JPS63242161A - Magnetic bearing motor of direct-acting type - Google Patents

Abstract

PURPOSE:To smoothly drive a slide at a high speed by exerting the same amount of magnetic force simultaneously, on its slide sections supported in a non- contact manner. CONSTITUTION:A direct-acting type magnetic-bearing motor is composed of a driving gear 28 connected to a load and driving the load, and a controller for controlling this driving and its bearing. The driving gear 28 is composed of a guide member 28A for a stationary guide section mounted on a stationary member 32 and set extensively along the specified slide direction A, and a slide section 28B guided in non-contact with the guide memher 28A. The slide section 28B is almost rectangularparallelopiped-formed, and is provided with a slide main-unit 34 having an almost-'T'-formed space B in the internal section, an electromagnet group in charge of a magnetic bearing, a slide driving electromagnet group, and an X, Y-directional distance sensor. As a result, the slide section 28B slides in a state that it is supported in non-contact with the stationary guide section 28A.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a direct-acting magnetic bearing motor, and particularly includes a sliding portion and a fixed guide portion that guides the slide portion, and the magnetic force of the fixed guide portion The present invention relates to a direct-acting magnetic bearing motor in which a sliding portion is slidably supported in a non-contact manner.

[Conventional technology]

Conventionally, various configurations of direct-acting magnetic bearing motors that have a sliding part and a fixed guide part that guides the sliding part have been developed and used. A configuration is adopted in which either one of the fixed guide parts is provided with a magnetic bearing part for non-contact support and a motor part for sliding drive. The magnetic bearing section and the motor section can be installed on separate pole pieces facing either the slide section or the fixed guide section, or on the same pole piece. There were configurations in which both excitation coils were wound, and configurations in which magnetic bearing and slide drive signals were applied in a superimposed manner to the same excitation coil wound around the same pole piece.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional technology, the device is large and complicated, and the orthogonal component of the slide driving force in the sliding direction changes the position of the magnetic bearing, causing vibrations and other problems, making it difficult to operate smoothly. There was a problem that it could not be made to slide. This problem has become particularly noticeable when high-speed slide driving is performed.

This invention was made by focusing on the problems of the prior art, and in particular, it almost completely eliminates the effect of the driving force for the slide drive □ on the positioning of the magnetic bearing.
The object of the present invention is to provide a direct-acting magnetic bearing motor that can perform positioning with higher precision and can slide smoothly and at high speed.

[Means for solving problems]

Therefore, in order to achieve the above object, the present invention includes a sliding part and a fixed guide part disposed slidably facing the sliding part and guiding the sliding part, and a part of the fixed guide part or the sliding part. A plurality of sets of pole pieces are each provided at equally spaced positions symmetrical to the other on the side facing the other, and each of the pole pieces is provided with an electromagnet for magnetic bearing, and the slide portion in a direct-acting magnetic bearing motor that is slidably supported in a non-contact manner with respect to the fixed guide part, on the side opposite to each of the pole pieces of either the slide part or the fixed guide part. protruding teeth having a predetermined pitch are uniformly formed, and pole piece tooth rows each consisting of pole piece teeth having a pitch different from that of the protruding teeth are provided on the side opposite to the protruding teeth of the plurality of sets of pole pieces; Among the sets of pole piece tooth rows, one set is arranged with a predetermined phase shift from the other adjacent set, and the adjacent pole piece teeth are arranged with respect to the pole piece teeth of the plurality of sets of pole piece tooth rows. Each set of excitation coils is wound so that the excitation coils are excited with opposite polarity to each other, and among the plurality of sets of excitation coils, each set of excitation coils that is symmetrical with respect to the sliding part or the fixed guide part is simultaneously excited by the same amount. It is equipped with a slide drive control section that supplies current.

