JP2004064828A - Stator for rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the processing of the sidewall of a main body tooth and the projection of a mounting tooth in case that the teeth provided separately at the periphery of a yoke consist each of the main body tooth and the mounting tooth , in a stator core. <P>SOLUTION: The stator core 20 consists of an annular yoke 23 and a plurality of teeth 24 for demarcating a plurality of slots 33. Each tooth 24 consists of the main body tooth 25 which includes a pair of sidewalls 27 and a recess 30, and the mounting tooth 40 which includes a base 41 for retaining a stator coil 34 and a projection 45 to be inserted into the recess 30. A gap 50 is made between the tip face 27a of the sidewall 27 and the opposite face 43a of the base 41. By providing it with the gap 50, it will do for the height of the sidewall 27 and the height of the projection 45 to be within a certain tolerance range, and precise finishing processing becomes needless, and the processing becomes easy. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stator of a rotating electric machine, and more particularly to an improvement of a stator core thereof.
[0002]
[Prior art]
One type of rotating electric machine is a generator (alternator). The alternator includes a stator fixed to a frame and a rotating rotor. The stator includes a stator core and a stator coil, and the stator core has an annular yoke, a number of teeth (teeth), and a number of slots. The teeth protrude radially inward from the inner peripheral surface of the yoke and guide magnetic flux from the rotor. The slots are defined by adjacent teeth, in which the stator coils are housed.
[0003]
The stator coil is wound around the slot sequentially from the opening side. The width of the opening of the slot is preferably wider from the viewpoint of facilitating winding of the stator coil. However, from the viewpoint of the formation of the magnetic circuit, the narrower the better, the narrower the advantage is that the gogging torque is reduced. It is difficult to satisfy these two contradictory requirements with known projection-like teeth.
[0004]
In view of this, the applicant of the present application has previously described in Japanese Patent Application Laid-Open No. 2000-50540 (hereinafter referred to as "conventional example") an assembling-type fixing of a rotating electric machine in which teeth are formed by two parts, namely a main body tooth part and a mounting tooth part. Apply for child core.
[0005]
In this conventional example, as shown in FIG. 3, the stator core 70 includes a yoke 72, teeth (teeth) 74 and a slot 79, and the teeth 74 have a base tooth 75 and a separate tooth 80. The base teeth 75 include a pair of side walls 76 formed on the inner peripheral surface of the yoke 72 and a recess 77 between the side walls 76. On the other hand, the separate tooth portion 80 includes a base portion 81 and a convex portion (shaft portion) 82 protruding from the base portion 81. The width of the intermediate portion in the height direction of the convex portion 82, that is, the width C of the intermediate portion in the depth direction of the concave portion 77 is larger than the width in the circumferential direction of the convex portion 82, that is, the width B of the concave portion 77. , Ie, the width A of the bottom surface of the concave portion 77 is smaller than the circumferential width of the front end of the concave portion 77.
[0006]
According to this conventional example, the stator coil (not shown) is stored in the wide slot 79 before the separate tooth portion 80 is attached to the base tooth portion 75, so that the winding is easy. Then, the stator coil wound around the slot 79 is prevented from falling out of the slot 79 by the protruding portion 81a of the base portion 81 of the separate tooth portion 80. Further, since the width A is smaller than the width B, the insertion of the projection 82 into the recess 77 is facilitated. In addition, since the width C is larger than the width B, it is possible to prevent the inserted convex portion 82 from rattling in the concave portion 77 or coming out of the concave portion 77.
[0007]
[Problems to be solved by the invention]
In the above conventional example, the tolerance between the distal end surface 82a of the convex portion 82 of the separate tooth portion 80 and the bottom surface 77a of the concave portion 77 of the base tooth portion 75, and the distal end surface 76a of the side wall portion 76 and the facing surface 81b of the base portion 81 The tolerances between were both zero. Specifically, the height of the side wall 76 and the height of the projection 82 are equal. With this, with the separate tooth portion 80 attached to the base tooth portion 75, the front end surface 82a of the convex portion 82 is brought into contact with the bottom surface 77a of the concave portion 77, and the front end surface 76a of the side wall portion 76 is opposed to the facing surface 81b of the base portion 81. Trying to abut.
