JPS648223B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flywheel type energy storage device that stores electrical energy as rotational inertia energy of a flywheel and releases the energy as necessary, and particularly relates to a bearing portion that pivotally supports a rotating body. Regarding the improvement of

In general, in this type of device, the means to improve the energy storage capacity are to increase the moment of inertia around the rotation axis of the flywheel,
Alternatively, countermeasures such as increasing the operating angular velocity of the flywheel are being taken to realize devices with high energy density, or to utilize rotational inertia energy as effectively as possible to increase the conversion efficiency of the device. The device has a vertical rotating machine structure. In addition, most of the weight of the rotating body is absorbed by, for example, an electromagnet or a permanent magnet, thereby reducing the thrust load on the lower bearing and reducing energy loss due to frictional torque in the lower bearing. Further, as the lower bearing, it is customary to use a pivot bearing or the like due to problems such as bearing life and bearing loss at high speed rotation.

FIG. 1 shows a conventional device of this kind. In the figure, 1 is a flywheel, and 2 is a flat generator motor. It is configured.
Reference numeral 5 denotes a pivot bearing, which is composed of a rotating side pivot shaft 6, a stationary side pivot bearing 7, and a damper 8 that supports the pivot bearing 7. The damper 8 is filled with oil having a high viscosity coefficient. Reference numeral 9 denotes a magnetic bearing, for example, a rotation side magnetic bearing 10 having a permanent magnet on its circumference.
and a stationary side magnetic bearing 11 having, for example, a permanent magnet on its circumference.The rotating side magnetic bearing 10 is attached to a holding frame 12, and the stationary side magnetic bearing 11 is attached to an upper bracket 13, respectively. 1
4 is a side bracket, 15 is a pedestal, and pedestal 1
A stator 4 of the generator motor 2 is mounted on the generator motor 5. Reference numeral 16 denotes a lower bracket, and 17 denotes a storage chamber in a sealed casing consisting of an upper bracket 13, a side bracket 14, a pedestal 15, and a lower bracket 16. Inside this storage chamber 17, the above-mentioned components and other devices are configured. Element parts are stored in this storage chamber 17, and the interior of this storage chamber 17 is kept in a vacuum during normal use.
Further, the flywheel 1, rotor 3, pivot shaft 6, and holding frame 12, which constitute the rotating body, are integrally connected by, for example, bolts or the like.

In the above configuration, energy is stored by rotating the flywheel 1 with the generator motor 2 and exchanging it as rotational inertia energy of the flywheel 1. During normal operation, most of the weight of the rotating body (mainly the flywheel 1) is absorbed by the magnetic bearing 9 in order to reduce the thrust load applied to the pivot bearing 5 and reduce friction loss. The magnetic bearing 9 also functions as a non-contact bearing for stably rotating the rotating body. Further, the attraction force can be adjusted by, for example, changing the gap h between the rotating magnetic bearing 10 and the stationary magnetic bearing 11, or by changing the type, shape, etc. of the magnets of the rotating magnetic bearing 10 and the stationary magnetic bearing 11, for example. This can be easily done by appropriately changing the dimensions and the like.

However, in conventional flywheel-type energy storage devices, the radial rigidity of the magnetic bearing is relatively low, so if the flywheel has a large eccentric center of gravity, the vibration amplitude can become extremely large at dangerous speeds. A significant increase in vibration may occur due to external disturbances. In such a case, contact occurs between the rotating body and the magnetic bearing, resulting in damage or breakage to the device, resulting in deficiencies in terms of safety and reliability.

