EP4066365A1

EP4066365A1 - Transport device

Info

Publication number: EP4066365A1
Application number: EP20815759.4A
Authority: EP
Inventors: Stefan Flixeder; Michael HAUER; Martin HAUDUM
Original assignee: B&R Industrial Automation GmbH
Current assignee: B&R Industrial Automation GmbH
Priority date: 2019-11-27
Filing date: 2020-11-25
Publication date: 2022-10-05
Also published as: JP2023508259A; US20230026030A1; JP2023504039A; US20230006529A1; CN114731105A; WO2021105165A1; EP4066364A1; WO2021105166A1; CN114747125A

Abstract

The aim of the invention is to provide a transport device (1) in the form of a planar motor which facilitates a more efficient operation. According to the invention, this is achieved in that the transport unit can be moved in both main movement directions (H1, H2) with a different degree of efficiency and/or a different maximum force and/or a different degree of precision in that the drive coils (AS1, AS2) of the first and second coil groups (SG1, SG2) have different coil properties which influence the magnetic field and/or the transport unit drive magnets (4) which interact with the drive coils (AS1) of the first coil group (SG1) have different magnet properties which influence the magnetic field than the drive magnets (4) which interact with the drive coils (AS2) of the second coil group (SG2), wherein the at least one transport segment (2) is arranged in a position which deviates from a horizontal position such that a force component of a loading force acting on the transport unit during the operation of the transport device (1) is greater in the first main movement direction (H1) than a force component of the loading force in the second main movement direction (H2), said loading force including at least the weight force of the transport unit.

Description

Transport device

The invention relates to a transport device in the form of a planar motor with at least one transport segment that forms a transport plane and with at least one transport unit that can be moved at least two-dimensionally in two main directions of movement in the transport plane The first main direction of movement is defined and a second coil group with several drive coils is arranged, which defines the second main direction of movement and several drive magnets are arranged on the transport unit, the drive coils of the first coil group being controllable by a control unit in order to move at least some of the drive magnets of the transport unit of the transport unit to interact electromagnetically in the first main direction of movement and the drive coils of the second coil group can be controlled by the control unit in order to at least to cooperate electromagnetically with part of the drive magnets of the transport unit for moving the transport unit in the second main direction of movement, the transport unit being movable in the two main directions of movement with a different efficiency and / or a different maximum force and / or a different accuracy by the drive coils of the first and second coil group have different magnetic field influencing coil properties and / or the drive magnets of the transport unit interacting with the drive coils of the first coil group have different magnetic field influencing magnetic properties than the drive magnets cooperating with the drive coils of the second coil group. The invention also relates to a method for operating such a transport device.

Planar motors are basically known in the prior art. For example, US Pat. No. 9,202,719 B2 discloses the basic structure and mode of operation of such a planar motor. A planar motor essentially has a stator which forms a transport plane in which one or more transport units can be moved at least two-dimensionally. The stator is usually made up of one or more transport segments. In order to move the transport units in the transport plane, a driving force acting on the transport unit is generated in that a magnetic field of the stator (of the transport segment (s)) and a magnetic field of the transport unit interact. In order to cause the transport unit to move in a specific direction of movement, at least one of the magnetic fields, that is, that of the stator and / or that of the transport unit, must be variable over time in order to follow the movement of the transport unit. Usually, however, there is only one magnetic field in As a rule, the one at the stator changes over time and the respective other magnetic field (the one on the transport unit) is usually constant, i.e. does not change over time.

Temporally variable magnetic fields can be generated, for example, by coils (electromagnets), which can be arranged both on the transport unit and on the stator, in particular on the transport segment. The coils are often referred to as drive coils. Time-immutable, i.e. constant, magnetic fields are typically generated with the help of permanent magnets. These components are often referred to as drive magnets. Depending on the embodiment of the planar motor, these can also be arranged both on the transport unit and on the transport segment. Due to the simpler control, the drive coils are often arranged on the transport segment of the planar motor and the drive magnets on the transport unit.

The drive coils are usually controlled by a control unit in order to generate a moving magnetic field in the desired direction of movement. The drive magnets, which interact with the moving magnetic field, are arranged at least two-dimensionally distributed on the transport unit, so that a drive and levitation force can be generated on the transport unit. Due to the floating force, the transport unit can be kept in a constant position, e.g. an air gap between the transport unit and the transport segments can be generated or set and maintained .- Moments are generated. In order to enable the two-dimensional movement of the transport unit, which is characteristic of the planar motor, a two-dimensional interaction of the magnetic fields of the transport segments and the transport units is required, with one of the two magnetic fields in at least two dimensions or both magnetic fields in at least one dimension (which is complementary to the other dimension) in terms of time must be changeable. The drive coils and the drive magnets are advantageously arranged in such a way that, in addition to a one-dimensional movement along the axes spanned by the transport plane, more complex two-dimensional movements of the transport unit in the transport plane are also possible.

A planar motor can be used, for example, as a transport device in a production process, with very flexible transport processes with complex movement profiles being able to be implemented. In EP 3 172 156 B1 and EP 3 172 134 B1, for example, such applications of a planar motor as a transport device are shown. The stators of such planar motors can have different arrangements of drive coils and the arrangement of the drive magnets on the transport units can also be very different. In US Pat. No. 9,202,719 B2, for example, a planar motor with a multilayer structure of the stator with several superposed coil planes is disclosed. The drive coils in adjacent coil planes are orthogonal to one another in order to form two main directions of movement in which the transport units can be moved. On average, the coil planes thus have different distances from the drive magnets of the transport unit. This results in different degrees of efficiency of the planar motor in the two main directions of movement. To compensate for this, it is proposed to generate the drive force to apply a higher coil current to the drive coils of a coil level further away from the drive magnets of the transport unit than to the drive coils of a closer coil level.

In the publication J.M.M., Rovers, et. al, 2013. Design and measurements of the Double Layer Planar Motor. In: International Electric Machines & Drives Conference. Chicago, May 12-15, 2013. IEEE discloses a planar motor with a layered arrangement of two coil planes. In order to compensate for the different degrees of efficiency that result from the different distances from the magnets of the transport unit, it is proposed that drive coils of different heights be used for the two coil levels.

It is therefore an object of the invention to specify a transport device in the form of a planar motor and a method for operating a transport device in the form of a planar motor, which enable the transport device to be operated more efficiently.

According to the invention, the object is achieved in that the at least one transport segment is arranged in a position deviating from a horizontal position in such a way that a force component of a load force acting on the transport unit during operation of the transport device is greater in the first main direction of movement than a force component of the load force in the second main direction of movement, wherein the loading force includes at least one transport unit gravity of the transport unit.

Advantageous refinements of the transport device are given in the dependent claims 2-9.

The object is also achieved by a method according to claim 10. Advantageous refinements of the method are specified in the dependent claims 11 to 14. The present invention is explained in more detail below with reference to FIGS. 1 a to 6, which show exemplary, schematic and non-limiting advantageous embodiments of the invention. It shows

1a shows a transport device in the form of a planar motor in plan view,

1b + 1c each a transport device in the form of a planar motor in a side view,

2a-2e different possibilities for the arrangement of drive coils on a transport segment,

3a-3f different possibilities of a 1 D arrangement of drive magnets on a transport unit,

4a-4d different possibilities of a 2D arrangement of drive magnets on a transport unit,

5a-5e each shows the balance of forces on a transport unit on differently oriented transport segments and

6 shows a transport device in the form of a planar motor in an alternative embodiment in plan view.

In FIGS. 1a-1c, an exemplary embodiment of a transport device 1 in the form of a planar motor is shown in a simplified manner. FIG. 1a shows the transport device 1 in a top view and FIG. 1b + 1c shows the transport device 1 in a side view. The transport device 1 has at least one transport segment 2 as a stator, which forms a transport plane 3, and at least one transport unit TE, which can be moved at least two-dimensionally in two main directions of movement H1, H2 in the transport plane 3. In the context of the invention, the transport plane 3 is to be understood as the flat surface of the transport segment 2, which is determined by the size and shape of the transport segment 2. The transport level 3 is arranged horizontally here by way of example. For the sake of simplicity, FIG. 1a shows only one transport segment 2, but of course a large number of transport segments 2 (including different ones) could also be lined up in order to form a larger transport plane 3. As a result, the transport device 1 can have a modular structure and transport levels 3 of different sizes and areas can be implemented. Of course, this modular structure is only optional and only a single transport segment 2 could be provided in the form of a single assembly. In the transport level 3 of the transport segment 2, several, even different, transport units TE can of course also be moved simultaneously and independently of one another.

