JPH08182228A - Power storing unit - Google Patents

Abstract

PURPOSE: To obtain a power storing unit in which a rotor can be rotated at a high speed exceeding the eigenvalue of primary bending by integrally providing flywheels with a rotary shaft at the opposite ends thereof and mounting a generator/motor on the rotary shaft between the flywheels. CONSTITUTION: Horizontal planar flywheels 2, 3 are provided fixedly at the upper and lower ends of a vertical shaft 1 and when a rotor 4 is rotating in the operational rotating region, electric energy is converted into rotational kinetic energy which is stored in the flywheels 2, 3. Since the flywheels are provided at the opposite ends of the rotary shaft, the eigenvalue of primary bending is branched significantly and thereby the forward rotational component increases significantly while the rearward rotational component decreases significantly as the revolutions per minute (r.p.m.) increases. Consequently, the critical speed where a transportation line intersects the rearward rotational component of the eigenvalue of primary bending lowers and the transportation line does not intersect the forward rotational of the eiqenvalue of primary bending even if the r.p.m. increases. With such structure, the rotor can be rotated at an r.p.m. exceeding the eigenvalue of primary bending.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power storage device for converting surplus power into rotary kinetic energy of a flywheel and storing it.

[0002]

2. Description of the Related Art As an electric power storage device of this kind, a flywheel is integrally formed at one position at a central portion or an end portion of a rotating shaft which is non-contact supported by a superconducting bearing and / or a magnetic bearing and is rotated by a generator motor. It is known that it is provided in.

[0003]

The rotational kinetic energy E of the rotating body is expressed by the following equation, where I _p is the polar moment of inertia of the entire rotating body and ω is the rotational angular velocity of the rotating body.

[0004] ^{_{E = I p · ω 2/}} 2 From this equation, in order to increase the rotational kinetic energy stored in the flywheel, increase the polar moment of inertia I _p of the whole rotary body, the rotation angular velocity of the rotary body It can be seen that ω, that is, the number of revolutions should be increased. Further, it is desirable to increase the energy storage density per unit weight of the flywheel to improve the energy storage efficiency. For that purpose, increasing the rotational angular velocity ω is more effective than increasing the polar moment of inertia I _p. There is.

However, increasing the number of rotations of the rotating body has a problem in terms of the critical speed of the rotating body, as described below. That is, the critical velocity of the rotating body includes a rigid primary primary critical velocity based on the rigid primary first mode, a rigid secondary secondary critical velocity based on the rigid secondary mode, and a primary bending critical velocity based on the primary bending mode. Fig. 7 (c) shows the relationship between the rotation speed and the rotation speed of the rotating body. Figure 7
In (c), the horizontal axis represents the rotation speed (rpm) and the vertical axis represents the eigenvalue (critical speed) (Hz). Also, FIG. 7 (c)
In the figure, a transportation line (rotational acceleration line) from a point where the rotation speed is 0 to a point where the rotation speed is the maximum is shown. As shown in Figure 7 (c),
Due to the unique gyro effect in the rotating body, eigenvalue branching occurs, and a forward component and a backward component occur in each eigenvalue.
The critical speed is the number of revolutions at which the carrying line intersects with some branched eigenvalues, but the critical speed at which the carrying line intersects with the primary bending eigenvalue is a particular problem. The rotating body was rotated within the range not exceeding. Since the number of rotations of the rotating body is thus limited, the flywheel needs to be large in order to increase the polar moment of inertia I _p of the entire rotating body. However, if this is done, the device becomes large and the flywheel unit becomes large. There is a problem that the energy storage density per weight becomes small.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a power storage device capable of rotating a rotating body at a high speed exceeding the primary bending characteristic value.

[0007]

In the electric power storage device according to the present invention, flywheels for accumulating rotary kinetic energy are integrally provided at both ends of the rotary shafts, and the flywheels between the flywheels are integrated. It is characterized in that a generator motor is provided in a part.

