JPH11206042A - Energy storage apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain small rotating loss for an inertial mass body by maintaining an internal space in a housing to a large negative pressure condition. SOLUTION: A flywheel rotatably supported around in a rotating axis K-K rotation is accommodated inside a housing 2. An upper part 10a of the rotating axis of the flywheel is extended up to the external space 2c of housing, via a through-hole 2b of the housing 2. In a housing external space 2c, air is injected towards the circumferential surface 10aa of the upper part from an air nozzle 13b which is arranged on a vertical surface J-J perpendicular to the rotating axis K-K, and the upper part 10aa is supported by a radial bearing which consists of an air bearing 11b. An injection line L of the air nozzle 13b is tilted with respect to the vertical surface J-J, so that almost all the air injected from the air nozzle 13b collides with the circumferential surface 10aa of the upper part. Thereafter, the air is made to advance in a direction so as to have from a gap 18 between the upper part 10a and the internal surface of the through-hole 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A rotary shaft portion of an inertial mass body accommodated in a housing extends to a housing outer space through a through hole in a housing wall surface, and on a vertical surface perpendicular to an axis of the rotary shaft portion in the housing outer space. There is known an energy storage device in which a working fluid is ejected from a working fluid nozzle disposed in a rotary shaft toward a peripheral surface of the rotating shaft so that the rotating shaft is supported by a radial bearing composed of a fluid bearing (Japanese Patent Application Laid-Open No. Sho 56).
153141). In this energy storage device, the inertial mass is supported by a non-contact type fluid bearing, so that the rotational loss of the inertial mass is minimized.

[0003]

In order to reduce the rotational loss of the inertial mass body, it is effective to maintain the internal space of the housing at a negative pressure. However, in the above-described energy storage device, the working fluid injected from the working fluid nozzle flows into the housing internal space through the gap formed between the rotating shaft and the inner peripheral surface of the through hole, and as a result, the housing internal space is sufficiently negatively charged. There is a problem that the pressure cannot be maintained.

If a seal member is provided in a gap between the rotating shaft and the inner peripheral surface of the through hole, the flow of the working fluid into the housing internal space is reduced. However, in this case, it is necessary to increase the contact pressure between the sealing member and the rotating shaft in order to maintain the housing internal space at a sufficient negative pressure. As a result, the rotational loss of the inertial mass body cannot be kept small.

[0005]

According to the present invention, a rotary shaft of an inertial mass body accommodated in a housing extends to a space outside the housing through a through hole in a wall surface of the housing. The working fluid is ejected from a working fluid nozzle, which is arranged on a vertical plane perpendicular to the axis of the rotating shaft in the outer space of the housing, toward the peripheral surface of the rotating shaft, and the rotating shaft is supported by a radial bearing composed of a fluid bearing. In the energy storage device, the ejection axis of the working fluid nozzle is inclined with respect to the vertical plane, and almost all the working fluid ejected from the working fluid nozzle collides with the peripheral surface of the rotating shaft, and then moves away from the housing. To make progress. That is, the working fluid flowing into the housing internal space is reduced through the gap between the rotating shaft portion and the inner peripheral surface of the through hole, and a negative pressure is generated between the gap and the working fluid nozzle, and this negative pressure acts on the gap. As a result, the interior space of the housing is maintained at a large negative pressure.

[0006]

FIG. 1 shows a case where an energy storage device according to the present invention is applied to a vehicle. However, it is also possible to place the energy storage device according to the invention above or below ground. Referring to FIG. 1, 1 is an energy storage device, 2 is a housing defining a cylindrical internal space 2a, 3 is a fixture for fixing the housing 2 to, for example, a vehicle body, 4 is a protection attached to an outer wall of the housing 2. Walls 5 and 5 denote vacuum pumps for maintaining the housing internal space 2a at a negative pressure, respectively.

A flywheel 6 rotatably supported around a rotation axis KK extending in a vertical direction is accommodated in the housing internal space 2a. The flywheel 6 has a substantially inverted cup shape, and a permanent magnet 7 is attached to an inner peripheral surface 6 a of the flywheel 6. Permanent magnet 7
The three-phase coil 9 and the back yoke 9a supported by the coil holder 8 are disposed so as to face this. The coil holder 8 is fixed to the housing 2. Further, the housing 2, the flywheel 6, the permanent magnet 7, and the three-phase coil 9 are formed symmetrically with respect to the rotation axis KK.

A rotary shaft 10 is formed on the flywheel 6 located on the rotary axis KK. This rotating shaft 10
The upper portion 10a extends to the housing outer space 2c via a through hole 2b penetrating the housing 2 wall surface. A radial bearing 11 is formed between an upper portion 10a of the rotating shaft 10 and the housing 2 facing the same, and a lower portion 10b of the rotating shaft 10 and the housing 2 facing the same.
A spherical thrust bearing 12 is formed between them, so that the flywheel 6 is supported by the housing 2 via these bearings 11, 12.

That is, as shown in FIG. 1, the radial bearing 11 includes a ball bearing 11a provided in the housing inner space 2a and an air bearing 11b provided in the housing outer space 2c. Referring to FIGS. 1 and 2, an annular air chamber 13 fixed to the outer peripheral surface of the housing 2 is formed around the upper portion 10a of the housing outer space 2c. The air chamber 13 is provided on the one hand with an air supply pipe 13a.
On the other hand, is connected to an annular air nozzle 13b arranged on a vertical plane JJ perpendicular to the rotation axis KK and extending toward the peripheral surface 10aa of the upper part 10a. Is done. The injection axis L of the air nozzle 13b is inclined with respect to the vertical plane JJ so as to contract in a direction away from the housing 2.

On the other hand, as shown in FIG.
The tip of the lower portion 10b located on K is a spherical tip 1
5 are formed. A hemispherical concave portion 16 filled with oil is formed on the rotation axis KK of the housing 2, and the spherical tip portion 15 is received in the concave portion 16. Thus, a spherical thrust bearing 12 is formed between the housing 2 and the lower part 10b. Further, a plurality of grooves 17 for generating dynamic pressure are formed spirally on the outer peripheral surface of the spherical tip portion 15 of the lower portion 10b. These grooves 17 extend in the direction opposite to the rotation direction of the flywheel 6 from the center of the tip portion 15 toward the peripheral edge when viewed from below.

As shown in FIG. 2, a peripheral surface 10aa of an upper portion 10a substantially parallel to the rotation axis KK has an annular pressure receiving surface 10ab inclined above the rotation axis KK above the air nozzle 13b. Connected to. The annular pressure receiving surface 10ab expands in a direction away from the housing 2. Still referring to FIG.
A slight gap 18 is formed between a and the inner peripheral surface of the through hole 2b. Therefore, an annular mechanical seal 19 is provided between the peripheral surface of the air chamber 13 and the upper peripheral surface 10aa in order to prevent the housing internal space 2a from communicating with the housing external space 2c via the gap 18.

Next, the operation of the energy storage device 1 of FIG. 1 will be described. When electric energy is supplied to the three-phase coils 9 from an electric energy source (not shown), the flywheel 6 is actuated by the interaction between the magnetic field formed by the three-phase coils 9 and the magnetic field of the permanent magnet 7 attached to the flywheel 6. It is rotated about the rotation axis KK. Even after the supply of energy to the three-phase coil 9 from the electric energy source is stopped, the flywheel 6 continues to rotate, so that the electric energy is stored in the energy storage device 1 in the form of kinetic energy. Alternatively, the upper portion 10 of the rotating shaft portion 10 in the housing outer space 2c via a clutch (not shown)
When a is connected to the kinetic energy source, the flywheel 6 is rotated. Even after the clutch is released, the flywheel 6 continues to rotate, so that kinetic energy is stored in the energy storage device 1 in the form of kinetic energy. In either case, the housing interior space 2a is maintained at a negative pressure by the vacuum pump 5, and
Is kept small.

On the other hand, when the energy stored in the energy storage device 1 is to be output, the three-phase coil 9 is electrically connected to an electric load such as an electric motor.
As a result, the kinetic energy of the flywheel 6 is converted into electric energy and output. Alternatively, the upper part 10a is connected to a mechanical load via a clutch. In this case, the kinetic energy of the flywheel 6 is output in the form of kinetic energy. As the integrated energy output from the energy storage device 1 increases, the rotation speed of the flywheel 6 gradually decreases, and when all the energy is output, the rotation of the flywheel 6 stops.

When the rotational speed of the flywheel 6 is low, the flywheel 6 rotates while the spherical tip 15 abuts on the peripheral surface of the recess 16. In this case, the oil in the recess 16 acts as a lubricating oil. When the rotation speed of the flywheel 6 increases, a dynamic pressure is generated in the concave portion 16 by the groove 17 of the spherical tip 15, and the dynamic pressure causes the spherical tip 15.
A repulsive force, that is, a supporting force, is generated between the recess 16 and the recess 16. In this case, the spherical tip 15 is slightly separated from the recess 16 by the repulsive force, that is, the flywheel 6 is supported without contact. Therefore, the rotation loss of the flywheel can be reduced, and the energy storage device 1
Durability can be increased. When the dynamic pressure generated in the spherical thrust bearing 12 increases and the flywheel 6 separates from the housing 2, the spherical thrust bearing 12 constitutes a dynamic pressure type fluid bearing.

As the rotational speed of the flywheel 6 increases, the dynamic pressure generated in the spherical thrust bearing 12 increases. Therefore, as the rotational speed of the flywheel 6 increases, the supporting force of the flywheel 6 increases. As a result, even when the rotation speed of the flywheel 6 is high, the flywheel 6 can be reliably supported, and thus the amount of energy that can be stored in the energy storage device 1 can be increased.

On the other hand, the compressed air as the working fluid discharged from the air pump 14 flows into the air chamber 13 and is then injected from the air nozzle 13b over the entire circumference of the upper portion 10a. As a result, the air flow is
A collision with aa generates a radial support force of the upper portion 10a, and thus an air bearing 11b is formed between the upper portion 10a and the housing 2.

In this case, the injection axis L of the air nozzle 13b
Contracts in the direction away from gap 18
Since it is inclined with respect to J, almost all of the air injected from the air nozzle 13b collides with the upper partial peripheral surface 10aa and then travels away from the gap 18 without going to the gap 18. As a result, the air injected from the air nozzle 13b is prevented from flowing into the housing internal space 2a through the gap 18. Therefore, a large negative pressure in the housing internal space 2a can be maintained, and thus the rotation loss of the flywheel 6 can be reduced.

Further, at this time, a negative pressure is generated between the air nozzle 13b and the gap 18, or more precisely, between the air nozzle 13b and the mechanical seal 19 due to the air flow from the air nozzle 13b. Applied to seal 19. As a result, even if the contact pressure of the mechanical seal 19 is reduced, a large negative pressure in the housing internal space 2a can be maintained, and thus the rotation loss of the flywheel 6 can be further reduced.

After colliding with the upper partial peripheral surface 10aa, the airflow that has proceeded upward along the upper partial peripheral surface 10aa subsequently collides with the pressure receiving surface 10ab. As a result, the upper part 10
A vertical upward supporting force acts on a, and the supporting force further reduces the rotational loss of the upper portion 10a. In this case, a thrust fluid bearing is formed between the upper part 6 and the housing 2.

In the above embodiment, the clutch is provided in the housing outer space 2c. However, it is also possible to provide a clutch in the housing interior space 2a so that the rotating shaft of the power transmission means connecting this clutch to a kinetic energy source or a mechanical load extends through the through hole 2b of the housing 2. In this case, the rotating shaft of the power transmission means is supported by the housing 2 via the air bearing 11b.

A belt-type continuously variable transmission (CVT), a fluid coupling, an electric motor, and the like can be used to drive the flywheel. These are used depending on whether the flywheel is rotating at a low speed or at a high speed. And the efficiency will be the best. Therefore, a CVT or a fluid coupling and an electric motor can be selectively used.

[0022]

According to the present invention, the internal space of the housing can be maintained at a large negative pressure, so that the rotational loss of the inertial mass body can be kept small.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged sectional view of an upper portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Energy storage device 2 ... Housing 2a ... Housing inner space 2b ... Through hole 2c ... Housing outer space 6 ... Flywheel 10a ... Upper part of a rotating shaft part 11b ... Air bearing 13b ... Air nozzle J ... Vertical plane K ... Rotating axis L: injection axis

Claims (1)

[Claims] 1. A rotating shaft portion of an inertial mass body accommodated in a housing extends to a housing outer space through a through hole in a housing wall surface, and is perpendicular to an axis of the rotating shaft portion in the housing outer space. In an energy storage device in which a working fluid is ejected from a working fluid nozzle disposed on a surface toward the peripheral surface of the rotating shaft and the rotating shaft is supported by a radial bearing composed of a fluid bearing, An energy storage device in which the injection axis is inclined with respect to the vertical plane so that almost all of the working fluid injected from the working fluid nozzle collides with the peripheral surface of the rotating shaft portion and then travels away from the housing.