Braking device, and method for generating a total braking torque

Abstract

The invention relates to a braking device (200), to a vehicle (42) having a braking device, and to a method for generating a total braking torque, comprising an eddy current braking device (10), an energy storage device (24), and an electric machine (46, 48), which is connected to the energy storage device (24). The eddy current braking device (10) has a stator part (12), a rotor part (16) with a shaft (18), and an actuator device (10, 28, 32). The stator part (12) comprises an exciter device (22) for generating a primary magnetic field, and an induction device induces eddy currents, whereby a first braking torque (120,122) can be generated. The actuator device (10, 28, 32) generates a force (30, 34) by means of which the rotor part (16) and the stator part (12) are displaced relative to each other, and a second braking torque (120,122) is generated by the stator part (12) and the rotor part (16) contacting each other. The eddy current braking device (10) and / or the electric machine (46, 48) are temporarily coupled to at least one wheel (44) of the vehicle (42).

Description

[0001] Description

[0002] Braking device and method for generating a total braking torque

[0003] The invention relates to a braking device with an eddy current braking device, an energy storage device and at least one electric machine, as well as a method for generating a total braking torque.

[0004] State of the art

[0005] A braking device is installed in a vehicle, such as a car, 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.

[0006] Braking devices are classified according to their function into mechanical brakes, which rely on friction between a stationary and a moving body, typically a disc, electric brakes, and magnetic brakes. Typical electric braking devices include electrodynamic brakes, particularly eddy current brakes, electromechanical brakes, and resistance brakes. In an electromechanical brake, a drive motor is used as a generator during braking, and energy is typically fed back into the vehicle's electrical system. Eddy current brakes utilize the eddy current effect, in which an electrically conductive material, typically a metal disc, is moved through a magnetic field. This induces eddy currents in the material, which in turn generate a magnetic field that opposes the torque generated, thus braking the disc.The strength of the braking effect depends on several parameters, such as the conductivity of the brake disc, with the induced currents being directly proportional to the electrical conductivity of the material used.

[0007] DLR-4348WO

[0008] 2025-12-17 Furthermore, the strength of the braking effect depends on the direction of the magnetic field, with the greatest braking effect being achieved when the magnetic field passes perpendicularly through the moving disk; on the air gap, whereby the larger the air gap, the smaller the maximum braking effect; on the shape of the disk, whereby disks with a circumferentially comb-like structure or cracks exhibit a reduced braking effect, since the ring-shaped eddy currents can no longer form 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, whereby the braking effect is strongly dependent on the relative speed between field and disk; and on the coil current, whereby the higher the current flowing through the magnet, the stronger the magnetic field and thus the braking force.

[0009] German patent DE 102016108646 B4 describes an electrodynamic brake in which an induction device is used that is characterized by both high permeability and high electrical conductivity. Due to the design of the induction device, these two properties are spatially separated. The induction device comprises a structure of several perforated metal sheets extending at least substantially parallel to one another, with aligned holes through which pins, in particular made of metal, extend.

[0010] Disclosure of the invention

[0011] The object of the invention is to provide an improved braking device.

[0012] Another object of the invention is to specify a use for the improved braking device.

[0013] Another objective of the invention is to provide a vehicle with an improved braking system.

[0014] The object of the invention is to provide a method for generating a total braking torque.

[0015] DLR-4348WO

[0016] 2025-12-17 The problems are solved by the features of the independent claims. Favorable embodiments and advantages of the invention result from the further claims, the description and the drawing.

[0017] According to one aspect of the invention, a braking device for generating a total braking torque for a vehicle is proposed, comprising at least: an eddy current braking device, an energy storage device, at least one electric machine electrically connected to the energy storage device, and an actuator device, wherein the eddy current braking device has a stator part, a rotor part rotatably arranged 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 spaced apart from each other by an air gap, wherein the stator part comprises an excitation device configured to generate a primary magnetic field directed radially, and wherein an induction device is provided configured to induce eddy currents by a magnetic field, thereby generating a first braking torque.wherein the actuator is configured to generate a force by means of which the rotor part and the stator part can be displaced relative to each other, thereby creating contact between the stator part and the rotor part and generating a second braking torque, wherein the electric machine and / or the eddy current braking device are coupled, at least temporarily, to at least one wheel of the vehicle. The rotor part and the stator part can be arranged concentrically to each other.

[0018] Ideally, the eddy currents can be generated in the stator section. In this case, the induction unit can be located within the stator section. Alternatively, the induction unit can be designed so that the eddy currents are generated in the rotor section.

[0019] Because the electric machine and / or the eddy current braking device can be coupled or connected to at least one wheel of the vehicle, the kinetic energy of the electric machine and / or the eddy current braking device can be transferred to that at least one wheel. This allows a total braking torque to be generated.

[0020] DLR-4348WO

[0021] 2025-12-17 This allows a braking effect to be achieved on the wheel or multiple wheels of the vehicle. The eddy current braking device can come into operative contact with the wheel of the vehicle and exert a braking torque generated by friction.

[0022] The induction device can be assigned to the stator or rotor section. Wear-free braking can be achieved using the eddy current braking device, particularly the induction device, because the eddy currents generated in the induction device exert an additional braking torque and thus an additional braking effect. This allows the total braking torque to be generated, which consists of several braking contributions. This is a significant advantage over prior art braking devices that use friction linings to apply the braking torque. It eliminates the need for maintenance work, such as replacing worn friction linings, and thus reduces costs.

[0023] The eddy current braking system, with its excitation unit consisting of excitation coils and the stator section designed as a stator yoke, can also be used as a braking resistor to at least partially brake the vehicle. The electric machine can be used as a generator to supply energy, for example, directly or indirectly to the actuators or the excitation unit via an energy storage device and / or an energy storage system. This is advantageous because it can be done even when the vehicle's main energy storage system, such as a vehicle battery, is fully charged. The excitation unit can thus be used as an energy sink.

[0024] The energy storage device can be the vehicle's battery and / or a separate energy storage unit located in addition to the vehicle battery. Advantageously, the energy storage unit can be associated with the eddy current braking system and located adjacent to or within it. The energy storage unit can be small and designed to provide energy for the excitation system. Advantageously, its dimensions can provide the energy required to supply the excitation power for two to four full braking maneuvers.

[0025] DLR-4348WO

[0026] 2025-12-17 During emergency braking, the vehicle can be brought from its permitted maximum speed to a standstill with maximum utilization of the traction between the tires and the road surface.

[0027] The eddy current braking device can feature either axial or radial flux guidance and can function as an integrated friction brake. The following advantages can arise with radial magnetic flux guidance. Radial flux guidance avoids typical problems of axial flux machines, where the maximum rotational speed is limited by the yield strength or tensile strength of the material due to the large rotor diameter, high rotor mass, and typical disk shape.

[0028] Similarly, 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. Consequently, the power density is reduced at high speeds. The magnetic properties are also altered, and the braking device behaves differently than the underlying (design) simulation model. The predictive power of the model is limited. Radial flux guidance allows for a higher power density than eddy current braking devices with axial flux guidance.

[0029] Axial flux guidance can advantageously generate additional benefits, such as a reduced axial length and improved efficiency. A further advantage can lie in the simpler design of the stator section, for example, as a disk-shaped stator section.

[0030] The force that can cause the rotor to move towards the stator can be achieved by activating the actuator. The actuator can be activated by supplying it with energy. This energy can either be drawn from an energy storage device, such as a vehicle battery, or generated by an electric machine, such as a generator.

[0031] DLR-4348WO

[0032] 2025-12-17 Alternatively, the eddy current braking device can itself act as an actuator and generate the force due to the magnetic attraction forces between the stator part and the rotor part.

[0033] A frictional contact can be formed between an axially aligned friction element, in particular a brake disc, arranged on the rotor part and a friction element, in particular a brake pad, arranged on the stator part. This allows a friction pair to be realized during operation. In this way, the braking torque can be generated. The additional mechanism of eddy currents from the eddy current braking device can generate the additional braking torque and produce a torque until the system comes to a standstill. This allows the system to be decelerated advantageously until it comes to a standstill.

[0034] The rotor section can be implemented as an internal rotor within the stator section, allowing for a smaller design. The radial flux routing enables increased power density.