[0008]
However, in order to make both of the two tolerances zero, precise finishing must be performed on the side wall portion 76 of the base tooth portion 75 and the convex portion 82 of the base tooth portion 80, which increases the processing cost.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stator of a rotating electric machine in which machining of two portions forming teeth is facilitated and machining cost is low.
[0010]
[Means for Solving the Problems]
The inventor of the present application considered providing a gap between two members constituting the teeth. However, this gap tends to be a magnetic resistance that interrupts a magnetic circuit formed in the teeth of the stator core. Therefore, the present invention was completed by forming a gap having a shape and a size that does not substantially cause magnetic resistance.
[0011]
According to a first aspect of the present invention, there is provided a stator for a rotating electric machine, wherein an annular yoke and a plurality of magnetic flux passages are formed on a circumferential surface of the yoke and are circumferentially spaced from each other. A stator core comprising a plurality of teeth defining slots, wherein each tooth protrudes toward the rotor and includes a pair of side walls and a recess defined by both side walls separated in a circumferential direction. A stator core including a base facing the rotor and protruding from the opening of the slot, and a mounting tooth portion including a protrusion protruding from the base toward the rotor and inserted into the recess; and a stator coil housed in each slot. And consisting of: Further, in the stator according to the first aspect of the invention, a gap is formed between a tip end surface of the side wall portion of each main body tooth portion and an opposing surface of the base portion of the mounting tooth portion, wherein the teeth are formed on the stator core. It is composed of a main body tooth and a mounting tooth separate from the stator core. In this case, the gap can theoretically be provided between the side wall of the main body tooth and the base of the mounting tooth, or between the convex part of the mounting tooth and the recess of the main body tooth. However, considering that the gap becomes a magnetic resistance, not between the bottom surface of the concave portion having a large contact area and the distal end surface of the convex portion, but between the distal end surface of the side wall portion having a small contact area and the opposing surface of the base portion. A gap was formed between them.
[0012]
In this stator, the height of the side wall portion of the main body tooth portion of the stator core has a minus tolerance, and / or the height of the convex portion of the mounting tooth portion has a plus tolerance. The height of the side wall and / or the projection provided with the tolerance can be loosely controlled.
[0013]
According to a second aspect of the present invention, there is provided a stator according to the seventh aspect, wherein an annular yoke and a plurality of circumferentially spaced magnetic flux paths are formed on a peripheral surface of the yoke to define a plurality of slots. The yoke has a holding portion including a pair of side walls protruding toward the rotor and a recessed section defined by a pair of side walls and both side walls, and the teeth are provided on the rotor. The stator core includes a base protruding from the base and facing the opening of the slot, and protruding from the base toward the rotor side and inserted into the recess; and a stator coil housed in the slot. Further, a gap is formed between the distal end surface of the side wall portion of each holding portion and the opposing surface of the tooth base.
[0014]
In the stator according to the second aspect, the holding portion is formed on the stator core, and the teeth separate from the stator core are held by the holding portion. Also in this stator, the height of the side wall of the holding portion of the stator core is given a minus tolerance, and / or the height of the teeth projection is given a plus tolerance. The height of the side wall and / or the projection provided with the tolerance can be loosely controlled.
[0015]
The gaps of the first and second inventions facilitate the processing of the mounting teeth or the holding part and the main body teeth or the teeth, and are intentionally provided so as to minimize magnetic resistance. It should be distinguished from gaps that happen to be convenient.
[0016]
According to a second or eighth aspect of the present invention, in the first or seventh aspect, the distal end surface of the mounting tooth portion or the convex portion of the tooth is in contact with the bottom surface of the main body tooth portion or the concave portion of the holding portion.
