JPH0787688B2 - Direct acting magnetic bearing motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct-acting magnetic bearing motor, and more particularly to a slide portion and a fixed guide portion for guiding the same, and a magnetic force of the fixed guide portion is used. The present invention relates to a direct acting type magnetic bearing motor in which a slide portion is slidably supported in a non-contact state.

[Conventional technology]

Conventionally, various types of direct-acting magnetic bearing motors having a slide portion and a fixed guide portion for guiding the slide portion have been developed and used, but most of them have a slide portion or a fixed portion. A magnetic bearing portion for non-contact support and a motor portion for slide driving are provided on either one of the guide portions. And, as a method of equipping the magnetic bearing portion and the motor portion, one having a constitution in which the pole piece is separately provided so as to face either the slide portion or the fixed guide portion, or the same pole piece is provided. There are a structure in which both exciting coils are wound, and a structure in which signals for a magnetic bearing and a slide driving are superimposed and applied to the same exciting coil wound around the same pole piece.

[Problems to be solved by the invention]

However, in the above-described 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, so that vibration or the like occurs, which causes a smooth movement. There was a problem that it was not possible to slide. This problem is especially
This was remarkable when high-speed slide driving was performed.

The present invention has been made by paying attention to such problems of the prior art, and in particular, substantially completely eliminates the influence of the driving force for slide driving on the positioning of the magnetic bearing, and makes the positioning more accurate. It is an object of the present invention to provide a direct-acting magnetic bearing motor that can perform well and can perform smooth and high-speed slide driving.

[Means for solving problems]

Therefore, in order to achieve the above object, the present invention includes a slide portion and a fixed guide portion that is disposed so as to face the slide portion and guides the slide portion. A plurality of pairs of pole pieces are provided at equally spaced positions that are symmetric with respect to the other on the side facing one of the other, and each of the pole pieces is provided with a magnetic bearing electromagnet. In a direct acting magnetic bearing motor in which a portion is slidably supported on the fixed guide portion in a non-contact manner, a side of the slide portion or the fixed guide portion facing each of the pole pieces. Protruding teeth of a predetermined pitch are uniformly formed on each of the plurality of sets of pole pieces, and a pole piece tooth row composed of pole piece teeth having a pitch different from that of the projecting teeth is provided on each side of the plurality of pole pieces facing the projecting tooth. One of multiple pole tooth rows The exciting coil is arranged with a predetermined phase shift with respect to the other adjacent pair, and the adjacent pole piece teeth are excited with mutually opposite polarities with respect to the pole piece teeth of the plurality of pairs of pole piece teeth. Each of the plurality of sets of exciting coils is provided with a slide drive controller that supplies the same amount of exciting current to each set exciting coil symmetrical with respect to the slide part or the fixed guide part.

[Action]

According to the present invention, when the exciting current is sequentially supplied from the slide drive control unit to the plural sets of exciting coils for slide driving in each set, the pole piece teeth of each pole piece tooth row are adjacent to each other. They are excited in opposite directions. For this reason, the magnetic field lines due to this excitation are strengthened by the magnetic field lines from the magnetic bearing electromagnet, and weakened by the magnetic field lines. At this time, the electromagnet applied to the one pole tooth where the magnetic force line is strengthened attracts the adjacent protruding tooth. Then, this is sequentially performed in a plurality of sets, so that the slide portion slides in a state of being supported by the fixed guide portion in a non-contact manner.

〔Example〕

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

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

As shown in FIGS. 1 to 3, the drive device 28 is mounted on the fixing member 32 and extends along a predetermined sliding direction A, and serves as a guide member 28A as a fixed guide portion.
This guide member 28A is constituted by a slide portion 28B which is guided in the slide direction A in a non-contact manner.

Among them, the slide portion 28B has a slide body 34 having a substantially rectangular parallelepiped shape and having a substantially T-shaped space B therein, and a magnetic bearing in the horizontal axis X direction (the slide direction A is a plus Y direction). , 36, the electromagnet groups 38, ..., 38 for driving the slide, and the electromagnet 4 which serves as the magnetic bearing in the vertical axis Z direction.
0, ..., 40 and X to the guide member 28A of the slide body 34
Direction distance sensor for detecting distance displacement in the Z and Z directions
42, 42 and Z-direction distance sensors 44, ..., 44.

