WO1982000389A1

WO1982000389A1 - Electrodynamic driving device

Info

Publication number: WO1982000389A1
Application number: PCT/DE1980/000101
Authority: WO
Inventors: G Schmidt
Original assignee: G Schmidt
Priority date: 1980-07-11
Filing date: 1980-07-11
Publication date: 1982-02-04
Also published as: EP0055703A1

Abstract

Electrodynamic driving device for the control of displacements of a moving member (18) from a determined point of a plane of a coordinate system to another given point. The moving member (18) has at least two conducting non-parallel tracks (19, 20, respectively 21, 22); it is displaceable within a plane, in a magnetic field. The magnetic field forms a network and has areas (24, 25) of different indication of the magnetization direction. Between the areas of the magnetic network are areas substantially deprived of any field. Further, a control device supplies the conducting tracks (19, 20, 21, 22) of the moving member (18) with current pulses. The electrodynamic driving device may be used for example for a writing device or as a reading device in an electronic memory. Owing to the low weight of the moving parts, a particularly high working speed may be reached.

Description

"Electrodynamic drive"

The invention relates to an electrodynamic drive for controlling movements of a rotor device from any coordinate point on a plane to any other.

In very different areas of research and technology, there is the problem of moving a runner device connected to observation, recording and writing instruments in one plane in a defined manner. One has to think of recording devices for two different measured quantities that are to be plotted as a function of one another, so-called XY recorders, magnetic heads for reading magnetic data stored on flat information carriers, and observation devices for tracking events at specific points on the observation area of nuclear bubble chambers. The basic meaning of such a drive is already clear from these few, from a large number of further selected application examples. Despite the variety of possible applications, the requirements for such a drive are essentially always the same. The main focus here is on a high working area Speed, ie a fast working control and high acceleration and braking values of the rotor device. Of course, the costs should be kept within reasonable limits. It follows from both of the above requirements that complicated mechanical parts should largely be dispensed with in the construction of the drive.

However, the previously known drive devices do not meet the last requirement. In addition, they often require complex power electronics. Finally, the known drive devices can only be controlled by analog signals, but this is a major deficiency with regard to the computer control that is increasingly intervening in all areas of technology

The invention has for its object to avoid the aforementioned Nac parts of the known prior art and to create an electrodynamic drive, which is characterized above all by high control and adjustment speed and easy adaptability to the respective application.

This object is achieved according to the invention in an electrodynamic drive of the type mentioned at the beginning by means of at least two conductor tracks which are not parallel to one another and which have a magnetic field in a grid-like manner, grid areas with different signs of the magnetization direction, in a plane movably mounted rotor device, the conductor tracks being controlled by a control device be supplied with current or current pulses.

In contrast to previously known comparable devices, each using a separate servomotor, for example a disk motor, for movement in the X or Y direction an integral electrodynamic drive is provided in the design according to the invention. The defined rest positions of the rotor device, predetermined by the grid-like structure of the magnetic field, enable direct digital control of the arrangement. Since the rotor device itself no magnets or iron cores or mechanical components such as gears, wire guides or the like. needs to be carried, it can be easily built accordingly and accelerated very strongly with forces that can be generated by electrodynamic means. The movement of the rotor device takes place on the basis of the electro-mechanical principle known per se, according to which a force acts on a current-carrying conductor in a magnetic field with a component perpendicular to the current direction, which force in turn is directed perpendicular to the current and the magnetic field component. Accordingly, the rotor device moves in a plane perpendicular to the magnetic field. The direction of movement is determined by the longitudinal direction of the current paths and the orientation of the current or the magnetic field. The direction of movement of the rotor device can thus be controlled in particular by changing the direction of the current flowing through the conductor tracks.

