JP2000188848A - Dynamo-electric machine functioning as bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamo-electric machine which functions also as a bearing with stable operation and without causing unexpected fluctuation in rotating torque or in radial direction of a rotor. SOLUTION: A plurality of stator coils u1 to u3, v1 to v3, and w1 to w3 of the identical phase are provided in a circumferential direction of a stator 1, and stator coils u1 to w1, u2 to w3, and u3 to w3 of different phases to each other are connected at an end thereof to form a plurality of group coils 3A to 3C. In addition, each non-magnetic plate is inserted between the magnetic poles 3A to 3C to form a magnetic separation part 1 between the magnetic poles 3A to 3C as adjoining group coils and obtain magnetic resistance is obtained which is larger than the magnetic resistance between the stator blocks 11 to 13, on which each group coil is mounted, and a rotor 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine which also rotates a rotor while positioning a rotor in a radial direction by an electromagnetic field of a stator coil, and more particularly to a structure improvement for eliminating unstable operation thereof.

[0002]

2. Description of the Related Art Instead of a mechanical bearing using a bearing or the like, a magnetic bearing that supports a rotor in a non-contact manner by the electromagnetic force of a stator coil is known. Further, a rotating magnetic field is formed by the stator coil. A bearing / rotary electric machine has also been proposed which also applies a rotational force to the rotor. For example, in the bearing-rotating electric machine described in Japanese Patent Application Laid-Open No. 7-255147, an exciting current having a phase shifted is supplied to each stator coil to form a rotating magnetic field, thereby rotating the rotor and controlling the amplitude of the exciting current. To position the rotor in the radial direction.

[0003]

In the above-mentioned conventional bearing / rotary electric machine, during use, the rotational torque of the rotor and the radial position of the rotor often fluctuate unexpectedly, resulting in unstable operation. There was something.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a bearing-operated rotary electric machine in which the rotational torque and the radial position of the rotor do not change unexpectedly and are stable in operation. I do.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a bearing / rotating electric machine in which a rotor is rotated while being positioned in a radial direction by an electromagnetic field of a stator coil. A magnetic isolation portion having a magnetic resistance larger than the magnetic resistance between the stator and the rotor of each stator coil installation portion is provided between the magnetic poles of adjacent stator coils.

In the first aspect of the present invention, by providing the magnetic isolation portion, the status coils forming the magnetic path necessary for generating the translational force in the adjacent stator coils are set as one set, and the gap between each set is magnetically set. The magnetic flux generated in each set of stator coils is isolated, and thus forms a closed magnetic path reciprocating with the rotor without interfering with the magnetic flux generated in the other set of stator coils. As a result, unexpected fluctuations in the rotational torque and the radial position of the rotor are prevented, and the operation of the rotating electric machine is stabilized.

According to a second aspect of the present invention, in a bearing-rotating electric machine that rotates while positioning a rotor in a radial direction by an electromagnetic field of a stator coil, a plurality of stator coils having the same phase are arranged in the circumferential direction of the stator, A stator coil is connected at one end to form a plurality of sets of coils, and each of the sets of coils is connected to an exciting current source, and the sum of currents at the connection points of the stator coils constituting the set coil is connected by these exciting current sources. The positioning excitation current and the rotation excitation current are superimposed so as to be zero and supplied to each set coil, and the magnetic force between the stator and the rotor of each set coil installation part is provided between adjacent set coils. A magnetic isolation unit having a magnetic resistance greater than the resistance is provided.

