JPH11122888A - Stator of electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator wherein permanent magnets are held on a magnet holder by proper interference fit without causing core stop. SOLUTION: A synthetic resin magnet holder 3 contained in the stator comprises two ring sections 37 which clamp two permanent magnets, fixed along the inner circumferential surface of a yoke, from both sides in the axial direction, and two coupling sections 36 which are placed so that the specified gap between the permanent magnets is filled and couples together both the ring sections 37. The coupling sections 36 of the magnet holder 3 are provided with a lightening hole 31 formed in the radial direction and a plurality of projections 362 with their back facing the lightening hole 31 and opposite to the permanent magnets. The projections 362 act to hold the permanent magnets on the magnet holder 3 by an interference fit with some allowed degree of dimensional errors, due to the deformation in the projections 362 themselves and the frame section 32 around the lightening-hole 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a rotating electric machine, and more particularly to the technical field of a stator using a permanent magnet as a field magnet.

[0002]

2. Description of the Related Art As prior art, Japanese Patent Publication No. 1-2316
There is a stator for a rotating electric machine disclosed in Japanese Patent Publication No. 46-46.
The stator includes two ring portions for holding a plurality of permanent magnets, and a plurality of connecting portions arranged between the permanent magnets and connecting the ring portions to each other. A magnet holder made of synthetic resin that is held in contact with the inner peripheral surface is used. The distance between the two ring portions of this magnet holder is designed to be slightly shorter than the length of each permanent magnet in the axial direction, and this magnet holder is fitted with each permanent magnet between the two ring portions by interference fitting. Hold.

[0003]

However, a dimensional error occurs between the length of each permanent magnet actually manufactured and the interval between the two ring portions of the magnet holder. In order to keep the dimensional tolerance within the above range, it is necessary to manufacture the device precisely, which leads to an increase in cost. Conversely, if a large dimensional tolerance is set so as not to cause an increase in cost, the permanent magnet will not be held firmly with respect to the magnet holder, or conversely, excessive deformation or concentrated stress will occur in the magnet holder, causing a problem from the corner. It is inconvenient because of cracks.

Accordingly, an object of the present invention is to provide a stator for a rotating electric machine in which each permanent magnet is held by a magnet holder with a proper interference fit without substantially increasing the cost.

[0005]

Means for Solving the Problems and Their Functions / Effects To solve the above problems, the inventor has invented the following means. (First Means) A first means of the present invention is a stator for a rotating electric machine according to claim 1. In this means, a lightening hole is formed in at least one of the connecting portion and the ring portion of the magnet holder. A plurality of projections projecting from the permanent magnet are formed on the one side, and at least a part of these projections is formed to project backward from the lightening hole.

Therefore, when the permanent magnet is fitted into the magnet holder, the magnet holder abuts on the end face of the permanent magnet near the apex of the projection, so that even if there is some dimensional error in the permanent magnet and the magnet holder, The permanent magnet is held in the magnet holder with a proper interference fit by the elastic deformation of the projection. further,
The protrusion protruding backward from the lightening hole is added to the elastic deformation of the protrusion itself and the reduction in rigidity due to the lightening hole, so that elastic deformation can be obtained in a larger range and the permanent magnet can be properly adjusted. It can be held on the magnet holder by an interference fit.

When a plurality of projections are formed on the connecting portion of the magnet holder, the interval between the two ring portions of the magnet holder is designed to have a dimensional tolerance such that the permanent magnet is slightly loosely fitted. And good. Similarly, when a plurality of protrusions are formed on the ring portion of the magnet holder, it is preferable to design the dimensional tolerance of the connecting portions of the magnet holder so that the permanent magnet is slightly loosely fitted. Alternatively, when protrusions are formed on both the connecting portion and the ring portion of the magnet holder, each of the protrusions is elastically deformed so that the permanent magnet is held. It is good to design the tolerance.

It is to be noted that providing a projection and a lightening hole in a magnet holder made of a synthetic resin requires a slight increase in the cost of the mold. Therefore, in the case of mass production, the cost is hardly increased by this means. Therefore, according to this means, there is an effect that it is possible to provide a stator of a rotating electric machine in which each permanent magnet is held by the magnet holder with a proper interference fit, without substantially increasing the cost.

(Second Means) A second means of the present invention is a stator for a rotating electric machine according to claim 2. In this means, at least half of the connecting portions of the magnet holder are at least one lightening hole formed in the radial direction, a solid portion without the lightening hole, and a projection facing the solid portion, And a projection facing the lightening hole. The protrusion height of the projection facing the lightening hole is higher than the projection height of the projection facing the solid portion by an appropriate amount.

