JPS5969522A - Magnetic bearing device - Google Patents

Abstract

PURPOSE:To dispense with an independent motor for turning a body of rotation, by applying each exciting coil of a three-phase induction motor and a radial magnetic bearing to a yoke to be installed in a housing case supporting rotatably the body of rotation by means of the magnetic bearing. CONSTITUTION:In time of magnetically bearing a body of rotation 1 provided with a rotor 3 opposite to an exciting coil 4 of an axial magnetic bearing installed in the upper center inside a housing case 16, each of radial magnetic bearing-motor combined rotors 6 and 7 are secured to both parts, top and bottom, of the body of rotation 1. And, corresponding to these rotors 6 and 7, yokes 8 and 12 are secured to the inner surface of the housing case 16, and exciting coils 10, 11 and 14, 15 in two rows are attached to each of yokes 8 and 12 respectively. Likewise, each of position detectors 9 and 13 for a lower radial magnetic bearing is installed in the upper and lower parts of these rotors 6 and 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bearing device used in ultra-high-speed rotating machines and the like, and relates to a method of omitting an electric motor for rotating a rotating body.

Figure 1 is a block diagram of a general rotary machine using magnetic bearings. In the figure, 1 is the rotating body, 2, 3° 4.5 is the yoke of the axial magnetic bearing, the rotary element, excitation coil,
Position detector, 6, 7, 8° 9 are the yoke of the lower radial magnetic bearing, rotor, exciting coil, position detector, 1
1, 12, and 13 are the yoke, rotor, and excitation coil of the electric motor, respectively; 141, 15, 16, and 17 are the yoke, rotor, excitation coil, and position detector of the lower radial magnetic bearing; and 18 is the housing case. It is.

Magnetic bearings, which support a rotating body using magnetic force, have many parts such as position detectors and electromagnets, and the axial length of the rotating body is usually longer than mechanical bearings. An increase in the number of parts leads to lower costs, and an increase in the axial length of the rotating body leads to an increase in the size of the equipment, and the resonance point of the shaft is lowered, making it difficult to rotate at ultra-high speeds.

The present invention eliminates these drawbacks, and by omitting the electric motor, reduces the number of parts and reduces the cost of magnetic bearings.Also, the axial length of the rotating body is made equal to that of mechanical bearings, resulting in smaller equipment. And by raising the resonance point of the shaft, ultra-high speed rotation is possible.

FIG. 2 is a configuration diagram of an embodiment of the present invention. In the figure, 1 is a rotating body, 2, 3, 4, and 5 are the yoke, rotor, excitation coil, and position detection of an axial magnetic bearing, respectively. vessel, 6
is an upper radial magnetic bearing and a rotor that also serves as an electric motor; 7 is a lower radial magnetic bearing and a rotor that also serves as an electric motor; 8 is an upper radial magnetic bearing; 9 and 10 are position detectors for the upper radial magnetic bearing; Excitation coil, 1
1 is the excitation coil of the upper motor, 12 is the lower radial magnetic bearing, a yoke that also serves as the motor, 13 and 14 are the position detectors and excitation coils of the lower radial magnetic bearing, respectively, 15 is the excitation coil of the lower motor, and 16 is the housing case. It is. Figure 3 shows 8, 10, 11 and 12 in Figure 2,
14 and 15, and shows a method in which the excitation coil of the radial electromagnet and the excitation coil of the motor are wound around the yoke of No. 17, with the minimum number of slots. In Fig. 3, 1a to 12α are toothed parts of the yoke, 1b to 12
b is the slot portion of the yoke, IC-12c is the excitation coil of the motor, and IJ~12d is the excitation coil of the magnetic bearing.

The motors used in ultra-high-speed rotating machines are generally squirrel-cage, high-frequency, three-phase induction motors. In order to increase the number of rotations, the minimum number of poles is 2, and the total number of slots in the yoke is usually an integral multiple of 3 times the number of poles. The electromagnet of the radial magnetic bearing is Z+#Ze 'i/ 10m! The number of teeth of the yoke must be such that the suction force cannot be generated in four directions, and the direction in which each suction force is generated is 9 degrees. In order for one yoke to function as both a radial electromagnet and a two-pole three-phase induction motor, these two conditions must be met. Therefore, as shown in Figure 3, ld.