In the second invention, in addition to the operation and effect obtained in the first invention, the positioning excitation current and the rotation excitation are set so that the total current at the connection points of the stator coils constituting the assembled coil becomes zero. Since the current is superimposed and supplied,
An excitation current source may be provided for each coil group, and it is not necessary to provide an excitation current source individually for each stator coil as in the conventional case. Therefore, the size of the power supply device can be reduced, and the outer shape and weight of the entire rotating electric machine can be reduced. In addition, since the positioning excitation current and the rotation excitation current are superimposed and supplied to each set coil, the positioning control and the rotation control of the rotor can be performed separately and independently, and the control system design becomes easy. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 schematically shows a main part of a rotating electric machine which also serves as a bearing. A ring-shaped rotor 2 is disposed around a center annular stator 1. A conductor is embedded in the rotor 2 to form an induction type rotating electric machine. The stator 1 is actually separated at three locations in the circumferential direction into stator blocks 11 to 13, and non-magnetic plates of a predetermined thickness having a large magnetic resistance are interposed between the adjacent stator blocks 11 to 13. The magnetic isolation parts 14 to 16 are provided. This magnetic isolation part 14-
16, the adjacent stator blocks 11 to 13
The magnetic resistance between them is larger than the magnetic resistance between stator blocks 11 to 13 and rotor 2. The stator coils u1, u2, u3, v1, v2, v3, w1, w2,
w3 is provided with three phases of U-phase, V-phase and W-phase, and wound in slots (not shown) on the outer periphery of the stator blocks 11 to 13 as described later, and stator coils u1 to u3, v of the same phase are wound.
1 to v3 and w1 to w3 are provided at three positions at equal intervals in the circumferential direction of the stator 1.

FIGS. 2 and 3 show the stator coils u1, v1.
, W1. In FIG. 2, a circle indicates the stator coil u1, a square indicates the stator coil v1, and a diamond indicates the stator coil w1, white indicates the start of coil winding, and black indicates the end of coil winding. In addition, numerals such as “1” and “2” indicate slot numbers, and lowercase letters attached to the numerals indicate that “a” is located at the top of the slot and “b” is located at the bottom of the slot. Indicates that

For example, the stator coil u1 is provided between the upper part of the eleventh slot and the upper part of the fifth slot, between the twelfth slot and the upper part of the sixth slot, and between the lower part of the first slot and the lower part of the seventh slot. , The winding is wound between the lower stage of the second slot and the lower stage of the eighth slot, respectively, and the winding end and the winding start are connected as shown in FIG.

As apparent from FIG. 2, the stator coil u1 is distributed over a wide range from the first slot to the twelfth slot, while the stator coil v1 is distributed in the third slot.
The stator coil w1 is unevenly distributed in the range from the slot to the twelfth slot and in the range from the first slot to the tenth slot. Such winding is the same for the other stator coils u2 to w2 and u3 to w3, and FIG. 1 schematically shows this state.

FIG. 4 shows a power supply circuit for each of the stator coils u1 to w3. As described above, the stator coils u1 to u of the respective phases provided at three positions at equal intervals in the circumferential direction of the stator 1 are provided.
3, v1 to v3 and w1 to w3 have different phases and are connected to each other at one end to form magnetic poles 3A, 3B, 3 of three sets of coils.
C, and each of the stator coils u1, v1, w1, u2, v2, w2,.
u3, v3, and w3 are three-phase inverters 4A and 4A, respectively.
B, 4C are connected to the output terminals to receive the supply of the exciting current. Each of the three-phase inverters 4A to 4C has a current signal Iu1, Iv1, Iw1, Iu2, Iv2, Iw2, Iu3, Iv3, I3 to be described later.
w3 is input, and the current signals Iu1 to Iw3 are command signals Ru1, Rv1, Rw1, and Ru output from the rotation drive controller 5.
2, Rv2, Rw2, Ru3, Rv3, Rw3 and command signals Fv1, Fw1, Fv2, Fw2,
Fv3 and Fw3 are superimposed as described later.

A feedback signal from a rotation sensor 51 for detecting the rotation angle of the rotor 2 is input to the rotation drive controller 5, and a feedback signal from the rotation sensor 51 and a radius of the rotor 2 are input to a radial attitude controller 6. A feedback signal from the displacement sensor 61 for detecting the position in the direction is input. The output signal lines from the rotation drive controller 5 are actually three each shown in FIG. 4 for outputting the above-mentioned command signals Ru1 to Rw3. The signal lines shown in FIG. 4 for outputting the command signals Fv1 to Fw3 are actually two in each case. Then, these command signals Ru1 to
Rw3, current signals Iu1 to Iv1 generated by superimposing Fv1 to Fw3
Iw3 is sent to the three-phase inverters 4A to 4C by three output signal lines, respectively, where the power is amplified and the respective stator coils u1 to w1, u2 to
Supplied to w2, u3 to w3.

