JPH0670517A - Manufacture of stator for slotless motor - Google Patents

Abstract

PURPOSE:To enhance the workability by inserting a coil portion to the inner periphery after inserting a stator core to a frame, by fitting an equivalent mold to a bracket portion and tightly adhering the coil portion to the inner surface and by injecting, heating and hardening a resin. CONSTITUTION:When producing a stator 4 for an inrevolvable slotless motor, insulating and protecting paper 8 is wound around an elastic hollow body 7 having a rubber-based air pressuring and exhausting portion 7a, and a first coil 6a is placed around the surrounding. Then, coils 6a after the second step are shifted to peripheral direction, and a cylindrical coil 6 is obtained after overlapping the sides of adjacent coils if required. Thereafter, the insulating and protecting paper 9 is wound around the cylindrical coil 6, one united body of the hollow body 7, the cylindrical coil 6, and insulating paper 8 and 9 is inserted to stator core 5 and to a frame 1 in this state, and air is injected to the hollow body 7 after installing a bracket also used as a mold. Under this conditions, a resin is injected in vacuum and the resin is hardened in a drying oven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stator of a slotless motor in which a coil for forming a rotating magnetic field is mounted on an annular stator core having no slots.

[0002]

2. Description of the Related Art Conventionally, as an adder type motor having a rotor inside a stator with an appropriate gap, a stator is obtained by mounting a coil inside an annular stator core without slots. There is a slotless motor. In the case of the stator of this inner rotor type slotless motor, a plurality of coils for forming the rotating magnetic field are assembled into a cylindrical shape that matches the inner peripheral shape of a simple annular laminated iron core without slots, and a cylindrical coil It is constituted by molding the periphery of the body with a resin, solidifying and shaping, fitting the inner periphery of the laminated iron core through an insulating layer, and fixing by adhesion in this state. As a specific example of the slotless motor stator configured in this way, the one described in JP-A-1-252134 is known.

That is, as shown in FIG. 8 and FIG. 9, the coil of each phase of U, V and W is roughly bisected and wound into two layers, an inner layer and an outer layer. Specifically, first, the U-phase coil u,
Half of u'is wound in the range of electrical angle 60 degrees, then this U
Half of the V-phase coils v, v ′ are also wound in the range of an electrical angle of 60 ° at a position advanced by 120 ° in the armature angle from the phase-coils u, u ′, and subsequently, more than the V-phase coils v, v ′. 1 in electrical angle
Half of the W-phase coils w and w'are wound at a position advanced by 20 degrees within an electrical angle range of 60 degrees.

Further, the other half of the U, V, and W phase coils u, u ', v, v', w, and w'are wound on the outer side of these coils. The windings A, V, V ′, W, W ′ are wound in the same manner within the range of electrical angles of 60 degrees from the end position of the winding, and finally, the coil body A is substantially cylindrical in the inner and outer layers. Is configured. Then, the coil body A is fixed and shaped into a cylindrical shape by the resin 22, and then fixed to the inner circumference of the annular core 21 via the insulating layer 23. Further, as a method of manufacturing a stator for this type of slotless motor, for example, Japanese Patent Application Laid-Open No. 3-1073
The one described in Japanese Patent No. 54 is known.

That is, the manufacturing method described in this publication is
After inserting a plurality of coils in a cylindrical shape into the inner circumference of an annular stator core having no slots, a round bar-shaped inner diameter jig is set inside the cylindrical coils by insertion. In such a set state, the cylindrical coil, the stator core, and the inner diameter jig are immersed in a thermosetting impregnating resin (or varnish) as they are in an integrated state, and then those integral parts are pulled up to obtain the impregnating resin. Each step of curing and then removing the inner diameter jig is executed.

[0006]

However, in the above-described conventional manufacturing method, the step of setting the inner diameter jig by inserting it inside the coil shaped into a cylindrical shape is performed. For this reason, when carrying a cylindrical coil in a shaped state or when inserting the cylindrical coil into the stator core, it is necessary to take care so that the inner diameter of the cylindrical coil does not become out of order. At the same time, a step of removing the inner diameter jig is required after the impregnating resin is hardened, and thus there is a problem that the manufacturing workability is generally poor.

The present invention has been made in view of the above circumstances. An object of the present invention is to manufacture a cylindrical coil without resin-molding, without damaging the cylindrical coil and without requiring a draft in an inner diameter jig. (EN) Provided is a method for manufacturing a stator for a slotless motor, which has a minimum gap size that can improve workability and improve torque characteristics.