In this embodiment, electromagnet groups 36, ...
36 and slide driving electromagnet groups 38, ..., 38 are arranged in groups of two at a predetermined distance from the inner side surfaces of the slide body 34 so as to project into the space B (see FIG. 3). ) Moreover, the electromagnets facing each other through the guide member 28A on both side surfaces thereof are arranged at the same position with respect to the Y axis.

Each of the electromagnet groups 36, ..., 36 and 38 ,.
As shown in the figure, iron cores 48, ..., 48 projecting from the inside of the slide body 34 are formed. More specifically, each iron core 48 has two hand-shaped pole pieces 48A and 48B formed on the left and right in FIG. 8, and these pole pieces 48A and 48B are provided on the guide member 28A side. Six pole teeth a, ...
, f ', which have pole piece teeth rows 48Aa and 48Ba, respectively. Then, as shown in FIG. 8, exciting coils 50a and 50b for generating magnetic poles in opposite directions are wound around the roots of the pole pieces 48A and 48B, respectively.
a and 36b are formed. Further, as shown in the figure, exciting coils 52a and 52b are separately wound around the pole piece tooth rows 48Aa and 48Ba so that adjacent teeth in one tooth row have mutually opposite polarities. , 38b are formed. Here, the iron cores 48, ..., 48 are formed by laminating silicon steel plates having a predetermined shape in order to reduce iron loss.

On the other hand, as shown in FIGS. 1 and 8, on both parallel side surfaces of the guide member 28A on the slide body 34 side, as shown in FIGS.
54, ..., 54 are formed.

Here, the pitch of the pole single teeth a, ..., F and a ′, ..., F ′ (this is one reference pitch here) is defined by the protruding teeth 54 ,.
.., 48Aa are arranged with a phase delayed by 1/4 pitch with respect to 48Ba, ..., 48Ba.

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 ,. , The pole tooth rows 48Ba and 48B
That is, a, that is, the pole piece teeth a ′, ..., F ′ and a ′, ..., F ′ are in the same phase in the Y-axis direction. Then, as shown in FIG. 8, a pair of pole piece tooth rows 48A facing each other through the guide member 28A.
a, 48Aa forms one set of pole piece teeth K1, and a pair of adjacent pole piece teeth rows 48Ba, 48Ba forms another set of pole piece teeth K2. These two sets of pole piece teeth The columns K1 and K2 form a basic group for driving a slide. In this embodiment, two basic groups are arranged. Further, the electromagnets 36a and 36a and the electromagnets 36b and 36b facing each other through the guide member 28A have the same phase in the Y-axis direction.

On the other hand, the electromagnets 40, ...
As shown in FIGS. 2 and 3, iron cores 60, ..., 60 provided at predetermined positions on both sides of the bottom of the inner surface side of the slide body 34 so as to closely face the guide member 28A, and the iron cores 60, 60, …, 60
The exciting coils 62, ...

On the other hand, the X-direction distance sensors 42, 42 are both outlets on one side surface inside the slide body 34 (front side and rear side in the sliding direction A:
Hereinafter, this is simply erected in the vicinity of “front side” and “rear side”, and the Z direction distance sensors 44, ..., 44 are provided on both sides (sliding direction) of the inner surface side bottom part of both outlets of the slide body 34. Front left, front right, rear left, rear right with respect to A: Hereinafter, these are simply referred to as "front left", "front right", "rear left", and "rear right"), and a total of four are erected. ing. Each of these sensors 42, 44 outputs displacement signals dx, dz, which are analog voltage signals corresponding to the distance from the slide body 34 to the guide member 2A, to the control device 3
It is designed to output to 0. Where each sensor 42,44
Is provided with a plurality of slide members 28B.
This is for controlling the inclination of each of the directions.

Here, each sensor 42,44 outputs a displacement signal dxo, dzo of a predetermined reference value when the slide portion 28B is at a predetermined reference position for sliding, and from this reference position to the sensor position. When the displacement is such that the distance is large or small, the displacement signals dx and dz smaller or larger than the reference value are output.