[Effect]

In this invention, when the excitation current is sequentially supplied from the slide drive control unit to the excitation coils for slide drive for each set, the pole pieces of each pole piece tooth row are exposed to the adjacent teeth. are excited in opposite directions. Therefore, the lines of magnetic force caused by this excitation are either strengthened by the lines of magnetic force from the magnetic bearing electromagnet or weakened by the lines of magnetic force from the magnetic bearing electromagnet. At this time, the electromagnet connected to the pole piece tooth whose magnetic lines of force are strengthened attracts the adjacent protruding tooth. Since this is performed sequentially in multiple sets, the slide portion slides while being supported in a non-contact manner with respect to the fixed guide portion.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 12. This first embodiment shows a case where a magnetic bearing and an electromagnet for driving the slide are installed on the side of the sliding member.

In this embodiment, the direct-acting magnetic bearing motor includes a drive device 28 that is connected to and drives a load such as a direct-acting device, and a control device 30 that drives the drive device 28 and controls its magnetic bearing. ing.

The drive device 28 was mounted on the fixing member 32 and extended along a predetermined sliding direction A, as shown in FIGS. 1 to 3. Guide member 28 as a fixed guide part
A and the sliding direction A without contacting this guide member 28A.
The slide portion 28B is guided by the slide portion 28B.

Of these, the slide portion 28B includes a slide body 34 that is approximately rectangular parallelepiped and has a generally T-shaped space B therein;
Electromagnet groups 36, . . . , 36 that serve as magnetic bearings in the horizontal axis X direction (slide direction A is the plus Y direction), electromagnet groups 38°, 38 for slide driving, and vertical axis Z direction. electromagnets 40, . ..., 44.

In this embodiment, the electromagnet group 36. which acts as a magnetic bearing in the X direction.
..., 36 and slide drive electromagnet group 38, ...
, 38 are arranged in two groups at a predetermined distance apart from the inside surfaces of the slide body 34 on both sides, respectively, in a manner that they protrude into the space B (see FIG. 3). The electromagnets facing each other with the member 28A in between are arranged at equal positions with respect to the Y axis.

And electromagnet group 36. ..., 36 and 38. ...
.

38, each of the slide bodies 34 as shown in FIG.
Iron core 48. ..., 48. To explain this in detail, each iron core 48 has two rake-shaped pole pieces 48A and 48 formed on the left and right sides in FIG.
Each of the pole pieces 48A and 48B has six pole piece teeth a, .
・, f and a/.

... Pole tooth rows 48Aa and 48Ba consisting of f /
Each has As shown in FIG. 8, excitation coils 50a and 50b that generate magnetic poles in opposite directions are wound around the base of each pole piece 48A and 48B, thereby forming electromagnets 36a and 36b. There is. Moreover, each pole piece tooth row 48Aa.

48Ba has excitation coils 52a and 52b as shown in the figure so that adjacent teeth in one row of teeth have opposite polarity.
are wound separately, thereby forming electromagnets 38a and 38b. Here, iron core 48. . . , 48 are made of laminated silicon steel plates having a predetermined shape in order to reduce iron loss.

On the other hand, the slide body 34 in the guide member 28A
On both parallel sides of the side, the first. As shown in FIG. 8, protruding teeth 54 made of ferromagnetic material are perpendicular to the sliding direction A and have the same pitch. ..., 54 are formed.

Here, pole single teeth a, ..., f and a', ... f
L pitch (here, this is the standard 1 pitch)
is the protruding tooth 54. ..., 1/2 for 54 pitches
The pitch is set larger, and the pole tooth row is 48Aa, ---
, 48Aa is 48Ba, ..., 1 for 48Ba
They are arranged with a phase delayed by /4 pitch.

Therefore, in this embodiment, the pole piece tooth rows 48Aa and 48Aa facing each other via the guide member 28A, that is, the pole piece teeth a...
・, f and a, ..., f are in phase in the Y-axis direction,
Similarly, pole piece tooth rows 48Ba and 48Ba1, that is, pole piece tooth a
', -・, f' and a', +++, f
t are in the same phase in the Y-axis direction. And the eighth
As shown in the figure, 1 facing each other via the guide member 28A.
A pair of pole piece tooth rows 48Aa and 48Aa form a pair of pole piece tooth rows Kl, and an adjacent pair of pole piece tooth rows 48B
a and 48Ba form another set of pole piece tooth rows 2, and these two sets of pole piece tooth rows K1 and 2 form a basic group for sliding drive. In this embodiment, two basic groups are provided. In addition, the electromagnet 3 facing the guide member 28A
6a and 36a1 and 36b and 36b are in the same phase in the Y-axis direction.

