WO2009132729A2

WO2009132729A2 - Industrial device comprising a multiphase linear motor that can be equipped with several movable units

Info

Publication number: WO2009132729A2
Application number: PCT/EP2009/001717
Authority: WO
Inventors: Stephane Pellegrini
Original assignee: Etel S.A.
Priority date: 2008-04-30
Filing date: 2009-03-11
Publication date: 2009-11-05
Also published as: WO2009132729A3

Abstract

The invention relates to an industrial device comprising a multiphase linear motor (22) whose movable units (32) have a plurality of windings (38, 39, 40) which are all disposed with their respective centers (42, 43, 44) substantially in a same plane (46) perpendicular to the direction of displacement X of the movable part. In order to maintain the electromagnetic phase shift between the different phases of the motor, the permanent magnets (6) of the magnetic track (24) are arranged such that each winding associated to a different phase is magnetically offset in relation to the other windings associated to the other phases of the linear motor. In particular, three lines or rows of magnets (28, 29, 30) are provided, which are associated to the three respective windings defining the three phases of the three-phase motor, wherein each row is offset by +/- 120° in relation to the two other rows. In one variant, the rows are offset by 60°.

Description

Industrial equipment with a multiphase linear motor equipped with several movable units

The present invention relates to an industrial device, in particular with a polyphase linear motor, which can be equipped along its magnetic track with a plurality of movable units. The magnetic track has permanent magnets, which are arranged in the direction of displacement of the movable units of alternating polarity. Each movable unit includes a plurality of windings arranged to respectively define a different phase of a polyphase linear motor formed of this movable unit and the magnetic track. It should be noted that any of a linear motor may be mentioned here, which may be equipped with a plurality of movable units or with a plurality of linear motors, which are assigned to the plurality of movable units, which share a same magnetic track.

In general, such a linear motor is incorporated in an industrial device which is intended to dispose a plurality of tools that are adjustable in a given direction of displacement. For this purpose, each tool is associated with a movable unit which can be electrically operated above a magnetic track, which is formed from a plurality of magnets.

It should be noted that in addition to the movement in the displacement direction of the movable units, each movable unit may be provided with an auxiliary motor with which a part of this movable unit in another direction or along a further axis of the device, in particular perpendicular to said displacement direction can be actuated , The arrangement of a conventional linear motor is shown schematically in Figures 1 and 2. The linear motor 2 includes a magnetic track 4, the a plurality of permanent magnets 6 is formed, which are arranged with alternating polarity. The magnetic period P is defined by a pair of reverse polarity magnets. The movable part of the linear motor is shown in a simplified manner only partially with three windings 10, 11 and 12. These three windings define three respective phases P1, P2 and P3. In general, the windings are connected in a star-shaped configuration with the three windings having a common end to form a neutral point. They can also be connected in a triangular configuration. The movable part is displaced along the displacement axis X. The windings 11 and 12 are, for example, phase-shifted by-300 ° or + 300 ° with respect to the winding 10, which corresponds to a phase shift of +/- 60 °. By reversing the direction of current flow in the winding 10 with respect to the windings 11 and 12, there is finally an electromagnetic displacement of +/- 120 ° between one winding and the other two windings of the moving part.

The type of engine considered is tooth-free. The windings may or may not have a magnetic core. It is also possible to arrange a closing plate for closing the magnetic flux over the windings 10, 11 and 12. Other arrangements may be provided by those skilled in the art while maintaining the 120 ° shift between the phases of the three-phase linear motor.

The arrangement of three windings associated with the three respective phases of the linear motor along the displacement axis X results in the movable member having a dimension L along this displacement axis which is relatively large and extends generally above a plurality of magnets of the magnetic track. This leads to a significant disadvantage: namely, it limits the number of movable units that can be arranged on a magnetic track of a certain length. The moving parts of a linear motor from the state of Technology are thus relatively space consuming due to the orientation of the windings along the displacement axis X.

