JPH11190271A - Energy storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the durability of an energy storage device without decreasing the efficiency of energy conversion. SOLUTION: In this energy storage device, upper and lower flywheels 9, 10 supported in such a way as to be rotatable about a common rotation axis K-K are stored in a housing 2. The upper and lower flywheels 9, 10 are rotated in opposite directions to store energy. Dynamic pressure type gas bearing mechanisms 16, 18 are formed between the upper flywheel 9 and the interior wall surface 2b of the housing, and a dynamic pressure type gas bearing mechanism 20 is formed between the lower flywheel 10 and the interior wall surface 2b of the housing, so that the upper and lower flywheels 9, 10 are supported by the housing 2. The upper and lower flywheels 9, 10 are placed adjacent to each other, and additional dynamic pressure type gas bearing mechanisms 22, 24 are formed between the upper and lower flywheels 9, 10, so that the flywheels 9, 10 are supported against each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an energy storage device.

[0002]

2. Description of the Related Art Conventionally, a pair of inertial masses rotatably supported around a common rotation axis are housed in a housing, and these inertial masses are rotated in opposite directions to store energy. A known energy storage device is known. That is, for example, when an electric current is applied to the electromagnetic coil of the energy storage device to form a magnetic field, the inertial mass is rotated by the interaction between the magnetic field and the magnetic field of the permanent magnet attached to the inertial mass. Are stored in the form of kinetic energy.

In order to increase the storage capacity of such an energy storage device, it is necessary to rotate the inertial mass at a high speed. However, when the inertial mass body is rotated at a high speed, a large stress acts on the bearing of the inertial mass body, and as a result, it becomes difficult to secure the durability of the energy storage device. Therefore, there is known an energy storage device in which a magnetic bearing mechanism is formed between each inertial mass body and the inner wall surface of the housing so that these inertial mass bodies are supported by the housing.
506754). In this energy storage device, the inertial mass is supported in a non-contact manner by forming a magnetic bearing mechanism between each inertial mass and the inner wall surface of the housing, thereby preventing a large stress from acting on the bearing of the inertial mass. Like that.

[0004]

However, in order to reliably maintain the inertial mass in a proper position in this energy storage device, the magnetic field formed by the magnetic bearing mechanism must be increased. However, as described above, in the energy storage device, the energy is stored by the interaction between the magnetic fields of the electromagnetic coil and the permanent magnet. Therefore, if the magnetic field formed by the magnetic bearing mechanism is large, the magnetic field formed by the electromagnetic coil or the permanent magnet Is disturbed, and as a result, there is a problem that the conversion efficiency from electric energy to kinetic energy is reduced.

[0005]

According to a first aspect of the present invention, a pair of inertial mass bodies rotatably supported around a common rotation axis are accommodated in a housing, and these inertial mass bodies are accommodated in the housing. In an energy storage device configured to store energy by rotating masses in opposite directions,
A dynamic pressure type gas bearing mechanism is formed between each inertial mass body and the inner wall surface of the housing, and these inertial mass bodies are supported by the housing. That is, in the first aspect, the inertial mass body is supported in a non-contact manner without lowering the energy conversion efficiency.

According to a second aspect, in the first aspect, the dynamic pressure type gas bearing mechanism is formed between an outer peripheral surface of each inertial mass body and the inner wall surface of the housing. That is, in the second invention, the dynamic pressure type gas bearing mechanism is formed between the outer peripheral surface of the inertial mass body that rotates at the largest linear velocity among the inertial mass bodies and the inner wall surface of the housing, so that a large supporting force is formed.

According to a third aspect, in the second aspect, the outer peripheral surface of each inertial mass body is inclined with respect to the rotation axis. That is, in the third aspect, the support force in the radial direction and the support force in the rotation axis direction are simultaneously formed. According to a fourth aspect, in the first aspect, the pair of inertial mass bodies are arranged adjacent to each other, and an additional hydrodynamic gas bearing mechanism is formed between the inertial mass bodies to connect the inertial mass bodies to each other. It is supported by another inertial mass. That is, in the fourth invention, each inertial mass is not supported separately but supported by the housing and another inertial mass.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, 1 is an energy storage device, 2 is a housing defining an annular internal space 2a, 3 is a base made of, for example, a vehicle body, 4 is a housing 2 fixed to the base 3. Fixture 5 is housing 2
And a vibration absorbing member 6 made of, for example, an air mat interposed between the base 3 and the fixture 4. The vibration absorbing member 6 is fixed in the internal space 2 a of the housing 2 and
Are shown, respectively. The housing 2 and the annular member 6 are formed symmetrically with respect to an axis KK extending vertically and a symmetry plane JJ extending horizontally.

