Non-contact power transfer and power plant therefor

Abstract

A non-contact electric motion device in which electric power is non-contact provided from a stationary part to a moving part, said non-contact electric motion device comprising a stator, said stator comprising in cross section a magnetizable outer wall, said magnetizable outer wall enclosing a conductor and a hollow space, said magnetizable outer wall having a discontinuity forming an air gap, said stator and hollow space forming in longitudinal section a track. A moving part having a shoe or slider mounted within said hollow space to travel along said track, said mover non-contact filling the air gap at any given position as it passes. With the air gap closed a magnetic circuit is formed through said magnetizable outer wall and through said shoe or slider. Said mover has a coil in which current can be induced from said closed magnetic circuit.

Description

[0001] Related Applications

[0002] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62 / 982,085, filed February 27, 2020, the entire contents of which are incorporated herein by reference.

[0003] TECHNICAL FIELD AND BACKGROUND

[0004] The present invention relates generally to systems for delivering electrical power from a power source to an electrical load, particularly where there is relative motion between the power source and the load, and more particularly to an improved non-contact power delivery system for a power device, e.g., where the motion is linear rather than rotational, and further where precise motion is required.

[0005] Linear motion electrical systems are particularly useful in industrial automation systems. Such systems typically include a mobile element for conveying product components to one or more stations; at each station, a particular manufacturing process is applied to the product part. Modern automation systems use very fast and precise delivery systems in order to reduce the manufacturing and delivery time to the minimum achievable. For this purpose, very precise positioning systems are used. The product components to be processed are placed on a mobile carriage driven by the positioning system.

[0006] It is often necessary to have electrical power available on the mobile carriage for the operation of various sensors and actuators. In a first example, the mobile carriage is mounted on a linear motor that is part of a track, or is moved by a motor fixed on the carriage. In another example, a position encoder is needed to control the position of the carriage, and the position encoder and / or the carriage typically need a power supply. In another example, a rotary stage can be needed to orient the product components in the desired direction, so there is both rotational and linear motion.

[0007] In order to provide electrical power to the mobile carriage, flexible cables are typically used that can be configured in a cable chain. These cable assemblies can cause vibrations when high speed movement is needed, negatively affecting the movement of the carriage and potentially causing malfunctions. In some systems, sliding brushes are used to transfer electrical power. The brushes have a limited lifetime and generate electrical noise, limiting the use of brushes in relatively low speed systems.

[0008] Cable chains and brushes can increase the cost and reduce the reliability of the system. It is therefore desirable to provide a system that is capable of providing electrical power on a mobile carriage that is non-contact and does not require brushes or flexible moving cables.

[0009] Divan et al.'s patent 5341280 discloses a non-contact power transmission system using a frictionless and non-moving flexible cable. A high-intensity alternating current flows in a stationary conductor, and a magnetic core is fixed to several sliding members of a moving element, which slides along the stationary conductor via these members, thereby harvesting power through induction. A disadvantage of this solution is the relatively high weight of the magnetic core used for energy harvesting and the reduced maximum achievable acceleration of the support. Summary of the Invention

[0010] The system according to this embodiment includes a stator and at least one mover.

[0011] In the stator, a long hollow profile of ferromagnetic material is arranged along a desired linear path. The linear path can be any closed or open shape. The long profile cross-section preferably has a rectangular shape with an opening on the upper side, preferably in the middle. Two electrical conductors with significant cross-sectional dimensions extend within the hollow profile on either side of the opening. High-intensity alternating current (AC) flows in opposite directions or phases in these two conductors.

[0012] The mover (movable along the path) comprises a core made of ferromagnetic material, around which a coil is wound. The core shape is inserted into the contour opening and slides along the path without contacting the stator contour. As the mover slides along the path, a small air gap between the core and the plurality of stator conductors closes two magnetic circuits on either side of the core. Magnetic flux induced in these magnetic circuits passes through the mover coil in the core and induces electricity in the mover coil. Electricity can then be obtained on the mover even without electrical contact between the mover and the stator.

