JPH11280764A - Thrust bearing of superconducting flywheel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain deformation by centrifugal force, and uniformly hold clearance between thrust bearings by vertically symmetrically installing permanent magnet assemblies on the upper side and the lower side of a thrust collar so that both centrifugal forces become the same with each other. SOLUTION: When operating a superconducting flywheel, centrifugal force FRu of an upper side permanent magnet assembly 60b and centrifugal force FRd of a lower side permanent magnet assembly 60a become the same with each other since weight, a shape and an installing position of these magnet assemblies 60b, 60a are equal to each other, and laterally uniformly act on the cylindrical part 5a of a thrust collar 5 since the assemblies are vertically symmetrically installed in the disk part 5b. The comparatively thin cylindrical part 5a is vertically uniformly bent in the outer peripheral direction over both ends from the root to the central disk part 5b by these centrigugal forces FRu , FRd , and does not deviate to the upper side like a conventional product. Therefore, clearance between the permanent magnet assembly 60a and a superconducting bulk body is also uniformized over the bearing inner/outer periphery to prevent reduction in bearing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a superconducting thrust bearing in a power storage flywheel.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view of a superconducting flywheel device for electric power storage taken along a rotation axis. In FIG. 3, reference numeral 1 denotes a CFRP flywheel ring, which is fixed to the outer periphery of a disk-shaped support disk 2.
3 'is an upper shaft, 4' is an intermediate shaft and 6 'is a lower shaft. The support disk 2 is sandwiched between a lower flange of the upper shaft 3' and an upper flange of the intermediate shaft 4 ', and a plurality of bolts are provided. (Not shown).

Reference numeral 5 denotes a disk-shaped thrust collar made of a magnetic iron plate. The thrust collar 5 is sandwiched between the lower flange of the intermediate shaft 4 'and the upper flange of the lower shaft 6', and has a plurality of bolts 2.
4. It is fixed by a nut 25 (see FIG. 5).
A ring-shaped inner permanent magnet 7, an intermediate ring 9 made of a non-magnetic material, and a ring-shaped outer permanent magnet 8 are attracted and held by the thrust collar 5 in this order from the inner peripheral side. It is designed to rotate integrally with a rotating shaft composed of a shaft 4 ', a lower shaft 6' and the like. The thrust collar 5,
The inner peripheral permanent magnet 7, the outer peripheral permanent magnet 8, and the intermediate ring constitute a permanent magnet assembly 60 (see FIG. 5).

[0004] Reference numeral 10 denotes a high-temperature superconducting bulk body which is disposed opposite to the inner and outer permanent magnets 7 and 8 with a small gap therebetween, and 11 denotes a liquid nitrogen reservoir for containing liquid nitrogen. Liquid nitrogen is introduced into the liquid nitrogen reservoir 11 from the outside X via a pipe 12 to generate magnetic repulsion between the high-temperature superconducting bulk body 10 and the permanent magnet assembly 60 having the permanent magnets 7 and 8. The thrust collar 5 to which the rotating shaft, the support disk 2 ', the flywheel ring 1, the permanent magnets 7, 8 and the intermediate ring 9 are fixed.
The superconducting thrust bearing 50 which supports and floats the weight of the rotor 60 is constituted. Reference numeral 13 denotes a pipe connecting the liquid nitrogen reservoir 11 and the external Y, and a liquid nitrogen reservoir 1
In FIG. 1, the nitrogen gas evaporated by the heat of intrusion from the outside is discharged to the outside Y.

An upper radial bearing 14 supports the upper shaft 3 ', and a lower radial bearing 15 supports the lower shaft 6'. These radial bearings 14 and 15 are composed of normal-conducting magnetic bearings. You. The shaft end of the upper shaft 3 'and the shaft end of the lower shaft 6' are auxiliary supported by an upper auxiliary bearing 16 and a lower auxiliary bearing 17 made of rolling bearings. Reference numeral 18 denotes a generator and a motor for inputting and outputting rotational energy of the flywheel device by charging and discharging.

Reference numeral 21 denotes a casing in which the central portion of the rotor 60 is accommodated; 20, a casing in which the power generator and the motor 18 are accommodated; 19, a casing in which the upper radial bearing 14 and the upper auxiliary bearing 16 are mounted; This is a casing to which the lower radial bearing 15 and the lower auxiliary bearing 17 are attached.
0, 21 and 22 are fixed in a liquid-tight manner by a plurality of bolts (not shown), so that the inside is kept in a vacuum.