[0035] The rotor section can alternatively be implemented as an external rotor, whereby the stator-rotor arrangement can also be reversed, with the stator section located inside the rotor section. Accordingly, all arrangements, geometries, and orientations, for example, radially outward-facing pole elements, are also possible in reverse. The rotor section implemented as an external rotor can exhibit a higher power density.

[0036] In a favorable embodiment of the braking device, the actuator and excitation system are electrically connected to the electric machine and / or to the energy storage device. Advantageously, the energy storage device can include smaller energy storage units in addition to the vehicle battery. This allows for an alternative energy supply for the excitation and actuator systems. The state of charge of the energy storage device, particularly the vehicle battery, can be taken into account when controlling or selecting the energy supply. Generated energy can then be stored in the energy storage device(s). During operation, energy can be drawn from the respective energy storage device to power the excitation coils.

[0037] DLR-4348WO

[0038] 2025-12-17 In this context, an energy storage device can be assigned to each eddy current braking device arranged on a wheel. The assigned energy storage device can advantageously be arranged adjacent to or within this device.

[0039] In a further advantageous embodiment of the braking device, the electrical energy required for the actuator can be generated within the electric machine and / or drawn from the energy storage device. In this case, the electrical energy can be drawn from the energy storage device. This allows for the implementation of an alternative energy management strategy, for example, in a battery management system (BMS). Control can be achieved via the vehicle's on-board computer.

[0040] In a favorable embodiment of the braking device, the electric motor and / or the eddy current braking device can be coupled directly or via a gearbox, at least temporarily, to the at least one wheel. This allows the rotational speed and the technical design of the electric motor and the braking device according to the invention to be adapted.

[0041] In a favorable embodiment of the braking device, the energy storage system can comprise at least one, and in particular several, energy storage units. This allows for a higher storage capacity and / or a distributed storage capacity within the vehicle. Furthermore, redundancy can advantageously be achieved.

[0042] In a further advantageous embodiment of the braking device, at least one power electronics unit can be provided, which is electrically connected to the energy storage device and / or the electric machine. This allows for the conversion of electrical energy using switching electronic components. For example, the power electronics unit can be a frequency converter, an inverter, or, more generally, a switching regulator. The conversion from one voltage level to another can be performed, for example, from a 400 V voltage level to a 48 V voltage level or from a 48 V voltage level to a 120 V voltage level.

[0043] DLR-4348WO

[0044] 2025-12-17 In a further advantageous embodiment of the braking device, at least one of the energy storage units of the energy storage device can be charged by the electric machine by means of the at least one power electronics.

[0045] In a favorable embodiment of the braking device, the excitation unit can comprise excitation coils, wherein the excitation unit is made of aluminum or an aluminum alloy. Aluminum has a high specific heat capacity, typically 897 J / kgK. This allows the excitation coils to absorb more braking energy, enabling the excitation unit to store thermal energy and serve as an energy sink. The energy sink can be an electrical energy sink, since the excitation coils are supplied with electrical energy from the energy storage device or the electric motor. Within the excitation coils, an electrical excitation conductor can be converted into thermal energy through its ohmic resistance.The energy converted in the excitation coils can be at least partially braking energy if the electric machine simultaneously generates a braking torque and feeds it into at least one energy storage device from which the electrical energy for excitation is taken.

[0046] Excitation coils are typically wound from copper wire. Copper has a lower specific heat capacity of 380 J / kgK. Aluminum also has the advantage of being lighter than copper. The density of copper is 8.98 g / mm³. 2 The density of aluminum is 2.7 g / mm³ 2 The eddy current braking device can be made smaller because the excitation unit can store thermal energy. Overall, the excitation unit of the braking device can be used as an energy sink in addition to the brake disc.

[0047] In a further embodiment, the excitation coils can have a coil core and a winding, wherein the windings primarily consist of copper or aluminum and high-temperature insulation, in particular a fiberglass fabric, is arranged between adjacent turns of the copper or aluminum winding. The high-temperature insulation can be arranged between the individual turns of the winding.

[0048] DLR-4348WO

[0049] 2025-12-17 This allows them to be thermally insulated. Overall, the excitation coil can withstand a higher thermal load. This is advantageous because more braking energy can be thermally absorbed in the excitation device. The winding can be formed from a flat strip of copper and / or aluminum, in particular a copper or aluminum strip. The high-temperature insulation, which is arranged between two adjacent windings, can be made of or comprised of a high-temperature resistant material. This can be, for example, a fiberglass tape or fiberglass fabric. This is advantageous because fiberglass can withstand a temperature of 800°C. Furthermore, the copper or aluminum strip can also be wound around the outside of the excitation coil.

[0050] In a further advantageous embodiment, the copper and / or aluminum tape and the high-temperature insulation material, in particular the fiberglass fabric, can be bonded using a high-temperature adhesive, especially a ceramic adhesive. In this configuration, the copper and aluminum tape and the fiberglass fabric can be bonded together. A high-temperature adhesive can withstand temperatures up to 2000°C. This allows the winding to be subjected to thermal stresses close to the melting point of the winding material. The high-temperature adhesive can result in excellent cohesion of the materials within the excitation coil. Consequently, a very high braking energy can be absorbed.

[0051] In a favorable embodiment of the braking device, the actuator can be electrical, electromagnetic, or mechanical, or a combination thereof. This allows for a wide variety of possible designs with corresponding advantages. A mechanical actuator, for example, can be a spring mechanism. An electromechanical actuator can be an eddy current braking device in which a magnetic attraction force can be generated.

[0052] In a further advantageous embodiment of the braking device, the eddy current braking device can include a cooling system with a fluid and be cooled by means of the fluid. This allows for higher power outputs in the excitation system.

[0053] DLR-4348WO

[0054] 2025-12-17 In a favorable embodiment of the braking device, the actuator assembly can comprise or be the stator part and the rotor part, wherein the force is the magnetic attraction force between the stator part and the rotor part.

[0055] In a favorable embodiment of the braking device, the actuator assembly can comprise a hydrodynamic component, in particular a piston, and / or a mechanical component, wherein the force can be transmitted directly or via the mechanical component to the rotor part or the stator part, and thus the displacement between the stator part and the rotor part can be generated. The actuator assembly can be pressurized by the fluid.

[0056] Hydrodynamic components are robust and require little maintenance during vehicle operation.

[0057] In another advantageous embodiment of the braking device, the excitation unit can be actively cooled by means of the fluid. This allows the excitation coils of the excitation unit to absorb more power, which can be dissipated through cooling.

[0058] In one embodiment, the fluid can be used both in the cooling device and in the hydrostatic component, particularly the piston. This allows the fluid to circulate in both the coolant circuit and the pressurized circuit. Consequently, the fluid can simultaneously serve to cool and pressurize the piston or diaphragm, thus generating a force.

[0059] In one embodiment, the cooling device can include a coolant pump and an electrically actuated valve, wherein the coolant pump can be used to generate pressure and the electrically actuated valve is at least partially closed.

[0060] DLR-4348WO

[0061] 2025-12-17 The valve can advantageously be arranged downstream of a branch to the system, starting from the coolant pump. This allows the valve to be controlled so that it is partially closed, thereby increasing the pressure in the corresponding section of the line. This, in turn, generates the force. Overall, the pressure can advantageously be generated both by the valve control, particularly the valve position, and by the active pumping power of the coolant pump.

[0062] In a further aspect of the invention, a vehicle is proposed that has a braking device according to the invention, comprising at least one eddy current braking device, an energy storage device, and at least one electric machine. The energy storage device can include either a vehicle battery or separate, particularly smaller, energy storage devices. The smaller energy storage devices can be assigned to the respective eddy current braking device, which is arranged at each wheel of the vehicle.

[0063] In one embodiment, the vehicle has an on-board computer and at least one acceleration sensor for detecting at least one longitudinal acceleration of the vehicle. The measurement data from the acceleration sensor can be used to determine the required total braking torque.

[0064] The vehicle can be a motor vehicle, for example a passenger car or a truck. The vehicle can also be a rail vehicle, for example a train.

[0065] The braking device can be provided as a secondary braking device in addition to a mechanical braking device. The eddy current braking device can be integrated into the vehicle's drivetrain. Alternatively, the eddy current braking device can be arranged on a second drive shaft and function as a braking device. The eddy current braking device can be integrated into the vehicle's wheels. In this case, the energy storage device can also be integrated into the vehicle's wheels or located adjacent to them. This ensures an autonomous energy supply for the braking device.

