Brake device

Abstract

Braking device (100), in particular eddy current braking device, comprising at least a stator part (10), a rotor part (50) rotatably arranged relative to the stator part (10) about an axis of rotation (12), with a shaft (52) arranged in the axis of rotation (12), wherein the rotor part (50) and the stator part (10) are arranged concentrically to each other with an air gap (14) between them, wherein the stator part (10) comprises an induction device (20) configured for inducing eddy currents by a magnetic field, wherein the rotor part (50) comprises an excitation device (60) configured for generating a primary magnetic field (54) directed in the radial direction (16), wherein the induction device (20) is configured to generate a primary magnetic field (54) directed in the radial direction (16) at least partially opposite to the primary magnetic field (54) as a result of a rotation of the rotor part (50) about the axis of rotation (12). directed secondary magnetic field (56) is formed,wherein the induction device (20) comprises a substantially ring-shaped base body (22) with a plurality of pole elements (24) directed radially to the rotor part (50) and an electrically conductive element (30) which at least partially encloses the pole elements (24).

Description

State of the art

[0001] The invention relates to a braking device, in particular an eddy current braking device.

[0002] A braking device is installed in a vehicle, such as a motor vehicle, truck, or rail vehicle, and serves to reduce or limit the vehicle's speed. If the braking device is installed in a machine, it serves to reduce or limit the speed of moving machine parts.

[0003] Braking devices are divided according to their mode of operation into mechanical brakes, which are based on dissipating movement through friction between a fixed body and the moving body, typically a disc, electric brakes, and magnetic brakes. Typical electric braking devices are electrodynamic braking devices, in particular eddy current brakes, electromotive brakes, and resistance brakes. With an electromotive brake, a drive motor acts as a generator during braking and is typically fed back into the vehicle's power supply. With an eddy current braking device, the eddy current effect is used, in which an electrically conductive material, typically a metal disc, is moved through a magnetic field, thereby inducing eddy currents in the material. These eddy currents, in turn, generate a magnetic field that counteracts the generated torque and thereby slows down the disc.The strength of the braking effect depends on several parameters, for example the conductivity of the brake disc, whereby the induced currents are directly proportional to the electrical conductivity of the material used.

[0004] A copper disc is therefore slowed down more effectively than a steel disc of the same construction. The strength of the braking effect also depends on the direction of the magnetic field, with the greatest braking effect being achieved when the magnetic field passes perpendicularly through the moving disc; on the air gap, whereby the larger the air gap, the smaller the maximum braking effect; on the shape of the disc, with discs with a circumferential comb-shaped structure or cracks having a reduced braking effect because the annular eddy currents can no longer develop over a large area; on the area under the excitation pole, whereby the smaller the area under the pole, the lower the braking effect; on the speed, with the braking effect strongly dependent on the relative speed between the field and the disc; and on the coil current, whereby the higher the current flowing through the magnet, the stronger the magnetic field and thus the braking force.

[0005] DE 102016108646 B4 describes an electrodynamic brake that uses an induction device characterized by both high permeability and high electrical conductivity. Due to the design of the induction device, these two properties are spatially separated from one another. The induction device comprises a structure made of several perforated plates extending at least substantially parallel to one another with aligned holes through which pins, in particular made of metal, extend. Disclosure of the invention

[0006] The object of the invention is to provide an improved braking device.

[0007] A further object of the invention is to provide a use for the improved braking device.

[0008] Another object of the invention is to provide a vehicle with an improved braking device.

[0009] The objects are achieved by the features of the independent claims. Advantageous embodiments and advantages of the invention emerge from the further claims, the description, and the drawings.

[0010] A braking device is proposed, in particular an eddy current braking device, which comprises at least one stator part, a rotor part arranged so as to be rotatable relative to the stator part about an axis of rotation, with a shaft arranged in the axis of rotation, wherein the rotor part and the stator part are arranged concentrically to one another with an air gap between them, wherein the stator part comprises an induction device which is designed to induce eddy currents by means of a magnetic field, wherein the rotor part comprises an excitation device which is designed to generate a primary magnetic field directed in the radial direction, wherein the induction device is designed to generate a secondary magnetic field which is directed at least partially opposite to the primary magnetic field in the radial direction as a result of a rotation of the rotor part about the axis of rotation.