[0017]
According to a third or ninth aspect of the present invention, in the second or eighth aspect, the area of the distal end surface of each of the side walls is much smaller than the area of the distal end surface of the convex portion.
[0018]
According to a fourth or tenth aspect of the present invention, in the third or ninth aspect, the width of each side wall is from 1/10 to 1/3 of the width of the recess, and the height of the gap is from 1/100 of the width of the side wall. 1/5.
[0019]
According to a fifth or eleventh aspect of the present invention, in the first or seventh aspect, the concave portion of the main body tooth portion or the holding portion gradually increases in width as the depth increases, becomes maximum near the center, and then gradually decreases. The convex portion of the teeth gradually increases in width as the height increases, reaches a maximum near the center, and then gradually decreases.
[0020]
In the stator according to claim 6 or claim 12, in claim 1 or 7, the mounting tooth portion or the base of the tooth includes a central portion, a pair of opposed portions on both outer sides of the central portion, and a pair of extended portions on both outer sides of the opposed portion. Including, the opposing portion opposes the side wall portion, and the overhang portion projects over the opening of the slot.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
<Rotating electric machine>
The rotating electric machine includes a motor, a generator and a motor / generator. Among them, for example, a synchronous motor flows an alternating current through a coil of a stator to form a rotating magnetic field, and attracts or repels a rotor as a fixed magnetic pole to rotate. Further, for example, a three-phase AC generator generates electric power in a coil of a stator by rotating magnetic flux of a rotor.
[0022]
The motor / generator has the functions of both a motor and a generator. When the power supply (battery) has a small amount of charge, it functions as a generator and charges the generated electric power to the battery. When in use, it functions as a motor and assists the driving force of the engine.
<Stator>
The stator includes a stator core and a stator coil. The stator core includes an annular yoke and a plurality of teeth circumferentially spaced on an inner or outer peripheral surface thereof. In the first invention, each tooth includes a main body tooth formed on the stator core and a mounting tooth separate from the stator core. On the other hand, in the second aspect, the holding portion is formed on the stator core, and the teeth separate from the stator core are held by the holding portion.
[0023]
In both the first invention and the second invention, a stator coil is housed in a slot defined by adjacent teeth and wound around using the teeth. For example, in the case of a three-phase AC generator, three stator coils are wound.
<Main body teeth, holding part>
The main body tooth portion in the first invention, that is, the holding portion in the second invention, includes a pair of side wall portions and a concave portion formed between both side wall portions. The pair of side walls protrude inward from the inner peripheral surface of the yoke or outward from the outer peripheral surface, are circumferentially spaced, and have a symmetrical shape. The cross-sectional shape is an elongated rectangular shape, and the width may be uniform over the entire height, or may gradually increase toward the base. The thickness (axial dimension of the stator core) is the same as the thickness of the yoke.
[0024]
The distance between the side walls, that is, the width of the concave portion is determined by the shape of the inner surface of the side wall, and may be uniform over the entire depth, but gradually decreases as the depth increases or gradually increases to near the center of the depth. It is desirable that it gradually decreases thereafter. The depth of the recess is determined by the height of the side wall.
<Mounting teeth, teeth>
The attachment tooth portion in the first invention, that is, the tooth in the second invention, includes a base portion and a protruding portion protruding from the base portion, and can have a T-shaped cross section. The base has a rectangular shape curved outward or inward and faces the rotor, and one side (circumferential side) corresponds to the pitch of the slot, and the other side corresponds to the thickness of the yoke. The base can have a central portion, a pair of opposing portions located on both outer sides thereof and facing the side wall portion, and a projecting portion located on both outer sides and projecting to the opening of the slot.
[0025]
The projection protrudes from the center of the base in a direction opposite to the direction of curvature of the base. The height of the protrusion is higher than the height of the side wall, and the width and length correspond to those of the concave portion of the main body tooth portion or the holding portion. Accordingly, the width may be uniform, but it is desirable that the width gradually decreases toward the tip or gradually increases to near the center of the depth and then gradually decreases. When the mounting tooth or the tooth is fitted to the main body tooth or the holding part, the tip of the projection comes into contact with the bottom of the recess.
