JP2002174239A - Magnetic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic bearing device capable of enhancing energy efficiency and outputting stable and strong attractive force. SOLUTION: In this magnetic bearing device, magnetic attraction members 8 and 16 are provided with permanent magnets 5 and 13, yokes 1 and 11 which are joined to and both pole end faces of the permanent magnets 5 and 16, are provided with a closed magnetic path so as to be formable between the permanent magnets 5 and 16, and form magnetic attraction surfaces on surfaces facing to the attraction members 7 and 15 with the arranged permanent magnets 5 and 16 and exciting coils 6 and 14 provided on the yokes 1 and 11. When the exciting coils 6 and 14 are energized so as to form magnetic paths in a direction for canceling the magnetic paths formed within the yokes 1 and 11 by the permanent magnets 5 and 13, the magnetic attraction members 8 and 16 generate attraction force of the attracting members 7 and 15 by forming the magnetic path among the magnetic attraction surfaces and the attracting members 7 and 15 via a gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic bearing device, and more particularly, to a bearing device for an electric motor using a hybrid electromagnet called a basic factor.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing the structure of a general rotary motor. Referring to FIG. 3, electric motor 100 includes a rotor housed in case 101 and a stator arranged around the rotor. The rotor includes an iron core 102 arranged around a rotation shaft 103 and a coil 104 wound therearound. Also, the iron core 10 of the rotating shaft 103
A plurality of commutators 107 connected to the coil 104 are provided in a portion adjacent to the coil 2 in a circumferential direction.

[0003] The stator is a case 10 around an iron core 102.
1 is provided with a magnet 105 provided inside.

[0004] Both ends of the rotating shaft 103 are rotatably supported by bearings 108, 108 provided at the end of the case 101, respectively.

In the case 101, a commutator 107 is provided.
Brushes 106 serving as contacts for supplying DC power to the power supply are provided.

Therefore, in the conventional motor, the brush noise and the rotating shaft are supported while being in contact with the bearing using a ball bearing, an oilless metal or the like. There was a problem that could not be avoided.

In a conventional motor, the bearing 10
In No. 8, there is a problem that the use of lubricating oil also affects environmental pollution, wear during high-speed rotation, and life.

As a solution to this problem, there has been proposed a bearing having a non-contact structure using magnetic energy for supporting a rotating shaft of the brushless motor, using a brushless motor.

FIG. 4 is a sectional view showing a magnetic bearing of a conventional electric motor. As shown in FIG.
A magnetic bearing device 110 is provided at one end of the rotating shaft.

The brushless motor 30 includes a rotor 32 composed of a magnet disposed around a rotating shaft 32, and a drive coil 33 and a yoke 34 disposed around the rotor 32. The brushless motor 30 rotates by applying a rotating magnetic field to the rotor 32 from a drive coil.

The magnetic bearing device 110 includes a rotating shaft 32.
A rotating part 111 composed of a permanent magnet disposed around
And a fixing portion 113 to which another row of permanent magnets 112 arranged around the rotating portion 111 via a gap 114 is fixed.

[0012]

The conventional brushless motor 30 described above does not generate sound, while the magnetic bearing device 1
Since the brushless motor 10 is non-contact, it has an advantage that almost no sound is generated while the brushless motor 30 is rotating.

However, the above-described magnetic bearing device 110 of the brushless motor 30 is a non-contact bearing formed of only permanent magnets by magnetic attraction and magnetic repulsion, and tends to cause imbalance in magnetic force, which is not practical. There was a problem.

A magnetic bearing device using an electromagnet is conceivable. However, the magnetic force must be controlled automatically. If the magnetic attraction force and the magnetic repulsion force of the electromagnet are small, a large amount of electric power is required. In other words, there were restrictions on energy conservation.

Accordingly, a first technical object of the present invention is to provide a magnetic bearing device capable of enhancing energy efficiency and outputting a stable and strong attractive force.

A second technical object of the present invention is to provide a magnetic bearing device having a magnetic thrust bearing.

A third technical object of the present invention is to provide a magnetic bearing device having a magnetic radial bearing.