[0013] According to several embodiments of the present invention, a non-contact electrokinetic device can be provided, wherein electricity is supplied non-contactly from a stationary component to a moving component, the device comprising:

[0014] A stator, the stator including a magnetizable outer wall in cross-section, the magnetizable outer wall surrounding at least two conductors and a hollow space, the magnetizable outer wall having a discontinuity forming at least one air gap, the discontinuity dividing the stator into two stator halves, the stator and the hollow space forming a track in longitudinal section;

[0015] A mover having a first portion configured to be fitted within the hollow space to travel along the track, the mover substantially closing the air gap at any given position as it passes through, thereby closing the air gap and forming a plurality of magnetic circuits through the magnetizable outer wall in each of the stator halves and the first portion, the mover including a coil in which current can be induced from the closed plurality of magnetic circuits.

[0016] In one embodiment, the at least two conductors are located in each of the stator halves, and the plurality of conductors are configured to deliver alternating current in opposite phases.

[0017] In one embodiment, the mover is configured to move along the stator to several consecutive positions along the stator to form closed magnetic circuits, with open magnetic circuits present at other positions among the several positions.

[0018] In one embodiment, a length of the air gap extends longitudinally along the stator.

[0019] In one embodiment, the height of the air gap is a thickness of the magnetizable outer wall.

[0020] In one embodiment, the magnetic circuit includes two magnetic circuits and two air gaps, each magnetic circuit extending around a half of the stator, then reaching a first portion of the mover through a first of the two air gaps, and then returning to the half of the stator through a second of the two air gaps, the mover filling the two air gaps at a current position of the mover.

[0021] In one embodiment, the mover includes at least one wheel, or one wheel and one slider, or two wheels or two sliders, or more than two wheels, or other combinations of wheels and sliders.

[0022] In one embodiment, the mover includes a motor powered by an induced current in the coil.

[0023] In one embodiment, multiple movers are inserted into a single stator.

[0024] In one embodiment, each mover includes several sensors for motion or position, and is wirelessly controlled from a central controller to move along the stator based on feedback from the sensors.

[0025] In one embodiment, the stator is a gantry bridge, and the mover is mounted on the gantry bridge.

[0026] According to a second aspect of the invention, a non-contact electrokinetic device is provided, the non-contact electrokinetic device comprising a track and a mover, the track being hollow and having an open gap, the mover having a shoe portion adapted within the hollow and a neck extending through the open gap, the mover being configured to travel along the track, the track surrounding at least one current-carrying conductor and being magnetizable, the mover also being magnetizable and closing the open gap when forming a magnetic circuit through the shoe portion, the mover further comprising a coil surrounding the shoe portion for inducing current from the magnetic circuit, thereby providing onboard power to the moving part without contact.

[0027] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While methods and materials similar to or equivalent to those described herein may be used in the practice or testing of embodiments of the invention, the exemplary methods and / or materials described below shall be superseded by the patent specification (including definitions) in case of any conflict. Furthermore, the materials, methods, and examples are illustrative only and are not necessarily restrictive. Attached Figure Description

[0028] Brief Description of Several Views Some embodiments of the present invention are described herein by way of example only with reference to the accompanying drawings.

[0029] Please now refer specifically to the accompanying drawings. It should be emphasized that the details shown are exemplary and are used for illustrative discussion of embodiments of the invention. In this respect, the accompanying drawings... Figure One The description provided makes it clear to those skilled in the art how to implement embodiments of the invention.