[0011] The rotor section can be advantageously implemented as an internal rotor within the stator section, allowing for a smaller design. The radial flux guidance allows for increased power density.

[0012] In the case of an external rotor, the stator-rotor arrangement can be reversed, with the stator section located inside the rotor. Accordingly, all arrangements, geometries, and orientations, such as pole elements directed radially outward, are also possible in reverse.

[0013] Radial flux guidance avoids typical problems of axial-flux machines, where the maximum speed is limited by the yield point or tensile strength of the material due to the large rotor diameter, high rotor mass, and typical disk shape. Likewise, the large rotor diameter of axial-flux machines causes axial deformation at high speeds, resulting in a significant change in the air gap. In the worst case, this increases the air gap. As a result, the power density at high speeds is reduced.

[0014] The magnetic properties are also altered, and the braking device behaves differently than the (design) simulation model underlying the device. The predictive power of the model is limited. Axial flux machines also require greater manufacturing effort for the electrical lamination stacks, as a single lamination stack consists of several different sized laminations. Furthermore, the rotors are manufactured from solid material, requiring a correspondingly high level of machining effort.

[0015] According to a favorable embodiment of the braking device, the induction device can comprise a substantially annular base body with a plurality of pole elements directed radially toward the rotor part and an electrically conductive element that at least partially encloses the pole elements. This advantageously allows the realization of an eddy current brake with radial magnetic flux guidance.

[0016] According to a favorable design of the braking device, the base body can comprise an electrical lamination stack with electrical laminations stacked in the axial direction, or it can be designed as an electrical lamination stack with electrical laminations stacked in the axial direction. Electrical laminations are relatively easy to manufacture. This can advantageously reduce the disruptive skin effect.

[0017] According to a favorable embodiment of the braking device, the electrically conductive element can comprise individual electrically conductive sheets that enclose the pole elements and are arranged substantially concentrically to one another in the radial direction. The radial spacing between the individual electrical sheets allows for favorable flow of coolant in the axial direction.

[0018] In a favorable design of the braking device, the electrically conductive individual sheets can be ring-shaped. This allows for a simple construction. The radial spacing between the individual electrical sheets allows for favorable flow of coolant in the axial direction.

[0019] According to a further advantageous embodiment of the braking device, the electrically conductive individual sheets can be designed as sheet metal strips, wherein adjacent sheet metal strips, in particular at end faces, are electrically conductively connected to one another, in particular soldered or welded.

[0020] According to a favorable embodiment of the braking device, the electrically conductive element can comprise at least one electrically conductive sheet metal strip having a plurality of through-openings for the plurality of pole elements. The electrically conductive sheet metal strip is applied to the plurality of pole elements in a spiral shape around the rotational axis with several turns. The radial spacing between the individual electrical sheets allows for favorable flow of a coolant in the axial direction.

[0021] Advantageously, a plurality of lamination layers can be arranged radially one above the other. The radial spacing between the individual laminations allows for favorable flow of coolant in the axial direction. This allows for good heat transfer, thus advantageously reducing thermal stress during operation of the braking device.

[0022] A suitable offset of the electrical sheet stack can be achieved. This can reduce cogging torque.

[0023] According to a favorable embodiment of the braking device, the electrically conductive element can comprise an electrically conductive foam which encloses the plurality of pole elements.

[0024] For the purposes of the present invention, an electrically conductive foam is understood to be a porous structure permeated by a multitude of pores. Pores form hollow bodies and / or cavities within the structure, which are separated from one another by webs, particularly solid webs. The porous structure is, in particular, a two-phase system formed from a solid and a gaseous phase and / or a solid and a liquid phase.

[0025] The metallic electrically conductive material of the porous structure has in particular an electrical conductivity of at least 20·10 6 S / m (relative to room temperature) and is, for example, a metal.