[0008]

Since the flywheels are provided at both ends of the rotary shaft, the polar moment of inertia I _p of the entire rotary body including the rotary shaft and the flywheel becomes large, and the rotary motion accumulated in the rotary body is correspondingly increased. Energy becomes large. Also,
Since the flywheels are provided at both ends of the rotary shaft, the tilt inertia moment I _r of the entire rotary body becomes large, and its increase amount is considerably larger than the increase amount of the polar inertia moment I _p . Therefore, the ratio (I _p / I _r ) of the polar moment of inertia I _p and the tilt moment of inertia I _r becomes smaller than that of the conventional one. Although the ratio (I _p / I _r ) becomes smaller, the backward component of the primary bending eigenvalue of the rotating body greatly decreases as the rotation speed increases, and the leading component of the primary bending eigenvalue becomes the rotation speed. It will increase greatly with the increase of. For this reason, when the maximum number of rotations of the rotating body is increased, the carrying line exceeds the rearward component of the primary bending eigenvalue at a low number of rotations, and even if the number of rotations is considerably high, the carrying line is in front of the primary bending eigenvalue. Does not intersect with surrounding components. Therefore,
It is possible to rotate the rotating body at a high rotation speed that exceeds the backward component of the primary bending eigenvalue. Since the number of rotations of the rotating body can be increased, the rotational kinetic energy accumulated in the rotating body can be further increased. Also,
Since the rotational speed of the rotating body can be increased, the energy storage density per unit weight of the flywheel can be increased.

[0009]

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

FIG. 1 schematically shows a main part of a power storage device.

The power storage device comprises a rotating body (4) having horizontal disk-shaped flywheels (2) and (3) fixedly provided on the upper and lower ends of a vertical rotating shaft (1), respectively. Two sets of upper and lower superconducting bearings (5) and (6) for non-contact support of 4) in the axial direction (vertical direction) and radial direction, non-contact in the radial direction of the rotating body (4) at start-up and operation stop. Two sets of upper and lower control type radial magnetic bearings for supporting,
It is equipped with an initial positioning device (9) for positioning the rotating body (4) at startup, as well as a generator-motor (10), most of which are located above the horizontal base (11). It is located in the chamber (12). Vacuum chamber (1
2) Multiple members (13) (14) (15) (16) (1) on the base (11) in
A vertical housing (19) consisting of (7) and (18) is provided, and the rotating body (4) is vertically arranged with a gap in the center of the housing (19) so that it can be slightly moved up and down. ing. A vertical cylindrical member (20) is provided below the base (11), and most of the initial positioning device (9) is this cylindrical member (20).
It is located inside.

Each of the flywheels (2) and (3) has an inner annular portion fixed to the rotating shaft (1) and made of, for example, an aluminum alloy.
An outer annular portion (22) made of, for example, CFRP (composite fiber reinforced plastic) is integrally fixed to the outside of (21). The upper flywheel (2) is in a space surrounded by a horizontal plate-shaped fifth housing member (17) on the upper part of the housing (19) and an inverted cup-shaped sixth housing member (18) fixed thereon. It is located in. Lower flywheel (3)
Is a base (11) and an inverted cup-shaped first fixed on it.
It is arranged in the upper part in the space surrounded by the housing member (13).

Details of the upper superconducting bearing (5) are shown in FIGS.

The upper superconducting bearing (5) faces a horizontal annular rotating permanent magnet portion (23) fixedly provided on the upper flywheel (2) of the rotating body (4) and its upper surface. Thus, it is composed of the superconductor portion (24) fixedly provided in the housing (19).