[0010] Therefore, the projection facing the lightening hole can be deformed with a larger stroke than the projection facing the solid portion due to the deformation near the lightening hole in addition to the deformation of the projection. Large dimensional tolerances can be set. In other words, even if the dimensional error of the permanent magnet and the magnet holder becomes large to some extent, each permanent magnet is held by the magnet holder by a large deformation stroke of the projection facing the lightening hole.

Therefore, according to this means, in addition to the effect of the above-mentioned first means, the permanent magnet and the magnet holder can be designed with a wider dimensional tolerance, which has the effect of reducing costs. (Third Means) A third means of the present invention is a stator for a rotating electric machine according to claim 3.

According to this means, at least one of the two ring portions of the magnet holder has at least one lightening hole, a solid portion having no lightening hole, a projection facing the solid portion,
And a projection facing the lightening hole. The protrusion height of the projection facing the lightening hole is higher than the projection height of the projection facing the solid portion by an appropriate amount. Therefore, the projection facing the lightening hole can be deformed with a larger stroke than the projection facing the solid portion due to the deformation near the lightening hole in addition to the deformation of the projection, and a larger dimensional tolerance Can be set. In other words, even if the dimensional error of the permanent magnet and the magnet holder becomes large to some extent, each permanent magnet is held by the magnet holder by a large deformation stroke of the projection facing the lightening hole.

Therefore, according to this means, in addition to the effect of the above-mentioned first means, the permanent magnet and the magnet holder can be designed with a wider dimensional tolerance, which has the effect of reducing costs. (Fourth Means) A fourth means of the present invention is a stator for a rotating electric machine according to claim 4.

The present means will be described by taking a four-pole stator as an example. In this means, there are four permanent magnets and four connecting portions of the magnet holder at every 90 ° around the rotation axis. Of these four connecting portions, two opposing connecting portions are formed with lightening holes, but the other two opposing connecting portions are not formed with lightening holes. Therefore, when forming the magnet holder of the present means by injection molding of synthetic resin,
The female mold for forming the outer peripheral surface of the magnet holder can be divided into two parts.

That is, when the lightening holes are formed in all four connecting portions in the radial direction, at least four female dies for forming the outer peripheral surface of the magnet holder are required. This means requires only two female molds. Therefore, according to this means, it is possible to reduce the manufacturing cost of the magnet holder. Therefore, according to this means, the first
In addition to the effect of the means, there is an effect that, for example, a quadrupole stator can be provided at lower cost.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the stator of the rotating electric machine according to the present invention will be clearly and fully described in the following embodiments so that those skilled in the art can understand the present invention. Embodiment 1 (Structure of Embodiment 1) As shown in FIG. 1, a stator of a rotating electric machine according to Embodiment 1 of the present invention has a substantially hollow cylindrical yoke 1 made of soft magnetic mild steel, and a yoke. Two permanent magnets 2 fixed along the inner peripheral surface of the first permanent magnet at predetermined intervals in the circumferential direction
And a magnet holder 3. The magnet holder 3 is an integrally molded member made of a synthetic resin, and fills a predetermined space between the two permanent magnets 2 and two ring portions 37 that sandwich the two permanent magnets 2 from both ends in the axial direction. And two connecting portions 36 arranged to connect the two ring portions 37 to each other. Then, the magnet holder 3 connects the two permanent magnets 2 to the respective connecting portions 36.
And is held in contact with the inner peripheral surface of the yoke 1.

One end (the right end in the figure) of the yoke 1 constitutes a rear cap, and a bearing 11 is held at the center of the rear cap. On the other hand, the other end (left end in the figure) of the yoke 1 forms an open end, and a front cap 6 is joined to the open end by screwing. A bearing 61 is held at the center of the front cap 6, and the coaxial bearing 61 and the bearing 11 rotatably support the rotor 5 having an armature.

As shown in FIG. 2, a holding cylinder 4, which is a thin cylindrical member made of non-magnetic stainless steel, is inserted in contact with the inner peripheral surfaces of the permanent magnet 2 and the magnet holder 3 (FIG. 2). 1 is omitted). The holding cylinder 4 has an effect of preventing a part or a piece of the permanent magnet 2 from coming into contact with the rotor 5 even when the permanent magnet 2 is broken due to an excessive impact or the like. The holding cylinder 4 is not an essential member and may be omitted in a small rotating electric machine or the like.