[0030] In the diagram:

[0031] Figure 1 The prior art patent number 5341280 by Divan et al. is shown. Figure 4 For reference only;

[0032] Figure 2 This is a simplified schematic perspective view according to an embodiment of the present invention;

[0033] Figure 3 yes Figure 2 The embodiments described herein are by Figure 2 A simplified cross-sectional view in the plane defined by line A;

[0034] Figure 4 yes Figure 2 The embodiments described herein are by Figure 2 A simplified cross-sectional view in the plane defined by line B;

[0035] Figure 5This is a simplified schematic diagram of a multi-bracket system according to several embodiments of the present invention, wherein multiple brackets are located on a closed-loop stator and harvest non-contact power;

[0036] Figure 6 This is a simplified schematic cross-sectional view of a transformer for driving high current intensity into said plurality of stator conductors according to several embodiments of the present invention;

[0037] Figure 7 This is a simplified schematic diagram showing how to use a high-power driver to feed current into... Figure 6 The primary side of the transformer is shown, and a method for feeding high-intensity current into the stator conductors through the secondary side of the transformer is also shown.

[0038] Figure 8 This is a simplified schematic diagram of a common type of overhead crane that uses a moving cable;

[0039] Figure 9 This is a schematic diagram of a bridge crane implemented according to several embodiments of the present invention, which does not have a moving cable; and.

[0040] Figure 10 This is a simplified cross-sectional schematic diagram of a stator and a mover according to another embodiment of the present invention. Detailed Implementation

[0041] The present invention generally relates to several systems for transmitting electricity from a power source to an electrical load, particularly in cases where there is relative motion between the power source and the load, and more specifically to an improved contactless power transmission system, for example, wherein the motion is linear rather than rotational, or linear except for rotation, and further in cases where precise motion is required.

[0042] Several embodiments of this invention can provide a non-contact electrokinetic device in which electricity is supplied non-contactly from a stationary component to a moving component. A stator includes a magnetizable outer wall in cross-section, the magnetizable outer wall surrounding a conductor and a hollow space, the magnetizable outer wall having a discontinuity forming an air gap. The stator and the hollow space form a track in longitudinal section. The moving component has a shoe or slider mounted within the hollow space to travel along the track, the moving component filling the air gap non-contactly at any given location as it passes. The term "contactlessly filling" means that the material of the moving component fills the air gap, almost contacting the wall of the stator, but not actually making contact, thus leaving a smaller air gap. However, changing the aspect ratio of the air gap significantly reduces magnetic reluctance and forms a viable magnetic circuit. With the air gap effectively closed, the magnetic circuit is formed through the magnetizable outer wall and through the shoe-shaped fitting or slider. The mover has a coil in which current can be induced from the closed magnetic circuit.

[0043] To better understand some embodiments of the present invention, please first refer to... Figure 1 The structure and operation of the known device shown.

[0044] Figure 1 This illustrates the prior art described in US Patent 5341280 by Divan et al. A primary converter 38 drives current into the plurality of electrical conductors 40. The electrical conductors 40 are arranged along a movement path having a return portion. Two magnetic cores 56 and 58 surround the current conductors in both directions simultaneously, sliding along the path without contacting the conductors. Windings 52 are wound around the two magnetic cores, and power is available at the plurality of winding ends 46.

[0045] The magnetic core is fixed to the moving element. According to conventional design rules, the weight of the magnetic core is proportional to the electrical power supplied to the moving element. When a large amount of power is required, this design weight (as part of the weight of the moving element) limits the maximum acceleration.

[0046] When a long path is required, several conductor support structures must be used. These structures can be traversely moved among the cores, and air gaps must be provided within the cores to minimize these air gaps; these structures must be designed with a thin profile. Divan et al. proposed a design (patent US 5,341,280). Figure 7 and Figure 8 This results in relatively high costs and a relatively weak structure.

[0047] In Divan's embodiment, the electrical conductor 40 is exposed to open air. To achieve sufficient efficiency, a high frequency of current is required in the conductor 40. This high-intensity and high-frequency current operating in the open air would generate unwanted strong electrical radiation, which could interfere with other nearby equipment.

[0048] In several embodiments described below, a contactless power system (CPS) is described, in which the added weight on the mover is reduced, the overall structure can be simplified, and the amount of electrical radiation and thus the range of interference are minimized.