That is, in the rotation drive controller 5, based on the rotor rotation angle θ fed back from the rotation sensor 51, the stator coils u1 to w1,. u2
Command signals Ru1 to Rw3 as shown in the following equations (1) to (9) are issued to .about.w2, u3 to w3.

Ru1 = Io * sin (ωt) (1) Rv1 = Io * sin (ωt + 2π / 3) (2) Rw1 = Io * sin (ωt−2π / 3) (3) Ru2 = Io * sin (Ωt) (4) Rv2 = Io * sin (ωt + 2π / 3) (5) Rw2 = Io * sin (ωt−2π / 3) (6) Ru3 = Io * sin (ωt) (7) Rv3 = Io * sin (ωt + 2π / 3) (8) Rw3 = Io * sin (ωt−2π / 3) (9) where Io is output from the three-phase inverters 4A to 4C to generate a rotating magnetic field. And t is time and ω is angular velocity.

FIGS. 5A to 5C show the above-mentioned command signals R.
The change with time of u1 to Rw3 is shown. The respective stator coils u1 to w1, u2 to w2, u3 to w are based on the command signals Ru1 to Rw1, Ru2 to Rw2, Ru3 to Rw3 which are out of phase by 120 °.
6 to 8 by supplying the rotation exciting current to
A rotating magnetic field that repeats the state shown in (1) at a predetermined cycle is formed, and the rotor 2 is driven to rotate. That is, FIG.
At the time t1 of each stator coil w1
~ W3 forms a large magnetic flux from the stator 1 to the rotor 2. FIG. 7 shows the result at time t2 in FIG. 5, and a large magnetic flux from the stator toward the rotor is formed by each of the stator coils u1 to u3. FIG. 8 shows the result at time t3 in FIG. 5, and a large magnetic flux from the stator 1 to the rotor 2 is formed by each of the stator coils v1 to v3. 6 to 8, the U-phase stator coils u1 to u3 are located at the center, and the V-phase and W-phase stator coils v1 to v3, w
Since 1 to w3 are located eccentrically to the left and right, a smooth rotating magnetic field can be obtained.

The radial attitude controller 6 calculates and outputs command signals Fv1, Fw1, Fv2, Fw2, Fv3, Fw3 as follows. That is, the x-axis is taken in the horizontal direction in the plane perpendicular to the rotor axis, and the y-axis is taken in the vertical direction.
, Ys, the vector current values Ix, Iy in the x-axis direction and the y-axis direction are calculated by the following equations (10), (11).

[0019]

(Equation 1)

Here, KPX, KPY, KiX, KiY, K
DX and KDY are the respective gains of the radial direction PID (proportional-integral-derivative) control, and are functions of the angular velocity ω.

Next, the vector current values Ir1, Ir2, Ir3 to the magnetic poles 3A to 3C of each set coil for realizing the above-mentioned vector current values Ix, Iy are calculated from the phase relationship shown in FIG. To (23).

[0022]

(Equation 2)

The command signals Fv1 to Fw3 are converted to F
v1 = Ir1, Fw1 = -Ir1, Fv2 = Ir2, Fw2 = -Ir2,
Assuming that Fv3 = Ir3 and Fw3 = -Ir3, each stator coil v1
, W1, v2, w2, v3, w3. For example, based on the command signals Fv1, Fw1, each of the stator coils v1, w
1 is supplied with the positioning excitation current,
11, magnetic fluxes in the opposite directions are formed at the portions of the stator coils v1 and w1, and these magnetic fluxes generate an attractive force on the rotor 2, so that the combined attractive force is represented by an arrow in FIG. As shown, it occurs at the center of the stator coil u1. Similarly, the other command signals FV2, FW2, FV3, F
As shown in FIGS. 12 and 13, the W3 generates an attractive force on the rotor 1 at the center of the stator coils u2 and u3, respectively, and these attractive forces are transmitted to the command signals FV1 to FW3.
By performing the adjustment, the attitude of the rotor 2 can be controlled to a predetermined position in the radial direction.

Then, the command signals Ru1 to Rw3 from the rotary drive controller 5 and the command signals FV1 to FV1 to
FW3 is superimposed as in the following equations (24) to (32) and output to the three-phase inverters 4A to 4C as current signals Iu1 to Iw3.