As shown in FIGS. 2 and 3, the connecting portion 36 of the magnet holder 3 is formed with two oblong lightening holes 31 arranged in series and penetrating in the radial direction. The magnet holder 3 has protrusions 361 and 362 that protrude from the connecting portion 36 so as to face the circumferential end surfaces of the respective permanent magnets 2. Some of the protrusions 362 face the lightening holes 31 and protrude from the frame portions 32 of the lightening holes 31 so as to face the respective permanent magnets 2. On the other hand, the other protrusion 361 protrudes rearward from the solid portion 33 of the connecting portion 36 having no lightening hole 31 to the solid portion 33.

As shown in FIG. 4, the protrusion height of the protrusion 362 facing the lightening hole 31 is larger than the protrusion height of the protrusion 361 facing the solid portion 33 without the lightening hole 31.
Slightly higher by Δh. Therefore, as shown in FIG.
In a state where the permanent magnet 2 is held, the frame portion 32 around the lightening hole 31 is deformed, and the protrusion 362 is pressed against the circumferential end face 21 of the permanent magnet 2 with a longer stroke. At the same time, the protrusion 361 and the protrusion 362 are compressed and deformed in the protruding direction, and press the circumferential end surface 21 of the permanent magnet 2 to hold the permanent magnet 2.

The spacing between the two ring portions 37 of the magnet holder 3 (see FIG. 3) is designed to have a dimensional tolerance such that each permanent magnet 2 is slightly loosely fitted. (Operation and Effect of First Embodiment) Since the stator of the rotating electric machine of the present embodiment is configured as described above, the following two operation and effects are exhibited.

First, each of the permanent magnets 2 is properly fitted with an appropriate interference fit.
Is held by the magnet holder 3. This is because the magnet holder 3 comes into contact with the end face 21 of each permanent magnet 2 near the apex of each of the deformable protrusions 361 and 362, so that even if there is some dimensional error in each permanent magnet 2 and the magnet holder 3, it is allowable. Is done. That is, even if there is a slight dimensional error, each permanent magnet 2 is held by the magnet holder 3 by a proper interference fit by the elastic deformation of the protrusions 361 and 362.

The protrusions 3 are provided on the magnet holder 2 made of synthetic resin.
The provision of the holes 61 and 362 and the lightening holes 31 requires a slight increase in the cost of the molding die. therefore,
In the case of mass production, the stator of this embodiment hardly causes an increase in cost. Therefore, according to the stator of the rotating electric machine of the present embodiment, there is an effect that each permanent magnet 2 is held by the magnet holder 3 with a proper interference fit without substantially increasing the cost.

Second, there is a cost reduction effect. This is because each connecting portion 36 of the magnet holder 3 is opposed to the two lightening holes 31 formed in the radial direction, the solid portions 33 and 35 without the lightening holes 31, and the solid portions 33. Protrusion 3
61, and a projection 362 facing the lightening hole 31. The protrusion height of the protrusion 362 facing the lightening hole 31 is higher than the protrusion height of the protrusion 361 facing the solid portion 33 by an appropriate amount Δh (see FIG. 4).

Therefore, the projections 3 facing the lightening holes 31
62 can be deformed with a larger stroke than the protrusion 361 facing the solid portion 33 by deformation of the frame portion 32 around the lightening hole 362 in addition to deformation of the protrusion 362 (see FIG. 5). Larger dimensional tolerances can be set. In other words, even if the dimensional error between the permanent magnet 2 and the magnet holder 3 becomes large to some extent, the large deformation stroke of the projection 362 facing the lightening hole 31 causes each permanent magnet 2 to be held in the magnet holder 3 by tight fitting. Is done.

Therefore, according to the stator of the rotating electric machine of the present embodiment, the permanent magnet 2 and the magnet holder 3 can be designed with a large dimensional tolerance, which leads to an effect of reducing costs. (Modification 1 of Embodiment 1) As a modification 1 of this embodiment, as shown in FIG.
It is possible to implement a stator of a rotating electric machine employing a magnet holder 3 ′ in which projections 371 protruding from both front and rear end surfaces are formed.

In this modified embodiment, the dimensional tolerance is set so that the front ends of the protrusions 371 of both ring portions 37 ′ and the front and rear end surfaces of the permanent magnet 2 are tightly fitted. therefore,
Since the dimensional tolerance between the front-rear direction of the permanent magnet 2 and the two ring portions 37 'is large within the range of deformation of the projections 371 of the both ring portions 37', processing accuracy is not required and cost is reduced. In addition, since each permanent magnet 2 is held by the magnet holder 3 'not only with each connecting portion 36 of the magnet holder 3' but also with both ring portions 37 'by interference fit, there is no backlash and the vibration environment can be used. However, there is an effect that there is little fear of wear.