[0049] For clarity, the following description refers to a preferred orientation of the CPS, but the CPS can be oriented in any manner suitable for the desired operation.

[0050] Before explaining at least one embodiment of the present invention in detail, it should be understood that the application of the present invention is not necessarily limited to the details of the construction and / or configuration of the components and / or methods shown in the following description and / or drawings and / or examples. The present invention can be practiced or implemented in other embodiments or in various ways.

[0051] Please refer to Figure 2 A simplified perspective view of an embodiment of a contactless power system (CPS) according to the present invention is shown. The CPS 200 includes stators 201, 203a, 203b and at least one mover 202, 204, 205. The movers can slide along a defined desired path. The defined path can have a shape, such as a straight line, a curve, or a circle.

[0052] The stator comprises an elongated profile 201 of a preferably laminated magnetizable material (such as iron or electric steel). The elongated profile 201 has a rectangular hollow cross-section, wherein a hollow interior is enclosed within a plurality of walls and an opening or gap 206 on its upper surface, wherein the height of the gap is the thickness of the plurality of walls. The elongated profile 201 may extend along the entire movement path and define a track for movement. Figure 2 Only the short, straight portion of the stator is shown in the image. Figure 2 The diagram shows a straight line shape, but it must be understood that any curved or circular shape can be used to follow the desired path of the mover.

[0053] Within the stator, two large conductors 203a and 203b are arranged on several corresponding sides of the opening. Alternating current (AC) flows in opposite directions or phases in conductors 203a and 203b.

[0054] The mover includes a vertical portion or neck 204 and a horizontal portion 205, both made of a magnetic material, such as laminated electrical steel. A coil may be wound around the bottom of the vertical portion 204 to form a shoe 202. The mover slides along a path within the opening 206 of the elongated profile 201, wherein the shoe is contained within the stator.

[0055] Please refer to Figure 3 , Figure 2 A cross section of the CPS is shown in the figure. Figure 2 The plane defined by the dashed line A is shown in the view. In this view, it can be seen how the mover core assemblies 205 and 204 create two magnetic circuits 301a and 301b. The vertical portion of the magnetic core 204 (made of magnetic material) provides a path for magnetic flux. Magnetic circuit 303a operates in a high-permeability magnetic material, but not in several small air gaps 303a and 302 through which it must traversed to allow free movement within the stator. Symmetrically, magnetic circuit 303b is also arranged in a high-permeability magnetic material, except for the small air gaps 303b and 302. Current in conductor 203a leaves the cross-sectional plane and generates a counter-clockwise magnetic flux in magnetic circuit 301a. Symmetrically, current in conductor 203b enters the cross-sectional plane and generates a clockwise magnetic flux in magnetic circuit 301b.

[0056] Within the vertical portion 204 of the core, two magnetic fluxes travel in the same direction and induce a power source in the surrounding coil 202. Power can be obtained from the mover without electrical contact with the stator.

[0057] Please refer to now. Figure 4 ,This is Figure 2 Another cross-section of the CPS, this time in Figure 2 The plane defined by the dashed line B. The plane of the cross-section is obtained on a horizontal plane excluding the mover. For the efficiency of CPS, the inductance of the stator may be low. Figure 4As can be seen, the elongated profile 201 forms a magnetic circuit 401 around the two conductors 203a and 203b. However, the total current enclosed by the magnetic circuit 401 is zero because the currents running in the two conductors 203a and 203b are equal and opposite in direction or phase. Therefore, the magnetic flux in the circuit is zero, and the inductance of the circuit formed by the two conductors 203a and 203b is very low; thus, high currents can be driven in these conductors at relatively high frequencies, allowing a large amount of power to be transferred to the mover.

[0058] On the other hand, the magnetic circuit 401 forms a shield around the plurality of conductors 203a and 203b, so that virtually no magnetic field radiates to the outside of the CPS. This allows the CPS to be used near or in combination with other systems that are sensitive to electrical interference.