A first coil group SG1 with several drive coils AS1, which defines the first main direction of movement H1, and a second coil group SG2 with several drive coils AS2, which defines the second main direction of movement H2, are arranged on the transport segment 2. The drive coils AS1 of the first coil group SG1 are arranged one behind the other in a certain direction, here in the X direction, in order to form the first main direction of movement H1 for the movement of the transport unit TE, which here extends along the X axis. The drive coils AS2 of the second coil group SG2 are arranged one behind the other in a certain direction, here the Y direction, in order to form a second main direction of movement H2 for the transport unit TE, which here extends along the Y axis. The drive coils AS1, AS2 of the first and second coil groups SG1, SG2, as shown in Fig.la, are preferably arranged relative to one another in such a way that the two main directions of movement H1, H2 are normal to one another. Of course, a different relative arrangement of the main directions of movement H1, H2 would also be conceivable, for example an angle between the main directions of movement H1, H2 that deviates from a right angle.

The drive coils AS1 of the first coil group SG1 and the drive coils AS2 of the second coil group SG2 are each designed here as elongated, conventionally wound coils. The drive coils AS1 of the first coil group SG1 each have a longitudinal extension LAS1 in the Y direction and relatively smaller transverse extension QAS1 in the X direction and are arranged one behind the other in the direction of their transverse extension QAS1, here in the X direction. The transverse extension QASi of a drive coil ASi typically depends on the pole pitch Ti of the drive magnets 4 of the interacting magnet group MGi and / or the winding scheme of the drive coils ASi, i.e. whether it is, for example, a concentrated winding (single-tooth winding) or a distributed winding. The winding schemes are known in the art. The direction in which the drive coils AS1 of the first coil group SG1 are arranged one behind the other thus defines the first main direction of movement H1 for the movement of the transport unit TE. The drive coils AS1 of the first coil group SG1 are designed as so-called “long coils”. This means that its longitudinal extension LAS1 is greater than the extension of the transport unit TE in the respective direction (here the Y direction), here, for example, longer than a transport unit width BTE of the transport unit TE. In the example shown, the longitudinal extent LAS1 is essentially the same size as the extent of the transport segment 2 in the Y direction. In order to a movement of a transport unit TE in the X direction, that is to say in the first main direction of movement H1, is possible at essentially every point in the Y direction.

The drive coils AS2 of the second coil group SG2 also have a longitudinal extent LAS2, which here is less than the longitudinal extent LAS1 of the drive coils AS1 of the first coil group SG1. The longitudinal extension LAS2 of the drive coils AS2 of the second coil group SG2 runs here in the X direction. The drive coils AS2 of the second coil group SG2 also each have a smaller transverse extent QAS2 relative to their longitudinal extent LAS2, here in the Y direction. The transverse extent QAS2 is here essentially the same size as the transverse extent QAS1 of the drive coils AS1 of the first coil group SG1, but could also be larger or smaller. The drive coils AS2 of the second coil group SG2 are also arranged one behind the other in the direction of their transverse extent QAS2, here in the Y direction. The direction in which the drive coils AS2 of the second coil group SG2 are arranged one behind the other thus defines the second main direction of movement H2 for the movement of the transport unit TE.

The drive coils AS2 of the second coil group SG2 are designed as so-called “short coils”. This means that its longitudinal extension LAS2 is equal to or smaller than the extension of the transport unit TE in the respective direction (here the X direction), here e.g. the transport unit length LTE of the transport unit TE. However, in order to still enable a transport unit TE to move in the second main movement H2 in the entire transport level 3, the drive coils AS2 of the second coil group SG2 are arranged in several rows next to one another in the X direction, here e.g. in three rows. However, a reverse arrangement would just as well be possible, that is to say “long” coils for the second main direction of movement H2 and “short” coils for the first main direction of movement H1. It would also be possible to use “long” or “short” coils for both main directions of movement H1, H2. For example, it can be advantageous in terms of cost savings if identical drive coils AS1 = AS2 are used for both coil groups SG1, SG2.

Of course, the embodiment shown is only to be understood as an example, and the person skilled in the art could also provide a different arrangement of the coil groups SG1, SG2 and / or other designs of drive coils. For example, so-called PCB coils could be used in a known manner. PCB stands for "printed circuit board" and means that the coils are integrated directly into a circuit board. The two embodiments are known in the prior art, which is why no more detailed description is given at this point. Another relative arrangement of the coil groups SG1, SG2 to one another and / or to Transport segment 2 would be conceivable and / or further coil groups SGi with drive coils ASi could also be provided, which form further main directions of movement Hi. In the most common case, however, there are two differently oriented coil groups SG1,

SG2, each with a plurality of drive coils AS1, AS2, is sufficient, with each coil group SG1, SG2 defining a main direction of movement H1, H2. Preferably, however, the at least two main directions of movement H1, H2 are normal to one another as shown, so that the transport segment 2 can be constructed in a more simple manner.

For a modular structure of a transport level 3, which consists of several transport segments 2, it is also advantageous if the transport segments 2 each have a square or rectangular transport level 3. The transport segments 2 can then be lined up in a simple manner so that the respective first main direction of movement H1 of a transport segment 2 runs parallel or normal to the first main direction of movement H1 of the respectively adjacent transport segment 2. A transport level 3 can thus be constructed simply and flexibly from several transport segments 2. It is also not absolutely necessary here for adjacent transport segments 2 to be aligned with one another, rather an offset would also be possible.

With the illustrated transport device 1, for example, a substantially unrestricted movement of a transport unit TE in the two main directions of movement H1, H2 would be possible in the transport plane 3 of the transport segment 2. The transport unit TE could, for example, be moved only along the X-axis or only along the Y-axis. The transport unit TE can of course be moved in both main directions of movement H1, H2 at the same time, for example with a two-dimensional movement path BP located in the transport plane 3 with an X coordinate and a Y coordinate, as indicated on the transport unit TE in FIG . With a corresponding structural design of the transport segment 2 and the respective transport unit TE, the other four degrees of freedom of movement can also be used at least to a limited extent (translational movement in vertical direction Z and rotation about the three axes X, Y, Z).

A control unit 5 is also provided in the transport device 1, with which the drive coils AS1, AS2 of the transport segment 2 can be controlled, as indicated in FIG. 1a. The control unit 5 can, for example, also be connected to a higher-level system control unit 6 or be integrated into it. If several transport segments 2 are provided in the transport device 1, one (not segment control unit shown) and / or a coil control unit per drive coil ASi, which can also be integrated in the control unit 5. The movement path BP of a transport unit TE can be specified via the control unit 5 and / or the system control unit 6, for example as a function of a specific production process of a system in which the transport device 1 can be integrated.

As mentioned, several transport units TE can of course also be moved simultaneously and independently of one another on the transport device 1. The control unit 5 and / or the system control unit 6 then ensures that the movement sequences of the transport units TE are synchronized or coordinated with one another, for example in order to avoid a collision of transport units TE with one another and / or with transported objects. A control program runs on the control unit 5 which implements the desired movement paths of the individual transport units TE. The control unit 5 or the system control unit 6 can, for example, also be connected to a planning module PLM for planning the movement path BP. The planning module PLM can be, for example, a computer on which the actually set up transport device 1, in particular the transport level 3, is implemented virtually, for example.

A plurality of drive magnets 4 are arranged on the at least one transport unit TE and interact electromagnetically with the drive coils AS1, AS2 of the at least two coil groups SG1, SG2 to move the transport unit TE. For this purpose, the transport unit TE generally has a base body 9, on the underside of which (facing the transport plane 3) the drive magnets 4 are arranged, as can be seen in FIG. 1 b. In FIG. 1a, the main body 9 is shown broken away in large parts in order to be able to recognize the arrangement of the drive magnets 4.