[0018]

According to the present invention, there is provided a column-shaped suction member including a disk disposed around a rotation shaft, and the suction member being sandwiched between the rotation shaft and the suction member. A magnetic bearing device comprising: at least a pair of magnetic attraction members each having a magnetic attraction surface opposed to each other with a gap between the magnetic attraction member and a permanent magnet; Along with being joined to both extreme surfaces, and provided so as to be able to form a closed magnetic path between the permanent magnet and
A yoke that forms the magnetic attraction surface on a surface facing the attraction member on which the permanent magnet is disposed; and an excitation coil provided on the yoke, wherein the excitation coil has the permanent magnet in the yoke. When current is applied to form a magnetic path in a direction to cancel the magnetic path to be formed, the magnetic path is formed through the gap between the magnetic attraction surface and the attraction member to form the at least one pair of magnetic attraction. A magnetic bearing device is obtained, wherein the member generates a suction force of the suction member.

According to the present invention, in the magnetic bearing device, the attraction member has a disk shape provided coaxially with a rotating shaft, and the pair of yokes of the at least one pair of magnetic attraction members are A magnetic bearing device is provided, wherein each has a cylindrical shape, and each of the magnetic attraction surfaces constitutes a magnetic thrust bearing portion arranged to face both end surfaces of the attraction member.

According to the present invention, in the magnetic bearing device, each of the yokes includes a hollow portion of a ring that draws a circle about the rotation axis, and each of the exciting coils includes the hollow portion. A magnetic bearing device having a ring shape mounted in the hollow portion is obtained.

Further, according to the present invention, in the magnetic bearing device, the attraction member has a columnar shape provided coaxially with the rotating shaft, and the at least one pair of magnetic attraction members is such that the yoke is the attraction member. The magnetic bearing device is characterized in that the magnetic bearing device has a rectangular plate-shaped magnetic radial bearing portion provided with the magnetic attraction surface in a direction along the generatrix of the outer peripheral surface of the magnetic bearing device.

Further, according to the present invention, in the magnetic bearing device, the yoke has a plurality of through holes provided in a line in the axial direction, and the exciting coil penetrates through the through holes to form the yoke. The side provided with the magnetic attraction surface is:
A magnetic bearing device is provided, which is provided on the opposite side in the radial direction.

Further, according to the present invention, in the magnetic bearing device, a plurality of the yokes are provided along the outer peripheral surface of the column at equal angular intervals with respect to the central axis. Is obtained.

According to the present invention, in the magnetic bearing device, a plurality of the attraction members are provided, and a first attraction member among the attraction members has a disk shape provided coaxially with a rotating shaft. The at least one pair of magnetic attraction members has at least two pairs, and one of the magnetic attraction members has a cylindrical shape in each of the yokes, and each of the magnetic attraction surfaces has both end surfaces of the first attraction member. A magnetic thrust bearing portion disposed opposite to the second member, wherein the second attraction member of the attraction members has a cylindrical shape provided coaxially with the rotation axis, and the remaining pair of the attraction members The magnetic bearing device is characterized in that the yoke constitutes a square plate-shaped magnetic radial bearing portion provided with the magnetic attraction surface in a direction along a generatrix of an outer peripheral surface of the second attraction member. can get.

According to the present invention, in the magnetic bearing device, each of the yokes in the magnetic thrust bearing portion includes a hollow portion of a ring that draws a circle around the rotation shaft. A magnetic bearing device is obtained, wherein each of the exciting coils has a ring shape attached to the hollow portion.

According to the invention, in any one of the magnetic bearing devices, the yoke in the magnetic radial portion includes a plurality of through holes provided in the axial direction, and the exciting coil includes the through hole. A magnetic bearing device is provided in which the yoke is provided on the opposite side of the yoke in the radial direction from the side on which the magnetic attraction surface is provided.

Further, according to the present invention, in the magnetic bearing device, a plurality of the yokes in the magnetic radial portion are provided along the outer peripheral surface of the column at equal angular intervals with respect to the central axis. Thus, a magnetic bearing device is obtained.

[0028]

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

FIG. 1 is a sectional view showing a magnetic bearing device according to an embodiment of the present invention. FIG. 2 is a partially cutaway perspective view of the magnetic bearing device of FIG. In FIG. 1, a magnetic thrust bearing 10 and a radial magnetic bearing 20 as magnetic bearing devices are provided on a rotating shaft 31 of a brushless motor 30 so as to be arranged side by side in the longitudinal direction of the rotating shaft.