[0066] DLR-4348WO

[0067] 2025-12-17 One advantage of the proposed braking device installed in the vehicle is that the vehicle can be braked to a complete standstill.

[0068] This can be achieved through an interaction of the actuator devices and, in particular, the friction element of the eddy current braking device, which forms an integrated friction brake.

[0069] In a favorable embodiment of the vehicle, the eddy current braking device can comprise at least one stator part, a rotor part rotatably arranged relative to the stator part about an axis of rotation, with a shaft arranged in the axis of rotation, and an actuator device, wherein the rotor part and the stator part are arranged concentrically to each other with an air gap between them, wherein the stator part comprises an excitation device configured to generate a primary magnetic field, wherein an induction device is provided which is configured to induce eddy currents by a magnetic field, thereby generating a first braking torque, and wherein the actuator device is configured to generate a force by means of which the rotor part and the stator part can be displaced relative to each other, thereby generating contact between the stator part and the rotor part and generating a second braking torque.wherein the eddy current braking device and / or the electric machine are coupled at least temporarily to at least one wheel of the vehicle.

[0070] A key advantage is that the eddy current braking system can operate largely wear-free thanks to the induction generated in the induction unit. Furthermore, the eddy current braking system can be integrated into the vehicle's wheel. The generation of braking torque through contact between the rotor and stator sections creates a frictional force that brings the vehicle to a standstill.

[0071] In a favorable vehicle configuration, a brake pedal can be provided by means of which braking pressure can be generated. In this case, the vehicle can have an electric motor and an internal combustion engine.

[0072] DLR-4348WO

[0073] 2025-12-17 In a favorable vehicle configuration, the on-board computer can be set up to determine the current acceleration value from the brake pedal position, brake pressure, or pedal force, and / or to send the current speed value as a signal to the power electronics of the braking system. This allows the required total braking torque to be determined.

[0074] In a favorable vehicle design, a parking brake can be provided. This allows the rotation of a part rigidly coupled to the vehicle's wheel to be blocked. This provides a dual braking option for the vehicle.

[0075] The parking brake can be implemented by a locking mechanism on a gear pinion of the vehicle's transmission, with the gear pinion being torsionally rigidly coupled to at least one wheel. The parking brake function can be implemented by an actuator. Alternatively, the parking brake function can be implemented by pressing the rotor part against the stator part.

[0076] In a further aspect of the invention, the use of a braking device according to the invention in a vehicle equipped for autonomous driving is proposed. An autonomous vehicle can be a vehicle without a brake pedal. In this case, the braking force can be generated via the on-board computer.

[0077] In a further aspect of the invention, a method for generating a total braking torque in a vehicle is proposed, wherein the total braking torque is composed of a braking torque from an eddy current braking device and an electric machine, for example, an electric motor or generator. This allows two independently generated braking torques to be realized. This is advantageous for safety reasons.

[0078] DLR-4348WO

[0079] 2025-12-17 In a favorable design, the procedure may include the following steps:

[0080] Determining the required total braking torque,

[0081] Determining the maximum braking torque of the electric machine, in particular the motor of the vehicle,

[0082] Determining the required braking torque of the eddy current braking device and the generator,

[0083] Data transmission of the determined braking torque of the

[0084] Eddynamite current braking device and of the motor to each of the computer of the respective power electronics,

[0085] Determining the required excitation current for the excitation circuit of the eddy current braking device and the required current for the actuator; determining the required electrical signal for controlling the power semiconductors of the power electronics.

[0086] Generating the detected electrical signal and forwarding it to at least one power electronics unit.

[0087] The required total braking torque can be determined using the brake pedal position and sensor data from acceleration and speed sensors. Alternatively, the total braking torque can be determined using the target deceleration calculated by the onboard computer of an autonomous vehicle and sensor data from acceleration and speed sensors.

[0088] A simplest version of the procedure may include the following steps:

[0089] Determining a target speed

[0090] Determining the correct signals for controlling the power electronics of the eddy current friction brake and the electric machine; generating the signals for controlling the power electronics

[0091] The target speed can be determined by a person and / or by the on-board computer.

[0092] DLR-4348WO

[0093] 2025-12-17 In a favorable embodiment of the method, the determined electrical signal can be forwarded to a power semiconductor and transmitted to the eddy current braking device by means of the first power electronics and / or second power electronics.

[0094] A signal can be generated, or several signals can be generated, which, at a given time, switch the power semiconductors on or off based on the target and actual value of the current.

[0095] In another favorable embodiment of the method, the electrical signal can be a pulse width modulation signal (PWM signal).

[0096] In general, the rotor part in which the eddy currents can be generated can have structures as described in publications WO2024088476A1 and WO202408477A1.

[0097] It is advantageous if the induction device of the eddy current braking device is designed to generate a secondary magnetic field that is directed at least partially in the opposite direction to the primary magnetic field in the radial direction as a result of a rotation of the rotor part about the axis of rotation.

[0098] Advantageously, the induction device can comprise a substantially ring-shaped base body with a plurality of pole elements directed radially to the rotor part and an electrically conductive element which at least partially encloses the pole elements.

[0099] It can be advantageous if the base body comprises an electrical steel sheet stack with electrical steel sheets stacked in the axial direction or is designed as an electrical steel sheet stack with electrical steel sheets stacked in the axial direction.

[0100] The electrically conductive element can comprise electrically conductive individual laminations that enclose the pole elements and are arranged radially, essentially concentrically to one another. The electrically conductive individual laminations can be ring-shaped. Electrical steel sheets are relatively easy to manufacture. This advantageously reduces the disruptive skin effect.

[0101] DLR-4348WO

[0102] 2025-12-17 Furthermore, the electrically conductive individual sheets can be designed as sheet metal strips, wherein adjacent sheet metal strips, particularly at their end faces, are electrically connected to one another, in particular by soldering or welding. The spacing between the individual electrical steel sheets in the radial direction allows for favorable flow of a coolant in the axial direction.

[0103] Advantageously, the electrically conductive element can comprise at least one electrically conductive sheet metal strip which has a plurality of through-holes for the plurality of pole elements, wherein the electrically conductive sheet metal strip is spirally wound around the axis of rotation onto the plurality of pole elements.

[0104] It can be advantageous if the electrically conductive element comprises an electrically conductive foam that encloses the majority of the pole elements. For the purposes of the present invention, an electrically conductive foam is understood to be a porous structure permeated by a multitude of pores. Within the structure, pores form hollow bodies and / or cavities that are separated from one another by struts, in particular solid struts. The porous structure is, in particular, a two-phase system that may consist of a solid and a gaseous phase and / or a solid and a liquid phase.

[0105] The metallic, electrically conductive material of the porous structure exhibits, in particular, an electrical conductivity of at least 2 10 6 S / m (relative to room temperature) and is, for example, a metal. Ideally, the foam can be made of aluminum or at least contain aluminum.

[0106] Advantageously, the axial side surfaces of the pole elements can be inclined at an angle to the axial direction. Due to the magnetic flux density, an axial attracting force can be generated between the stator and rotor parts. This force causes an axial displacement of the rotor part after overcoming the preload force of the spring element, thus establishing contact between the friction pair of the two friction elements between the stator and rotor parts.

[0107] DLR-4348WO

[0108] 2025-12-17 This can create an additional frictional torque. Thus, an inherent disadvantage of the purely electrodynamic eddy current brake can be compensated for, and a torque can be generated that allows the eddy current brake to be brought to a standstill.

[0109] It can also be advantageous if the excitation device comprises an excitation base body enclosing the shaft with a plurality of excitation pole elements directed radially to the stator part, in particular each excitation pole element comprising an electrical excitation coil. The excitation base body can comprise a second electrical steel stack with individual laminations stacked in the axial direction, or be designed as a second electrical steel stack with individual laminations stacked in the axial direction.

[0110] The electrical excitation coils can be designed for electrical coupling with an electrical control unit.

[0111] It can also be advantageous if a number of pole elements directed radially to the rotor part and a number of excitation pole elements directed radially to the stator part differ by no more than 50%.

[0112] Advantageously, the electrically conductive element can have one or more coolant paths designed for the flow of coolant. Furthermore, one or more slip-ring rotary transmitters can be provided for transmitting an excitation current to the excitation device arranged on the rotor part.