In the example shown, two first magnet groups MGa and two second magnet groups MGb are arranged on the transport unit TE. A single first magnet group MGa and a single second magnet group MGb per transport unit TE are essentially sufficient to operate the transport device 1. Of course, more than two first magnet groups MGa and more than two second magnet groups MGb can also be arranged per transport unit TE. An unequal number of first and second magnet groups MGa, MGb would also be conceivable, for example two first magnet groups MGa and a second magnet group MGb. In each of the magnet groups MGa, MGb, a plurality of drive magnets 4 of different magnetization directions, arranged one behind the other in a specific arrangement direction with a specific pole pitch Ta, Tb, are provided. The The direction of arrangement of the first magnet groups MGa here corresponds to the X direction and the direction of arrangement of the second magnet groups MGb corresponds to the Y direction. The directions of arrangement are thus normal to one another, analogous to the main directions of movement H1, H2. The directions of arrangement of the magnet groups MGa, MGb preferably run as parallel as possible to the main directions of movement H1, H2 in order to enable the most efficient possible electromagnetic force generation. In the example shown, there is a known 1-D arrangement of the drive magnets 4 on the transport unit TE, but a likewise known 2D arrangement would also be possible, as will be explained in detail with reference to FIGS. 4a-4d.

In order to move the transport units TE in the transport level 3, the first and second drive coils AS1, AS2 can be controlled (energized) individually by the control unit 5. Any power electronics that may be required for this can be arranged in the control unit 5 or on the transport segment 2. A substantially moving magnetic field is generated in the first main direction of movement H1 by a corresponding time-shifted activation of the first drive coils AS1. The moving magnetic field in the first main direction of movement H1 mainly interacts electromagnetically with the drive magnets 4 of the first magnet group (s) MGa in order to generate the drive force for setting a predetermined movement state of the respective transport unit TE in the first main direction of movement H1, e.g. an acceleration, a constant one Speed or a deceleration to a standstill. Analogously, by controlling the second drive coils AS2 at different times, a substantially moving magnetic field is generated in the second main direction of movement H2, which predominantly interacts electromagnetically with the drive magnets 4 of the second magnet group (s) MGb to generate the drive force for moving the transport unit TE in the second main direction of movement To generate H2. Depending on the activation of the drive coils AS1, AS2, the moving magnetic fields are superimposed, as a result of which the transport unit TE can be moved in the desired manner along a predetermined two-dimensional movement path BP in the transport plane 3.

In addition to the two essentially unlimited translational degrees of freedom in the main directions of movement H1, H2 in the transport plane 3, a limited translational movement of a transport unit TE in the normal direction on the transport plane 3 is also possible, here in the direction of the Z-axis. In the illustrated arrangement of the transport segment 2, the Z-axis is perpendicular to the horizontal transport plane 3. Depending on the arrangement and structural design of the drive coils AS1, AS2 of the coil groups SG1, SG2 and of the first and second magnet groups MGa, MGb interacting therewith, a limited rotation of the transport units TE about the three spatial axes X, Y, Z is also possible.

As mentioned, adjoining drive magnets 4 of magnet groups MGa, MGb have a different magnetic orientation and are spaced apart by a certain pole pitch Ta, Tb (here from the center of a drive magnet 4 to the center of the adjacent drive magnet 4). In general, the magnetic field generated by the magnet group MGi changes its orientation by 180 ° within the pole pitch Ti. The necessary distance between the drive magnets 4 to generate a magnetic field with the desired pole pitch Ti also depends on the arrangement of the drive magnets 4 within a magnet group MGi, in particular on a gap width of a possibly provided gap between adjacent drive magnets 4, on the direction of magnetization of adjacent drive magnets 4 (e.g. 180 ° opposite or Halbach arrangement) and on the magnet width MBi of the drive magnets 4. In the Halbach arrangement, it can be advantageous, for example, if the outermost drive magnets 4 of a magnet group MGi have, for example, half the magnet width MBi of the drive magnets 4 in between .

This can mean, for example, that a magnetic north pole and a south pole alternate, as indicated in Figure 1a by the hatched and non-hatched drive magnets 4 on the transport unit TE, which corresponds to an arrangement of adjacent drive magnets 4 rotated by 180 °. The known Halbach arrangement has also proven to be advantageous, in which the direction of magnetization of adjoining drive magnets 4 is rotated by 90 ° with respect to one another. The pole pitch Ta, Tb is to be understood as the distance between two drive magnets 4, which are adjacent in the direction of arrangement, and have opposite magnetic orientation (north / south pole). If the drive magnets 4 have the same magnet width MB (in the direction of arrangement), adjacent drive magnets have an orientation direction rotated by 180 ° and the drive magnets 4 are directly adjacent to one another (which is usually the case), the pole pitch Ta, Tb corresponds to the respective magnet width MBa, MBb . The pole pitch Ta, Tb and the magnet width MBa, MBb are shown by way of example on the transport unit TE, FIGS. 4a and 4c.

During operation, an air gap L is provided between the transport plane 3 of the transport segment 2 and the drive magnets 4 of the magnet groups MGa, MGb of a transport unit TE, as can be seen in FIG. 1b. A, preferably magnetically conductive, cover layer is preferably also provided on the transport segment 2 in order to shield the drive coils AS1, AS2 lying underneath from external influences and essentially around one train smooth transport level 3. The cover layer is shown partially broken away in FIG. 1a in order to be able to recognize the arrangement of the drive coils AS1, AS2 located underneath. Similarly, a cover layer for covering the drive magnets 4 can of course also be provided on the transport units TE. The air gap L then extends between the cover layer and the drive magnets 4 of the respective transport unit TE. In order to generate and in particular to maintain the air gap L, the drive coils AS1, AS2 and the drive magnets 4 act in a known manner during operation not only to generate a drive force (which is required for movement in the main directions of movement H1, H2), but also to generate it a floating force FS together, here in the Z direction. The levitation force FS also acts when the transport unit TE is at a standstill, in order to generate and maintain the air gap L. In addition to the essentially horizontal installation position of the transport segment 2 shown in FIGS. 1 a + 1 b, an inclined installation position in the manner of an inclined plane would of course also be conceivable, as shown in FIG. 5b. An essentially vertical installation position according to FIG. 5c would also be possible. Of course, any other installation positions of the transport segment 2 are also possible.

The floating force FS is that part of the electromagnetically generated force that acts on the transport unit TE and the weight FG and a force component of a possible process force FP in the gravitational direction (e.g. weight of a transported object O and possibly also due to a work process in a process station of the Transport device 1 working process force acting on the transport unit TE) is directed in the opposite direction, as will be described in more detail below with reference to FIGS. 5a-e. Essentially, the levitation force FS corresponds in terms of amount to the vector sum of weight force FG and process force FP (in the gravitational direction), so that a static state of equilibrium of the transport unit TE is achieved while maintaining the air gap. The driving force is that part of the electromagnetically generated force that leads to a change in the state of motion of the transport unit TE (e.g. constant speed, acceleration, deceleration, etc.) or that part that is used in addition to the levitation force FS when the process force FP does not act in the direction of gravity must be in order to keep the transport unit TE at a standstill. In addition to the two-dimensional movement in the transport plane 3, a certain movement of the transport unit TE in the vertical direction is also possible, i.e. normal to the transport plane 3. By activating the drive coils AS1, AS2 accordingly, the air gap L can be increased and decreased to a limited extent, whereby the transport unit TE can be moved in the vertical direction, here in the Z direction, as indicated by the double arrow on the transport unit TE in FIG.

The size of the available freedom of movement in the vertical direction depends on the Essentially on the structural design of the transport device 1, in particular on the maximum magnetic field that can be generated by the drive coils AS1, AS2 and the drive magnets 4, as well as the mass and load on the transport unit TE. Depending on the size and design of the transport device 1, the available range of motion in the vertical direction can be, for example, in the range from a few mm to several centimeters.

Furthermore, it is provided that the drive coils AS1, AS2 of the first and second coil groups SG1, SG2 have different magnetic field-influencing coil properties and / or that the drive magnets 4 of the transport unit TE (here the first magnet group MGa) that predominantly interact with the drive coils AS1 of the first coil group SG1 Have magnetic field-influencing magnetic properties than the drive magnets 4 (here the second magnet group MGb) which predominantly interact with the drive coils AS2 of the second coil group SG2. As a result, the transport unit TE can be moved in the two main directions of movement H1, H2 with a different degree of efficiency mH1 F mH2 and / or a different maximum force and / or a different accuracy.