The present invention has been made to eliminate the drawbacks of such conventional devices, and includes a rotary shaft having a flywheel and rotatably placed upright in a sealed housing, and a rotor that rotates integrally with the rotary shaft. a generator motor installed in the casing, a pivot bearing supporting the lower end of the rotating shaft, and a pair of magnets arranged opposite to each other between the upper part of the rotating body and the top wall of the casing. a magnetic bearing device that pivotally supports the upper part of the rotating body in a non-contact state, and an emergency bearing device that is arranged at the upper end of the rotating shaft of the casing with a required gap between it and the outer periphery of the rotating shaft. It is an object of the present invention to provide a flywheel type energy storage device that can quickly reduce the increase in vibration of a rotating body caused by low radial rigidity of a magnetic bearing and restore performance.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 2 is a longitudinal sectional view showing an embodiment of the flywheel type energy storage device according to the present invention. A rolling bearing 19 is arranged on the outer circumference of the upper bracket 13 with a required gap around the shaft, and this rolling bearing 19 is supported by a stepped hole in the upper bracket 13. In addition, this stepped hole is closed by a lid body 20, and the storage chamber 1
The sealed state of 7 is ensured. FIG. 3 is a partial cross-sectional view showing another embodiment. In this case, the inner peripheral surface of the rolling bearing 19 has a cylindrical shape made of a low-friction material such as fluororesin or an oil-impregnated sintered alloy. A protective ring 21 is attached.

With the above configuration, even if the vibration amplitude of the flywheel 1 increases due to the eccentric center of gravity of the flywheel 1, the electromagnetic attraction force of the generator motor 2, or other disturbances, the shaft 18 and the rolling bearing 1
9 is smoothly supported by the relative rotation of the rolling bearing 19, and vibration increase is quickly reduced. Further, by disposing a low-friction protection ring 21 on the inner circumferential surface of the rolling bearing 19, the contact condition can be improved.

In the embodiment described above, the protective ring 21 is attached to the rolling bearing 19, but it may be attached to the shaft 18 or both.

As described above, the present invention provides a power generation system that includes a rotating shaft that has a flywheel and is rotatably placed upright within a sealed housing, and a rotor that rotates integrally with the rotating shaft, and that is installed within the housing. An electric motor, a pivot bearing that supports the lower end of the rotating shaft, and a pair of magnets that are arranged opposite to each other between the upper part of the rotating body and the top wall of the casing, and the upper part of the rotating body is in a non-contact state. The structure includes a magnetic bearing device that is pivotally supported at Increased vibration of the rotating body due to the electromagnetic attraction force of the housed generator motor and the low radial rigidity of the magnetic bearing is quickly reduced, greatly improving vibration safety and reliability during high-speed rotation. The effect is that it can be improved.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a conventional flywheel energy storage device, FIG. 2 is a vertical cross-sectional view showing an embodiment of the present invention, and FIG. 3 is a portion showing another embodiment of the present invention. It is an enlarged sectional view. [1: flywheel, 3: rotor, 6: pivot shaft, 12: holding frame] (rotating body), 2: flat generator motor, 5: pivot bearing, 9: magnetic bearing, [13: upper bracket, 14 : Side bracket, 15: Pedestal, 16: Lower bracket, 20: Lid (sealed housing), 18: Shaft (upper end of rotating shaft), 1
9: Rolling bearing (emergency bearing device) 21: Protective ring (low friction material). Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A generator-motor having a flywheel and a rotary shaft rotatably placed upright within a sealed casing, and a rotor that rotates integrally with the rotary shaft and installed within the casing. and a pivot bearing that supports the lower end of the rotating shaft, and a pair of magnets that are arranged opposite to each other between the upper part of the rotating body and the top wall of the casing, and the upper part of the rotating body is held in a non-contact state. A magnetic bearing device that supports the shaft,
and a flywheel type energy storage device comprising: an emergency bearing device disposed at an upper end portion of the rotating shaft of the housing with a required gap maintained between the outer circumference of the rotating shaft and the outer periphery of the rotating shaft. 2. The flywheel energy storage device according to claim 1, wherein a rolling bearing is used as the emergency bearing device. 3. The flywheel type energy storage device according to claim 2, characterized in that a low-friction material is disposed on at least one of the mutual contact surfaces between the rolling bearing and the shaft.