JP2002122139A - Thrust magnetic bearing and flywheel battery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an iron core for electromagnet and reduce the weight thereof, and to enlarge a coil housing volume without reducing a necessary magnetic path area. SOLUTION: In a thrust magnetic bearing for supporting a rotor without contact therewith, resisting the axial directional thrust, thickness of an iron core 42 for electromagnet is formed so as to be gradually reduced toward outside in the radial direction. Namely, inner surfaces 53A and 52aA of a back side magnetic path 53 and an inward magnetic path 52a are respectively formed into a tapered surface coming closer to outer surfaces 53A and 52aB as they are directed toward outside in the radial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust magnetic bearing for supporting a rotating body in a non-contact manner against an axial thrust.

[0002]

2. Description of the Related Art As a bearing for supporting a rotating body in a non-contact manner against an axial thrust, for example, a thrust magnetic bearing disclosed in JP-A-6-159364 and JP-A-8-128445 is known. ing. As shown in FIG. 8, a collar 2 projecting radially outward is fixed to the rotating body 1 supported in a non-contact manner.
The above-described thrust magnetic bearing is constituted by the stator 3 arranged so as to be opposed to the above.

[0003] The stator 3 comprises a coil 4 for an annular electromagnet.
And an electromagnet core 5 having a shape surrounding the annular electromagnet coil 4. The one-sided cross-sectional shape of the electromagnet iron core 5 is as shown in the enlarged cross-sectional view of FIG. 9, and the coil housing space in the iron core has an inner surface y perpendicular to the axis O.
1, y2 and a rectangular section surrounded by parallel inner surfaces x1, x2.

In FIG. 9, symbols A1,..., B3 indicate the thickness of each magnetic path portion, and A1> B1, A2 (=
A1)> B2, A2 = A3, B2 = B3. This is considered as a cross section perpendicular to the magnetic path, and each cross section is denoted by A1,
.., B3 with a suffix S, SA1 = SB1 =
The relationship of SA2 = SB2 = SA4 = SB4 holds. Here, when expressed as SA1 = SB1 = SA2 = SB2 = SA4 = SB4 = S, the relations of S <SA3 and S <SB3 also hold.

[0005]

Generally, the iron core 5 for the electromagnet of the thrust magnetic bearing only needs to secure a minimum required magnetic path area. However, in the thrust magnetic bearing configured as described above, the diameter is small. Since the thickness of the magnetic path portions 5a and 5b along the direction is uniform in the radial direction (A2 = A3, B2 = B3),
The structure has a structure in which the magnetic path area gradually increases as going outward in the radial direction (SA2 <SA3, SB2 <SB3), and there are many wasteful portions that merely reduce the magnetic flux density.

The present invention has been made in view of such circumstances, and has as its object to reduce iron loss by reducing the size and weight of an iron core for an electromagnet without reducing the required magnetic path area. Alternatively, the copper loss can be reduced by increasing the coil storage volume, and the efficiency can be improved accordingly.

[0007]

Means for Solving the Problems In order to solve the above problems, the present invention employs the following means. According to the first aspect of the present invention, a collar (for example, an embodiment) provided on a rotating body to be supported (for example, the rotor portion 21 of the flywheel 12 in the embodiment) and protruding radially outward of the rotating body. And a stator (for example, a stator 32 in the embodiment) that supports the collar in a non-contact manner against an axial thrust acting on the rotating body, and the stator is for an annular electromagnet. Coil (for example, annular electromagnet coil 41 in the embodiment)
And an iron core for an electromagnet having a shape surrounding the coil for an annular electromagnet (for example, the iron core for an electromagnet 4 in the embodiment).
In the thrust magnetic bearing (2) (for example, the thrust magnetic bearing 15 in the embodiment), the thickness of the iron core for the electromagnet gradually decreases as it goes radially outward.

According to such a configuration, the thickness of the electromagnet iron core can be reduced without reducing the required magnetic path area. Also,
If the thickness is set such that the magnetic path area of the electromagnet iron core is constant at any position in the radial direction, the thickness is not wasted and the magnetic flux density becomes uniform.

According to a second aspect of the present invention, there is provided the magnetic bearing stator according to the first aspect, wherein the inner surface of the electromagnet iron core (for example, the inner surface 5 of the back magnetic path portion 53 in the embodiment) is provided.
3A, the inner surface 52aA of the inward magnetic path portion 52a) has an outer surface (for example, the outer surface 53B of the back magnetic path portion 53 and the outer surface 5 of the inward magnetic path portion 52a in the embodiment).
2aB).

According to such a configuration, when the outer diameter of the iron core for the electromagnet is made to be the same as the conventional one, there is a margin in the coil storage volume by the reduced thickness, so that the number of turns is increased or the wire diameter is increased. it can. Conversely, when the coil storage volume is made conventional, the outer diameter of the electromagnet iron core can be reduced while the number of turns and the wire diameter are made conventional.

According to a third aspect of the present invention, there is provided a flywheel battery device for converting rotational energy stored in a flywheel into electric energy and supplying the electric energy to the outside, wherein an axial thrust acting on the flywheel is provided. Alternatively, it is supported by the thrust magnetic bearing according to claim 2.