It is particularly advantageously provided that the rotor device comprises two sets of mutually parallel sets of interconnects which are each parallel and not connected to one another. From the principle set out above, known as the so-called "three-finger rule", this means that movements are possible with both X and Y components, the force in the being due to the mutually parallel, series-connected conductor tracks respective direction is multiplied according to the number of conductor tracks. The invention is preferably implemented in such a way that the center points of the raster areas of the magnetic field correspond to points of a Cartesian coordinate system, two magnetized raster areas that are adjacent along the coordinate axes each have the same and diagonally adjacent different magnetization devices, and one that is at least relatively equivalent to three times the width of the magnetized areas field-free area are separated and the rotor device comprises two mutually perpendicular groups of conductor paths, each group consisting of two subgroups of mutually parallel conductor paths that can be controlled individually by the control device, the conductor paths of each subgroup being connected in series and the conductor paths being arranged in such a way that one Conductor path of one subgroup follows one of the other and the distance between them corresponds to the width of a grid area.

With this arrangement, the rotor device can be directed to any coordinate points of a Cartesian coordinate system by appropriately controlling the current flow in the individual conductor tracks. The division of the conductor tracks in each coordinate direction into two sub-groups, of which the conductor tracks of a sub-group cross each other due to the selected arrangement of the grid areas, while the conductor tracks of the other sub-group run in the at least relatively field-free area, enables the rotor device, for example, by a current pulse to move one grid step in the X or Y direction. The end positions achieved thereby represent equilibrium positions and are therefore clearly defined. With another surge of electricity after its polarity, the movement in the original direction can be continued by a further step or reversed again. From this it can already be seen that the electrodynamic drive according to the invention results in a large number of application variants, in particular in connection with a computer control.

To generate a grid-like magnetic field it can be provided that above and below the plane of the rotor device a plate-like arrangement of rod-shaped, cross-sectionally rectangular permanent magnets and interposed, soft iron pieces of the same shape is provided, that the magnetization direction of the magnets is perpendicular to their longitudinal direction in the plane of the plate, that the magnetization direction of adjacent magnets is opposite to each other, and that the longitudinal direction of the magnets above and below the rotor device is offset by 90 °. By superimposing the individual magnetic fields of the magnets assembled in this way, a grid-like magnetic field in the sense of the invention is created in the area between the two plate-like arrangements, high field densities being thereby achieved.

Another possibility for generating such a field is that a plurality of coils is arranged in a plane above and below the plane of the rotor device, the longitudinal axis of which is perpendicular to this plane, which are switched according to the winding sense or current direction so that the Signs of the direction of magnetization in one plane along the coordinate axes of adjacent coils are the same and diagonally adjacent coils are different and are the same as those above or below in the other plane, the coils of each level being spaced three times the width of the coils. This arrangement If desired, it also enables the magnetic field, that is to say the current flowing through the coils, to be used for control purposes.

Advantageously, the rotor device consists of a plate of insulating material laminated on both sides with a printed circuit board, the conductor tracks in the printed circuit boards being formed by etching. Such plates, as they are already used with great success in a comparable form in the disc rotor motor, can be built extremely light with a weight of a few grams, so that according to Newton a very high acceleration is achieved from the available electrodynamic force. The conductor tracks are preferably flat, so that very good heat radiation is achieved, which allows a very considerable, very short-term current load of up to 10 A. This is another reason for the high working speeds that can be achieved with the arrangement according to the invention. In principle, various more modern methods for producing so-called multi-layer plates for the runner device are conceivable.

In a further embodiment of the invention it is provided that the rotor device is mounted on slot ball bearings, which in turn are seated on slot ball bearings perpendicular to this. Such bearings, which are known per se in precision engineering, ensure extremely low friction with reliable, play-free guidance.

To control the rotor device, a digital control device with actual-target-value control is particularly advantageously provided. The particular suitability of the drive according to the invention for digital controls has already been explained. Thus, an actual-target-value comparison can be made via an electronic displacement transducer using a computer circuit take and thus achieve an exact positioning. For example, the actual value can be taken from the local change in the magnetic field.

From the various methods for digital control of movement processes familiar to the person skilled in the art, e.g. a digital positioning system according to Commischau and Hangarter, especially for controlling the runner equipment. This system (cf. "Electronics" (Franzis-Verlag), issue 4/70, p. 5), which was originally used to position a

Cross table was developed by means of two disc rotor motors, can be transferred to the drive according to the invention in an analogous manner.

