JPH09261904A - Stator winding of rotating electric machine, stator of rotating electric machine using this winding, and rotating electric machine using this winding - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A rotating electric machine that is easy to assemble and highly reliable can be obtained while sufficiently reducing the size and weight and improving the coil space factor by using a split core type stator. To provide a stator winding of a rotating electric machine. An upper coil portion of a coil end portion 33c
The portion 33cb close to b is located outside the portion 33c close to the lower coil portion 33a of the coil end portion 33c of the other coil 33.
Since ca overlaps, it is formed to have a relatively small bending radius R1, and a portion 33ca close to the lower coil portion 33a of the coil end portion 33c is a portion inside the portion close to the upper coil portion 33b of the coil end portion 33c of another coil 33. Since 33cb overlaps, it has a relatively large bending radius R2. [Effect] Since the shape of the entire coil end portion can be a cylindrical shape that spreads outward, there is no risk of the coil end portion swelling even if the space factor of the coil is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine such as an induction machine or a synchronous machine using a split iron core type stator, and particularly to a stator winding of a rotary electric machine suitable for a general-purpose induction motor having a relatively small capacity. The present invention also relates to a stator of a rotating electric machine using this winding and a rotating electric machine using this winding.

[0002]

2. Description of the Related Art A rotary electric machine having a relatively small capacity, such as a general-purpose induction motor, has a structure shown in FIG. In FIG. 12, reference numeral 1 denotes a housing, which is also called a frame or a frame, and is made into a substantially cylindrical shape by casting an iron-based material such as cast iron, and constitutes an outer casing of the electric motor. Reference numeral 1a denotes a heat radiation fin, which is in the form of a strip extending in the axial direction, is integrally cast with the housing 1, and is radially formed on the outer periphery thereof.

2A and 2B are end brackets, which are also called bearing brackets, in which the bearings 4A and 4B are housed and are fitted to both ends of the housing 1 by spigot fitting.

Reference numeral 3 denotes a stator, as shown in FIG. 13, a stator core 3A made of a laminated body of annular silicon steel plates having a plurality of slots 3C on the inner peripheral side, and a stator core 3A as shown in FIG. It is composed of a stator winding 3B wound in a slot 3C of the child iron core 3A. In FIG. 14, 3D is a slot liner for insulating the stator coil.

A rotor 5 has a rotary shaft 6, and the rotary shaft 6 is rotatably held by bearings 4A and 4B of the end brackets 2A and 2B so that the rotor 3 can be rotated at a predetermined position in the stator 3. , Is configured to rotate at a position facing the stator 3.

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.
A ventilation outlet consisting of 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 rotary electric machine, miniaturization and weight reduction have always been a major proposition, but the miniaturization of the rotary electric machine tends to deteriorate the characteristics, and particularly the output and the stall torque (maximum torque). ) Tends to decrease. However, in order to prevent these decreases, if the number of windings of the stator coil (armature coil) is increased and the magnetic flux density is increased, there is a problem that iron loss increases and power factor and efficiency deteriorate. It was

In general, in order to make a rotary electric machine small,
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 maintain a constant amount of magnetic flux per unit area of the stator (hereinafter referred to as magnetic flux density) without reducing the amount of magnetic flux generated in the stator.

However, in this state, the amount of magnetic flux remains the same as it was before miniaturization, and only the stator becomes smaller, resulting in an increase in magnetic flux density, which in turn causes magnetic flux saturation, resulting in deterioration of the characteristics of the rotating electric machine. Resulting in. Therefore,
Even if the stator becomes smaller, the magnetic flux density does not saturate,
In order to configure without changing the magnetic loading, it is necessary to secure the area of each magnetic path portion of the stator to be equal to that before the miniaturization. As a result, the slot area of the stator is reduced, so that the stator winding 3B is inserted in the slot.
Can no longer be stored.