The rotating permanent magnet portion (23) is provided with a flange portion (25) fixed to the upper end of the rotating shaft (1) so as to contact the upper surface of the inner portion of the upper flywheel (2). The flange portion (25) is integrally fixed with an annular portion (27) made of CFRP, for example, on the outside of the inner non-magnetic plate portion (26) made of a non-magnetic material such as aluminum alloy or non-magnetic stainless steel. It is located inside the through hole in the center of the top wall of the sixth housing member (18). On the upper surface of the non-magnetic plate portion (26), a plurality of annular recessed grooves (29) partitioned by a circular partition wall (28) are concentrically formed. In each recess (29),
Annular yoke member (3) consisting of an annular permanent magnet (30) and a ferromagnetic material
1) and are fixed so that the permanent magnet (30) is fitted outside. The outer circumference of the permanent magnet (30) has a groove (29).
It is press-fitted into the outer peripheral wall or the inner peripheral portion of the partition wall (28). The inner peripheral portion of the yoke member (31) is press-fitted into the partition wall (28) on the inner peripheral side of the groove (29) or the outer peripheral portion of the wall. Then, the inner peripheral portion of the permanent magnet (30) and the outer peripheral portion of the yoke member (31) in the same groove (29) are loosely fitted to each other, and there is little or no gap between them. It is open. The positions of the annular permanent magnet (30) and the annular yoke member (31) may be reversed in each annular groove (29). Further, the partition wall (28) may be omitted and only the annular yoke member (31) may be arranged between the annular permanent magnets (30). Each permanent magnet (30) is equally divided into a plurality of segments (30a) in the circumferential direction, and magnetic poles are formed on the inner peripheral side and the outer peripheral side. The permanent magnets (30) are arranged so that the magnetic poles of the two permanent magnets (30) adjacent in the radial direction have the same polarity. That is, the 1st, 3rd, and 5th permanent magnets (30) from the inside have the S pole on the inner circumference side and the N pole on the outer circumference side, and the 2nd and 4th permanent magnets (30) have the N pole on the inner circumference side and the S pole on the outer circumference side. Has become. The permanent magnet (30)
Is divided into a plurality of segments (30a) in the circumferential direction because magnetic poles cannot be formed on the inner peripheral portion and the outer peripheral portion of the permanent magnet if the permanent magnet is an annular one body. Since the permanent magnets (30) are concentrically arranged with respect to the rotation axis of the rotating body (4), the magnetic flux distribution around the rotation axis does not change due to rotation.

The superconductor portion (24) is provided with a horizontal annular cooling case (32) made of a non-magnetic material such as copper alloy or non-magnetic stainless steel. The cooling case (32) is fixed at its outer peripheral portion to the upper surface of the inner peripheral portion of the top wall of the sixth housing member (18) via a heat insulating material (33), and extends above the permanent magnet portion (23). There is. An annular superconductor (34) is fixedly arranged in the space inside the cooling case (32). Cooling case (3
The space in 2) is connected to a cooling device (not shown) via the cooling fluid supply pipe (35) and the discharge pipe (36).
(35) is circulated through the space in the cooling case (32) and the discharge pipe (36), whereby the superconductor (34) is cooled. The superconductor (34) is a type 2 superconductor, for example, an yttrium-based high temperature superconductor, YBa ₂
A normal conductor (Y ₂ B) is formed inside the bulk made of Cu ₃ O _7-x.
a ₁ Cu ₁ ) are mixed uniformly, and the permanent magnet (3
It has the property of internally restraining the magnetic flux generated from (0). Then, the superconductor (34) is located at a separated position where the magnetic flux of the permanent magnet (30) enters a predetermined amount, and the distribution of the invading magnetic flux does not change due to the rotation of the rotating body (4). ) Is arranged to face.

Details of the lower superconducting bearing (6) are shown in FIG.

The lower superconducting bearing (6) faces the lower surface of a horizontal annular rotating permanent magnet portion (37) fixedly provided under the lower flywheel (3) of the rotating body (4). A superconductor part (38) fixedly provided on the housing (19),
The first housing member further comprises a fixed permanent magnet portion (39) fixedly provided in the housing (19) so as to face the rotating permanent magnet portion (37) from below the superconductor portion (38). (1
It is located at the bottom of 3).

The rotating permanent magnet portion (37) is fixed to the lower end of the rotating shaft (1) so as to contact the lower surface of the inner portion of the lower flywheel (3). The superconductor part (38) is fixed to the support member (40) fixed on the base (11) via a heat insulating material (41). Rotating permanent magnet part (37) and superconductor part (38)
Indicates that the rotating permanent magnet part (23) and the superconductor part (24) of the upper superconducting bearing (5) are turned upside down. Is omitted.

The fixed permanent magnet portion (39) has a non-magnetic flange portion (43) fixed on the base (11) via a support member (42). An annular recess (44) is formed on the upper surface of the flange (43) leaving the outer peripheral portion thereof, and an annular yoke member (45) made of a plurality of ferromagnetic bodies is formed in the recess (44).
And a plurality of annular permanent magnets (46) sandwiched between them are fitted and fixed. The number of permanent magnets (46) is the same as the number of permanent magnets (30) of the rotating permanent magnet section (37), and the permanent magnets (46) are almost opposite to the permanent magnets (30) of the rotating permanent magnet section (37). It is arranged to. The permanent magnet (46) has the same structure as the permanent magnet (30) of the rotating permanent magnet section (37) and is equally divided into a plurality of segments (46a) in the circumferential direction. The arrangement of the magnetic poles of the permanent magnet (46) is the same as that of the rotating permanent magnet section (37), and the magnetic poles of the permanent magnets (30) (46) corresponding to the upper and lower sides have the same polarity and are repulsed from each other. ing.