The area of conceivable application is further expanded by the fact that the rotor device and the associated magnet devices are connected to a second rotor device, the plane of movement of the second rotor device being perpendicular to that of the first.

The electrodynamic drive according to the invention can be used particularly advantageously, for example, in typewriters. In the case of a computer-controlled runner device according to the invention, the size and shape of the characters can be changed simply by corresponding reprogramming of the computer, the number of characters in a specific program being considerably larger than that in conventional mechanical typewriters, so that it would be conceivable to use such a type Typewriter, for example, to write Chinese characters. In addition, such a typewriter would also be particularly suitable as a so-called typewriter, ie entire parts of a letter could be easily stored and called up. Furthermore, a large number of mechanical, fault-prone parts would be used in this new typewriter type are eliminated, but this machine would also work practically noiselessly.

On the other hand, the use of the drive according to the invention can also be very advantageous for magnetic recording and playback devices, since rotating parts can be dispensed with and flat data carriers can be used. Extremely short access times can be achieved with a high storage capacity. A very extraordinary high storage capacity is achieved especially when two drive systems according to the invention are arranged perpendicular to one another, so that the data carriers can be arranged three-dimensionally and called up in a very short time.

When using the drive according to the invention for recorders, so-called plotters, the use of digital-to-analog converters can be dispensed with when using digital measuring instruments, so that the resulting problems are eliminated.

Further features, details and advantages of the invention will become apparent from the following description of a preferred embodiment and from the drawing. Show:

1 to 3 are schematic representations of permanent magnet soft iron arrangements for demonstrating the formation of the grid-shaped magnetic field according to the invention, FIG. 4 is a schematic representation of two plate-shaped permanent magnet soft iron arrangements according to the invention, FIG. To explain the formation of the grid-shaped magnetic field according to the invention, the case is first shown in FIG. 1 that between two superimposed, cuboid-shaped soft iron pieces 1, 2 or 3, respectively, two likewise rectangular permanent magnets 5, 6 with a shorter side length than the soft iron pieces 1 , 2,3,4, on the top and bottom are arranged flush with these between them. The permanent magnets 5, 6 are magnetized in the direction parallel to the shortest side edge and are arranged so that the magnetization directions of the upper and lower permanent magnets 5, 6 in FIG. 1 are opposite to each other. Together with the soft iron pieces 1, 2, 3, 4 there is a closed field line course from the south pole S of the upper permanent magnet 6 to the north pole N of the lower permanent magnet 5 and from its south pole S to the north pole N of the upper permanent magnet 6.

If the two upper pieces of soft iron 3, 4 are rotated by 90 together with the upper permanent magnet 6 lying between them, field areas with oppositely oriented magnetic field lines come to lie directly one above the other, ie the resulting field becomes practically 0. As can be seen from FIGS. 2 and 3, which each represent the situation in the case of a rotation by 90 in a clockwise or counterclockwise direction, give rise to field-free regions 7, 8 corresponding to the width of the soft iron pieces 1, 2, 3, 4, and likewise field-free regions 9 corresponding to the width of the permanent magnets. 10 are separated from regions 11, 12 of the soft iron pieces 1, 2, 3, 4, where they magnetize approximately perpendicular to the original magnetization direction of the permanent magnets 5, 6 in the direction of the other two soft iron pieces 1, 2 and 3, 4 above and below , the two resulting, diagonally opposite magnetized regions 11, 12 opposing each other t are magnetized in parallel. Based on the thinking model described above, it is understandable that a raster-shaped magnetic field arises when two plate-shaped arrangements 15, 16 consisting of parallelepiped-shaped permanent magnets 13 and soft iron parts 14 are arranged one above the other with their longitudinal axis rotated by 90 °, as shown in FIG. 4 . A piece of soft iron 14 is followed by a permanent magnet 13, the direction of magnetization of which lies in the plane of the plate 15, 16 to be built, this in turn is a piece of soft iron 14, then again a permanent magnet 13, the direction of magnetization of which is also in the direction of the plane of the plate, but that of the previous one Permanent magnet 13 is opposite, then again a piece of soft iron 14, etc.

