JPH088767B2 - Single-phase motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-phase motor, and more particularly to a single-phase brushless motor that is compact and generates a large torque as compared with a conventional single-phase motor.

[Conventional technology]

Since the single-phase brushless motor has advantages such as high reliability and low cost, it is widely used for fan motors, spindle motors for information equipment, and the like.

FIG. 4 shows an example of a conventional single-phase brushless motor, and FIG. 4 (a) shows a rotor and a stator armature in an expanded manner.

In FIG. 4 (a), 10 is a rotor, which has north pole 11 and south pole 1
2. It consists of a non-magnetized portion 13. As the non-magnetized portion 13, an N-pole portion and an S-pole portion are provided at the same electrical angle to cancel the magnetic force to make it apparently non-magnetized.

Reference numeral 20 denotes a stator armature, which has a first magnetic pole generating portion 21 extending over an electrical angle of 120 ° and a second magnetic pole generating portion 22 extending over an electrical angle of 180 ° which is provided at a position different from the electrical angle of 180 °. ing.

In such a configuration, when either the first magnetic pole generating portion 21 or the second magnetic pole generating portion 22 is energized, in either case, as shown in FIG. Positive direction torque and negative direction torque are generated over 120 ° electrical angle (the first magnetic pole generating portion is shown in the figure.
21 shows the torque). Therefore, a continuous torque can be obtained by alternately energizing the windings of the magnetic pole generating portions 21, 22 by 180 °.

[Problems to be solved by the invention]

The above single-phase motor is widely used as a fan motor or a motor for a headphone cassette tape recorder. However, that the rotor 10 has the non-magnetized portion 13,
Since only one of the windings 21 and 22 of the stator armature 20 is energized alternately, only about 1/4 of the torque can be generated as compared with a three-phase reciprocating motor of the same size, which contributes to downsizing. Was a big problem.

The present invention has been made to solve the above-mentioned problems. By adding a third magnetic pole generating portion, reciprocal energization, that is, a magnetic pole is always generated at the first and second magnetic pole generating portions at the same time. An object is to provide a single-phase motor that can be energized.

[Means for solving problems]

A single-phase motor according to the present invention includes a first magnetic pole generating portion, a second magnetic pole generating portion provided at a position different in electrical angle by 180 ° from the first magnetic pole generating portion, and a first magnetic pole generating portion. A stator armature having a third magnetic pole generating portion for generating a magnetic pole having a constant polarity, which is provided between the second magnetic pole generating portion; and a first magnetizing portion, and the first magnetizing portion. A rotor having a second magnetized portion adjacent to and different in polarity from the second magnetized portion, and a non-magnetized portion.

[Action]

In the present invention, when the first and second magnetic pole generators are energized to generate magnetic poles of different polarities at the same time, the torque generated by these is combined with the torque generated by the third magnetic pole generator. , The combined torque is over 180 ° electrical angle. Therefore, the rotation without a dead center can be obtained by switching the energization direction to the first and second magnetic pole generators every rotation of the rotor by 180 ° electrical angle.

〔Example〕

FIG. 1 shows an embodiment of the present invention. FIG. 1 (a) shows a rotor and a stator armature in a developed state.
FIG. 1B shows a torque curve generated by the first and second magnetic pole generators, and FIG. 1C shows a torque curve generated by the third magnetic pole generator.

In FIG. 1 (a), 10 is a rotor, which has north pole 11 and south pole 1
2, which is composed of the non-magnetized portion 13 and is substantially the same as the rotor 10 shown in FIG.

Reference numeral 20 denotes a stator armature, which includes a first magnetic pole generating portion 21 extending over an electrical angle of 120 °, and a second magnetic pole generating portion 22 extending over an electrical angle of 180 ° at a position different from the electrical angle by 180 °.
The third magnetic pole generators 23 and 24 are provided between the first and second magnetic pole generators 21 and 22, respectively. Each magnetic pole generator 2
1, 22, 23, and 24 each have windings, and a magnetic pole is generated by causing a current of a predetermined magnitude and direction to flow through these windings from an energization control unit (not shown) at a necessary timing.

 Next, the operation will be described.

Now, when an N pole is generated in the first magnetic pole generating portion 21 and an S pole is generated in the second magnetic pole generating portion 22 by energization, as can be seen from the respective combined torques, positive and negative over 120 ° electrical angle. It has a torque generation section and two zero torque sections with an electrical angle of 60 ° between them. The positive / negative of this torque characteristic is reversed by reversing the energizing direction.

On the other hand, when the third magnetic pole generators 23, 24 are energized to generate the N pole, the result is as shown in FIG. 1 (c), and the combined torque of the two is obtained by the first and second magnetic pole generators. Positive torque is obtained only in the lack of torque region caused by 21,22, and negative torque is obtained in other parts. As a final combined torque (not shown) of the combined torque of FIG. 1 (c) and the combined torque of FIG. 1 (b), a positive torque over 180 electrical degrees is obtained. Therefore, a single-phase motor having no dead center can be constructed by appropriately switching the direction of energizing the windings of the first and second magnetic pole generators 21 and 22.