[0026] The porous structure can be manufactured in just a few steps. Properties of the porous structure, such as the size of the pores or the width of the webs, can be easily adapted to the requirements of a specific application. Furthermore, assembly steps can be reduced. For example, after the stator laminated core is completed, it can be directly foam-coated with metal foam without the need for prefabrication of the metal foam.

[0027] The porous structure exhibits particularly good mechanical properties, such as high specific strength and high specific stiffness. This allows for a smaller and lighter design of the braking device according to the invention.

[0028] Advantageously, the porous structure may be an aluminum foam or a copper foam or a magnesium foam or comprises an aluminum foam or a copper foam or a magnesium foam.

[0029] Advantageously, the porous structure can be open-pored. Open-pored means that the pores and / or cavities of the porous structure communicate with each other and with the environment. In particular, a void volume of the porous structure is formed by the sum of the pores and / or cavities that communicate with each other and with the environment.

[0030] According to a favorable design of the braking device, the axial side surfaces of the pole elements can be inclined at a helical angle counter to the axial direction. This can reduce cogging torque.

[0031] According to a favorable embodiment of the braking device, the excitation device can comprise a base excitation body enclosing the shaft and having a plurality of excitation pole elements directed radially toward the stator part, in particular each of which comprises an electrical excitation coil. In this way, the eddy-current brake can advantageously be implemented in the form of an asynchronous machine with 100% slip and constant current supply.

[0032] According to a favorable design of the braking device, the exciter base body can comprise a second electrical sheet stack with individual sheets stacked in the axial direction or be designed as a second electrical sheet stack with individual sheets stacked in the axial direction. In this way, the eddy current brake can advantageously be implemented as an asynchronous machine with 100% slip and constant current supply.

[0033] According to a favorable design of the braking device, the electrical excitation coils can be designed for electrical coupling to an electrical control unit. This allows the braking effect of the eddy-current brake to be suitably controlled and / or regulated.

[0034] According to a favorable design of the braking device, the number of pole elements directed radially toward the rotor part and the number of excitation pole elements directed radially toward the stator part can differ by no more than 50%. This allows a particularly favorable braking effect to be achieved.

[0035] According to a favorable embodiment of the braking device, the electrically conductive element can have one or more coolant paths through which a coolant flows.

[0036] This allows for axial flow of coolant. This provides the advantage of optimal heat transfer. This minimizes thermal stress on the braking system. This has the advantage of improving braking system safety.

[0037] According to a favorable embodiment of the braking device, one or more slip-ringless rotary transformers can be used to transmit an excitation current to the excitation device arranged on the rotor part.

[0038] The advantage of the eddy-current braking device with radial flux is its increased power density. This allows for optimized installation space for the braking device.

[0039] According to a further aspect, a use of a braking device comprising an eddy current braking device is proposed, wherein the braking device can be installed in a road vehicle, in particular a motor vehicle or lorry or a rail vehicle.

[0040] According to a further aspect, a vehicle is proposed that includes a braking device, in particular an eddy current braking device. The vehicle can be a road vehicle or a rail vehicle. The braking device with radial flux guidance advantageously enables improved power density of the braking device. This allows for optimized installation space and axial coolant flow.

[0041] According to a further aspect, a vehicle test bench is proposed that includes a braking device, in particular an eddy current braking device. This enables a test bench with high power density, which preferably exclusively provides a braking torque. The braking device with radial flux guidance advantageously enables improved power density of the braking device. This allows for optimized installation space and axial coolant flow. drawing

