JP2000341894A - Internal structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize sufficient insulation between a core and a winding and reduce the size of a motor. SOLUTION: A motor MT has a rotary shaft 1, a core 2 which is fixed to the rotary shaft 1 and has teeth 10 protruding in the radial directions and extending in the axial direction, an insulating member 3 which has winding application parts 30 and is electrically insulating and windings 4 wound on the winding application parts 30. The length in the circumferential direction of each axial direction end part of the tooth 10 is shorter than the length in the circumferential direction of the middle part 38 between both the end parts in each axial direction of the tooth 10, and further, the outer surfaces of the corner parts 31, 32, etc., between the respective flat plane parts of the winding application parts 30 are formed into circular arc shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal structure of a motor, and more particularly to an internal structure of a motor in which windings are wound around teeth of a core fixed to a rotating shaft via an insulating member. .

[0002]

2. Description of the Related Art Conventionally, as an internal structure of this kind of motor, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 10-225040 is known.

[0003] The internal structure of the motor disclosed in this publication is as follows.
As shown in (a) and (b) of FIG. 9, a core having teeth portions protruding radially outward and extending in the axial direction, and both end surfaces in the axial direction and circumferential end surfaces of the teeth portions mounted on the core are defined as follows. A resin insulating member having a winding winding portion to be covered, a projection formed in a portion of the winding winding portion excluding a corner portion, a guide groove provided with the projection, and a winding inserted in the guide groove. A winding wound on the winding portion, and a step is formed between a bottom surface of the guide groove and a surface of the winding portion.

[0004]

However, in the motor structure disclosed in the above publication, the insulating member that electrically insulates the core is made of resin (for example, PBT), and the surface of the teeth portion is In this configuration, if the thickness of the insulating member is small and the strength of the insulating member is low, the winding may be caught or bitten by the insulating member made of resin. Also, if the shape of the corner part of the winding part is almost a right angle,
The winding is sharply bent at the corner, and the tension (the tightening force of the winding) is concentrated locally. Therefore, when the winding is wound around the winding portion of the insulating member, the insulating coating of the winding is easily damaged, and the insulation durability is reduced. Furthermore, if the winding is provided on the rotating side, the coating of the winding will be peeled off by the rotating force, and if the winding is short-circuited to the core, it will not function sufficiently as a motor. .

In other words, even if the outer surface of the corner portion of the winding portion is formed in an arc shape, if the radius of curvature is small and close to a right angle, the winding and the corner portion do not come into surface contact with each other. It becomes close to contact and cannot sufficiently absorb the tension applied to the winding, and the tension causes cracks at the corners of the winding portion. For example, looking at the region A in the winding part of the teeth shown in FIG. 9B, the winding is bent at the positions B and C, so that the tension is dispersed, but as described above. If the radius of curvature at the B position and the C position is small, the tension is locally concentrated at the B position and the C position.

In order to increase the radius of curvature at the B position and the C position, the thickness of the corner portion is reduced, or the thickness of the winding portion having no projection is reduced. Need to be thicker. However, when the former method is adopted, the thickness of the corner portion is reduced, so that cracks are more likely to occur in the corner portion. In addition, when the latter method is employed, the height of the winding is increased, which hinders winding of the winding.

Further, in the configuration disclosed in the above-mentioned publication, in addition to the thickness required for insulation, the thickness of the projection is required to further provide a guide groove, and the winding when winding is wound. The height of the line becomes higher by the height of the convex portion, and as a result, the motor becomes larger.

Therefore, the present invention has been made in view of the above-mentioned problems, and the thickness of the insulating member is made larger than the thickness required for insulation so that the winding height can be increased without increasing the winding height. It is a technical task to achieve sufficient insulation from a winding.

[0009]

Technical means taken to solve the above-mentioned problems include a rotating shaft, a core fixed to the rotating shaft and having a tooth portion protruding radially outward and extending in the axial direction. An insulating member having a winding winding portion attached to the core and covering both axial end surfaces and circumferential end surfaces of the teeth portion,
In the internal structure of the motor having a winding wound on the winding part so as to be electrically insulated from the core by the insulating member, the circumferential length of both ends in the axial direction of the teeth part is increased. The outer surface of the corner portion between each flat portion of the winding portion along the axial end surfaces and the circumferential end surface of the teeth portion, while making the length smaller than the circumferential length of the intermediate portion between the axial end portions. Is formed in an arc shape.