As shown in FIG. 1, an upper annular electromagnetic coil 7 and a lower annular electromagnetic coil 8 are housed in the housing inner space 2a so as to be vertically separated from each other. These upper and lower annular electromagnetic coils 7, 8 are fixed to the housing inner wall surface 2b, respectively. Upper annular electromagnetic coil 7
An upper flywheel 9 is disposed in the housing internal space 2a between the lower annular electromagnetic coil 8 and the annular member 6, and a lower flywheel 10 is disposed in the housing internal space 2a between the lower annular electromagnetic coil 8 and the annular member 6. Therefore, in this embodiment, a pair of flywheels are vertically aligned adjacent to each other. As will be described later, the upper and lower flywheels 9 and 10 are rotatably supported around the axis KK and in opposite directions. Further, on each inner peripheral surface of the upper and lower flywheels 9 and 10,
The corresponding upper and lower annular electromagnetic coils 7, 8 respectively
The annular permanent magnets 11 and 12 are attached to face.

The interior space 2a of the housing, the upper and lower annular electromagnetic coils 7, 8, the upper and lower flywheels 9, 10, and the permanent magnets 11, 12 are aligned with the axis K-.
It is arranged concentrically around K. The gap formed between the upper and lower flywheels 9 and 10 is located in the symmetry plane JJ, and the upper annular electromagnetic coil 7 and the lower annular electromagnetic coil 8 and the permanent magnet 11 and the permanent magnet 12 are symmetrical, respectively. It is arranged symmetrically with respect to the plane JJ.

The outer peripheral surface 9a of the upper flywheel 9 is inclined with respect to the axis KK so as to expand toward the lower flywheel 10, and the outer peripheral surface 10a of the lower flywheel 10 faces the upper flywheel 9. It is inclined with respect to the axis KK so as to expand. On the other hand, the inner wall surface 2b of the housing defined by the annular member 6 is formed on the outer peripheral surface 9 of the upper and lower flywheels 9, 10.
a, 10a, the housing inner wall surface 2b facing the outer peripheral surface 9a of the upper flywheel 9 is expanded downward, and the housing inner wall surface facing the outer peripheral surface 10a of the lower flywheel 10 is formed. 2b expands upward.

At the center of the bottom surface 9b of the upper flywheel 9, a concave portion 13 expanding toward the lower flywheel 10 is provided.
Is formed at the center of the top surface 10c of the lower flywheel 10, and a convex portion 14 formed complementary to the concave portion 13 and received in the concave portion 13 is formed. 1 and 2
As shown in (A), a plurality of spirally extending grooves 15 are formed on the outer peripheral surface 9a of the upper flywheel 9. These grooves 15 extend clockwise from the center of the upper flywheel 9 toward the peripheral edge when viewed from above, and are therefore rotated in the direction of rotation of the upper flywheel 9 (FIG. 2).
It extends in the opposite direction to the arrow R1) in (A). A slight gap is formed between the outer peripheral surface 9a of the upper flywheel 9 and the flat housing inner wall surface 2b facing the outer peripheral surface 9a, thus facing the outer peripheral surface 9a of the upper flywheel 9 and the same. A dynamic pressure type gas bearing mechanism 16 is formed between the housing and the inner wall surface 2b.

Similarly, the top surface 9c of the upper flywheel 9
A plurality of spirally extending grooves 17 are also formed on the upper side. These grooves 17 extend in the same direction as the grooves 15 when viewed from above. A slight gap is also formed between the top surface 9c of the upper flywheel 9 and the flat housing inner wall surface 2b facing the same, so that the outer peripheral surface 9a of the upper flywheel 9 faces the same. Housing inner wall surface 2b
A dynamic pressure type gas bearing mechanism 18 is also formed between them.