[0042] Further advantages will become apparent from the following description of the drawings. The figures illustrate exemplary embodiments of the invention. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0043] Examples include: Fig. 1 is an isometric view of a braking device with radial flux guidance according to an embodiment of the invention; Fig. 2 a plan view of a cross section through the braking device according to Fig. 1 in plan view with indicated section planes III-III and IV-IV; Fig. 3 a longitudinal section through the braking device along the section plane III-III Fig. 2; Fig. 4 a longitudinal section through the braking device along the section plane IV-IV Fig. 2; Fig. 5 a plan view of a braking device with spiral wound sheet metal strips according to a further embodiment; Fig. 6 a plan view of a braking device with sheet metal rings in the axial direction in a double-T shape according to a further embodiment; Fig. 7 is a plan view of a braking device with a porous material according to another embodiment; Fig. 8 a longitudinal section through one side of the braking device Fig. 7; Fig. 9 a longitudinal section through one side of a braking device with axial coolant flow according to a further embodiment; Fig. 10 is an isometric view of a braking device with a set electrical sheet according to a further embodiment; Fig. 11 a schematic representation of a radially directed magnetic field of the braking device; Fig. 12 a schematic representation of a segment of the braking device with a radially directed magnetic field; Fig. 13 a plan view of pole elements of the braking device with sheet metal rings with axial coolant flow; Fig. 14 a plan view of pole elements of the braking device with sheet metal rings in double-T shape with axial coolant flow; Fig. 15 a plan view of an unwound sheet metal strip; and Fig. 16 an enlargement of the plan view of the unwound sheet metal strip from Fig. 15.

[0044] Before describing the invention in detail, it should be noted that it is not limited to the specific components of the device, as these components may vary. The terms used herein are intended solely to describe particular embodiments and are not intended to be limiting. Furthermore, when the singular or indefinite articles are used in the description or claims, this also refers to the plural of these elements, unless the overall context clearly indicates otherwise.

[0045] The directional terminology used below, including terms such as "left," "right," "top," "bottom," "before," "behind," "after," and the like, is intended solely to enhance understanding of the figures and is in no way intended to limit the scope of the invention. The components and elements depicted, as well as their design and use, may vary according to the considerations of a person skilled in the art and may be adapted to specific applications. Embodiments of the invention

[0046] In the figures, components of the same type or function similarly are designated by the same reference numerals. The figures are merely examples and are not to be construed as limiting.

[0047] The Fig. 1 to 4 show a first embodiment of the invention. Fig. 1 shows an isometric view of a braking device 100 with radial flux guidance. Fig. 2 shows a plan view of a cross section through the braking device according to Fig. 1 in plan view with indicated section planes III-III and IV-IV. Fig. 3 shows a longitudinal section through the braking device 100 along the section plane III-III of Fig. 2. Fig. 4 shows a longitudinal section through the braking device 100 along the section plane IV-IV of Fig. 2.

[0048] In the exemplary embodiments, the braking device 100 is depicted as an internal rotor, in which the rotor part is arranged radially inside the stator part. If the braking device 100 is designed as an external rotor, the stator-rotor arrangement can be reversed, with the stator part arranged inside the rotor part. Accordingly, all arrangements, geometries, and orientations are also possible in reverse, e.g., with pole elements directed radially outward.

[0049] Fig. 1 shows a schematic isometric representation of a braking device 100 in the form of an eddy current braking device with radial flux guidance. The braking device 100 has a stator part 10 arranged concentrically around a central axis 12, which is designed as the axis of rotation 12. The stator part 10 is part of an induction device 20, which has an electrically conductive element 30. The stator part 10 further has an electrical sheet stack 26 and forms an electrically conductive element 30 of the induction device 20. A shaft 52 is arranged on the axis of rotation 12 and is radially surrounded by a rotor part 50. An excitation device 60 has at least one excitation pole element 64 and a second electrical sheet stack 68. Preferably, a plurality of excitation pole elements 64 and a plurality of second electrical sheet stacks 68 are provided. An excitation coil 66 is arranged concentrically and radially around the shaft 52.The number of excitation pole elements 64 of the rotor part 50 and the stator part 10 shown is for visualization purposes only and may vary depending on the design of the braking device and its optimization. The shape of the stator part 10 may also vary. The shape of the rotor part 50 may also vary. The electrically conductive element 30 may, for example, consist of several axially extending individual laminations 32. The individual laminations 32 are made of, for example, aluminum or copper or comprise aluminum or copper.

