METHOD FOR OPERATING AN ELECTRIC MACHINE AND ELECTRIC MACHINES

Abstract

In a method for operating an electric machine with at least two coils and a magnetizable, movable core such as an armature or a rotor, a current of a constant average value is applied from a direct current source at the coils in such a way that the device is operated in the magnetic saturation range of the core. More particularly, one linear and one rotational actuator is proposed for such an operating mode.

Claims

1-25. (canceled)

26. A method for operating an electric machine with at least two coils and a magnetizable movable core such as an armature or a rotor, which comprises the steps of: applying a current of a constant average value of a DC voltage source to the at least two coils such that an operation of the electric machine takes place in a magnetic saturation region of the magnetizable movable core.

27. The method according to claim 26, wherein saturation is more than 103 A/cm.

28. The method according to claim 26, wherein the magnetizable movable core contains soft iron or at least one stack of sheets.

29. The method according to claim 26, wherein an operating voltage is lower than a contact voltage.

30. The method according to claim 26, which further comprises cooling the at least two coils directly by a cooling liquid.

31. The method according to claim 26, wherein the magnetizable movable core performs a rotational or translational movement when the current is applied to the at least two coils.

32. A coil, comprising: an insulating layer; and windings each formed from a two-dimensionally extending conductive foil, said windings being separated by said insulating layer.

33. The coil according to claim 32, wherein said two-dimensionally extending conductive film and said insulating layer are formed integrally.

34. A coil configuration, comprising: coils each having an insulating layer and windings of a two-dimensionally extending conductive foil, said windings being separated by said insulating layer, said coils being conically shaped to form a circular ring.

35. An electric actuator, comprising: a core formed by at least one magnetizable laminated core part on a central, non-magnetizable shaft.

36. The actuator according to claim 35, further comprising: shaft-fixed head plates; a stack of sheets disposed between said shaft-fixed head plates; and spacer sleeves being guided on said central, non-magnetizable shaft, and which clamp said stack of sheets between said shaft-fixed head plates and/or space several of said stacks of sheets.

37. The actuator according to claim 36, further comprising a plurality of coils; and wherein said core moves with said stack of sheets through or past said plurality of coils which are immediately adjacent or equally spaced, or in that said stack of sheets of said core forms vanes which move between said plurality of coils forming two coaxial circular rings.

38. The actuator according to claim 37, further comprising a coil arrangement being rectangular in shape with a central through-opening formed therein for said core.

39. The actuator according to claim 38, wherein: said coil arrangement is one of a plurality of coil arrangements, each of said coil arrangements has on each corner side an opening formed therein and through each of said openings a mounting shaft passes, each coil arrangement has spacer sleeves being guided on each of said mounting shafts which space said coil arrangements and/or clamp them between two said shaft-fixed head plates fixed to said central, non-magnetizable shaft.

40. The actuator according to claim 39, further comprising a top plate, said top plate having openings formed therein and through said openings said spacer sleeves of said coil arrangements formed as guides pass.

41. The actuator according to claim 37, wherein said coils contain a winding core and at least one of said coils is disposed annularly around said winding core.

42. An electrical machine, comprising: a parallel connection of a plurality of actuators, each of said actuators having a core formed by at least one magnetizable laminated core part on a central, non-magnetizable shaft.

43. The electrical machine according to claim 42, further comprising a common head plate, each said core is connected on both sides to said common head plate.

44. A rotatory actuator, comprising: coils of a stator being of a conical design and assembled to form a circular coil configuration.

45. The rotatory actuator according to claim 44, further comprising: a rotor with a shaft; and at least two coil assemblies which with respect to said shaft of said rotor, are axially spaced and aligned.

46. The rotatory actuator according to claim 44, wherein said circular coil configuration has a radially inner positioning ring for said coils.

47. The rotatory actuator according to claim 44, further comprising mounting shafts; further comprising spacer sleeves; further comprising two head plates; and wherein said circular coil configuration is one of a plurality of coil configurations, each of said coil configurations have a radially outer positioning ring for said coils, said radially outer positioning ring has openings formed therein for receiving said mounting shafts, said spacer sleeves are guided on said mounting shafts, which space said coil configurations and clamp them between said two head plates fixed to said mounting shafts.