According to this, the circumferential length of both ends in the axial direction of the teeth portion is made smaller than the circumferential length of the intermediate portion between the both end portions in the axial direction. By simply forming the outer surface of the corner between the flat portions of the winding portion along the circumferential end surface in an arc shape, the radius of curvature of the outer surface of the arc portion is determined by the thickness required for insulating the thickness of the flat portion. It is possible to increase the size while maintaining the thickness. Thereby, the strength at the corner portion is increased, sufficient insulation can be performed even when the winding is wound, and the winding height does not increase.

In this case, if the thickness of the corner portion of the winding portion of the insulating member is made larger than the thickness of each flat portion, the thickness of the corner portion can be reduced without increasing the thickness of the flat portion. Thicker,
The thickness of the corners can be made thicker than the thickness of the flat part without increasing the thickness of the flat part of the insulating member compared to the past, so the strength of the insulating member at the corner part is further improved. However, even if the winding bites or bites into the insulating member, sufficient insulation can be achieved.

A guide groove is provided in one of the flat portions and a part of the corner portion connected thereto, and the winding is wound around the guide groove, so that the guide grooves are formed in the flat portion and the corner portion. The winding is wound by being guided by the tension, so that the tension is not locally concentrated unlike the related art. In this case, it is not necessary to partially form the convex portion for providing the guide groove, so that the size of the motor can be reduced.

Further, if the length of the teeth in the circumferential direction is continuously reduced from the intermediate portion to both ends in the axial direction, sufficient insulation can be achieved only by changing the shape of the teeth.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of the motor MT according to the first embodiment of the present invention. The rotor RT has a core 2 fixed to the rotating shaft 1 by press-fitting or fitting. The core 2 includes a plurality of disk-shaped metal members 10 each of which has a plurality of radially (here, 10 poles) teeth portions 10 having a substantially T-shape in the circumferential direction with respect to the center of rotation of the core. Plate plates are laminated in the direction of the rotation axis. The winding 4 is applied to the teeth 10 of the core 2,
In order to electrically insulate the winding 4 from the abdomen of the teeth portion 10 (the circumferential end surface 36 and the axial end surface 37 which are narrowed in the circumferential direction in the T-shaped tooth portion 10), both sides of the core 2 in the axial direction are provided. Insulating members (insulators) 3a, 3b conforming to the core shape shown in FIG.
7 and the circumferential side wall (circumferential end face) 36 of the abdomen
a, 3b and are electrically insulated. When the insulating members 3a and 3b are mounted, the outer peripheral surface of the core is exposed without being covered by the insulating members 3a and 3b. With the insulation from the core 2 maintained, the winding 4 is wound around the winding part 30, which is the part of the insulating members 3a and 3b that cover the periphery of the narrowed abdomen of the teeth part 10.

FIG. 1 shows a state in which two teeth portions 10 are skipped and the winding 4 is wound only at one place for simplicity for the sake of explanation. The windings 4 are wound around all the teeth 10 via the insulating members 3a and 3b while being shifted one by one in the circumferential direction.

Each end 4a, 4b of the winding 4 wound around the teeth 10 is connected to a hook 1 press-fitted and fixed to the rotating shaft 1.
1 and are fixed by welding or the like. Each hook 11 is electrically connected to the commutators 6 provided in a number corresponding to the number of the teeth portions 10 made of a material having high conductive efficiency such as Cu.

The rotating shaft 1 is supported by the housing on both sides of the core 2 by bearings. Under the state in which the rotating shaft is supported by the bearings, the rotating shaft 1 faces the outer diameter of the disc-shaped laminated core 2. The magnet 5 having the curved surface facing the opposite side is fixed to a housing (not shown) at a predetermined distance. With such a configuration,
By applying a voltage from the outside via a brush electrically connected to the commutator 6, a current flows through the winding 4 inside the motor, whereby a magnetic flux is formed between the core 2 and the magnet 5, Rotor R by electric suction / repulsion
T is rotatably supported by both ends and becomes rotatable.