The object of the present invention is to eliminate this significant disadvantage by reducing the dimension of the movable unit in its direction of displacement X, so that a magnetic track of a given length can be assigned a larger number of such mobile units and thus the center axes of two adjacent ones. Zender units can be approximated, which are movably mounted in an industrial device according to the invention. It should be noted that the tool mounted on a movable unit is preferably arranged in its central axis. The aim of the invention is also to allow a tool to be operated at a short distance from another tool, which is arranged on an adjacent moving part. To this end, the present invention relates to an industrial device having at least one movable unit, which is movable in a displacement direction of said at least one movable unit, and having a magnetic track with permanent magnets, which are arranged in the direction of displacement of alternating polarity, these magnets a main plane of the magnetic track define. Each movable unit includes a plurality of windings arranged to respectively define a different phase of a polyphase linear motor formed of this movable unit and the magnetic track. This device is characterized in that the plurality of windings with their respective center point are all substantially in a same plane perpendicular to the direction of displacement and that the permanent magnets of the magnetic track are arranged such that each winding of the plurality of windings with respect to the further windings thereof A plurality of windings is magnetically offset to define different phases of the polyphase linear motor ren. - A -

According to a preferred embodiment, the industrial device according to the invention is characterized in that the plurality of windings are substantially equidistant from the magnetic track and arranged successively in a direction perpendicular to the direction of displacement of the movable part and parallel to the main plane of the magnetic track.

Due to the features of the industrial device according to the invention, the moving parts may have a dimension in the displacement direction X which is substantially equal to the width of a single winding, since the centers of the windings defining the phases of the motor are no longer aligned in the displacement axis, but in lie substantially in a plane perpendicular to this direction X. Thus, in a multi-phase linear motor, instead of a dimension in the displacement axis which is at least equal to the sum of the widths of the windings, each movable part may according to the invention have a dimension in this displacement axis X corresponding to the width of a single winding. By changing the arrangement of the windings and the magnets of the magnetic track, a significant reduction in the space requirement of each movable along the displacement axis X part is thus achieved.

A more detailed explanation of the industrial device according to the invention will become apparent from the following description, which refers to the accompanying drawings, given by way of non-limiting example, in which: Figure 1, already described, schematically illustrates a linear motor of the prior art .

FIG. 2 shows a sectional view along the line H-II from FIG. 1,

FIG. 3 partially shows the linear motor of a first embodiment of an industrial device according to the invention, FIG. 4 shows a schematic, perspective view of the first embodiment of the industrial device,

FIG. 5 shows a variant of the first embodiment of the invention,

6 shows a partial view of the linear motor in elevation according to a second embodiment of an industrial device according to the invention,

FIG. 7 shows a variant of the linear motor according to FIG. 6,

8 shows a partial view of the linear motor in elevation according to a third embodiment of an industrial device according to the invention, and FIG. 9 shows a partial view of the linear motor in elevation according to a fourth embodiment of an industrial device according to the invention.

With reference to Figures 3 and 4, a first embodiment of an industrial device according to the invention will now be described. In particular, the linear motor 22 of the industrial device 20 will be described, which is illustrated schematically and in perspective in FIG. This motor 22 includes a plurality of magnets 6 forming a magnetic track 24. This plurality of magnets 6 is arranged in a same main plane X-Z of the engine. These magnets are arranged on a carrier 26, which forms the frame of the industrial device 20. According to the invention, in this first embodiment, three pluralities of magnets 28, 29, 30 are provided which form three respective rows of magnets which are parallel, the magnets of each plurality of magnets being arranged in alternating polarity. The three rows of magnets oppose three respective windings 38, 39, 40 of the movable unit 32 (as well as the moving parts 34 and 36, which are also attached to the magnetic track 24). These three windings define three phases of the three-phase linear motor 22 so that each plurality of magnets 28-30 is associated with a different phase of the motor.

The movable unit 32 (or each of the other movable units 34 and 36) includes a plurality of windings 38, 39 and 40, the like are arranged to each define a different phase of the three-phase linear motor 22. According to the invention, in the case of this plurality of windings, these with their respective center points 42, 43, 44 are all substantially in the same plane 46 perpendicular to the direction of displacement X of the movable unit. In particular, in this first embodiment, the plurality of windings are arranged in succession in the direction Z, which runs parallel to the main plane XZ of the magnetic track 24.