On the other hand, an electromagnet 40 that serves as a magnetic bearing in the Z direction. ....

40 respectively, as shown in FIG. 2.3, the slide body 3
Iron cores 60.4 are provided at predetermined positions on both sides of the bottom of the inner surface of the guide member 28A in close proximity to and opposite to the guide member 28A.・・・
・, 60, and this iron core 60. ....

Excitation coils 62 . ..., 62 constitute four groups.

On the other hand, the X-direction distance sensor 42.42 is connected to the slide body 34.
Both sides of the inner side (front and rear sides in sliding direction A: hereinafter referred to as the "front side" of the car).

Z-direction distance sensor 44. . . , 44 are both sides of the inner bottom of both exits of the slide body 34 (front, front cloth, rear left, rear right with respect to the sliding direction A: hereinafter, these will be simply referred to as "front", "
A total of four pieces are erected on the front cloth, rear left, and rear right. Each of these sensors 42 and 44 outputs to the control device 30 displacement signals dx and dz that are analog voltage signals corresponding to the distance from the slide body 34 to the guide member 28A. Here, each sensor 4
The reason why a plurality of numerals 2 and 44 are provided is to control the inclination of the slide member 28B in each direction.

Here, each sensor 42, 44 outputs a displacement signal dxo of a predetermined reference value when the slide portion 28B is at a predetermined reference position for sliding.

dzo, and when the sensor position is displaced such that the distance from the reference position to the sensor position becomes large or small, displacement signals dx, dz smaller or larger than the reference value are output.

Next, the configuration of the control device 30 will be explained.

As shown in FIG. 4, the control device 30 inputs the front side and rear side X direction displacement signals dx, and performs the front side and rear side X direction positioning 7 based on this. The front to rear right Z direction positioning unit 30ZFL inputs the Z direction displacement signal dz at the front to rear right positions to the parts 30xr and 30X, and performs positioning in the Z direction at each of the front to rear right positions based on this. ~30ZRR, and a slide drive control section 30S that controls the slide drive of the slide section 28B.

Among these, front side and rear side X direction positioning parts 30X, and 3
0XR is configured as shown in FIG. To explain this in detail using the rear X-direction positioning section 30XR as an example, the displacement amount and displacement direction from the reference position in the X direction are calculated based on the X-direction displacement signal dx output from the rear X-direction distance sensor 42. and an X-direction displacement difference calculation means 72 that calculates a displacement difference signal Δdx corresponding to this, and an X-direction magnetic bearing control that outputs a positioning signal to be described later based on the displacement difference signal Δdx from the X-direction displacement difference calculation means 72. Means 74
The positioning signal from the X-direction magnetic bearing control means 74 is amplified (amplification factor α) and the excitation coil 50 for the bearing is
A, 50b, 50a, and 50b are configured by power amplifiers 76A and 76B that output excitation currents, respectively.

The X-direction displacement difference calculation means 72 includes a low-pass filter 84 that removes noise from the input X-direction displacement signal dx, a phase compensation circuit 86 that compensates for the phase of the output of the low-pass filter 84, and a phase compensation circuit 86 that compensates for the phase of the output of the low-pass filter 84. The output of the circuit 86 is compared with the reference signal v3°8 corresponding to the reference position in the X direction, and a displacement difference signal Δdx=V. , -dx.

The X-direction magnetic bearing control means 74 also includes a PID circuit 90 (proportional circuit 90p, integral circuit 90i,
an adder circuit 92 for adding the PI calculation output signal and ID calculation output signal from the PID circuit 90 to obtain an addition signal y ix;
An addition circuit 94 that adds the addition signals V, X and the reference bias signal v08 to output a positioning signal rvtl -Vi,
, J.