Reference numeral 21 'denotes a protective material wound around the outer periphery of the central casing 21, and 23 denotes a vacuum exhaust port provided in the casing 20, and the exhaust port 23 accommodates the rotor 60. The casing 19, 20, 2
By evacuating the insides 1 and 22 in the Z direction in the drawing, windage loss due to rotation of the rotor 60 and vacuum insulation are performed.

During operation of the flywheel device, as in the operation mode shown in FIG. 4, when the rotational speed increases, power is generated during A → B and charged by the electric motor 18, and constant rotation is performed between B → C. The power is stored by the number, and the discharge is performed between C and D when the rotation speed decreases.

During normal operation of the flywheel device, the thrust load due to the weight of the rotor 60 rotating at a high speed is supported by the superconducting thrust bearing 50 so that the rotor 60 is rotated while floating, and the radial load is reduced. It is supported in a non-contact manner by an upper radial bearing 14 and a lower radial bearing 15 which are normal conducting magnetic bearings.

On the other hand, when the upper and lower radial bearings 14 and 15 composed of the magnetic bearings malfunction, the upper and lower radial bearings 14 and 15 are used to prevent damage to the rotor 60 and bearings.
The rotor 60 is supported by the upper and lower auxiliary bearings 16 and 17 having a bearing clearance of about の of the bearing clearance of the lower radial bearings 14 and 15. The intermediate ring 9 supports the centrifugal force of the inner permanent magnet 7 that rotates together with the thrust collar 5. The intermediate ring 9 is supported by the outer peripheral permanent magnet 8 in the radial direction.

[0011]

FIG. 5 to FIG.
Permanent magnets during operation of conventional superconducting flywheel devices
The situation of the centrifugal force acting on the stone assembly 60 is shown.
5 to 6, F _R1, F_R2, F_R3... F_RNIs above
This is the centrifugal force generated by the permanent magnet assembly 60. From the same figure
As is apparent, in the conventional device shown in FIG.
Inner circumference permanent magnet 7 and intermediate ring constituting stone assembly 60
9, division in which the outer peripheral permanent magnet 8 is divided in the radial direction
Because of the mold, each element is hoop stress
Cannot support itself, and the centrifugal force F_RNIs
It acts on the inner peripheral surface 5a of the thrust collar 5.

Due to the centrifugal force F _RN , the outer peripheral portion of the thrust collar 5 is deformed to warp upward as shown in FIG. In the conventional case, the deformation of the angle θ increases the outer circumferential gap between the high-temperature superconducting bulk body 10 and the permanent magnet assembly 60, thereby increasing the floating performance of the superconducting thrust bearing 50, that is, the bearing performance. There is a problem that it decreases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a superconducting flywheel device in which a superconducting thrust bearing is prevented from being deformed by centrifugal force from a permanent magnet assembly, and a gap between a permanent magnet assembly and a high-temperature superconducting bulk body is made uniform. The purpose is to improve the floating performance of the thrust bearing, that is, the bearing performance.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first means of the invention is to provide a rotating shaft and a rotating shaft which are driven to rotate in a casing held in a vacuum. A rotor including an annular flywheel ring fixed via a support disk, a permanent magnet assembly attached to a thrust collar made of a magnetic material fixed to the rotating shaft, and a small gap between the permanent magnet assembly and the permanent magnet assembly. In a superconducting flywheel device comprising a superconducting thrust bearing consisting of a superconducting bulk body installed as described above, the superconducting thrust bearing is configured such that the permanent magnet assembly is vertically symmetrical above and below the thrust collar. And a thrust bearing for a superconducting flywheel device, wherein one set of each is mounted so that both centrifugal forces are the same.

According to the above means, the upper and lower two permanent magnet assemblies are vertically and symmetrically mounted on the upper and lower sides of the thrust collar so that both centrifugal forces are the same. The amount of deformation of the thrust collar due to the centrifugal force of the assembly is uniform on the upper and lower sides without being deformed to the upper side unlike the conventional one, and therefore, the gap between the permanent magnet assembly and the superconducting bulk body is also the inner circumference. This is uniform on the outer side and the outer peripheral side, thereby preventing a decrease in the floating performance of the superconducting thrust bearing.

A second means is the superconducting flywheel device, wherein the thrust collar and the permanent magnet assembly are formed of a cross-wound CFRP (plastic plate) having a plurality of carbon fibers disposed axially outside the assembly. A peripheral ring is provided, and an outer peripheral ring made of filament-wound CFRP in which a plurality of carbon fibers are arranged in a circumferential direction is fixed outside the inner peripheral ring.

