JPH03230745A - Stepping motor - Google Patents

Abstract

PURPOSE:To make thin a motor by arranging magnetic poles of the first electromagnet so as to hold a single polarization width between them, and arranging magnetic poles of the second electromagnet so as to hold the single split region between them at a position deviated by a half split width of a rotor. CONSTITUTION:A rotor 2 is divided into four sections, and it is alternately polarized into N and S poles and is polarized into N and S in the front and rear thereof. The first electromagnet 3 is such that the end 3a1 of a yoke 3a thereof is polarized into N and S poles and that it has approximately the same as a single polarization width of the rotor 2. The second electromagnet 4 is in a position deviated by a half of polarization width of the rotor 2 from a symmetrical position of the first electromagnet 3. Forms of the ends 3a1 and 4a1 and another ends of yokes 3a and 4a of the electromagnets 3 and 4 are the same as a form of polarization of the rotor 2, and both ends 3a1 and 4a1 is deviated from the symmetrical position by approximately a half polarization width of the rotor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a small stepping motor, particularly a P M with improved two stators of the same shape and asymmetrical arrangement.
Regarding the structure of type stepping motor.

"Prior Art" The applicant of the present application disclosed in Japanese Patent Application No. 1-140068 a rotor consisting of a disk-shaped permanent magnet in which N and S poles are alternately arranged in a plurality of radially divided regions; P is composed of a first electromagnet having a magnetic pole facing the divided rotor magnetic pole, and a second electromagnet having a magnetic pole opposite to the divided rotor magnetic pole with a half magnetic pole width deviation.
We proposed an M-type stepping motor.

``Problem to be Solved by the Invention'' However, this motor structure is not suitable when a thin motor is required because the electromagnets are disposed on the upper and lower surfaces of the disc-shaped rotor.

"Means and Effects for Solving the Problems" In order to realize a thin and efficient PM stepping motor, the present invention is supported by a motor shaft and alternately has N and S poles in a plurality of radially divided regions. The rotor consists of a disk-shaped permanent magnet that is magnetized to N and 8 on the front and back, and the magnetic poles are arranged so as to sandwich the width of a substantially single divided region of this rotor. magnetic poles are arranged so as to sandwich a substantially single divided width region at a position offset from a position symmetrical to the motor axis with respect to the first electromagnet by approximately one-half divided width of the rotor. The stator is composed of a second electromagnet and a second electromagnet.
This stepping motor has a large diameter and operates in a thin shape.

Embodiment FIGS. 1 to 3 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a motor shaft, and only the lower part is shown and the upper part is omitted. 2 is the rotor, which is radially divided into four parts.
It is alternately polarized to N and S poles, and N and 8 polarized on the front and back surfaces. Note that even if the number of divisions is 6 or more, it can be used. 3 is a first electromagnet, 3a is a yoke, the end portion 3a is polarized to N and S poles, and has a width substantially equal to the width of a single segment of the rotor 2; 3b is an excitation coil. A second electromagnet is located at a position shifted by approximately half the polarization width of the rotor 2 from a symmetrical position to the first electromagnet 3, but is not shown in this figure.

2(a) and 2(b) show an embodiment in which the stepping motor of the present invention is disposed on upper and lower donut-shaped substrates 5, 5', and the same members as in FIG. 1 are indicated by the same symbols.

The shapes of the ends 3a and 4a1 of the yokes 3a and 4a, and the other ends 3a and 4a2 (not shown) are approximately the same shape as the polarization of the rotor 2, and both ends 3a and 4a have approximately half the polarization of the rotor. It is deviated from the symmetrical position. 6 and 7 are gears that take out the output. FIG. 3 is a diagram for explaining the rotation of the rotor in various drive modes of the stepping motor having the configuration of the embodiment shown in FIG.
When currents M and M2 shown in a) are passed, the relationship between the electromagnet and each magnetic pole of the rotor as shown in FIG.

That is, as shown in the drawings from the left to the right in FIG. 3(b), initially the upper yoke terminal of the second electromagnet M is magnetized to the N pole, and the lower yoke terminal is magnetized to the S magnet. The upper pole attracts the south pole on the upper surface of the expanded rotor, and the lower 8 poles attract the north pole on the lower surface of the expanded single rotor, so the rotor is rotated in the direction of the arrow, that is, in the clockwise direction.

In the diagram on the right, the upper yoke terminal of the first electromagnet M1 is magnetized to the S pole, the lower yoke terminal is magnetized to the N pole, and the upper S pole is developed and attracted to the upper surface of the rotor, and the lower N
In order to pull S on the lower surface of the rotor with the expanded poles, rotate the rotor in the direction of the arrow, that is, clockwise, as shown in the left figure. Thereafter, clockwise driving force is generated one after another in the same manner as shown in the figure on the right, and the rotor continues to rotate.

Similarly, the first. Apply G to the second electromagnet as shown in (c) figure.
When currents such as Ml and M are applied (a), the rotor rotates as shown in the figure.Similarly, when a current mode as shown in the figure (e) is applied, the rotational force as shown in the figure (f) is generated. Occur.

"Effects of the Invention" By using the VC structure of the present invention, a thin and efficient stepping motor can be obtained.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, FIG. 1 is a schematic perspective view showing the basic configuration of the present invention, FIG. 2 is a schematic diagram of the arrangement on a donut-shaped substrate, and FIG. 3 is a rotation of the rotor. FIG. ...Motor shaft 0-ta 3...First electromagnet...Second electromagnet/board

Claims (1)

[Claims] N in a region that is supported by the motor shaft and divided into multiple radials.
, a rotor consisting of a disk-shaped permanent magnet that is alternately magnetized with S poles and N and S polarized on the front and back sides, and a first rotor whose magnetic poles are arranged so as to sandwich a substantially single divided region width of the rotor. an electromagnet, and a second electromagnet having magnetic poles arranged so as to sandwich a substantially single divided width region at a position offset by approximately one-half divided width of the rotor from a symmetrical position with respect to the motor axis with respect to the first electromagnet. A stepping motor comprising a stator comprising an electromagnet.