Between the two magnetic soft iron plates 15, 16 there remains a gap 17 which is just dimensioned such that free and unimpeded movement of the rotor device 18, which is mounted in a plane which is easily XY-movable on bearings not shown in the drawing, is made possible. The runner 18 is e.g. from a Pertinax or carbon fiber plate 18 'which is laminated on both sides with copper plates, the conductor tracks 19, 20, 21, 22 being etched out of these copper plates. Each conductor track 19, 20, 21, 22 belongs to a meandering subgroup of

Conductor tracks 19 or 20 or 21 or 22 on. The conductor tracks 19, 20 and 21, 22 on the top and bottom of the rotor plate 18 'run perpendicular to one another. On each side of the rotor plate, the conductor tracks 19, 20, 21, 22 form two subgroups, which consist of two superimposed on each other

Half of the mutual conductor spacing between mutually displaced meandering arrangements exist. The individual conductor tracks 19, 20 and 21, 22 of each subgroup run parallel to one another and only at the edge region of the rotor plate 18 'are adjacent conductor tracks 19, 20, 21, 22 that are the same Belong to subgroup, connected. The insulating bridging of the intersecting ends of the individual conductor tracks 19, 20, 21, 22 of the different groups, which is not shown in detail in the drawing, can be carried out in a manner known per se from the art of printed circuits. The mutual distance d of the individual parallel conductor tracks 19 or 20 or 21 or 22 of each subgroup corresponds to twice the width b of the magnet or soft iron blocks 13, 14. Both subgroups of the upper and lower conductor tracks 19, 20 and 21, 22 are each individually connected to a power supply device which can produce the "current" and "no current" state independently of one another in each of the two upper and lower conductor subgroups. The sign of the current direction can be selected for the "Current" state.

The soft iron magnetic plates 15, 16, which are rotated 90 ° relative to one another, generate a grid-shaped magnetic field in the gap 17 between them. This magnetic field is made up of individual areas 23, 24, 25, the edge length of which corresponds to the width b of the magnet or soft iron pieces 13 or 14. In the direction of the X and Y coordinates, each magnetized area 24, 25 is separated from the next by three field-free areas 23. Adjacent magnetized areas 24 and 25 have the same sign of the direction of magnetization. In the starting position lies the rotor plate 18 ', which together with a writing device 26 attached to it, for example, which is only shown schematically in FIG. 5, forms the rotor device 18 such that the conductor tracks 19, 20 or 21, 22 of the upper or lower sub-groups lie in the X or Y direction specified by the edges of the magnetic soft iron plates 15, 16. The crossing points 27 of the upper and lower current paths 19, 20 and 21, 22 each lie in the middle of the areas 23, 24, 25. 5 a - f illustrate how a desired two-dimensional movement of the rotor device 18 can be achieved by a sequence of current pulses on a specific subgroup of conductor tracks 19, 20, 21, 22. The current state of the individual conductor track groups is represented by arrows P, the presence of an arrow P meaning that this conductor group is acted upon by a current pulse and the direction of the arrow indicates the direction of the respective current pulse. The unfilled areas are relatively field-free areas 23; in the magnetic areas 24, 25 the direction of the magnetic field in FIG. 5 is indicated by dots or crosses as out of the plane of the drawing. illustrated in the drawing plane. The direction of movement of the rotor device results in each case as the sum of the force effect in the X and Y directions, the direction of force, that is to say its sign, being determined in a coordinate direction from the three-finger rule, according to which at X, Y and Z are mutually perpendicular - Direction held thumb, index finger and middle finger, the thumb the direction of the magnetic field (Z direction), the index finger (X or Y direction) the direction of the current and the middle finger the direction of the force (X or Y direction ) indicates.