[0113] When using a braking system in a heavy vehicle, such as a truck, where the braking system must be able to maintain a constant speed when driving downhill without overheating the brakes, the use of an eddy current braking system is advantageous. In particular, in an electrically powered truck with an electric motor, the electric motor can be used to thermally relieve the mechanical friction brake by feeding the braking energy into the energy storage system via the electric motor, especially the generator, or by using the generated energy directly as an energy source for the actuators or the excitation coils of the excitation device.

[0114] DLR-4348WO

[0115] 2025-12-17 This circumvents the disadvantage of conventional braking devices according to the state of the art, where this is not possible once the energy storage device is fully charged.

[0116] The braking effect is not solely based on friction, as with conventional braking devices, because the braking torque generated by eddy currents can also be utilized. This can result in the braking device being less prone to wear overall.

[0117] Due to its smaller design and the use of aluminum in the excitation device, the brake device can be installed in at least one wheel of the vehicle.

[0118] In summary, the advantages of the braking device according to the invention are listed.

[0119] drawing

[0120] 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. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0121] They show, for example:

[0122] Fig. 1 is an isometric representation of an eddy current braking device;

[0123] Fig. 2 shows a possible physical embodiment of the eddy current braking device;

[0124] Fig. 3 is an isometric representation of the eddy current braking device of Figure 1 with power supply equipment;

[0125] Fig. 4 shows a top view of a vehicle with a braking device with the eddy current braking device from Figure 1 and Figure 2;

[0126] DLR-4348WO

[0127] 2025-12-17 Fig. 5, 6 Side views of embodiments of an actuator element of an actuator;

[0128] Figs. 7, 8, 9, 10 Side views of various embodiments of actuators;

[0129] Fig. 11 shows a top view of a coolant circuit;

[0130] Figs. 12, 13, 14, 15 Side views of different embodiments of the connections between actuator and stator part;

[0131] Figs. 16, 17, 18 Side views of different embodiments of mechanical elements;

[0132] Figs. 19, 20, 21 Side views of the actuator with a threaded drive;

[0133] Figs. 22, 23, 24 Side views of the actuator with a lifting magnet device;

[0134] Fig. 25 shows a schematic representation of a process scheme for

[0135] Generation of a braking torque,

[0136] Fig; 26 a schematic representation of a process scheme of a simplified embodiment for generating a braking torque;

[0137] Fig. 27 shows a schematic representation of a process scheme of a simplified embodiment for generating a braking torque using a driver assistance system;

[0138] Fig. 28 schematic representation of the excitation coil in a high-temperature embodiment.

[0139] Embodiments of the invention

[0140] In the figures, similar or equivalent components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0141] Before the invention is described in detail, it should be noted that it is not limited to the individual components of the device, as these components can vary. The terms used here are intended solely to describe particular embodiments and are not used restrictively. Furthermore, where the singular or indefinite articles are used in the description or in the claims, this also refers to the plural of these elements, unless the overall context clearly indicates otherwise.

[0142] DLR-4348WO

[0143] 2025-12-17 The directional terminology used below, including terms such as "left," "right," "above," "below," "in front," "behind," "after," and the like, serves only to improve the understanding of the figures and is in no way intended to limit their generality. The components and elements depicted, their interpretation, and their use may vary according to the considerations of a person skilled in the art and be adapted to the respective applications.

[0144] Figure 1 shows a schematic representation of an eddy current braking device 10 for a vehicle 42, which is shown in Figure 4.

[0145] The eddy current braking device 10 comprises a stator part 12 with a yoke 13, and a rotor part 16 rotatably arranged relative to the stator part 12 about a rotational axis 14. The eddy current braking device 10 has a shaft 18 arranged in the rotational axis 14.

[0146] Figure 1 shows an axial configuration of the eddy current braking device 10. The components rotor part 16 and stator part 12 are arranged axially along the axis of rotation 14. The rotor part 16 is spaced apart from the stator part 12 by an air gap 20. The stator part 12 comprises an excitation device 22, which is designed to generate a primary magnetic field (not shown). The excitation device 22 has excitation coils 21, one of which, with an energy storage device 23, is shown schematically in the upper left of Figure 1. The excitation current of the excitation coil 21 is designated by the reference numeral 25. The eddy current braking device 10 has a radial or axial flux guide.

[0147] The excitation coils 21 are manufactured in several embodiments. In a first embodiment, the excitation coils 21 of the excitation device 22 are essentially made of aluminum. Aluminum has a high specific heat capacity, typically 897 J / kgK. This allows the excitation coils 21 to absorb more braking energy. As standard, excitation coils 21 are wound from copper wires. Copper has a significantly lower specific heat capacity of 380 J / kgK than aluminum. This allows the excitation coils 21 of the excitation device 22 to absorb more braking energy during vehicle operation 42.

[0148] DLR-4348WO

[0149] 2025-12-17 As standard, excitation coils 21 are wound from copper wires. Aluminum also has the advantage of being lighter than copper. The density of copper is 8.98 g / mm², while the density of aluminum is 2.7 g / mm². The eddy current braking device 10 is therefore lighter.

[0150] A second embodiment of the excitation coil 21, which is referred to as the high-temperature excitation coil 21, is described in more detail in Figure 28.

[0151] The excitation device 22 is supplied with electrical energy, for example, from an energy storage device 24 and / or from the energy storage device 23.

[0152] The energy storage device 24 can, for example, include or be a vehicle battery (vehicle battery). The energy storage device 23 can be part of the energy storage device 24.

[0153] The energy storage device 23 can also be designed independently of the energy storage unit 24, in which case the energy storage device 23 is not connected to the energy storage unit 24, but is a separate, autonomous energy storage device 23. The energy storage unit 24 can also be part of a system of energy storage devices (see the description for Figure 3). The energy storage unit 24 and / or the energy storage device 23 are / are electrically connected to a first power electronics unit 26 (shown in Figure 3).

[0154] The dimensions of the energy storage device 23 are chosen such that the energy stored in the energy storage device 23 corresponds to the time integral of the necessary excitation power for two to four full braking maneuvers from the vehicle's maximum permissible speed to a standstill, with maximum utilization of the traction between the tires and the road surface. This means that the energy storage device 23 is dimensioned such that the excitation power for two to four full braking maneuvers can be provided over the braking cycle.

[0155] DLR-4348WO

[0156] 2025-12-17 The eddy current braking device 10 further comprises at least one first actuator 28 by means of which a force 30 can be exerted. By means of the force 30, the rotor part 16 and the stator part 12 are arranged to be displaceable relative to each other, in particular displaceable on the shaft 18.

[0157] The rotor part 16 and the stator part 12 can be moved towards each other by means of the force 30 if the actuator 28 is supplied with energy.

[0158] A second actuator 32 can exert a force 34 during operation. By means of the force 34, the stator part 12 can be moved relative to the rotor part 16 in a direction opposite to the force 30. This prevents a frictional pairing from forming between the rotor part 16 and the stator part 12, which can arise from a magnetic attraction force 38 between the stator part 12 and the rotor part 16.

[0159] The force 34 can alternatively be generated by means of a mechanical device 36, for example a spring device 36.

[0160] Each section of a fluid channel 40 is designated as a part of a coolant circuit 58, which may include a further actuator. The actuator is a fluid-operated actuator, and reference is made to the description in Figure 7.

[0161] An induction device (not shown) is provided, which is designed to induce eddy currents by means of a magnetic field. The induction device can be arranged either in the stator part 12 or in the rotor part 16. The induction device is designed to generate a secondary magnetic field that is directed at least partially opposite to the primary magnetic field resulting from the rotation of the rotor part 16 about the axis of rotation 14. In its simplest embodiment, the induction device comprises a magnetic field-generating element and an electrically conductive element that can move within the magnetic field. The induction device includes excitation coils 21, which can generate a magnetic field by means of the excitation current 25.

[0162] DLR-4348WO

[0163] 2025-12-17 In one embodiment, the induction device typically has a substantially ring-shaped base body comprising an electrical steel stack with electrical steel sheets stacked in the axial direction, or is designed as an electrical steel stack with electrical steel sheets stacked in the axial direction. The electrically conductive element comprises electrically conductive individual sheets that enclose the pole elements and are arranged substantially concentrically to one another in the radial direction. The electrically conductive individual sheets may be ring-shaped.

[0164] The electrically conductive individual sheets are designed as sheet metal strips, wherein adjacent sheet metal strips, in particular at end faces, are electrically connected to each other, in particular soldered or welded.