The brushless motor 30 includes a rotor 32 having a magnet around a rotating shaft 31, a coil 33 and a yoke 34 as a stator arranged around the rotor 32, as described in the prior art. It has.

The magnetic thrust bearing portion 10 is opposed to an adsorbing member (first adsorbing member) 7 made of a disk-shaped soft magnetic material disposed around the rotating shaft 31 in the axial direction via the adsorbing member 7. And a pair of magnetic attraction members 8 and 8 provided.

Each magnetic attraction member 8, 8 is formed of a soft magnetic material having a depression 3 in the center, a through hole 4 penetrating the depression 3, and a hollow portion 1b provided in the circumferential direction. The yoke 1 has a columnar shape. The yokes 1, 1
A ring-shaped groove 2 extending from the opposite end surface to the hollow portion 1b is provided. A ring-shaped permanent magnet 5 is mounted in the groove 2.

In the illustrated example, each of the permanent magnets 5 is mounted such that its outer peripheral surface is an S pole and its inner peripheral surface is an N pole.

In the hollow portion 1b, a conductive wire is inserted.
Exciting coil 6 wound in a ring around the central axis of
Is provided.

On the other hand, the magnetic radial bearing portion 20 includes a columnar suction member (second suction member) 15 provided around the rotation shaft 31 and a plate-like magnetic suction member 1 elongated in the rotation shaft direction.
6 is provided. The four magnetic attraction members 16 are formed at 90 degrees to each other around the axis, and are fixed by a fixing member (not shown) so as to maintain their positions. Further, the magnetic attraction member 16 includes the yokes 11, and each of the yokes 11 has a structure formed by integrally forming two yoke pieces 11a in a paired end face. The yoke piece 11a has a square plate shape having a square through hole 11b at the center and a groove 12 extending from the surface facing the rotation shaft 31 to the through hole 11b.

Each groove 12 has a prismatic permanent magnet 13
Are mounted such that end faces adjacent in the direction of the rotation shaft 31 have magnetic poles of the same polarity. Here, in the illustrated example, the end face near the outer surface in the direction of the rotation shaft 31 is S
The pole and the inner end face in the direction of the rotation axis 31 are N poles.

Further, the through holes 11 of each yoke piece 11a
b through the outside of the yoke piece 11a,
An exciting coil 14 composed of a wound conductive wire is wound and mounted so as to pass through the through hole 11b of the yoke piece 11a.

Next, the operation of the magnetic bearing device according to the embodiment of the present invention will be described.

First, the magnetic thrust bearing 10 will be described.

Referring again to FIG. 1, in the magnetic thrust bearing portion 10, when the excitation coil 6 is not energized, the permanent magnet 5 is bent toward the center axis of the yoke 1 from the N pole, and is bent outward. A magnetic path is formed that bends at a position closer to the outer end face, turns outward in the radial direction, turns toward the inner end face in the axial direction, and turns at a position closer to the inner end face, turns inward in the radial direction, and enters the S pole of the permanent magnet 5. Is done. At this time, when a DC current is applied to the exciting coil 6 so as to form a magnetic path in a direction to cancel the magnetic path formed by the permanent magnet 5, the magnetic flux from the permanent magnet 5 is applied to the N pole of the yokes 1, 1. It jumps out from the end faces adjacent to each other and enters the opposing face of the adsorption member 7 made of a soft magnetic material.
The radially outward direction of the attraction member 7 and the permanent magnet 5
A magnetic path is formed that jumps out toward the end face of the yoke 1 near the S pole, enters the yoke 1 from this end face, and reaches the S pole of the permanent magnet 5. Here, the surface formed by the end surface of the yoke 1 adjacent to the permanent magnet is referred to as a magnetic attraction surface.
Therefore, the end surface of the attraction member 7 is strongly attracted to the magnetic attraction surface which is the facing surface on the yoke 1 side. Similarly, the other magnetic attraction member strongly attracts the attraction member 7 at the magnetic attraction surface, so that the attraction member 7 receives an equal attraction force from each of the magnetic attraction members. It stops at the position in the direction. Therefore, the attraction member keeps rotating in a non-contact state with a predetermined gap from the magnetic attraction surface of the yoke 1 on the opposing surface.

Next, the operation of the magnetic radial bearing 20 will be described.