With each current pulse, a movement is achieved by, for example, an area width b in the X or Y direction, the end position being defined and further movement beyond this end position being avoided by the current being then applied to the next parallel conductor track, for example 19 Subgroup would cover magnetic field areas 24 and 25, respectively, which have a different orientation than those which gave rise to the original movement, but which, according to the three-finger rule, directly results in a force which is opposite to the original force. In order to continue the movement in the same direction by a further step, the conductor tracks, for example 20, must be each other subgroup receive a current pulse in the opposite direction. The two subgroups on each side of the plate therefore receive alternating current pulses for the movement along a coordinate axis, the direction of movement being determined by the current direction of these pulses. However, the control can also be carried out in small steps as those corresponding to the grid.

In principle, it is also conceivable for certain application purposes to arrange different rotor devices one above the other in parallel.

Finally, it is also conceivable, as a runner device, not a rigid disk, but a flexible belt or the like. to use.

Claims

Claims:

1. Electrodynamic drive for controlling movements of a rotor device from any coordinate point on one plane to any other, characterized by an at least two non-parallel conductor tracks (19, 20 or 21, 22) carrying in a grid-like, grid areas (24 , 25) with a different sign of the magnetization direction magnetic field in a plane movably mounted rotor device (18), the conductor tracks (19, 20, 21, 22) being supplied with current or current pulses by a control device.

2. Electrodynamic drive according to claim 1, characterized in that the rotor device (18) comprises two mutually non-parallel groups of mutually parallel, series-connected conductor tracks (19, 20 or 21, 22).

3. Electrodynamic drive according to claim 1 or 2, characterized in that the center points M of the grid areas (24, 25) correspond to the points of a Cartesian coordinate system, two along the coordinate axes X, Y each adjacent, magnetized grid areas (24, 25) the same and diagonally adjacent areas (24, 25) have different magnetization directions and are separated by an area (23) which is at least relatively field-free and corresponds to at least three times the width b of the magnetized areas (24, 25) and the rotor device (18) has two mutually perpendicular groups of conductor tracks (19,20,21,22), each group consisting of two subgroups parallel to each other, individually controllable by the control device conductor tracks (19,20 and 21,22), the conductors tracks (19, 20, 21, 22) of each subgroup are connected in series and the conductor tracks (19, 20, 21, 22) are arranged in such a way that each one (21, 22nd) ) follows the other and their mutual distance corresponds to the width b of a grid area (23, 24, 25).

4. Electrodynamic drive according to claim 3, characterized gekennzeiohnet that above and below the plane of the rotor device (18) a plate arrangement (15, 16) of rod-shaped, cross-sectionally rectangular permanent magnets (13) and intervening, identical soft iron pieces (14) are provided is that the magnetization direction of the magnets (13) is perpendicular to their longitudinal direction in the plane of the plate, that the magnetization direction of adjacent magnets is opposite to each other, and that the longitudinal direction of the magnets (13) above and below the rotor device (18) by 90 ° to each other is offset.

5. Electrodynamic drive according to claim 3, characterized in that a plurality of coils is arranged in a plane above and below the plane of the rotor device (18), the longitudinal axis of which is in each case perpendicular to this plane, which are switched according to the winding sense or current direction that the signs of the direction of magnetization in each case in one plane along the coordinate axes X, Y of adjacent coils are the same and diagonally adjacent coils are different, and those in the other plane below or above are the same, the coils of each plane being different from one another three times the coil width are spaced.

6. Electrodynamic drive according to one of claims 1 to 5, characterized in that the rotor device (18) consists of a plate laminated on both sides with a printed circuit board (18 ') be made of insulating material, the conductor tracks (19,20,21,22) are formed in the circuit boards by etching.

7. Electrodynamic drive according to claim 6, characterized in that the rotor device (18) is mounted on slot ball bearings, which in turn are seated on slot ball bearings perpendicular thereto.

8. Electrodynamic drive according to one of claims 1 to 7, characterized in that a digital control device with actual-target value control is provided for controlling the rotor device (18).

9. Electrodynamic drive according to claim 8, characterized in that a programmable digital positioning system according to Commischau and Hangarter is provided for controlling the rotor device (18).

10. Electrodynamic drive according to one of claims 1 to 9, characterized in that the Läufsrsinrich device (18) and the associated magnet devices are connected to a second rotor device, the plane of movement of the second rotor device being perpendicular to that of the first.