[0008]

In order to achieve the above object, the present invention provides a stator of an annular slotless rotary electric machine, which has a cylindrical shape after a slotless annular stator core is inserted into a frame. A non-woven fabric made of an insulating material is arranged on the elastic hollow body, and a coil portion having a winding for forming a rotating magnetic field is inserted on the inner periphery of the stator core.
After fitting the equivalent type of the bracket part to the frame part and the elastic hollow body, press-fit air into the elastic hollow body to bring the coil part into close contact with the inner surface of the stator core, and also to the bracket part. So that the resin does not leak. After that, the resin is cast and heated and cured in a drying oven, and then the air inside the elastic hollow body is removed, and the elastic hollow body is removed to form a rotating electric machine in which the frame, the stator core and the coil portion are integrated. To get the stator of. In this case, the corresponding bracket type may be shared with the product bracket.

[0009]

In order to dispose the non-woven fabric on the elastic (rubber-like) hollow body, the non-woven fabric can be impregnated with resin to form a necessary insulating layer. The outer diameter of the elastic hollow body is smaller than a predetermined dimension when air is not pressed therein. For this reason, after forming a plurality of coils on this in a roughly cylindrical shape, it is inserted into the annular stator core, but since the outer diameter of the formed cylindrical coil is slightly smaller than the inner diameter of the stator core, it is easy. Can be done. After that, by fitting the corresponding type of the bracket portion and then pressurizing air into the elastic hollow body, the coil is pressed against the inner peripheral side of the stator core by the elastic hollow body. At this time, since the elastic hollow body has a cylindrical shape, the outer diameter is uniformly increased, and the coil can be closely attached to the inner peripheral side of the stator core while forming the coil.

Further, the resin can be prevented from leaking from this portion by closely contacting with the hole portion corresponding to the bearing portion of the bracket portion. The inner circumference of the coil is also made of this elastic hollow body,
It is more cylindrically shaped. This elastic hollow body serves as an inner mold, and after casting and heat curing, the outer diameter of the elastic hollow body can be reduced by releasing the internal air and can be easily removed. Therefore, manufacturing workability is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic cross-sectional structure of an inner rotor type slotless motor. In FIG. 1, the rotor 2 designated through a bearing (not shown) in the frame 1 is provided with a permanent magnet 3 for forming four magnetic poles. Also, frame 1
Three-phase four-pole stator 4 provided so as to surround the rotor 2 inside
Is a cylindrical coil composed of an annular slotless stator core 5 fixed to the inner periphery of the frame 1 and a plurality of coils 6a mounted on the inner periphery of the stator core 5 for forming a rotating magnetic field. 6 and 6. In this embodiment, the stator 4 has a three-phase, four-pole structure, and twelve coils 6a are provided accordingly.

FIG. 2 shows the cross-sectional shape of the coil 6a together with its arrangement example. However, four coils 6a of the first phase (U phase) are connected to U1 to U4 and four coils of the second phase (V phase), respectively.
The individual coils 6a are represented by V1 to V4, and the four coils of the third phase (W phase) are represented by W1 to W4, respectively.

In FIG. 2, coils U1 to U4, V1
To V4 and W1 to W4, each coil side pair has a mechanical angle of 9
It is arranged in a cylindrical shape along the inner circumference of the stator core 5 by sequentially arranging it in the circumferential direction so as to occupy each 0 degree, and is configured to satisfy the following three conditions. (1). Each coil has a shape in which the number of turns of the coil side in the radial direction of the stator core 5 decreases toward the inner circumference.

(2). In the state of being arranged in a cylindrical shape, the adjacent coil sides are in a state of overlapping in the radial direction at the turn number reduced portion of (1) (in this example, the entire coil side).

(3). The distribution of the number of turns on each coil side as in (1) is in a state of continuously changing in the range of 60 electrical degrees, and in this example, it is changed in a sine wave shape. Now, the stator 4 having the above-mentioned configuration is manufactured through the following steps.

That is, first, as shown in FIG. 3, the air is made of rubber, which is an elastic material that withstands the curing temperature of the resin.
An elastic hollow body 7 having a discharge portion 7a (hereinafter simply referred to as the hollow body 7
Prepared). The central portion of the hollow body 7 is substantially equal to the height dimension (axial dimension) of the cylindrical coil 6, and the outer dimensions determine the inner diameter dimension of the cylindrical coil 6 when air is pressed into the hollow coil 7. Is set to a predetermined size.