As shown in FIGS. 1 and 2B, a plurality of spirally extending grooves 19 are also formed on the outer peripheral surface 10a of the lower flywheel 10. These grooves 19
Extends counterclockwise from the center of the lower flywheel 10 toward the peripheral edge when viewed from above, and is therefore opposite to the direction of rotation of the lower flywheel 10 (arrow R2 in FIG. 2B). Extends to. A slight gap is formed between the outer peripheral surface 10a of the lower flywheel 10 and the flat housing inner wall surface 2b facing the outer peripheral surface 10a.
The dynamic pressure type gas bearing mechanism 20 is formed between a and the inner wall surface 2b of the housing facing this.

That is, in this embodiment, the flywheels 9 and 10 are supported by the housing 2 via the dynamic pressure type gas bearing mechanisms 16, 18 and 20. Further, FIG.
As shown in (A), the bottom surface 9 of the upper flywheel 9
A plurality of grooves 21 extending spirally are also formed on b. These grooves 21 extend in the same direction as the grooves 15, 17 when viewed from above. The bottom surface 9b of the upper flywheel 9 and the flat top surface 10c of the lower flywheel 10 facing the bottom surface 9b.
Between the bottom surface 9b of the upper flywheel 9 and the top surface 10c of the lower flywheel 10 facing the same. Is formed.

Further, as shown in FIG. 2B, a plurality of spirally extending grooves 23 are formed on the peripheral surface of the convex portion 14 of the lower flywheel 10. These grooves 23 extend in the same direction as the grooves 19 when viewed from above. A slight gap is also formed between the peripheral surface of the convex portion 14 and the flat peripheral surface of the concave portion 13 facing the convex portion 14.
An additional hydrodynamic gas bearing mechanism 24 is formed between 4 and recess 13 facing it.

That is, in this embodiment, the upper flywheel 9 is supported by the lower flywheel 10 via the additional dynamic pressure type gas bearing mechanisms 22 and 24, and the lower flywheel 10 is supported via the dynamic pressure type gas bearing mechanisms 22 and 24. Supported by the upper flywheel 9. Further, an annular permanent magnet 25 is disposed on the bottom surface 10 b of the lower flywheel 10, and the inner wall surface 2 of the housing facing the permanent magnet 25 is disposed.
An annular permanent magnet 26 is arranged on b. These permanent magnets 25 and 26 have the same magnetic poles, so that a magnetic bearing mechanism 27 is formed between the bottom surface 10b of the lower flywheel 10 and the inner wall surface 2b of the housing.

Similarly, the bottom surface 9b of the upper flywheel 9
An annular permanent magnet 28 is disposed on the upper side, and the permanent magnet 2
An annular permanent magnet 29 is arranged on the top surface 10 c of the lower flywheel 10 facing the upper surface 8. These permanent magnets 2
8, 29 also have the same magnetic poles as one another, so that an additional magnetic bearing mechanism 30 is formed between the bottom surface 9b of the upper flywheel 9 and the top surface 10c of the lower flywheel 10.

The upper flywheel 9 and the permanent magnets 11 and 28 integral therewith, and the lower flywheel 10 and the permanent magnets 12, 25 and 29 integral therewith form inertial masses, respectively. Are equal to each other. Next, the operation of the energy storage device 1 of FIG. 1 will be described. When electric energy is supplied to the upper and lower annular electromagnetic coils 7, 8 from an electric energy source (not shown), the magnetic field formed by the upper and lower annular electromagnetic coils 7, 8 and the upper and lower flywheels 9, 10 respectively. Permanent magnets 11 and 12 attached
The upper and lower flywheels 9, 10 are caused to rotate about the axis of rotation KK by interaction with the magnetic field.
The upper and lower flywheels 9 and 10 continue to rotate even after the supply of energy to the upper and lower annular electromagnetic coils 7 and 8 from the electric energy source is stopped, so that the electric energy is stored in the form of kinetic energy. Stored in device 1.

In this case, the electric energy supplied to the upper and lower annular electromagnetic coils 7, 8 is made equal to each other,
Therefore, the upper and lower flywheels 9 and 10 rotate at the same speed with respect to each other. In addition, since the rotation directions of the upper and lower flywheels 9 and 10 are opposite to each other as described above, the gyro moment acting on these upper and lower flywheels 9 and 10 can be offset. As a result, for example, the rotational axis K
Even if −K deviates from the normal position, stable rotational movement of the upper and lower flywheels 9 and 10 can be ensured.