In the prior art, this is the stator winding 3B.
Had been inserted into the slots 3C one by one from the opening grooves, so that the stator windings 3B were arranged irregularly in the slots 3C as shown in FIG. The storage volume is not comparable to the slot volume, and the volume ratio of these (hereinafter referred to as space factor) is 60
This is because there is a limit to the coil storage, which is limited to the% range.

Therefore, in order to improve the space factor, a method of using a so-called split iron core type stator in which the stator core is divided to improve the coil storability is conventionally known.

As shown in FIG. 4, each of the split core type stator cores has an iron core piece 3 made of laminated electromagnetic steel sheets.
1 and a rod-shaped iron core piece 32 are divided and formed, and a plurality of these are alternately arranged in an annular shape, so that the stator iron core 3A is configured as shown in the figure. .

First, as shown in FIG. 5 (a), the iron core piece 31 includes a back portion 31a, a tooth portion 31b projecting along the centripetal direction at the inner center portion of the back portion 31a, and the tooth portion 31b. Part 3
It is formed in a substantially T shape having notches 31c for forming the slots 3C on both sides in the circumferential direction of 1b.

Further, as shown in FIG. 5 (a), the spine portion 31a of the iron core piece 31 is formed with projections 31d capable of engaging with the rod-shaped iron core piece 32 on both sides, and the projections 31d are formed on both sides of the projection 31d. A chamfer 31e is provided on the upper part on the outer peripheral side.

Next, as shown in FIG. 5B, the rod-shaped core piece 32 has a back portion 32a having the same length as the back portion 31a of the iron core piece 31 and a width similar to that of the tooth portion 31b of the iron core piece 31. Is formed so as to extend straight in the centripetal direction and has a tooth portion 32b provided with a tongue piece 32c protruding in the width direction at the tip.

On both sides of the back portion 32a, the iron core pieces 3 are provided.
A recessed groove 32d that can be engaged with the protrusion 31d of the back portion 31a of No. 1 is formed, and chamfers 32e are formed on both sides of the recessed portion 32d similarly to the iron core piece 31 on the outer peripheral side.
Is provided.

Therefore, by alternately arranging a plurality of iron core pieces 31 and bar-shaped iron core pieces 32 made of these laminated electromagnetic steel plates in a ring shape, as shown in FIG.
A will be formed.

At this time, when the rod-shaped core pieces 32 are inserted outwardly from the center side of the stator core 3A between the core pieces 31, the core pieces 3 are inserted into the recessed grooves 32d of each bar-shaped core piece 32.
The projections 31d of No. 1 are assembled with each other by being engaged with each other, so that the tooth portion 32b of the rod-shaped iron core piece 32 and the tooth portion 31b of the iron core piece 31 form the slot 3C.

Therefore, the back portion 31a of each iron core piece 31
When the rod-shaped iron core piece 32 is inserted and engaged, the plate width in the circumferential direction of the space portion of the slot 3C and the tooth portion 31b adjacent thereto is.
And a space portion of the slot 3C adjacent thereto can be formed.

In the stator core 3A, as shown in FIG. 6, the stator winding 3 is provided in the space of the slot 3C.
The stator winding 3B is formed by applying B, and the stator winding 3B is preassembled from a plurality of individual coils formed in a shape that can be stored in the slot 3C. As shown in FIG. 7, by alternately assembling the iron core pieces 31 and the rod-shaped iron core pieces 32 made of laminated electromagnetic steel plates, as shown in FIG. 6, the stator winding 3B is applied to the stator. It is supposed to get 3.

FIG. 7 is a conceptual diagram for explaining how to assemble the iron core to the coil. Therefore, the shapes of the iron core piece 31 and the rod-shaped iron core piece 32 are shown in FIGS. 4 and 5. It is different from the one.