In this case, since the magnetic poles of the third magnetic pole generators 23 and 24 always have a constant polarity, the magnetic pole may be generated by providing a permanent magnet instead of the winding.

When the generated torque is controlled by adjusting the currents of the windings of the first and second magnetic pole generators 21 and 22, the torque of the third magnetic pole generators 23 and 24 is also controlled in proportion to it. It is preferable. In such a case, the third magnetic pole generator 23,2
To prevent torque ripple by making 4 generate magnetic poles by winding, and adjusting the winding current proportionally to the magnitude of energization to the first and second magnetic pole generating parts 21, 22. You can

2 (a) to (c) are explanatory views showing an example in which the present invention is applied to a cored motor.

FIG. 2 (a) shows an example in which the third magnetic pole generators 23 and 24 are constituted by windings, and is characterized in that the torque ripple is small and reverse rotation is possible during control.

FIGS. 2 (b) and 2 (c) show the case where the third magnetic pole generators 23, 24 are made of permanent magnets, and the ohmic cross is small and the third magnetic pole generators 23, 24 can be manufactured at low cost.

FIG. 3 shows an example in which the present invention is applied to a coreless flat motor. In this example, the first and second magnetic pole generators 21 and 22 are composed only of windings, and the magnetic pole generators 23 and 24 are composed of permanent magnets. As described above, the present invention is suitable particularly when thinning is required.

In the above embodiment, the first and second magnetic pole generators 21, 2
2 is provided over 120 ° electrical angle, and the N pole 11 and the S pole 12 which are the first and second magnetized parts are provided over 120 ° electrical angle. However, it is not always necessary to have such an electrical angle relationship.

〔The invention's effect〕

As described in detail above, according to the present invention, the third magnetic pole generating portion for generating the magnetic pole having a constant polarity is provided between each of the first magnetic pole generating portion and the second magnetic pole generating portion. It is possible to energize the windings of the first and second magnetic pole generators in a reciprocating manner, and there is an advantage that a small size, large torque, and inexpensive brushless single-phase motor can be obtained.

[Brief description of drawings]

1 (a) to 1 (c) show an embodiment of the present invention, and FIG. 1 (a) is a development view of a rotor and a stator armature,
1 (b) and (c) are torque curve diagrams, and FIG. 2 (a)-
(C) is an explanatory diagram when the present invention is applied to a cored motor, FIG. 3 is a diagram showing an example in which the present invention is also applied to a coreless motor, and FIGS. 4 (a) and 4 (b) are conventional single-phase motors. FIG. 4 (a) is an expanded view of the rotor and the stator armature, and FIG. 4 (b) is a torque curve diagram. In the figure, 10 is a rotor, 11 is an N pole, 12 is an S pole, 13 is a non-magnetized portion, 20 is a stator armature, 21 is a first magnetic pole generation portion, 22 is a second magnetic pole generation portion, 23, Reference numeral 24 is a third magnetic pole generator.

Claims (4)

[Claims] 1. A first magnetic pole generating portion, a second magnetic pole generating portion provided at a position different in electrical angle by 180 ° from the first magnetic pole generating portion, the first magnetic pole generating portion and the second magnetic pole generating portion. A stator armature having a third magnetic pole generating portion which is provided between the magnetic pole generating portions and generates a magnetic pole having a constant polarity; a first magnetizing portion;
A rotor having a second magnetized portion adjacent to the first magnetized portion and having a polarity different from that of the first magnetized portion; and a non-magnetized portion; and the first and second magnetic pole generating portions have opposite magnetic poles. The single-phase motor is characterized in that the respective windings are energized in a reciprocating manner, and the direction of energization is reversed every 180 ° electrical angle rotation of the rotor for driving. 2. A first magnetic pole generating section extending over an electrical angle of 120 °, and a second magnetic pole generating section extending over an electrical angle of 120 ° which is provided at a position different in electrical angle by 180 ° from the first magnetic pole generating section. A stator armature having a third magnetic pole generating portion which is provided between the first magnetic pole generating portion and the second magnetic pole generating portion and generates a magnetic pole having a constant polarity;
A rotor having a magnetized portion, a second magnetized portion adjacent to the first magnetized portion and extending over an electrical angle of 120 °, and a non-magnetized portion extending over an electrical angle of 120 °. And the second magnetic pole generating section reciprocally energize the windings respectively provided so as to generate the opposite magnetic poles, and the energizing direction is reversed every 180 ° electrical angle rotation of the rotor for driving. A single-phase motor according to claim (1) 3. A stator armature according to claim 1, wherein the third magnetic pole generating portion comprises a permanent magnet.
The single-phase motor according to the item. 4. The third magnetic pole generating portion of the stator armature is constituted by a winding, and is energized in a fixed direction regardless of the rotation of the rotor, and the magnitude of the current is the first and second magnetic pole generating portions. The single-phase motor according to claim (1), characterized in that the single-phase motor is proportional to the amount of electricity supplied to the motor.