[0165] The base body comprises a plurality of radially inwardly directed pole elements and the electrically conductive element, which at least partially encloses the pole elements.

[0166] In a radial arrangement, the rotor part 16 is arranged radially within the stator part 12, spaced apart from it by an air gap 20. The stator part 12 comprises the excitation device 22, which is designed to generate a primary magnetic field (not shown) directed radially. The excitation device 22 includes the excitation coils 21, of which the excitation coil 21 is shown schematically. The excitation current of the excitation coil 21 is designated by the reference numeral 25.

[0167] The excitation coils 21 of the excitation device 22 are essentially made of aluminum. Aluminum has a high specific heat capacity, typically 897 J / kgK. This allows the excitation coils 21 to absorb more braking energy. As standard, the excitation coils 21 are wound with copper wire. Copper has a significantly lower specific heat capacity of 380 J / kgK than aluminum. This allows the excitation coils 21 of the excitation device 22 to absorb more braking energy during vehicle operation 42. As standard, the excitation coils 21 are wound with copper wire. Furthermore, aluminum has the advantage of being lighter than copper. The density of copper is 8.98 g / mm³. 2 The density of aluminum is 2.7 g / mm³ 2 The eddy current braking device 10 therefore has a lower weight.

[0168] DLR-4348WO

[0169] 2025-12-17 The excitation device 22 is supplied with electrical energy, for example, from the energy storage device 24 and / or the energy storage unit 23. The energy storage device 24 can, for example, include or be a vehicle battery. The energy storage unit 23 can be part of the energy storage device 24. Alternatively, the energy storage unit 23 can be designed as an autonomous energy storage unit 23, independent of the energy storage device 24. In this case, the energy storage unit 23 is not connected to the energy storage device 24, but is a separate, autonomous energy storage unit 23. However, in this case, the reference numeral 24 merely represents a connection unit to the vehicle battery.The energy storage device 24 can be part of a system of energy storage devices (see the description for Figure 3), and thus only a small partial energy storage device can be arranged at the location marked with the reference numeral 24. The energy storage device 24 and / or the energy storage device 23 are / are electrically connected to a first power electronics unit 26 (shown in Figure 3).

[0170] The eddy current braking device 10 further comprises at least one first actuator 28 by means of which a force 30 can be exerted. By means of the force 30, the rotor part 16 and the stator part 12 are arranged to be displaceable relative to each other, in particular displaceable relative to the shaft 18. In the radial embodiment, the rotor part 16 and the stator part 12 are arranged to be displaceable radially relative to each other. The rotor part 16 and the stator part 12 can be moved towards each other by means of the force 30 if the actuator 28 is supplied with energy.

[0171] A second actuator 32 can exert a force 34 during operation. By means of the force 34, the stator part 12 can be moved relative to the rotor part 16 in a direction opposite to the force 30. This prevents a frictional pairing from forming between the rotor part 16 and the stator part 12, which could arise from a magnetic attraction force 38 between the stator part 12 and the rotor part 16. Alternatively, the force 34 can be generated by a mechanical device 36, for example, a spring device 36.

[0172] DLR-4348WO

[0173] 2025-12-17 Arrows 40 each indicate a part of a coolant circuit 58, which may include a further actuator. The actuator is a fluid-operated actuator, and reference is made to the description in Figure 7.

[0174] The induction device (not shown) is provided, which is designed to induce eddy currents by means of a magnetic field. The induction device can be arranged either in the stator part 12 or in the rotor part 16. The induction device is designed to generate a secondary magnetic field that is directed radially opposite to the primary magnetic field as a result of rotation of the rotor part 16 about the axis of rotation 14, at least in certain areas. In its simplest embodiment, the induction device comprises a magnetic field-generating element and an electrically conductive element that can move within the magnetic field. The induction device includes excitation coils 21, which can generate a magnetic field by means of the excitation current 25.

[0175] The eddy current braking device 10 can be configured as an internal rotor in the radial embodiment, in which the rotor part 16 is arranged radially inside the stator part 12. In the case of an external rotor configuration of the eddy current braking device 10, the stator-rotor arrangement can be reversed, with the stator part 12 arranged inside the rotor part 16.

[0176] Accordingly, all arrangements, geometries and orientations are also possible in reverse, e.g., radially outward-facing pole elements.

[0177] Figure 1 shows the eddy current brake 10 only schematically, with the elements stator part 12 and rotor part 16, and does not depict a radial embodiment. The induction device typically has a substantially ring-shaped base body that comprises an electrical lamination stack with electrical laminations stacked in the axial direction, or is designed as an electrical lamination stack with electrical laminations stacked in the axial direction. The electrically conductive element comprises electrically conductive individual laminations that enclose the pole elements and are arranged substantially concentrically to one another in the radial direction. The electrically conductive individual laminations may be ring-shaped.

[0178] DLR-4348WO

[0179] 2025-12-17 The electrically conductive individual sheets are designed as sheet metal strips, wherein adjacent sheet metal strips, in particular at end faces, are electrically connected to each other, in particular soldered or welded.

[0180] The base body comprises a plurality of radially inwardly directed pole elements and the electrically conductive element, which at least partially encloses the pole elements.

[0181] Figure 2 shows a schematic representation of a diagram taken from the publication https: / / ieeexplore.ieee.org / stamp / stamp.jsp?tp=&arnumber=6662394

[0182] Eddy current braking device 710, which is intended to illustrate a possible radial geometric arrangement of the stator part 12 and the rotor part 16 of the eddy current braking device 10. The items are designated with the prefix 7 for differentiation.

[0183] The eddy current braking device 710 comprises a stator part 712 and a rotor part 716, which are arranged concentrically around a shaft 718. An excitation coil arrangement 721 associated with the stator part 712 is shown. The eddy current braking device 712 has a cooling system 740, of which an inlet 742 and an outlet 744 are shown.

[0184] Figure 3 shows a schematic representation of the eddy current braking device 10 from Figure 1 with power supplies (see Figure 4) including the associated power electronics for the actuators 28 and 32. The power supply includes the energy storage device 24 and / or the energy storage device(s) 23. The energy storage devices 23 can be arranged in the vehicle 42 and / or adjacent to a wheel 44 (not shown) (see Figure 4). The excitation coils 21 of the excitation device 22 are supplied with energy by the power electronics 310. The voltage level in the power electronics 310 is adjusted to the required voltage level of the excitation coils 21. The actuator 28 is supplied with energy by a power electronics unit 320.

[0185] DLR-4348WO

[0186] 2025-12-17 The actuator 32 is powered by a power electronics unit 330. Different voltage levels can be achieved by using different power electronics units for the excitation coils 21 and the actuators 28 and 32, even if the energy is taken from a single power source.

[0187] Figure 4 shows a schematic top view of a vehicle 42 with the braking device 200, which includes the eddy current braking device 10. The eddy current braking device 10 is typically integrated into each wheel 44 of the vehicle 42. Typically, the vehicle 42 has four wheels 44 and four eddy current braking devices 10. Two wheels are connected to each axle 45. Each eddy current braking device 10 can include an energy storage device 23. In an alternative embodiment, each axle 45 can be assigned an energy storage device 23, so that the vehicle 42 has two energy storage devices 23. Furthermore, the vehicle has at least one electric machine 46, which can function both as a motor and as a generator 48.

[0188] The generator 48 is electrically connected to a second power electronics unit 50, which in turn is electrically connected to the energy storage device 23 or the energy storage unit 24 and can feed the generated energy into the energy storage unit 24 or the energy storage device 23 during operation of the vehicle 42. The generator 48 is in turn electrically and / or mechanically connected to a gearbox 52, which in turn is connected to a parking brake 54.

[0189] The parking brake 54 is mechanically and / or electrically connected to at least one of the eddy current braking devices 10. The parking brake 54 is designed to block the rotational movement of an element (not shown) that is rigidly coupled to the wheel 44. The element rigidly coupled to the wheel 44 can, for example, be the stator part 12 of the eddy current braking device 10. The parking brake 54 can include the actuator 26 or the spring assembly 36. The parking brake 54 is connected to the axle 45 of one of the wheels 44 such that a braking torque can be exerted on the wheel 44.

[0190] DLR-4348WO

[0191] 2025-12-17 The vehicle 42 has an acceleration sensor 56 which is connected to the eddy current braking device 10. The acceleration sensor 56 is connected to a computer 300, in particular a microcomputer 300. The connection between the acceleration sensor 56 and the eddy current braking device 10 is typically electrical via the computer 300 or can be established by means of optical data transmission. The vehicle 42 also has a brake pedal 62. Alternatively, the braking effect can be achieved by a network of computers 300, in particular a microcomputer 300.