[0050] As from Fig. As can be seen in Figure 2, the stator part 10 is arranged concentrically in the radial direction 16 around the shaft 52. The induction device 20 is divided into eighteen subunits. An air gap 14 is arranged between the stator part 10 and the rotor part 50. The rotor part 50 has an exciter base body 62 and the exciter pole elements 64, each of which is arranged concentrically and radially around the shaft 52.

[0051] The sectional view of the Fig. 3 shows the view along the section line III-III from Fig. 2, which is positioned radially relative to the rotational axis 12 at the position of the stator part 10 and the rotor part 50. The rotational axis 12 is shown in the center of the braking device 100. The induction device 20 with the pole element 24 has the electrical sheet stacks 26 and the conductive elements 30 arranged on either side of them. Viewed radially inward, the excitation device 60 is shown with the excitation base body 62 and the second electrical sheet stack 68. The air gap 14 is arranged between the stator part 10 and the rotor part 60.

[0052] The sectional view of the Fig. 4 shows the view along section line IV-IV from Fig. 2 at a position rotated relative to the section line III-III, where the excitation coils can be seen. The induction device 20 with the electrically conductive elements 30 is visible. The excitation coils 66 are each arranged around the excitation base body 62. The air gap 14 is shown between the excitation pole element 64 and the induction device 20.

[0053] Fig. 5 shows a plan view, perpendicular to the shaft 52 arranged on the rotational axis 12, of the braking device 100 designed as an eddy current braking device with spirally wound sheet metal strips as the electrically conductive element 30 according to a further exemplary embodiment. Sheet metal layers 42 and electrically conductive sheet metal strips 38 are arranged internally in the stator part 10 between the base body 22 and the excitation coils 66. The pole elements 24 are arranged in the viewing plane behind the sheet metal layers 42. The excitation pole elements 64 are arranged between the excitation coils and the sheet metal layers 42. The air gap 14 can be seen between the pole elements 24 and the excitation pole elements 64. An excitation base body 62, which is part of the excitation device 60, is arranged concentrically around the shaft 52.In the illustrated embodiment, the electrically conductive element 30 is designed as a spiral or as individual inserted double-T sheets or ring sheets with subsequent soldering.

[0054] Fig. 6 shows a plan view in a further sectional plane of the braking device 100 designed as an eddy current braking device with sheet metal rings in the axial direction in a double-T shape as the electrically conductive element 30 according to a further exemplary embodiment. The stator part 10 with the base body, the pole elements 24, and the electrical sheet stack 26 of the induction device 20 are arranged concentrically and in the radial direction 16 around the shaft 52. The electrical sheet stack 26 has the electrical sheets 28 with the sheet strips 34, each of which has an individual sheet 32. The rotor part 50 has the excitation pole elements 64, the excitation coils 66, each with the second electrical sheet stack 68, and the excitation base body 62. The air gap 14 is arranged between the stator part 10 and the rotor part 50. In the embodiment shown, the electrically conductive element 30 is constructed from individual inserted double-T sheets or ring sheets with subsequent soldering.

[0055] Fig. Figure 7 shows a top view of a braking device 100 with a porous material 44 as an electrically conductive element according to another embodiment, comprising the stator part 10 and the rotor part 50. The electrically conductive element 30 of the induction device 20 comprises an electrically conductive foam 44 arranged internally to the base body 22. The rotor part 50, which rotates during operation, comprises the excitation device 60 with the excitation coils 66, the excitation base body 62, and the excitation pole elements 64.

[0056] Fig. Figure 8 shows a longitudinal section through one side of the braking device 100 of Fig. 7. The pole element 24 of the induction device 20 of the stator part 10 is arranged radially outward. The air gap 16 separates the stator part 10 from the rotor part 50 with the excitation device 60, which includes the excitation base body 62 with the second electrical sheet stack 68, and the excitation coil 66. The rotor part 50 is connected to the shaft 52.

[0057] Fig. Figure 9 shows a longitudinal section through one side of a braking device 100, designed as an eddy current brake, with axial coolant flow according to another embodiment. A coolant 70 can pass between the spaced-apart individual plates 32.