According to the second means, since the CFRP of the filament winding constituting the outer peripheral ring has a high strength against hoop stress (hoop stress), the radius due to the centrifugal force of the permanent magnet assembly is increased. Since the deformation in the direction is minimized and the cross-wound CFRP forming the inner peripheral ring has high bending rigidity, sufficiently large rigidity can be obtained against the bending component due to the centrifugal force.

Therefore, the deformation of the thrust bearing is greatly reduced as compared with the conventional one by combining the outer ring having high strength against the hoop stress and the inner ring having high bending rigidity. The gap between the permanent magnet assembly and the superconducting bulk body is properly maintained.

Further, the third means comprises the first means and the second means.
The effect of the first and second means is superimposed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. The present invention relates to an improvement of the superconducting thrust bearing 50 of the superconducting flywheel device shown in FIG.

FIG. 1 is a sectional view of a main part of a superconducting thrust bearing portion according to the embodiment, taken along a rotation axis. In FIG. 1, reference numeral 4 'denotes an intermediate shaft, 6' denotes a lower shaft, and the intermediate shaft. A thrust collar 5 is sandwiched between the lower surface of the flange 4 'and the upper surface of the flange of the lower shaft 6', and is fastened and fixed by a plurality of bolts 24 and nuts 25 arranged at equal intervals in the circumferential direction.

The thrust collar 5 has a disk portion 5 on its inner periphery.
b, a cylindrical portion 5a is formed on the outer periphery. The cylindrical part 5
Since the flywheel device rotates at high speed, a is formed to be relatively thin in order to suppress the effect of a large centrifugal force.

Reference numeral 26a denotes an inner peripheral ring in which carbon fibers are arranged in the axial direction, and a cross-wound CF in which resin is packed between the rings is provided.
The inner peripheral surface is fixed to the outer peripheral surface of the cylindrical portion 5a of the thrust collar. 26a ₁ shows an axial carbon fiber of the same cross-wound CFRP. Reference numeral 26b denotes an outer peripheral ring, which is a filament winding CFRP in which carbon fibers are wound in a circumferential direction and a resin is interposed therebetween.
The inner peripheral surface is fixed to the outer peripheral surface of the inner peripheral ring 26a. 26b ₁ shows a circumferential winding of carbon fibers of the same filament winding CFRP.

Two sets of permanent magnet assemblies 60b, 60a are fixed on the upper and lower surfaces of the disk portion 5b of the thrust collar 5 symmetrically in size and position. That is, the lower permanent magnet assembly 60a includes an inner peripheral permanent magnet 7, an intermediate ring 9 made of a non-magnetic material, and an outer peripheral permanent magnet 8 shown in FIG. It is provided with such a pole arrangement. The upper permanent magnet assembly 60b includes an inner peripheral permanent magnet 7 ', an intermediate ring 9' made of a non-magnetic material, and an outer peripheral permanent magnet 8 'in this order from the inner peripheral side.
Are arranged so that the respective members are symmetrical to the respective members of the upper permanent magnet assembly 60b with the arrangement of the poles as shown in FIG.

During operation of the superconducting flywheel constructed as described above, as shown in FIG. 2, the centrifugal force F _Ru of the upper permanent magnet assembly 60b and the centrifugal force F _Ru of the lower permanent magnet assembly 60a, as shown in FIG. _Rd has the same value because the upper and lower permanent magnet assemblies 60b and 60a have the same specifications, that is, their weight, shape and mounting position are the same, and the upper and lower permanent magnet assemblies 60b and 60a have the same value. And 60a are vertically symmetrically attached to the disk portion 5b, so that they act equally on the cylindrical portion 5a of the thrust collar 5. As a result of the centrifugal forces F _Ru and F _Rd , the relatively thin cylindrical portion 5 a is vertically and uniformly bent in the outer circumferential direction from the base to the center disk portion 5 b to both ends as shown by the broken line in FIG. It is not deformed to the upper side like the one of the above.

The centrifugal forces F _Ru and F _Rd acting on the flywheel ring 26 include upper and lower uniform centrifugal forces F _Ru1 and F _{Rd 1} including a bending component _directed from both sides to the center. Become.

[0027] However, filament winding CFRP having a circumferential winding of carbon fibers 26b ₁ constituting the outer peripheral ring 26b has a high strength with respect to the hoop stress, the thrust collar by the centrifugal force F _Ru1 and F _Rd1 5 The radial deformation of the cylindrical portion 5a is kept to a minimum. However, the CFRP having the circumferentially wound carbon fibers 26b ₁ is not
_Ru1 and F _Rd1 have low strength against bending components.