48. The rotatory actuator according to claim 44, wherein said circular coil configuration is one of a plurality of coil configurations; and further comprising a non-magnetizable rotor shaft with at least one magnetizable laminated core with radially arranged vanes which dip into a space between two said coil configurations.

49. The rotatory actuator according to claim 48, further comprising: head plates; and spacer sleeves being guided on said non-magnetizable rotor shaft, which clamp said magnetizable laminated core between said head plates fixed to said non-magnetizable rotor shaft and/or space several laminated cores.

50. A machine or actuator, comprising: a device selected from the group consisting of: a parallel connection of a plurality of actuators, each of said actuators having a first core formed by at least one magnetizable laminated core part on a central, non-magnetizable shaft; and a second core formed by said at least one magnetizable laminated core part on said central, non-magnetizable shaft; and a non-magnetizable housing.

Description

[0031] The essence of the invention is explained in more detail with reference to the drawing, in which only design examples are shown.

[0032] In the drawing shows:

[0033] FIG. 1: partially cut a core or an armature for a linear actuator,

[0034] FIG. 2: a frontal view according to the arrow II in FIG. 1,

[0035] FIG. 3: in a top view the bearing of several armature,

[0036] FIG. 4: the arrangement of coils with respect to the armatures in FIG. 3,

[0037] FIG. 5: a cut according to the line V, V in FIG. 4,

[0038] FIG. 6: a cut according to the line VI, VI in FIG. 4,

[0039] FIG. 7: a view of a coil corresponding to FIG. 5,

[0040] FIG. 8: a cut according to the line VIII, VIII in FIG. 7,

[0041] FIG. 9: a cut according to the line IX, IX in FIG. 7,

[0042] FIG. 10: a spacer,

[0043] FIG. 11: a view according to arrow XI in FIG. 10,

[0044] FIG. 12: a variant of a coil arrangement,

[0045] FIG. 13: a tapered coil arrangement,

[0046] FIG. 14: a section parallel to the drawing plane of FIG. 13,

[0047] FIG. 15: a section according to line XV, XV in FIG. 16,

[0048] FIG. 16: section of a stator of a rotary actuator,

[0049] FIG. 17: a rotor as the core of a rotary actuator,

[0050] FIG. 18: a rotor as the core of a rotary actuator in section.

[0051] A Linear Actuator

[0052] FIG. 1 shows a core or armature 1 cut in the left half of the picture for a linear movement in the axial direction. In this design example, the armature 1 is provided with two stack of sheets 2,3 on a non-magnetic central shaft 4. The stacks of sheets 2,3 consisting of a plurality of, for example, radially oriented transformer sheets, dynamo sheets III or IV or the like of a typical material thickness of 0.5 mm have, like the shaft 4, a circular cross-section, cf. FIG. 2. The magnetic saturation of such sheets should be as high as possible, currently up to 2.3 104 Gauss, in order to minimize conduction loss. The stacks of sheets 2,3 are spaced from each other by a spacer sleeve 5 on the shaft 4. The sheet packs 2,3 are spaced from each other by a spacer sleeve 5 on the shaft 4. The non-magnetic spacer sleeves 5 to 7 and the two plate packs 2,3 are braced between two head plates 8,9, which are fixed to the shaft 4 with screws 10,11.

[0053] Such an armature 1, in conjunction with coils setting it in motion, forms a module, as it were, which can be connected in parallel and/or in series with further modules.

[0054] Thus, with reference to FIGS. 3 to 11, the structure of a translational actuator 14 with four parallel-connected armatures 15 to 18, which are rigidly connected to each other via common head plates 19,20, is further explained. As in the previous design example shown in FIG. 1, two stacks of sheets 24, 25 are clamped between the head plates 19, 20 and each armature 15 to 18 between spacer sleeves 21 to 23. Essentially, the actuator 14 is symmetrical with respect to a horizontal center plane 26,27 and a vertical center plane 27.