[0059] Please refer to now. Figure 5 , Figure 5 This is a simplified diagram of a multi-bracket system 500 that can be advantageously implemented using CPS according to several embodiments of the present invention.

[0060] CPS stator 501 includes a long profile (similar to profile 201 described above and having similar characteristics to...) Figure 2 Several conductors 203a and 203b (including several enclosed conductors) are arranged along a closed-loop path. Alternating current is driven in the stator conductors by a power supply 504. Five independent movers 501a to 501d are slidably inserted along the stator 501. Each mover slides along the track defined by the stator and may be guided by bearings or wheels (not shown). As described above, each mover collects power from the stator. Each mover is propelled by its own motor, symbolically shown as motors 503a to 503d, which are powered using the collected power. The mover motors can be of any type, rotary or linear. Each mover may also include a motor controller that controls the position of the mover, the controller also being powered by a CPS. In one example, the motor controller communicates wirelessly with a central controller, which then controls the position and speed of each mover.

[0061] Existing multi-carriage systems employ individual position control for each motor and utilize multiple actuators, each controlling a small portion of the stator. To control the movement of each carriage, a central controller activates several actuators on the portion of the stator closest to the carriage. However, these existing multi-carriage systems are very expensive and require highly complex software due to their large number of actuators. The CPS-powered multi-carriage system of this invention can be implemented at a much lower cost because the entire stator can be driven as a single unit.

[0062] To drive the required high-intensity AC current in the conductors 203a and 203b in the stator, a transformer can be used. Now please refer to Figure 6 The image shows a cross-section of such a transformer 600. The transformer 600 has a magnetic core 602. The magnetic core 602 forms two magnetic circuits 603a and 603b surrounding two open air volumes 604a and 604b. A primary-side coil 601 with N turns is wound around the middle portion of the magnetic core shared by the two magnetic circuits. The two conductors 203a and 203b of the CPS stator pass through the remaining space of the open air volumes 604a and 604b, respectively.

[0063] Please refer to now. Figure 7 The transformer 600 is shown in dashed lines. The plurality of conductors 203a and 203b are shown traversing the transformer, and their ends are connected by a connecting conductor 703 after traversing the transformer. A portion of the stator's elongated profile is shown as element symbol 704. At this portion, the two conductors 203a and 203b exit the elongated profile to traverse the transformer 600. After traversing the transformer 600, their ends 705a and 705b are electrically connected by a conductor 703.

[0064] The other ends of conductors 203a and 203b (shown as 706a and 706b respectively) are also electrically connected via conductor 702. Figure 7 In the diagram, these other ends are shown on the same portion of the stator 704. This is the case where the stator forms a closed path, as... Figure 5 As shown. Whenever the stator does not form a closed path, the connection 702 is applied to the plurality of ends of the plurality of conductors 203a and 203b.

[0065] Finally, the two conductors 203a and 203b connected at both ends form a single closed loop through the transformer 600. This closed loop constitutes one short-circuited turn of the secondary winding of the transformer 600. According to the transformer law, if current I flows in the N-turn primary winding 601, then current NxI flows in the one short-circuited secondary winding, thus entering the conductors 203a and 203b.

[0066] Therefore, high-intensity current can flow in the stator conductors 203a and 203b via transformer 600. This allows the use of a normally available AC power supply 701 to drive high-intensity current in the CPS stator conductors.

[0067] When a long path is required, the CPS stator can be divided into several parts, each with its own power supply, as shown above. Figure 6 and Figure 7 As stated above.

[0068] In another exemplary application, the CPS according to embodiments of the invention can be advantageously implemented in overhead cranes or gantry cranes, thereby eliminating the need for a moving cable.

[0069] exist Figure 8 The diagram illustrates a typical overhead crane found in factory settings. A beam 803 is fixed at both ends to two walls 801 and 802. A crane controller 807 includes wheels, gears, motors, and an electrical controller. The crane controller 807 can slide along the beam 803 via an electric motor 804. A hook 805, suspended from the crane body, is provided to secure several objects to be handled. The vertical position of the hook is controlled by a motor 809. A manual controller 808 is used for manual operation of the crane. A flexible cable 806 is used to connect electricity to the controller and the motors.