When the upper and lower flywheels 9 and 10 are rotating as described above, the upper and lower flywheels 9 and 10 are driven by the hydrodynamic gas bearing mechanisms 16 and 1.
8, 20 and additional hydrodynamic gas bearing mechanisms 22, 24. That is, the dynamic pressure type gas bearing mechanism 16
3, a repulsive force, that is, a supporting force F1 acts on the outer peripheral surface 9a of the upper flywheel 9 due to the dynamic pressure generated when the upper flywheel 9 rotates, that is, when the upper flywheel 9 is turned downward in the rotation axis KK direction. Force and radial inward force act. Further, in the dynamic pressure type gas bearing mechanism 18, a repulsive force F2 acts on the top surface 9c of the upper flywheel 9, and
That is, a downward force acts on the rotation axis KK. Further, in the additional hydrodynamic gas bearing mechanism 22, a repulsive force F3 acts on the bottom surface 9b of the upper flywheel 9, that is, an upward force in the direction of the rotational axis KK acts. Further, in the dynamic pressure type gas bearing mechanism 24, the concave portion 1 of the upper flywheel 9 is formed.
3, a repulsive force F4 acts, that is, an upward force in the rotation axis KK and an outward force in the radial direction. In this way, the upper flywheel 9 is supported by the housing 2 and the lower flywheel 10.

Similarly, in the hydrodynamic gas bearing mechanism 20, a repulsive force F5 acts on the outer peripheral surface 10a of the lower flywheel 10, that is, an upward force in the direction of the rotational axis KK and an inward force in the radial direction act. . Further, in the additional dynamic pressure type gas bearing mechanism 22, a repulsive force F3 acts on the top surface 10c of the lower flywheel 10, that is, a downward force acts on the rotation axis KK. Further, in the hydrodynamic gas bearing mechanism 24, a repulsive force F4 acts on the convex portion 14 of the lower flywheel 10, that is, a downward force in the direction of the rotation axis KK and an inward force in the radial direction act. Thus, the lower flywheel 10 is supported by the housing 2 and the upper flywheel 9.

In the dynamic pressure type gas bearing mechanisms 16 and 18, a slight gap is formed between the upper flywheel 9 and the housing inner wall surface 2a.
0, the lower flywheel 10 and the inner wall surface 2a of the housing
And a slight gap is formed between the upper flywheel 9 and the lower flywheel 10 in the additional hydrodynamic gas bearing mechanisms 22 and 24. Therefore, the upper and lower flywheels 9 and 10 are supported without contact,
Thus, the durability of the energy storage device 1 can be improved.

In such a dynamic pressure type gas bearing mechanism, the supporting force increases as the rotational speed of the flywheel increases. Therefore, in this embodiment, even when the upper and lower flywheels 9 and 10 rotate at a high rotation speed, the upper and lower flywheels 9 and 10 can be reliably supported. Incidentally, it is not always necessary to incline the outer peripheral surfaces 9a, 10a of the upper and lower flywheels 9, 10 with respect to the rotation axis KK. However, the outer peripheral surfaces 9a, 10a of the upper and lower flywheels 9, 10 are inclined with respect to the rotation axis KK, and a dynamic pressure type gas bearing mechanism is provided between each outer peripheral surface and the housing inner wall surface 2a facing the outer peripheral surface. If it forms, the force of the upper and lower flywheels 9 and 10 in the direction of the rotational axis KK and the force in the radial direction can act simultaneously. Therefore, even if the dynamic pressure type gas bearing mechanism is formed only between each outer peripheral surface and the housing inner wall surface 2a facing the outer peripheral surface, good stability of the upper and lower flywheels 9 and 10 can be ensured.

On the other hand, the upper and lower flywheels 9,
When the 10 rotates, the upper and lower flywheels 9 and 10 expand due to the centrifugal force acting on the upper and lower flywheels 9 and 10. As a result, the distance between each outer peripheral surface 9a, 10a of the upper and lower flywheels 9, 10 and the corresponding housing inner wall surface 2b is reduced, and each outer peripheral surface 9a, 10a and the housing inner wall surface 2b may collide with each other. There is. However, in this embodiment, when the upper and lower flywheels 9 and 10 rotate, a downward force acts on the outer peripheral surface 9a in the direction of the rotational axis KK, and a downward force acts on the outer peripheral surface 10a. Therefore, the upper flywheel 9 moves downward in the direction of the rotation axis KK while expanding, and the lower flywheel 10 moves upward in the direction of the rotation axis KK while expanding. As a result, it is possible to prevent the outer peripheral surfaces 9a, 10a and the corresponding housing inner wall surface 2b from colliding with each other.