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

As shown in FIG. 4, the control device 30 controls the front side X and the rear side X.
The front and rear X-direction positioning portions 30X _F and 30X _R for inputting the directional displacement signal dx and positioning the front and rear X-directions based on this signal, and the Z-direction displacement signal at the front left to rear right positions Front left-rear right Z-direction positioning unit that inputs dz and positions the front left-rear right in the Z-direction based on this
30Z _{FL to} 30Z _RR and a slide drive control unit 30S that controls the slide drive of the slide unit 28B.

Of these, the front and rear X-direction positioning parts 30X _F and 30X
_R is constructed as shown in FIG. This will be described in detail by taking the rear side X direction positioning portion 30X _R as an example. The X direction displacement signal dx output from the rear side X direction distance sensor 42.
X-direction displacement difference calculating means 72 for calculating the displacement amount and displacement direction from the reference position in the X-direction and calculating the displacement left signal Δdx corresponding thereto, and the displacement difference signal from this X-direction displacement difference calculating means 72 X-direction magnetic bearing control means 74 for outputting a positioning signal to be described later based on Δdx, and the excitation coils 50a, 50b for bearings which amplify (amplification factor α) the positioning signal from the X-direction magnetic bearing control means 74, The power amplifiers 76A and 76B output exciting currents to 50a and 50b, respectively.

Then, the X-direction displacement difference calculating means 72 removes noise from the input X-direction displacement signal dx.
And a phase compensation circuit 86 for compensating the phase of the output of the low-pass filter 84 and the output of the phase compensation circuit 86 and the reference signal V _sox corresponding to the reference position in the X direction, and the displacement difference signal Δdx = V _sox And a comparison circuit 88 for performing -dx operation.

The X-direction magnetic bearing control means 74 includes a PID circuit 90 (comprising a proportional circuit 90p, an integrating circuit 90i, and a differentiating circuit 90d) that performs PI calculation and ID calculation on the input X-direction displacement difference signal Δdx. and an adding circuit 92 to obtain a sum signal V _ix by adding the PI operation output signal and the ID calculating an output signal from the PID circuit 90, furthermore, the addition signal V _ix and the reference bias signal V _slx
And the addition circuit 94 that outputs the positioning signal “V _slx + V _ix ” and the arithmetic circuit that subtracts the addition signal V _ix from the reference bias signal V _slx and outputs the positioning signal “V _slx −V _ix ” It has 95 and.

Then, the output side of the adding circuit 94 reaches the ground via the power amplifier 76A and the exciting coil "50a + 50b" on the right side of the slide portion 28B. The output side of the subtraction circuit 95 reaches the ground via the power amplifier 76B and the exciting coil "50a + 50b" on the left side of the slide portion 28B.

Here, the front side X direction positioning portion 30X _F is the rear side X described above.
It has the same structure as the direction positioning unit 30X _R.

Also, in the same way as this, the front left to rear right Z direction positioning portion
30Z _{FL to} 30Z _RR are configured as shown in FIG. This will be described in detail by taking the rear left Z-direction positioning unit 30Z _RL as an example. This positioning unit 30Z _RL is based on the Z-direction displacement signal dz output from the rear left Z-direction distance sensor 44, and from the Z-direction reference position. Z-direction displacement difference calculating means 78 for calculating the displacement amount and the displacement direction of the
And the displacement difference signal Δdz from the Z direction displacement difference calculating means 78.
Z direction magnetic bearing control means 80 which outputs a positioning signal described later based on the above, and a positioning signal from this Z direction magnetic bearing control means 80 is amplified (amplification factor α) and an exciting current is applied to the exciting coil 62 for bearing. It is composed of a power amplifier 82 for outputting.

Of these, the Z-direction displacement difference calculating means 78 is similar to the case of the above-mentioned X-direction, and the low-pass filter 96 and the phase compensation circuit 9
8. Comparing the reference signal V _soz corresponding to the reference position in the Z direction with the displacement signal dz, the comparator circuit 100 is configured to output a displacement difference signal Δdz corresponding to the displacement amount and its direction.
Further, the Z direction magnetic bearing control means 80 is configured to have the PID calculation circuit 102 and the addition circuits 104 and 106, as in the case of the X direction described above, and processes the input displacement difference signal Δdz to determine the positioning signal “V”. _slz + V _iz "is output to the power amplifier 82 (amplification factor α). Of these, the power amplifier
The output side of 82 reaches the ground through the exciting coil 62 for the bearing.