Iu1 = Ru1 ... (24) Iv1 = Rv1 + Fv1 ... (25) Iw1 = Rw1 + Fw1 ... (26) Iu2 = Ru2 ... (27) Iv2 = Rv2 + Fv2 ... (28) Iw2 = Rw2 + Fw2 ... (29) Iu3 = Ru 30) Iv3 = Rv3 + Fv3 (31) Iw3 = Rw3 + Fw3 (32)

As described above, such current signals Iu1 to Iw3 are power-amplified by the three-phase inverters 4A to 4C, and the respective stator coils u1 to w1, u2 to w2,.
It is supplied to u3 to w3 to rotate the rotor 2 while positioning it in the radial direction. In the present embodiment, the stator coils u1 to w1 forming the magnetic poles 3A to 3C of each group coil are used.
, U2 to w2, and u3 to w3, the sum of the exciting currents (for example, Iu1 + Iv1 + Iw1) becomes zero. Therefore, the three-phase inverter 4A is provided for each of the magnetic poles 3A to 3C of the set coil.
4C may be provided, and it is not necessary to provide an exciting current source for each stator coil as in the related art. Also, the command signals Ru1 to Rw3 and the command signals FV1 to
The rotation of the rotor and the positioning in the radial direction can be easily and independently controlled by the FW3.

FIG. 14 shows the magnetic flux formed when the positioning excitation current flows through each of the stator coils v1 to v3 and w1 to w3. 14 and 15, the way of winding the coils is the same as in FIGS. In the present embodiment, as described above, the magnetic isolation portions 14 to 16 having large magnetic resistance are provided between the stator blocks 11 to 13 corresponding to the respective coil groups 3A to 3C.
3C V-phase and W-phase stator coils v1 to v3, w1 to w3
As can be seen from FIG. 14, the magnetic flux generated by the magnetic field stably forms a closed magnetic path P reciprocating between the rotor 2 in the magnetic poles 3A to 3C of each coil group, that is, in each of the stator blocks 11 to 13. . Therefore, the vector sum of the rotor attractive force (white arrow in FIG. 14) due to the positioning excitation current acts to always position the rotor 2 concentrically with respect to the stator 1, and the radial position of the rotor 2 is unexpected. There is no fluctuation.

On the other hand, the stator 1 is provided with a magnetic isolator 14.
If no .about.16 are provided, as shown in FIG. 15, the magnetic flux generated by one set coil due to the positioning excitation current is often combined with the magnetic flux generated by the other set coil, and the rotor 2 is straddled over the adjacent set coil. A magnetic path P ′ reciprocating between the two is formed.
As a result, the direction of the rotor suction force (white arrow in FIG. 15) changes, and the vector sum of these rotor suction forces is
15 to act to decenter the rotor 2 (see FIG. 15).
Black arrow), the radial position of the rotor 2 fluctuates unexpectedly.

In the above-described embodiment, the effect of the present invention has been described by taking the magnetic flux generated by the positioning excitation current as an example. However, the magnetic flux generated by the rotation excitation current is separated from the magnetic flux of each coil by providing a magnetic isolation unit. Unnecessary rotation torque fluctuation is prevented.

In the above-described embodiment, the non-magnetic plate is provided between the stator blocks to provide the magnetic isolation portion. However, the non-magnetic plate may not be provided, and this portion may be simply a gap. Alternatively, the stator may be formed as an annular one-piece, and the necessary portion may be made thin to be used as a magnetic isolation portion. In short, there is no particular structural limitation as long as the magnetic resistance of the magnetic isolation part is larger than the magnetic resistance between the stator part and the rotor part provided with each set coil.

Further, in the above embodiment, the magnetic isolation portion is provided so as to magnetically isolate the magnetic poles of each set coil composed of the three-phase stator coils. However, in the case where each phase stator coil is provided independently. It is preferable that a pair of coils forming a magnetic path for generating a radial force in these stator coils is provided as a set and a magnetic isolation portion is provided so as to magnetically isolate the magnetic poles.