According to the invention, the permanent magnets 6 of the magnetic track are arranged such that each winding 38 to 40 is magnetically offset with respect to the other two windings of this plurality of windings on the magnetic track to define the different phases of the three-phase linear motor. For this purpose, the magnets of each magnetic line 28 to 30 with respect to the other two magnetic lines in the displacement direction X are magnetically offset or phase-shifted. In order to achieve an electromagnetic phase shift of 120 ° between the three phases of the motor 22, in the variant illustrated in FIG. 3, the magnetic lines 29 and 30 are + 120 ° or -120 ° relative to the central magnetic line 28 (FIG. equal + 240 °) magnetically. Since the three windings are aligned in the direction Z perpendicular to the displacement direction Y, each winding has a phase shift of +/- 120 ° with respect to the other two windings, when the current flows in these windings in the same direction as in the in FIG variant shown is the case. In this figure 3 it should be noted that the arrangement of the magnetic lines thus takes place such that the respective centers of the two magnets of the same polarity, which belong to the two respective magnetic lines 28 and 29, have a magnetic offset by 120 °. The magnetic offset between the respective centers of the two magnets of the same polarity, which belong to the respective magnetic lines 28 and 30, is - 120 °. Conventionally, the movable units are supported on two rails 48 and 49. Each movable unit includes a sensor 50 for Measuring the displacement of the movable unit in the displacement direction X, which sensor is associated with a scale 52 which is arranged on the side of the rail 49. The three windings are electrically arranged in a star-shaped configuration with their first ends joined together while their second ends form the three phases P1, P2 and P3 of the linear motor. The three windings may also be arranged electrically in a triangular configuration.

In general, the magnetic track of the linear motor according to the invention comprises at least two pluralities of permanent magnets of alternating polarity associated with two respective different phases of each mobile unit. These two pluralities of magnets form two respective magnetic lines or rows that are parallel and face two respective windings of the plurality of windings associated with these two respective phases. The variant with only two pluralities of permanent magnets associated with two respective different phases of each mobile unit relates to the case of a two-phase linear motor. Care is taken to arrange the two rows of magnets so that a magnetic phase shift of 90 ° between the phases of the motor is achieved. In the variant shown in Figure 3, the centers of the three windings are aligned exactly along the axis Z. It should be understood, however, that the invention is not limited to this preferred configuration, but that a certain offset between the centers of the windings along the displacement axis X may be provided in less advantageous embodiments, with the magnetic displacements between the respective magnetic lines being selected in that a phase shift of 120 ° is maintained between the phases of the three-phase motor. Such variations do not depart from the scope of the present invention and, insofar as these displacements remain largely under a magnetic phase shift of 120 °, are defined by the term "all substantially in a same plane perpendicular to the direction of displacement "to understand.

In Figure 4, each movable unit 32 or 34 and 36 is formed of a lower part 72, in which the windings 38, 39 and 40 are arranged, as well as of an upper part 74, in which a motor module is arranged, which is intended to a Displacement of this part or an element 74 belonging to this element in the direction Z perpendicular to the direction of displacement X to allow. In particular, it is provided to be able to displace the tool holder 76 associated with each movable unit along the axis Z. These tool holders define the center axes 78 of the respective movable units. Due to the invention, the dimension of the movable unit in the displacement direction X is relatively small, i. H. significantly lower than that which results in a conventional linear motor. Thus, the two central axes 78 of two adjacent movable units 34 and 36 can be approximated to a relatively small distance D, whereby the two tools which are mounted on the two movable units 34 and 36, respectively, operate side by side in a relatively short distance can. In a more complex variant, it is also possible to provide a movement of a part of the movable units along the axis Y perpendicular to the main plane of the magnetic track. It is thus to be noted that it is possible with the present invention to place on a given magnetic track of certain length a number of movable units which is significantly higher than the number possible with the prior art motor shown in Figs. 1 and 2 ,

FIG. 5 shows a variant of the first embodiment described above. The above-described reference numerals will not be described again in detail here. The linear motor 56 differs from the linear motor 22 of FIG. 3 in that the mean magnetic line 28, which is assigned to the winding 38 defining the first phase P1 of the motor, is rotated by 180 ° relative to this motor 22. is netted. In order to maintain a 120 ° offset between the three phases of the motor 56, the current in the central winding 38 of the movable unit 32A has been reversed so that the electromagnetic phase of the first phase is identical for the two variants of FIGS. 3 and 5, respectively is.