[0192] The latter is typically used in autonomous driving. If a brake pedal is present, a brake pedal position, brake pressure, or pedal force is used. The array of computers 300 is connected to the power electronics 26, 50, 310, 320, 330, 340, and 350; thus, brake torques 120, 122 calculated in the array of computers 300 can be transmitted to the corresponding power electronics 26, 50, 310, 320, 330, 340, and 350.

[0193] Figure 4 schematically shows a cooling system 58, which also serves as a coolant circuit 58 for the excitation coils of the excitation device 22, wherein the coolant system 58 comprises at least one coolant pump 60 and a valve assembly 63. The coolant circuit 58 can be used, for example, to actively cool the excitation coils of the excitation device 22. The coolant circuit 58 can also be a component of the actuators 28 and / or 32.

[0194] Figures 5 and 6 show schematic representations of two embodiments for an actuator element 64 and an actuator element 65 of the actuator 28 and / or the actuator 32. In a first embodiment shown in Figure 4, the actuator element 64 has at least one piston 66 which can be pressurized by a fluid 68. The piston 66 can transmit the force 30 either directly or via a first mechanical element 74 to the stator part 12 of the eddy current braking device 10. This causes the stator part 12 to be displaced relative to the rotor part 16 and is prevented from moving due to magnetic attraction forces 38.

[0195] DLR-4348WO

[0196] 2025-12-17 In a second embodiment shown in Figure 5, the actuator element 65 has a diaphragm 76 which can be pressurized by the fluid 68. This allows the force 30 to be generated, which is transmitted directly or via the first mechanical element 74 to the stator part 12. The pressurization can be carried out using the coolant pump 60 of the coolant system 58. Other embodiments of the pressurization are shown in Figures 11 and 12 to 15. The coolant system 58 serves simultaneously as a coolant circuit for cooling the excitation device 22 and for generating pressure for the actuator elements 64, 65 of the actuators 28, 32.

[0197] Actuator 28 and / or actuator 32 each have two of the actuator elements 64, 65 shown in Figure 5. These elements can be either two coupled actuator elements 64, two actuator elements 65 coupled by a line 80, or one actuator element 64 and one actuator element 65, with the actuator element 64 and the actuator element 65 being coupled by the line 82. "Coupled" refers to a fluidic connection whereby the fluid 68 can flow from one actuator element 64, 65 to the other actuator element 64, 65.

[0198] The four different possibilities of realizing the actuators 28 and 32 by a combination of the actuator elements 64 and 65 are shown schematically in Figures 7, 8, 9 and 10.

[0199] Figure 11 shows a schematic representation of the coolant circuit 58 with integrated actuator 28. The flow of the fluid 68 can be interrupted by means of the coolant valve 63. The actuator 28 and / or the actuator 32, each composed of the actuator element 64 or the actuator element 65, act on the rotor part 16 by means of the force 30 and / or the force 34.

[0200] The coolant circuit 58 is pressurized by a first mechanical element 78.

[0201] DLR-4348WO

[0202] Figures 12 to 15 of 2025-12-17 show a schematic representation of another embodiment of the actuators 28 and 32. In this embodiment, the actuator element 64 and / or the actuator element 65, which pressurizes the coolant circuit 58, has differently designed mechanical elements 82. The mechanical element 82 has either a threaded drive (see Figure 17) or a solenoid system (Figure 18).

[0203] Figures 16 to 18 show schematic representations of different connection options between the actuator 28, 32 and the stator part 12. The connection 84 shown in Figure 16 is a direct connection and has a rigid, linear component 86 which is coupled to the piston 66 or the diaphragm 76. The connection 88 shown in Figure 17 is designed as a toggle lever and has a toggle lever component 90 which has at least two straight elements 92 that are connected by means of a hinge element 94 and which transmits the force 30, 34 to the stator part 12.

[0204] Another component 96, in particular a straight component 96, can be connected to the piston 66. Another straight element 98 is fixed. A guide element 99 ensures that the straight element 92, which is connected to the stator part 12, is always perpendicular to it. The connection 100 shown in Figure 18 is designed as a cam mechanism and, in addition to the straight element 92, has a return spring 102 and a cam body 104.

[0205] The curved body 104 is connected to the stator part 12 via the straight component 92.

[0206] Figures 19 to 21 schematically depict the mechanical element 82 with a threaded drive and the connections 84, 88, and 100. A threaded spindle 102 is connected to an electric motor 106. Optionally, a thread 108 is arranged between the electric motor 106 and the threaded spindle 102. A threaded nut 110 is provided in the mechanical element 92 with the cam drive for fixing it. The electric motor 106 is connected to a power electronics unit 310, 320, or 330.

[0207] DLR-4348WO

[0208] Figures 22 to 24 of 2025-12-17 show a schematic representation of the mechanical element 82 with a lifting magnet 112. The lifting magnet 112 is connected to the stator part 12 by means of connection 84, connection 88 or connection 100. The lifting magnet 112 is connected to the power electronics 310, 320 or 330 and is supplied with electrical energy in this way.

[0209] Figure 25 shows a flowchart for a process 400, a process 500, and a process 600 for generating a braking torque, in particular a total braking torque. The components of the vehicle 42 involved in the respective process steps are also shown in Figure 25. The dashed arrows each denote a data flow. The double arrows each denote a physical effect of the respective process step.

[0210] Reference numeral 300 designates a system of computers on which the individual process steps are executed. Reference numerals 310, 320, and 330 designate different power electronics to which the respective electrical signal can be transmitted.

[0211] The method 400 is designed to generate a total braking torque in the vehicle 42, wherein the total braking torque is composed of a braking torque of the eddy current braking device 10 and the electric machine 46, 48, for example the electric motor or the generator 48.

[0212] Procedure 400 comprises the following steps:

[0213] S410: Start of procedure 400,

[0214] S420: Determining the required total braking torque,

[0215] S430: Determining the maximum braking torque of the electric

[0216] Machine(s) 46, for example the engine(s) of the vehicle 42,

[0217] S440: Determining the required braking torque of the eddy current braking device 10 and the generator 48,

[0218] S450: Transferring the determined braking torque of the

[0219] Eddy current braking device 10 and of the motor, to the computer of the respective power electronics,

[0220] DLR-4348WO

[0221] 2025-12-17 S460: Determining a required excitation current for the excitation device 22 of the eddy current braking device 10 and the required current for the actuator 28, 32, in particular for the electric motor 106 of the actuator 28, 32,

[0222] S470: Determining a required electrical signal to set the power semiconductors of the power electronics 310, 320 or 330,

[0223] S480: Generating the detected electrical signal and forwarding it to at least one power electronics unit (310, 320, 330), S490: Terminating the procedure.

[0224] In method 400, the determined electrical signal is forwarded to a power semiconductor 315, 325, or 335 of the power electronics 310, 320, or 330 and transmitted to the eddy current braking device 10 via the power electronics 310, 320, or 330 and / or to the power electronics 340, or a power semiconductor 345 of the power electronics 340. The energy fed into the power electronics can be drawn from the energy storage device 23 and / or the energy storage unit 24.

[0225] Arrow 118 indicates the currents supplied to the electrical machine 46. One or more electrical signals can be generated, which, based on the target and actual current values, switch the power semiconductors on or off at a given time.

[0226] The electrical signal is typically a pulse width modulation signal (PWM signal).

[0227] Method 500 describes the process steps that are carried out to determine the currents for power semiconductors 355 of the power electronics 350, which is connected to the energy storage device 24 or the energy storage device 23 or the electrical machine 46, for example the generator 48.

[0228] In process step S510, the necessary currents for the electrical machine 46, for example the motor 46 or the generator 48, are determined using the computer 300.

[0229] DLR-4348WO

[0230] 2025-12-17 In process step S520, the necessary pulse width modulation signal (PWM signal) is determined, which is needed to control the power semiconductors 355 of the power electronics 350.

[0231] In process step S530, the pulse width modulation signal for the power semiconductors is generated. The PWM signal is then passed on to the respective power semiconductor, which in turn controls the electrical machine.