<Gap>
It is desirable to form a gap between the front end surfaces of both side wall portions and the two opposing surfaces of the base portion opposed thereto, but a gap may be formed only between one of the front end surfaces and the opposing surface. In order to form the gap, specifically, a negative tolerance may be provided for the height of the side wall portion, or a positive tolerance may be provided for the height of the convex portion. If a tolerance is provided for both, the processing of the side wall and the projection is facilitated. If a tolerance is provided for only one of the side, the processing of the side wall and the projection is facilitated. Further, the height of the side wall portion and the height of the convex portion may not be provided with a tolerance, and a recess may be formed on the facing surface of the base portion.
[0026]
The size of the gap is, for example, the width of the tip of the side wall is about 1/10 to 1/3 of the width of the opening of the recess, and the height of the gap is about 1/100 to 1/5 of the width of the side wall. be able to.
[0027]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, the rotating electric machine is a three-phase AC generator, and the teeth are composed of main body teeth and mounting teeth.
(Constitution)
In FIG. 1, the generator includes a rotor 10, a stator 20, and the like. The rotor 10 includes a shaft (not shown) rotatably supported by a frame (not shown), a rotor core 11 attached to the shaft, S-pole and N-pole magnets 13 housed in a space 12 of the rotor core 11, and the like.
[0028]
On the other hand, the stator 20 has a cylindrical shape as a whole, is mounted on the frame, and houses the rotor 10 in its internal space. The stator 20 is roughly divided into a stator core 22 and a stator coil 34.
[0029]
The stator core 22 is formed by laminating a number of thin iron plates, and includes an annular yoke 23 and a number of teeth (teeth) 24. More specifically, the teeth 24 formed on the inner peripheral surface of the yoke 23 include main body teeth 25 and mounting teeth 40.
[0030]
2, the main body teeth 25 include a pair of side walls 27 protruding inward in the radial direction. The inner side surface of each side wall 27 is composed of an opening-side vertical surface 28a having a gradually decreasing width and a rear-side inclined surface 28b having a gradually increasing width. The outer surface 29 extends parallel to the radius. The height has a negative tolerance. The width of the concave portion 30 formed between the pair of side wall portions 27 increases at a constant rate from the entrance side, becomes maximum near the center, and decreases at a constant rate on the back side.
[0031]
A slot 33 is defined by the adjacent teeth 24 (more precisely, the side wall 27) and has a rectangular cross section. The width of the slot 33 is greater than the width of the recess 30, and the depth is greater than the depth of the recess 30. A stator coil 34 is housed in the slot 33 and wound around the teeth 24.
[0032]
The base 41 of the mounting tooth portion 40 has a generally outwardly curved rectangular plate shape, with one side substantially equal to the circumferential pitch of the adjacent slot 33 and the other side equal to the thickness of the yoke 23. The base 41 has a central portion 42, a pair of opposing portions 43 on both outer sides thereof, and a projecting portion 44 on both outer sides thereof. A convex portion 45 protrudes from the central portion 42 in a direction opposite to the bending direction of the base portion 41, that is, in a radially outward direction. The opposing surface 43 a of the opposing portion 43 opposes the tip end surface 27 a of the side wall portion 27, and the projecting portion 44 projects over the opening of the slot 33.
[0033]
The width and length of the protrusion 45 correspond to those of the recess 30 of the main body tooth 25. The height has a plus tolerance, and is slightly higher than the height of the side wall 27. As a result, in a state where the distal end surface 45a of the convex portion 45 is in contact with the bottom surface 30a of the concave portion 30, the distal end surface 27a of the side wall portion 27 does not contact the opposing surface 43a, and a gap 50 is formed between the two. I have.