That is, taking the upper flywheel 9 as an example, when stopped or when the rotation speed is low, the upper flywheel 9 is at the position shown by the solid line in FIG. It will be the position shown by the broken line. That is, when the upper flywheel 9 is rotating or at a high rotation speed, the upper flywheel 9 is radially outward and at the rotation axis K-
It will be located on the lower side in the K direction. Note that the same applies to the lower flywheel 10, and a description thereof will be omitted.

The concave portion 13 of the upper flywheel 9 and the convex portion 14 of the lower flywheel 10 are for maintaining the relative positions of the upper and lower flywheels 9 and 10 at regular positions. That is, when the concave portion 13 and the convex portion 14 are not provided, the relative positions of the upper and lower flywheels 9 and 10 are determined via the annular member 6. However, if the relative positions of the upper and lower flywheels 9 and 10 are determined indirectly in this way, it becomes difficult to maintain the relative positions of the upper and lower flywheels 9 and 10 at regular positions. The rotation axes of the lower flywheels 9 and 10 cannot be maintained in common. As a result, the gyro moment acting on the upper and lower flywheels 9 and 10 cannot be reliably canceled.

On the other hand, when the concave portions 13 and the convex portions 14 are provided to directly determine the relative positions of the upper and lower flywheels 9 and 10 as in the present embodiment, the relative positions of the upper and lower flywheels 9 and 10 are changed. The position can be reliably maintained in the correct position, and thus the rotation axes of the upper and lower flywheels 9 and 10 can be reliably maintained in common. Therefore, the gyro moment can be surely canceled, so that the durability of the energy storage device 1 can be further improved.

As described above, in this embodiment, the upper flywheel 9 is supported by the housing 2 and the lower flywheel 10, and the lower flywheel 10 is supported by the housing 2 and the upper flywheel 9. However, the plate material constituting the housing inner wall surface 2b is inserted between the upper and lower flywheels 9, 10 so that the upper and lower flywheels 9, 1 are inserted.
0 may be supported only by the housing 2. However, this makes the configuration and assembly of the energy storage device 1 complicated. Since the upper and lower flywheels 9 and 10 rotate in opposite directions to each other, the upper and lower flywheels 9 and 10 rotate.
Relative speed increases. Thus, in this embodiment, the upper and lower flywheels 9, 10 are arranged adjacent to each other to form additional hydrodynamic gas bearing mechanisms 22, 24 between the upper and lower flywheels 9, 10, whereby the energy storage device 1 And a large repulsive force, that is, a supporting force between the upper and lower flywheels 9 and 10 is obtained.

On the other hand, when the energy stored in the energy storage device 1 is to be output, the upper and lower annular electromagnetic coils 7, 8 are electrically connected to a load such as an electric motor. As a result, the kinetic energy of the upper and lower flywheels 9 and 10 is converted into electric energy and output. In this case, as the amount of energy output from the energy storage device 1 increases, the rotational speeds of the upper and lower flywheels 9, 10 decrease, and when all the energy is output, the upper and lower flywheels 9, 10
Rotation stops. In this case, the dynamic pressure type gas bearing mechanism 1
6, 18, 20 and additional hydrodynamic gas bearing mechanisms 22,
The supporting force at 24 gradually decreases with the rotational speed of the upper and lower flywheels 9, 10, and when the rotational speed of the upper and lower flywheels 9, 10 is reduced to some extent, the upper and lower flywheels 9, 1 are no longer used.
0 cannot be supported.

Therefore, in this embodiment, the dynamic pressure type gas bearing mechanism 16, 18, 20, and the additional dynamic pressure type gas bearing mechanism 2
To ensure that the upper and lower flywheels 9, 10 can be supported even when the support force at 2, 2 is small,
A magnetic bearing mechanism 27 is formed between the bottom surface 10b of the lower flywheel 10 and the housing 2, and a magnetic bearing mechanism 30 is formed between the upper and lower flywheels 9, 10.

In other words, these magnetic bearing mechanisms 27,
Numeral 30 is for supporting the upper and lower flywheels 9, 10 when the upper and lower flywheels 9, 10 are relatively stable. Therefore, the magnetic field formed by these magnetic bearing mechanisms 27 and 30 may be small. Therefore, the magnetic field formed by the upper and lower annular electromagnetic coils 7, 8 or the permanent magnets 11, 12 is prevented from being disturbed, and thus the conversion efficiency from electric energy to kinetic energy is prevented from being reduced. ing.