[0055] The armatures 15 to 18 held by the head plates 19,20 are linearly displaceable within a cage 28 of preferably a magnetic material according to the double arrow. In the design example, the cage 28 has sixteen mounting bars 31 of the same type between two side elements 29,30. Four mounting rods 31 each pass through four coil arrangements 32 to 35 associated with an armature 15, see also FIG. 5. By means of three spacer sleeves 36 to 38 guided on the shaft 31, the four coil arrangements 32 to 35 are equally spaced in the direction of movement of the armature 15. The air gap between the coil arrangements 32 to 35 and the sheet metal packages 24, 25 of the armature 15 runs between 0.3 and 0.5 mm.

[0056] The coil arrangements 32 to 35 with spacer sleeves 36 to 38 arranged between them are braced between the side cheeks 29,30 via two outer spacer sleeves 39,40. The coil arrangements 32 to 35 must be designed to be correspondingly pressure-resistant.

[0057] The four anchors 15 to 18 are connected to each other by the common head plates 19,20, cf. FIGS. 5 and 6. The head plates 19,20 are provided with openings in which plain bearings 43,44 are embedded. These plain bearings 43,44 are here exemplarily guided on the inner spacer sleeves 45,46. Alternative bearing options are possible without any problems.

[0058] Referring to FIGS. 7 through 11, the structure of a pressure-resistant coil assembly 50 is further explained. The coil assembly 50 has a central aperture 51 for an armature 15 to 18. Four further apertures 52 in the corner regions of the square coil arrangement 50 are used for the passage of mounting rods 31.

[0059] The exemplary 100 to 250 windings of the coil 53, for example made of a copper-coated Teflon film with a PFTE layer of a material thickness of 10 μm and a material thickness of the Cu layer of 30 μm on a coil carrier 54, a Teflon film, a self-adhesive Teflon fabric or the like, whose material thickness of approx. 0.125 mm is clearly shown exaggerated in the drawing, are trapped between two non-electrically conductive or to the side supports 55,56.

[0060] Coil arrangements 50 as shown in FIG. 7 are also braced between two spacer sleeves and must therefore have sufficient pressure stability. This is ensured by spacers 57 in the form of tubes as shown in FIGS. 10 and 11, which, like the side supports 55,56, are preferably made of a non-magnetic material. These spacers 57 substantially absorb the compressive forces acting on the coil assembly 50 between the side supports 55,56 in the region of the apertures 52.

[0061] A circumferential ring of a potting compound 60 such as a casting resin, for example epoxy or polyester, connects the side supports 55,56 and thereby holds the coil assembly 50 together.

[0062] Not shown in the drawing are the lead wires of the coil 53, which may be routed through the potting compound 60 or through the side supports 55,56.

[0063] Since the operating voltage of the actuator 14 is below the contact voltage, the coil arrangements 32 to 35 can be directly wet cooled.

[0064] A section through an alternative coil arrangement 63 is explained with reference to FIG. 12.

[0065] Embedded in a potting compound 64, seven coils 64 with cores 65 are arranged around two armatures 66 in this design example. The number of armatures 66 and coils 65 can easily be increased, as in the previous design example. As shown in FIG. 12, only one coil 65 can be arranged between the armatures 66, which is thus used twice.

[0066] In this design example, the armatures 67 have stacks of sheets of square cross-section on a shaft 69, which are braced by spacer sleeves 70 as in the previous design example. So that coil arrangements 63 can also be braced on mounting rods 71 in a comparable manner, but the potting compound 64 would generally not withstand the pressure, tube sections 72 are introduced into the potting compound 64 to absorb these compressive forces.

[0067] The two armatures 67 exemplified here are molded with the coils 65 in a housing 73 of a non-magnetic material.

[0068] The explained design example of a linear actuator can be extended almost arbitrarily. Thus, further armatures and coil arrangements can be arranged in parallel. It is also possible to increase the number of stack of sheets on the shaft of an armature and, consequently, the number of coil arrangements. In both cases, there is an increase in the performance of the actuator.

