JPS61139241A - Synchronous motor - Google Patents

Abstract

PURPOSE:To precisely control by smoothly operating a synchronous motor at a low speed by partly altering the width of an armature winding formed in a spiral pattern to make said width approach a current distribution to a sinusoidal wave. CONSTITUTION:An armature winding 20 having a spiral pattern is radially formed on the surface of a stator disk 18. Permanent magnets are radially mounted in response to the winding 20 of the disk 18 on a rotor disk. The winding 20 is so formed as to be dense at the portions 20a-20c of outside and rough at the portions 20d-20f of inside. Thus, a current distribution becomes sinusoidal wave, a smooth motorrotation is obtained, and large torque can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a synchronous motor, and more particularly to the structure of an armature winding of a disk-type AC servo motor using permanent magnets.

BACKGROUND OF THE INVENTION With improvements in permanent magnet materials, the advantages of AC servo motors are gaining attention. As one type of AC servo motor using permanent magnets, there is a disk-type motor 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.

Permanent magnets are attached to the a-coils, while armature windings are attached to the stator with spiral f-turns. As an example of this type of motor, Applied Mechanical Engineering 198
A small flat servo motor is explained in the May 3rd issue. According to this explanation, a group of orange ring-shaped coils are formed as armature windings on the stator surface by photo-etching.

As the armature winding, copper wire or a press-molded copper plate can generally be used.

Problems to be Solved by the Invention The above-mentioned type of synchronous motor has the advantage of being small and capable of generating large torque.
Suitable as an AC servo motor. When using an AC servo motor in a direct drive system without using a reduction gear, it is required to be small and capable of generating large torque, and to operate smoothly at low speeds for precise control. Ru. When designing a stator winding structure, conventionally, emphasis has been placed on increasing output torque and reducing loss, and as a result, the current distribution is not sinusoidal. As a result, the motor does not rotate as smoothly as possible.

Means for Solving the Problems In order to solve the above problems, a synchronous motor according to the present invention has a plurality of disc-shaped stator elements having armature windings and a disc-shaped rotor element having permanent magnets that are aligned along the axis. In the case where the armature island wires are arranged alternately in the direction of the stator element, and the armature island wires are attached in continuous spiral grooves or turns along the surface of the stator element,
It is characterized in that the width of the armature winding attached by the winding turns is partially changed in order to make the current distribution closer to a sine wave.

Example Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 10 indicates a synchronous motor according to the present invention, 12 is its rotating shaft, and 14 is a stator 7'+Using. Three rotor disks 16 are attached to the rotating shaft 12, and four stator disks 18 are attached to the stator element 14. The surface of each stator disk 18 (C is spiral as shown in FIG. 2) and armature windings 20 having turns are provided radially.

Each winding 20 is a continuous piece, with the outer end connected to the power supply and the inner end connected to the back winding. Permanent magnets are radially attached to each rotor disk 16 in correspondence with the electric machine pre-winding lfM20 of the stator disk 18.

The stator disks 18 with the armature windings 20 and the rotor disks 16 with permanent magnets are arranged alternately in the axial direction of the motor, and the permanent magnets of the rotor disks 16 form a magnetic field along the motor axial direction, and the stator disks 18 have permanent magnets. 1
The radial direction portions 20a to 20f (FIG. 3.4) of the current flowing through the armature windings 20 of 8 cut off the magnetic field, thereby generating rotational force in the rotor disk 16. This rotational force can be increased as the current value increases, and
The number of windings 20 can be increased as the windings 20 become more densely arranged in a plane along the surface of the stator disk 18.

Each volume I! In order to make 1I20 as dense as possible, the fourth
As shown in the figure, it is preferable that the radially parallel portions 20a to 20F of each winding 2o are arranged closely to each other with an electrical insulating layer (not shown) interposed therebetween or at equal pitches with a slight gap between them. However, if this happens, the current distribution will deviate from the sine waveform, and the resulting torque will not have a sine wave shape either, impairing smooth rotation. In this specification, the current distribution is defined as t×ρ, where t is
The length of e, p is the portion 20a per unit distance in the circular direction
The number is 20f. In the present invention, in order to make the current distribution sinusoidal, as shown in FIG.
f are arranged roughly. Therefore, by correcting the current distribution, smooth rotation of the motor can be obtained, and at the same time, large torque can be generated. Each part 20a to 20f
In order to allow current to flow through the windings 20 without resistance, it is necessary to have a constant cross-sectional area from the outer end to the inner end of each winding 2069, and in order to change the pitch between each part 20a to 20f in a close state, It is necessary to vary the cross-sectional shape of the winding. That is, the dense portions 20&-20e have a small width and a small height, and the coarse portions 20d-20f have a large width and a small height.

The spiral armature winding 20 can be obtained by plastic deformation of a copper wire, press molding of a copper plate, etching, rede machining, electrical discharge machining, or the like. It should be noted that the reason why the outer parts 20a to 20e are made denser and the inner parts 20d to 20F are made coarser is simply to make the explanation easier to understand.Such changes are basically designed for individual volumes. Linear shape (e.g. Figure 4)
This is done appropriately to modify the current distribution, and the position and degree of change should be determined for each specific basic shape.

As described in detail, the present invention provides a synchronous motor that has excellent output characteristics and can be precisely controlled.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a synchronous motor according to the invention, FIG. 2 is a plan view of the stator disk of FIG. 1, FIG. 3 is a detailed view of the armature winding and the torque obtained thereby, and FIG. FIG. 4 is a diagram of a comparative example for explaining the armature winding of FIG. 3; 16... Rotor disk, 18... Stator disk, 20... Armature winding, 20a to 20f... Part of armature winding. 22 3rd country 4th country

Claims (1)

[Claims] 1. A plurality of disc-shaped stator elements having armature windings and disc-shaped rotor elements having permanent magnets are arranged alternately in the axial direction, and the armature windings are arranged along the surface of the stator element. In the case where the armature winding is attached in a continuous spiral pattern, the width of the armature winding attached in the spiral pattern is partially changed to make the current distribution closer to a sine wave. Features a synchronous motor.