[0058] The direction of the coolant 70 is indicated by an arrow. The second electrical sheet stack 68 is arranged around the exciter base body 62 and forms the excitation coil 66. The flow of the coolant 70 runs axially through the electrically conductive elements 30. The example shown in the figure corresponds to the double-T variant. However, the flow direction of the coolant 70 is essentially the same for the other possible variants described. The axial flow ensures the best possible heat transfer.

[0059] Fig. Figure 10 shows an isometric view of a stator part 10 of the braking device 100 designed as an eddy current braking device. The stator part 10 comprises the induction device 20 with the electrically conductive element 30 and the electrical sheet stack 26. The pole elements 24 each have a side surface 46 on both sides. An oblique angle 48 is formed.

[0060] The electrical lamination stack 26 in the stator 10 is designed with a twist, as is common in conventional electrical engineering. This allows the cogging torque to be reduced.

[0061] Fig. Figure 11 shows a schematic sectional view of one side of a stator part 10 with the induction device 20, which has the electrical sheet stack 26. The rotor part 50 with the excitation device 60, which has the excitation coil 68, is arranged at a distance from the stator part 10. The shaft 52 is arranged on the rotational axis 12. The shaft 52 is connected to the rotor part 50. A control unit 80 is connected to the excitation coil 66 and regulates and controls a primary magnetic field 54 to be generated, the field lines 55 of which penetrate the stator part 10.

[0062] Fig. 12 shows a schematic representation of a segment-like section of the braking device 100 designed as an eddy current braking device from Fig. 11 in a sectional view in a plane spanned perpendicular to the rotational axis 12. The stator part 10 has the pole elements 24, between which the field lines 54 of the primary magnetic field 54 run. The primary magnetic field 54 extends both in the area of ​​the stator part 10 and the rotor part 50. An excitation current 72 shows the current flow in the excitation coils 66 and the pole elements 24.

[0063] Shaft 52 is drawn on the rotational axis at the tip of the segment and runs perpendicular to the drawing surface. The secondary magnetic field 56 runs in the stator part 10. The magnetic flux B of the primary magnetic field 54 is generated by the electrical excitation. As a result of the rotational movement of the rotor part 50, an eddy current is generated, which can generate the second magnetic field 56. This second magnetic field 56 opposes the primary magnetic field 54 and provides a braking torque.

[0064] Fig. Figure 13 shows a plan view in the radial direction of a section of a braking device 100 designed as an eddy current braking device with sheet metal rings as the electrically conductive element 30 with axial coolant flow. Along the radial direction 16, the coolant streams 70 run along the individual sheets 32 and enclose the pole elements 24. The electrically conductive element 30 is ring-shaped in this embodiment.

[0065] Fig. 14 shows, in a plan view of pole elements 24 in the radial direction, a section of a braking device 100 designed as an eddy current brake with sheet metal rings in a double-T shape with axial coolant flow. The flow of the coolant 70 is shown as a directional arrow 70, which runs counter to the radial direction. An end face 36 of the sheet metal strips 34 is in contact with an electrically conductive connection 35, in particular designed as an electrically conductive connection 35. The sheet metal strips 34 can, for example, be soldered to form an electrically conductive connection 35. The electrically conductive element 30 is designed in the double-T shape in this embodiment.

[0066] Fig. 15 and Fig. 16 show a schematic representation of the sheet metal strip 38, where Fig. 16 shows an enlargement of the sheet metal strip 48. Through-openings 40 are formed in the sheet metal strip 38. The through-openings 40 are spaced apart by a distance 41.

[0067] The distance 41 is calculated from a first side 43 of the through-opening 40 to the first side 43 of the next, adjacent through-opening 41.

[0068] As particularly in Fig. 15, the distances 41 between the lead-through openings 40 change along the extent of the sheet metal strip 38 in order to Fig. 5 to enable the spiral arrangement of the sheet metal strip 38 on the pole elements 24 of the stator part 10.