2d, 3d to the excitation coil in the V direction, 4d, 5d,
6d is the excitation coil in the X direction, 7d, 8d, and 9d are 1
10d and 11d for one-way excitation coil.

12 If d is made into 2 one-way excitation coils, then 1α, 2α
, 3a in the V direction, 4a, 5a, 6α in the X direction, 7α, 8α, 9α in the V direction, 1ocL, llα, +2cL in the X direction. A radial electromagnet is created in which four attraction forces are generated in each of the n directions and are spaced at n intervals of 90°, 1c, 7c, 4c, 1
06'fru phase, 2c, 8c, 5c, 11 c f
If three-phase windings of v-phase, 3c, 9c, 6c, and 12ckw phases are provided, a three-phase induction motor with two poles and two slots per phase for each pole and a single layer winding can be constructed with a total number of slots of 12. Hereinafter, a device configured in this manner will be referred to as a dual-purpose electromagnet.

By arranging two pairs of these dual-purpose electromagnets, upper and lower, as shown in FIG. 2, a magnetically supported ultra-high-speed rotating machine can be realized without the use of an electric motor. There is a danger that the rotational torque of this dual-purpose electromagnet will be reduced compared to when the electric motor and radial magnetic bearing are separated as shown in Fig. 1, but as shown in Fig.
By arranging a set of dual-purpose electromagnets, it is possible to obtain a sufficient rotational torque greater than that in the case of separate electromagnets as shown in FIG. Furthermore, it is common for high-frequency induction motors to have a silicon steel plate on the outside of the squirrel-cage rotor terminal bar. Therefore, if this magnet is used as the rotor of the dual-purpose electromagnet of the present invention, rotational torque and attractive force can be obtained at the same time.

As is clear from the above description, the present invention allows a magnetic bearing device to be configured without an electric motor, compared to conventional systems.
This can significantly reduce costs, make the axial length of the rotating body the same as that of a mechanical bearing, make the equipment more compact, and raise the resonance point of the shaft, making it possible to rotate at an ultra-high speed of 5 rotations. Although this embodiment describes a magnetic bearing that controls five axes, it goes without saying that it can also be applied to other magnetic bearings that control degrees of freedom in two or more axes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a general power rotating machine using magnetic bearings, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a top sectional view of a dual-purpose electromagnet of the present invention. In Fig. 1, 1 is a rotating body, 2, 3, and 4.5 are the yoke of an axial magnetic bearing, a rotor, an exciting coil,
Position detectors 6, 7, and 8.9 respectively represent the yoke of the upper radial magnetic bearing, the rotor, the excitation coil, and the position detector 1.
1, 12, and 13 are the motive yoke and rotor, respectively.
Excitation coils 14, 15, 16, and 17 are the yoke, rotor, excitation coil, and position detector of the lower radial magnetic bearing, respectively, and 18 is a housing case. In FIG. 2, 1 is a rotating body, 2.3, 4.5 are the yoke of an axial magnetic bearing, a rotor, an excitation coil, a position detector, and 6.
86- Rotor and yoke of electromagnet that also serves as the armrest, 9.10
Position detector and excitation coil for the upper radial magnetic bearing, 11 is the excitation coil for the upper motor, 7.12 is the
13 and 14 are a position detector and an excitation coil for the lower radial magnetic bearing; 15 is an excitation coil for the lower motor; and 16 is a housing case. In Fig. 3, 1a to 12α are tooth parts of the yoke, 1b to 12b are slot parts of the yoke, ld, 2d, and 3d are excitation coils in the V direction of the magnetic bearing, and 4d, 5d, and 6d are the magnetic bearings. excitation coils in the
．． 10C is a U-phase, 2C28C15C11C is a τ phase, and 3C29C, 6C, and 12C are W-phase symmetrical three-phase windings of a three-phase induction motor. Applicant Daini Seikosha Co., Ltd. Agent Patent Attorney Mogami 7-

Claims (1)

[Claims] In magnetic bearings used in ultra-high-speed rotating machines, etc., by applying the excitation coil of a three-phase induction motor and the excitation coil of a radial magnetic bearing to one yoke, it can be used as both a three-phase induction motor and a radial magnetic bearing. Features magnetic bearing device.