The method of assembling the stator will be described in more detail with reference to FIG. 7. First, the stator winding 3B including a predetermined number of individual coils 33 formed in advance as described above is used as a jig (not shown). Are held in a ring shape at a predetermined position by means of an iron core piece 31 in advance with respect to the stator winding 3B.
By moving the laminated core piece 310 configured by stacking the
After the stator winding 3B is positioned in the cutout portions 31c on both sides of the tooth portion 31b of the laminated core piece 310, the laminated rod-shaped core piece 320, which is also configured by laminating the rod-shaped core pieces 32 in advance, is used as the stator winding 3B. By moving the laminated core pieces 310 from the inside in the radial direction by moving means (not shown) to insert and engage between the laminated core pieces 310, the tooth portions 31 b of the laminated core pieces 310 and the laminated rod-shaped core pieces 320. The stator winding 3B can be housed in the slot 3C defined by the tooth portion 32b of the.

Next, the structure of the stator winding 3B will be described. As described above, the stator winding 3B is a so-called two-layer superposed winding made up of a plurality of individual coils.
3 is created as follows.

First, as shown in FIG. 8, an insulated conductor wire (magnet wire) is wound into a substantially rectangular shape a predetermined number of times to form an individual coil 33. Next, as shown in FIG. 9, the individual coil 33 is formed by bending so that both sides of the rectangular shape form a lower coil portion 33a and an upper coil portion 33b which are inserted into the slot 3C, and then these upper portions are bent. Coil part 33a
The saddle shape is such that the portions connecting the one end and the other end of the lower coil part 33b and the other end form the coil end parts 33c, 33d located outside from both ends of the stator core 3A. It is bent and formed.

Here, the coil end portions 33c, 3
As shown in FIG. 7, when the stator winding 3B is inserted into the slot 3C of the stator core 3A, the stator core 3d is provided.
The portions are exposed to the outside of A in the axial direction.

On the other hand, the lower coil portions 3a and 33b are the portions to be inserted into the slots 3C as described above, and the slots 3C are arranged radially, so that FIG.
The coil end portions 33c and 33d are bent and formed in the order shown in FIG. 3 and the finished individual coil 33 is formed with a predetermined bending radius R so as to finally form an angle corresponding to the angular position of the slot 3C. Of.

At this time, the lower coil portion 3 of the individual coil 33
a is a portion to be inserted and arranged in the back of the slot 3C,
The upper coil portion 33b is a portion arranged on the inlet side of the slot 3C. Therefore, when the coil end portion 33c is viewed from the inside of the assembled stator 3, it is as shown in FIG.

According to the conventional rotary electric machine using the split core type stator, since it is not necessary to press the stator coil into the slot, it is possible to accommodate many conductors of the stator coil in the slot. In addition, since the stator can be formed by moving each iron core piece, the stator coil can be stored very easily. Further, as a result, the coil space factor can be reliably increased even if the slot area is reduced.

Therefore, according to this conventional technique, the outer diameter of the stator can be reduced, and even if the slot volume is reduced, it is not necessary to change the magnetic load of the rotating electric machine such as reducing the number of turns of the coil. As a result, it is possible to obtain a rotating electric machine having good electric characteristics and torque characteristics without lowering the power factor, efficiency, etc. despite the reduction in size and weight.

[0036]

The prior art described above does not consider the shape of the coil end portion of the stator winding in a rotary electric machine using a split iron core type stator, so that further miniaturization is required. There was a problem in trying.

That is, in the above-mentioned prior art, since the coil space factor can be increased, the outer diameter of the stator can be suppressed, and the size can be reduced. There is no room, the coil end part swells, and the inner diameter becomes smaller than the outer diameter of the rotor, so it becomes impossible to insert the rotor when assembling the rotating electric machine, and the margin with the outer diameter of the rotor decreases. Thus, unless special attention is paid to the assembling, problems such as damage to the coil end portion may occur.

An object of the present invention is to obtain a rotating electric machine which is easy to assemble and has high reliability while sufficiently reducing the size and weight and improving the coil space factor by using the split iron core type stator. It is to provide a stator winding of a rotating electric machine that can be made to operate.