[0232] In process 600, PWM signals are also determined in process steps S610 and S620, which are needed to control the power semiconductors 345 of the power electronics 340, and in process step S620 the necessary electrical signals, in particular the PWM signals, are generated.

[0233] A braking torque 120 is transmitted from the eddy current braking device 10 to the vehicle 42, in particular to the wheels 44. Furthermore, a braking torque 122 is transmitted from the electric machine 46 to the vehicle 42, in particular to the wheels 44.

[0234] Figure 26 shows a block diagram of a simplified method 800 for determining the required total braking torque for the vehicle 42 with the brake pedal 62, wherein the brake pedal 62 is operated by a person. The method 800 comprises at least the following steps:

[0235] Step S810: Detecting the position of the brake pedal 62 in the vehicle 42 (brake pedal position) or the pedal force or detecting a quantity that allows conclusions to be drawn about the pedal force, the brake pedal position;

[0236] S820 Multiplication of pedal force or brake pedal position by a factor;

[0237] S830: Calculate the required total braking torque.

[0238] Figure 27 shows a method 900 for determining the required total braking torque M geS soii for vehicle 42 using a driver assistance system. Procedure 900 comprises at least the following steps:

[0239] DLR-4348WO

[0240] 2025-12-17 S910: Mathematical derivation of a target value trajectory of the speed of vehicle 42 for a current time and a latency time;

[0241] S920: Determination of the current gradient of the road surface based on

[0242] Acceleration data

[0243] S930: Calculation of the target total moment M geS soii with equation 1.

[0244] Equation 1 :

[0245] Equation of motion for vehicle 42:

[0246] This includes v soll Target speed m: Vehicle mass

[0247] M_total_target: Target total moment r dyn : Dynamic tire radius c w : drag coefficient

[0248] A f : Projected frontal area of ​​vehicle g: Gravitational acceleration c r : Rolling resistance coefficient ot istCurrent gradient of the road

[0249] Figure 28 shows a second embodiment of the excitation coil 21. In this embodiment, the excitation coil 21 is a high-temperature excitation coil 21. The excitation coil 21 of the second embodiment is designed to withstand high temperatures. The excitation coil 21 has a high-temperature-resistant insulating material. The high-temperature-resistant insulating material is typically a woven glass fiber fabric, in particular a woven glass fiber fabric.

[0250] DLR-4348WO

[0251] 2025-12-17 The excitation coil 21 comprises a coil core 124 around which a winding 126 is arranged. The winding 126 has turns and consists of a flat strip of copper or aluminum, with a strip of insulating material, for example glass fiber, such as woven glass fiber, arranged between two adjacent turns. The woven glass fiber is arranged between each turn of the winding 126.

[0252] During winding, the fiberglass tape is sprinkled, coated, or impregnated with high-temperature-resistant adhesive. The high-temperature-resistant adhesive ensures the overall cohesion of the winding 126. The winding 126 is typically arranged on a support element 128.

[0253] Furthermore, a copper or aluminum strip 130 is arranged on an outer surface 132 of the support element 128. An insulating material 134 made of a woven glass fiber fabric is arranged on the copper or aluminum strip 130. A high-temperature adhesive 136 is arranged between the copper or aluminum strip 130 and the insulating material 134, bonding the two together.

[0254] The fabric tape (e.g. fiberglass fabric) has the task of preventing contact between two windings and, secondly, it serves as a carrier matrix for the adhesive and prevents potential "crumble" of the adhesive.

[0255] Fiberglass can withstand temperatures of up to 800°C and ceramic adhesives up to 2000°C. Therefore, the winding can theoretically be operated at temperatures close to the melting point of the winding material.

[0256] The excitation coil 21 in the high-temperature version makes it possible to achieve an increased absorption capacity for braking energy.

[0257] DLR-4348WO

[0258] December 17, 2025: In the prior art, attempts are made to operate the winding of an electromechanical energy converter at the lowest possible temperatures, since electrical resistance increases with temperature and thus higher efficiency can be expected at lower temperatures. However, the efficiency of the excitation windings is of secondary importance in this braking device. On the contrary, the aim is to convert as much braking energy as possible, recuperated by the electric motor, into heat in the winding as soon as the primary energy storage device cannot be charged at all or not with the current braking power.

[0259] The high-temperature adhesive can be a ceramic-based adhesive designed for high temperatures. Examples of high-temperature adhesives include: Ceramacast 505 (TE-Klebetechnik), Ceramacast 51 (TE-Klebetechnik), Ceramabond 503 (TE-Klebetechnik), Ceramacoat 512 (TE-Klebetechnik), Ceramacoat 512-N (TE-Klebetechnik), Thermigrease TG 20105 (Dr. Dietrich Müller GmbH), Thermigrease TG 20033 (Dr. Dietrich Müller GmbH) and / or Omegabond 600 (OMEGA Engineering GmbH).

[0260] Fiberglass fabrics are textile structures made from fiber-reinforced plastics.

