JP2003153513A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor capable of attaining size reduction and high torque, and making the motor compact in the diameter direction thereof. SOLUTION: First to fourth rotating permanent magnets 21 to 24 which are polarized in the diametrical direction and in a circular-arc plate shape are attached to the circumferential surface of a rotor core 20 adjacent to each other. Poles of the first to fourth adjacent rotating permanent magnets 21 to 24 are different from each other. Six protruding iron cores 27 which protrude on a rotor 18 side are attached onto the inner periphery of a cylindrical part 13a of a yoke 13 at regular intervals. First to sixth coils L1 to L6 are wound around the respective protruding iron cores 27. The protruding iron cores 27 are integratedly formed with connecting iron cores 28 which cover the first to sixth coils L1 to L6 in a roughly U-shape. First to sixth stationary permanent magnets 31 to 36 which are disposed so that polarities may become different in the circumferential direction are sandwiched between the adjacent connecting iron cores 28. The first to sixth stationary permanent magnets 31 to 36 are disposed so that the same polarity of the adjacent permanent magnets may face each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor.

[0002]

2. Description of the Related Art Currently, motors are being developed in various fields such as the development of micro motors, the precision improvement of stepping motors, the reduction of power consumption, and the enhancement of torque. In particular, small motors with low power consumption and high torque are widely used in the fields of automobiles, office automation equipment, vending machines, medical and welfare equipment.

Normally, the motors used for these are
Most of the motors use permanent magnets, and they are technically quite mature, so it is difficult to achieve dramatic increase in efficiency and reduction in size and torque.

In order to reduce the size and increase the torque, for example, a motor using a hybrid magnet is known. For example, Japanese Patent Laid-Open No. 2000-150228 discloses a stepping motor including a hybrid magnet including both a coil and a permanent magnet. As shown in FIG. 10, in the hybrid magnet 61 of this publication, the U-shaped iron core 6 is used.
2, a coil 63 is wound around a body portion 62a provided on the stator so as to extend in the axial direction of the motor. Magnetic members 64 are respectively joined to the ends of both arm portions 62b extending from both ends of the body portion 62a in the radial direction of the motor, and a permanent magnet 65 is sandwiched between the magnetic members 64. The permanent magnets 65 are arranged so as to line up with the coil 63 in the radial direction of the motor.

[0005]

However, in the hybrid magnet 61 of this publication, since the coil 63 and the permanent magnet 65 are arranged side by side in the radial direction of the motor, the motor can be miniaturized in the radial direction. There is a problem that it is difficult.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a brushless motor that is small in size and high in torque and compact in the radial direction.

[0007]

In order to achieve the above object, the invention according to claim 1 is such that permanent magnets magnetized so that the polarities change in the radial direction have different magnetic poles adjacent to each other. A plurality of rotors arranged in the circumferential direction, a cylindrical portion of which one of the outer peripheral surface and the inner peripheral surface faces the rotor, and a plurality of fixed cores provided in the circumferential direction on the surface of the cylindrical portion facing the rotor. A hybrid magnet composed of a coil wound around the fixed iron core and sequentially fed with electric power so that the rotor rotates, and a fixed permanent magnet arranged between the fixed iron core so as to change polarity in the circumferential direction. A stator provided with a stator, wherein the fixed iron core has a base end connected to the cylindrical portion and a distal end formed to project toward the rotor, and a protrusion wound with the coil. iron And a connecting iron core that is formed in a substantially U-shape and covers the coil and has an end portion facing the cylindrical portion, the end portion of the connecting iron core being magnetically insulated from the cylindrical portion, and the fixed permanent magnet. Is abutted on the adjacent connecting cores at both ends thereof, and the fixed permanent magnets adjacent to each other are arranged so that the same magnetic poles face each other.

According to the present invention, the magnetic field lines of the fixed permanent magnet of the hybrid magnet constitute a closed circuit passing through the connecting iron core, the protruding iron core, and the cylindrical portion when the coil is not supplied with power, so that the magnetic force is exerted on the rotor side. Does not work.

When the coil is supplied with power, the magnetic force of the electromagnet bends the magnetic line of force of the fixed permanent magnet and directs it toward the rotor. Therefore, when the coil is fed with electric power, a strong magnetic force, which is the sum of the magnetic force of the electromagnet and the magnetic force of the fixed permanent magnet, acts on the rotor side from the hybrid magnet. By this strong magnetic force, the coils are sequentially supplied with electric power, whereby the permanent magnets of the rotor receive a tensile force and a repulsive force, and the rotor is rotated.

It is desirable to increase the magnetic flux density of the stator of the brushless motor as much as possible, but if it is increased, the stator becomes large. Moreover, when the amount of current is increased, heat generation is increased, resulting in energy loss. Therefore, by providing a hybrid magnet including a fixed permanent magnet, it is possible to obtain a stator of a brushless motor that has high torque and generates little heat.

Further, since the fixed permanent magnet and the coil are arranged in the circumferential direction, the size is reduced in the radial direction.
Therefore, the size and the torque can be increased, and the size can be reduced in the radial direction.

When the inner peripheral surface of the cylindrical portion faces the rotor, the brushless motor is an inner rotor type. On the contrary, when the outer peripheral surface of the cylindrical portion faces the rotor, the brushless motor is the outer rotor type.

According to a second aspect of the present invention, in the first aspect of the present invention, the number of magnetic poles of the permanent magnets of the rotor is four in the circumferential direction, and the number of the projecting iron cores is six. . According to the present invention, the two adjacent coils are fed with electric power, the predetermined permanent magnet of the rotor is rotated by the repulsive force and the pulling force, and when the pulling force comes closest to the center of the adjacent permanent magnet of the rotor. , Located between two coils capable of exerting a tensile force and a repulsive force on the permanent magnet. Therefore, the rotor is effectively rotated by supplying power to these two coils next, and the simplest and well arranged configuration can be obtained.