In the magnetic radial bearing portion 20, when the excitation coil 14 is not energized, the yoke 11 has the respective N-poles of the permanent magnets 13 directed toward the central axis, bent, and directed radially outward. At the position closer to the outer end face, it bends, faces outward in the axial direction, moves along the outer face toward the outer end face, turns at the position closer to the outer end face, turns inward in the radial direction, and bends at the position closer to the inner face, A magnetic path is formed that moves axially inward along the side surface and enters the S pole of the permanent magnet 13. At this time, when a direct current is applied to the exciting coil 14 so as to form a magnetic path in a direction to cancel the magnetic path formed by the permanent magnet 13, the magnetic flux from the permanent magnet 13 causes N The side surface of the yoke piece 11a which protrudes from the inner surface on the pole side, enters the opposite side surface of the cylindrical attracting member 15 made of a soft magnetic material, and faces outward in the axial direction of the attracting member 15 and is connected to the S pole of the permanent magnet. A magnetic path is formed such that the magnetic path protrudes from the side surface portion of the suction member 15 opposing to the side surface of the yoke piece 11a, enters the yoke piece 11a from this side surface, and reaches the S pole.

Therefore, the side surface of the attraction member 15 is strongly attracted to the side surface of the yoke 11 (hereinafter referred to as the magnetic attraction surface) adjacent to the portion where the permanent magnets 13 are joined. Similarly, the other opposing magnetic attraction members 16 also attract the side surface of the attraction member 15, so that the attraction members 16 receive the same attraction force from the respective magnetic attraction members 16, so that the attraction forces are balanced with each other. At a position in the direction perpendicular to the direction,
The state is stopped with a gap with respect to the magnetic attraction surface.
Therefore, the side surface of the attraction member 15 keeps rotating with the rotating shaft 31 in a non-contact state with a predetermined gap from the always facing magnetic attraction surface.

The magnetic bearing device according to the embodiment of the present invention described above includes a magnetic thrust bearing portion 10 and a magnetic radial bearing portion 20, and the magnetic thrust bearing portion 10 and the magnetic radial bearing portion 20 are attracted by the magnitude of the current flowing through each of the exciting coils 6 and 14. Since the force can be controlled, it is possible to provide a magnetic bearing device that can provide stable rotation to the rotating shaft 31 and can provide more stable rotation with small energy in a non-contact state because of high energy efficiency.

[0045]

As described above, according to the present invention,
Since the energy efficiency can be increased and a stable strong suction force can be output, it is possible to provide a magnetic bearing device including a magnetic and magnetic thrust bearing portion, a magnetic radial bearing portion, and the like that can constantly maintain stable rotation in a non-contact state. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a magnetic bearing device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the magnetic bearing device of FIG. 1;

FIG. 3 is a cross-sectional view illustrating a rotary motor according to the related art.

FIG. 4 is a sectional view showing a schematic structure of a conventional brushless motor and a magnetic bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Yoke 1b Hollow part 2 Groove 3 Depression 4 Through hole 5 Permanent magnet 6 Exciting coil 7 (First) adsorption member 8 Magnetic attraction member 10 Magnetic thrust bearing part 11 Yoke 11a Yoke piece 11b Through hole 12 Groove 13 Permanent magnet 14 Excitation Coil 15 Attraction member 16 Magnetic attraction member 20 Magnetic radial bearing unit 30 Brushless motor 31 Rotary shaft 32 Rotor 33 Exciting coil 34 Yoke 100 Electric motor (Rotary motor) 101 Case 102 Iron core 103 Rotating shaft 104 Coil 105 Magnet 106 Brush 107 Commutator 108 Bearing 110 Magnetic bearing device 111 Rotating part 112 Permanent magnet 113 Fixed part 114 Gap

 ──────────────────────────────────────────────────続 き Continuing from the front page (71) Applicant 500456899 Environmental city consulting Co., Ltd. 6302 Tamura, Hiratsuka-shi, Kanagawa (72) Inventor Sanshiro Ogino 2-20-1 Futaba 2-chome, Shinagawa-ku, Tokyo 405 (72 Inventor Yasumi Ochiai 306-32-2-306 Takaishi, Aso-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Yoshitake Nishi 2-39-7, Daizawa, Setagaya-ku, Tokyo (72) Inventor Kazuya Oguri, Sagamihara City, Kanagawa Prefecture 5-6-1 Kamizuruma Rene Higashi Rinkan A-111 (72) Inventor Tetsu Nakatsuka 2-31-3 Takamori, Isehara-shi, Kanagawa F term (reference) 3J102 AA01 BA03 BA19 CA10 DA02 DA03 DA09 DA16 DA27 GA13 5H607 BB01 BB01 BB14 GG01 GG19