Coil properties influencing magnetic fields are to be understood as meaning changeable structural or energetic parameters of the drive coils ASi, by means of which the magnetic field generated by the drive coils ASi, in particular the magnetic flux, can be influenced. These include, for example, an average coil spacing Si of the drive coils ASi in the normal direction from the cooperating drive magnets 4 of the transport unit TE (FIG. 1 b), a coil pitch TASi of adjacent drive coils ASi of a coil group SGi, a conductor resistance of the drive coils ASi, a maximum that can be applied to drive coils ASi Coil current, a number of turns of the drive coils ASi and a coil geometry of the drive coils ASi. The coil geometry is to be understood in particular as the longitudinal extent LASi and the transverse extent QASi of the drive coils ASi parallel to the transport plane 3, as well as a reel height h _A si of the drive coils ASi normal to the transport plane 3, as indicated in Figure 1b on the drive coils AS2. The winding scheme also influences the coil geometry of the drive coils ASi, i.e. whether it is a concentrated winding or a distributed winding. Among the magnetic field-influencing magnetic properties of the drive magnets 4 of the transport unit TE are, for example, a remanent flux density of the drive magnets 4, a relative alignment between the drive magnets 4 and the drive coils ASi that interact with them, a pole pitch Ti of the drive magnets 4 and a magnet geometry of the drive magnets understand. The magnet geometry relates in particular to a magnet length LMi, the magnet width MBi and the magnet height HMi, as is shown by way of example in Fig.lb and Fig.3d.

In the following, some exemplary measures are listed as to how the efficiency pHi of the electromagnetic force generation of a main direction of movement Hi of the transport device 1 can be increased by means of the magnetic field influencing magnetic properties and / or the magnetic field influencing coil properties. Of course, several magnetic properties and / or coil properties can also be changed.

The relative alignment between the drive magnets 4 and the drive coils ASi should, if possible, take place in such a way that the conductor orientation of the drive coils ASi is orthogonal to the magnetic field generated by the drive magnets 4. In the practical embodiment, this is achieved, for example, by using elongated drive coils ASi and elongated drive magnets 4 of the magnet group MGi that interact therewith, which are arranged as parallel as possible to the longitudinal extension LASi (see e.g. FIG. 1a). In addition, the relative alignment between the drive coils ASi of a coil group SGi (e.g. SG1) and the magnet group MGi (e.g. MGb), which primarily interacts with the drive coils ASi of the other coil group SGi (e.g. SG2), should be as orthogonal as possible, so that little to no coupling effects arise. In the example according to FIG. 1a, this is achieved, for example, in that the drive magnets 4 of the second magnet groups MGb are arranged as parallel as possible to the transverse extension QAS1 of the drive coils ASi of the first coil group SG1. The distance between a conductor of a drive coil ASi and the drive magnets 4 interacting therewith (corresponds to the mean coil distance Si in the examples shown) should be as small as possible, since the flux density decreases exponentially with the normal distance.

The conductor resistance of the drive coil ASi should be as low as possible. Possibilities for reducing the conductor resistance are, for example, the provision of a so-called “covered length” of a drive coil ASi as high as possible and / or an increase in the cross section of the conductors of a drive coil ASi. The “covered length” is that part of the conductor which is in the area of influence of the magnetic field of the drive magnets 4. The “covered length” should preferably correspond to the entire extension of the conductor or the drive coil ASi. If several conductors are used to generate the drive force / levitation force, which is usually achieved by using drive coils ASi, a high copper fill factor is advantageous (the definition of the copper fill factor is basically known and essentially corresponds to the ratio between the sum of the cross-sectional area of the single conductor of a coil to the whole Cross-sectional area of the coil). Since the specific resistance of a conductor increases with temperature, the efficiency of a conductor can be increased by reducing the temperature, for example by dissipating heat.

The maximum force that can be generated on the transport unit TE (both in the direction of movement and in the vertical direction) can be influenced, for example, by the maximum coil current that can be applied to the drive coils ASi (which is essentially limited by the power electronics) and / or by the coil geometry and number of turns. The accuracy of the positioning of the transport unit TE can be influenced, for example, by the size of the coil pitch TASi. The coil pitch TASi denotes the distance between adjacent drive coils ASi, usually between the coil axes, as is indicated by way of example in FIG. It can be seen from this that there is a wealth of parameters with which the efficiency pHi of the movement of the transport unit TE, the maximum force that can be generated on the transport unit TE and / or the positional accuracy of the movement of the transport unit TE can be influenced. Of course, one could try to optimize all or as many as possible of the coil properties of the drive coils ASi that influence the magnetic field and the magnetic properties of the drive magnets 4 that influence the magnetic field. Often, however, this is not possible or not desired, e.g. for reasons of cost efficiency. For reasons of cost, for example, it may be advantageous to use coils of identical design for the drive coils AS1 of the first coil group SG1 and the drive coils AS1 of the first coil group SG2, whereby, for example, with different mean coil spacings S1 ^ S2 of the drive coils AS1, AS2, essentially automatically Difference in efficiency results. In the following, different mean coil distances S1 ^ S2 of the drive coils AS1, AS2 will be discussed with reference to FIGS. 1 a-1 c, the remaining magnetic field influencing coil properties and magnetic field influencing magnetic properties being uniform in both main directions of movement H1, H2.

The drive coils AS1 of the first coil group SG1 are in the normal direction (here in the Z direction) on the transport plane 3 at a mean first coil distance S1 from the first magnet group MGa and the drive coils AS2 of the second coil group SG2 are in the normal direction on the transport plane 3 in one , relative to the average first coil spacing S1, the greater average second coil spacing S2 is spaced from the second magnet group MGb, as can be seen in FIG. 1b. The drive coils AS1 of the first coil group SG1 are therefore closer to the drive magnets 4 of the first magnet group MGa in the Z direction than the drive coils AS2 of the second coil group SG2 are located on the drive magnets 4 of the second magnet group MGb. In the example shown in FIG. 1 b, the two coil groups SG1, SG2 are arranged one above the other.

The mean coil spacings S1, S2 are measured from the coil center of the respective drive coils AS1, AS2 in the Z direction. The drive coils AS1, AS2 are preferably ironless in order to avoid disruptive magnetic forces of attraction between the respective transport unit TE and the transport segment 2, so-called “air coils” are also used. In the example shown in Fig.1a + 1b, the drive coils AS1, AS2 are designed as conventionally wound, elongated coils with an essentially oval shape, each with a coil axis in the normal direction on the transport plane 3. The drive coils AS1, AS2 could also be so-called PCB Be executed coils. The drive coils AS1, AS2 of the respective coil group SG1, SG2 can, for example, also be arranged in layers in several first coil levels SE1 with first drive coils AS1 and several second coil levels SE2 with second drive coils AS2 in the normal direction to the transport level 3 one above the other on the transport segment 2, such as is shown in Fig.1c.

In the left example of FIG. 1c, a coil block with four first coil levels SE1 and a coil block with four second coil levels SE2 are arranged one above the other on the transport segment 2. In the illustration on the right in FIG. 1c, four first and four second coil planes SE1, SE2 are arranged alternately on the transport segment 2 in the Z direction. The average coil spacings S1, S2 are each the average spacing of the coil planes

J k ^ SU S2.i

SE1, SE2 from transport level 3 in the Z direction, where S \ = - - \ S2 = - - with the j k

Coil distances S1.i, S2.i of the first and second coil planes SE1, SE2 and number j, k of the first and second coil planes SE1, SE2.

The drive coils AS1 of the first coil group SG1 generate the same (maximum) with the same structural boundary conditions (identical geometry (length, width, height), same number of turns, etc.) and the same energetic boundary conditions (same maximum electrical current or voltage, etc.) Magnetic field like the drive coils AS2 of the second coil group SG2. The magnet groups MGa, MGb on the transport unit TE are essentially identical (same geometry (magnet length, magnet width, magnet height), same number of drive magnets 4, same pole pitch Ti, same magnetization directions, same magnetic field strength, etc.), so that magnet groups MGa , MGb generate magnetic fields of essentially the same size as those of the Drive coils AS1, AS2 generated magnetic fields interacting. Because the drive coils AS1 of the first coil group SG1 are on average closer to the drive magnets 4 of the first magnet group MGa than the drive coils AS2 of the second coil group SG2 to the drive magnets 4 of the second magnet group MGb, this leads to a higher efficiency of the electromagnetic force generation in the first main direction of movement H1 than in the second main direction of movement H2. This applies to both the generation of the driving force and the generation of the levitation force. This results in a higher efficiency in the first main direction of movement H1 in a known manner than in the second main direction of movement H2.

In FIGS. 2a-2e, various possibilities of arranging the drive coils AS1, AS2 of the first and second coil groups SG1, SG2 on a transport segment 2 are shown schematically. 2a + 2b show so-called “single-layer” or single-layer variants in which the first and second coil groups SG1, SG2 are arranged in the same plane. FIGS. 2c-2e show so-called “multi-layer” or multi-layer constructions in which the first and second coil groups SG1, SG2 are stacked in a vertical direction, as was explained above with reference to FIGS. 1b + 1c. In the case of a “double-layer” construction, for example, two layers of drive coils AS1, AS2 arranged one above the other are provided. The first main direction of movement H1 (with higher efficiency mH1> mH2) results essentially automatically (with otherwise the same magnetic field influencing coil properties and magnetic field influencing magnetic properties) because the drive coils AS1 of the first coil group SG1 are closer to the transport level 3 in the normal direction to the transport level 3 than the drive coils AS2 of the second coil group SG2.

The “single-layer” construction is usually used for transport devices 1 with two equivalent main directions of movement H1, H2. Here the drive coils AS1, AS2 of the first and second coil groups SG1, SG2 each have the same coil spacing S1 = S2 from the transport plane 3. With otherwise the same magnetic field influencing coil properties and magnetic field influencing magnetic properties, essentially the same efficiency mH1 = mH2 would result for the two main directions of movement H1, H2. As described, in addition to the coil spacing Si, there are also many other coil properties that influence magnetic fields and magnetic properties that influence magnetic fields, and by changing them, the efficiencies mH1, mH2 can be changed. It would therefore be fundamentally conceivable, even with a “single-layer” construction, to have different degrees of effectiveness mH1 ^ mH2 of the two main directions of movement H1, H2 generate, for example, by a different pole pitch Ta F Tb of the drive magnets 4 of the two magnet groups MGa, MGb and / or a different magnet geometry of the drive magnets 4 of the two magnet groups MGa, MGb.

In FIG. 2a, a so-called "herringbone" arrangement of the drive coils AS1, AS2 of the two coil groups SG1, SG2 is shown. In contrast to the other embodiments of FIGS. 2b-2e, the two main directions of movement H1, H2 here do not run parallel to the edges of the transport segment 2 (here in the X and Y directions), but rather at an angle thereto. Details on this can be found e.g. in Jansen, J. W., 2007. Magnetically levitated planar actuator with moving magnets. In: electromechanical analysis and Design Eindhoven: Technische Universiteit Eindhoven DOI: 10.6100 / IR630846 disclosed. FIG. 2c shows a “double-layer” embodiment in which “long” drive coils AS1, AS2 are provided both in the first coil group SG1 and in the second coil group SG2. FIG. 2d shows an embodiment with “long” drive coils AS1 in the first coil group SG1 and “short” drive coils AS2 in the second coil group SG2, analogous to FIG. 2e shows an example with “short” drive coils AS1 in the first coil group SG1 and “short” drive coils AS2 in the second coil group SG2.

In FIGS. 3a-f and 4a-d, different arrangements of drive magnets 4 on a transport unit TE are shown schematically. A basic distinction is made between a so-called 1 D arrangement (Fig. 3a-3f) and a 2D arrangement (Fig. 4a-4d). In the 1 D arrangement, as already described in detail, at least one first magnet group MGa with several drive magnets 4 for the first main direction of movement H1 (here X-axis) and at least one second magnet group MGb with several drive magnets 4 for the second main direction of movement H2 (here Y-axis) provided. The magnet groups MGa, MGb each have a certain number of drive magnets 4, in particular permanent magnets, arranged one behind the other in a certain arrangement direction (here MGa in the X direction and MGb in the Y direction). Adjacent drive magnets 4 have a different direction of magnetization. For example, the direction of magnetization of adjacent drive magnets 4 can be rotated by 180 ° to one another, that is, alternately magnetic north and south poles, as indicated by the hatched and non-hatched drive magnets 4. As mentioned, the drive magnets 4 of a magnet group MGi can also be arranged in the known Halbach arrangement, for example a drive magnet 4 with a magnetization direction rotated by 90 ° is provided between drive magnets 4 with opposite magnetization direction (north pole, south pole). The Halbach arrangement has the advantage that the magnetic flux on one side of the magnet group MGi (preferably the side facing the transport plane 3) is greater than on the opposite side. A particularly advantageous, sinusoidal magnetic field image of the magnetic field of a magnet group MGi can be achieved if the outermost drive magnets 4 of the magnet group MGi have a reduced, in particular half the magnet width MBi, than the drive magnets 4 of the magnet group MGi lying in between, as for example in FIG. 8 is shown. The Halbach arrangement is known in the prior art, which is why further details are dispensed with at this point.

In the 2D arrangement, individual drive magnets 4 with different magnetization directions are arranged essentially like a chessboard on the transport unit TE. The drive magnets 4 of different magnetization directions are arranged alternately and offset in two directions of arrangement (here the X and Y directions). The two directions are preferably oriented to one another in the same way as the two main directions of movement H1, H2, that is, for example, are normal to one another. It can be seen immediately that there are a number of different options for the arrangement, the most common variants of the 1 D arrangement being shown in FIGS. 3a-3f and the most common variants of the 2D arrangement in FIGS. 4a-4d. In the 2D arrangement, the first magnet group MGa corresponds to the drive magnets 4 arranged alternately in one direction (e.g. in the X direction) and the second magnet group MGb corresponds to the drive magnets 4 arranged alternately in the other direction (e.g. in the Y direction). The magnet groups MGa, MGb are not separated in the 2D arrangement, as in the 1 D arrangement, but the drive magnets 4 are both part of the first magnet groups MGa and part of the second magnet groups MGb.

For example, in a "single-layer" arrangement of the coil groups SG1, SG2 (Fig.2a + 2b) on a transport segment 2 (with otherwise identical magnetic field-influencing coil properties of the drive coils AS1, AS2) different efficiencies mH1, mH2 and / or different maximum force and / or to achieve different positioning accuracy of the transport unit TE, as already mentioned, the magnetic field-influencing magnetic properties of the drive magnets 4 of the transport unit TE can also be changed. One possibility is, for example, that the pole pitch Ta of the first magnet group (s) MGa differs from the pole pitch Tb of the second magnet group (s) MGb, as exemplified in FIGS the 2D arrangement is shown. If in the "double-layer" embodiment of the transport segment 2 shown in Fig.1a-1c, in which the drive coils AS1 of the first coil groups SG1 one have smaller coil spacing S1 than the drive coils AS2 of the second coil group SG2 also on the magnet groups MGa, MGb of the transport unit TE with different pole pitches Ta F Tb, the pole pitch Ta of the first magnet group MGa (which interacts with the first coil group SG1) is preferably smaller , as the pole pitch Tb of the second magnet group MGb. This is advantageous because the magnetic field generated by the drive magnets 4 penetrates further into the transport segment 2 with increasing pole pitch Ti in the Z direction. Therefore, the magnet group MGi with the larger pole pitch Ti interacts more efficiently with the drive coils ASi of the more distant coil group SGi.

As mentioned at the beginning, attempts have been made in the prior art to compensate for the difference in efficiency of the two main directions of movement H1, H2 in order to achieve main directions of movement that are as equivalent as possible with regard to the available electromagnetic force. In the present invention, on the other hand, the difference in efficiency between the two main directions of movement H1, H2 is used in a targeted manner, as will be explained in more detail below.

To maintain the air gap L, i.e. the floating state of the transport unit TE, it is necessary that the floating force FS counteracted by gravity (generated by the electromagnetic interaction of the drive coils AS1 with the drive magnets 4 of the first magnet group (s) MGa and drive coils AS2 with the drive magnets 4 of the second Magnet group / n MGb is generated) compensates for the weight FG of the transport unit TE plus any constant process forces FP (in the gravitational direction). Depending on the installation situation of the transport segment 2 of the transport device 1, the levitation force FS does not necessarily act in the normal direction on the transport plane 3 of the transport segment 2, as shown in FIGS. 5a-5e.

In the horizontal installation situation (Fig. 5a) the levitation force FS acts normal to the transport level 3 of the transport segment 2 (here vertically in the direction of the Z-axis), in the vertical installation situation (Fig. 5c-5e) the levitation force FS acts essentially parallel to the transport level 3 of the transport segment 2. When the transport segment 2 from FIG. 5a is inclined at an angle of inclination a = 90 ° only around the Y axis from the horizontal plane, the levitation force FS acts, for example, only in the direction of the X axis, as can be seen in FIG. 5c is, and thus at the same time in the first main direction of movement H1. In an installation situation (FIG. 5b) that lies between horizontal and vertical, corresponding components of the levitation force FS, FSx in the X direction and FSz in the Z direction result as a function of the angle of inclination a of the transport segment 2. The same applies, of course, to the YZ plane for a (not shown) inclination of the transport segment 2 from Figure 5a at an angle of inclination β only about the X-axis from the horizontal plane. For example, at an angle of inclination β = 90 °, the levitation force FS would act in an analogous manner only in the direction of the Y-axis and thus in the second main direction of movement H2.

In Figure 5d, the transport segment 2 is shown in plan view of the transport plane 3. The transport plane 3 of the transport segment 2 is inclined here at an angle of inclination a = 90 ° about the Y axis from the horizontal (analogous to FIG. 5c). In addition, the transport segment 2 is rotated at an angle of rotation g about the vertical axis normal to the transport plane 3, here the Z-axis, the rotation angle g being measured between the lower side of the rectangular, in particular square, transport plane 3 and the horizontal plane. The floating force FS is thus divided into a force component FSx in the X direction (which here also corresponds to the first main direction of movement H1) and a force component FSy in the Y direction (which here also corresponds to the second main direction of movement H2). The same naturally also applies to the case of an inclination (not shown) of the transport segment 2 at an angle of inclination β about the X axis and an additional rotation at an angle of rotation g about the Z axis.

In the example according to FIG. 5e, the transport segment 2 is aligned analogously to FIG. 5d. In addition, however, the transport unit TE is rotated at a relative angle f about the vertical axis (Z-axis) normal to the transport plane 3 with respect to the transport segment 2. This changes the magnetic properties influencing the magnetic field of the drive magnets 4 interacting with the drive coils AS1, AS2 of the two coil groups SG1, SG2. The assignment of the two main directions of movement H1, H2 (first main direction of movement H1 with higher efficiency mH1> mH2 in the X direction; second main direction of movement H2 with lower efficiency mH2 <mH1 in the Y direction) remain unchanged in the example shown, however, both efficiencies mH1, mH2 decrease compared to the arrangement according to FIG. 5d due to the suboptimal alignment between the drive magnets 4 and the drive coils AS1, AS2. Depending on the magnetic field influencing coil properties of the drive coils AS1, AS2 and the magnetic field influencing magnetic properties of the drive magnets 4, a rotation of the transport unit TE by a relative angle f could possibly also result in the main directions of movement H1, H2 reversing, e.g. H2 in the X direction and H1 in Y-direction with pHI> mH2).

In general, a position of the transport segment 2 that deviates from the horizontal position results in an angle of inclination a about the Y axis and / or a Inclination angle ß about the X-axis and / or an angle of rotation g about the Z-axis corresponding components of the levitation force FS, FSH1 in the first main direction of movement H1 (here FSx in the X direction), FSH2 in the second main direction of movement H2 (here FSy in y -Direction) and FSz in the Z-direction depending on the angles a, ß, g. The levitation force FS thus compensates for the weight FG caused by the mass of the transport unit TE and a force component of a possible process force FP in the gravitational direction, which is generated, for example, by a transported object O, as indicated in FIG (not shown) process station of the transport device 1 carried out work process acts on the transport unit TE. The position of the transport unit TE relative to the transport segment 2 can thus be kept constant during operation by the floating force FS. As mentioned at the beginning, a certain movement of the transport unit TE can also take place in the vertical direction (here in the Z direction), which can be achieved by appropriate control of the drive coils AS1, AS2.

The force component FSz of the levitation force FS normal to the transport plane 3, here in the Z direction (see, for example, FIG. 5b), can generally be applied both by the drive coils AS1 of the first coil group SG1 and by the drive coils AS2 of the second coil group SG2 . The force component FSH1 of the floating force FS in the first main direction of movement H1 (here FSx in the X direction) is generally only from the drive coils AS1 of the drive coils AS1 of the first coil group SG1 applied. The same naturally also applies to the case of an inclination (not shown) of the transport segment 2 at an inclination angle β about the X axis for the force component FSH2 of the levitation force FS in the second main direction of movement H2 (here FSy in the Y direction). The force component FSH2 would generally only be applied by the drive coils AS2 of the second coil group SG2. In the case of an inclination about both axes X, Y with the angles a, ß, the levitation force FS is divided according to the angle a, ß with the force components FSH1, FSH2 (or here FSx, FSy) on the drive coils AS1, AS2. The same naturally also applies to an inclination about the X-axis and / or the Y-axis and an additional rotation of the transport segment 2 by an angle of rotation g about the vertical axis, here the Z-axis.

In order to achieve the most efficient possible in an asymmetrically designed transport segment 2 with a first main direction of movement H1 with efficiency mH1 and a second main direction of movement H2 with relatively lower efficiency mH2 <mH1 (and / or with a higher maximum force in the first main direction of movement H1 relative to the second main direction of movement H2) To achieve operation is According to the invention, it is provided that a force component of a loading force acting on the transport unit TE during operation of the transport device 1 in the first main direction of movement H1 is greater than a force component of the loading force FB in the second main direction of movement H2. The loading force includes at least the transport unit gravity FG of the transport unit TE.

The loading force FB can, however, also contain the process force FP, the process force FP in turn being able to include an object weight force of an object O that can be transported with the transport unit TE and / or a work process force acting at least temporarily on the transport unit TE during a work process. For example, at least one process station (not shown) for carrying out a work process on the transport unit TE or on an object O that can be transported with the transport unit TE could be provided in the transport device 1, with a work process force at least temporarily appearing as part of the process force FP while the work process is being carried out the transport unit TE can act. The work process force can of course act on the transport unit TE in any direction in space, whereas the weight of the object acts in the gravitational direction. It can therefore be advantageous that the transport segment 2 is arranged relative to the process station in such a way that the loading force is predominantly in the first main direction of movement H1. In general, the loading force corresponds to a vector sum of the process force FP and the weight force FG of the transport unit TE, the process force FP including the work process force and / or the object weight force.

In the case of a non-horizontal position of the transport segment 2, an inclination of the transport segment 2 is preferably set in such a way that the force component of the loading force FB lying in the first main direction of movement H1 is at least 5% greater than the force component of the loading force FB lying in the second main direction of movement H2, preferably at least 10% larger, particularly preferably at least 20%. For example, the inclination of the transport segment 2 can be set so that the first main direction of movement H1 is at an angle of 90 ° ± 45 ° to the horizontal, as shown in FIG. 5c, for example, in which the transport segment 2 is at an angle a = 90 ° is inclined about the Y-axis from the horizontal.

The vector sum of the weight FG of the transport unit TE and the process force FP corresponding to the loading force acts perpendicularly and thus 100% in the first main direction of movement H1.

The control unit 5 of the transport device (see Fig.la) is preferably designed to interact with the drive magnets 4 of the transport unit TE To control drive coils AS1 of the first coil group SG1 in order to generate one of the force components of the loading force counteracting the force component in the first main direction of movement H1 and to control the drive coils AS2 of the second coil group SG2 which cooperate with the drive magnets 4 of the transport unit TE in order to control a to generate the force component of the loading force counteracting the force component in the second main direction of movement H2 in the second main direction of movement H2.