[0070] like Figure 8 As schematically shown, the cable 806 is typically bent or coiled, and the coil may be fixed to several sliders that can slide along the beam to allow free movement of the crane controller. Whenever the crane is used intensively, the movement of the cable 806 may suffer increased friction due to dirt buildup on the sliding elements. Furthermore, the folding and unfolding of the cable 806 due to repeated use of the crane can lead to cable failure, resulting in damage, inoperability, and dangerous operation of the crane.

[0071] Figure 9 The diagram schematically illustrates crane embodiments using CPS according to several embodiments of the present invention. The bridge crane has... Figure 8 The same components are shown, except that cable 806 is not used. Beam 903 includes a CPS stator according to several embodiments of the invention, and a current generator 906 is added to drive current in the CPS conductors. The crane controller is powered by the CPS and controls the movement of the crane; therefore, the CPS embodiment provides the crane with more reliable and safer operability. Furthermore, maintenance costs are reduced.

[0072] It will be apparent to those skilled in the art that many other applications of CPS can be envisioned, in which electrical power is transferred to moving elements without contact.

[0073] Please refer to now. Figure 10 The diagram illustrates a schematic cross-sectional view of an alternative embodiment of the CPS according to the invention. The CPS 1000 includes a stator 1003 and at least one mover 1001. The mover 1001 can travel on the stator 1003 via wheels 1002a-1002c. The stator extends in a direction perpendicular to the cross-section, defining a motion path. The path can be of any curve type.

[0074] The stator includes two elongated profiles 1004a-1004b made of a magnetizable material, such as iron or electrical steel, preferably laminated. The elongated profiles 1004a-1004b respectively form rectangular hollow cavities 1006a and 1006b. These two elongated profiles 1004a and 1004b are positioned within the stator 1003 such that their cavities 1006a and 1006b face each other and are spaced apart to allow movement of a short profile portion 1008 fixed to the mover. The elongated profiles 1006a and 1006b extend along the entire movement path of the mover, while the short profile portion 1008 fixed to the mover extends along a short path within the range of the mover.

[0075] Inside the stator, two large conductors 1005a and 1005b are respectively disposed within the plurality of cavities 1006a and 1006b. Alternating current flows in opposite phases within conductors 1005a and 1005b.

[0076] A short profile portion 1008, made of a preferably laminated magnetizable material, is attached to the mover. The two long profiles 1004a and 1004b and the profile portion 1008 are shaped to provide a large area of ​​several narrow air gaps 1007a-1007d.

[0077] The coil 1009 is wound around the middle portion of the outline portion 2008.

[0078] according to Figure 10 The functionality of the CPS in the embodiment is described below.

[0079] In the absence of the mover, the two elongated profiles 1004a and 1004b form a magnetic circuit 1011 (square dashed line), which has very high magnetic reluctance due to the large spacing between them. Furthermore, the two currents operating in the conductors 1005a and 1005b have opposite directions, or opposite phases with respect to AC, and they induce magnetic fluxes in opposite directions in the magnetic circuit 1011, resulting in very low inductance of the stator 103 and negligible electromagnetic radiation emitted outside the stator.

[0080] At several locations where the moving part fills the gap, two magnetic circuits 1010a-1010b are formed around each conductor 1005a and 1005b. Two magnetic fluxes induced by the current flow in the same direction within coil 1009, inducing electrical current in coil 1008. Therefore, there is available power on the mover. For example, an electric motor can be mounted on the mover to drive it. Other electrical or electronic devices can be used in the mover, such as encoders, digital communication interfaces, digital input / output, etc.

[0081] The terms “including,” “comprising,” “having,” and their conjugates mean “including but not limited to.”

[0082] The term "including" means "including and limited to".

