram of a method of housing a stator coil in one embodiment of the rotating electric machine according to the present invention.

FIG. 7 is an explanatory diagram showing a state after the stator coils are housed in one embodiment of the rotating electric machine according to the present invention.

FIG. 8 is a side view in partial cross section showing an example of the rotating electric machine.

FIG. 9 is a front view showing a conventional example of a stator core of a rotating electric machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 1a Radiation fin 2A, 2B End bracket 3 Stator 3A Stator iron core 3B Stator coil 3C Air gap 4A, 4B Bearing 5 Rotor 6 Rotating shaft 7 End ring 8 Inner fan 9 Outer fan 10 End cover 10a Ventilation opening 10b Ventilation Outlet 31 Slot 32 Tooth 32a Tongue 32 of tooth 32 End 32 of tooth 32 Ladder-like member 33a Edge 33b Bar 33c First hole 33d Second hole 35 Back split

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuneo Sekine 4-6-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Izumi Shimizu 4-6-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. In the factory (72) Inventor Matsutoshi Ibara 4-6-1 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Yukio Endo 4-6-Kanda Surugadai, Chiyoda-ku, Tokyo In Hitachi, Ltd. (72) Inventor Kaoru Ogawa 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture, Hitachi, Ltd.Industrial Equipment Division

Claims (2)

[Claims] 1. A stator core having a plurality of slots extending radially from the inner peripheral surface by providing a plurality of teeth arranged in a circumferential direction on an inner peripheral surface of the cylinder; In a rotating electric machine having a stator constituted by a stator winding housed in a slot of a stator core, a tongue piece to be formed at an open end of the slot is separate from the stator core. The rotating electrical machine is formed of the above member, and is mounted on the opening end portion after housing the stator winding. 2. The invention according to claim 1, wherein the separate member is formed by alternately arranging two kinds of rectangular holes having different longitudinal dimensions in a longitudinal direction in a strip-shaped magnetic body. It is made of a member formed in a ladder shape of unequal intervals, and by fitting one of the holes of the member to the plurality of teeth, the portion remaining between the holes of the magnetic body is A rotating electric machine characterized in that a tongue piece is formed.