[0069] Since in the Fig.1 to 16 only show partial sections of the braking device 100, the braking device 100 as a complete unit and its functional relationships are described below. The braking device 100 comprises at least one stator part 10, a rotor part 50 arranged so as to be rotatable relative to the stator part 10 about the axis of rotation 12, with the shaft 52 arranged in the axis of rotation 12. The rotor part 50 is arranged radially inside the stator part 10 with an air gap 14 spaced therefrom, wherein the stator part 10 comprises the induction device 20, which is designed to induce eddy currents through a magnetic field. The rotor part 50 comprises the excitation device 60, which is designed to generate the primary magnetic field 54 directed in the radial direction 16.The induction device 20 is designed to generate the secondary magnetic field 56 which is directed at least partially opposite to the primary magnetic field 54 in the radial direction 16 as a result of a rotation of the rotor part 50 about the axis of rotation 12.

[0070] The induction device 20 comprises the substantially annular base body 22 with a plurality of radially inwardly directed pole elements 24 and the electrically conductive element 30, which at least partially encloses the pole elements 24.

[0071] The base body 22 comprises the electrical sheet stack 26 with electrical sheets 28 stacked in the axial direction 12 or is designed as an electrical sheet stack 26 with electrical sheets 28 stacked in the axial direction 12.

[0072] The electrically conductive element 30 can comprise electrically conductive individual sheets 32 that surround the pole elements 24 and are arranged substantially concentrically with one another in the radial direction 16. The electrically conductive individual sheets 32 can be annular. The electrically conductive individual sheets 32 can be formed as sheet metal strips 34, wherein adjacent sheet metal strips 34 are electrically conductively connected to one another, in particular soldered or welded, particularly at end faces 36.

[0073] The electrically conductive element 30 can comprise at least one electrically conductive sheet metal strip 38, which has a plurality of through-openings 40 for the plurality of pole elements 24, wherein the electrically conductive sheet metal strip 38 is applied to the plurality of pole elements 24 in a spiral manner around the rotational axis 12 with several turns. Thus, a plurality of sheet metal layers 42 are advantageously arranged one above the other in the radial direction 16.

[0074] The electrically conductive element 30 may comprise an electrically conductive metallic foam 44 which encloses the plurality of pole elements 24.

[0075] The axial side surfaces 46 of the pole elements 24 can extend at a helix angle 48 relative to the axial direction 12. The excitation device 60 can comprise an excitation base body 62 enclosing the shaft 52 and having a plurality of radially outwardly directed excitation pole elements 64, in particular each of which excitation pole element 64 comprises an electrical excitation coil 66. The excitation base body 62 can comprise a second electrical sheet stack 68 with individual sheets stacked in the axial direction 12 or can be designed as a second electrical sheet stack 68 with individual sheets stacked in the axial direction 12.

[0076] The electrical excitation coils 66 can be configured for electrical coupling to an electrical control unit 80. The number of radially inwardly directed pole elements 24 and the number of radially outwardly directed excitation pole elements 64 can differ by a maximum of 50%.

[0077] The electrically conductive element 30 may have one or more coolant paths provided for the flow of the coolant 70.

[0078] The eddy current braking device may comprise one or more slip-ringless rotary transformers for transmitting an excitation current to the excitation device 60 arranged on the rotor part 50.

[0079] The braking device 100 can conveniently be installed in a vehicle, wherein the vehicle can be a motor vehicle or a rail vehicle. Reference symbol 10 Stator part 12 axis of rotation, central axis 14 Air gap 16 radial direction 20 Induction device 22 basic bodies 24 pole element 26 Electrical sheet package 28 Electrical sheet 30 electrically conductive element 32 single sheets 34 metal strips 35 electrically conductive connection 36 front side 38 electrically conductive sheet metal strips 40 Feed-through opening 41 distance 42 sheet layers 44 electrically conductive foam 46 side surface 48 helix angles 50 rotor part 52 Wave 54 primary magnetic field 55 field lines 56 secondary magnetic field 60 Excitation device 62 pathogen base bodies 64 Excitation pole element 66 Excitation coil 68 second electrical sheet package 70 coolant 72 Excitation current 74 Eddy current 80 control unit 100 braking device QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102016108646 B4