In order to increase the amount of energy that can be stored in the energy storage device 1, it is necessary to increase the rotation speed of the upper and lower flywheels 9 and 10, but for that purpose, the pressure in the housing internal space 2a is reduced. You only need to lower it. However, if the pressure in the housing internal space 2a is reduced, a sufficient supporting force cannot be obtained in the dynamic pressure type gas bearing mechanism. Therefore, in the present embodiment, the pressure in the housing internal space 2a is determined so as to satisfy these mutually demanding requirements as much as possible, and is maintained at this pressure.

FIG. 5 shows another embodiment. In FIG. 5, the same components as those in the embodiment of FIG. 1 are indicated by the same reference numerals. Referring to FIG. 5, also in this embodiment, a hydrodynamic gas bearing mechanism 16 is formed between the outer peripheral surface 9a of the upper flywheel 9 and the housing inner wall surface 2b facing the upper surface, and the outer peripheral surface 10a of the lower flywheel 10 A hydrodynamic gas bearing mechanism 20 is formed between the housing and the inner wall surface 2b of the housing, and an additional hydrodynamic gas bearing mechanism 22 is provided between the bottom surface 9b of the upper flywheel 9 and the top surface 10c of the lower flywheel 10. Is formed. In the present embodiment, on the outer peripheral surface 9a of the upper flywheel 9, FIG.
A plurality of groove groups 51 extending spirally as shown in FIG.
Is formed. These groove groups 51 extend clockwise from the center of the upper flywheel 9 toward the peripheral edge when viewed from above, and therefore extend in the direction of rotation of the upper flywheel 9 (arrow R1 in FIG. 6A). It extends in the opposite direction. Each groove group 51 includes a plurality of V-shaped grooves 52 aligned along the central axis of each groove group 51.

Similarly, a plurality of spirally extending groove groups 53 are formed on the outer peripheral surface 10a of the lower flywheel 10, as shown in FIG. 6B. These groove groups 53 extend counterclockwise from the center of the lower flywheel 10 toward the peripheral edge when viewed from above, and therefore, rotate in the direction of rotation of the lower flywheel 10 (arrow R in FIG. 6B).
It extends in the opposite direction to 2). Each groove group 53 is a groove group 5
A plurality of V-shaped grooves 54 aligned along the central axis of
Is provided. Furthermore, the bottom surface 9b of the upper flywheel 9
On the upper side, a plurality of groove groups 55 extending spirally are formed as shown in FIG. These groove groups 55 extend in the same direction as the groove groups 51 when viewed from above. Each groove group 55
Has a plurality of V-shaped grooves 56 aligned along the central axis of each groove group 55.

Referring again to FIG. 5, the outer peripheral surface 9a of the upper flywheel 9 and the inner wall surface 2 of the housing facing the outer peripheral surface 9a.
b, a magnetic bearing mechanism 57 is formed. That is, a magnetic force is previously applied to the outer peripheral surface 9a of the upper flywheel 9 made of a magnetic material such as iron, stainless steel, or ferrite, and the magnetic force of the outer peripheral surface 9a is also applied to the inner wall surface 2b of the housing facing thereto. The magnetic force of the magnetic pole is given in advance. As a result, a magnetic repulsive force, that is, a supporting force is formed between the outer peripheral surface 9a and the housing inner wall surface 2b.

Similarly, a magnetic bearing mechanism 58 is also formed between the outer peripheral surface 10a of the lower flywheel 10 and the housing inner wall surface 2a facing the outer peripheral surface 10a. That is, a magnetic force is also applied to the outer peripheral surface 10a of the lower flywheel 10 made of a magnetic material in advance, and the magnetic force of the same magnetic pole as the magnetic force of the outer peripheral surface 10a is also applied to the inner wall surface 2b of the housing facing the lower surface. Comb outer peripheral surface 10a and housing inner wall surface 2
A supporting force is formed between b. Furthermore, the bottom surface 9b of the upper flywheel 9 and the top surface 10c of the lower flywheel 10
A magnetic bearing mechanism 59 is also formed between them. That is,
A magnetic force of the same magnetic pole is applied to the bottom surface 9b of the upper flywheel 9 and the top surface 10c of the lower flywheel 10 in advance, so that a supporting force is formed between the upper and lower flywheels 9, 10. .

