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EP-3729619-B1 - ELECTRIC MOTOR

EP3729619B1EP 3729619 B1EP3729619 B1EP 3729619B1EP-3729619-B1

Inventors

  • HAASE, THOMAS
  • SERRER, Tobias

Dates

Publication Date
20260513
Application Date
20181206

Claims (14)

  1. Electric motor, having: - at least one magnetic track (3), which has a plurality of magnetic elements (31) arranged in a longitudinal direction or a ring shape, and - at least one coil arrangement (5), which includes a carrier, which is electrically and magnetically substantially non-conductive with respect to the magnetic track, configured in such a way that the coil arrangement and the magnetic track are able to move in a guided manner relative to one another, and which includes at least one group of three conductive flat coils (51, 53, 55), wherein each of the three flat coils is connected to a phase of a three-phase power supply and wherein the conductor tracks (51.1, 51.2, 53.1, 53.2, 55.1, 55.2) of the three flat coils of the or each group are arranged interleaved or overlapping in a first and second conductor layer of the carrier, which are electrically insulated from each other by an insulating intermediate layer, in such a way that parts of the conductor path of each of the three flat coils are designed one above the other and connected in parallel in the first and second conductor layer and two of the three overlapping flat coils have crossover regions in which the conductor tracks of the first flat coil only run in the first and the conductor tracks of the second flat coil only run in the second conductor layer of the carrier, characterised in that the magnetic track with the magnetic elements and the flat coils of the coil arrangement are dimensioned in coordination with one another such that the crossover regions of the flat coils lie outside the projection of the magnetic elements onto the coil arrangement.
  2. Electric motor according to Claim 1, wherein the magnetic track has a plurality of magnetic elements (31) in a Halbach array configuration.
  3. Electric motor according to Claim 1 or 2, wherein the magnetic track (3) is associated with a stator and the coil arrangement (5) is associated with a rotor of the electric motor and in particular the stator has substantially the shape of an elongated or annular closed U-profile or rectangle and the rotor is designed to be plate-shaped or strip-shaped so as to match the shape of the stator in such a way that it can move inside the U-profile or rectangle.
  4. Electric motor according to one of the preceding claims, wherein the coil arrangement (5) comprises two or more groups of three flat coils (51, 53, 55) respectively connected to a phase of the three-phase power supply, which are arranged consecutively in a longitudinal direction or in a ring shape on or in the carrier.
  5. Electric motor according to one of the preceding claims, wherein the carrier is designed as a multi-layer printed circuit board and respectively exactly two adjacent conductor layers of the multi-layer printed circuit board are structured to form the three associated, overlapping flat coils (51, 53, 55), wherein in the crossover regions, the transitions of a flat coil path from the first to the second conductor layer and vice versa are formed by means of vertical vias.
  6. Electric motor according to one of the preceding claims, wherein the carrier is designed as a multi-layer printed circuit board with 2m conductor layers (m≥2), in which each of the three associated overlapping flat coils (51, 53, 55) of a group comprises 2 to m substantially identical conductor tracks (51.1, 51.2, 53.1, 53.2, 55.1, 55.2) connected in series, wherein the electrical connections between the conductor tracks connected in series are designed by means of vertical vias through the multi-layer printed circuit board.
  7. Electric motor according to Claim 5 or 6, wherein each of the flat coils (51, 53, 55) has a small connection and via region, which is arranged directly on a short side of the respective flat coil and in which vias are placed for connecting the conductor tracks arranged one above the other and connected in series and for the external connection of the flat coil, wherein a dimension of the connection and via region, in particular its length in a longitudinal direction of an elongated flat coil, is less than 10 %, in particular less than 5 %, of the corresponding dimension of the flat coil.
  8. Electric motor according to Claim 7, wherein the small connection and via region is respectively positioned near a corner of a polygonal flat coil configuration and comprises a substantially hook-shaped conductor section.
  9. Electric motor according to one of Claims 5 to 8, wherein the associated three flat coils (51, 53, 55) formed by structuring the respective two conductor layers of the multi-layer printed circuit board are configured to be substantially rectangular and are arranged interleaved and overlapping in such a way that the long sides of the three flat coils run respectively parallel to one another in the first and second conductor layer, and respectively the largest part of the conductor path of a corresponding side of the two other flat coils is arranged within the rectangle of one of the three flat coils.
  10. Electric motor according to one of Claims 5 to 8, wherein the associated three flat coils (51, 53, 55) formed by structuring the respective two conductor layers of the multi-layer printed circuit board are configured to be substantially trapezoidal and are arranged interleaved and overlapping in such a way that the non-parallel sides of the trapezoidal shapes of the three flat coils run respectively parallel to one another in the first and second conductor layer, and respectively the largest part of the conductor path of a corresponding side of the two other flat coils is arranged within the trapezoid of one of the three flat coils.
  11. Electric motor according to Claim 9 or 10, wherein all conductors of all three flat coils (51, 53, 55) respectively have the same distance to one another on the long sides of the rectangular conductor configuration or on the non-parallel sides of the trapezoidal conductor configuration and there is no greater distance region within the associated three flat coils.
  12. Electric motor according to Claim 11, wherein the distance between the adjacent conductor tracks (51.1, 51.2, 53.1, 53.2, 55.1, 55.2) is smaller than their width, in particular smaller than half their width.
  13. Electric motor according to one of Claims 9 to 12, wherein in the substantially rectangular or trapezoidal conductor path of the flat coils (51, 53, 55), respectively one virtual corner of the rectangle or trapezoid is replaced by conductor sections running obliquely to the adjacent sides.
  14. Electric motor according to one of the preceding claims, wherein at least part of the conductor paths are widened at least in part of the crossover regions and, due to the current load reduced by the widening, act as heat sinks for the respective flat coil (51, 53, 55).