The output side of the adder circuit 9-4 is a power amplifier 76.
The excitation coil r50 on the right side of the slide portion 28B via A
Connected to ground via a+50bJ.

The output side of the subtraction circuit 95 is connected to the excitation coil r50a+5 on the left side of the slide portion 28B via the power amplifier 76B.
Connected to ground via 0bJ.

Here, the front side X-direction positioning section 30XF is configured similarly to the rear side X-direction positioning section 30XR described above.

Similarly, the front-rear right Z direction positioning parts 30ZFL to 30Z, 1, 1 are configured as shown in FIG. To explain this in detail using the rear left Z direction positioning section 30ZRL as an example, this positioning section 30ZRL is
Z-direction displacement difference calculation that calculates the displacement amount and displacement direction from the reference position in the Z-direction based on the Z-direction displacement signal dz output from the rear left Z-direction distance sensor 44, and calculates the corresponding displacement difference signal Δdz. a Z-direction magnetic bearing control means 80 that outputs a positioning signal, which will be described later, based on a displacement difference signal Δdz from the Z-direction displacement difference calculating means 78; The power amplifier 82 amplifies (amplification factor α) and outputs an excitation current to the excitation coil 62 for the bearing.

Of these, the Z direction displacement difference calculation means 78 is the
As in the case of the direction, a low pass filter 96, a phase compensation circuit 98 . It is configured with a comparison circuit 100, and has a reference signal ■8°2 corresponding to the reference position in the Z direction, and a displacement signal dz.
A displacement difference signal Δdz corresponding to the amount of displacement and its direction is output by comparison with . In addition, the two-way magnetic bearing control means 80
As in the case of the X direction described above, is configured with a PI[) calculation circuit 102 and adder circuits 104 and 106, and processes the input displacement difference signal Δdz to generate a positioning signal r V
s+z'' V izJ is set to be output to the power amplifier 82 (amplification factor α).The output side of the power amplifier 82 is connected to the ground via the excitation coil 62 for the bearing.

Here, each of the Z-direction positioning parts 30 for the front person, front cloth, and rear right
ZFL, 30 ZFR, and 30ZRII are configured similarly to the rear left Z direction positioning section 3-OZ*t described above.

Furthermore, as shown in FIG. 7, the slide drive control section 30S includes an oscillator 128 that oscillates a square wave,
A square wave is extracted at a predetermined timing from the square wave train that is the output of 8, and is used as the first to fourth slide drive signals V.
, ~ ■4, and an inverting circuit 132 and 134 for inverting the signals for outputs v3 and ■4 of the third and fourth months among the outputs of this timing circuit 130. and power amplifiers 136A to 136D (amplification factor α) that amplify the first to fourth slide drive signals ■1 to v4, respectively. Here, each slide drive signal V, -V4 is synchronized with the falling or rising edge of the previous signal, respectively.
The next signal sequentially rises or falls from the ground level to a predetermined level.

The output sides of the power amplifiers 136A and 136C are both connected to the ground via two groups of excitation coils 52a, 52a and 52a, 52a arranged facing each other for driving the slide, forming a closed circuit. ing. Also,
The output sides of the power amplifiers 136B and 136D are both connected to the ground via two groups of excitation coils 52b, 52b and 52b, 52b arranged facing each other for driving slides, forming a closed circuit. .

Next, the operation of this embodiment will be explained.

When the power of this device is turned on, each electric circuit is turned on, and magnetic bearing operation and slide drive operation are started.

First, the operation of the magnetic bearing will be explained.

When the power is turned on, the X-direction distance sensor 42, 42 and the two-direction distance sensor 44 equipped on the slide portion 28B
．． ..., 44 are guide members 2 for each direction component.
72 and 78. ..., output to 78.

