JPS6258861A - Synchronous motor - Google Patents

Abstract

PURPOSE:To suppress the rotational unevenness of a rotor and obtain the smooth rotation, by forming boundaries between the respective poles of the rotor on a motor with the disc-formed rotor and a disc-formed stator confronted with each other, with polygonal lines or curves. CONSTITUTION:A winding unit having eddy-formed winding elements is laminated via an insulating sheet, to form a disc-formed stator 20, and the stator 20 is confronted with a disc-formed rotor 18 with poles N and poles S arranged alternately on one side surface in the circumferential direction, to form a synchronous motor. In its case, boundaries 31 between respective poles arranged on the rotor 18 are formed with polygonal lines which are radially extended on the whole and bent on the way, or with curves. As a result, even if the winding unit conductor is widened, the rotational unevenness of the rotor can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synchronous motor, and more particularly to the boundary shape of magnetic poles of a rotor.

[Conventional technology]

Conventionally, a synchronous motor is known in which a stator and a rotor are formed into disk shapes, and these disk-shaped stators and rotors are arranged alternately in the axial direction so as to face each other. The stator is formed by laminating a winding unit consisting of spiral winding elements arranged in the circumferential direction and an insulating sheet, while the rotor is formed by laminating N and S poles in the circumferential direction. It is made of magnet.

The stator is made by etching a thin sheet of metal such as copper, by coating a conductive metal on a film base with a predetermined winding pattern, or by placing a conductive metal in a predetermined position using a press or other method. ,or,
It is formed by forming an insulated enameled wire into a spiral shape, placing it in a predetermined position, and solidifying it with a resin or the like. Since such a stator does not have an iron core, the electric motor has little cogging and rotational unevenness is relatively small.

(Problem to be solved by the invention) In order to obtain a large output torque in a synchronous motor, it is necessary to increase the conductor occupation rate in the stator. A relatively wide conductor is often used. However, in the case of such a wide conductor,
When the boundaries of the rotor's magnetic poles are close to the conductor, the magnetic flux density changes, and therefore the rotational force experienced by the portion of the rotor that is close to the conductor changes. Therefore, the wider the width of the conductor, the greater the number of conductors passing through the boundaries of the magnetic poles, resulting in uneven rotational force of the rotor.

In order to prevent such uneven rotation of the rotor, a configuration has been proposed in which the boundaries of the magnetic poles of the rotor are inclined in one direction (Japanese Patent Application No. 83607/1983). Although it is effective when the conductors are arranged radially with respect to the axis, in reality, the conductors are not arranged strictly radially through the axis, and it is difficult to completely eliminate rotational unevenness.

[Means for solving problems]

The synchronous motor according to the present invention is characterized in that the boundary between each N pole and S pole of the rotor has a polygonal line shape or a curved shape extending substantially radially from the axis of the rotor.

〔Example〕 The present invention will be explained below with reference to illustrated embodiments.

FIG. 2 shows a synchronous motor 10 to which the present invention is applied, 12
14 is its rotating shaft, and 14 is a stator housing. A rotor 18 made of a disk-shaped permanent magnet is attached to the rotating shaft 12 via a non-magnetic support 16. Rotor 18
is magnetized so that a magnetic field is formed along a direction parallel to the axis of the electric motor 10. A disk-shaped stator 20 is attached to the stator housing 14 . Stator 2
0 and the rotor I8 are arranged alternately in the axial direction of the electric motor lO, and the magnetic field from the rotor 18 described above is transferred to the stator 20.
A relative rotational force is generated between the rotor 18 and the stator 20 by cutting off the current flowing in the radial direction from the motor axis through the armature winding attached to the motor.

The stator 20 is formed by overlapping several stator elements 21, and the stator element 21 has an armature winding unit 7) 23 on both sides of an insulating sheet 22, as shown in FIG.
．． 24 are laminated.

That is, on one side surface of the insulating sheet 22, a plurality of (six in this case) winding units 23 each consisting of a pair of winding elements A, B, are arranged in the circumferential direction and fixed to the insulating sheet 22. On the other surface of the insulating sheet 22, a plurality (six in this case) of S-wire units 24 each consisting of a pair of winding elements Ax and Bz are arranged in the circumferential direction and fixed to the insulating sheet 22.

FIG. 4(a) and tb+ show spiral winding elements A, , B, respectively. Winding element A1 is formed in a spiral shape complementary to the spiral shape of winding element B+. Both the S-wire element A1 and the winding element B are obtained by press-forming a copper plate, and the winding element B almost corresponds to the scraps from pressing the winding element A1. However, S line element A
and winding element B are obtained by individually press-forming, and are fundamentally different from press waste.