[0039]

In the stator winding of a two-layer lap winding type rotary electric machine, the shape of the coil end portion of each individual coil of this stator winding is set to the upper coil portion side. This is achieved by partially making the lower coil portion side different and making the shape bent to the outer shape side as a whole.

That is, the coil end portion of each individual coil is formed so that when the individual coil is inserted into the slot of the stator core, it is exposed from the end surface of the stator core to one and the other in the axial direction. The sides of the individual coils are shaped to match the angles of slots radially arranged in the stator core.

At this time, a portion of the coil end portion near the coil portion (referred to as an upper coil portion) accommodated on the inlet side of the slot has a small bending radius so that the portion on the inner side of the slot, that is, the bottom portion side. A portion near the housed coil portion (referred to as a lower coil portion) is formed to have a large bending radius.

If the stator winding is constituted by the individual coils thus formed, it is possible to prevent the inner diameter of the coil end portion from becoming smaller than the inner diameter of the stator core. Similarly, since the thickness of the coil end portion, that is, the difference between the inner diameter dimension and the outer dimension dimension can be minimized, it is possible to prevent this portion from coming too close to or in contact with the housing.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION A stator winding of a rotary electric machine according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an individual coil 33 ′ in one embodiment of a stator winding according to the present invention.
3ca represents a portion close to the lower coil portion 33a of the coil end portion 33c, and 33cb represents the coil end portion 33c.
A portion near the upper coil portion 33b is shown.

First, in the individual coil 33 ', the coil end portion 33c is bent in a state where the coil end portion 33c bulges outward as a whole. At this time, as shown in the figure, the bending radius is relatively large in the portion 33ca. In the portion 33cb, a relatively small radius R1 (R2
Bending is performed so that> R1). The other configurations are the same as those of the conventional example described with reference to FIGS. In FIG. 1, one coil end portion 33
Although only c is shown, the other coil end portion 33d is similarly formed with a different bending radius.

Upper coil portion 33b of coil end portion 33c
The portion 33cb close to is close to the lower coil portion 33a of the coil end portion 33c of the other coil 33 on the outside thereof.
Since ca overlaps, it is formed to have a relatively small bending radius R1.

The portion 33ca close to the lower coil portion 33a of the coil end portion 33c has another coil 3 inside.
Since the portion 33cb close to the upper coil portion 33b of the coil end portion 33c of No. 3 overlaps, the bending radius R2 is relatively large.

FIG. 2 is an axial view showing a state where the stator core 3A is assembled to the stator winding 3B formed by using the individual coil 33 '. Here, one coil end portion 33c is provided. Next, FIG. 3 is a view of the coil end portion 33c seen from the inside of the stator core 3A.

And, as is clear from these figures,
First, a portion 33 near the upper coil portion 33b of the coil end portion 33c and having a small bending radius R1.
cb is a coil end portion 3 of another coil 33 on the outside thereof.
The portion 33ca close to the lower coil portion 33a of 3c overlaps.

Next, a portion 33ca, which is near the lower coil portion 33a of the coil end portion 33c and has a large bending radius R2, has inside thereof an upper coil portion 33b of the coil end portion 33c of another coil 33. 33c close to
b will overlap.

Here, the coil end portion 33c of the individual coil 33 '(same for the coil end portion 33d on the opposite side) is, as shown in FIG. 12, from the left and right end surfaces in the axial direction of the stator core 3A. Since it projects, the coil as a whole has a substantially cylindrical shape in this portion.

Therefore, if there is a gap between the coil end portions 33c, there is a risk that the thickness of this cylindrical portion will increase and the inner diameter of this cylindrical portion will become smaller. This happens. In this case, the coil end may be damaged when the rotor 5 is inserted, or the insertion itself may be difficult.

However, first, the coil end portion 33
c is bent so as to bulge outward as a whole, and as a result, all the individual coils 33 ′ are fixed to the stator core 3
In the state of being assembled to A, the coil end portions 33c of the individual coils 33 'are pressed against each other, the entire coil end is formed without a gap, and is opened to the outside as a whole.