According to such a configuration, the size and weight of the iron core for the electromagnet or the provision of the thrust magnetic bearing having an enlarged coil storage volume are provided, so that the flywheel battery device itself is reduced in size and weight, or The allowable value of the axial thrust that can be supported without contact is improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the entire configuration of the flywheel battery device. This flywheel battery device includes a flywheel 12, an electric / generator 13, a radial magnetic bearing 1 in a vacuum vessel 11.
4, a thrust magnetic bearing 15 is provided.

The flywheel 12 is supported in a non-contact manner by a radial magnetic bearing 14 in a radial direction (radial direction) and by a thrust magnetic bearing 15 in an axial direction (thrust direction). Since a known radial magnetic bearing is used for the radial magnetic bearing 14, the description thereof is omitted here, and the thrust magnetic bearing 1 is omitted.
5 will be described later.

The electric / generator 13 includes a flywheel 12
And a stator section 22 provided around the rotor section 21. The generator operates as a motor while receiving electric power from the outside, and as a generator for supplying regenerative electric power to the outside. Operate.

As shown in FIG. 2, the thrust magnetic bearing 15 has a collar 31 fixed to the rotor portion 21 of the flywheel 12 and protruding radially outward, and a shaft acting on the flywheel 12 by attaching the collar 31 to the flywheel 12. A stator 32 which is supported in a non-contact manner against a directional thrust (thrust force),
The stator 32 includes an annular electromagnet coil 41 and an electromagnet iron core 42.

As shown in FIGS. 3 and 4, the electromagnet iron core 42 has a shape surrounding the annular electromagnet coil 41, and each end face on the side facing the collar 31 has an inner magnetic pole 51A. And inner magnetic path portion 5 forming outer magnetic pole 52A
1 and an outer magnetic path section 52, and a back magnetic path section 53 located on the opposite side of the collar 31. The outer magnetic pole 52A is brought closer to the inner magnetic pole 51a by an inward magnetic path portion 52a extending radially inward.

The thickness of the electromagnet core 42 is set differently for the inner magnetic path 51, the outer magnetic path 52, and the back magnetic path 53. The back side magnetic path portion 53 and the inward magnetic path portion 52a extending in the radial direction are formed so that the thickness gradually decreases as going outward in the radial direction, that is, as the distance from the axis O increases.

That is, the back magnetic path 53 and the inward magnetic path 52
The inner surfaces 53A, 52aA of a are tapered such that they gradually approach the outer surfaces 53B, 52aB of the back magnetic path portion 53 and the inward magnetic path portion 52a as going radially outward. Hereinafter, the thickness of each part will be described in detail with reference to FIG. 5 and in comparison with the conventional example shown in FIG.

In FIG. 5, the thicknesses A1, A2, A4, B1, B2,
B4 is set the same as the electromagnet core according to the conventional example shown in FIG. 9, but the thicknesses A3 'and B3' are set smaller than the thicknesses A3 and B3 in FIG. . Furthermore, thickness A
3 ', B3' are the magnetic path areas SA3 ', S
B3 'is set so as to satisfy SA2 = SA3' and SB2 = SB3 '.

Thus, in the magnet core 42 for an electromagnet according to the present embodiment, the magnetic path area in each cross section is determined by SA1 = SA2 = SA4 = SB1 = SB2 = SB4 = SA
The relationship of 3 '= SB3' is established, the wall thickness is not wasted, and the magnetic flux density in the iron core is uniform.

As described above, in the present embodiment, the inner surface 53 of the back magnetic path portion 53 and the inward magnetic path portion 52a is provided.
A, 52aA is a tapered surface that gradually approaches each outer surface 53B, 52aB as going outward in the radial direction, so that the electromagnet can be used without reducing the required magnetic path area, that is, without deteriorating the performance. A useless portion (reference symbol W in FIG. 2) can be cut off from the iron core 42, and the size and weight can be reduced. Further, since the magnetic path area of the electromagnet core 42 becomes constant at any position in the radial direction, the magnetic flux density becomes uniform along the magnetic path, and the efficiency is improved.

In this case, when the outer diameter of the electromagnet iron core 42 is the same as the conventional one, the coil storage volume in the iron core is increased by an amount corresponding to the useless portion W, so that a margin can be provided. And the wire diameter can be increased. Therefore, the copper loss is reduced, the allowable value of the axial thrust that can be supported in a non-contact manner is increased, and the performance is improved.

Conversely, when the coil storage volume is made conventional, the number of turns and the wire diameter are made the same as before, while the iron core 4 for the electromagnet is used.
Since the outer diameter of No. 2 can be reduced, the efficiency can be improved by reducing the iron loss, and the size and weight can be reduced. Furthermore, if the thrust magnetic bearing is reduced in size and weight as described above, the flywheel battery device is also reduced in size and weight, so that it is possible to provide a battery device suitable for in-vehicle use.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the back magnetic path portion 53 of the electromagnet iron core 42 and the inner surfaces 53A and 52aA of the inward magnetic path portion 52a are tapered, but only one of these inner surfaces is a tapered surface. Is also good. 6 and 7, only the inner surface 53A of the back magnetic path 53 is a tapered surface.