Here, front left, front right, rear right Z-direction positioning portions 30Z _FL ,
The 30Z _FR and 30Z _RR are configured in the same manner as the above-mentioned rear left Z-direction positioning portion 30Z _RL .

Further, as shown in FIG. 7, the slide drive control unit 30S extracts a square wave from the oscillator 128 that oscillates a square wave and a square wave train that is the output of the oscillator 128 at predetermined timings, and extracts the square wave. For the timing circuit 130 that outputs the _{first to} fourth slide drive signals V _{1 to} V ₄ in parallel, and for the third and fourth outputs V ₃ and V ₄ of the outputs of the timing circuit 130, Inverting circuits 132 and 134 for inverting the signals, and power amplifiers 136A to 136D (amplification rate α) for individually amplifying the _{first to} fourth slide drive signals V _{1 to} V ₄ are provided. . Here, each slide drive signal V _{1 to} V ₄
Respectively, the next signal sequentially rises or falls from the ground level to a predetermined level in synchronization with the fall or rise of the previous signal.

Then, the output sides of the power amplifiers 136A and 136C both reach the ground through the two groups of exciting coils 52a, 52a and 52a, 52a that are arranged to face each other for driving the slides, and a closed circuit is formed. ing. In addition, power amplifier 136B, 136D
Both of the output sides of the above are connected to the ground through two groups of exciting coils 52b, 52b and 52b, 52b arranged to face each other for slide driving, and a closed circuit is formed.

Next, the operation of this embodiment will be described.

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

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

X equipped on the slide part 28B when the power is turned on
Directional distance sensors 42, 42 and Z-direction distance sensors 44, ..., 44
Is a displacement difference calculating means 72, 7 in each direction for calculating displacement signals dx and dz corresponding to the positions of the respective direction components from the guide member 28A.
Output to 2 and 78, ..., 78.

Here, the X direction control on the rear side will be described as an example. As described above, the X-direction displacement signal dx is a positive or negative displacement according to the direction in which the slide portion 28B is displaced from the reference position with respect to the guide member 28A and the amount thereof, as described above. It is converted into a difference signal Δdx and output to the X-direction magnetic bearing control means 74. Then, the displacement difference signal Δdx is processed in the X-direction magnetic bearing control means 74 as described above, and the positioning signals “V _slx + V _ix ” and “V _slx −V” are _{processed.
ix} ”is output to each of the power amplifiers 76A and 76B. These positioning signals “V _slx + V _ix ” and “V _slx −V _ix ” are multiplied by α by the power amplifiers 76A and 76B, respectively, and are applied to the exciting coils “50a + 50b” and “50a + 50b” in each column. The strength of the magnetic force is opposite on the left side and the right side via the guide member 28A.

For example, when the slide portion 28B is displaced from the reference position by θ in the plus X-axis direction (that is, displaced to the right side in FIG. 5), the displacement signal dx is larger than the reference signal V _sox. Therefore, Δdx and V _ix become negative values.
Therefore, “V _slx + V _ix ” becomes smaller than the value V _{slx at the} reference position, and conversely, “V _slx −V _ix ” becomes larger than the value V _{slx at the} reference position. Therefore, the left coil "50a
At "+ 50b", the attraction force to the guide member 28A is strengthened, and at the coil "50a + 50b" on the right side, the attraction force is weakened, so that the rear side of the slide portion 28B is returned to the left side in FIG.

On the contrary, when the rear side of the slide portion 28B is displaced from the reference position to the left side in FIG. 5, the displacement signal dx becomes smaller than the reference signal V _sox , and Δdx and V _ix are positive values. Becomes Therefore, “V _slx + V _ix ” becomes larger than the value V _{slx at the} reference position, and “V _slx −V _ix ” becomes smaller than the value V _{slx at the} reference position. The rear side of the portion 28B is returned to the right side.

Similarly, the position control described above is independently performed on the front side of the slide portion 28B, and its inclination is also corrected.

In this way, the slide portion 28B is held at the position where the magnetic forces are balanced, that is, the reference position. When positioned at this reference position, the displacement signal dx = reference signal V _sox , so the value V _ix obtained from the displacement signal dx becomes zero. For this reason, the excitation coil “50a + 50b” for the left and right bearings, ...
The positioning signals applied to each row at "50a + 50b" are equal to each other at _{.alpha.V slx} and balanced on both left and right sides, and the slide portion 28B is held at the reference position as it is.