[0032]

According to the bearing / rotary electric machine of the present invention,
By providing the magnetic isolation unit for magnetically isolating the stator coils and the assembled coils, unexpected fluctuations in the rotational torque and the radial position of the rotor can be reliably prevented, and stable operation can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a wiring structure of a stator coil.

FIG. 3 is a diagram illustrating a wiring structure of a stator coil.

FIG. 4 is a circuit diagram of a power supply circuit to a stator coil.

FIG. 5 is a waveform diagram of a command signal from a rotation drive controller.

FIG. 6 is a schematic diagram of a stator unit showing the magnitude and direction of a magnetic flux generated by a stator coil.

FIG. 7 is a schematic diagram of a stator unit showing the magnitude and direction of a magnetic flux generated by a stator coil.

FIG. 8 is a schematic diagram of a stator unit showing the magnitude and direction of a magnetic flux generated by a stator coil.

FIG. 9 is a diagram showing a phase relationship between vector currents.

FIG. 10 is a schematic diagram of a stator unit showing the magnitude and direction of a magnetic flux generated by a stator coil.

FIG. 11 is a schematic diagram of a stator unit showing a direction of a rotor suction force generated by a stator coil.

FIG. 12 is a schematic diagram of a stator unit showing a direction of a rotor suction force generated by a stator coil.

FIG. 13 is a schematic diagram of a stator unit showing a direction of a rotor suction force generated by a stator coil.

FIG. 14 is a schematic diagram of a main part of a rotating electrical machine depicting a magnetic path formed by a positioning excitation current of each coil group;

FIG. 15 is a schematic diagram of a main part of a rotating electric machine depicting a magnetic path in a conventional rotating electric machine in which a magnetic isolation unit is not provided on a stator.

[Explanation of symbols]

1 ... Stator, 11, 12, 13 ... Stator block,
14, 15, 16: magnetic isolation unit, 2: rotor, 3A, 3
B, 3C, 3D: assembled coil, 4A, 4B, 4C: three-phase inverter, 5: rotation drive controller, 51: rotation sensor, 6
... radial attitude controller, 61 ... displacement sensor, 7A, 7B,
7C, 7D... Two-phase inverter, u1, u2, u3, v1
, V2, v3, w1, w2, w3... Stator coils.

Continuing from the front page (72) Inventor Toshifumi Arakawa 41-cho, Chuchu-Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside of Toyota Central R & D Laboratories Co., Ltd. No. 1 Inside Toyota Central Research Institute Co., Ltd. (72) Inventor Yukio Inaguma 41-Cho, Yokomichi, Oji, Nagakute-cho, Aichi-gun, Aichi Prefecture No. 1 Inside Toyota Central Research Laboratory Co., Ltd. 1-41, Toyoda Central Research Laboratory Co., Ltd. F term (reference) 3J102 AA01 BA03 BA17 CA10 DA03 DA09 DA30 DB05 DB06 GA13 5H607 AA04 AA14 BB01 BB02 BB14 BB17 CC01 DD01 DD02 DD03 GG21 HH01 HH03 HH05

Claims (2)

[Claims] 1. A bearing / rotating electric machine which rotates while positioning a rotor in a radial direction by an electromagnetic field of a stator coil, wherein adjacent stators are arranged at intervals in a circumferential direction and generate mutually different radial forces. A bearing / rotating electric machine, wherein a magnetic isolation portion having a magnetic resistance larger than a magnetic resistance between a stator and a rotor of each stator coil installation portion is provided between magnetic poles of the coils. 2. A bearing / rotating electric machine that rotates while positioning a rotor in a radial direction by an electromagnetic field of a stator coil, wherein a plurality of stator coils having the same phase are arranged in a circumferential direction of the stator, and one end of the stator coils having different phases is connected to one end. Are connected to form a plurality of sets of coils, each of which is connected to an excitation current source such that the sum of currents at the connection points of the stator coils constituting the set coil becomes zero. The positioning excitation current and the rotation excitation current are superimposed on each other and supplied to each set coil, and between the magnetic poles of adjacent set coils, the magnetic resistance between the stator and rotor of each set coil installation part A rotating electric machine combined with a bearing, provided with a magnetic isolation portion having a large magnetic resistance.