JPH0215728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a bearing support mechanism for a vertical high-speed rotating body.

FIG. 1 shows an overview of a conventional power storage flywheel device. In the figure, 1 is a flywheel, 2 is a generator/electric motor, 3 is an upper bearing, 4 is a lower bearing, 5 is an emergency thrust bearing, 6 is an upper seal, 7 is a lower seal, 8 is a casing, 9 is a vacuum pump, 10 is an oil tank, 11 is a lubricating oil pump,
12 is a magnetic bearing.

When storing electric power in the flywheel 1, the generator/motor 2 is operated as an electric motor to increase the rotational speed of the flywheel 1 and store it as rotational energy. Conversely, when generating electricity, flywheel 1
The generator/motor 2 driven by the motor 2 acts as a generator and converts the rotational energy of the flywheel 1 into electric power. In this way, the energy storage flywheel device is operated over a very wide rotational speed range. To reduce energy loss during storage, (a)
Most of the weight of the flywheel is supported by the magnetic bearing 12, reducing energy loss in the bearings 3 and 4, and (b) windage loss of the flywheel 1 is reduced by creating a vacuum inside the casing 8 with the vacuum pump 9. I'm letting you do it.

Since the maximum rotational speed of the current flywheel is low, it is possible to avoid dangerous speeds by making the lowest order natural frequency higher than the maximum rotational speed. but,
Current flywheels are heavy compared to the amount of energy they store, so to increase the amount of energy stored,
Increasing the rotation speed has a great effect. On the other hand, if the operating speed is increased, the critical speed will be within the normal operating range.

An object of the present invention is to focus on the above points and provide a bearing support mechanism for a vertical high-speed rotating body, which is characterized in that a rolling bearing is interposed between the rotating shaft and the bearing housing. , a bearing holding member is brought into contact with the lower end of the rolling bearing, and a plurality of mounting bolts reduce the rigidity of the bearing holding member in a direction perpendicular to the rotating shaft, so that the dead weight applied to the rotating shaft is absorbed by the bearing and the bearing holding member. is attached to the casing so that a tensile force is applied to the bolt through the bolt, and a damper cylinder is fitted to form a minute annular gap between the cylindrical part forming the outer periphery of the bearing holding part and the casing, respectively. This is done by filling the annular gap between the two inserts with oil.

That is, by elastically supporting the bearing, the lowest natural frequency is lowered to below the normal operating range, and the second natural frequency is above the normal operating range,
This is to ensure that there are no critical speeds within the normal operating range, and in this case, a compact and highly effective damper cylinder is installed to completely pass through the lowered lowest natural frequency.

This makes it possible to realize a power storage flywheel that eliminates dangerous speeds within the normal operating range, enables safe operation, and stores a large amount of energy relative to its weight.

The present invention is applicable to power storage flywheels and high-speed rotating machines.

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

FIG. 2 is an explanatory diagram showing a high-speed rotating power storage flywheel device according to one embodiment of the present invention. In the figure, 1' is a truncated disk type flywheel, 3 is an upper bearing, 14 is an upper support spring, and 16
1 is an upper damper, 4 is a lower bearing, 15 is a lower support spring, 17 is a lower damper, and 13 is an electromagnetic clutch. The upper bearing 3 and the lower bearing 4 are connected to the upper support spring 1.
4. It is attached to the casing 8 with a lower support spring 15. An electromagnetic clutch 13 connects the generator/motor 2 and the flywheel 1'.

FIG. 3 is a sectional view showing an embodiment of the bearing support structure according to the present invention, which is a specific structure of the upper bearing 3, the upper support spring 14, and the upper damper 16, and the right half a of the figure shows the first embodiment. show.

In Fig. 3a, 20 is a flywheel shaft;
23 is a bearing support sleeve, 21 and 22 are sleeve fixing nuts, 25 is a bearing holding member, 24 is a bearing housing, 26 is a damper cylinder, 28 is a support bolt, 27 is a support bolt mounting flange, 29 is an O-ring for the damper It is. The support bolt 28 has an hourglass shape. In the same figure, the flywheel weight W
It has a structure that can support the support bolt 28.
A tensile force is applied to the . In addition,
101 is an oil supply hole where oil flows in as shown by arrow a.
02 is an oil drain hole, and oil is drained in the direction indicated by arrow b. 1
03 is a damper cylinder oil supply hole, and 104 is a damper cylinder oil drain hole.

The operation in the case of the above configuration will be described.

In the high-speed rotating flywheel shown in FIG. 2, improvements over the conventional flywheel shown in FIG. 1 are shown below.

(a) The power loss of the vacuum seal increases rapidly at high speed rotation, so it is provided only at the top.
Additionally, since the structure is such that a seal is provided only at the top, the degree of vacuum increases and windage loss decreases. If the inside of the generator/motor 2 is also kept in a vacuum, the upper seal 6 can also be omitted.

(b) By separating the flywheel 1', which is a rotor, from the generator/motor when the electromagnetic clutch 13 is not in the power storage or power generation state,
Measures to reduce power loss when left unused.

(c) By making the rotor a truncated disk-shaped flywheel 1', the stress distribution is made uniform, and the storage energy per unit weight is increased, while being sufficiently safe against the centrifugal force generated by high rotation. There is.