[0028] Therefore, in this embodiment, C having an axial carbon fiber 26a ₁ flexural rigidity is large between the outer ring 26b consisting of a cylindrical portion 5a and the filament winding CFRP of the thrust collar 5
Since the inner peripheral ring 26a made of FRP is provided, the inner peripheral ring 26a has sufficiently high rigidity against the bending component. Therefore,
The deformation of the thrust collar 5 is kept to a minimum, the expansion of the gap between the permanent magnet assembly 60a and the high-temperature superconducting bulk body 10 is prevented, the gap is properly maintained, and the superconducting thrust bearing 50 has the required floating characteristics. Can be maintained.

[0029]

The present invention is configured as described above.
According to the first aspect of the present invention, two sets of upper and lower permanent magnet assemblies constituting the thrust bearing are mounted on the upper and lower sides of the thrust collar in a vertically symmetric manner so that both centrifugal forces are the same. As a result, the deformation of the thrust collar is not biased upward as in the prior art, but is uniform on the upper and lower sides.

Therefore, the clearance between the permanent magnet assembly and the superconducting bulk body is also uniform over the inner and outer circumferences of the bearing, and the floating performance of the superconducting thrust bearing due to the centrifugal force of the permanent magnet assembly, that is, the deterioration of the bearing performance. Can be prevented.

According to the second aspect of the present invention, the deformation of hoop stress (tension stress) due to the outer ring made of CFRP of filament winding in which a plurality of carbon fibers are arranged in the circumferential direction is suppressed, and the plurality of carbon fibers are reduced. The deformation of the thrust bearing is reduced by increasing the bending stiffness of the inner ring made of cross-wound CFRP arranged in the axial direction, and the bearing performance is improved by making the bearing gap uniform.

Further, according to the third aspect of the present invention, the above effects of the first and second aspects of the present invention are obtained by being superimposed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a thrust bearing of a superconducting flywheel device according to an embodiment of the present invention.

FIG. 2 is a diagram corresponding to FIG. 1 for explaining an operation in the embodiment.

FIG. 3 is a longitudinal sectional view of a superconducting flywheel device using a conventional thrust bearing.

FIG. 4 is a diagram illustrating the operation of the superconducting flywheel device.

FIG. 5 is a vertical sectional view showing the operation of a conventional superconducting flywheel device.

FIG. 6 is a main part plan view corresponding to FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flywheel ring 4 'Intermediate shaft 5 Thrust collar 5a Disk portion 5b Cylindrical portion 6' Lower shaft 7, 7 'Inner peripheral permanent magnet 8, 8' Outer peripheral permanent magnet 9, 9 'Intermediate ring 10 High-temperature superconducting bulk body 20 Casing 26a inner ring 26b outer ring 50 superconducting thrust bearing 60a, 60b permanent magnet assembly

Continued on the front page (72) Inventor Hiroshi Kawashima 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Prefecture Inside the Mitsubishi Heavy Industries, Ltd. Takasago Machinery Works

Claims (3)

[Claims] A rotor including a rotary shaft driven to rotate in a casing held in vacuum and an annular flywheel ring fixed to the rotary shaft via a support disk;
A permanent magnet assembly attached to a thrust collar made of a magnetic material fixed to the rotation shaft and a superconducting thrust bearing composed of a superconducting bulk body installed with a small gap in the permanent magnet assembly are housed. In the superconducting flywheel device, the superconducting thrust bearing comprises a set of the permanent magnet assembly mounted on the upper and lower sides of the thrust collar so as to be vertically symmetrical and have substantially the same centrifugal force. A thrust bearing for a superconducting flywheel device, characterized in that: 2. A rotor including a rotating shaft driven to rotate and an annular flywheel ring fixed to the rotating shaft via a support disk in a casing held in a vacuum;
A permanent magnet assembly attached to a thrust collar made of a magnetic material fixed to the rotation shaft and a superconducting thrust bearing composed of a superconducting bulk body installed with a small gap in the permanent magnet assembly are housed. In the superconducting flywheel device, the superconducting thrust bearing has an inner peripheral ring made of a cross-wound CFRP (plastic plate) in which a plurality of carbon fibers are arranged in the axial direction outside the thrust collar and the permanent magnet assembly. A thrust bearing for a superconducting flywheel device, in which an outer ring made of filament-wound CFRP in which a plurality of carbon fibers are circumferentially arranged outside the inner ring is fixed. 3. An inner peripheral ring made of a cross-wound CFRP (plastic plate) in which a plurality of carbon fibers are arranged in the axial direction is provided outside the thrust collar and the two upper and lower permanent magnet assemblies. 2. A thrust bearing for a superconducting flywheel device according to claim 1, wherein an outer ring made of filament-wound CFRP in which a plurality of carbon fibers are arranged in a circumferential direction is fixed outside the outer ring.