[0069] Another alternative is a linear motor in which an armature is moved by a plurality of coil arrangements which are then preferably arranged directly in series.

[0070] A Rotary Actuator

[0071] The winding of the coils with flat, self-insulating foils coated with a conductor, preferably copper, alternatively e.g., aluminum, possibly also two-layer windings, a conductive and an insulating foil, has several advantages. Due to the large conductor cross-section, high currents of regularly more than 10 A can flow without any problems. In addition, the geometry of a coil can be changed by sawing, cutting, and drilling perpendicular to the films extending over the surface.

[0072] For example, FIG. 13 shows a top view of an outer winding of a coil assembly 80 of conical design. As the sectional view shown in FIG. 14 indicates, the coil assembly 80 has a coil 81 on a core 82, or possibly on a simple winding body.

[0073] Such coil arrangements 80 are simple in terms of manufacturing. The winding is applied to a long core, in FIG. 15 perpendicular to the drawing plane. The coil geometry shown in FIG. 13 can then be obtained from such a blank using a laser or by simple sawing. If necessary, the open coil edges must still be reworked so that there is no winding closure.

[0074] The conical geometry of the coil assembly 80 readily permits an annular arrangement. FIG. 16. The twenty-four coil arrangements 83,84 arranged in a circular ring form the disk-shaped stator 85 of a rotary actuator. Radially inboard, the coil assemblies 83,84 are captured with alternating radial spacing in a mounting and positioning ring 86 that includes a central aperture 100. A further mounting and positioning ring 87 lying radially outward is provided.

[0075] Both mounting and positioning rings 86,87 can be created in a simple manner by potting the coil assemblies 83,84 with a synthetic resin or the like. Particularly in the case of potting, it is easily possible to skin the two flat sides of the coil assemblies 83,84 as a sliding surface for an oil film during operation. Other techniques for applying a skin of a material thickness of approx. 0.2 to 0.3 mm thickness can nevertheless be used. In addition, a comparatively thin layer of the potting compound can be used to bond the coil assemblies 83,84 to one another.

[0076] In particular, if the outer mounting and positioning ring 87 is made of a cast resin, openings 88 are formed by spacers 89 in the form of tubes to provide pressure stability.

[0077] The geometry of the rotor 90 reproduced in detail in FIG. 17 as the core of the rotary actuator, a laminated core consisting of a plurality of transformer laminations as in the case of the armature 1, is basically known. In the embodiment, see FIG. 18, six blades 94 extend radially outward at a central ring 91, the central breakthrough 92 of which is dispersed by a rotor shaft 93—see FIG. 18. The radial extension of the blades 94 of the rotor 90, which is arranged between stators 85, cf. FIG. 18, extends approximately to the dashed circle segment 95 in FIG. 16, and the radial extension of the ring 91 extends to the dashed circle segment 101. Thus, the radially inner mounting and positioning ring 86 is covered by the ring 91 and the blades 94 are securely positioned between the coil assemblies 80, cf. FIG. 9.

[0078] The rotary actuator shown in sections in FIG. 18 has three laminated rotors 90 on the rotor shaft 93, connected in series as it were. Comparable to the preceding design examples, the rotors 90 are evenly spaced by spacer sleeves 96 and two coil assemblies 80 enclose one rotor 90. Further modules consisting of a rotor 90 and a coil arrangement 90 can be connected in modular fashion. At the ends of the rotor shaft 93, the outer spacer sleeves are then fixed to the rotor shaft 93, for example as explained for the armature 1. Accordingly, the central aperture 100 of the radially inner mounting and positioning ring 86 is to be dimensioned for the passage of the rotor shaft 93 and the spacer sleeve 96.

[0079] An oil film may still be provided in the space between a coil arrangement 80 and a rotor 90, if necessary.

[0080] The coil arrangements 80 with the radially outer mounting and positioning ring 87 are also spaced apart by spacer sleeves 97 on mounting rods 98 and braced relative to an indicated housing 99.