Details of the upper magnetic bearing (7) are shown in FIG.

The upper magnetic bearing (7) includes eight electromagnets (47x) (47y) and four displacement sensors (fixed inside the fourth housing member (16) having a substantially cylindrical shape in the upper part of the housing (19). Four
It has 8x) (48y). Assuming that the two radial axes that are orthogonal to each other are the X axis and the Y axis, the four X-axis direction electromagnets (47x) are arranged so as to attract the rotating body (4) from both sides in the X-axis direction, and the four Y-axis axes are arranged. Axial electromagnet (47y) is a rotating body
(4) is arranged so as to be sucked from both sides in the Y-axis direction. Each displacement sensor (48x) (48y) is a corresponding electromagnet
It is located near (47x) (47y), and the two X-axis displacement sensors (48x) detect the amount of displacement of the rotating body (4) in this direction in the X-axis. Sensor (48y)
Thus, the displacement amount of the rotating body (4) in this portion in the Y-axis direction is detected.

The lower magnetic bearing (8) is the first housing member.
Thick cylindrical second housing member fixed on (13)
It is provided inside (14). Since the lower magnetic bearing (8) is similar to the upper magnetic bearing (7), the corresponding parts are designated by the same reference numerals and detailed description thereof will be omitted.

Although not shown, the electromagnets (47x) (47y) and the displacement sensors (48x) (48y) of the magnetic bearings (7) (8) are connected to the magnetic bearing control device, and by this control device, Based on the outputs of the displacement sensors (48x) (48y), the value of current flowing through the electromagnets (47x) (47y), that is, the attractive force is controlled, and as a result, the position of the rotating body (4) in the radial direction is controlled.

Since the magnetic bearings (7) and (8) and the control device for the magnetic bearings are publicly known, further detailed description will be omitted.

The generator-motor (10) is fixed inside the rotor (49) attached to the rotating body (4) and the cylindrical third housing member (15) in the middle of the housing (19) around the rotor (49). And a stator (50) provided in the shape of a circle. The generator motor (10)
It operates as an electric motor when storing electric power and as a generator when extracting electric power.

Normally, the rotating body (4) is not in contact with the upper end of the fourth housing member (16) and the through hole in the top wall of the first housing member (13), and the rotating body (4) is in an emergency. Touch-down bearings (51) and (52), which are rolling bearings that support the bearings, are provided.

The initial positioning device (9) is constructed as follows.

In the guide hole formed in the intermediate portion of the cylindrical member (20), a cylindrical elevating body (53) which is moved up and down by an appropriate driving means such as a linear motor (not shown) is guided, A horizontal disc (54) is fixedly provided on the upper part of the body (53). Vertical support shaft (55) concentric with the rotating body (4)
Is fixed to the center of the upper surface of the disc (54) so that it can be moved up and down by being guided by the linear bearing (56) provided in the through hole of the base (11) when the elevating body (53) is moved up and down. It has become. A plurality of balls (57) for receiving the lower end surface of the rotating shaft (1) are attached to the outer peripheral portion of the upper end surface of the support shaft (55). A pendant cylindrical portion (11a) is integrally formed on the lower surface of the base (11) around the linear motion bearing (56), and the lower end of the cylindrical portion (11a) and the outer peripheral surface of the upper surface of the disc (54) are formed. Fixed ring member (5
A bellows (59) is installed between it and 8). And
Disc (54), ring member (58), bellows (59) and cylinder
The space surrounded by (11a) is communicated with the vacuum chamber (12) above the base (11) and is maintained in a vacuum state.

A stopper (60) for restricting the rise of the rotating body (4) is fixed around the rotating body (4) slightly below the lower touchdown bearing (52).

The power storage device described above is put into operation in the following manner.