As described above, in this embodiment, the upper and lower flywheels 9 and 10 are connected to the dynamic pressure type gas bearing mechanism 16 and
20 and the additional dynamic pressure type gas bearing mechanism 22 as well as the magnetic bearing mechanisms 57, 58, 59 are supported. As a result, regardless of the rotational speed of the upper and lower flywheels 9, 10, the upper and lower flywheels 9, 10 can always be reliably supported.

Since these magnetic bearing mechanisms 57, 58, 59 are auxiliary, the magnetic force applied to the upper and lower flywheels 9, 10 in advance is relatively small. However, it is not preferable that these magnetic forces adversely affect the interaction between the upper and lower annular electromagnetic coils 7, 8 and the permanent magnets 11, 12. Therefore, the upper and lower flywheels 9 and 10 and the corresponding permanent magnets 11 and 1 respectively.
2 and the annular magnetic shields 60 and 61 are respectively arranged.

Still referring to FIG. 5, a rotation stopping device 63 made of, for example, an airbag is provided in the annular member 6 on the symmetry plane JJ. The rotation stop device 63 is normally kept inactive, but when the rotation stop device 63 is operated and the airbag is deployed, the upper and lower flywheels 9 and 10 are pressed against each other, and as a result, the upper and lower flywheels 9 and 10 are pressed. The rotation of the lower flywheels 9, 10 is stopped immediately.

For example, when the housing 2 is damaged during a vehicle collision and the upper and lower flywheels 9 and 10 jump out of the housing inner space 2a, the upper and lower flywheels 9 and 10 may store large energy. Secondary disaster may occur. On the other hand, since the upper and lower flywheels 9 and 10 rotate in opposite directions to each other, the upper and lower flywheels 9 and 10 rotate.
The upper and lower flywheels 9,
10 can be stopped quickly. That is, the energy stored in the upper and lower flywheels 9 and 10 can be quickly released.

Therefore, in this embodiment, the upper and lower flywheels 9 and 10 are pressed against each other by operating the rotation stop device 63 at the time of an abnormality, for example, at the time of a vehicle collision, whereby the upper and lower flywheels 9 and 10 are stored. Energy is released quickly. As a result, a secondary disaster is prevented from occurring. Also, in this embodiment, the rotation stop device 63 holds the upper and lower flywheels 9, 10 in the housing interior space 2a during operation, thus further preventing a secondary disaster from occurring. Other configurations and operations of the energy storage device 1 are the same as those of the embodiment of FIG.

[0043]

As described above, the inertial mass can be supported in a non-contact manner without lowering the energy conversion efficiency, so that the durability of the energy storage device can be increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an energy storage device.

FIG. 2 is a top view of the upper and lower flywheels.

FIG. 3 is a diagram schematically showing an upper and lower flywheel and a housing inner wall surface.

FIG. 4 is a diagram schematically showing an upper flywheel and an inner wall surface of a housing.

FIG. 5 is a longitudinal sectional view of an energy storage device according to another embodiment.

FIG. 6 is a top view of the upper and lower flywheels according to the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Energy storage device 2 ... Housing 2b ... Housing inner wall surface 9 ... Upper flywheel 10 ... Lower flywheel 16, 18, 20 ... Dynamic pressure type gas bearing mechanism 22, 24 ... Additional dynamic pressure type gas bearing mechanism K ... Rotation axis

Claims (4)

[Claims] 1. An energy storage device comprising a pair of inertial masses rotatably supported around a common rotation axis housed in a housing, and rotating the inertial masses in opposite directions to store energy. An energy storage device, wherein a dynamic pressure type gas bearing mechanism is formed between each inertial mass body and an inner wall surface of the housing, and the inertial mass body is supported by the housing. 2. The dynamic pressure type gas bearing mechanism is formed between an outer peripheral surface of each inertial mass body and an inner wall surface of the housing.
An energy storage device according to claim 1. 3. The energy storage device according to claim 2, wherein an outer peripheral surface of each inertial mass body is inclined with respect to the rotation axis. 4. The pair of inertial masses are arranged adjacent to each other, and an additional hydrodynamic gas bearing mechanism is formed between the inertial masses so that the inertial masses are supported by each other by other inertial masses. The energy storage device according to claim 1.