According to a third aspect of the present invention, a rotor having a plurality of radial projections, a cylindrical portion of the rotor facing one of the outer peripheral surface and the inner peripheral surface, and a surface of the cylindrical portion facing the rotor. A plurality of fixed iron cores provided in the circumferential direction, coils wound around the fixed iron core, and sequentially fed with electric power so that the rotor rotates, and arranged so that the polarity changes in the circumferential direction between the fixed iron cores. A fixed permanent magnet and a stator having a hybrid magnet including a fixed permanent magnet, wherein the fixed iron core has a base end connected to the cylindrical portion and a tip protruding toward the rotor. A projecting iron core formed by winding the coil, and covering the coil formed in a substantially U-shape, an end portion consisting of a connecting iron core facing the cylindrical portion, the end portion of the connecting iron core, Previous The invention is magnetically insulated from a cylindrical portion, the fixed permanent magnets are in contact with the adjacent connecting iron cores at both ends thereof, and the adjacent fixed permanent magnets are arranged so that the same magnetic poles face each other. To do.

According to the present invention, when the coil is not supplied with electric power, the magnetic lines of force of the fixed permanent magnet constitute a closed circuit passing through the connecting iron core, the protruding iron core and the cylindrical portion, as in the first aspect of the invention. Therefore, the magnetic force does not act on the rotor side.
Further, when the coil is fed with electric power, the magnetic force of the electromagnet bends the magnetic line of force of the fixed permanent magnet and directs it toward the rotor. Therefore, when the coil is fed with electric power, a strong magnetic force, which is the sum of the magnetic force of the electromagnet and the magnetic force of the fixed permanent magnet, acts on the rotor side from the hybrid magnet. Due to this strong magnetic force, the projections of the rotor receive a tensile force, so that the coils are sequentially supplied with electric power to rotate the rotor.

As described above, since the stator is provided with the hybrid magnet, the torque is strong and the heat generation can be reduced. Therefore, even if the rotor is not provided with the permanent magnet, the size and the torque can be increased. Further, since the rotor is not provided with a permanent magnet, the rotor can be manufactured at a lower cost.

Further, since the fixed permanent magnet and the coil are arranged in the circumferential direction, the size is reduced in the radial direction.
Therefore, the size and the torque can be increased, and the size can be reduced in the radial direction. The brushless motor is an inner rotor type when the inner peripheral surface of the cylindrical portion faces the rotor, and the outer rotor type when the outer peripheral surface of the cylindrical portion faces the rotor.

According to a fourth aspect of the present invention, in the third aspect of the invention, the circumferential width of the protrusion of the rotor and the circumferential width of the connecting core are substantially the same. And

According to the present invention, when the protrusion of the rotor is pulled by the magnetic force of the hybrid magnet and the protrusion of the rotor faces the connecting iron core that covers the coil in the electromagnet state, the iron core of the rotor and the connecting iron core are Face each other almost in the circumferential direction. Therefore, the rotor protrusion and
Leakage of magnetic flux is reduced between the core and the connecting core, and high torque can be effectively achieved.

According to a fifth aspect of the present invention, in the invention according to the third or fourth aspect, the circumferential width of the protrusion of the rotor is larger than the distance between the end faces of the adjacent connecting cores in the circumferential direction. Is the gist.

According to the present invention, when a protrusion of the rotor is pulled by the magnetic force of the hybrid magnet to rotate the rotor, and this protrusion faces the connecting core that covers the coil in the electromagnet state, another protrusion of the rotor is generated. The protrusion faces another connecting iron core in a part in the circumferential direction. Therefore, next, when power is supplied to the coil covered with the other connection iron core, between the other protrusion and the other connection iron core,
The magnetic flux passes through a part of the opposing circumferential direction, the protrusion is pulled, and the rotor continues to rotate. Therefore, the tensile force can be continuously applied to the rotor, and the rotor can be smoothly rotated.

According to a sixth aspect of the invention, in the invention according to any one of the third to fifth aspects, the rotor has four protrusions in the circumferential direction and six protrusion cores. ,
The gist of the coil wound around the projecting iron core is a three-phase coil in which the projecting iron cores facing each other by 180 ° are simultaneously fed.

According to the present invention, when the coil of a certain phase is fed with power and the two protrusions of the rotor are pulled and face the two coil sides constituting this phase, the remaining two protrusions of the rotor are Located between different coils. Therefore, the rotor of another phase can be effectively rotated by supplying power to the coil of another phase next, and the simplest and well-arranged structure can be obtained.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The first embodiment in which the present invention is embodied in an inner rotor type brushless motor will be described below.
1 to 5 will be described.

FIG. 1A shows a schematic sectional view of the brushless motor, and FIG. 1B shows a partial sectional schematic side view taken along line IB-IB of FIG. 1A. FIG. 5 is a graph showing the relationship between the rotation angle of the rotor and the energization state of the coil.

As shown in FIG. 1B, the brushless motor 11 includes a motor housing 12, and the motor housing 12 includes a bottomed cylindrical yoke 13 and an end frame 14. A bearing is fixedly provided at the center of each of the bottom portion of the yoke 13 and the end frame 14. A rotor 18 is housed in the space formed by the yoke 13 and the end frame 14. The rotary shaft 19 of the rotor 18 is rotatably supported by the both bearings.