That is, since the winding element A1 and the S-wire element B have complementary spiral shapes, each of these elements At and B+ mutually forms the spiral of the opposite winding element B l +AI, as shown in FIG. Therefore, the winding element A and the winding element B can be overlapped most densely on the same plane. Both elements A, , B are press-molded in advance to have dimensions such that there is a small clearance between them so that they do not come into contact with each other in this superimposed state.

One structural unit obtained by superimposing both elements A, B, is indicated by an arrow X in FIG. 3, and when forming the stator element 21, such a structural unit
As shown in the figure, they are arranged to form a circle on one plane. The winding unit 24 is arranged to be shifted from the winding unit 23 by one pitch (one spiral) in the circumferential direction. The insulating sheet 22 includes the winding elements A of the winding units 23 and 24.

Holes 25 are provided at positions corresponding to both ends of B+, Az, and Bz, respectively, and winding elements A+ and B+ of the winding unit 23 and winding elements Az of the winding unit 24,
Bz are connected within the hole 25 by means such as welding. As a result, the winding element A1 of the winding unit 23 and the winding element Az of the winding element 24 are sequentially coupled to form one coil loop A, as shown in FIG. Winding elements BI+BZ are sequentially connected in the same manner as on the right to form one coil loop B. Coil loops A and B are separated at bridges 26 and 27, respectively.

In each stator element 21, the winding unit 23
between the winding elements A, , Bt of the winding unit 24 and the winding element A2 . B, it is necessary to ensure a gap for insulation between each, and it is also necessary to ensure a gap between adjacent winding units 23 and between adjacent winding units 24, respectively. In order to increase the space factor of the coils in the stator element 21, these gaps are set as small as possible. Therefore, it is necessary to position the winding elements A+, B+, Az, and Bz of the winding units 23, 24 on the surface of the insulating sheet 22 with high precision.

FIG. 1 shows rotor 18. FIG. On the upper surface of the rotor 8, N poles and S poles are alternately magnetized at 45° intervals, and a boundary 31 between each N pole and S pole has a polygonal shape.

These boundaries 31 are composed of an inner circumferential portion 31a formed of a radial line passing through the axis of the rotor 18, and an outer circumferential portion 31b inclined in the circumferential direction with respect to the inner circumferential portion 31a. By forming the boundary 31 into a polygonal line shape in this way, when the radially extending portion C (see FIG. 3) of each conductor of the winding units 23 and 24 of the stator 2o passes near the boundary 31, the magnetic flux is reduced. There is no sudden change, and therefore there is very little unevenness in the rotational force of the rotor 18.

FIG. 6 shows temporal changes in rotational force (torque).

The broken line I shows the change in the rotational force when the boundary 31 is a radial straight line passing through the axis, and the actual gJ shows the change in the rotational force in the embodiment of FIG. As a result of making the boundary 31 into a polygonal line shape in this way, the unevenness of the rotational force that the rotor 18 receives is reduced, and the rotation of the rotor 18 becomes smoother.

FIG. 7 shows a rotor 18 in a second embodiment. The boundary 31 in this rotor 18 has an arc shape, and this also provides the same effect as the embodiment shown in FIG. 1.

FIG. 8 shows the rotor 18 in the third embodiment.

In this rotor 18, each boundary 31 exhibits a polygonal line bent at two places, and this also produces the same effect as each of the above embodiments.

Note that the rotor 18 may be magnetized according to a predetermined pattern, or may be formed by arranging magnets that are previously formed into a required shape.

〔Effect of the invention〕

As described above, according to the present invention, even if the width of the conductor of the winding unit is widened in order to obtain high output, the unevenness of the rotational force applied to the rotor can be suppressed to a considerably small level, and the rotation of the rotor is made smooth. You can get the effect that you can.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a rotor according to a first embodiment of the present invention, FIG. 2 is a sectional view showing a synchronous motor, FIG. 3 is an exploded perspective view showing a stator element, and FIGS. bl is a plan view showing each winding element, Fig. 5 is a diagram showing the connection state of the winding elements of the stator element, Fig. 6 is a graph showing temporal changes in the rotational force of the rotor, and Fig. 7 is a diagram showing the connection state of the winding elements of the stator element. FIG. 8 is a plan view showing a second embodiment of the rotor, and FIG. 8 is a plan view showing a third embodiment of the rotor. 10... Synchronous motor, 18... Rotor, 20... Stator, 22... - Insulation unit, 23, 24... Winding unit, 31... Boundary, ^+, B+, Ax, Bz... Winding element. 18... Rotor Figure 2 Figure 3 (a) ( b) Figure 4 Figure 5 Time Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. A disc-shaped stator formed by laminating a winding unit in which spiral winding elements are arranged in the circumferential direction and an insulating sheet; In a synchronous motor equipped with a disk-shaped rotor in which north poles and south poles are alternately magnetized in the circumferential direction on the side surface, the boundary between each north pole and south pole of the rotor is located from the axis of the rotor. A synchronous motor characterized by having a polygonal or curved shape extending substantially radially.