[0083] As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” include the plural.

[0084] It should be understood that, for clarity, certain features of the invention described in the context of a single embodiment may also be provided in combination in a single embodiment, and this description is to be interpreted as if such embodiments were explicitly set forth herein. Conversely, for brevity, various features of the invention described in the context of a single embodiment may also be provided individually or in any suitable sub-combination, or may be adapted as modifications to any other described embodiment of the invention, and this description is to be interpreted as meaning that certain features described in the context of various embodiments, where sub-combinations and modifications are explicitly set forth herein, are not considered essential features of those embodiments unless the embodiments would be inoperable without these elements.

[0085] Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. Therefore, it is intended to encompass all such alternatives, modifications, and variations falling within the spirit and broad scope of the appended claims.

[0086] All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety, to the same extent that each individual publication, patent, or patent application is specifically and individually indicated to be incorporated herein by reference. Furthermore, any reference or designation of any reference in this application should not be construed as an admission that such reference is prior art to the invention. The use of section headings should not be construed as necessarily limiting. Additionally, any priority documents of this application are incorporated herein by reference in their entirety.

Claims

1. A non-contact electrokinetic device, wherein electricity is supplied non-contactly from a stationary component to a moving component, characterized in that, The device includes: A stator, the stator including a magnetizable outer wall in cross-section, the magnetizable outer wall surrounding at least two conductors and a hollow space, the magnetizable outer wall having a discontinuity forming at least one air gap, the discontinuity dividing the stator into two stator halves, the stator and the hollow space forming a track in longitudinal section, the at least two conductors respectively located in each of the stator halves, the two conductors being configured to deliver alternating current in opposite directions; A mover having a vertical portion and a horizontal portion, both made of magnetic material, the vertical portion being configured to be fitted within the hollow space to travel along the track, the mover substantially closing the air gap at any given position as it passes, thereby closing the air gap and forming two magnetic circuits through the magnetizable outer wall in each of the stator halves, the vertical portion, and the horizontal portion, respectively. The mover includes a coil in which current can be induced from the two closed magnetic circuits, the coil being wound around a bottom of the vertical portion to form a boot. One of the two conductors generates a first magnetic flux in the corresponding magnetic circuit that runs counterclockwise, and the other of the two conductors generates a second magnetic flux in the corresponding magnetic circuit that runs clockwise. In the vertical portion, the first magnetic flux and the second magnetic flux run in the same direction and induce a current in the coil.

2. The non-contact electrokinetic device as described in claim 1, characterized in that, The mover is configured to move along the stator to several consecutive positions along the stator to form closed magnetic circuits, while open magnetic circuits exist at other positions.

3. The non-contact electrokinetic device as described in any one of claims 1 to 2, characterized in that, One length of the air gap extends longitudinally along the stator.

4. The non-contact electrokinetic device as described in claim 3, characterized in that, The height of the air gap is equal to the thickness of the magnetizable outer wall.

5. The non-contact electrokinetic device as described in claim 1, characterized in that, The plurality of magnetic circuits includes two magnetic circuits and two air gaps. Each magnetic circuit extends around a half of the stator, then reaches the vertical portion of the mover through a first of the two air gaps, and then returns to the half of the stator through a second of the two air gaps. The mover fills the two air gaps at a current position of the mover.

6. The non-contact electrokinetic device as described in claim 1, characterized in that, The moving part includes at least one wheel.

7. The non-contact electrokinetic device as described in claim 1, characterized in that, The mover includes a motor powered by the current induced in the coil.

8. The non-contact electrokinetic device as described in claim 1, characterized in that, Multiple movers are inserted into a single stator.

9. The non-contact electrokinetic device as described in claim 8, characterized in that, Each mover includes several sensors for motion or position, and is wirelessly controlled from a central controller to move along the stator based on feedback from the sensors.

10. The non-contact electrokinetic device as described in claim 1, characterized in that, The stator is a gantry bridge, and the mover is mounted on the gantry bridge.

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