As shown in FIG. 1 (a), the rotor core 20 of the rotor 18 is made of iron and is formed in a cylindrical shape. A plurality of permanent magnets are integrally rotatably attached to the peripheral surface of the rotor core 20. There is. In this embodiment, four arc plate-shaped permanent magnets are attached to the rotor core 20. These permanent magnets are replaced by the first rotary permanent magnets 21,
These are called the rotary permanent magnet 22, the third rotary permanent magnet 23, and the fourth rotary permanent magnet 24. Each of the first to fourth rotating permanent magnets 21 to
24 are formed to have the same length in the circumferential direction and are formed adjacent to each other. Therefore, in each of the first to fourth rotating permanent magnets 21 to 24, the angle formed by the center of the rotor 18 and both end surfaces is 90 °. When the rotor 18 is viewed from the end frame 14 side as shown in FIG.
The rotating permanent magnets 21 to 24 are sequentially arranged in the clockwise direction.

The first to fourth rotating permanent magnets 21 to 24 are magnetized so that the polarities change in the radial direction. In the drawing, only the magnetic poles on the radial direction side are shown and the magnetic poles on the radial direction inner side are shown. Omitted.

The first rotating permanent magnet 21 has N on the radially outer side.
It is arranged so that it may become a pole. In this embodiment, the N pole of the first rotary permanent magnet 21 is referred to as the N1 pole, the S pole of the second rotary permanent magnet 22 is the S1 pole, and the N pole of the third rotary permanent magnet 23 is the N pole.
The pole is called N2 pole, and the S pole of the fourth rotating permanent magnet 24 is called S2 pole.

The first to fourth rotating permanent magnets 21 to 24 are formed to have the same axial length as the rotor core 20. As shown in FIGS. 1A and 1B, the cylindrical portion 1 of the yoke 13
A protruding iron core 27 is attached to the inner peripheral surface of 3a. A plurality of projecting iron cores 27 are arranged in the circumferential direction of the yoke 13. In this embodiment, the six protruding iron cores 27 are
The yokes 13 are attached at equal angular intervals (60 ° intervals) in the circumferential direction. Each projecting iron core 27 has a cylindrical portion 13 at the base end.
It is attached to the inner peripheral surface of a and is formed so that its tip projects toward the rotor 18.

A winding is wound around each of the protruding iron cores 27 to form a coil. In this embodiment, the upper left coil in FIG. 1A is referred to as a first coil L1, and the other coils are sequentially arranged in a clockwise direction in FIG. 1A as a second coil L2, a third coil L3, and a fourth coil L3. Coil L
They are referred to as a fourth coil 5, a fifth coil L5, and a sixth coil L6.

First coil L1, third coil L3. The fifth coil L5 is wound around the projecting iron core 27 so that the radially inner side becomes the N pole and the radially outer side becomes the S pole when power is supplied. Conversely, the second coil L2, the fourth coil L4. The sixth coil L6 is wound around the projecting iron core 27 so that the radially inner side becomes the S pole and the radially outer side becomes the N pole when power is supplied.

Each protruding iron core 27 is formed integrally with the connecting iron core 28. Each connecting core 28 is substantially U-shaped and is formed so as to cover each of the first to sixth coils L1 to L6. The end of the connecting core 28 faces the cylindrical portion 13a. The protruding core 27 has a connecting core 28 at its tip.
It is continuous in the central part of. In addition, the cylindrical portion 1 of the yoke 13
An arcuate plate-shaped insulator 29 is attached to each of the first to sixth coils L1 to L6 at 3a, and the end of the connecting iron core 28 is attached to the cylindrical portion 13 by the insulator 29.
It is magnetically insulated from a. Protruding iron core 27, connecting iron core 28
The fixed iron core is constituted by.

A permanent magnet is sandwiched between adjacent connecting cores 28. In this embodiment, the first coil L1
The permanent magnet sandwiched by the second coil L2 and the second coil L2 is referred to as a first fixed permanent magnet 31, and the other permanent magnets are the second fixed permanent magnet 32 and the third fixed permanent magnet in the clockwise order in FIG. The magnet 33, the fourth fixed permanent magnet 34, the fifth fixed permanent magnet 35, and the sixth fixed permanent magnet 36 are called. The first to sixth fixed permanent magnets 31 to 36 are magnetically insulated from the cylindrical portion 13a by the insulator 29. Further, each of the first to sixth fixed permanent magnets 31 to 36 is formed such that the circumferential width thereof is smaller than the circumferential width of the connecting iron core 28.

The first to sixth fixed permanent magnets 31 to 36 are
It is formed so that the polarity changes in the circumferential direction. The first fixed permanent magnet 31 is formed so that the first coil L1 side has an N pole and the second coil L2 side has an S pole. The second fixed permanent magnet 32 is formed such that the second coil L2 side has an S pole and the third coil L3 side has an N pole. The third fixed permanent magnet 33 is formed so that the third coil L3 side has an N pole and the fourth coil L4 side has an S pole. Thus, the first to sixth fixed permanent magnets 31
Nos. 36 to 36 are arranged so that the same magnetic poles of adjacent permanent magnets face each other.

The cylindrical portion 13a of the yoke 13 and the protruding core 2
7, connection iron core 28, first to sixth coils L1 to L6, first
~ The sixth fixed permanent magnets 31 to 36 form a hybrid magnet. Further, the hybrid magnet and the motor housing 12 constitute a stator.

As shown in FIG. 1B, a hall element 41 is attached to the end frame 14 via a bracket so as to face the rotor 18. The brushless motor 11 detects changes in the magnetic flux of the first to fourth rotating permanent magnets 21 to 24 due to the rotation of the rotor 18 by means of the Hall element 41, and performs a predetermined calculation to thereby make the rotor 1
8 positions can be detected.

In this embodiment, as shown in FIG. 1A, the rotation angle θ of the rotor 18 is such that the central portion of the second rotating permanent magnet 22 having the S1 pole faces the first fixed permanent magnet 31. Therefore, the rotation angle θ is set to 0 °. The first to sixth coils L1 to L6 are the hall element 41.
Based on the rotational position of the rotor 18 detected by
Power is supplied as shown in the graph of FIG.

Next, the operation of the brushless motor configured as described above will be described. As shown in FIG. 2, when the first to sixth coils L1 to L6 are not supplied with power, the first coil
The magnetic lines of force of the fixed permanent magnet 31 are the portion of the connecting iron core 28 adjacent to the N pole on the side of the first fixed permanent magnet 31, the protruding iron core 27 around which the first coil L1 is wound, the cylindrical portion 13a, the second portion.
The projecting iron core 27 around which the coil L2 is wound and the connecting iron core 28 adjacent to the S pole constitute a closed circuit that passes through the portion on the first fixed permanent magnet 31 side. Therefore, the first fixed permanent magnet 3
The magnetic force of 1 does not act on the rotor 18 side.

Similarly, the magnetic lines of force of the second fixed permanent magnet 32 are the portion of the connecting iron core 28 adjacent to the N pole on the side of the second fixed permanent magnet 32, the protruding iron core 27 around which the second coil L2 is wound, and the cylindrical portion. 13a, a protruding iron core 27 around which the third coil L3 is wound, and a second connecting core 28 adjacent to the S pole.
A closed circuit that passes through the portion on the fixed permanent magnet 32 side is formed. Therefore, the magnetic force of the second fixed permanent magnet 32 also does not act on the rotor 18 side. Further, the magnetic force lines of the first fixed permanent magnets 31 and the magnetic force lines of the second fixed permanent magnets 32 pass through the protruding iron core 27 around which the second coil L2 is wound so as to be directed radially inward.

Similarly, the magnetic lines of force of the third fixed permanent magnet 33 are directed radially outward in the projecting iron core 27 around which the third coil L3 is wound, pass through the cylindrical portion 13a, and pass through the fourth coil L.
4 forms a closed circuit extending radially inward inside the projecting iron core 27 around which 4 is wound, and the magnetic force of the third fixed permanent magnet 33 is the rotor 1
It does not work on the 8 side. Therefore, the line of magnetic force of the second fixed permanent magnet 32 and the line of magnetic force of the third fixed permanent magnet 33 pass through the protruding iron core 27 in the third coil L3 so as to extend radially outward.

As described above, the first to sixth coils L1 to L6
In the state where the power is not supplied, the magnetic lines of force of each of the first to sixth fixed permanent magnets 31 to 36 are the connecting iron core 28 and the projecting iron core 2.
7. Since it forms a closed circuit that passes through the cylindrical portion 13a of the yoke 13, it does not act on the rotor 18 side.

The first coil L1, the third coil L3,
The magnetic force lines of the fixed permanent magnets pass through the projecting iron cores 27 around which the fifth coils L5 are wound so as to extend radially outward. Moreover, the magnetic force lines of the fixed permanent magnets pass through the projecting iron core 27 around which the insides of the second coil L2, the fourth coil L4, and the sixth coil L6 are wound so as to be directed radially inward.

As shown in FIG. 3, when the rotation angle of the rotor 18 is 0 °, the first coil L1 and the second coil L2 are supplied with power based on the fact that this rotation angle is detected by the Hall element 41. It

When the first coil L1 is fed with electric power and becomes an electromagnet, a magnetic field is generated in which the radially inner side of the first coil L1 has an N pole and the radially outer side thereof has an S pole. The magnetic field generated by the electromagnet causes the magnetic force lines to pass through the projecting iron core 27, around which the first coil L1 is wound, inward in the radial direction, which is opposite to the case of FIG. Therefore, the magnetic lines of force of the first and sixth fixed permanent magnets 31 and 36 cannot form a closed circuit passing through the projecting iron core 27 around which the first coil L1 is wound, and the magnetic lines of force from the N poles of both magnets are The magnetic field lines of the electromagnet formed by the one coil L1 move toward the rotor 18 side.

Therefore, in the connecting iron core 28 that covers the first coil L1, the magnetic force of the electromagnet by the first coil L1 and the first
A strong magnetic force, which is the sum of the magnetic forces generated by the sixth fixed permanent magnets 31 and 36, acts on the rotor 18 side.

When the second coil L2 is fed with electric power and becomes an electromagnet, the radially inner side of the second coil L2 becomes an S pole,
A magnetic field is generated such that the outer side in the radial direction becomes the N pole. Due to the magnetic field generated by the electromagnet, the magnetic field lines pass through the protruding iron core 27, around which the second coil L2 is wound, in the radially outward direction, which is the opposite direction to that of FIG. Therefore, the first and second
The magnetic lines of force of the fixed permanent magnets 31, 32 cannot form a closed circuit passing through the projecting iron core 27 around which the second coil L2 is wound, and the magnetic lines of force entering the S poles of both magnets together with the magnetic lines of force of the electromagnet by the second coil L2. , Enters each S pole from the rotor 18 side.

Therefore, also in the connecting iron core 28 covering the second coil L2, similarly, the magnetic force of the electromagnet by the second coil L2 and the magnetic force by the first and second fixed permanent magnets 31, 32 are combined to form a strong magnetic force. Acts on the rotor 18 side.

Therefore, the second rotating permanent magnet 2 of the rotor 18
In the S1 pole of No. 2, a repulsive force is generated between the S1 pole and the second coil L2 side, and a tensile force is generated between the S1 pole and the first coil L1 side.
Further, the N1 pole of the first rotating permanent magnet 21 receives a repulsive force between itself and the first coil L1 side, and the third rotating permanent magnet 23
The N2 pole at is subjected to a tensile force between itself and the second coil L2 side. In this way, the rotor 18 rotates counterclockwise in FIG. 3 due to the strong magnetic force, which is the sum of the magnetic force of the electromagnet and the magnetic force of the fixed permanent magnet, acting on the rotating permanent magnet.

As shown in FIG. 4A, the rotation angle of the rotor 18 becomes 30 °, and the central portion of the S1 pole is the first coil L.
When facing 1, the first coil L1 is not supplied with power,
The second coil L2 is continuously supplied with power, and the third coil L3 is newly supplied with power. Therefore, the magnetic lines of force of the second and third fixed permanent magnets 32 and 33 cannot form a closed circuit passing through the projecting iron core 27 around which the third coil L3 is wound, and the magnetic lines of force from the N poles of both magnets are The magnetic field lines of the electromagnet by the three coils L3 move toward the rotor 18 side.

Therefore, at the N2 pole of the rotor 18, a repulsive force is generated between the rotor 18 and the third coil L3 side, and a tensile force is generated between the rotor 18 and the second coil L2 side. The S1 pole is the second coil L2.
The S2 pole receives a repulsive force between itself and the side, and the S2 pole receives a tensile force between itself and the third coil L3 side. Therefore, the rotor 18 continues to rotate without stopping.

Similarly, as shown in FIG. 4 (b), the rotation angle of the rotor 18 becomes 60 °, and the central portion of the N2 pole is located at the second position.
When facing the coil L2, the second coil L2 is not supplied with power, the third coil L3 is continuously supplied with power, and the fourth coil L4 is newly supplied with power. Therefore, the magnetic force obtained by adding the magnetic forces of the third and fourth fixed permanent magnets 33 and 34 and the magnetic force of the fourth coil L4 acts on the rotor 18 side, and the rotor 18 continues to rotate.

Similarly, as shown in the graph of FIG. 5, two coils are fed at the same time, and one coil is the rotor 1
Power is continuously supplied while the 8 rotates by 60 °, and the first to sixth coils L1 to L6 are sequentially supplied each time the rotor 18 rotates by 30 °. As above
The rotor 18 is continuously rotated by a strong magnetic force obtained by adding the magnetic forces of the electromagnets by the first to sixth coils L1 to L6 and the magnetic forces of the first to sixth fixed permanent magnets 31 to 36.

Further, the rotor 51 rotates counterclockwise by supplying power to the coils in the order of the first coil L1, the second coil L2, the third coil L3, .... According to this embodiment, there are the following effects.

(1) In the brushless motor 11, a hybrid magnet is attached to the stator, and first to fourth rotating permanent magnets 21 to 24 are attached to the rotor 18.
Therefore, as the first to sixth coils L1 to L6 are sequentially fed with electric power, the rotor 18 has a strong magnetic force obtained by adding the magnetic forces of the first to sixth fixed permanent magnets 31 to 36 and the electromagnets. The rotor 18 can be rotated by exerting a tensile force and a repulsive force between the first to fourth rotating permanent magnets 21 to 24. Therefore, a small size and high torque can be achieved.

(2) First to sixth fixed permanent magnets 31 to 36
Since the first to sixth coils L1 to L6 are alternately arranged in the circumferential direction, the brushless motor 11 can be made compact in the radial direction.

(3) The number of magnetic poles of the rotating permanent magnets of the rotor 18 is four in the circumferential direction, and the first to fourth rotating permanent magnets 21 to 24 are used.
Are arranged adjacent to each other, and six projecting iron cores are formed.
Therefore, in the state where the rotor 51 can be effectively rotated, the simplest and well-arranged configuration can be obtained.

(4) First to sixth fixed permanent magnets 31 to 36
Are arranged so that their polarities change in the circumferential direction. Therefore, the first to sixth fixed permanent magnets 31 to 36 directly attract the first to fourth rotating permanent magnets 21 to 24 of the rotor 18 while the first to sixth coils L1 to L6 are not supplied with power. The action can be prevented, and the possibility of adversely affecting the rotor 18 can be reduced.

(5) Since the protruding iron core 27 and the connecting iron core 28 are integrally formed, the protruding iron core 27 and the connecting iron core 28 are formed.
The magnetic flux is easy to pass between and. (Second Embodiment) Next, a second embodiment will be described with reference to FIGS.
Follow the instructions below. This embodiment is largely different from the previous embodiment in that the rotor has a protrusion and no permanent magnet is attached to the rotor. The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 is a schematic sectional view of the brushless motor of the second embodiment, and FIG. 9 is a graph showing the relationship between the rotation angle of the rotor and the power feeding state of the coil. As shown in FIG. 6, the rotor 51 of this brushless motor is made of iron,
It is formed to have a plurality of protrusions radially. In this embodiment, the rotor 51 has four protrusions and is formed to have a cross shape in a cross shape. Of the protrusions, a protrusion extending to the upper left with respect to the rotation shaft 19 in FIG. 6 is referred to as a protrusion R1, and the protrusions R2 and R are sequentially arranged in the clockwise direction.
3, R4. Radial outer ends of the projections R1 to R4 are formed in an arc shape. Further, no permanent magnet is attached to the rotor 51.

