JPS648224B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention allows surplus power to be distributed at irregular times,
The present invention relates to a flywheel type energy storage device used as a means for storing electric power during normal operation and extracting electric power during a power outage, and in particular relates to improvements in the generator motor portion that converts mechanical energy and electrical energy.

FIG. 2 shows an example of a conventional flywheel type energy storage device. In the same figure, 1
is a rotating shaft, 2 is a casing, 3 is a bearing, and the rotating shaft 1 has a flywheel 4 and a generator motor 5.
A rotor 6 is attached, and this rotor 6 is disposed opposite to a stator 7 of a generator motor 5 fixed to the casing 2 with a gap interposed therebetween.

Examples of the types of generator motors mentioned above include synchronous type, induction type, and in some cases DC type, but Fig. 2 shows a synchronous type generator motor.
The rotor 6 includes a magnet 8, an outer ring 9a and an inner ring 9b fixing the magnet 8, and a rotor core 10.
It is equipped with The magnet 8 is configured to generate a magnetic field with an appropriate number of poles, such as 4 poles, as shown in the figure.
The outer ring 9a and the inner ring 9b are arranged and fixed with adhesive or the like, and these are also fixed to the rotor core 10 in order to secure a magnetic path between the magnetic poles within the rotor 5. In the example of FIG. 2, as shown in FIG. 2b, an interpole spacer 11 made of a non-magnetic material is provided between the magnets 8, but this may be omitted. In addition, rotor core 1
As the material for the outer ring 9a, a laminated wound core or a steel material including ultra-high strength steel is used. When steel material is used, as shown in Fig. 2, it wraps around the outer periphery of the outer ring 9a and the outer ring 9a is released due to the centrifugal force during high-speed rotation. The elongation of the ring 9a can be supported and reinforced by the steel material.

Energy is stored by the flywheel type energy storage device by operating the generator motor 5 as a synchronous motor using a variable speed inverter, and controlling the generator motor 5 at a rotational position detected by an open-loop control or a rotational position detector (not shown) attached to the rotating shaft 1. This is achieved by operating the motor as a brushless motor that controls the operation of the inverter accordingly. On the other hand, the stored energy can be taken out by converting the AC output of the generator motor 5 into DC power through regenerative control of the inverter.

By the way, in order to increase the energy storage density, the flywheel 4 should be rotated as fast as possible, but the flywheel 4 and the rotor 6 of the generator motor 5 should be made independent as in the conventional example shown in FIG. When provided, the length of the rotating shaft 1 becomes long, which tends to be a constraint for increasing the resonance frequency, and there is a certain limit to increasing the speed. Furthermore, since the magnetic material such as ferrite used for the rotor 6 generally has insufficient strength against centrifugal force, it is reinforced with a highly rigid outer ring 9a made of a non-magnetic material, and as described above, the outer ring 9a itself is However, if such a configuration is adopted, the diameter of the rotor 6 will inevitably increase, which will affect the rotational balance of the rotating shaft 1 including the rotor 6 and the flywheel 4. Since the adjustment becomes delicate, the length of the rotating shaft 1 increases, making it even more difficult to increase the rotation speed.

In order to improve these drawbacks, the present invention integrates the rotor of the generator motor into the flywheel, thereby shortening the rotating shaft and making it easier to adjust the rotational balance of the rotating shaft. This makes it possible to rotate the flywheel at high speed and obtain a large energy storage density.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention, in which a circular recess 4 is formed on the inner peripheral edge of the lower surface of the flywheel 4 and is centered around the rotation center of the rotating shaft 1 and faces the stator 7.
A rotor 6 of the generator motor 5 is housed in the recess 4a.

The flywheel 4 is made of a magnetic material, and serves as a rotor core of the rotor 6 in addition to storing energy. Similarly to the conventional device shown in FIG. 2, the rotor 6 is composed of a magnet 8 and an outer ring 9a and an inner ring 9b for supporting and reinforcing the outside and inside of the magnet 8, and these are bonded together with an adhesive or the like as described above. It is housed in a recess 4a of the flywheel 4.

However, since the rotor 6 of the generator motor 5 is housed in the recess 4a of the flywheel 4 which also serves as the rotor core, the assembly work is simplified compared to the conventional arrangement in which the rotor 6 is provided separately. At the same time, it can be expected that the axial length of the rotating shaft 1 can be significantly shortened, and it becomes extremely easy to balance the rotation, thereby making it possible to increase the rotation speed of the flywheel 4. Furthermore, since the flywheel 4 is generally made of a relatively rigid material due to its nature, another reinforcing means can be provided by having the outer ring 9a abutted and supported on the inner peripheral surface of the circular recess 4a. It can be expected to prevent the outer ring 9a from elongating due to centrifugal force, and in this respect as well, higher speeds can be achieved.

In addition, magnet 8 is used as a type of synchronous generator motor.
It goes without saying that similar effects can be obtained in the case of a reactance type structure in which the part is replaced with a magnetic material.

As described above, in the present invention, the flywheel is made of a magnetic material and serves as the rotor core of the rotor, and the flywheel has a circular shape on the inner peripheral edge facing the stator around the rotation center of the flywheel. A recess is formed, and the rotor magnets and reinforcing members for the magnets are housed in the recess, which simplifies assembly work, shortens the rotation axis, facilitates adjustment of rotational balance, and By preventing the outer ring from elongating due to centrifugal force, it is possible to increase the rotation speed of the flywheel.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a flywheel type energy storage device according to the present invention, FIG. 2a is a vertical sectional view showing a conventional flywheel type energy storage device, and FIG. 2b is a vertical sectional view showing the - A cross-sectional view taken along the X-ray. 1 is a rotating shaft, 4 is a flywheel, 4a is a recess, 5 is a generator motor, 6 is a rotor, 7 is a stator,
8 is a magnet, and 10 is a rotor core. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A flywheel-type energy storage device comprising a rotating shaft equipped with a flywheel, a rotor of a generator motor that rotates integrally with the rotating shaft, and a stator of the generator motor disposed opposite to the rotor. In the device, the flywheel is made of a magnetic material and serves as the rotor core of the rotor, and a circular recess is formed on the inner peripheral edge facing the stator around the rotation center of the flywheel. death,
A flywheel type energy storage device characterized in that a rotor magnet and a reinforcing member for the magnet are housed in the recess.