Here, X-direction control on the rear side will be explained as an example. The X-direction displacement signal dx is generated by the X-direction displacement difference calculation means 7.
2, - As described above, the displacement difference signal Δdx is converted into a positive or negative displacement signal Δdx depending on the direction and amount in which the slide portion 28B is displaced from the reference position with respect to the guide member 28A, and X-direction magnetic bearing control is performed. It is output to means 74.

Then, the displacement difference signal Δdx is processed as described above in the X-direction magnetic bearing control means 74, and the positioning signal r
V@, x + VtxJ, r Vs+* Vtx
J is output to power amplifiers 76A and 76B, respectively. These positioning signals rV, , X+V, XJ and r v
-+Xvi" are power amplifiers 76A and 76, respectively.
B is multiplied by α, excitation coil “50a+50b” and r5
0a+50bJ is applied to each column, so that the strength of the magnetic force is opposite on the left and right sides of the guide member 28A.

For example, if the slide portion 28B is plus X from its reference position,
If it is displaced by θ in the axial direction (that is, displaced to the right in Fig. 5), the displacement signal dx becomes larger than the reference signal V8°8, and Δdx and V□ take negative values. Become. Therefore, "V□X+ViXJ becomes smaller than the value v8□ at the reference position, and conversely
VtxJ is the value at the reference position ■, 1. Become bigger. Therefore, the attraction force for the guide member 28A is strengthened in the left coil r50a+50bJ, and the attraction force is weakened in the right coil r50a+50bJ, and the rear side of the slide portion 28B is eventually returned to the left side in FIG. 5.

On the contrary, if the rear side of the slide portion 28B is displaced to the left in FIG. 5 from its reference position, the displacement signal dx becomes smaller than the reference signal V saw, and Δd
x and vix take positive values. For this reason, “■□ and +V
iX" becomes larger than the value V s + x at the reference position, and conversely, rV, , -V, , J becomes smaller than the value V s I x at the reference position, acting contrary to the above, the sliding portion The rear side of 28B is returned to the right side.

The above-described position control is similarly performed independently on the front side of the slide portion 28B, and the inclination thereof is also corrected.

In this way, the slide portion 28B is held at the position where the magnetic forces are balanced, that is, at the reference position. When positioned at this reference position, the displacement signal dx=reference signal V.

8, the value y ix found from the displacement signal dx
becomes zero. For this reason, the excitation coil r5 for the left and right bearings
The positioning signals applied to each column of 0a+50bJ, . . . , r50a+50bJ are equal to αV S
IX, which is balanced on both the left and right sides, and the slide portion 28B is held at the reference position as it is.

By the way, FIG. 8 shows a magnetic circuit formed by the electromagnets 36a, 36b and 36a, 36b for X-direction support in the state of holding at the above-mentioned reference position.

The electromagnets 36a, 36b and 36a, 36b are alternately excited to have opposite polarities, as shown in the figure.

At this time, for example, a line of magnetic force (see the dotted line in the figure) emerging from the N pole of the right electromagnet 36b passes through the back side portion 48K of the iron core 48 and enters the S pole of the adjacent electromagnet 36a. The lines of magnetic force coming out from the N pole of the electromagnet 36a each form a pole piece tooth a.

..., f, gap, protruding tooth 54° of guide member 28A.
..., 54, guide member 28A, protruding tooth 54° again
. . , 54, the air gap, and the pole piece teeth a', .

Further, the electromagnets 36a and 36b on the left side facing this form a closed loop as shown by the dotted line arrow in the figure in the same manner as described above.

At this time, as described above, each pole piece tooth row 48Aa and 4
8Ba has protruding teeth 54. ..., the phase is shifted by 1/2 pift with respect to 54, and each pole piece tooth row 48Aa is 4
Since the phase is shifted by 1/4 pift with respect to 8Ba, for example, the position shown in FIG. 8 (pole teeth a, c on the left and right electromagnets 36a)

e and the phase of every second protruding tooth 54, 54.54 matches). In this way, the magnetic forces caused by the electromagnets 36as36a, 36b, and 36b facing each other are balanced (the same applies to other sets of electromagnets), and the slide portion 28B is held in the X direction in a non-contact manner.