An insulating protective paper 8 such as a nonwoven fabric made of polyester, aramid and glass fiber is wound around the hollow body 7. After that, the first coil 6a is arranged around the insulating protection paper 8 and, after this,
The coil 6a after the first coil is displaced in the circumferential direction, and adjacent coil sides are arranged so as to be overlapped with each other as necessary, and finally the cylindrical coil 6 as shown in FIG. 4 is obtained. After that, as shown in FIG. 5, a non-woven insulating protective paper 9 made of polyester, aramid, glass fiber or the like is wound around the cylindrical coil 6. The insulating protective paper 9 may be arranged on the inner circumference of the stator core 5.

When the coils 6a are arranged as described above, an insulating paper (not shown) such as a polyester film or aramid paper is sandwiched between the coils 6a,
They function as insulating paper between coils.

Next, as shown in FIG. 6, the hollow core 7, the cylindrical coil 6 and the insulating protective papers 8 and 9 are integrated into the stator core 5.
It is inserted inside, and in this state, it is inserted into the frame 1 which also serves as the outer shape. After that, a bracket 10 that also serves as a mold is attached to the frame 1, and then air is pressed into the hollow body 7. In this state, as shown in FIG. 7, after injecting the resin 11 in a vacuum, the resin is cured in a drying furnace to obtain a stator in which the cylindrical coil 6, the stator core 5 and the frame 1 are integrated.

According to the structure of the present embodiment described above, in performing the resin molding process for the cylindrical coil 6, the hollow body 7 serves as an inner mold for resin molding, but by removing air from the inside, Since the outer diameter of the hollow body 7 becomes small, it can be easily removed even after the resin is cured. Also, when the coil 6 is inserted into the stator core 5, the outer shape of the coil can be kept small, so that the insertion into the stator core 5 can be facilitated.

Moreover, it is usually necessary to provide a draft for these inner molds, but since this gradient is unnecessary, the gap between the stator and the rotor after molding can be set to a minimum, and the torque characteristics are sacrificed. There is no need to Also, when the insulation thickness of the inner circumference is required for insulation and protection,
If a thick non-woven cloth made of glass mat is used for the protective paper wound around the inner circumference, this part can be impregnated with resin to obtain a strong insulating layer, and this thickness can be easily adjusted by voltage and capacity. You can also do it.

[0022]

According to the present invention, as is clear from the above description, when the resin molding of the cylindrical coil is performed, the cylindrical elastic hollow body used for forming the annular coil is made of resin. Since it is configured so as to play the role of a mold during molding, it is easy to release the resin mold. Further, since the fitting portion of the bracket portion also serves as a packing, there is no resin leakage during molding, workability is improved, and a predetermined insulating dimension can be easily secured.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an entire slotless motor of the present invention.

FIG. 2 is a coil layout diagram of the slotless motor of the present invention.

FIG. 3 is a perspective view showing a state where the stator according to the first embodiment of the present invention is being assembled.

FIG. 4 is a perspective view showing a state where the stator according to the second embodiment of the present invention is being assembled.

FIG. 5 is a perspective view showing a state where the stator according to the third embodiment of the present invention is being assembled.

FIG. 6 is a perspective view showing a state where the stator according to the third embodiment of the present invention is being assembled.

FIG. 7 is a schematic view of the stator of the present invention during casting.

FIG. 8 is a coil layout diagram of a conventional slotless motor.

FIG. 9 is a schematic sectional view of a stator of a conventional slotless motor.

[Explanation of symbols]

1 is a frame, 2 is a rotor, 4 is a stator, 5 is a stator core, 6 is an annular coil,
6a is a coil, 7 is an elastic hollow body, 8 and 9 are insulating protective paper, 11 is resin.

Claims (2)

[Claims] 1. In a stator of an annular slotless rotating electric machine, an annular stator core without slots is inserted into a frame, and a winding is formed after winding a nonwoven fabric on a cylindrical elastic hollow body. The arranged coil part is inserted into the inner circumference of the stator core, and the corresponding mold of the bracket part is fitted to the frame part and the elastic hollow body, and air is pressed into the elastic hollow body to press the inner surface of the stator and the bracket. Close to the corresponding type of part,
After that, the resin is cast, and after heating and curing, the internal air of the elastic hollow body is removed, and the elastic hollow body is removed to obtain a stator in which the frame, the stator core and the coil portion are integrated. And a method for manufacturing a stator for a slotless motor. 2. The method for manufacturing a stator for a slotless motor according to claim 1, wherein the elastic hollow body is made of rubber.