In the operation stopped state, the rotating body (4) is supported by the touchdown bearings (51) and (52) and stopped at the lower stop position. When starting the operation, first make the inside of the vacuum chamber (12) a vacuum state and raise the support shaft (55) of the initial positioning device (9) to move the rotating body (4) to a predetermined set position. Lift and perform initial positioning of the rotating body (4) in the axial direction. The setting position of this rotating body (4) is
It is a position slightly above the position of the rotating body (4) during rotation.
Further, the upper and lower magnetic bearings (7) and (8) are driven to perform the initial positioning of the rotating body (4) in the radial direction. After the initial positioning of the rotating body (4) is completed, the cooling device circulates the cooling fluid in the cooling cases (32) of the upper and lower superconducting bearings (5) and (6) to cool the superconductor (34). Then, the second-type superconducting state is maintained. Then, most of the magnetic flux generated from the permanent magnets (30) of the rotating permanent magnet parts (23) (37) enters the inside of the superconductor (34) and is restricted (pinning phenomenon). here,
Since the normal conductor particles are uniformly mixed in the superconductor (34), the distribution of the magnetic flux penetrating the inside of the superconductor (34) becomes constant, and therefore the superconductor (34) is Permanent magnet
The rotating body (4) is restrained together with (30). Therefore, the rotating body (4) is supported in the axial direction and the radial direction in an extremely stable state. At this time, the magnetic flux penetrating the superconductor (34) does not become a resistance that hinders rotation as long as the magnetic flux distribution is uniform and unchanged with respect to the rotation axis. When the rotating body (4) is supported by the superconducting bearings (5) (6) in this way, the supporting shaft (55) of the initial positioning device (9) is lowered to the lower end position, and the rotating body
Remove support for (4). When the support shaft (55) descends,
Although (4) slightly descends due to its own weight, it stops at a position where the downward force due to its own weight balances the axial support force of the superconducting bearings (5) (6), and then the support shaft (55) It moves downward from the rotating body (4) to the lower end position. As a result, the rotating body (4) is non-contact supported by the superconducting bearings (5) (6) and the magnetic bearings (7) (8). At this time, the lower superconducting bearing
The permanent magnet (30) of the rotating permanent magnet section (37) of (6) receives an upward repulsive force from the permanent magnet (46) of the fixed permanent magnet section (39),
As a result, a part of the weight of the rotating body (4) is supported. When the rotating body (4) is supported in a non-contact manner, the generator motor (10) is started and the rotating body (4) is rotated. At this time, the rotation speed of the rotating body (4) is controlled by an inverter (not shown), and the rotating body (4) is efficiently accelerated to the operating rotation range (stable rotation range). Even if resonance occurs until the rotating body (4) reaches the operating rotation range, the magnetic bearings (7) and (8) prevent the occurrence of runout. When the rotating body (4) reaches the operating rotation range, the rotating body (4) is maintained at a predetermined rotation speed (for example, 40000 rpm) in the operating rotation range, and the driving of the magnetic bearings (7) (8) is stopped. As a result, there is no support in the radial direction by the magnetic bearings (7), (8). Even if the radial bearings of the magnetic bearings (7) (8) are lost, the rotating body (4) is a superconducting bearing.
(5) It is supported by (6) in the axial and radial directions and continues to rotate.

While the rotating body (4) is rotating in the operating rotation range, electric energy is converted into rotational kinetic energy and stored in the flywheels (2) and (3).

When a power failure occurs while the rotating body (4) is rotating in the operating rotation range, the generator motor (10) is stopped, but the flywheel (2) (3) causes the rotating body (4) to rotate. Is slowed down slightly but is continuously rotated. as a result,
The generator motor (10) operates as a generator, and the electric power obtained via a converter (not shown) is stored in a storage battery. The electric power stored in the storage battery is sent to an external power consumer product (not shown) and a cooling device for the superconducting bearings (5) and (6). During this period, by operating the generator motor (10) as a generator, a part of the electric power obtained through the converter and stored in the storage battery is sent to the control device of the magnetic bearings (7) (8), The magnetic bearings (7) (8) are driven. Therefore, the runout of the rotating body (4) that occurs at the resonance point before the rotating body (4) stops because the rotational kinetic energy stored in the flywheels (2) (3) decreases and It can be reduced by the magnetic bearings (7) and (8) in the same manner as the time, and the rotating body (4) and the flywheels (2) and (3) will be held in a non-contact state until stopped. As a result, flywheels (2)
The rotational kinetic energy stored in (3) will be efficiently sent to the external power consumer goods as electric energy. In addition, the shake generated before the rotating body (4) is stopped is corrected in the same manner as above.