The coil is wound in the same winding direction as the first to sixth coils L1 to L6 of the first embodiment. In this embodiment, the lower left coil in FIG.
A coil that is called "1" and that faces the coil u1 with the rotary shaft 19 interposed therebetween is called a coil u2. The winding of the coil u1 and the winding of the coil u2 are connected to each other to form a U phase. Further, the coil adjacent to the coil u2 in the clockwise direction is the coil v1, and the coil opposite thereto is the coil v2 and the coil v2.
A coil adjacent to the coil 2 on the clockwise side with respect to 2 is referred to as a coil w1, and a coil opposed thereto is referred to as a coil w2. Coil v1,
Windings are also connected to the v2 and the coils w1 and w2, respectively, and form a V phase and a W phase, respectively. In this way, the coils are formed so as to form three phases of U phase, V phase, and W phase.

The protrusions R1 to R4 are formed in the same size and shape. The circumferential width of each of the protrusions R1 to R4 is
The width of the connecting core 28 in the circumferential direction is substantially the same. Further, the width of each of the protrusions R1 to R4 in the circumferential direction is larger than the distance between the end faces of the adjacent connecting iron cores 28 in the circumferential direction.

In this brushless motor, a rotary light shield plate is attached so as to rotate integrally with the rotary shaft 19,
A plurality of sets of photoelectric elements and light sources are arranged via a bracket so as to sandwich the rotary light shielding plate. A cutout portion is formed in the rotary light shield plate, and the rotation position of the rotor is detected by switching the light receiving state and the light shield state of the photoelectric element by the rotation of the rotary light shield plate. The brushless motor is configured such that each of the U-phase to W-phase coils is fed with power as shown in the graph of FIG. 9, based on the rotational position of the rotor 51 detected by the photoelectric element. In this embodiment, when the projection R1 of the rotor 51 faces the coil w1 as shown in FIG. 6, the rotation angle of the rotor 51 is set to 0 °.

When the U-phase to W-phase coils are not supplied with power, the magnetic lines of force of the first to sixth fixed permanent magnets 31 to 36 are the same as those in the first embodiment. 27, a closed circuit that passes through the cylindrical portion 13a of the yoke 13 does not act on the rotor 51 side by the magnetic force of each magnet.

When the rotation angle θ of the rotor 51 is 0 °, the protrusion R1 of the rotor 51 faces the coil w1 and the protrusion R3 faces the coil w2. The protrusion R2 partially faces the connecting core 28 that covers the coil u2,
4 faces the connecting iron core 28, a part of which covers the coil u1. In this state, the U-phase, that is, the coil u1 and the coil u2 are supplied with electric power based on the fact that the rotation angle of the rotor 51 is detected by the photoelectric element.

By this power supply, the projection R4 is pulled toward the coil u1 by the strong magnetic force obtained by adding the magnetic force of the electromagnet by the coil u1 and the magnetic forces of the fourth and fifth fixed permanent magnets 34, 35. Further, the protrusion R2 is pulled toward the coil u2 by the strong magnetic force obtained by adding the magnetic force of the electromagnet by the coil u2 and the magnetic force of the first and second fixed permanent magnets 31, 32. Therefore, the rotor 51 rotates counterclockwise. Further, the magnetic force lines emitted from the N poles of the coil u1, the fourth and fifth fixed permanent magnets 34 and 35 pass through the connection iron core 28 and enter the protrusion R4, pass through the rotor 51, and then from the protrusion R2 to the connection iron core 28. Through the coil u2,
It enters the S poles of the first and second fixed permanent magnets 31, 32 (see FIG. 7).

When the rotation angle θ of the rotor 51 reaches 30 °, the protrusion R4 faces the coil u1 and the protrusion R2 faces the coil u2. In addition, a part of the protrusion R3 faces the connecting core 28 that covers the coil v1, and a part of the protrusion R1 is the coil v1.
It opposes the connecting core 28 that covers 2. Rotation angle θ is 30 °
When it is detected by the photoelectric element, the U phase is no longer supplied with power and the V phase is newly supplied with power.

By this power supply, the projection R3 is pulled toward the coil v1 by the magnetic force obtained by adding the magnetic force of the electromagnet by the coil v1 and the magnetic forces of the second and third fixed permanent magnets 32 and 33. Further, the projection R1 is pulled toward the coil v2 by the magnetic force of the sum of the magnetic force of the electromagnet by the coil v2 and the magnetic forces of the fifth and sixth fixed permanent magnets 35, 36. Therefore, the rotor 51 continues to rotate counterclockwise without stopping. In addition, the magnetic force lines emitted from the N poles of the coil v1, the second and third fixed permanent magnets 32 and 33 pass through the connecting iron core 28 and enter the protrusion R3, and the rotor 5
1 through the connection core 28, the coil v2, the S of the fifth and sixth fixed permanent magnets 35, 36.
Enter the pole (see FIG. 8 (a)).

Similarly, when the rotation angle of the rotor 51 reaches 60 °, the V phase is no longer supplied with power and the W phase is newly supplied with the rotor 51 being continuously rotated counterclockwise. The magnetic field lines emitted from the N poles of the coil w1 and the first and sixth fixed permanent magnets 31 and 36 pass through the connecting iron core 28, enter the protrusion R2, pass through the rotor 51, and pass through the connecting iron core 28 from the protrusion R4. Coil w2, third and fourth fixed permanent magnets 3
It enters the S poles of 3, 34 (see FIG. 8B).

When the rotation angle of the rotor 51 reaches 90 °, the W phase is no longer supplied with power and the U phase is supplied again.
The rotor 51 continues to rotate counterclockwise. In this way, as shown in the graph of FIG.
Each time it rotates, the U, V, and W-phase power supply is sequentially switched. Therefore, the rotor 51 includes the coils u1 to w2.
Magnetic force of the electromagnet and the first to sixth fixed permanent magnets 31 to 31.
The strong magnetic force, which is the sum of the 36 magnetic forces, causes continuous rotation.