Claims (10)

[Claims] 1. A gap between a columnar suction member including a disk disposed around a rotation axis and the suction member so as to sandwich the suction member around the rotation shaft and sandwich the suction member. A magnetic bearing device comprising at least a pair of magnetic attraction members each having a magnetic attraction surface opposed to each other, wherein the magnetic attraction member is joined to a permanent magnet and both extreme surfaces of the permanent magnet, And a yoke that forms the magnetic attraction surface on a surface facing the attraction member on which the permanent magnet is arranged, and an excitation coil provided at the yoke. When the excitation coil is energized so as to form a magnetic path in a direction to cancel a magnetic path formed in the yoke by the permanent magnet, the gap is provided between the magnetic attraction surface and the attraction member through the gap. The magnetic path The at least one pair of magnetic attraction members by forming a magnetic bearing apparatus characterized by generating a suction force of the suction member. 2. The magnetic bearing device according to claim 1, wherein
The attraction member has a disk shape provided coaxially with a rotation axis, a pair of the yokes of the at least one pair of magnetic attraction members each have a cylindrical shape, and each of the magnetic attraction surfaces is the attraction member. A magnetic thrust bearing portion disposed opposite to both end faces of the magnetic thrust bearing portion. 3. The magnetic bearing device according to claim 2, wherein
Each of the yokes includes a hollow portion of a ring that draws a circle about the rotation axis, and each of the exciting coils has a ring shape attached to the hollow portion. Magnetic bearing device. 4. The magnetic bearing device according to claim 1, wherein
The attraction member has a columnar shape provided coaxially with the rotation axis, and the at least one pair of magnetic attraction members has a square shape in which the yoke has the magnetic attraction surface in a direction along a generatrix of an outer peripheral surface of the attraction member. A magnetic bearing device comprising a plate-shaped magnetic radial bearing portion. 5. The magnetic bearing device according to claim 4, wherein
The yoke includes a plurality of through holes provided in a line in the axial direction, and the exciting coil passes through the through hole, and is opposite to a side of the yoke where the magnetic attraction surface is provided in a radial direction. A magnetic bearing device provided in a magnetic bearing device. 6. The magnetic bearing device according to claim 5, wherein
The magnetic bearing device, wherein a plurality of the yokes are provided along the outer peripheral surface of the column at equal angular intervals with respect to the central axis. 7. The magnetic bearing device according to claim 1, wherein
A plurality of the attraction members; a first attraction member of the attraction members having a disk shape provided coaxially with a rotation axis; at least a pair of magnetic attraction members, at least two pairs; A pair of members each constitute a magnetic thrust bearing portion in which each of the yokes has a cylindrical shape and each of the magnetic attraction surfaces is disposed opposite to both end surfaces of the first attraction member. The second attraction member has a columnar shape provided coaxially with the rotation axis, and the remaining pair of the magnetic attraction members has the yoke on a bus bar on the outer peripheral surface of the second attraction member. A magnetic bearing device comprising a rectangular radial magnetic bearing portion provided with the magnetic attraction surface in a direction along the magnetic bearing surface. 8. The magnetic bearing device according to claim 7, wherein
Each of the yokes in the magnetic thrust bearing portion,
A magnetic bearing device, comprising: a hollow portion of a ring that draws a circle about the rotation axis; and each of the exciting coils has a ring shape attached to the hollow portion. 9. The magnetic bearing device according to claim 7, wherein the yoke in the magnetic radial portion includes a plurality of through holes provided in the axial direction, and the exciting coil passes through the through hole. A magnetic bearing device, wherein the yoke is provided on a side opposite to a side where the magnetic attraction surface is provided in a radial direction. 10. The magnetic bearing device according to claim 9, wherein a plurality of the yokes in the magnetic radial portion are provided along the outer peripheral surface of the cylinder so as to be equiangularly spaced from the center axis. A magnetic bearing device, characterized in that: