Linear motor with capacitive power transfer

Abstract

The invention relates to a linear motor with capacitive power transfer. In order to provide a linear motor with improved capacitive power transfer from a stator to a shuttle of the motor, the linear motor (1) comprises a capacitive power transfer arrangement (10) with a power transfer capacitor (CPT) having a power transfer air gap (13) as a dielectric between a primary electrode (11) and a secondary electrode (12), wherein a motor air gap (6) and a power transmission air gap (13) of the linear motor (1) are parallel and are arranged adjacent to each other in a transverse direction (y).

Description

Technical Field

[0001] The present invention relates to a motor, and more particularly to a linear motor. Background Art

[0002] The present invention relates to a linear motor having a stator and at least one shuttle movable along the stator in a direction of motion, wherein a drive magnet is arranged along the stator in the direction of motion and a plurality of drive coils are arranged on at least one shuttle, or the drive magnet is arranged on the shuttle and a plurality of drive coils are arranged along the stator in the direction of motion, wherein the drive magnet and the plurality of drive coils face each other and are separated in a normal direction by a linear motor air gap, the linear motor air gap having a motor air gap distance in the normal direction, wherein the linear motor air gap extends in the direction of motion and in a transverse direction orthogonal to the direction of motion and the normal direction, wherein a capacitive power transmission arrangement is provided in the linear motor, the electric The capacitive power arrangement includes at least one primary electrode arranged on the stator and extending in the direction of motion, and further includes a secondary electrode arranged on the shuttle, the at least one secondary electrode facing the primary electrode and arranged in a normal direction opposite to the primary electrode, wherein the primary electrode and the secondary electrode are separated by a power transfer air gap, the power transfer air gap having a power transfer air gap distance in the normal direction, wherein the power transfer air gap extends in the direction of motion and in a lateral direction, and wherein the at least one primary electrode and the at least one secondary electrode form a power transfer capacitor, the power transfer capacitor having the power transfer air gap, the power transfer air gap serving as a dielectric for capacitive power transfer for transferring electrical energy from the stator to the shuttle.

[0003] Long stator linear motors (LLMs) are well-known transport devices. In an LLM, a drive coil is fixedly arranged along a stator that can extend along a long track. A drive magnet is arranged on the moving shuttle of the LLM. During operation of the LLM, the drive coil is energized by applying a drive coil voltage to the drive coil to generate an electromagnetic drive field. This electromagnetic drive field interacts with the magnetic field of the drive magnet on the shuttle to generate a propulsive force acting on the shuttle. This propulsive force causes the shuttle to move along the stator of the LLM. Examples of LLMs are given in WO 2013 / 143783 A1, US 6,876,107 B2, or US 2013 / 0074724 A1. In addition to the propulsive force, the interaction between the electromagnetic drive field and the magnetic field of the drive magnet can also generate a force transverse to the direction of motion. This transverse force can be used to guide the shuttle in a desired direction in an electromagnetic switch of the track. This is known, for example, from EP 3109998 B1.

[0004] One of the advantages of LLMs is that the shuttle does not need electrical energy to generate a magnetic field when permanent magnets are used as drive magnets. However, the main disadvantage is that the stator is rather complex because the drive coils need to be controlled individually. In addition to this, the drive coils generate rather much heat which is conducted into the stator which can require active cooling. This active cooling further increases the complexity of the stator. Last but not least, for efficient operation of the LLM, a small air gap between the drive coils and the drive magnets is required. But the smaller the air gap, the greater the risk that parts of the shuttle come into contact with parts of the stator. Thermal expansion of the stator can even exacerbate the problem. Mechanical contact between the stator and the shuttle is highly undesirable because it can cause severe damage to the stator and / or the shuttle and can even cause the LLM to shut down.

[0005] At least some of these problems do not occur in a different linear motor design called short stator linear motor (SLM). In the SLM, the drive coils are arranged on the shuttle and the drive magnets are arranged in the stator. Thus, the stator design is significantly simplified compared to the LLM. However, the SLM motor design requires electrical energy on the shuttle to drive the drive coils. Thus, in the SLM, electrical energy needs to be transmitted to the moving shuttle. This can be done using brush contacts. However, brush contacts are prone to failure and require regular maintenance. Therefore, contactless power transmission is preferred. The contactless power transmission can be inductive or capacitive.

[0006] However, there are also LLM applications where electrical energy needs to be transmitted to the shuttle. This can occur, for example, when the shuttle comprises actuators like clamps, hydraulic pumps or pneumatic pumps which need to be energized for their operation. Also in this LLM application, contactless power transmission is preferred and the contactless power transmission can be inductive or capacitive. The shuttle of the SLM can also comprise electrical components which need to be powered with electrical energy.

[0007] For example, inductive or capacitive power transmission is used for charging applications like charging mobile devices or electric cars. An example for capacitive charging is given in Regensburg, B. et al., “High-Performance Capacitive Wireless Power Transfer System for Electric Vehicle Charging with Enhanced Coupling Plate Design”, 2018 IEEE Energy Conversion Congress and Exposition (ECCE) Proceedings, pp. 2472-2477.

[0008] It is also known that inductive or conductive power transfer arrangements can be used simultaneously for data transfer to and from the shuttle. Such data transfer may be required in an SLM to send control commands to energize a drive coil on the shuttle, or in an LLM to send control commands to an actuator on the shuttle. The shuttle of the LLM or SLM can send measurement data or process parameters or data to a motor control unit. Therefore, bidirectional data transfer using inductive or conductive power transfer arrangements is very advantageous for transportation applications using linear motors. An example of this is given in "Capacitive Power Transfer System With Integrated Wide Bandwidth Communication" by Shaoge Zang et al., "IEEE Transactions on Power Electronics," Vol. 37, No. 8, pp. 8805-8810, published in August 2022.

[0009] WO 2020 / 188430 A1 illustrates inductive power transfer in an LLM transport system. However, this type of inductive power transfer can also be applied to SLMs. Contactless inductive power transfer utilizes the principles of magnetic induction to transfer power to the shuttle via inductively coupled transmitter and receiver coils. The main disadvantage of inductive power transfer is the need for transmitter and receiver coils along the track along which the power is transferred. These coils require space and generate significant heat during operation, presenting similar drawbacks as described above.

[0010] Capacitive power transmission is also known as a linear motor. EP 2 793 356 B1 and EP 2 903 407 A1 describe capacitive power transmission for SLMs. To this end, a first electrode is arranged on the shuttle and a second electrode is arranged on the stator, separated from the first electrode by an air gap. The two electrodes form a capacitor, with air between them serving as a dielectric for power transmission. In EP 2 793 356 B1, the drive coil is arranged behind the electrode for power transmission. This increases the air gap of the electromagnetic drive field and thus reduces the possible propulsion force. For higher propulsion forces, significantly higher coil voltages are required. In EP 2 903 407 A1, the drive coil is offset by 90° from the electrode for power transmission. This allows for an optimal air gap between the drive coil and the drive magnet and between the two electrodes for capacitive power transmission.

[0011] However, in both EP 2 793 356 B1 and EP 2 903 407 A1, the SLM has only very simple tracks in the form of short straight tracks. For drive shafts or working machines, such simple tracks are often sufficient, as in EP 2 793 356 B1 and EP 2 903 407 A1. However, in transport systems, the tracks along which the shuttle can move often have more complex shapes, with straight sections, bends (of varying curvatures), inclined sections, and often also switches connecting different tracks of the transport system. For such tracks, and especially for bends, capacitive power transmission designs such as those described in EP 2 903 407 A1 are unsuitable. Due to the 90° offset between the drive coil and the electrodes for power transmission, the air gap between the drive coil and the drive magnet, or the air gap between the electrodes for power transmission, changes at the bends of the motor track due to the curvature of the bends. Therefore, the capacitive power transmission or the drive of the shuttle will be affected in the motor track curve and will not operate effectively. Compensating for these effects will require higher power for the capacitive power transmission or drive, which will increase losses and heat. Summary of the Invention

[0012] The object of the present invention is to provide a linear motor (LLM or SLM) with improved capacitive power transmission from the stator to the motor shuttle. This object is achieved by a linear motor according to claim 1.

[0013] By arranging the primary and secondary electrodes so that the power transmission air gap between them is oriented parallel to the motor air gap, this ensures that the air gap is unaffected when the stator bends in one direction, and is equally affected when the stator bends in the other direction. This allows linear motors with complex geometries (particularly, with curved sections) without negatively impacting the efficiency of power transmission (and / or capacitive data communication).

[0014] The power transmission capacitor formed by the primary electrode and the secondary electrode coupled thereto can additionally be used for capacitive data communication. Alternatively, more than one capacitor can be provided, such that at least one capacitor is used for power transmission and another capacitor is used for data communication.

[0015] When more than one power transfer capacitor is provided, the electrical energy that can be transferred to the shuttle can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Reference below Figures 1 to 5 To describe the invention in more detail, the figures show schematic and non-limiting advantageous embodiments of the invention by way of example. In the drawings:

[0017] Figure 1 shows a closed short stator linear motor stator track with capacitive power transmission of the present invention,

[0018] Figure 2 is a cross section through the stator and the shuttle on the stator,

[0019] Figure 3 is a cross section of a stator track of a long stator linear motor with capacitive power transmission of the present invention, and

[0020] Figure 4 and Figure 5 It is a different concept of capacitive power transfer. DETAILED DESCRIPTION

[0021] In the following, linear motor refers to both motor concepts, namely long-stator linear motor (LLM) and short-stator linear motor (SLM).

[0022] Figure 1 A short stator linear motor (SLM) is shown as an example of a linear motor 1. The linear motor 1 has a stator 2 and at least one shuttle Tn movable along the stator 2. "n" serves as an index to be able to distinguish between different shuttles when needed, while Tn is used in the following where no specific shuttle is mentioned. The stator 2 is stationary and the shuttle Tn moves relative to the stator 2. The stator 2 of the linear motor 1 can have any shape and geometry. The stator 2 can include straight track sections and curved track sections, possibly also curved in different directions. In Figure 1 In the example shown, the stator 2 is designed as a closed loop extending two-dimensionally within a plane, with two 180° bends connected by a straight track section. However, the stator 2 need not extend within a plane and can also extend three-dimensionally, which requires bending in different directions. The stator 2 can also include multiple stator segments Sm. "m" serves as an index to distinguish different stator segments when necessary, and Sm is used below when no specific stator segment is mentioned. Each stator segment Sm can have a given shape and geometry, such as a bend with a specific curvature or bend length, a straight line, a switch, etc. The stator segments Sm are arranged adjacent to each other in the direction of movement x of the shuttle Tn along the stator 2 to form the desired stator 2 for a given application.

[0023] The track of the stator 2 defines a direction of movement x. When driven, the shuttle Tn can move along the stator 2 in the direction of movement x.

[0024] In order to drive the shuttle Tn of the SLM, a driving magnet 3 is arranged along the stator 2, which is usually a permanent magnet or an electromagnet (such as Figure 1 and Figure 2As shown in FIG. 1 , a plurality of drive coils 4 are arranged on the shuttle Tn. Typically, more than one drive coil 4 is provided. When energized with a drive coil voltage, the plurality of drive coils 4 generate an electromagnetic drive field. This electromagnetic drive field interacts with the magnetic field of the drive magnet 3 in the region of the shuttle Tn to generate a propulsion force F. P This propulsion force causes the shuttle Tn to move along the stator 2 in the desired direction of movement x.

[0025] In a well-known manner, by controlling the propulsion force F P The kinematics (position, velocity, acceleration, jerk) of the shuttle Tn along the stator 2 can be controlled. The motion of each shuttle Tn on the stator 2 can also be controlled independently. The propulsion force F is controlled by controlling the energization of the drive coil 4. P .

[0026] Figure 2 A cross-section of a shuttle Tn of an SLM on a stator 2 is shown. In this embodiment, a plurality of drive coils 4 of the shuttle Tn are arranged on a laminated core 5 made of a highly magnetically conductive material (e.g., an iron-based material). For example, each of the plurality of drive coils 4 is arranged on a tooth of the laminated core 5. The plurality of drive coils 4 and the drive magnets 3 on the stator 2 face each other. The plurality of drive coils 4 are arranged opposite the drive magnets 3 on the stator (in the direction z), with a motor air gap 6 therebetween. The motor air gap 6 is the air space between the drive coils 4 and the drive magnets 3.

[0027] The motor air gap 6 extends two-dimensionally in a transverse direction y and in a direction of motion x, with the transverse direction y being substantially defined by the surface of the stator 2 facing the shuttle Tn. The motion direction x and the transverse direction y span the plane of motion of the SLM, along which the shuttle Tn moves. In a direction z orthogonal to the motion direction x and the transverse direction y, the motor air gap 6 has an air gap distance L. This air gap distance L is crucial for the efficiency of the linear motor 1. For efficient operation of the SLM, the air gap distance L should be as small as possible, as this increases the electromagnetic field strength in the motor air gap 6.

[0028] exist Figure 2 , the shuttle Tn is also shown to include a shuttle body 7, on which the drive coil 4 and possibly the laminated core 5 are arranged. The shuttle body 7 is typically made of a non-magnetic material, or at least a material with very low magnetic permeability. It is further shown that the drive coil 4 can be covered by a drive coil cover 16 for protecting the drive coil 4. Furthermore, the drive magnet 3 on the stator 2 is typically covered by a magnet cover 17 for protecting the drive magnet 3.

[0029] exist Figure 3In FIG, a cross section of a track of a linear motor 1 in the form of an LLM is shown. In the case of an LLM, the drive coils 4 are arranged on the stator 2 adjacent to each other in the direction of movement x. The drive magnets 3 are arranged on the shuttle Tn and opposite the drive coils 4 (in the z direction). Figure 3 In the embodiment of FIG. 1 , the drive coil 4 is covered by a drive coil cover 16, and the drive magnet 3 is covered by a magnet cover 17. As in the case of the SLM, the drive coil 4 in the region of the shuttle Tn is driven by a drive coil voltage v c Power is supplied to generate an electromagnetic field that interacts with the magnetic field of the driving magnet 3 , thereby generating a propulsive force acting on the shuttle Tn, causing the shuttle Tn to move along the stator 2 .

[0030] Despite Figure 3 It is not clearly shown in the text, but in the case of LLM, as mentioned above about Figure 2 As described in the SLM, a motor air gap 6 is also provided between the drive coil 4 (facing the motor air gap 6) and the drive magnet 3 (facing the motor air gap 6). The motor air gap 6 has an air gap distance L in the direction z.

[0031] exist Figure 3 In the embodiment shown, there are two primary electrodes 11 arranged on the stator 2, and both primary electrodes 11 are located on one side of the stator 2 (as viewed in the transverse direction). Therefore, the associated secondary electrode 12 on the shuttle Tn is also located on one side of the drive magnet 3. However, it is also possible to provide at least one primary electrode 11 on each side of the stator 2 (as viewed in the transverse direction). In this case, at least one associated secondary electrode 12 on the shuttle Tn is also located on each side of the drive magnet 3.

[0032] Typically, the shuttle Tn also includes a guide member 8 for guiding the shuttle Tn along the stator 2. To this end, the stator 2 also includes a guide member 9, and the shuttle guide member 8 interacts with the stator guide member 9 for guiding the shuttle Tn. Figure 2 and Figure 3 In an embodiment of the linear motor 1 , the shuttle guide member 8 is a roller rotatably arranged on the shuttle Tn, in particular arranged on the shuttle body 7, and the stator guide member 9 is formed by a guide rail on which the roller rolls during operation of the SLM.

[0033] exist Figure 3 It is also indicated in the figure that the linear motor 1 is further provided with a motor control unit 20, which uses the drive coil voltage v c The energization of the drive coil 4 is controlled so as to move the shuttle Tn in a desired manner (eg, speed, acceleration). Although obvious and well known, it is worth mentioning that the drive coil voltage v of different drive coils 4 cNot necessarily the same, but usually different.The motor control unit 20 is typically microprocessor-based hardware on which control software runs.

[0034] In order to provide electrical energy to the shuttle Tn of the linear motor 1, such as the electrical energy required to energize the drive coil 4 and generate the electromagnetic drive field (SLM), or the electrical energy required to energize the electrical components on the shuttle Tn (LLM or SLM), the linear motor 1 is provided with a capacitive power transfer (CPT) arrangement 10 for transmitting electrical energy from the stator 2 to the shuttle Tn.

[0035] CPT arrangement 10 (eg Figure 2 and Figure 3 The linear motor (shown in FIG. 1 ) includes at least one primary electrode 11 arranged on at least one section of the stator 2. The primary electrode 11 extends along the stator 2 in the direction of motion x. The length of the primary electrode 11 in the direction of motion y is preferably longer than the length of the shuttle Tn in the direction of motion x, and is typically much longer than the length of the shuttle Tn in the direction of motion x. Preferably, the primary electrode 11 extends along the entire length of the stator 2 of the linear motor. The primary electrode 11 is arranged at least in the section of the stator 2 where power is to be transmitted to the shuttle Tn. At least one secondary electrode 12 is arranged on the shuttle Tn. The primary electrode 11 and the secondary electrode 12 are arranged opposite each other (in the direction z) and face each other, forming a power transmission air gap 13 between the primary electrode 11 and the secondary electrode 12. Like the motor air gap 6, the power transmission air gap 13 is an air gap between at least one primary electrode 11 and the opposing secondary electrode 12 and extends two-dimensionally in the direction of motion x and the transverse direction y. In the direction z, the power transmission air gap 13 has an air gap distance T (only in Figure 2 For efficient power transmission, the air gap distance T of the power transmission air gap 13 should be as small as possible in the normal direction z. Preferably, but not necessarily, the air gap distance L of the motor air gap 6 and the air gap distance T of the power transmission air gap 13 are equal.

[0036] According to the present invention, the motor air gap 6 and the power transmission air gap 13 are arranged adjacent to each other in a transverse direction y, which is orthogonal to the direction x of movement of the shuttle Tn along the stator 2 and to the normal direction z, in which the motor air gap distance L and the power transmission air gap distance T are given. The motor air gap 6 and the power transmission air gap 13 are separate and therefore do not overlap and are parallel to each other.

[0037] “Parallel” means that the motor air gap 6 and the power transmission air gap 13 are at least line-parallel in a cross section orthogonal to the direction of motion x, i.e. in the yz plane (e.g. Figure 2(as shown). On straight sections of the stator 2, the entire motor air gap 6 and the power transmission air gap 13, which also extend in the direction of motion x, will be parallel. On curved sections of the stator 2, the direction of motion x is, of course, a tangent to the curvature of the curve. In this case, due to the curve, the motor air gap 6 and the power transmission air gap 13 vary in the direction of motion x, and the motor air gap 5 and the power transmission air gap 13 are parallel in every cross section orthogonal to the direction of motion x.

[0038] The advantage of the arrangement of the primary electrodes 11 and the secondary electrodes 12 according to the invention close to the short stator motor air gap 6 in the transverse direction y is that bending the stator 2 about the normal direction z or about the direction of motion x does not affect the motor air gap 5 and the power transmission air gap 13. Figure 1 As shown in FIG2 , when the motor is bent around the direction of motion x, the motor air gap distance L and the power transmission air gap distance T will remain unchanged. Since the air gap 6 and the air gap 13 are not affected, the motor drive and power transmission are also not affected.

[0039] When the stator 2 is bent about the transverse direction y, both air gaps 6 and 13 are affected, since the distance between the shuttle Tn and the stator 2 changes due to the curvature of the bend and the length of the shuttle Tn in the direction of movement x. However, the air gaps 6 and 13 are also affected in the same way, which simplifies the compensation of the variations of the air gaps 6 and 13 to avoid the propulsion force F p generation or have a negative impact on power transmission.

[0040] In the event that the stator 2 is curved about the transverse direction y, the guides of the shuttle Tn (the shuttle guide member 8 and / or the stator guide member 9) can be adjusted in the area of ​​the curve so that the resulting average air gap distances L, T when the shuttle Tn travels along the curve are equal to the air gap distances L, T on the straight sections of the stator 2. This will compensate for the effect of the changing air gaps 6, 13 on the drive or power transmission of the shuttle Tn when the shuttle Tn travels through such a curve.

[0041] However, the curvature of the stator 2 about the transverse direction y can be advantageously used to implement a switch. For the switch, the shuttle Tn requires drive coils 4 (SLM) or drive magnets 3 (LLM) on both sides in the normal direction z, and stators 2 on both sides in the normal direction z of the shuttle Tn. The shuttle Tn will move between the two stators 2. The LLM is described in EP 3 109 998 B1 and can be easily adapted to also include a CPT arrangement 10 ( Figure 3 The embodiment shown shows secondary electrodes on both sides in the normal direction z). However, such a switch can also be implemented with an SLM, such as Figure 2As shown. To this end, the shuttle Tn is essentially mirrored about the transverse direction y, so that on both sides in the normal direction z it comprises a drive coil 4 and at least one secondary electrode 12. On both sides in the normal direction, the stator 2 is arranged. In the region of the switch, the stators 2 on both sides will be separated from each other in the normal direction z.

[0042] The primary electrode 11 and the associated secondary electrode 12 form a power transfer capacitor C PT , with a power transmission air gap 13 as a dielectric in between, which is used for capacitive power transmission to transmit electric energy for powering at least one of the multiple drive coils 4 (SLM) or for powering electrical components (SLM, LLM) on the shuttle Tn from the stator 2 to the shuttle Tn.

[0043] In a preferred embodiment of the linear motor 1 of the invention, two separate primary electrodes 11 are provided on the stator 2 and two separate secondary electrodes 12 are provided on the shuttle Tn. Each of the primary electrodes 11 is connected to one of the secondary electrodes 12, in each case forming a power transfer capacitor C PT , with a power transmission air gap 13 as a dielectric therebetween, as described above.

[0044] Typically, in capacitive power transmission, electrical energy is transferred through the power transfer capacitor C PT The electric field generated between the primary electrode 11 and the secondary electrode 12 is transmitted. To this end, the alternating current (AC) primary voltage v provided by the AC power supply 15 p is applied to the primary electrode 11, thereby generating an oscillating electric field, which induces an AC secondary voltage v on the secondary electrode 12 through electrostatic induction. s This in turn makes the AC secondary current i s The current flows in an electric load 18 connected to the secondary electrode 12. The electric load 18 may be the drive coil 4, an electrical component, or an electric energy storage device.

[0045] Figure 4 This well-known principle of capacitive power transfer is exemplarily shown. Figure 4 In the embodiment of the present invention, an optional AC / DC converter 14 is provided between the secondary electrode 12 and the load 18 for converting the AC secondary voltage v s and the AC secondary current i s Converted to DC secondary voltage v s and the DC secondary current i s .

[0046] Figure 5 shows the use of two power transfer capacitors C PTThe AC power source 15 applies an AC primary voltage v having a phase difference of 180° to the primary electrode 11. p . Power transmission capacitor C PT The generated electric field in the secondary electrode 12 induces an AC secondary voltage v s , which in turn causes the secondary AC current i s Flows back and forth between the secondary electrodes 12 and passes through the load 18 connected thereto. An AC / DC converter may be provided between the load 18 and the secondary electrodes 12, which provides a DC secondary voltage V to the load 18. s and DC secondary current I s .

[0047] The amount of power transferred using the capacitive power transfer arrangement 10 varies with the AC primary voltage v p The frequency and power transmission capacitor C PT The capacitance (which is inversely proportional to the distance between the primary electrode 11 and the secondary electrode 12 in the normal direction z) increases. This means that for a given AC primary voltage v p , the smaller the power transmission air gap distance T, the more power can be transmitted.

[0048] If resonant power transfer is used, capacitive power transfer can be improved. In this case, the power transfer capacitor C PT It can be integrated into an electric resonant circuit because the choke (inductor) is connected in series or in parallel to the secondary electrode 12. In addition, the primary electrode 11 can be connected in series or in parallel to the choke (inductor). The resonant circuit can also include additional passive electrical components such as capacitors, inductors or resistors. By tuning the choke (inductor value) to the power transfer capacitor C PT , the resonant circuit can be operated at or near resonance. By adjusting the AC primary voltage v p The choke (inductor) and optional additional electrical components can be arranged on the circuit board 22 provided on the shuttle Tn (only in Figure 2 shown in ).

[0049] The transmitted electrical energy can also be stored in the electrical energy storage device 21 on the shuttle Tn (only in Figure 2 ), like a battery in a supercapacitor.

[0050] In the SLM as a linear motor 1, the electrical energy transmitted by the CPT arrangement 10 is primarily used for the shuttle Tn for energizing the plurality of drive coils 4 that drive the shuttle Tn. However, the electrical energy may also be used to power any other electrical components on the shuttle Tn, such as actuators, grippers, pumps, or devices for data communication on the shuttle Tn.

[0051] The CPT arrangement 10 can also be used for data communication between the shuttle Tn and the motor control unit 20, also for bidirectional data communication. Figure 4 The primary electrodes 11 on the stator 2 are coupled to a first data communication unit 25. The first data communication unit 25 is connected to the motor control unit 20, for example, via a data communication bus 27. The first data communication unit 25 can transmit the AC communication signal v s Superimposed on the AC primary voltage v p Any possible modulation scheme, such as frequency modulation or amplitude modulation, can be used to modulate the AC communication signal v s For data communication. AC primary voltage v p and AC communication signal v s At the secondary side, the AC secondary voltage v is obtained by the second data communication unit 26 on the shuttle Tn (for example by demodulation or filtering). s Restore AC communication signal v s Or represents AC communication signal v s For bidirectional data communication, the communication will be in the other direction, ie from the second data communication unit 26 to the first data communication unit 25.

[0052] However, it is possible to provide only a single primary electrode 11 and an associated secondary electrode 12 for data communication. In this case, power transmission and data communication are separated. For example, in Figure 2 In the embodiment, one of the primary electrode 11 / secondary electrode 12 pair can be used for power transmission and the other for data communication. Alternatively, an additional primary electrode 11a on the stator 2 and an additional secondary electrode 12a on the shuttle Tn form an additional capacitor C for data communication. PTa This is Figure 5 The additional primary electrode 11a is connected to the first data communication unit 25, and the additional secondary electrode 12a is connected to the second data communication unit 26. However, the additional primary electrode 11a and the additional secondary electrode 12a for data communication are arranged as described above for power transmission, i.e. the additional air gap 13a between them is parallel to the motor air gap 6 and separated from (does not overlap) the motor air gap 5.

Claims

1. A linear motor comprising a stator (2) and at least one shuttle (Tn) movable along the stator (2) in a direction of motion (x), wherein a drive magnet (3) is arranged along the stator in the direction of motion (x) and a plurality of drive coils (4) are arranged on the at least one shuttle (Tn), or a drive magnet (3) is arranged on the shuttle (Tn) and a plurality of drive coils (4) are arranged along the stator (2) in the direction of motion (x), wherein the drive magnet (3) and the plurality of drive coils (4) face each other and are separated in a normal direction (z) by a motor air gap (6), the motor air gap having a motor air gap distance (L) in the normal direction (z), wherein the motor air gap (6) extends in the direction of motion (x) and in a transverse direction (y) orthogonal to the direction of motion (x) and the normal direction (z), wherein a capacitive power transmission arrangement (10) is Provided in the linear motor (1), the capacitive power transfer arrangement (10) comprises at least one primary electrode (11) arranged on the stator (2) and extending in a direction of motion (x), and further comprising at least one secondary electrode (12) arranged on the shuttle (Tn), the at least one secondary electrode (12) facing the at least one primary electrode (11) and arranged in a normal direction (z) opposite to the at least one primary electrode (11), wherein the at least one primary electrode (11) and the at least one secondary electrode (12) are separated in the normal direction (z) by a power transfer air gap (13), the power transfer air gap having a power transfer air gap distance (T), wherein the power transfer air gap (13) extends in the direction of motion (x) and in a transverse direction (y), wherein the at least one primary electrode (11) and the at least one secondary electrode (12) form a power transfer capacitor (C PT ), the power transfer capacitor having the power transfer air gap (13) as a dielectric for capacitive power transfer for transferring electrical energy from the stator (2) to the shuttle (Tn), characterized in that The motor air gap (6) and the power transmission air gap (13) are parallel and arranged adjacent to each other in the transverse direction (y).

2. The linear motor according to claim 1, wherein At least one primary electrode (11) is arranged on each side of the drive magnet (3) or the drive coil (4) on the stator (2) in the transverse direction (y), and is characterized in that at least one secondary electrode (12) is arranged on each side of the drive coil (4) or the drive magnet (3) on the shuttle (Tn) in the transverse direction (y), and is characterized in that the at least one primary electrode (11) on each side is coupled to the at least one secondary electrode (12) on each side to form in each case a power transfer capacitor (C PT ).

3. The linear motor according to claim 1, wherein Two primary electrodes (11) are arranged on one side of the drive magnet (3) or the drive coil (4) on the stator (2) in the transverse direction (y), characterized in that two secondary electrodes (12) are arranged on the same side as the primary electrodes (11) in the transverse direction (y), and characterized in that each of the primary electrodes (11) is coupled to one of the secondary electrodes (12) to form in each case a power transfer capacitor (C PT ).

4. The linear motor according to claim 2 or 3, characterized in that Power transfer capacitors (C PT ) are both used for capacitive power transfer in the capacitive power transfer arrangement (10).

5. The linear motor according to claim 2 or 3, characterized in that: The power transmission capacitor (C PT ) is used for capacitive power transfer, and the power transfer capacitor (C PT ) is connected to the second power transfer capacitor (C PT ) of the primary electrode (11) and a first data communication unit (25) connected to the second power transmission capacitor (C PT ) between the second data communication unit (26) of the secondary electrode (12).

6. The linear motor according to any one of claims 1 to 3, characterized in that An additional primary electrode (11a) is arranged on the stator (2) of the linear motor (1), and an additional secondary electrode (12a) is arranged on the at least one shuttle (Tn) of the linear motor (1), the additional primary electrode (11a) and the additional secondary electrode (12a) forming an additional power transmission capacitor (C PTa ), the additional power transfer capacitor is used for capacitive data communication between: connected to the additional power transfer capacitor (C PTa ) of the additional primary electrode (11a) and a first data communication unit (25) connected to the additional power transmission capacitor (C PTa ) of the second data communication unit (26) of the additional secondary electrode (12a).

7. The linear motor according to claim 6, wherein: The additional secondary electrode (12a) faces the additional primary electrode (11a) and is arranged opposite the additional secondary electrode (11a) in the normal direction (z), wherein the additional primary electrode (11a) and the additional secondary electrode (12a) are separated by an additional air gap (13a) having an additional air gap distance in the normal direction (z), wherein the additional air gap (13a) extends in the movement direction (x) and the transverse direction (y), wherein the additional primary electrode (11a) and the additional secondary electrode (12a) form the additional capacitor (C PTa ), the additional capacitor (C PTa ) has the additional air gap (13a) as a dielectric, and wherein the motor air gap (6) and the additional air gap (13a) are arranged parallel to and adjacent to each other in the transverse direction (y).

8. The linear motor according to any one of claims 1 to 3, characterized in that A power transfer capacitor (C) formed by at least one primary electrode (11) and associated at least one secondary electrode (12) PT ) is additionally used for capacitive power transfer between: connected to the power transfer capacitor (C PT ) of the at least one primary electrode (11) and a first data communication unit (25) connected to the power transmission capacitor (C PT ) of the at least one secondary electrode (12).

9. A linear motor according to any one of claims 1 to 8, wherein the linear motor is provided with a capacitive power transmission arrangement (10) on both sides of the at least one shuttle (Tn) in the normal direction (z), and a stator (2) is provided on both sides of the at least one shuttle (Tn) in the normal direction (z).

10. The linear motor according to any one of claims 1 to 9, characterized in that The stator (2) comprises at least one curved portion, in which the stator (2) is curved around the normal direction (z).

11. The linear motor according to any one of claims 1 to 9, characterized in that The stator (2) comprises at least one bend in which the stator (2) is bent around the transverse direction (y).

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