[0005]

Claims

[1] Braking device (100), in particular eddy current braking device, comprising at least a stator part (10), a rotor part (50) arranged to rotate relative to the stator part (10) about a rotational axis (12), with a shaft (52) arranged in the rotational axis (12), wherein the rotor part (50) and the stator part (10) are arranged concentrically to each other with an air gap (14) spaced from each other, wherein the stator part (10) comprises an induction device (20) which is designed to induce eddy currents through a magnetic field, wherein the rotor part (50) comprises an excitation device (60) which is designed to generate a primary magnetic field (54) directed in the radial direction (16), wherein the induction device (20) is designed to generate a secondary magnetic field (56) which is directed at least partially opposite to the primary magnetic field (54) in the radial direction (16) as a result of a rotation of the rotor part (50) about the axis of rotation (12). [2] Braking device according to claim 1, wherein the induction device (20) comprises a substantially annular base body (22) with a plurality of pole elements (24) directed radially towards the rotor part (50) and an electrically conductive element (30) which at least partially encloses the pole elements (24). [3] Braking device according to claim 2, wherein the base body (22) comprises an electrical sheet stack (26) with electrical sheets (28) stacked in the axial direction (12) or is designed as an electrical sheet stack (26) with electrical sheets (28) stacked in the axial direction (12). [4] Braking device according to claim 2 or 3, wherein the electrically conductive element (30) comprises electrically conductive individual sheets (32) which enclose the pole elements (24) and are arranged substantially concentrically to one another in the radial direction (16). [5] Braking device according to claim 4, wherein the electrically conductive individual sheets (32) are annular. [6] Braking device according to claim 4, wherein the electrically conductive individual sheets (32) are designed as sheet metal strips (34), wherein adjacent sheet metal strips (34), in particular at end faces (36), are electrically conductively connected to one another, in particular soldered or welded. [7] Braking device according to claim 2 or 3, wherein the electrically conductive element (30) comprises at least one electrically conductive sheet metal strip (38) which has a plurality of through openings (40) for the plurality of pole elements (24), wherein the electrically conductive sheet metal strip (38) is applied to the plurality of pole elements (24) in a spiral manner around the axis of rotation (12) with a plurality of turns. [8] Braking device according to claim 2 or 3, wherein the electrically conductive element (30) comprises an electrically conductive foam (44) which encloses the plurality of pole elements (24). [9] Braking device according to one of claims 2 to 8, wherein axial side surfaces (46) of the pole elements (24) extend with a helix angle (48) against the axial direction (12). [10] Braking device according to one of the preceding claims, wherein the excitation device (60) comprises an excitation base body (62) enclosing the shaft (52) with a plurality of excitation pole elements (64) directed radially towards the stator part (10), in particular of which each excitation pole element (64) comprises an electrical excitation coil (66). [11] Braking device according to claim 10, wherein the exciter base body (62) comprises a second electrical sheet stack (68) with individual sheets stacked in the axial direction (12) or is designed as a second electrical sheet stack (68) with individual sheets stacked in the axial direction (12). [12] Braking device according to claim 10 or 11, wherein the electrical excitation coils (66) are designed for electrical coupling to an electrical control unit (80). [13] Braking device according to one of claims 2 to 12, wherein a number of pole elements (24) directed radially towards the rotor part (50) and a number of excitation pole elements (64) directed radially towards the stator part (10) differ by at most 50%. [14] Braking device according to one of the preceding claims, wherein the electrically conductive element (30) has one or more coolant paths provided for the flow of a coolant (70). [15] Braking device according to one of the preceding claims, comprising one or more slip-ring-less rotary transformers for transmitting an excitation current to the excitation device (60) arranged on the rotor part (50). [16] Use of a braking device (100) according to one of claims 1 to 15, in particular an eddy current braking device in a road vehicle, in particular a motor vehicle or lorry, or a rail vehicle. [17] Vehicle with a braking device (100) according to one of claims 1 to 15. [18] Vehicle test bench with a braking device (100) according to one of claims 1 to 15 for providing a braking torque.

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