In the illustrated examples according to FIGS. 5a-5e, the loading force (consisting of the weight FG of the transport unit TE and the process force FP) acts, for example, only in the gravitational direction. The transport segment 2 is therefore preferably arranged in a position deviating from the horizontal position in such a way that the force component FSH1 of the electromagnetically generated levitation force FS in the first main direction of movement H1 (FIGS. 5b-5e force component FSx in the X direction) is greater than the force component FSH2 of the floating force FS in the second main direction of movement H2 (Fig. 5d + 5e force component FSy in the Y direction; in Fig. 5b + 5c there is no force component FSH2 in the second main direction of movement H2 or FSy in the Y direction, since the transport segment 2 only is inclined about the Y-axis). As a result, due to the advantageous orientation of the transport segment 2, the drive coils AS1 of the first main direction of movement H1 generate a greater proportion of the levitation force FS than the drive coils AS2 of the second main direction of movement H2, which means that a transport device 1 with an inclined (non-horizontal) Installation situation of the transport segment 2 a particularly efficient operation can be achieved.

In the examples shown, in which the process force FP, apart from the object weight force of the object O, does not contain any work process force acting externally on the transport unit TE, this means that the angle of inclination α about the Y-axis and / or the angle of inclination β about the X. -Axis and / or the angle of rotation g about the Z-axis are set so that the gravitational direction (here Z-direction) coincides as far as possible with the first main direction of movement H1 of the transport segment 2. The inclination (angle α, β, g) of the transport segment 2 is advantageously set such that the force component FSH1 of the levitation force FS in the first main direction of movement H1 is at least 5%, preferably at least 10%, particularly preferably at least 20% greater than that Force component FSH2 of the floating force FS in the second main direction of movement H1. The efficiency of the operation of the transport device 1 can thus increase at least to a certain degree, the greater the force component FSH1 floating force FS in the first Main direction of movement H1 is relative to the force component FSH2 of the levitation force FS in the second main direction of movement H2. If the levitation force FS lies completely in the first main direction of movement H1, this corresponds, for example, to the arrangement according to FIG. 5c, that is to say an inclination of the transport segment 2 at an inclination angle a = 90 ° only about the Y axis. In this case, however, the ohmic losses of the drive coils AS1, AS2 must also be taken into account, which occur during the operation of the transport device 1 and which are proportional to the square of the electrical coil currents. If, for example, all or almost all of the levitation force FS is applied by the drive coils AS1 in the first main direction of movement H1 (such as in the arrangement according to FIG. 5c), then the coil currents in the drive coils AS1 are relatively high compared to the coil currents in the drive coils AS2 of the second main direction of movement H2. This can mean that although the loading force FB acts essentially completely in the first main direction of movement H1, the efficiency of the transport device 1 cannot be increased, or only to a small extent, because the ohmic losses in the drive coils ASi increase disproportionately. For the most efficient possible operation of the transport device, it can therefore be advantageous to set the inclination of the transport segment 2 in favor of the first main direction of movement H1 within the meaning of the invention, but only to a certain extent. It can be seen from this that the establishment of an advantageous inclination of the transport segment 2 also depends on the specific design of the drive coils AS1, AS2. The determination of a certain inclination is therefore at the discretion of the person skilled in the art, depending on the application.

In FIG. 6, a further advantageous embodiment of the transport device 1 is shown in a plan view of the transport plane 3. The transport device essentially corresponds to the embodiment according to FIG. 1 a-1 c, which is why only the essential differences are discussed at this point. The stator of the transport device 1 here has several, in particular four, transport segments 2 of the same type, which together form the transport plane 3 in which at least one transport unit TE can be moved. In contrast to the embodiment according to Fig.la, the transport segments 2 are not rectangular, but each have the shape of a rhombus. In an analogous manner, the at least one transport unit TE is designed in such a way that a surface of the transport unit TE projected onto the transport plane 3 is designed in a diamond shape. Of course, the transport unit could also have a rectangular shape, as has been described, for example, with reference to FIGS. 3a-4d. The first main direction of movement H1 can, for example, be normal to a first edge K1 of the diamond-shaped transport plane 3 and the second main direction of movement H2 can be normal to the second edge K2 of the diamond-shaped plane adjoining the first edge K1 Transport level 3 are available. The transport segments 2 are each designed in such a way that the first edge K1 and the second edge K2 are arranged at a diamond angle w <90 ° to one another in order to form the diamond shape. Opposite sides in each case run parallel, as shown in Fig. 6.

As already described in detail, the directions of the two main directions of movement H1, H2 result from the arrangement of the drive coils AS1, AS2 of the coil groups SG1, SG2. Analogously to the example according to Fig.la, the drive coils AS1, AS2 of the first and second coil groups SG1, SG2 in the example shown are each designed as elongated coils with a longitudinal extension LAS1, LAS2 and a transverse extension QAS1, QAS2 that is normal thereon and is relatively smaller. In order to achieve different magnetic field-influencing coil properties, the drive coils AS1 of the first coil group SG1 can for example be closer to the transport plane 3 in the normal direction on the transport plane 3 (here in the Z direction) than the drive coils AS2 of the second coil group SG2. The first main direction of movement H1 thus runs orthogonally to the longitudinal extension LAS1 of the first drive coils AS1, here normal to the first edge K1 of the transport segments 2. The second main direction of movement H2 runs orthogonally to the longitudinal extension LAS2 of the second drive coils AS2, here normal to the second edge K2 of the transport segments 2 In the example shown, the second main direction of movement H2 consequently runs at a diamond angle w to the first main direction of movement H1. The diamond shape can advantageously be provided for the case when a desired angle between the main directions of movement H1, H2 is less than 90 °. In the case of a rectangular shape of the transport segment 2 (e.g. according to FIG. 1), this would be equally possible, but the drive coils AS1, AS2 would have to be arranged in at least one main direction of movement H1, H2 so that their longitudinal extension is no longer parallel to the edge of the rectangular transport plane 3 runs, which would be constructively more complex.

First magnet groups MGa and second magnet groups MGb, each with a plurality of drive magnets 4 of different magnetic orientations, are in turn arranged on the transport unit TE. The arrangement of the drive magnets 4 can take place as shown in FIG. 6 in the form of a 1-D arrangement with several elongate drive magnets 4 (see also FIGS. 3a-3f). Of course, a 2D arrangement with a checkerboard-like arrangement of drive magnets 4 would also be possible (see, for example, FIGS. 4a-4d). The 1 D and 2D arrangement has already been described in detail, which is why further details are not given here. The first magnet groups MGa are preferably arranged in the example according to Figure 6 so that the longitudinal direction of the drive magnets 4 of the first magnet group MGa runs as normal as possible to the first main direction of movement H1. Similarly, the second magnet groups MGb are preferably arranged such that the longitudinal direction of the drive magnets 4 of the second magnet groups MGb runs as normal as possible to the second main direction of movement H2. The movement of the transport unit TE, in particular due to a rotation of the transport unit TE around the vertical axis (here the Z-axis) can of course in turn result in deviations which, for example, can lead to a reduction in the efficiency mH1, mH2 of the two main directions of movement H1, H2, such as has already been described with reference to FIG. If the magnet groups MGa, MGb have the same magnetic field-influencing magnetic properties, this does not change the assignment of the two main directions of movement H1, H2, however.

The arrangement of the transport segments 2 according to the invention, which has already been described in detail, naturally also applies to the exemplary embodiment according to FIG. 6, which is why a detailed description is dispensed with at this point. The stator consisting of the four transport segments 2 is therefore preferably arranged in a position deviating from a horizontal position so that a force component of the loading force FB acting on the transport unit TE during operation of the transport device 1 is greater in the first main direction of movement H1 than a force component of the Loading force FB in the second main direction of movement H2. If the loading force FB contains, for example, only the weight FG of the transport unit TE and possibly the object weight of a transported object O, the transport segments 2 in FIG. 6 could for example be arranged in such a way that the first main direction of movement H1 is at an angle of 90 ° ± 45 ° is to the horizontal. If the loading force also includes a work process force, depending on the size and direction of the work process force, another advantageous arrangement of the transport segments 2 can of course also result.

Claims

1. Transport device (1) in the form of a planar motor with at least one transport segment (2) that forms a transport plane (3) and with at least one transport unit (TE) that is at least two-dimensional in the transport plane (3) in two main directions of movement (H1, H2 ) is movable, with a first coil group (SG1) with drive coils (AS1) being arranged on the transport segment (2), which defines the first main direction of movement (H1) and a second coil group (SG2) with drive coils (AS2) is arranged, which defines the second The main direction of movement (H2) is defined and drive magnets (4) are arranged on the transport unit (TE), the drive coils (AS1) of the first coil group (SG1) being controllable by a control unit (5) in order to use at least some of the drive magnets (4) of the transport unit (TE) to move the transport unit (TE) in the first main direction of movement (H1) to interact electromagnetically and the drive coils (AS2) of the second Sp ulengruppe (SG2) can be controlled by the control unit (5) in order to interact electromagnetically with at least some of the drive magnets (4) of the transport unit (TE) to move the transport unit (TE) in the second main direction of movement (H2), the transport unit (TE ) can be moved in the two main directions of movement (H1, H2) with a different degree of efficiency (mH1> mH2) and / or a different maximum force and / or a different accuracy, in that the drive coils (AS1, AS2) of the first and second coil groups (SG1, SG2) have different magnetic field-influencing coil properties and / or the drive magnets (4) of the transport unit (TE) that interact with the drive coils (AS1) of the first coil group (SG1) have different magnetic field-influencing magnetic properties than those with the drive coils (AS2) of the second coil group (SG2) ) cooperating drive magnets (4), characterized in that d The at least one transport segment (2) is arranged in a position deviating from a horizontal position in such a way that a force component of a loading force (FB) acting on the transport unit (TE) during operation of the transport device (1) is greater in the first main direction of movement (H1) , as a force component of the loading force (FB) in the second main direction of movement (H2), the loading force (FB) including at least one transport unit gravity (FG) of the transport unit (TE).

2. Transport device (1) according to claim 1, characterized in that an inclination of the transport segment (2) is set so that the force component of the loading force (FB) lying in the first main direction of movement (H1) is around is at least 5% greater than the force component of the loading force (FB) in the second main direction of movement (H2), preferably at least 10%, particularly preferably at least 20%.

3. Transport device (1) according to claim 1 or 2, characterized in that the loading force (FB) includes a process force (FP) acting at least temporarily on the transport unit (TE), the process force (FP) being an object gravity of one with the Transport unit (TE) transportable object (O) and / or a work process force acting at least temporarily during a work process on the transport unit (TE).

4. Transport device (1) according to claim 3, characterized in that at least one process station (PSi) is provided for carrying out a work process on the transport unit (TE) or on an object (O) which can be transported with the transport unit (TE), wherein during the Implementation of the work process at least temporarily the work process force acts as part of the process force (FP) on the transport unit (TE).

5. Transport device (1) according to one of claims 1 to 4, characterized in that the at least one transport segment (2) is diamond-shaped to form a diamond-shaped transport plane (3) and / or that a surface projected onto the transport plane (3) the at least one transport unit (TE) is diamond-shaped.

6. Transport device (1) according to claim 5, characterized in that the first main direction of movement (H1) is normal to a first edge (K1) of the diamond-shaped transport plane (3) and that the second main direction of movement (H2) is normal to a first edge (K1) adjacent, second edge (K2) of the diamond-shaped transport plane (3) is.

7. Transport device (1) according to one of claims 1 to 6, characterized in that the coil properties influencing the magnetic field are an average coil spacing (S1) of the drive coils (AS1, AS1) of the coil groups (SG1, SG2) in the normal direction of the drive magnets (4) Transport unit (TE) and / or a conductor resistance of the drive coils (AS1, AS2) of the coil groups (SG1, SG2) and / or a maximum coil current of the drive coils (AS1, AS2) of the coil groups (SG1, SG2) and / or a number of turns of the drive coils (AS1, AS2) of the coil groups (SG1,

SG2) and / or a coil geometry of the drive coils (AS1, AS2) are provided and / or that, as magnetic field-influencing magnetic properties of the drive magnets (4) of the transport unit (TE), a remanent flux density of the drive magnets (4) and / or a relative alignment between the drive magnets ( 4) and the drive coils (AS1, AS2) the coil groups (SG1, SG2) and / or a pole pitch (Ta, Tb) of the drive magnets (4) and / or a magnet geometry of the drive magnets (4) are provided.

8. Transport device (1) according to one of claims 1 to 7, characterized in that the control unit (5) is designed to drive the drive coils (AS1) of the first coil group (SG1) which cooperate with the drive magnets (4) of the transport unit (TE) to generate an electromagnetic force component (FSH1) in the first main direction of movement (H1) that counteracts the force component of the loading force (FB) in the first main direction of movement (H1) and the drive coils (4) of the transport unit (TE) interacting with the drive magnets (4). AS2) of the second coil group (SG2) to generate an electromagnetic force component (FSH2) counteracting the force component of the loading force (FB) in the second main direction of movement (H2) in the second main direction of movement (H2).

9. Transport device (1) according to one of claims 1 to 8, characterized in that the drive coils (AS1, AS2) of the first and second coil groups (SG1, SG2) each as elongated coils with a longitudinal extension (LAS1, LAS2) and a normal thereon and relatively smaller transverse extent (QAS1, QAS2) are formed, the first main direction of movement (H1) running orthogonally to the longitudinal extent (LAS1) of the first drive coils (AS1) and the second main direction of movement (H2) orthogonal to the longitudinal extent (LAS2) of the second Drive coils (AS2) runs.

10. A method for operating a transport device (1) in the form of a planar motor with at least one transport segment (2) that forms a transport plane (3) and with at least one transport unit (TE) that is at least two-dimensional in two main directions of movement in the transport plane (3) (H1, H2) is moved, with a first coil group (SG1) with several drive coils (AS1) being arranged on the transport segment (2), which defines the first main direction of movement (H1) and a second coil group (SG2) with several drive coils (AS2) which defines the second main direction of movement (H2) and drive magnets (4) are arranged on the transport unit (TE), the drive coils (AS1) of the first coil group (SG1) with at least some of the drive magnets (4) of the transport unit (TE) ) to interact electromagnetically to move the transport unit (TE) in the first main direction of movement (H1) and the drive coils (AS2) of the second coil group (SG2) to interact electromagnetically at least with part of the drive magnets (4) of the transport unit (TE) for moving the transport unit (TE) in the second main direction of movement (H2), the transport unit (TE) in the two main directions of movement (H1, H2) with different degrees of efficiency (mH1> mH2) and / or a different maximum force and / or a different accuracy by providing different magnetic field-influencing coil properties for the drive coils (AS1, AS2) of the first and second coil groups (SG1, SG2) and / or by providing for the drive coils with the drive coils (AS1) of the first coil group (SG1) cooperating drive magnets (4) of the transport unit (TE) different magnetic field influencing magnetic properties are provided than for the drive magnets (4) cooperating with the drive coils (AS2) of the second coil group (SG2), characterized in that the at least one transport segment (2) is arranged in a position deviating from a horizontal position in such a way that a force component of a load force (FB) acting on the transport unit (TE) in the first main direction of movement (H1) is greater than a force component of the load force ( FB) in the second main direction of movement (H2 ), wherein the loading force (FB) contains at least one transport unit gravity (FG) of the transport unit (TE).

11. The method according to claim 10, characterized in that an inclination of the transport segment (2) is set so that the force component of the loading force in the first main direction of movement (H1) is at least 5% greater than the force component of the loading force (FB) in the second main direction of movement (H2), preferably at least 10%, particularly preferably at least 20%.

12. The method according to claim 10 or 11, characterized in that the loading force (FB) includes a process force (FP) acting at least temporarily on the transport unit (TE), the process force (FP) being an object gravity with the transport unit (TE) ) transported object (O) and / or a work process force acting at least temporarily during a work process on the transport unit (TE).

13. The method according to claim 12, characterized in that the transport unit (TE) is moved into an area of a process station in which a work process is carried out on the transport unit (TE) or on an object (O) transported by the transport unit (TE) , the work process force acting on the transport unit (TE) at least temporarily while the work process is being carried out.

14. The method according to any one of claims 10 to 13, characterized in that the drive coils (AS1) of the first coil group (SG1) with the drive magnets (4) of the transport unit (TE) for generating one of the force components lying in the first main direction of movement (H1) the load force (FB) counteracting electromagnetic force component (FSH1) in the first main direction of movement (H1) and the drive coils (AS2) of the second coil group (SG2) with the Drive magnets (4) of the transport unit (TE) to generate an electromagnetic force component (FSH2) counteracting the force component of the loading force (FB) in the second main direction of movement (H2) in the second main direction of movement (H2).