JP2004040991A - Brushless direct-current motor without requiring rotation magnetic field - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and clear, and inexpensive brushless direct-current motor without contacts to be worn down by rotation except a bearing part which is a bearing of a rotor in which a high-degree, complicated, and expensive control circuit for forming a rotation magnetic field is removed as unnecessary. <P>SOLUTION: The brushless direct-current motor driven only by Lorentz force of a drive coil mounted to a stator is developed by arranging and mounting permanent magnets on the rotor side so that the magnetic field direction is not changed at all in all the upper, lower, right and left directions. Also, it is made to have a multiple and multi-staged structure in order to increase output. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric machine that generates a mechanical driving force by connecting a DC power supply, that is, a DC motor that does not use a brush, that is, a brushless DC motor among DC motors.
[0002]
[Prior art]
The simplest DC motor structure in the past is to place N and S permanent magnets on the left and right sides of the rotating shaft as outer stators, and wind electric wires around the rotating cylindrical rotor in parallel with the rotating shaft. A direct current is supplied to the electric wire from a commutator attached to the rotating shaft.
Since the magnetic poles of the left and right stators are different, it is necessary to reverse the direction of the current on the left and right of the rotor as the rotor rotates, and the commutator is placed for switching, and these are the sliding parts. In addition, the use of brushes has the disadvantage that the life of the motor is shortened due to wear and noise is generated.
The idea was brushless DC motors. This is a conventional DC motor using a permanent magnet on the stator side as a rotor and removing the commutator, that is, the sliding portion and the brush.
[0003]
[Problems to be solved by the invention]
In conventional brushless DC motors, it is necessary to create a rotating magnetic field for pulling and rotating a permanent magnet of a rotor from a direct current by a coil placed on a stator side. The use of generation and control circuits has resulted in a new problem of increasing the manufacturing costs of DC motors.
In view of the above, an object of the present invention is to provide a brushless DC motor that does not require the use of a control circuit for generating a high-level rotating magnetic field using a semiconductor.
[0004]
[Means for Solving the Problems]
In the conventional brushless DC motor, the polarity of the permanent magnet used for the rotor is opposite to N or S on the left and right sides of the rotation axis of the rotor. Therefore, there was no way to rotate and drive the rotor from the outside, other than to create a rotating magnetic field.
Therefore, in the present invention, the magnetic field direction of the magnet used for the rotor is arranged in a parallel or radial array with respect to the rotation axis, and the drive coil mounted as a stator on the outside has the magnetic field direction of the magnet of the rotor. When the magnetic field direction is arranged in a radial array from the rotation axis, the current is arranged parallel to the rotation axis. They are arranged to flow.
In this way, unlike a conventional brushless DC motor, the direction of the magnetic field of the magnet used for the rotor does not become opposite to the left and right or up and down with respect to the rotation axis, but is attached as a stator outside. When viewed from the viewpoint of the drive coil, even when the rotor makes one rotation with the rotation of the rotor, the direction of the magnetic field of the rotor magnet that crosses a certain point of the drive coil is always in a fixed direction, so that a rotating magnetic field is unnecessary. It is considered that the rotor can be directly rotated and driven by the generated Lorentz force by flowing a direct current in a certain direction through the drive coil.
Considering the most suitable arrangement of magnetic poles for brushless DC motors and raising the conditions,
1. In order for the rotor and the stator to move relative to each other without collision, there must be "space" between the rotor and the stator.
2. Considering that a force is exchanged in the "space" and a conductor, that is, a drive coil, which is one side of the exchange of the force, is placed on either the rotor or the stator, the "space" is defined as a "magnetic field". It must be space.
3. In order to make a DC motor, the “magnetic field” of the “magnetic field space” is preferably a “static magnetic field oriented in one direction”.
4. The current flowing through the drive coil must always be flowed in the same direction, maintaining an angle of 90 degrees with respect to both the "static magnetic field in one direction" and the "rotation direction of the rotor". .
5. It is considered that the “unidirectionally oriented static magnetic field” and the size of the area of the electric wire of the drive coil will affect the output of the motor, so the “unidirectionally oriented static magnetic field space” should be as large as possible. Good.
The best solution that can be considered from these conditions is that the magnetic field direction of the magnet used for the rotor is arranged parallel or radial to the rotation axis, and the drive coil mounted as a stator on the outside When the magnetic field direction of the child magnet is parallel to the rotation axis, on the contrary, it is arranged so that current flows radially from the rotation axis, and when the magnetic field direction is arranged in a radial array from the rotation axis, It is arranged so that a current flows parallel to the rotation axis. "
The magnet used for this rotor may be made of an electromagnet instead of a permanent magnet, or, alternatively, the driving coil may be mounted on the rotor by reversing the positions of the rotor and the stator, and the stator may be replaced with a permanent magnet. However, considering that brushless is desirable and that the simpler the structure is, the lower the cost will be, `` Place a drive coil on the stator side and place a strong permanent Attach a magnetic pole made of a magnet "is probably the most desirable model.
Furthermore, when it is desired to increase the output, it is considered that it is best to use "a rotor having a multi-stage structure in which a large number of permanent magnets are mounted on the same shaft". In this case, between the disks in each stage, Since the drive coils on the stator side have a structure in which the drive coils are inserted one by one, all the magnetic poles of the permanent magnet toward the one-stage drive coil must be the same in order to unify the driving directions of the rotor. That is, the direction of the magnetic field of the magnet disk attached to the rotor must be made to be parallel to the rotation axis and to be reversed step by step. Accordingly, the drive coils must also be connected such that the rotation direction of the drive current is reversed for each stage.
(See the model of Example 5)
[0005]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1 FIG. FIGS. 1 and 2 show one embodiment of the present invention in which the direction of the magnetic field of the permanent magnet attached to the rotor is arranged parallel to the rotation axis. The portion to be produced, that is, the conductor of the coil on the surface where the drive coil and the permanent magnet face each other, is wound radially from the rotation axis.
[0006]
Embodiment 2. FIG. FIGS. 3 and 4 show one of the simple models of the present invention in which the direction of the magnetic field of the permanent magnet attached to the rotor is radially arranged with respect to the rotation axis.
Among them, the portion that generates the Lorentz force, that is, the coil conductor on the surface where the drive coil and the permanent magnet face each other, is wound in parallel with the rotation axis.
[0007]
Embodiment 3 FIG. FIG. 5 shows one of the embodiments of the present invention in which the direction of the magnetic field of the permanent magnet attached to the rotor is arranged parallel to the rotation axis and radially, and is considered to be a simple model. is there.
This is a combination of the models of the first embodiment and the second embodiment, which are combined. However, for the sake of simplicity, the outer permanent magnet attached to the rotor of the second embodiment, which is considered difficult to manufacture. Has been removed to create a composite model.
It is thought that power is great for simple.
[0008]
Embodiment 4. FIG. FIG. 6 shows Embodiment 3 of the present invention. The drive coil of the model was changed from a square to a cylinder (doughnut) type, and the arrangement of the permanent magnets was changed accordingly.
For the production, Example 3. May be more technically difficult than the previous model.
[0009]
Embodiment 5 FIG. FIG. 7 shows Embodiment 3 of the present invention. Is a multi-stage model. Of course, the number of stages can be freely changed according to the output.
It should be noted here that in order to unify the driving directions of the rotor, all the magnetic poles of the permanent magnets directed to the one-stage drive coil need to be the same. Therefore, the permanent magnets of the rotor must have their magnetic poles inverted for each stage of the disk, and accordingly, the drive coils must also be connected such that the direction of rotation of the drive current is inverted for each stage.
All the models of the first to fourth embodiments can be similarly formed in other stages to increase the output, and require the same attention as in the present case.
However, Example 5. It is thought that this model is the most practical model that is simplest, has a large output, and can be manufactured at low cost. In this case, manufacturing the radial drive coil on a printed board may be a good manufacturing method.
[0011]
【The invention's effect】
Except for the bearings, which are the bearings of the rotor, there are no contact parts that are worn by rotation, and a simple and clear DC motor can be realized. An inexpensive DC motor can be obtained.
At present, small DC motors are used in various fields, and it is considered that the present invention also has wide applications. (
[Claims 1 and 2])
[0012]
Normally, a DC motor that does not use a special control circuit generates an electromotive force at both ends of a drive coil to be supplied with power when a rotor that is a mechanical drive system is rotated, so that it can be used as a generator. It is well known that the DC motor of the present invention also operates as a DC generator. (
(3)
[0013]
When two DC motors of the present invention are prepared and both rotors are mechanically coupled, and one is used as a DC generator and used as a secondary DC power supply, this is a DC rotary current transformer,
That is, it is clear that the dynamic DC transformer is used. ([Claim 4])
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a model of a first embodiment as viewed from the side.
FIG. 2 is a conceptual diagram of a model according to a first embodiment. FIG. 3 is a cross-sectional view of the model according to the second embodiment as viewed from the side.
FIG. 4 is a conceptual diagram of a model according to a second embodiment.
FIG. 5 is a cross-sectional view of a model of Example 3 as viewed from the side.
FIG. 6 is a cross-sectional view of a model of Example 4 as viewed from the side.
FIG. 7 is a cross-sectional view of a model of Example 5 as viewed from the side.
[Explanation of symbols]
Numbers 1 to 5 in the figures are all common in FIGS. The rest are additional parts.
1 Drive coil and stator (integral).
2 Permanent magnet and rotor (integral).
3 Drive current and its direction.
4. The magnetic poles of the permanent magnet and the direction of the magnetic field.
5 Bearing part.
6 Rotor shaft 7 Drive coil (radial)
8 Rotor shaft 9 Drive coil (parallel to rotating shaft)