If the support structure of the bearings 3 and 4 is not made into a rigid support structure, deformation will occur and the durability will be significantly reduced. In addition, when using a rigid support structure, there is no problem in the case of a conventional structure with a low rotational speed because the natural frequency is above the normal operating range. However, in a flywheel rotating at high speed, the lowest natural frequency is within the normal operating range.

Therefore, by holding the bearing rigidly and supporting the entire bearing with several support bolts 28, the spring constant in the horizontal direction is made constant in the circumferential direction, and the spring constant is reduced.
The lowest natural frequency was set below the normal rotation speed. At this time, since the flywheel 1' has a truncated disk shape and the overall weight is small, the secondary natural frequency is sufficiently higher than the normal rotation speed.

The support bolt 28 is used under tension and there is no concern about buckling, so it can be made sufficiently thin. Further, by making the support bolt 28 into a drum shape, the stress is made uniform and the spring constant is made small.

In the operating state, since it is supported by the magnetic bearing 12, even if the natural frequency is set below the normal rotation speed,
The amplitude increases during the rise to the normal rotation speed.
Therefore, it is necessary to use a damper, but conventional dampers have large dimensions and, moreover, do not provide a uniform damping coefficient in the horizontal direction.

In FIG. 3a, the rolling bearing 3 is held by bolting the bearing housing 24 and the bearing holding member 25, and the rolling bearing 3 is held by the bearing holding member 25.
By attaching to the support bolt attachment flange 27 at position 5 via several support bolts 28 and bolting the support bolt attachment flange 27 to the casing 8, the support rigidity in the horizontal direction is uniformly reduced.

Further, the cylindrical portion 10 of the outer peripheral portion of the bearing holding member 25
5, the damper cylinder 26, and the casing 8, minute annular gaps 106 and 107 are formed, and this gap 1
By filling the holes 06 and 107 with oil, a uniform damping coefficient can be obtained in the horizontal direction. The temperature of the oil in this gap changes as the operating time increases,
Since the damping effect changes, the oil supply hole 101,
103, oil drain holes 102 and 104 are used to constantly replace the oil to prevent changes.

By using the bearing support mechanism shown in Figure 3a, the same low spring constant is given in all horizontal directions,
Moreover, it is possible to give the same damping coefficient in all directions.

The above case has the following effects.

In a vertical high-speed rotating body, the bearing is held by a rigid structure, the holding structure is further attached to the casing with bolts, and there is a gap between the holding structure, that is, the cylindrical part of the outer circumference of the bearing holding member, and the casing. A flywheel for high-speed rotation can be realized by a bearing support mechanism in which damper cylinders each forming an annular gap are inserted and both annular gaps are filled with oil.

The left half b of FIG. 3 is a sectional view showing a second embodiment of the bearing support mechanism according to the present invention.

In the figure, 30 is a tapered support bolt, 31
3 is a ball support bearing, and 32 is a ball bearing retainer.

In this case, by supporting pins at the support bolt mounting flange, a spring constant lower than that shown in FIG. 3a can be obtained.

The effect is the same as the first embodiment of FIG. 3a.

The right half a of FIG. 4 is a sectional view showing a third embodiment of the bearing support mechanism according to the present invention.

In the figure, 40 is a cylindrical shell with an opening for supporting the bearing, 43 is an opening, and 41 and 42 are mounting bolts.

The operation and effect in this case are the same as in the first embodiment.

The left half b of FIG. 4 is a sectional view showing a fourth embodiment of the bearing support mechanism according to the present invention.

In the figure, the bearing holding member 25 is replaced by a bearing supporting cylindrical shell 50, a bearing supporting plate 53, a mounting flange 52, and a mounting bolt 51.

The operation and effect in this case are the same as in the first embodiment.

Although only the bearings that support the weight of the flywheel have been described in Figure 3 a, b and Figure 4 a, b, the bearings that do not support the weight of the flywheel can be considered using the same concept. So,
Omitted.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing a conventional power storage flywheel device, FIG. 2 is an explanatory view showing an example of a power storage flywheel device according to the present invention, and FIG. 3a is an explanatory view showing a first embodiment of the power storage flywheel device according to the present invention. FIG. 3b is a cross-sectional view showing a bearing support mechanism according to a second embodiment of the present invention, and FIG. 4a is a cross-sectional view showing a bearing support mechanism according to a third embodiment of the present invention. FIG. 4B is a sectional view showing a fourth embodiment of the bearing support mechanism according to the present invention. 3...Bearing, 8...Casing, 20...Flywheel shaft, 24...Bearing housing, 25...
... Bearing holding member, 26 ... Damper cylinder, 27 ... Support bolt mounting flange, 28 ... Support bolt, 1
05... Cylindrical part.

Claims (1)

[Scope of Claims] 1. In a bearing support mechanism for a vertical high-speed rotating body, a rolling bearing is interposed between the rotating shaft and the bearing housing, a bearing holding member is brought into contact with the lower end of the rolling bearing, and the bearing The holding member is attached to the casing so that its own weight applied to the rotating shaft by a plurality of mounting bolts with reduced rigidity in a direction perpendicular to the rotating shaft is applied as a tensile force to the bolts via the bearing and the bearing holding member. Attachment, further inserting damper cylinders forming minute annular gaps between the cylindrical part forming the outer periphery of the bearing holding member and the casing, respectively,
A bearing support mechanism for a vertical high-speed rotating body characterized by filling oil between the two annular bodies.