[0034]
When the stator coil 34 is wound around the stator core 22, the film-shaped insulators 46 are arranged on the bottom surface and both side surfaces of the slot 33 before the mounting teeth 40 are fitted to the main body teeth 25. In this state, the stator coil 34 is housed in the slot 33, and both ends of the insulator 46 are overlapped on the opening side. Next, the convex portion 45 of the mounting tooth portion 40 is fitted into the concave portion 30 of the main body tooth portion 25, and inserted until the distal end surface 45 a of the convex portion 45 contacts the bottom portion 30 a of the concave portion 30. Since the width of the convex portion 45 and the concave portion 30 gradually increases halfway and then gradually decreases, there is no concern that the once inserted mounting tooth portion 40 comes off from the main body tooth portion 25.
(Effect)
During operation of the three-phase alternator, magnetic flux from the N-pole magnet 13 of the rotor 10 travels through the air gap in the stator core 22 and returns to the S-pole. When the rotor 10 is rotated by an engine or the like, the magnetic flux flowing in the stator core 22 rotates and moves, and the magnetic flux of the rotor 10 is linked by the stator coil 34, and the three-phase electromotive force is applied to the stator coil 34. Occurs.
[0035]
According to the present embodiment, first, the machining of the side walls 27 of the main body teeth 25 and the projections 45 of the mounting teeth 40 constituting the teeth 24 of the stator core 22 is facilitated. That is, the height of the side wall portion 27 is determined using the bottom surface 30a as a reference surface, and a negative tolerance is given to the height. Therefore, the height of the side wall portion 27 does not need to be a specific size as in the conventional example, but may be within the range of the minus tolerance, and the machining is facilitated accordingly. On the other hand, the height of the convex portion 45 is determined using the tip surface 45a as a reference surface, and a plus tolerance is given to the height. Therefore, the height of the convex portion 45 does not need to be a specific value, and may be within the range of the plus tolerance, which facilitates processing.
[0036]
Second, the gap 50 between the side wall portion 27 and the facing portion 43 hardly increases the magnetic resistance of the stator core 22 while the first effect is obtained. That is, when the rotor 10 rotates, the magnetic flux is formed in the teeth 24 of the stator core 22 in the direction indicated by the arrow X in FIG. 1, and the gap 50 between the side wall portion 27 and the facing portion 43 is a direction intersecting the gap. However, the width of the side wall 27 is small, and the thickness (height) of the gap 50 is very small. Therefore, the increase in magnetic resistance due to the formation of the gap 50 does not substantially matter.
[0037]
【The invention's effect】
As described above, according to the stator of the first aspect of the present invention, since the gap is formed, the height of the side wall portion of the main body tooth portion and / or the convex portion of the mounting tooth portion are formed. The height management becomes loose. As a result, the processing of the side wall and / or the projection, and hence the processing of the body teeth and the mounting teeth, becomes easy. Moreover, since the gap has a small width, length and height, it does not substantially become a magnetic resistance.
[0038]
According to the stators of the second, third and fourth aspects, since there is no gap between the tip surface of the convex portion having a large area and the bottom surface of the concave portion, the magnetic resistance does not increase in this portion.
[0039]
According to the stator of the fifth aspect, the mounting teeth are prevented from coming off by the main body teeth. According to the stator of the sixth aspect, a gap is secured between the main body teeth and the mounting teeth, and the mounting teeth prevent the stator coil from falling off.
[0040]
According to the stator of the second aspect of the present invention, since the gap is formed, the height of the side wall portion of the holding portion and / or the height of the tooth convex portion is moderately managed. Become. As a result, the processing of the side wall portion and / or the convex portion, and further, the processing of the holding portion and the teeth are facilitated. Moreover, since the gap has a small width, length and height, it does not substantially become a magnetic resistance.
[0041]
According to the eighth, ninth, and tenth aspects of the present invention, since there is no gap between the tip surface of the convex portion having a large area and the bottom surface of the concave portion, the magnetic resistance does not increase in this portion.