In the above, the outline of the internal configuration of the motor MT has been described. Next, the present invention will be described. In the present invention, the corner portions 31 to 3 of the T-shaped teeth portion 10 are formed.
4 is characterized. The core 2 is made up of several plate members (for example, the material is SPC270D) formed by press working as shown in FIG. 2, and the plate members are laminated in the direction of the rotation axis and fixed to the rotation shaft 1. And insulating members 3a, 3
b covers the axial end face 37 and the circumferential end face 36. The insulating members 3 a and 3 b have a structure that completely covers the abdomen (the circumferential end surface 36 and the axial end surfaces 37) of the T-shaped teeth 10 of the laminated core 2. Radius of curvature (curvature) of
Plane portion 3 formed between corner portions 31 to 34 having
At the corners 31 to 34, both ends in the axial direction of the teeth 10 are set so that the thickness of the teeth 5 (the part of the teeth 10 where the core 2 is laminated and which is a plane) is not more than the thickness necessary for insulation. The circumferential length of the surface 37 is made smaller than the circumferential length of the intermediate portion 38 formed between both end surfaces in the axial direction of the insulating member 3 covering the core 2 from the axial direction, and the outer surface at the corner portions 31 to 34 ( Outer periphery) is formed in an arc shape. As a result, the corner portions 31 to 34
The insulating member 3 has a shape (R shape) having a curvature dr equal to or greater than the thickness d in the plane portion 35 existing in the intermediate portion 38,
The thickness at the corner portions 31 to 34 is larger than the thickness at the flat portion 35 (dr> d). Thus, the corner portions 31 to 31 can be formed without changing the thickness of the insulating member 2 beyond the thickness required for insulation only by changing the core shape at both ends in the axial direction.
The radius of curvature at 34 becomes large, so that the winding 4 is sharply bent at the corners as in the prior art, and it is possible to prevent the tension from being concentrated locally and to prevent the coating of the winding 4 from being damaged. can do.

That is, conventionally, all the cores laminated in the rotation axis direction have the same shape, and if the thickness of the plane portion 35 other than the corner portion is to be made the same in the rotation axis direction and the circumferential direction, The wall thickness at the corner portions 31 to 34 becomes thin. When the winding 4 is wound there, when the insulating member 3 is formed of resin, the insulating member 3 cuts into or bites into the resin, and cracks occur. On the other hand, in order to increase the strength at the corner portions 31 to 34, a method of winding the winding 4 around the winding portion 30 of the insulating member 3 by increasing the thickness of the insulating member 3 as a whole is also considered. However, this increases the size of the motor itself. In order to solve this, a configuration is adopted in which the thickness d of the conventional flat portion 35 is maintained, and the resin strength is improved at the corner portions 31 to 34. Specifically, the thickness (= curvature) dr of the corner portions 31 to 34 in the winding portion 30 of the insulating member 3 (3a, 3b) is compared with the thickness d of the flat portion 35 formed therebetween. , 2b, 2b of the core 2 (2u,..., 2b) on which the plate member is laminated.
When the circumferential size of the middle portion 38 in the abdomen of the teeth portion 1 is L, the circumferential size of the teeth portion 1 in the circumferential direction is L-2d (r-1) smaller than L.
By providing plate members at both ends 2 u and 2 d of the lamination at a position retracted by d (r−1) from the intermediate portion 38, the thickness of each of the corner portions 31 to 34 is set to dr, and the thickness of the flat portion 35 is set to d. be able to.

Therefore, when the winding 4 is wound around the winding part 30, the thickness of the flat part 35 of the insulating member 3 is not increased to d or more than in the conventional case, and the corner parts 31 to 34 are formed.
The thickness can be increased, and the strength can be improved.

Next, a second embodiment will be described. FIG. 5 is basically the same as the first embodiment shown in FIGS. 1 to 4, except that the shape of the insulating members 3 a and 3 b shown in FIG. Is different in that a guide groove 3ag is provided in the entire area of the lamination end face in the direction of the rotation axis including the corner portions 31 to 34 of FIG. The guide groove 3ag can be provided in either the axial end face 37 or the flat face 35 in the circumferential end face 36 and a part of the corners 31 to 34 connected thereto. In FIG. Are provided between the circumferential corners. By providing such a guide groove 3ag, when winding the windings 4 in layers on the insulating member, as shown in FIG. In addition, it is possible to accurately align and wind the wire, and the winding volume can be reduced. In this case, the corners 31 to 34
The guide groove 3ag is provided continuously from
Is wound, the winding 4 is guided from the beginning by the guide groove 3ag.
Corners 31
Similarly to the above, the radius of curvature in the range from to 34 is larger than that of the related art, so that the tension is not locally concentrated, the wound can be prevented from being damaged, and the reliability is improved. .

The above-described guide groove 3ag can be provided in the whole area of the winding part 30 around which the winding of the teeth part 10 is wound, and may be provided in the direction of the rotation axis. It may be provided in the axial direction and the circumferential direction.