Claims (4)

The direction of the magnetic field of the permanent magnet attached to the rotor (* 1) is parallel or radial to the rotation axis, and the magnetic poles are the same in all directions, up, down, left, and right, when viewed from the direction of the rotation axis. The drive coil arranged and mounted as a stator (* 2) on the outside is arranged such that when the magnetic field direction of the magnet of the rotor is parallel to the rotation axis, the current flows in the radial direction from the rotation axis. When the direction of the magnetic field is radially arranged from the rotation axis, the stator is arranged so that current flows in parallel with the rotation axis and the driving force is directly obtained from the Lorentz force of the driving coil to rotate the stator. A brushless DC motor that does not require a magnetic field generation and control circuit.
* 1: It is also called a rotor or an armature, and a linear motor is also called a mover, but since it mainly uses a rotating system, the following text uses the rotor corresponding to the English rotor in a unified manner.
* 2: Stator, which is also called field magnet in Japanese, is used in the following sentence for the stator corresponding to the English stator. In order to improve the drive output, a rotor having a multi-layered structure in which a plurality of permanent magnets are attached to the same shaft to stack rotating disks, and a multi-stage structure corresponding to the stacked structure are provided. A brushless DC motor having a drive coil on a stator and configured so that all the magnetic poles of the permanent magnets are directed to the drive coil forming one stage so that the magnetic poles are all the same. A DC generator having a structure similar to the electric motor described in claim 1 or 2. A DC motor having a structure similar to the motor described in claim 1 or 2, or a DC rotary current transformer using a DC generator.

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