[0042]
According to the stator of the eleventh aspect, the escape of the teeth is prevented by the holding portion. According to the stator of the twelfth aspect, a gap is secured between the holding portion and the teeth, and the teeth prevent the stator coil from falling off.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a stator core of a rotating electric machine according to the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is a cross-sectional view of a main part of a conventional stator core.
[Explanation of symbols]
10: Rotor 20: Stator 22: Stator core 23: Yoke 24: Teeth 25: Body tooth part 30: Concave part 40: Mounting tooth part 45: Convex part 50: Clearance

Claims (12)

A stator core comprising: an annular yoke; and a plurality of teeth circumferentially spaced around a circumferential surface of the yoke to form a magnetic flux path and partition a plurality of slots, each of the teeth facing a rotor. A main body tooth portion including a pair of side walls protruding and circumferentially spaced apart from each other and a concave portion defined by the side wall portions; a base facing the rotor and projecting into an opening of the slot; A stator core including:
And a stator coil housed in each of the slots.
A stator for a rotating electric machine, wherein a gap is formed between a distal end surface of the side wall portion of each main body tooth portion and an opposing surface of a base portion of the mounting tooth portion. The stator according to claim 1, wherein a tip end surface of the convex portion of the mounting tooth portion is in contact with a bottom surface of the concave portion of the main body tooth portion. 3. The stator according to claim 2, wherein the area of the front end surface of each of the side wall portions is smaller than the area of the front end surface of the convex portion. The stator according to claim 3, wherein the width of each of the side wall portions is 1/10 to 1/3 of the width of the concave portion, and the height of the gap is 1/100 to 1/5 of the width of the side wall portion. . The concave portion of the main body tooth portion gradually increases in width as the depth increases and becomes maximum near the center and then gradually decreases, and the convex portion of the mounting tooth portion gradually increases in width as the height increases and becomes maximum near the center. 2. The stator according to claim 1, wherein the stator gradually decreases after the following condition. The base of the mounting tooth portion includes a central portion, a pair of opposing portions on both outer sides of the central portion, and a pair of projecting portions on both outer sides of the opposing portion, each of the opposing portions facing each of the side wall portions, The stator according to claim 1, wherein the overhang portions prevent the stator coil from falling off. A stator core comprising: an annular yoke; and a plurality of teeth circumferentially spaced on a circumferential surface of the yoke to form a magnetic flux path and define a plurality of slots, the yoke projecting toward the rotor. It has a pair of side walls spaced apart in the circumferential direction and a holding portion including a concave portion defined by the side walls, and the teeth are opposed to the rotor and extend from the base protruding from the opening of the slot. A stator core including a protrusion protruding to the opposite rotor side and inserted into the recess;
And a stator coil housed in each of the slots.
A stator for a rotating electrical machine, wherein a gap is formed between a tip end surface of the side wall portion of each of the holding portions and an opposing surface of a base portion of the teeth. The stator according to claim 7, wherein a tip end surface of the convex portion of the tooth is in contact with a bottom surface of the concave portion of the holding portion. 9. The stator according to claim 8, wherein the area of the front end surface of each of the side wall portions is smaller than the area of the front end surface of the convex portion. The stator according to claim 9, wherein the width of each of the side walls is 1/10 to 1/3 of the width of the recess, and the height of the gap is 1/100 to 1/5 of the width of the side walls. . The concave portion of the holding portion gradually increased in width as the depth increased and reached a maximum near the center, and then gradually decreased.The convex portion of the tooth gradually increased in width as the height increased and became maximum near the center. The stator according to claim 7, wherein the stator gradually decreases thereafter. The base of the tooth includes a central portion, a pair of opposed portions on both outer sides of the central portion, and a pair of overhang portions on both outer sides of the opposed portion, each of the opposed portions facing each of the side wall portions, The stator according to claim 7, wherein the overhang portion prevents the stator coil from falling off.

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