By the way, the magnetic circuit by the electromagnets 36a, 36b and 36a, 36b for supporting in the X direction in the holding state at the above-mentioned reference position,
It is shown in FIG.

The electromagnets 36a, 36b and 36a, 36b are, as shown in FIG.
They are excited so that they have opposite polarities alternately. At this time, for example, the magnetic field line (see the dotted line in the figure) that has emerged from the N pole of the right electromagnet 36b passes through the rear portion 48K of the iron core 48 and enters the S pole of the adjacent electromagnet 36a. Then, the magnetic force lines emitted from the N pole of the electromagnet 36a are pole teeth a, ..., F, voids, protruding teeth 54, ..., 54 of the guide member 28A, guide member 28A, and again protruding teeth 54 ,. 54, the air gap, and the pole piece teeth a ′, ..., F ′ are sequentially returned to the S pole of the electromagnet 36b, thereby forming a closed magnetic circuit.

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

At this time, as described above, each pole piece tooth row 48Aa and 48Ba
, The phase is shifted by 1/2 pitch with respect to the protruding teeth 54, ..., 54, and the phase of each pole piece tooth row 48Aa is 1/80 with respect to 48Ba.
Because they are offset by 4 pitches, for example, at the positions shown in FIG. 8 (positions where the pole teeth a, c, e of the left and right electromagnets 36a and the phases of every two protruding teeth 54, 54, 54 match). It is stationary. In this way, the opposing electromagnets 36a, 36a and 36b, 3
The magnetic forces of the 6b are balanced (similar to other electromagnet pairs), and the slide portion 28B is held in the X direction in a non-contact manner.

Further, the operations of the front left to rear right magnetic bearings in the Z direction are 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 the displacement direction of the slide portion 28B with respect to the guide member 28A, the positioning signal α (V _slz + V _iz ) of an amount that corrects the displacement is obtained. It is formed. Then, the signal α (V _slz +
V _iz ) is set to be small or large so as to balance with the own weight of the slide portion 28B, the displacement of the slide portion 28B in the Z direction is corrected, and the slide portion 28B is returned to the reference position. At this time, since the positioning is independently performed at the four positions from the front left to the rear right, 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 is supported in the X, Y and Z directions in a non-contact manner and is accurately positioned at the predetermined reference position.

On the other hand, when the slide portion 28B deviates from its slide reference position due to a disturbance such as a load change in the slide drive or the like to be described later, this displacement state is detected by each sensor 42, 42, 44,
, 44 is immediately detected, and based on this, the same position correction operation as described above is executed. Therefore, the slide portion immediately returns to the original reference position.

Next, the slide driving operation will be described with reference to FIGS. 9 to 12. These figures show one of the basic groups described above.

First, in the state shown in FIG. 8 described above, when the slide drive signal V ₁ is simultaneously supplied from the slide drive control unit 30S to only the input terminals IN of the excitation coils 52a, 52a for slide drive on the left and right sides, Excitation current flows as shown in FIG.
At this time, the a, c, and e pole single teeth of both electromagnets 38a are
The magnetic force lines due to a and the magnetic force lines due to the electromagnet 38a are in the same direction, so that they are strengthened, and in the pole single teeth b, d, and f, they are offset or weakened because the magnetic force lines are in opposite directions. At this time, the adjacent electromagnets 38b, 38b are in the non-excited state, and the protruding teeth 54,
Focusing on any of the teeth in Fig. 9 in Fig. 9, this tooth is 1/4 of each pole piece tooth d'and d '.
It is on the pitch distance and the closest.

From the above-mentioned state, as shown in FIG. 10, the slide drive signal V ₂ is transferred to the coils 52b, at the falling edge of the slide drive signal V ₁ .
It is applied to only the input terminal IN of 52b at the same time. As a result, the magnetic force lines are strengthened by the electromagnets 38b at the pole single teeth b ', d', f'of the left and right electromagnets 38b, respectively.
Further, in the pole piece teeth of a ', c', and e ', the magnetic force lines are canceled or weakened. For this reason, the above-mentioned teeth and pole single teeth d ', d'
Are respectively sucked and reach the positions of the protruding teeth. That is, the entire slide portion 28B slides in the slide direction A by 1/4 pitch. At this time, the protruding teeth 54, ..., 54
Focusing on any other tooth in Fig. 10 in Fig. 10, this tooth is closest to the pole piece tooth f, f of both electromagnets 38a and is at a distance of 1/4 pitch.