FIG. 6 schematically shows a second embodiment of an industrial device according to the invention. In particular, FIG. 6 shows the linear motor 60 of the industrial device according to this second embodiment. The elements with the above-described reference symbols will not be described again here.

This second embodiment differs from the first embodiment essentially in that the magnetically offset rows of magnets have been replaced by a plurality of magnets 62, which are arranged obliquely to the displacement direction X or equivalently obliquely to the plane 46 which is perpendicular to this displacement direction , According to the invention, the orientation of these oblique magnets 62 is defined such that in the case of the plurality of windings 38, 39 and 40 they are magnetically offset relative to one another in order to define the different phases of the linear motor 60. In the variant in FIG. 6, in which the several windings are arranged with a current flowing in the same direction (which corresponds to the case from FIG. 3), the oblique magnets 62 have a longitudinal axis 64 which is aligned such that the two points 66 and 68 of this axis, which are aligned with the two centers 43 and 44 of the two outer windings 39 and 40 in the displacement direction X, have a magnetic offset of +/- 120 ° with respect to the point 70 of this longitudinal axis 64 having the center 42nd the middle winding 38 is aligned. Overall, the three windings thus have an offset of 120 ° to each other.

FIG. 7 shows a variant of the second embodiment. In this variant, the movable unit is similar to the

Variation of Figure 5 arranged. The direction of the current of the middle Winding 38 is opposite to the direction of the current in the two outer windings 39 and 40. As explained in the variant illustrated in FIG. 5, the arrangement of the windings of the movable unit 32A makes it possible to arrange the magnetic parts associated with the two outer windings 39 and 40 with an offset of 60 ° with respect to the magnetic part associated with the central winding 38 , Thus, in this variant, the longitudinal axis 76 of the oblique magnets 74 of the linear motor 72 at an angle relative to the direction Z, which is less than the corresponding angle of the variant shown in Figure 6. The offset between the center 70 of the longitudinal axis 76 and the two points 66 and 68, which are aligned with the two centers 43 and 44 of the two outer windings in the direction X is equal to +/- 60 °. This variant is advantageous because the fluctuation of the magnetic flux over the length of a winding is smaller. FIG. 8 schematically shows the linear motor 80 of a third embodiment of an industrial device according to the invention. This third embodiment aims to solve a problem in the previous embodiments. Namely, the arrangement of the windings in a direction perpendicular to the direction of displacement results in the two outer windings 39 and 40 having a resultant force exerted on the movable unit 32 not perpendicular to the center of gravity of the first and second embodiments moving unit is located. This has the consequence that the electromagnetic force of the two corresponding phases generates a certain torque in a plane parallel to the main plane XZ of the magnetic track. This torque must be compensated mechanically by the device of the mobile unit associated with the displacement rail of this mobile unit. In certain cases and in certain applications, this can be a problem that is effectively solved with the third embodiment below. The linear motor 80 is a three-phase motor whose movable portion 82 includes a first plurality of windings 38, 39 and 40A associated with the three respective phases of the motor. This movable part 82 further includes a second plurality of further windings 84 and 86 associated with two respective phases of the motor. The first plurality of windings is associated with three magnetic lines 28, 29 and 30A. It should be noted that the magnetic line 30A is formed of magnets 6A having a length substantially equal to twice the length of the magnets 6 forming the two lines 28 and 29. The doubling of the length of the magnets 6A can be achieved with magnets of different sizes or by the juxtaposition of two standard sized magnets 6. The magnetic track 24A further includes two magnetic lines or rows 88 and 89, which are associated with the two further windings 84 and 86, respectively. In order that the resultant force exerted on the movable unit 82 by each phase always remains substantially in a center plane PM of this movable unit, the winding 84 is associated with the winding 38 to form a phase, whereas the winding 86 of FIG Winding 39 is assigned to form another phase. The winding 40A has a length which substantially corresponds to twice the length of the further windings. In a variant, it is also possible to provide two windings which are similar to the other windings for the magnetic line 3OA associated phase. The centers of two non-contiguous windings 38 and 84 or 39 and 86, which form an identical phase, lie essentially equidistant from the center plane PM. This center plane runs parallel to the displacement direction X and perpendicular to the main plane of the magnetic track 24A. The center of gravity of the movable part 82 lies substantially in this center plane PM. The magnetic lines are arranged such that two magnetic lines 28 and 88 or 29 and 89, which are assigned to two windings forming an identical phase, are magnetically in phase, ie they have no offset between the magnets of the same polarity in the direction of displacement X. , Thus, the third embodiment of the invention is characterized in that each movable unit has, in addition to the first plurality of windings, a plurality of further windings associated with the plurality of phases of the linear motor, two windings associated with a same phase being arranged in a direction perpendicular to the direction of displacement, then in that their respective center points lie substantially equidistant from a median plane of the mobile unit under consideration, in which essentially their center of gravity is located. Two non-contiguous coils of a same phase are associated with two respective pluralities of magnets arranged so that these two coils are substantially in phase. In the particular case of a two-phase motor, only one of the phases of multiple windings can be formed.

