JPS6311857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating electric machine, and particularly to a damping mechanism thereof, and for example, when a momentum wheel supported by a magnetic bearing, which performs attitude control of a space satellite, passes a critical speed, the shaft vibration is easily damped. Relating to those attempting to pass dangerous speeds.

The following explanation will be given using a rotating electric machine for space satellite attitude control as an example.

FIG. 1 is a sectional view showing this type of conventional rotating electric machine, in which 1 is a shaft, 2 is an upper flange, 3a is a first bearing exclusively for damping, and 3b is a second bearing exclusively for damping 4.
is the rotor, 5a is the first magnetic bearing on the stator side, 5b
is a stator side second magnetic bearing, 6 is a bearing control coil, 7 is a rotor magnetic pole, 8a is a stator side third magnetic bearing, 8b is a stator side fourth magnetic bearing, 9 is a permanent magnet, 10 and 11 are spacers, and 12 is a 3rd bearing dedicated to damping, 13 is 4th bearing dedicated to damping,
14 is a lower flange, 15 is a base body, and 16 is a brushless motor.

One end of the shaft 1 is fixed to the base 15 side,
The other end is open to the base. The bearing control coil 6 is a coil that controls the stator side first to fourth magnetic bearings 5a, 5b, 8a, 8b relative to the rotor magnetic poles 7. The configuration of the one in FIG.
3, and second and third bearings 3 exclusively for damping.
b, 12 rotate simultaneously with the rotor 4. The rotor 4 is rotated by a brushless motor in a non-contact manner. The first and second bearings 3a and 3b dedicated to damping and the third and fourth bearings dedicated to damping
The bearings 12 and 13 are used to strengthen the radial centering force between them and to pass critical speeds.

Flywheels that are supported by magnetic bearings and have active bearings in the axial direction have weak radial damping, so in the process of increasing the rotation speed, the critical speed of conical vibration and cylindrical vibration is reduced. In order to pass, it is necessary to increase the damping force.

Since the conventional damping mechanism is configured as described above, the second and third damping bearings 3b and 12 fixed to the rotor 4 side must rotate simultaneously with the rotor 4, and at high speed rotation. Consideration of strength becomes an issue. In addition, the first and second bearings 3a and 3b for damping, the third bearing for damping,
Strict dimensional accuracy is required for the distance and radial concentricity of each of the fourth bearings 12 and 13 to exhibit a damping effect. Further disadvantages include high cost, difficult maintenance, complex structure, constant operation even when damping is not required, and slight loss of magnetic bearings. This invention was made in order to eliminate the drawbacks of the conventional ones as described above.
By removing the fourth bearings 3a, 3b, 12, and 13 and replacing them with a damping conductor (for example, a copper plate) and a damping electromagnet, it can be used as a damper only when the rotation speed requires damping. It is an object of the present invention to provide a device that can be easily set with dimensional accuracy, has a simple structure, and does not require damping parts to rotate simultaneously with the rotor.

A rotating electric machine according to an embodiment of the present invention will be explained with reference to the drawings. Figure 2 shows its cross-sectional view, where 1 is the axis;
One end is supported by the base 15, and the other end is an open end. 2 is a coil core, 3 is a coil, and 2 and 3 constitute a magnet. 4 is a rotor, 5a is a first magnetic bearing on the stator side, 5b is a second magnetic bearing on the stator side, 6
is a shaft control coil, 7 is a rotor magnetic pole, 8a is a third magnetic bearing on the stator side, 8b is a fourth magnetic bearing on the stator side, 9 is a permanent magnet, 10 is a spacer 11 is also a spacer, 12 is a damping conductor; It is a copper plate. 13 is a coil support arm, 14 is a mounting flange 15 is a base body, and here it is a base plate. 16 is a brushless motor, and 20 is a stator.

In this invention, the electromagnets 2 and 3 are attached to the coil support arm 13 attached to the base body 15 (a plurality of electromagnets may be provided in the circumferential direction), and the conductor 12 is attached to the shaft 1, so that the damper effect due to the deflection of this shaft , and between the conductor 12 and the electromagnets 2 and 3, the necessary current is passed through the coil 3 at a critical speed, and the core 2 and the conductor 12 are
The eddy current effect generated during this process forces the copper plate to exert a damping effect. Therefore, unlike the conventional structure, there is no need to constantly act on the damper, there is no need for parts dedicated to damping to rotate with the rotor, the structure is simple, and there is no need to improve the dimensional accuracy of the parts.

As explained above, the present invention provides a shaft whose one end is supported by a base body and whose other end is an open end, a stator fixed to this shaft, a rotor that rotates around this stator, and a rotor fixed to the other end of the shaft. Since the damping conductor and the damping electromagnet facing the conductor and supported on the base body side are provided, the damping conductor and the damping electromagnet are not on the rotor side, and therefore, as shown in FIG. The structure is simpler than that of the conventional example, and the dimensional accuracy of parts can be reduced. Also, by controlling the electromagnet current, there is no need to constantly apply a damper.
It is also possible to provide a damper effect only when necessary.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional rotating electric machine, and FIG. 2 is a sectional view of a rotating electric machine according to an embodiment of the present invention. In the figure, 1 is a shaft, 2 is a coil core, 3 is a coil, and 2 and 3 constitute an electromagnet. 4 is the rotor, 5
a, 5b, 8a, 8b are stator side first to fourth magnetic bearings, 7 is a rotor magnetic pole, 12 is a damping conductor, 13 is a coil support arm 15 is a base body, 20
is the stator.

Claims (1)

[Claims] 1. A shaft whose one end is supported by a base and whose other end is an open end, a stator fixed to this shaft, a rotor rotating around this stator, and a damping device fixed to the other end of the shaft. A rotating electric machine comprising a damping electromagnet that faces the conductor and is supported on the base body side. 2. The rotating electric machine according to claim 1, wherein the rotor is supported by the stator via a magnetic bearing.