Further, from the above-mentioned state, as shown in FIG. 11, the slide drive signal V ₃ is simultaneously applied again only to the input terminals IN of the coils 52a, 52a in synchronization with the fall of the slide drive signal V ₂ . As a result, both electromagnets 38a are excited in the opposite manner to that of FIG. 9 described above. Therefore, the pole single tooth f, f is the above-mentioned tooth,
Is attracted to the position of the tooth. That is, the entire slide portion 28B further slides in the slide direction A by 1/4 pitch. At this time, in both electromagnets 38b,
The tooth after, is closest to the pole piece teeth c ′ and c ′ at a distance of 1/4 pitch.

Furthermore, from the above state, as shown in FIG. 12, the slide drive signal V ₄ in synchronization with the rising of the slide drive signal V ₃
Is simultaneously applied only to the INs of the coils 52b and 52b. As a result, the electromagnets 38b on the left and right sides are excited in the opposite manner to the above-mentioned FIG. Therefore, the pole piece teeth c ′, c ′ are attracted to the position of the tooth by the magnetic force from the tooth. That is, the entire slide portion 28B is further moved in the slide direction A by 1
Slide by / 4 pitch.

In this manner, the slide operation of FIGS. 9 to 12 described above is repeated by repeatedly inputting the slide drive signals V _{1 to} V ₄ , and this operation is performed by the other group (2
The same applies to the electromagnets 38a, 38b, 38a, 38b of the set), so that the slide portion 28B slides substantially continuously in the slide direction A. At this time, the X-direction component of the attraction force due to the slide driving is canceled for each set on the left and right sides of the slide portion 28B, so that there is no influence that causes the above-mentioned magnetic bearing position change. Becomes Further, by shortening the repetition cycle of the slide drive signals V _{1 to} V ₄ , it is possible to slide at a higher speed.

As described above, the present embodiment has various advantages. First, since the slide driving force due to the magnetic force is applied to the slide portion 28B at positions symmetrically opposed to each other via the slide member 28A, the X-direction component of the slide driving force is canceled out, and the magnetic force associated with the slide is applied to the magnetic bearing position. Since the bearing position is not affected by the change, the slide portion 28B can be positioned with higher accuracy and can be slid at high speed. At the same time, since the suction drive is performed on both sides of the guide member 28A, a larger torque can be obtained as compared with the case where only one of them is used. Further, between the protruding tooth of the guide member 28A and the pole piece tooth of the slide portion 28B, the teeth whose phases match each other are always distributed on the left and right sides substantially evenly. The strain of the slide portion 28B can be further reduced as compared with the case where the teeth to be formed are local, which also promotes highly accurate position control and high speed drive of the slide portion 28B.

Further, excitation coils 52a, ..., 52a and 52b for slide driving,
, 52b are wound around the pole piece teeth a, ..., f and a ', ..., f'provided on the pole pieces 48A, ..., 48A, 48B, ..., 48B respectively, so that they are used for bearings. , 50a and 50b, ..., 50b form a closed magnetic path different from the closed magnetic path, so that the slide drive signal is different from the case where these magnetic paths are common.
Excitation coil 50a by V ₁ ~V _4, ..., 50a and 50b, ..., it is less of disturbing the magnetic bearing operation causes a counter electromotive force 50b, therefore, the repetition period of the signal V ₁ ~V ₄ The length can be shortened to allow high speed driving.

Further, the pole single teeth a, ..., F and a ′, ..., On the slide portion 28B side
Since f ′ is not simply a magnetic path and excitation coils 52a, ..., 52a and 52b, ..., 52b for slide driving are wound around this and are positively used, pole single teeth a, ..., f and , 52a and 52b, ..., 52b are wound at positions other than a ', ..., f', the entire drive unit 28 can be made smaller. ing.

Next, second and third embodiments will be described.