Further, according to this individual coil 33 ', since the bending rigidity is high in the portion 33cb of the coil end portion 33c formed with the small bending radius R1, even if the portion 33ca overlaps the outside, the inside portion As a result, the shape opened to the outside as a whole can be reliably maintained.

Therefore, according to this embodiment, there is no fear that the coil end portion swells even if the space factor of the coil is increased, the inner diameter becomes smaller than the outer diameter of the rotor, and the rotor is rotated when the rotating electric machine is assembled. There is no fear that the child can not be inserted, the margin with the outer diameter of the rotor is reduced, and the coil end part may be damaged unless special care is taken during assembly. It is possible to easily obtain a rotating electric machine that is easy to assemble and has high reliability while sufficiently reducing the size and weight and improving the coil space factor by using the stator.

[0055]

According to the present invention, the shape of the entire coil end portion can be made into a cylindrical shape spreading outward by simply changing the shape of the individual coil at the coil end portion. Even if the product ratio is increased, there is no risk of the coil end swelling, and the inner diameter becomes smaller than the outer diameter of the rotor. There is no fear that the coil end will be damaged unless special attention is paid when assembling because the margin is reduced, and the use of a split core type stator reduces the size and weight and the coil space factor. It is possible to easily obtain a rotating electric machine that is easy to assemble and has high reliability while sufficiently improving the above.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an individual coil in a stator winding of a rotating electric machine according to the present invention.

FIG. 2 is an explanatory view of a mounted state showing an embodiment of an individual coil of a stator winding according to the present invention.

FIG. 3 is an explanatory diagram of a coil end portion according to the embodiment of the present invention.

FIG. 4 is an explanatory view of a split iron core type stator core.

FIG. 5 is an exploded explanatory view of a split iron core type stator core.

FIG. 6 is an explanatory view showing a state in which a coil is attached to a split iron core type stator iron core.

FIG. 7 is an explanatory diagram of a method of mounting a coil on a split iron core type stator core.

FIG. 8 is a perspective view of an individual coil before forming.

FIG. 9 is an explanatory view showing an individual coil after molding.

FIG. 10 is an explanatory view of bending and forming an individual coil.

FIG. 11 is an explanatory diagram of a coil end portion.

FIG. 12 is an explanatory diagram showing an example of a rotating electric machine.

FIG. 13 is a plan view showing an example of a stator core.

FIG. 14 is an explanatory diagram of a stator winding in a slot of a stator core.

FIG. 15 is an explanatory diagram of a stator winding by a square wire in a slot of a stator core.

[Description of symbols] 1 housing 3 stator 3A stator iron core 3B stator coil 3C slot 31 iron core piece 32 rod-shaped iron core piece 33 'individual coil 33c coil end portion 33ca coil end portion 33c portion close to lower coil portion 33a 33cb coil Portion near the upper coil portion 33b of the end portion 33c

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tsukio Sekine, 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Izumi Shimizu 4-6-Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. In-house (72) Inventor Yukio Endo 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Matsuri 4--6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Ryuichi Iwata 4-6, Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Takahiro Takeda 7-1 Higashi Narashino, Narashino, Chiba Prefecture Industrial Equipment Division, Hitachi Ltd.

Claims (4)

[Claims] 1. In a stator winding of a two-layer lap winding type rotary electric machine, a shape of a coil end portion of each individual coil of the stator winding is partially changed between an upper coil portion side and a lower coil portion side. Different from each other, and has a shape bent to the outer shape side as a whole, and a portion near the coil portion accommodated on the inlet side of the slot has a smaller bending radius so that the coil portion accommodated on the bottom side of the slot is The stator winding of the rotating electric machine is characterized in that the portion close to is formed to have a large bending radius. 2. The stator winding of a rotating electric machine according to claim 1, wherein each of the individual coils is formed of a conductor having a substantially rectangular cross section. 3. A stator for a rotating electric machine, wherein the stator winding according to claim 1 is used. 4. A rotating electric machine using a stator winding.