In the above-described embodiment, as an embodiment of a configuration in which the thickness of the electromagnet iron core 42 gradually decreases outward in the radial direction, the inner surface 5 of the back magnetic path portion 53 and the inward magnetic path portion 52a is formed.
Although 3A and 52aA are configured as tapered surfaces approaching the outer surfaces 53B and 52aB, even if the thickness does not decrease continuously as in this configuration, for example, the thickness decreases stepwise. Good.

In the above embodiment, the magnetic path portion extending in the radial direction of the electromagnet core 42 is only the back magnetic path section 53 and the inward magnetic path section 52a, but does not extend in the radial direction. However, if there is another inclined portion that intersects with the axis O of the electromagnet iron core 42, the thickness of that portion may be temporarily reduced radially outward. For example, when the inner magnetic path 51 and the outer magnetic path 52 located closer to the collar 31 than the inward magnetic path 52a are inclined, the thickness of these may be reduced temporarily.

In the above embodiment, the outer magnetic path 52A of the electromagnet iron core 42 is provided with the inward magnetic path 52a so that the outer magnetic pole 52A is brought closer to the inner magnetic pole 51A. As shown in FIG. 7, the outer magnetic pole 52A and the inner magnetic pole 51A may be separated from each other without providing the inward magnetic path.

Further, in the above embodiment, the thickness of the electromagnet iron core 42 is set so that the magnetic path area becomes uniform along the magnetic path. However, the thickness is not necessarily required to be equal.

[0030]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the invention, the thickness of the electromagnet iron core can be reduced without reducing the required magnetic path area, so that it is possible to improve the efficiency and reduce the size and weight by reducing iron loss. it can. In particular, if the thickness is set such that the magnetic path area of the electromagnet iron core is constant at any position in the radial direction, the thickness is not wasted, and iron loss is further reduced, further improving efficiency. Small size and light weight can be realized.

(2) According to the second aspect of the present invention, when the outer diameter of the iron core for the electromagnet is made to be the same as the conventional one, there is a margin in the coil storage volume by the reduced thickness, and the number of turns can be increased. Since the wire diameter can be increased, the copper loss can be reduced and the performance can be improved. Conversely, when the coil storage volume is the same as before, the outer diameter of the iron core for the electromagnet can be reduced while keeping the number of turns and the wire diameter as before, thereby improving the efficiency and reducing the size and weight by reducing iron loss. be able to.

(3) According to the third aspect of the present invention, the iron core for the electromagnet is provided with a thrust magnetic bearing having a reduced size and weight or an increased coil storage capacity. A flywheel battery device can be configured, and a battery device suitable for in-vehicle use can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a thrust magnetic bearing according to the present invention and a flywheel battery device including the same.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a plan view of a stator.

FIG. 4 is a sectional view of the stator.

FIG. 5 is an enlarged sectional view of the same stator.

FIG. 6 is a sectional view showing a thrust magnetic bearing according to another embodiment of the present invention.

FIG. 7 is a partial sectional view showing a main part of a thrust magnetic bearing according to still another embodiment of the present invention.

FIG. 8 is a sectional view showing a conventional example of a thrust magnetic bearing.

FIG. 9 is a sectional view showing a main part of the thrust magnetic bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Flywheel 15 Thrust magnetic bearing 21 Rotor part (rotating body) 31 Collar 32 Stator 41 Circular electromagnet coil 42 Electromagnet core 53A Inner surface of backside magnetic path (inner surface of electromagnet core) 52aA Inward magnetic path part Inner surface (inner surface of iron core for electromagnet) 53B Outer surface of back magnetic path (outer surface of iron core for electromagnet) 52aB Outer surface of inward magnetic path portion (outer surface of iron core for electromagnet)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shin Aoki 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Koichi Ono 1-4-1 Chuo, Wako-shi, Saitama F term in Honda R & D Co., Ltd. (reference) 3J102 AA01 BA03 BA18 CA19 CA28 DA02 DA09 DA30 GA09 5H607 AA12 BB01 BB02 CC03 DD19 EE42 GG02 GG17

Claims (3)

[Claims] 1. A collar provided on a rotating body to be supported and protruding radially outward of the rotating body, and a stator for supporting the collar in a non-contact manner against an axial thrust acting on the rotating body. A thrust magnetic bearing in which the stator comprises an annular electromagnet coil and an electromagnet iron core having a shape surrounding the annular electromagnet coil, wherein the thickness of the electromagnet iron core is outside the radial direction. A thrust magnetic bearing, characterized in that the number decreases gradually toward the direction. 2. The magnetic bearing stator according to claim 1, wherein an inner surface of the iron core for the electromagnet gradually approaches an outer surface in a radially outward direction. 3. The thrust according to claim 1, wherein the thrust acting on the flywheel in the flywheel battery device converts the rotational energy stored in the flywheel into electric energy and supplies the energy to the outside. A flywheel battery device supported by a magnetic bearing.