[Second Embodiment] A stator of a rotating electric machine according to a second embodiment is a four-pole stator. As shown in FIG. 7, the connecting portion 3 is provided on the magnet holder 3 'of the stator of this embodiment.
6 'and 36 "are provided at every 90 [deg.] Around the rotation axis. Of these four connecting portions 36' and 36", two opposing connecting portions 36 'are provided with a lightening hole 31 and a projection 36.
3 are formed, but the other two opposite connecting portions 3 are formed.
No lightening hole and no projection are formed in 6 ". Therefore, when the magnet holder 3 'of this embodiment is formed by injection molding of synthetic resin, the outer peripheral surface of the magnet holder 3' is formed. Female mold M can be divided in two.

That is, four connecting portions 36 ', 3
Assuming that the lightening holes 31 are formed in the radial direction in all 6 ″, at least four female dies M for forming the outer peripheral surface of the magnet holder 3 ′ are required. In the present embodiment, only two female dies M are required, and therefore, according to the present embodiment, the manufacturing cost of the magnet holder can be reduced.

Therefore, according to this embodiment, in addition to the effect of the above-described first embodiment, there is an effect that a multi-pole stator having four or more poles can be provided at a lower cost. Notable for stators. In the magnet holder 3 'of this embodiment, the protrusions 363 formed on both side surfaces of the connecting portion 36' are formed as ridges parallel to the direction in which the female mold M is pulled out.

At the inner peripheral ends of all the connecting portions 36 ', 36 ", there are formed ridges 364 having a triangular cross-section, which protrude on both sides in the circumferential direction. 364 engages with the chamfered corners of the inner peripheral surface of each permanent magnet at both ends in the circumferential direction, and securely holds the permanent magnets so that the circumferential opposite ends do not fall inside. have.

[Brief description of the drawings]

FIG. 1 is a half end view showing a configuration of a stator of a rotating electric machine as a first embodiment;

FIG. 2 is a cross-sectional view illustrating a configuration of a stator of the rotating electric machine as the first embodiment.

FIG. 3 is a side view showing the configuration of the magnet holder according to the first embodiment.

FIG. 4 is an enlarged view showing a configuration of a main part of the magnet holder according to the first embodiment.

FIG. 5 is an enlarged view showing an operation of a main part of the magnet holder according to the first embodiment.

FIG. 6 is a side view showing a configuration of a magnet holder according to a first modification of the first embodiment;

FIG. 7 is a cross-sectional view illustrating a shape and a manufacturing method of a magnet holder according to a second embodiment.

[Explanation of symbols]

1: Yoke 11: Bearing 2: Permanent magnet 21: End face in the circumferential direction 3, 3 ': Magnet holder (made of synthetic resin) 36, 36', 36 ": Connecting portion 31: Lightening hole 32: Frame portion 33, 35 : Solid portion 361, 362, 363: Projection 364: Protrusion 37, 37 ', 37 ": Ring portion 371: Projection 4: Holding cylinder 5: Stator 6: Front cap 61: Bearing Δh: Difference in projection height M: female type

Claims (4)

[Claims] 1. A substantially hollow cylindrical yoke made of a soft magnetic material, a plurality of permanent magnets fixed along the inner peripheral surface of the yoke at predetermined intervals in a circumferential direction, and these permanent magnets are used as shafts. It consists of two ring portions sandwiched from both ends in the longitudinal direction, and a plurality of connecting portions arranged to fill a predetermined circumferential interval between these permanent magnets and connecting these ring portions to each other. A magnet holder made of a synthetic resin that holds a permanent magnet in contact with the inner peripheral surface of the yoke, and a stator of the rotating electric machine, comprising: a stator formed on at least one of the coupling portion and the ring portion of the magnet holder A stator for a rotating electric machine, comprising: a lightening hole formed; and a plurality of projections at least partially facing the lightening hole and protruding opposite to the permanent magnets. At least half of the connecting portions of the magnet holder include at least one lightening hole formed in a radial direction, a solid portion having no lightening hole, and a solid portion having no lightening hole. The stator for a rotating electric machine according to claim 1, further comprising: the projection facing rearward, and the projection projecting higher than the projection and facing rearward of the lightening hole. 3. At least one of the ring portions of the magnet holder includes at least one lightening hole, a solid portion having no lightening hole, and the projection facing the solid portion. The stator for a rotating electrical machine according to claim 1, further comprising: a protrusion protruding higher than the protrusion, the protrusion being opposed to the lightening hole. 4. The connecting portion, wherein one set of two opposing connecting portions has a lightening hole, and the other pair of opposing connecting portions has no lightening hole. 3. The stator for a rotary electric machine according to any one of 3.