According to this embodiment, in addition to the effects (2), (4) and (5) of the above embodiment, the following effects are obtained. (6) A hybrid magnet provided with a three-phase coil is attached to the stator, and the protrusion R1 is attached to the rotor 51.
~ R4 are formed. Therefore, the first to sixth fixed permanent magnets 3 are supplied by sequentially supplying power to the coils of the three phases.
The protrusions R1 to R4 can be attracted by the strong magnetic force obtained by adding the magnetic forces of the electromagnets 1 to 36 and the magnetic force of the electromagnet to rotate the rotor 51. Therefore, even in this case, it is possible to reduce the size and increase the torque.

(7) The circumferential widths of the projections R1 to R4 of the rotor 51 and the circumferential width of the connecting iron core 28 are formed to be substantially the same. Therefore, when the projections R1 to R4 are most pulled by the electromagnet, the projections R1 to R4 and the connecting iron core 28 face each other in the circumferential direction without any excess or deficiency. Therefore, leakage of magnetic flux between the protrusions R1 to R4 and the connecting iron core 28 is reduced, and high torque can be effectively achieved.

(8) The circumferential widths of the projections R1 to R4 of the rotor 51 are formed to be larger than the distance between the end faces of the adjacent connecting iron cores 28 in the circumferential direction. Therefore, the protrusion and the connecting core 28
By passing a magnetic flux through at least a part facing each other, a tensile force can be continuously exerted on the rotor 51, and the rotor 51 can be smoothly rotated.

(9) The number of the projections R1 to R4 of the rotor 51 is four, the projecting iron cores 27 of the stator are formed of six, and the coils are formed in three phases. The simplest way to make it rotatable,
The configuration can be arranged well.

(10) The coils u1, v1, w1 are wound so that the inner side in the radial direction becomes the N pole in the state of being fed with power.
The coils u2, v2, w2 facing each other are wound so that the inner side in the radial direction becomes the S pole in a state where power is supplied. Further, the rotor 51 is formed so that the protrusions face each other with the rotary shaft 19 interposed therebetween. Therefore, each coil u
The magnetic lines of force generated from 1, 1, v 1 and w 1 are the projections R of the rotor 51.
1, R3 or projections R2, R4 and enter coils u2, v2, w2, respectively. Therefore, the magnetic flux is easily passed. The embodiment is not limited to the above embodiment, and may be modified as follows, for example.

The protruding iron core 27 and the connecting iron core 28 are not limited to be integrally formed. For example, the protruding iron core 27 and the connecting iron core 28 are separately formed, and the central portion of the connecting iron core 28 is formed at the tip of the protruding iron core 27. May be in contact with each other.

In the first embodiment, the first to fourth rotary permanent magnets 21 to 24 are not limited to be formed adjacent to each other, and for example, the first to fourth rotary permanent magnets may be slightly adjacent to each other. You may form so that there may be a gap.

Hall element 4 in the first embodiment
The number 1 is not limited to one, and a plurality may be provided. The number of coils and fixed permanent magnets is not limited to six, and may be an even number other than 6, for example.
For example, the number may be two, four, eight, or the like.

In the first embodiment, the number of fixed permanent magnets attached to the rotor is not limited to four, and may be an even number other than 4, for example, 2
The number may be 6, 6, 8 or the like.

In the second embodiment, the number of protrusions of the rotor is not limited to four, and may be an even number other than 4, for example, 2, 6, 8 or the like. Good.

In the first embodiment, the coil is the first
It is not limited to rotating the rotor 51 counterclockwise by supplying power to the coil L1, the second coil L2, the third coil L3, ... For example, when power is supplied to the fourth and fifth coils L4 and L5 in the state of θ = 0 °, the radially inner side of the fourth coil L4 becomes the N pole and the radially inner side of the fifth coil L5 becomes the S pole. , And the pulling force and the repulsive force respectively act on the S2 pole of the rotor 18, the rotor 18 rotates in the clockwise direction. Next, when rotating by 30 °, power supply to the fifth coil L5 is stopped, power is continuously supplied to the fourth coil L4, and power is newly supplied to the third coil L3, so that between the N2 pole and the third coil L3. Since the repulsive force acts and the tensile force acts between the N2 pole and the fourth coil L4, the rotor 1
8 continues to rotate clockwise. In this way, the rotor 18 may be rotated clockwise by supplying power to the sixth coil L6, the fifth coil L5, the fourth coil L4, the third coil L3, ...

In the second embodiment, the coil is U
Power is not supplied to the rotor 51 in the order of the phase, the V phase, and the W phase to rotate the rotor 51 counterclockwise. For example, θ = 0 °
In this state, when power is supplied to the V-phase coil, the protrusion R
2 and R4 are pulled toward the coils v1 and v2, respectively, so that the rotor 51 rotates clockwise. Next, 30 °
When the U-phase and the W-phase are supplied in this order for each rotation, the rotor 5
1 continues to rotate clockwise. Therefore, the coils may be supplied with power in the order of W phase, V phase, and U phase to rotate the rotor 51 clockwise. In this case, if the W phase and the U phase are newly called U phase and W phase, respectively, U phase, V phase, and W phase
Power is supplied in the order of phases to rotate the rotor 51 clockwise.