First, in the second embodiment, the slide drive signals V _{1 to} V are added to the slide drive start magnet in the above-described first embodiment even for the exciting coils 50a, ..., 50a and 50b ,. ₄ (both positive or negative pulse signal) is superimposed on the bearing signal and applied. According to this, the action and effect are equivalent to those of the above-described embodiment, and there is an 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 electromagnet for the magnetic bearing, and the slide driving coils 52a, ..., 52a and 52b, ..., 52b have the smallest possible inductance. It is a coil. According to this, in addition to the same effect as that of the first embodiment described above, the self-induced back electromotive force generated in the coil at the rise or fall of the slide drive signals V _{1 to} V ₄ is reduced, and the rigidity is further increased. Can be increased.

In each of the above-mentioned embodiments, the electromagnet for the magnetic bearing and the electromagnet for the slide drive are provided on the slide portion 28B side, but the present invention is not necessarily limited to this, and the guide member
May be equipped on the 28A side.

Further, in each of the above-described embodiments, 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.

〔The invention's effect〕

As described above, according to the present invention, in a state where the slide portion is supported in a non-contact manner, a magnetic force for driving the slide is simultaneously applied to the slide portion from the symmetrical position with respect to the slide portion, Since the slide portion is driven by repeating this with a plurality of groups, the orthogonal component of the driving force acting on the slide portion with respect to the slide direction is almost completely balanced, so that the slide position of the magnetic bearing changes, etc. It is possible to almost completely eliminate the situation that affects the magnetic bearing, which allows more accurate positioning in the sliding direction.
Since the closed magnetic path for the magnetic bearing and the closed magnetic path for the slide drive do not overlap each other, it is possible to avoid the situation where the magnetic path of the magnetic bearing is disturbed by the exciting current for the slide drive. Since switching to the excitation coil for slide drive can be performed at higher speed,
As compared with the prior art, the excellent effect of being able to obtain a direct-acting magnetic bearing motor that is smoother and travels at high speed is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a drive device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. 3 is III of FIG. -III is a cross-sectional view taken along the line III, FIG. 4 is a block diagram showing the controller of the first embodiment, FIG. 5 is a block diagram of the X-direction positioning portion in the controller of FIG. 4, and FIG. FIG. 4 is a block diagram of the Z direction positioning portion in the control device, FIG. 7 is a block diagram of the slide drive control portion in the control device of FIG. 4, and FIG. 8 is a part of a magnetic circuit in a magnetic bearing state. And FIG. 9 to FIG. 12 are explanatory diagrams for explaining the slide driving operation. In the figure, 28A is a guide member as a fixed guide portion, 28B is a slide portion, 30S is a slide drive control portion, 36, ..., 36 are electromagnets for X-direction support, 38, ..., 38 are electromagnets for slide drive,
40, ..., 40 are electromagnets for Z-direction support, 48A, ..., 48A, 48B,
..., 48B is a pole piece, 48Aa, ..., 48Aa, 48Ba, ..., 48Ba is a pole piece tooth row, 54, ..., 54 is a protruding tooth, 52a, ..., 52a, 52b, ..., 52b is an excitation for slide drive The coils a, ..., F, a ′, ..., F ′ are pole teeth.

Claims (1)

[Claims] 1. A slide part, and a fixed guide part which is disposed so as to face the slide part and guides the slide part.
A plurality of pairs of pole pieces are provided at equally spaced positions that are symmetrical to the other of either one of the fixed guide portion or the slide portion, and the magnetic pieces are attached to the respective pole pieces. In a direct acting magnetic bearing motor, each of which is provided with a bearing electromagnet so that the slide portion is slidably supported on the fixed guide portion in a non-contact manner, wherein either one of the slide portion or the fixed guide portion is provided. Of the pole pieces having a pitch different from that of the projecting teeth on the side of the plurality of pairs of pole pieces facing the projecting teeth. Each of the pole piece tooth rows is provided, and one of the plurality of pairs of pole piece tooth rows is arranged with a predetermined phase shift with respect to the other adjacent pair, and the pole piece tooth rows of the plurality of pairs are arranged. For one tooth, adjacent poles have opposite polarities. Each of the plurality of sets of exciting coils is wound so as to be excited by a pair, and a slide drive for supplying the same amount of exciting current to each set of exciting coils that is symmetrical with respect to the slide part or the fixed guide part at the same time. A direct-acting magnetic bearing motor having a control unit.