[0261] DLR-4348WO

[0262] 2025-12-17 Reference number

[0263] 10 Eddy current braking device

[0264] 12 Stator part

[0265] 13 yoke of the stator part 12

[0266] 14 axle

[0267] 16 Rotor part

[0268] 18 wave

[0269] 20 air gap

[0270] 21 Excitation coil, excitation coils

[0271] 22 Pathogen device

[0272] 23 Energy storage

[0273] 24 Energy storage device

[0274] 25 Excitation current

[0275] 26 first power electronics

[0276] 28 first actuator

[0277] 30 force

[0278] 32 second actuator

[0279] 34 Force

[0280] 36 Spring assembly

[0281] 38 magnetic attraction

[0282] 40 Fluid channel

[0283] 42 vehicles

[0284] 44 wheel

[0285] 45 Axle between two wheels 44

[0286] 46 electric machine, motor

[0287] 48 electrical machine, generator

[0288] 50 Power Electronics

[0289] 52 gearboxes

[0290] 54 Parking brake

[0291] 56 Accelerometer

[0292] 58 Coolant system

[0293] 60 parts of the coolant circuit, coolant pump

[0294] 62 Brake pedal

[0295] 63 Coolant circuit valve

[0296] DLR-4348WO

[0297] 2025-12-17 64 first actuator element

[0298] 65 second actuator element

[0299] 66 first piston

[0300] 68 Fluid

[0301] 70 second piston

[0302] 72 Actuator

[0303] 74 first mechanical element

[0304] 76 Membran

[0305] 78 second mechanical element

[0306] 80 line

[0307] 82 second mechanical element

[0308] 84 direct connections

[0309] 86 rigid component

[0310] 88 connection

[0311] 90° toggle joint

[0312] 92 straight element

[0313] 94 hinge element

[0314] 96 Connecting element to piston 66

[0315] 98 fixed element

[0316] 99 Guide element

[0317] 100 connections

[0318] 102 Return spring

[0319] 104 Curved Bodies

[0320] 106 Electric motor

[0321] 108 Gear spindle

[0322] 110 threads

[0323] 112 Threaded nut

[0324] 114 Lifting magnet

[0325] 118 Arrow describing currents

[0326] 120 braking torque

[0327] 122 braking torque

[0328] 200 brake device

[0329] 300 computer systems

[0330] 310 Power Electronics

[0331] 315 Power semiconductors

[0332] DLR-4348WO

[0333] 2025-12-17 320 Power Electronics

[0334] 325 Power semiconductors

[0335] 330 Power Electronics

[0336] 335 Power semiconductors

[0337] 340 Power Electronics

[0338] 345 Power semiconductors

[0339] 350 Power Electronics

[0340] 355 Power semiconductors

[0341] 400 procedures

[0342] S410 process step

[0343] S420 process step

[0344] S430 process step

[0345] S440 process step

[0346] S450 process step

[0347] S460 process step

[0348] S470 process step

[0349] S480 process step

[0350] S490 process step

[0351] 500 procedures

[0352] S510 Procedure Step

[0353] S520 Procedure Step

[0354] S530 Procedure Step

[0355] 600 procedures

[0356] S610 Procedure Step

[0357] S620 Procedure Step

[0358] 710 Eddy current braking device

[0359] 712 Stator part of the eddy current braking device 710

[0360] 716 Rotor part of the eddy current braking device 710

[0361] 718 Shaft of the eddy current braking device 710

[0362] 740 Cooling circuit of the eddy current braking device 710

[0363] 742 Admission

[0364] 744 Outlet

[0365] 800 procedures with process steps S810 to S830

[0366] 900 procedures with process steps S010 to S930

[0367] DLR-4348WO

[0368] 2025-12-17

Claims

Claims 1. Braking device (200) for generating a total braking torque (120, 122) for a vehicle (42), comprising at least: an eddy current braking device (10), an energy storage device (24), and at least one electric machine (46, 48) electrically connected to the energy storage device (24), wherein the eddy current braking device (10) comprises a stator part (12), a rotor part (16) rotatably arranged relative to the stator part (12) about an axis of rotation (14), with a shaft (18) arranged in the axis of rotation (14), and an actuator device (10, 28, 32), wherein the rotor part (16) and the stator part (12) are spaced apart from each other by an air gap (20), wherein the stator part (12) comprises an excitation device (22) configured to generate a primary magnetic field, wherein an induction device is provided for inducing eddy currents are formed by a magnetic field, resulting in a first braking torque (120,122) is generated, wherein the actuator device (10, 28, 32) is configured to generate a force (30, 34) by means of which the rotor part (16) and the stator part (12) can be displaced relative to each other, thereby generating contact between the stator part (12) and the rotor part (16) and generating a second braking torque (120, 122), wherein the eddy current braking device (10) and / or the at least one electric machine (46, 48) are coupled at least temporarily to at least one wheel (44) of the vehicle (42).

2. Braking device (200) according to claim 1, wherein the actuator device (10, 28, 32) and the excitation device (22) are electrically connected to the electric machine (46, 48) and / or to the energy storage device (24) and / or are connected to an energy storage device (23). DLR-4348WO 2025-12-17 3. Braking device (200) according to claim 1 or 2, wherein the required electrical energy for the actuator device (10, 28, 32) can be generated in the electric machine (46, 48) and / or can be taken from the energy storage device (24) and / or from the energy storage device (23).

4. Braking device (200) according to one of the preceding claims, wherein the electric machine (46, 48) and / or the eddy current braking device (10) are coupled directly or via a transmission (110) at least temporarily to the at least one wheel (44).

5. Braking device (200) according to one of the preceding claims, wherein the energy storage device (24) has at least one, in particular several, energy storage units.

6. Braking device (200) according to one of the preceding claims, wherein at least one power electronics (26, 50, 310, 320, 330) is provided which is electrically connected to the energy storage device (24) and / or the energy storage (23) and / or the electric machine (46, 48).

7. Braking device (200) according to claim 6, wherein at least one of the energy storage units of the energy storage device (24) and / or the energy storage device (23) can be charged by the electric machine (46, 48) by means of the at least one power electronics (26, 50, 310, 320, 330).

8. Braking device (200) according to one of the preceding claims, wherein the excitation device (22) comprises excitation coils (21), wherein the excitation device (22) comprises or is made of aluminium or an aluminium alloy.

9. Braking device (200) according to one of the preceding claims, wherein the excitation coils (21) have a coil core (124) and a winding (126), wherein the windings (126) have a copper or aluminum strip and a high-temperature insulating material, in particular a glass fiber fabric, is arranged between adjacent turns of the winding (126) made of copper or aluminum strip. DLR-4348WO 2025-12-17 10. Brake device (200) according to claim 9, wherein the copper and / or aluminium tape and the high-temperature insulating material, in particular the fiberglass fabric, are joined by means of a high-temperature adhesive, in particular a ceramic adhesive.

11. Braking device (200) according to one of the preceding claims, wherein the actuator device (10, 28, 32) is an electrical or an electromagnetic or a mechanical actuator device (10, 28, 32) or a combination thereof.

12. Braking device (200) according to one of the preceding claims, wherein the eddy current braking device (10) has a cooling device (58) with a fluid (68) and is coolable by means of the fluid (68).

13. Braking device (200) according to one of the preceding claims, wherein the actuator device (10) comprises or is the stator part (12) and the rotor part (16), wherein the exerted force (38) is the magnetic attraction force between the stator part (12) and the rotor part (16).

14. Brake device (200) according to one of the preceding claims, wherein the actuator device (28, 32) has a hydrodynamic component, in particular a piston (66), and / or a mechanical component (86, 90, 102, 104), wherein the force (30, 34) can be transmitted directly or via the mechanical component (86, 90, 102, 104) to the rotor part (16) or the stator part (12) and in this way the displacement between stator part (12) and rotor part (16) can be generated.

15. Braking device (200) according to one of the preceding claims, wherein the excitation device (22) can be actively cooled by means of the fluid (68).

16. Brake device (200) according to one of the preceding claims, wherein the fluid (68) is used both in the cooling device (58) and in the hydrostatic component, in particular the piston (66). DLR-4348WO 2025-12-17 17. Brake device (200) according to one of the preceding claims, wherein the cooling device (58) comprises a coolant pump (60) and an electrically actuated valve (63), wherein the coolant pump (60) is used to generate pressure and the electrically actuated valve (63) is at least partially closed.

18. Vehicle (42), wherein the vehicle (42) has a braking device (200) according to any one of claims 1 to 17 with at least one eddy current braking device (10).

19. Vehicle according to claim 18, wherein the vehicle (42) has an on-board computer (300) and at least one acceleration sensor (56) for detecting at least one longitudinal acceleration of the vehicle (42).

20. Vehicle according to claim 18 or 19, wherein the eddy current braking device (10) comprises at least one stator part (12), a rotor part (16) rotatably arranged relative to the stator part (12) about an axis of rotation (14), with a shaft (18) arranged in the axis of rotation (14), and an actuator device (10, 28, 32), wherein the rotor part (16) and the stator part (12) are arranged concentrically to one another with an air gap (20) between them, wherein the stator part (12) comprises an excitation device (22) configured to generate a primary magnetic field, wherein an induction device is provided which is configured to induce eddy currents by a magnetic field, thereby generating a first braking torque (120, 122), wherein the actuator device (10, 28, 32) is configured to exert a force (30, 34) generate by means of which the rotor part (16) and the stator part (12) can be displaced relative to each other,whereby contact can be generated between the stator part (12) and the rotor part (16) and a second braking torque (120, 122) can be generated, wherein the eddy current braking device (10) and / or the electric machine (46, 48) are coupled at least temporarily with at least one wheel (44) of the vehicle (42).

21. Vehicle according to claim 18, 19 or 20, wherein a brake pedal (62) is provided by means of which a brake pressure can be generated. DLR-4348WO 2025-12-17 22. Vehicle according to one of claims 18 to 21, wherein the on-board computer (300) is configured to determine the current value of the acceleration from the brake pedal position or the brake pressure or a pedal force of the brake pedal (62) and / or to send the value of the current speed as a signal to the power electronics (26, 310, 320, 330) of the brake device (200).

23. Vehicle according to one of claims 18 to 22, wherein a parking brake (54) is provided.

24. Use of a braking device (200) according to one of claims 1 to 17 in a vehicle (42) according to one of claims 18 to 23, wherein the vehicle (42) is equipped for autonomous driving.

25. Method (400) for generating a total braking torque (120, 122) in a vehicle (42) according to claims 18 to 23, wherein the total braking torque (120, 122) is composed of a braking torque (120) of an eddy current braking device (10) and the braking torque (122) of an electric machine of the vehicle (42).

26. The method of claim 25, comprising the following steps: Determining the required total braking torque (120, 122), Determining a maximum braking torque (122) of the electric machine, in particular the motor of the vehicle (42), Determining the required braking torque (120) of the eddy current braking device (10) and of the generator (48), Data transmission of the determined braking torque (120, 122) of the eddy current braking device (10) and of the motor to the respective computer of the power electronics, Determining the required excitation current for the excitation device (22) of the eddy current braking device (10) and the required current for the actuator (28, 32), Determining a required electrical signal to set the power semiconductors of the power electronics (26, 50, 310, 320, 330), Generating the determined electrical signal and forwarding it to at least one power electronics unit (26, 50, 310, 320, 330). DLR-4348WO 2025-12-17 27. Method according to claim 25 or 26, wherein the determined electrical signal is forwarded to a power semiconductor and transmitted to the eddy current braking device (10) by means of the power electronics (26, 310, 320, 330) and / or power electronics (340).

28. A method according to any one of claims 25 to 27, wherein the electrical signal comprises one or more electrical signals which, at a given time, switch the power semiconductors on or off based on a target and actual value of a current, in particular a It is a pulse width modulation signal. DLR-4348WO 2025-12-17

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