In the first and second embodiments, the rotor position may be detected by, for example, a rotary encoder. -In the second embodiment, the position of the rotor 51 is detected by
It is not limited to the combination of the rotary light shield plate and the photoelectric element. For example, a light source is attached to one of the end frame 14 and the bottom of the yoke 13, and a photoelectric element is attached to the other, and when the protrusions R1 to R4 are located between the light source and the photoelectric element due to the rotation of the rotor 51, the light blocking state is obtained. Therefore, when the gap between the protrusions R1 to R4 is positioned, the light receiving state is set. A plurality of sets of the light source and the photoelectric element may be attached so that the position of the rotor 51 can be detected.

In the first embodiment, the position of the rotor 18 is detected by a combination of a rotary light shielding plate and a photoelectric element, as in the second embodiment, for example. Good.

In the second embodiment, the rotor 51
Is not limited to being made of iron, and may be made of another ferromagnetic material, for example. In the first embodiment, the rotor core 20 is not limited to being made of iron, but may be made of another ferromagnetic material, for example.

The brushless motor is not limited to the inner rotor type, but may be, for example, the outer rotor type.
The technical ideas that can be understood from the above embodiments will be added below.

(1) In the invention described in claim 1 or 2, the permanent magnets attached to the rotor are provided adjacent to each other in the circumferential direction. (2) In the invention according to any one of claims 1, 2 and (1), the protruding core and the connecting core are integrally formed.

(3) In the invention described in any one of claims 3 to 6, the rotor is made of iron.

[0089]

As described above in detail, according to the inventions of claims 1 to 6, it is possible to achieve a small size and a high torque and a compact size in the radial direction.

[Brief description of drawings]

FIG. 1A is a schematic cross-sectional view of a brushless motor,
(B) is a partial cross-sectional schematic side view taken along line IB-IB in (a).

FIG. 2 is a schematic cross-sectional view showing the operation.

FIG. 3 is a schematic cross-sectional view showing the action.

FIG. 4 is a schematic cross-sectional view showing the operation.

FIG. 5 is a graph showing a relationship between a rotation angle of a rotor and a power feeding state of a coil.

FIG. 6 is a schematic cross-sectional view of a brushless motor according to a second embodiment.

FIG. 7 is a schematic cross-sectional view showing the operation.

FIG. 8 is a schematic cross-sectional view showing the operation.

FIG. 9 is a graph showing a relationship between a rotation angle of a rotor and a power feeding state of a coil.

FIG. 10 is a schematic view showing a conventional hybrid magnet.

[Explanation of symbols]

11 ... Brushless motor, 18, 51 ... Rotor 21,
24 ... 1st-4th rotation permanent magnets, R1-R4 ... protrusions, 1
2 ... Motor housing constituting stator, 13a ... Cylindrical portion constituting hybrid magnet, 27 ... Similarly projecting iron core, 28 ... Similarly connecting iron core, 31-36 ... Similarly, first-first
Sixth fixed permanent magnets, L1 to L6 ... Similarly, first to sixth coils, u1 to w2.

Claims (6)

[Claims] 1. A rotor in which a plurality of permanent magnets magnetized so as to change the polarity in the radial direction are arranged in the circumferential direction so that adjacent magnetic poles are different, and one of the rotor and the outer peripheral surface or the inner peripheral surface. Are opposed to each other, a fixed core provided in a circumferential direction on a surface of the cylindrical part facing the rotor, and a coil wound around the fixed core and sequentially fed so that the rotor rotates. A brushless motor including a stator including a hybrid magnet including a fixed permanent magnet arranged so as to change polarity in the circumferential direction between the fixed iron cores, wherein the fixed iron core has a base end A projecting core that is connected to a cylindrical portion and has a tip projecting toward the rotor and around which the coil is wound, and a protruding U-shaped core that covers the coil and has an end portion that is the cylindrical portion. Paired with Consisting of a connecting iron core, an end portion of the connecting iron core is magnetically insulated from the cylindrical portion, the fixed permanent magnets, at both ends thereof, contact the adjacent connecting iron cores, the adjacent fixed permanent magnets are , A brushless motor, wherein the same magnetic poles are arranged so as to face each other. 2. The brushless motor according to claim 1, wherein the number of magnetic poles of the permanent magnets of the rotor is four in the circumferential direction, and the number of the projecting iron cores is six. 3. A rotor having a plurality of radial projections, a cylindrical portion facing one of the outer peripheral surface and the inner peripheral surface of the rotor, and a plurality of circumferentially provided surfaces of the cylindrical portion facing the rotor. A fixed iron core, a coil wound around the fixed iron core and sequentially fed with power so that the rotor rotates, and a fixed permanent magnet arranged between the fixed iron cores so that the polarity changes in the circumferential direction. And a stator provided with a hybrid magnet, wherein the fixed iron core is formed such that a base end thereof is connected to the cylindrical portion and a tip thereof projects toward the rotor, and the coil is wound. A protruding core that is mounted and a connecting iron core that is formed in a substantially U shape and covers the coil and has an end portion facing the cylindrical portion, and the end portion of the connecting iron core is magnetically insulated from the cylindrical portion. The brushless motor, wherein the fixed permanent magnets are in contact with the adjacent connection cores at both ends thereof, and the adjacent fixed permanent magnets are arranged such that the same magnetic poles face each other. 4. The brushless motor according to claim 3, wherein a circumferential width of the protrusion of the rotor and a circumferential width of the connecting iron core are substantially the same. 5. The brushless motor according to claim 3, wherein the circumferential width of the protrusion of the rotor is larger than the distance between the end faces of the adjacent connecting iron cores in the circumferential direction. 6. The rotor has four protrusions in the circumferential direction and six protrusion iron cores, and the coils wound around the protrusion iron cores have three phases in which the protrusion iron cores facing each other by 180 ° are fed simultaneously. It is a coil, It is characterized by the above-mentioned.
The brushless motor according to claim 1.