Further, in another embodiment, the same effect can be obtained by continuously reducing the circumferential length of the core 2 in the teeth portion 10 from the intermediate portion 38 to the axial end portions 37. Can be. That is, this corresponds to the shape of the corner portions 31 to 34 at both ends of the lamination in the axial direction of the core 2 in the direction of the rotation axis, and the end 2ut in the circumferential direction corresponds to the third end in FIG.
As shown in the embodiment, the corner portions 31 to 34 may be tapered so as to be thick, and the circumferential end 2 ur of the axial end of the tooth portion 10 is always uniform. As shown in the fourth embodiment in FIG. 8, the shape may be an R shape.

For example, in the present embodiment, 16 cores 2 each having a thickness of 1 mm are laminated, the thickness of the insulating member 3 at the flat portion 35 is 0.4 mm, and the corner portions 31 to 34 are formed. Is 1.4 mm.

[0025]

According to the present invention, the circumferential lengths of both ends of the teeth in the axial direction are made smaller than the circumferential lengths of the intermediate portions between the both ends in the axial direction, and both end surfaces of the teeth in the axial direction are reduced. In addition, simply forming the outer surface of the corner portion between the flat portions of the winding portion along the circumferential end surface in an arc shape, the curvature radius of the arc-shaped corner portion outer surface is required to insulate the thickness of the flat portion. It is possible to increase the thickness while maintaining the wall thickness.
Thereby, the strength at the corner portion is increased, sufficient insulation can be performed even when the winding is wound, and the winding height does not increase.

In this case, if the thickness of the corner portion of the winding portion of the insulating member is made thicker than the thickness of each flat portion, the thickness of the corner portion can be reduced without increasing the thickness of the flat portion. Thicker,
The thickness of the corners can be made thicker than the thickness of the flat part without increasing the thickness of the flat part of the insulating member compared to the past, so the strength of the insulating member at the corner part is further improved. However, even if the winding bites or bites into the insulating member, sufficient insulation can be achieved.

Further, a guide groove is provided in one of the flat portions and a part of the corner portion connected thereto, and the winding is wound around the guide groove. The winding is wound by being guided by the tension, so that the tension is not locally concentrated unlike the related art. In this case, it is not necessary to partially form the protrusion for providing the guide groove, so that the motor can be downsized.

Further, if the circumferential length of the tooth portion is continuously reduced from the intermediate portion toward both ends in the axial direction, sufficient insulation can be achieved only by changing the shape of the tooth portion.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an internal structure of a motor according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a tooth part shown in FIG.

FIG. 3 is a sectional view taken along line AA shown in FIG. 2;

FIG. 4 is an enlarged view of a main part of a corner shown in FIG. 3;

FIG. 5 shows a second example in which a guide groove is provided in the insulating member shown in FIG.
It is an important section partial enlarged view showing the structure of the teeth part in an embodiment.

FIG. 6 is a schematic view showing a state where a winding is wound around a guide groove shown in FIG. 5;

FIG. 7 is a plan view of a third embodiment in which a core shape at a corner shown in FIG. 4 is changed.

FIG. 8 is a plan view of a fourth embodiment in which a core shape at a corner shown in FIG. 4 is changed.

9A and 9B are views showing a structure of a tooth portion of a conventional motor, wherein FIG. 9A is a perspective view of a tooth portion, and FIG.
FIG. 3 is a cross-sectional view of the abdomen in the teeth portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation axis 2 Core 2u, 2b Both ends of a core 3, 3a, 3b Insulating member (insulator) 3ag Guide groove 4 Winding 5 Magnet 10 Teeth part 30 Winding winding part 31, 32, 33, 34 Corner part 35 Flat part 36 Circumferential end face (circumferential end) 37 Axial end face (axial end) 38 Intermediate part MT motor

Claims (4)

[Claims] 1. A core having a rotating shaft, a core fixed to the rotating shaft, and protruding radially outward and extending in the axial direction, and both end faces in the axial direction and circumferential end faces of the teeth mounted on the core. And a winding wound on the winding part so as to be electrically insulated from the core by the insulating member. In the internal structure, the circumferential length at both axial ends of the teeth portion is smaller than the circumferential length at an intermediate portion between the axial ends, and the axial end surfaces of the teeth portion and An internal structure of a motor, wherein an outer surface of a corner portion between respective flat portions of the winding portion along a circumferential end surface is formed in an arc shape. 2. The internal structure of a motor according to claim 1, wherein a thickness of the corner portion of the winding portion of the insulating member is larger than a thickness of each of the flat portions. 3. A guide groove is provided in one of the flat portions and a part of the corner portion connected thereto,
The internal structure of a motor according to claim 2, wherein the winding is wound around the guide groove. 4. The internal structure of a motor according to claim 1, wherein the length of the teeth in the circumferential direction is continuously reduced from the intermediate portion toward both ends in the axial direction.