Further, the operation of the magnetic bearings in the Z direction from the front to the rear right side is performed in the same manner as described above. That is, based on the Z-direction displacement signal dz detected according to the Z-direction displacement amount and displacement direction of the slide portion 28B with respect to the guide member 28A, the positioning signal α (View + Vig
) is formed. Then, the signal α (vs+z''V,,) is set small or large depending on the magnitude of the signal dz, and is balanced with the own weight of the slide part 28B, so that the displacement of the slide part 28B in the Z direction is corrected and returned to the reference position. At this time, this positioning is from the front to the rear right side.
Since the correction is performed independently at several locations, the positioning and inclination of the slide portion 28B in the Z direction and the inclination in the Z direction are also corrected.

With the above operation, the slide portion 28B moves to the position X.

It is supported in a non-contact manner in the Y direction and the Z direction, and is precisely positioned at a predetermined reference position.

On the other hand, when the slide portion 28B deviates from its slide reference position due to external disturbances such as load fluctuations in slide driving, etc., which will be described later, this displacement situation is detected by each sensor 42, 42.
．． 44. . . , 44, and based on this, the same position correction operation as described above is executed. Therefore, the slide portion immediately returns to its original reference position.

Next, the slide driving operation will be explained based on FIGS. 9 to 12. These diagrams represent one of the basic groups mentioned above.
I will show you about one.

First, in the state shown in FIG. 8 described above, when the slide drive signal (2) is simultaneously supplied from the slide drive control section 30S to only the input terminals IN of the excitation coils 52a, 52a for slide drive on both the left and right sides, Excitation current flows as shown in Figure 9. At this time, at the pole pieces a, c, and e of both electromagnets 38a, the lines of magnetic force due to the electromagnet 36a and the electromagnet 38a
Since the lines of magnetic force due to the magnetic field are in the same direction, they are strengthened and reversed.

In the pole pieces d and f, the lines of magnetic force are in opposite directions, so they are canceled out or weakened. At this time, adjacent electromagnets 38b, 3
8b is in a non-excited state, and the protruding tooth 54. ..., 5
Focusing on arbitrary teeth ■ and ■ in Figure 9 of 4,
-These teeth ■ and ■ are pole single teeth d l.

They are each located at a distance of 1/4 pitch from d' and are the closest.

From the above state, as shown in Figure 10, the slide drive signal ■
The slide drive signal v2 is simultaneously applied only to the input terminals IN of the coils 52b and 52b in synchronization with the falling edge of the signal V1. As a result, the pole piece tooth b' of the left and right electromagnets 38b is
, d', and M, the lines of magnetic force are strengthened by the electromagnet 38b, and the lines of magnetic force are canceled out or weakened at the pole teeth a', ', and e'. For this reason, the pole piece teeth d', d' are attracted by the aforementioned teeth (2), (2), respectively, and reach the positions of the protruding teeth (2), (3). That is, the entire slide portion 28B has slid in the sliding direction A by 1/4 pitch. At this time, if we pay attention to arbitrary other teeth ■, ■ in FIG. 10 among the protruding teeth 54, . for,
The closest one is at a distance of 1/4 pitch.

Furthermore, from the above state, as shown in FIG. 1), the slide drive signal V
, are again simultaneously applied only to the input terminals IN of the coils 52a, 52a. As a result, both electromagnets 38a are excited in the opposite direction to that shown in FIG. 9 described above. For this reason, one pole tooth f, f
is attracted to the contact surfaces ■ and ■ by the magnetic force of the teeth ■ and ■ described above. That is, the entire slide portion 28B further slides in the sliding direction A by 1/4 pitch. At this time,
In both electromagnets 38b, the tooth ■ after ■ and ■.

■ is closest to the pole teeth c l and c / at a distance of 1/4 pitch from each other.