Even when it is necessary to take out the rotary kinetic energy stored in the flywheels (2) and (3) as electric energy at times other than the time of power failure, the generator motor (10) is stopped, similar to the case of power failure. Then, power energy is supplied to the power consumer goods. In this case also, the rotating body (4) and the flywheels (2) (3) are kept in a non-contact state until stopped, and the rotary kinetic energy accumulated in the flywheels (2) (3) is , Can be efficiently sent as electric energy to external power consumption goods.

In the above power storage device, the flywheel
(2) Since (3) is provided at both ends of the rotating shaft (1), 1
The rotating body can be rotated at a high rotation speed that exceeds the backward component of the next bending eigenvalue. Next, the reason will be described with reference to FIGS. 6 and 7.

FIG. 6 shows three models of the rotating body of the power storage device. FIG. 6A shows the rotating body of the above embodiment.
Flywheel (2) on each end of the rotating shaft (1) as shown in (4)
Fig. 6 (c) is a model in which (3) is provided, Fig. 6 (b) is a model of a conventional rotating body in which a flywheel (62) is provided only at one position at the upper end of the rotating shaft (61), ) Is the flywheel (62) only in one place slightly above the center of the rotary shaft (61)
3A and 3B respectively show models of conventional rotating bodies provided with. The polar moment of inertia I _p for each model in FIG.
The result of calculating the ratio (I _p / I _r ) between the tilt inertia moment I _r and the tilt inertia moment I _r is shown. For the model of (a), the ratio (I _p / I _r ) is 0.27, and (b) ), The ratio (I _p / I _r ) is 0.34, and for the model (c), the ratio (I _p / I _r ) is 0.47.

FIG. 7 shows results obtained by simulating the relationship between the number of rotations of the rotating body and the eigenvalue for each model shown in FIG. Figure 7 (a) is the result for the model in Figure 6 (a), Figure 7 (b) is the result for the model in Figure 6 (b), and Figure 7 (c) is the result for the model in Figure 6 (c). Are shown respectively.

In the conventional model of FIG. 6 (c), although the ratio (I _p / I _r ) is large, the degree of bifurcation of the primary bending eigenvalue is small as shown in FIG. 7 (c). The degree of increase of the forward component and the degree of decrease of the backward component of the primary bending eigenvalue with the increase of the rotation speed are also small. For this reason, the critical speed at which the transport line intersects the backward component of the primary bending eigenvalue becomes high (in this case, about 36000 rpm), and the rotor is rotated at a high rotational speed exceeding the backward component of the primary bending eigenvalue. Then, since the haul line needs to exceed the backward component of the primary bending eigenvalue at this high critical speed,
The control of magnetic bearings is very difficult. Therefore, it is very difficult to rotate the rotating body at a high rotation speed that exceeds the backward component of the primary bending eigenvalue. Further, even if the rotating body is rotated at a high rotation speed (for example, 40000 rpm) beyond the backward component of the primary bending eigenvalue, the rotating body is supported only by the superconducting bearing in the operating state,
Moreover, since the rotational speed in the operating state is relatively close to the critical speed of the backward component of the primary bending eigenvalue, there is a problem that the operation becomes unstable.

In the conventional model of FIG. 6 (b), the ratio (I _p / I _r ) is smaller than that of the model of FIG. 6 (c), but as shown in FIG. The degree of branching of the bending eigenvalue is somewhat large, and the degree of increase of the front-turning component and the degree of decrease of the same-turning component of the first-order bending eigenvalue are considerably small as the number of rotations increases. Therefore, the critical speed at which the transport line intersects with the backward component of the primary bending eigenvalue is still high (in this case, about 30,000 rpm), and as in the case of the model in Fig. 6 (c), the rotating body is placed after the primary bending eigenvalue. It is very difficult to rotate at a high rotation speed that exceeds the rotation component.