FIG. 9 shows a fourth embodiment of an industrial device according to the invention, in which the magnets 74 and 94 are arranged obliquely to form the second embodiment described above. The magnetic track 24B of the linear motor 92 includes a first magnetic row 96 whose magnets 74 have a negative slope corresponding to a phase shift of 60 ° between the windings 38 and 39. The second magnetic row 98 is partially associated with the central winding 40A and the two windings 84 and 86. The magnets 94 of this second row are arranged obliquely with a positive slope, which also corresponds to a phase shift of 60 ° between the windings 84 and 86. The winding 4OA is superimposed on the two magnet rows 96 and 98. Overall, the electromagnetic phase shift of the winding 40A with respect to the windings of the other two phases is always +/- 120 °. Two windings associated with a same phase face two magnetized parts of the magnetic track 24B, which belong to the two magnet rows 96 and 98, respectively, which are magnetically in phase.

Claims

1. industrial device having at least one movable in a displacement direction (X) unit (32) and a magnetic track (24, 24A, 24B) with permanent magnets (6, 6A, 62, 74, 94), which are arranged in the direction of displacement of alternating polarity, these magnets defining a major plane (XZ) of the magnetic track, each movable unit including a plurality of windings (38, 39, 40, 40A) arranged to respectively define a different phase of a multi-phase linear motor is formed of this movable unit and the magnetic track, characterized in that the plurality of windings with their respective center are all substantially in a same plane (46) perpendicular to the displacement direction and in that the permanent magnets of the magnetic track are arranged so that each winding of the plurality of Windings with respect to the other windings of this plurality of windings is magnetically offset to different phases of Mehrphasenlinearm otors to define.

2. Industrial device according to claim 1, characterized in that the plurality of windings in a direction (Z) is arranged successively, which is perpendicular to the displacement direction (X) and parallel to the main plane (X-Z) of the magnetic track.

3. Industrial device according to claim 2, characterized in that the magnetic track has at least two pluralities (28, 29, 30) of permanent magnets with alternating polarity, which are associated with two respective different phases of each movable unit, wherein these two pluralities of magnets two respective Magnet rows form parallel and two opposite windings of the plurality of windings, which belong to these two respective phases, wherein the magnets of the first plurality of magnets with respect to the second plurality of magnets are magnetically offset in the displacement direction.

4. Industrial device according to claim 2, characterized in that the permanent magnets (62, 74) are arranged obliquely to the plane which is perpendicular to the displacement direction, so that the plurality of windings are magnetically offset from each other to define the different phases of the linear motor.

5. Industrial device according to claim 2, characterized in that each movable unit includes at least one further winding (84, 86) which is associated with at least one phase of the linear motor, wherein two of a same phase associated windings in the vertical direction (Z) are arranged such that their respective centers lie substantially equidistant from a center plane (PM) of the respective mobile unit which is parallel to the direction of displacement and in which is substantially its center of gravity, two non-contiguous coils of a same phase comprising two respective pluralities of magnets are arranged, which are arranged so that these two windings are substantially in phase.

6. Industrial device according to one of the preceding claims, characterized in that it contains a plurality of movable in the direction of displacement units (32, 34, 36) which are associated with the magnetic track.

7. Industrial device according to one of the preceding claims, characterized in that the at least one movable unit further comprises a motor module which is provided to allow a displacement of a part (76) of this unit in a direction perpendicular to the displacement direction.