Furthermore, from the above state, as shown in FIG. 12, the slide drive signal v4 is simultaneously applied only to the IN of the coils 52b and 52b in synchronization with the rise of the slide drive signal v3. As a result, the left and right electromagnets 38b are excited in the opposite direction to that shown in FIG. 10 described above. For this reason, the pole tooth C′
, C' is in contact with the contact surfaces ■, ■ due to the magnetic force from the teeth ■, ■ mentioned above.
It is sucked up to the position. That is, the entire slide portion 28B further slides in the sliding direction A by 174 pitches.

In this way, by repeatedly inputting the slide drive signals (1) to (4), the slide operations shown in FIGS. 9 to 12 described above are repeated, and this operation is performed by the electromagnets 38a of the other group (two sets).

38b, 38a, and 38b are also done in the same way, so
The slide portion 28B slides substantially continuously in the slide direction A. At this time, the X-direction component of the attractive force accompanying the slide drive is canceled out for each set on both the left and right sides of the slide portion 28B, so that no effect that causes the position change of the magnetic bearing described above occurs. becomes. Further, by shortening the repetition period of the slide drive signals (1) to (4), it is possible to slide at a higher speed.

As described above, this embodiment has various advantages. First, a slide driving force due to magnetic force is applied to the slide portion 28 at symmetrically opposing positions via the slide member 28A.
B, the X-direction component of the slide driving force is canceled out, and there is no effect on the magnetic bearing position due to changes in the magnetic bearing position due to sliding. It can be done with precision and can be slid at high speed. Along with this,
Since the suction drive is performed on both sides of the guide member 28A,
Larger torque can be obtained compared to the case of only one of them. Furthermore, between the protruding teeth of the guide member 28A and the pole piece teeth of the slide portion 28B, the teeth whose phases match each other are distributed almost evenly on both the left and right sides. Compared to the case where the teeth are localized, the distortion of the slide portion 28B can be made smaller, and this also facilitates highly accurate position control and high-speed driving of the slide portion 28B.

In addition, excitation coils 52a, . . . for driving the slide.

52a and 52b, ., 52b are pole pieces 48A.

..., 48A, 48B, ..., 48B are wound around the pole piece teeth a,..., f and al,..., f', respectively, so that the excitation for the bearing is Coil 50a...
・.

Since a closed magnetic path different from the closed magnetic path formed by 50a and 50b, . . . , 50b is formed, the excitation coils 50a, ..., 50a and 50b,
..., it is less likely that a back electromotive force will be generated in 50b and the magnetic bearing operation will be disturbed (therefore, the corresponding signals ■1 to V4
By shortening the repetition period, high-speed driving can be achieved.

Furthermore, the pole piece teeth a on the side of the slide portion 28B, . . .

f and a', . . . f / are not just magnetic paths, but excitation coils 52a, .
and 52b, . . . , 52b are wound and actively utilized, so the pole pieces teeth a, . . . , f and a′.

. . . The coil 52a is located at a different position from M.

It also has the advantage that the entire drive device 28 can be made more compact compared to the case where the windings 52a, 52b, . . . , 52b are wound.

Next, the second and third embodiments will be explained.

First, in the second embodiment, in the first embodiment described above, at the start of slide drive, the excitation coil 50a for the bearing,
, 50a, 50b, -, 50b, a configuration is added in which slide drive signals V, to V4 (both positive or negative pulse signals) are applied superimposed on the bearing signal. According to this, the effect is equivalent to that of the above-mentioned embodiment, and also has the advantage that the slide start torque can be increased.

Further, as a third embodiment, in the first embodiment described above, a permanent magnet is used as the magnetic bearing electromagnet, and the slide drive coils 52a, . . . , 52a and 52b, .
. , 52b are coils with as low inductance as possible. According to this, the effect is equivalent to that of the first embodiment described above, and the slide drive signals V, -
At the rise or fall of V4, the self-induced back electromotive force generated in the coil becomes smaller, making it possible to further increase the rigidity.