As for the model of the above embodiment shown in FIG. 6A, although the ratio (I _p / I _r ) is small, the model shown in FIG.
As shown in (a), the degree of divergence of the primary bending eigenvalue is large, and the degree of increase of the forward component and the degree of decrease of the backward component of the primary bending eigenvalue are large with the increase of the rotation speed.
Therefore, the critical speed at which the haul line intersects with the backward component of the primary bending eigenvalue becomes low (in this case, about 20,000 rp).
m), the carrier line does not intersect with the forward component of the primary bending eigenvalue even when the rotation speed is considerably high. Since the critical speed is low when the transport line exceeds the backward component of the primary bending eigenvalue, control of the magnetic bearing at this time is relatively easy, and the rotating body exceeds the backward component of the primary bending eigenvalue. It is possible to rotate at a high rotation speed. In addition, even in an operating state in which the rotating body is supported and rotated only by the superconducting bearing at a high rotation speed (for example, 40,000 rpm) that exceeds the backward component of the primary bending eigenvalue, the rotation speed in this operating state is the primary bending eigenvalue. The driving speed does not become unstable because it is far from the critical speeds of the rear and front components.

In the above power storage device, the superconducting bearing (5)
The rotary permanent magnet part (23) (37) of (6) is provided with a plurality of annular permanent magnets (30) arranged concentrically in the radial direction, and the inner peripheral side and the outer peripheral side of each permanent magnet (30). A magnetic pole is formed, and two permanent magnets (30) adjacent to each other in the radial direction have the same magnetic pole, and a yoke member made of a ferromagnetic material is provided between the two permanent magnets (30) adjacent to each other in the radial direction. 31) is sandwiched, the magnetic flux is locally concentrated in the portion of the yoke member (31) facing the superconductor (34), and as a result, the superconductor (34)
The magnetic flux penetrating into the superconducting bearing increases, and the load capacity and rigidity of the superconducting bearings (5) and (6) are improved.

However, the permanent magnets of the rotating permanent magnets (23) and (37) of the superconducting bearings (5) and (6) and the fixed permanent magnets (39).
(30) and (46) may have magnetic poles formed at both ends in the axial direction. In this case, the permanent magnet can be made into an annular one piece.

In the above power storage device, the lower superconducting bearing is used.
In (6), part of the weight of the rotating body (4) is supported by the repulsive force between the permanent magnet (30) of the rotating permanent magnet section (37) and the permanent magnet (46) of the fixed permanent magnet section (39). Therefore, the load capacity in the axial direction (gravitational direction) is improved,
It is also possible to support a heavy rotating body that cannot be supported by an ordinary superconducting bearing in which only the rotating permanent magnet section and the superconductor section are opposed to each other.

Fixed permanent magnet part (39) of the lower superconducting bearing (6)
Instead of the above, the fixed permanent magnet part is arranged above the superconductor part (24) of the upper superconducting bearing (5), which attracts the rotating permanent magnet part (23) upward, ) May be partially supported. Also, the upper and lower superconductor bearings
Both (5) and (6) may be provided with a fixed permanent magnet portion for supporting a part of the weight of the rotator (4), or neither of them may be provided.

In the above power storage device, each superconducting bearing
(5) In the rotating permanent magnet part (23) (37) of (6), the flange part
On the outside of the non-magnetic plate portion (26) of (25), a CFRP annular portion (2
7) is fitted, and one set of the annular permanent magnet (30) and the yoke member (31) is assembled in each of the plurality of concentric annular groove (29) on the end surface of the non-magnetic plate portion (26). Has a permanent magnet
(30) and the yoke member (31) can be easily controlled in size, and the permanent magnet (30) is less deformed by centrifugal force during high-speed rotation. Therefore, the operation of the superconducting bearings (5) (6) is stable. In addition, the permanent magnet (30) does not cause centrifugal damage.

The CFRP forming the outer annular portion (27) of the flange portion (25) is lightweight and has a large Young's modulus. And
Since it is lightweight, the centrifugal force acting on the annular portion (27) at the time of high speed rotation is small, and since the Young's modulus is large, the deformation (centrifugal expansion) due to the centrifugal force is small. Since the centrifugal expansion of the annular portion (27) is small as described above, the centrifugal expansion of the non-magnetic plate portion (26) fitted inside the annular portion (27) can be suppressed to a small value.

If a plurality of annular yoke members and annular permanent magnets are alternately fitted in one groove on the end face of the non-magnetic plate portion, the outer yoke members or permanent magnets will be centrifugally expanded. Centrifugal expansion is small because it is close to the wall of the hard non-magnetic plate part, but when a certain yoke member or permanent magnet expands centrifugally, the permanent magnet or yoke member inside it also easily expands centrifugally, so the inner permanent magnet or yoke. The centrifugal expansion of the member is large. Therefore, it is difficult to control the dimensions of the inner permanent magnet or the yoke member. Further, since the inner permanent magnet has a large centrifugal expansion, that is, a large displacement in the radial direction, the radial position of the permanent magnet changes between the initial positioning when the rotor is stopped and the high speed rotation. Especially when the permanent magnet is divided into a plurality of segments in the circumferential direction, a circumferential gap may occur between these segments. For this reason, the magnetic flux distribution due to the permanent magnets changes between initial positioning and high-speed rotation, and the magnetic flux distribution around the rotation axis becomes uneven, which makes the operation of the superconducting bearing unstable. In addition, especially for the inner permanent magnet, a large centrifugal expansion occurs, which may cause centrifugal destruction.

On the other hand, in the rotating permanent magnet parts (23) and (37) of the superconducting bearings (5) and (6) of the power storage device, the permanent magnets are
Since the (30) is press-fitted into the inner peripheral portion of the wall of the non-magnetic plate portion (26) with small centrifugal expansion, the dimensional control of the permanent magnet (30) is easy, and the centrifugal expansion of the permanent magnet (30) is easy. Also, the permanent magnet (30) does not cause centrifugal damage. And since the centrifugal expansion of the permanent magnet (30) is small, even if the permanent magnet (30) is divided into a plurality of segments (30a) in the circumferential direction,
The radial displacement of the permanent magnet (30) is small, and no circumferential gap is formed between the segments (30a). Therefore, the magnetic flux distribution due to the permanent magnet (30) does not change between initial positioning and high-speed rotation, and the magnetic flux distribution around the rotation axis does not become uneven, and the superconducting bearing (5) ( The operation of 6) is stable. Further, since each yoke member (31) is press-fitted into the outer peripheral portion of the wall of the non-magnetic plate portion (26) having a small centrifugal expansion, dimensional control of the yoke member (31) is easy. The yoke member (31) may be press-fitted inside the permanent magnet (30) in the same groove (29). Even in this case, as for the dimension control of the yoke member (31), only the small centrifugal expansion of the one permanent magnet (30) on the outer side needs to be taken into consideration, so that the dimension control is still easy.

In the above embodiment, the rotating body (4) is supported by the superconducting bearings (5) and (6) and the magnetic bearings (7) and (8). It can be applied to the case of supporting only the superconducting bearing or the case of supporting only the magnetic bearing.

[0051]

According to the electric power storage equipment of the present invention, as described above, the rotating body can be rotated at a high rotation speed exceeding the rearward component of the primary bending eigenvalue, and therefore, the rotating body is accumulated. The rotational kinetic energy can be further increased, and the energy storage density per unit weight of the flywheel can be increased.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a power storage device showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view showing a part of the upper superconducting bearing of FIG.

3 is an enlarged plan view showing a part of the rotary permanent magnet portion of FIG. 2. FIG.

FIG. 4 is a vertical cross-sectional view showing a part of the lower superconducting bearing of FIG. 1 in an enlarged manner.

5 is a lateral cross-sectional view showing an enlarged part of the upper magnetic bearing of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing three models of a rotating body.

7 is a graph showing the relationship between the number of rotations and the eigenvalues for the three rotating body models of FIG.

[Explanation of symbols]

 (1) Rotating shaft (2) (3) Flywheel (4) Rotating body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuo Rokkaku, 3-5-8 Minamisenba, Chuo-ku, Osaka City Koyo Seiko Co., Ltd. (72) Takuchi Ueyama 3-5-8 Minamisenba, Chuo-ku, Osaka City Koyo Within Seiko Co., Ltd.

Claims (1)

[Claims] 1. A flywheel for accumulating rotary kinetic energy is integrally provided at both ends of a rotary shaft, and a generator motor is provided at a part of the rotary shaft between the flywheels. And a power storage device.