Description

The invention relates to an electric motor with a magnetic track comprising a plurality of magnetic elements arranged in a longitudinal direction, in particular in a Halbach array configuration, and a coil arrangement comprising a carrier configured in such a way that the coil arrangement is capable of guided movement relative to the stator magnetic track and comprising at least one group of three conductive flat coils. Linear actuators have been gaining increasing importance in a wide variety of industrial applications for decades. They are therefore the subject of extensive development work, a significant portion of which aims at the most efficient and thus cost-effective manufacturing possible while ensuring high performance. Linear motors typically comprise several coils or coil sets arranged adjacent to one another, and a plurality of magnets arranged with their north and south poles alternating along a magnetic track. Successive excitation of the coils by an electric current causes the coil arrangement to move relative to the magnet arrangement, i.e., along the magnetic track. While the aforementioned coils are typically constructed from wound wires, efforts have been underway for several years to develop a simpler manufacturing method using so-called flat coils. These developments are driven in particular by the need for smaller and even miniaturized linear motors, where the conventional method of coil manufacturing becomes increasingly uneconomical as the dimensions decrease and could ultimately represent a limiting factor for the use of linear actuators. A linear motor with this novel design is described in the US 6,664,664 B2 Here, flat coils are arranged side by side on an elongated, non-conductive substrate and connected to the different phases of a multi-phase power supply. The publication also describes the multi-layered design of each flat coil by means of essentially identical conductor paths arranged one above the other in several conductor layers of a multi-layer printed circuit board. The geometric configuration of these flat coils is that of a rectangle, and connection areas are arranged outside each rectangle, encompassing vias through the multi-layer printed circuit board. A multi-layered flat coil arrangement is also available from the WO 2017/080859 A1 The applicant is aware of this technology as a component of a planar positioning device or a positioning table. Here, too, a multi-layer printed circuit board is used for the technical implementation, wherein several related flat coils are implemented as conductor traces of a first conductor layer of the multi-layer printed circuit board for most of their length, and crossing areas of the flat coils essentially run in a second conductor layer of the multi-layer printed circuit board. Further relevant prior art includes the following: US 2002/185919 A1 and the EP 0 133 571 A2 . The invention is based on the objective of providing an improved electric motor which is characterized, among other things, by increased efficiency in compact dimensions and can be manufactured efficiently and cost-effectively. This problem is solved by an electric motor having the features of claim 1. Advantageous further developments of the inventive concept are the subject of the dependent claims. The invention includes the concept of nesting several (in practice, specifically three) flat coils, each connected to one of the individual phases of a multi-phase power supply (specifically, a three-phase network), within one another on a non-conductive substrate to optimally utilize the available conductor area of a first and second conductor plane. This necessarily results in certain conductor sections of the multiple flat coils overlapping or crossing each other. The aforementioned nesting is geometrically determined with respect to the two available conductor planes such that at any given point, conductor traces from at most two of the three flat coils lie one above the other. In those areas, which are subsequently referred to as crossing areas, the The conductors of one of the two flat coils are formed in only one of the two conductor planes, while the (crossing or overlapping) conductors of the other flat coil run in the other of the two conductor planes. However, in all those sections of the nested flat coils where no conductors of two coils cross, both conductor planes are used for the overlapping conductors of one of the three flat coils. Both the concept of nesting (instead of placing side by side) the flat coils belonging to the same group within the multi-phase supply scheme and the use of large areas of both conductor planes above and below the insulating intermediate layer for the execution of the conductor traces of each of the flat coils lead to a significantly improved utilization of the available conductor area, and the concept also offers the possibility of a much more compact design of the flat coil group as a whole and thus possibly also of the