In each of the embodiments described above, the electromagnets for magnetic bearings and for driving the slide were provided on the slide portion 28B side, but the present invention is not necessarily limited to this, and they may be provided on the guide member 28A side. . - Furthermore, in each of the embodiments described above, the number of groups of electromagnets for driving the slide, the pitch of the protruding teeth and the pole piece teeth, and the phase shift of the pole piece teeth are not necessarily limited to those described above.

〔Effect of the invention〕

As explained above, according to the present invention, while the slide part is supported in a non-contact manner, magnetic force for driving the slide is simultaneously applied to the slide part by the same amount from a symmetrical position with respect to the slide part, By repeating this in multiple sets to drive the slide part, the component orthogonal to the sliding direction of the driving force acting on the slide part is almost completely balanced, so the slide position of the magnetic bearing changes, etc. It is possible to almost completely eliminate the situation where the magnetic bearing is affected, which allows for more accurate positioning in the sliding direction.On the other hand, the closed magnetic path for the magnetic bearing and the closed magnetic path for the slide drive do not overlap. , it is possible to avoid the situation where the excitation current for driving the slide disturbs the magnetic path of the magnetic bearing.
This makes it possible to switch over the excitation coils for multiple sets of slide drives at higher speeds, which is an advantage in that it is possible to obtain a direct-acting magnetic bearing motor that runs smoother and at higher speeds than the conventional technology. You can get the same effect.

[Brief explanation of drawings]

FIG. 1 is a perspective view 1 schematically showing a drive device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line n-■ in FIG. 1, and FIG. 4 is a block diagram showing the control device of the first embodiment, and FIG. 5 is a block diagram of the X-direction positioning section of the control device in FIG. 4. , FIG. 6 is a block diagram of the Z-direction positioning section of the control device in FIG. 4, FIG. 7 is a block diagram of the slide drive control section of the control device in FIG. 4, and FIG. 8 is a magnetic bearing state. 9 to 1 are explanatory diagrams showing a part of the magnetic circuit of
FIG. 2 is an explanatory diagram for explaining the slide driving operation. In the figure, 28A is a guide member as a fixed guide part, 28B
303 is a slide portion, 303 is a slide drive control portion, and 36.・
..., 36 is an electromagnet for X-direction support, 38, ..., 3
8 is an electromagnet for driving the slide, 40°..., 40 is Z
Electromagnet for directional support, 48A,... 48A, 48B, 48B is a pole piece, 48Aa. ...-48Aa, 48Ba, +/+, 48Ba are pole single tooth rows, 54. ..., 54 is a protruding tooth, 52a, ...,
52a, 52b, . . . , 52b are excitation coils for driving the slide, and a, . . . , f, a', .

Claims (1)

[Claims] (1) Comprising a sliding part and a fixed guide part disposed opposite to the sliding part and guiding the sliding part, and on the side of either the fixed guide part or the sliding part facing the other. A plurality of sets of pole pieces are provided at equidistant positions symmetrical to the other pole pieces, and each pole piece is provided with an electromagnet for magnetic bearing, so that the sliding part does not come into contact with the fixed guide part. In a direct-acting magnetic bearing motor that is slidably supported in a linear motion type magnetic bearing motor, protruding teeth with a predetermined pitch are uniformly formed on the side of either the sliding portion or the fixed guide portion facing the respective pole pieces. , a pole piece tooth row consisting of pole piece teeth having a pitch different from that of the protruding teeth is provided on the side opposite to the protruding teeth of the plurality of pole pieces, and one of the plurality of pole piece tooth rows is provided. The pairs are arranged with a predetermined phase shift with respect to the other adjacent pair, and the adjacent pole teeth of the plurality of pairs of pole piece tooth rows are excited with mutually opposite polarities. A slide drive control unit is provided, in which excitation coils are respectively wound so as to simultaneously supply the same amount of excitation current to each set of excitation coils that are symmetrical with respect to the slide part or the fixed guide part among the plurality of sets of excitation coils. A direct-acting magnetic bearing motor characterized by: