Multi-layer braking resistor device for a vehicle

Description

[0001] The invention relates to a braking resistor device for a vehicle, a vehicle with such a braking resistor device and a method for operating the braking resistor device.

[0002] Braking resistors are used in vehicles to convert electrical energy recovered during braking into thermal energy. The maximum braking power is therefore limited by the braking resistors. The thermal energy generated during braking must be removed from the braking resistors. This thermal energy can be removed both actively and passively. Active cooling of the braking resistors requires additional components, such as a fan or additional heat exchangers, which reduce the energy efficiency of a braking system with braking resistors. Therefore, passively cooled braking resistors, for example, those cooled by airflow, are preferred. Document WO 2020 / 083620 A1 discloses a braking resistor device that is cooled by airflow.This braking resistor device comprises several braking resistor elements arranged parallel to one another in a single plane. This single-layer arrangement of braking resistor elements is characterized by a low overall height. However, in the case of the single-layer arrangement of braking resistor elements, the braking power of the braking resistor elements is linearly proportional to the floor space required for the arrangement of the braking resistor elements. This results in a large floor space requirement for the braking resistor elements to provide a high level of braking power.

[0003] US Pat. No. 3,624,581 A discloses an electrical resistor, particularly for a dynamic braking system of a locomotive, comprising a plurality of elongated resistance elements arranged in a housing and subjected to forced ventilation. KR 2011 0003626 U discloses a braking resistor with a housing made of aluminum material, insulation, and electrical connections. DE 10 2017 207274 B3 discloses a vehicle with an electrodynamic braking device having at least one braking resistor, wherein the braking resistor forms a permanently enclosed section of a vehicle shell around which airflow flows.

[0004] The invention is based on the object of providing a compact and energy-efficient braking resistor device.

[0005] This object is achieved by a braking resistor device having the features of independent patent claim 1.

[0006] Furthermore, the invention is based on the object of specifying a method for operating the braking resistor device.

[0007] This object is achieved by a method having the features of independent patent claim 12.

[0008] Advantageous further developments of the present invention can be found in the dependent patent claims.

[0009] The braking resistor device according to the invention for a vehicle has a plurality of braking resistor elements. These plurality of braking resistor elements each have a tubular, heat-conducting casing. A heat-conducting and electrically insulating material is arranged in said casing. An electrical conductor is embedded in the heat-conducting and electrically insulating material over a large part of the longitudinal extent of the casing. The plurality of braking resistor elements are arranged in a stack arrangement having several layers. These several layers are each formed from braking resistor elements arranged essentially parallel to one another. Furthermore, the described stack arrangement is configured to be passively cooled.

[0010] In the present context, a large part of a longitudinal extension of the casing is understood to mean a distance of at least 50% of a total longitudinal extension of the casing along a longitudinal extension direction of an associated braking resistor element.

[0011] Passive cooling refers to the dissipation of braking energy converted from electrical energy into thermal energy by braking resistor elements by means of airflow, convection, thermal radiation, and / or meteorologically induced air movement. The stacking direction of the stack arrangement can be transverse or, preferably, substantially perpendicular to a longitudinal direction of the braking resistor elements of the stack arrangement.

[0012] Thanks to the thermal capacity of the heat-conducting, electrically insulating material, the thermal energy that briefly occurs during braking can be passively dissipated continuously during driving. The rapid removal of the heat generated during braking, which was previously achieved either by means of braking resistor elements with the largest possible outer surfaces or by active heat removal, can be dispensed with. This makes it possible to keep the surface area of ​​the casing of the braking resistor element small. The stacked arrangement allows the ratio between the braking power of the braking resistor device and the base area covered by the braking resistor elements of the braking resistor device to be significantly increased.

[0013] According to the invention, the braking resistor elements of the stacked arrangement are arranged at a distance from one another such that the stacked arrangement can be permeated by airflow. The airflow can flow from an uppermost layer of the stacked arrangement to a lowermost layer of the stacked arrangement. This allows the multiple layers of braking resistor elements to be reliably surrounded and cooled by airflow.

[0014] Preferably, an intended flow direction of the airflow through the stack arrangement is substantially parallel to a longitudinal extension direction of the braking resistor elements, in particular viewed in a plane perpendicular to the stack direction of the stack arrangement.

[0015] According to the invention, the multiple layers are each formed from braking resistor elements arranged substantially parallel to one another in a plane extending substantially perpendicular to the stacking direction. This enables efficient utilization of the available installation space. According to the invention, the braking resistor elements of different layers of the multiple layers are arranged in alignment relative to one another in a stacking direction.

[0016] According to the invention, a clear distance between directly adjacent braking resistor elements of a first layer of the plurality of layers is at least twice as large, preferably at least three times as large, as a clear distance between the braking resistor elements of the first layer and the braking resistor elements of a further layer of the plurality of layers arranged directly adjacent to the first layer. In this way, a flow resistance of the braking resistor device can be reduced. The energy efficiency of the braking resistor device can thus be increased. The aforementioned first layer of the plurality of layers can be any layer of the plurality of layers and is not limited to an uppermost layer and / or a lowermost layer of the plurality of layers.

[0017] In a further advantageous embodiment, the clear distance between immediately adjacent braking resistor elements of a layer of the multiple layers is at least 1.5 times the value of the greatest extension of one of the immediately adjacent braking resistor elements. The said greatest extension of the braking resistor element is measured in a plane substantially perpendicular to the longitudinal direction of the braking resistor element. With the previously specified clear distance, a stack arrangement with low flow resistance could be realized in practice.

[0018] In an advantageous variant of the aforementioned embodiment, a further clear distance between at least some of the braking resistor elements of a first layer of the plurality of layers and braking resistor elements arranged directly adjacent to these braking resistor elements of a further layer arranged directly adjacent to the first layer has at least 0.5 times the value of the aforementioned greatest extension of one of the immediately adjacent braking resistor elements. In this way, a compact stack arrangement with low-resistance flow through it could be realized in practice.

[0019] An advantageous development provides that the braking resistor elements of the stacked arrangement are spaced apart by means of floating bearings, which have streamlined impact surfaces. Impact surfaces are defined as surfaces of the floating bearing that have a surface normal with a directional component that is directed counter to a designated flow direction of the airflow. This allows for a simple spacing between adjacent braking resistor elements to be achieved with low flow resistance.

[0020] In an advantageous embodiment, the floating bearings have rounded or chamfered impact surfaces. This allows for the cost-effective production of flow-optimized floating bearings.

[0021] In a further advantageous development, it is proposed that at least one fluid guide element be provided, by means of which a relative airflow can be directed into the stack arrangement for cooling the multi-layered braking resistor elements. With the aid of the at least one fluid guide element, a low-drag inflow and / or outflow of the relative airflow into the stack arrangement for cooling the braking resistor elements can be realized. A relative airflow can thus be directed between the multiple layers of braking resistor elements of the stack arrangement in a flow-optimized manner.

[0022] In an advantageous embodiment of the aforementioned development, the at least one fluid conducting element is designed, at least in sections, as a ramp. This enables cost-effective production of a fluid conducting element. Furthermore, it is proposed that the ramp be designed, at least in sections, as an inclined plane. This inclined plane is inclined by an angle from a value range of 10° to 25°, preferably from a value range of 19° to 23°, and particularly preferably substantially 21°, to the longitudinal direction of the braking resistor elements of the stack arrangement. In this way, a particularly energy-efficient introduction and / or discharge of the airstream flow has already been achieved in practice. In an alternative embodiment, it is conceivable that the inclined plane is inclined by an angle from a value range of 10° to 17° to the longitudinal direction of the braking resistor elements of the stack arrangement.

[0023] In a further advantageous embodiment of the ramp, a surface of the ramp can be provided with a profile according to a harmonic function in the mathematical sense. Particularly preferably, the ramp has curves in its transition areas. In this way, the fluid conduction properties of the at least one fluid conduction element can be easily optimized.

[0024] In another advantageous embodiment, the braking resistor elements of the stack arrangement each penetrate the at least one fluid guide element. This enables a space-efficient arrangement of the braking resistor elements in combination with a reduction in the flow resistance of the braking resistor device. For example, significant flow resistances, such as impact surfaces of the braking resistor elements with high flow resistance, can be arranged outside of a relative airflow. Preferably, the at least one fluid guide element is arranged in a longitudinal end region of the braking resistor device. The required overlap of the braking resistor elements by the at least one fluid guide element can be minimized.

[0025] In a further advantageous embodiment of the braking resistor device, it is proposed that dissipation paths of the braking resistor elements of the stack arrangement are arranged in a space delimited on one side. This space delimited on one side is delimited by a side of the at least one fluid conducting element against which the airstream flows. A dissipation path is to be understood as at least a section of a braking resistor element along its longitudinal direction, which section has increased dissipation relative to an electrical supply line of the braking resistor element. Typically, the electrical conductor is embedded in the heat-conducting, electrically insulating material along the dissipation path. This electrical conductor has reduced electrical conductivity compared to an electrical supply line to the braking resistor element.Along the dissipation path, electrical energy can be converted into thermal energy as efficiently as possible. Using the aforementioned arrangement, cooling of the dissipation paths along their entire extent can be easily achieved. At least one dissipation path extends along the longitudinal direction of each of the braking resistor elements. The dissipation path is preferably continuous. Particularly preferably, the dissipation path of one of the braking resistor elements has a continuous total length within a value range of 2 m to 10 m. In practice, a long, continuous dissipation path has proven to be more advantageous than several shorter dissipation paths.

[0026] In another advantageous embodiment of the aforementioned development, at least one partition wall is arranged between a rear side of the fluid conducting element, which faces away from a front side of the fluid conducting element intended for fluid conduction, and an electrical connection region of the braking resistor elements. By means of the at least one partition wall, an electrical connection region of the braking resistor elements can be thermally shielded. In other words, starting from an electrical connection region of the braking resistor elements of the stack arrangement, at least one partition wall is arranged in front of the at least one fluid conducting element. In this way, electrical connections of the braking resistor elements can be easily protected from thermal energy, in particular from heat build-up. In this way, the penetration of a heated airflow into the electrical connection region of the braking resistor elements can be prevented.

[0027] In an advantageous development, it is proposed that the dissipation paths of the braking resistor elements of a first of the multiple layers and the dissipation paths of the braking resistor elements of a further of the multiple layers be of different lengths. By adapting the dissipation paths to a path of the at least one fluid guide element and / or an intended path of the airflow, braking performance can be optimized.

[0028] In a further advantageous development, it is provided that a resistance of the electrical conductors embedded in the braking resistor elements of a first of the multiple layers and a resistance of the electrical conductors embedded in the braking resistor elements of a further one of the multiple layers are different. By using resistors of different sizes, a correspondingly different conversion of electrical energy into thermal energy can be realized. This makes it possible to convert larger amounts of energy in regions within the stack arrangement in which there is a higher potential for the transport of this thermal energy by the airflow. This can reduce temperature differences within the stack arrangement.Preferably, electrical conductors are embedded in the braking resistor elements of the uppermost layer of the plurality of layers, by means of which a larger amount of electrical energy can be converted into thermal energy compared to the electrical conductors embedded in the braking resistor elements of the remaining layers of the plurality of layers. Compared to the other layers of the plurality of layers, a larger amount of thermal energy can thus be generated in the uppermost layer during a braking operation. As a result, the better heat dissipation of the uppermost layer compared to the other layers can be utilized to enable improved temperature distribution within the stack arrangement. Furthermore, in this way, a ratio of the power of the braking resistor device to a surface area of ​​the braking resistor elements required to dissipate the converted thermal energy can be optimized.In addition, the efficiency of the braking resistor device can be improved.

[0029] In another advantageous development, the stack arrangement is arranged in a housing, in particular in a trough-shaped housing. The housing has an opening on one side, which extends over at least 80% of the length of one of the dissipation paths of the braking resistor elements of the stack arrangement, preferably over the entire length of a longest dissipation path of the dissipation paths of the braking resistor elements of the stack arrangement. In this way, a low-drag guidance of the airflow through the stack arrangement can be achieved.

[0030] In an advantageous embodiment of the further development, a maximum stack height of the stack arrangement is less than or equal to a maximum housing height of the housing. This allows the flow resistance of the braking resistor device to be further reduced.

[0031] In a further advantageous embodiment of the refinement, the housing is bordered on at least two sides by a fluid guide element. This enables the introduction and discharge of the airflow through the multiple layers of the stack arrangement by means of the fluid guide elements with low flow resistance. Cooling of the braking resistor device can thus be achieved regardless of the direction of travel.

[0032] The stack arrangement is preferably arranged in the housing such that each of the braking resistor elements of the stack arrangement penetrates the housing at two positions along the longitudinal direction of the braking resistor elements. This makes it possible to arrange flow resistances present on both sides of the braking resistor elements, such as the aforementioned baffles, outside the airflow. Furthermore, at least two partition walls are preferably provided, which are each arranged outside the housing in one of the two longitudinal end regions of the braking resistor elements of the stack arrangement. Thermal shielding of the electrical connection regions of the braking resistor elements can thus be achieved independently of the flow direction of the airflow.

[0033] In another advantageous embodiment of the aforementioned refinement, the dissipation paths of the braking resistor elements of the stacked arrangement are arranged exclusively within the housing. This allows cooling of the dissipation paths along their entire length by means of the airflow.

[0034] Preferably, the different lengths of the dissipation paths of the braking resistor elements of the multiple layers of the stack arrangement are at least partially adapted to a maximum longitudinal extension of the housing. This enables optimization of the braking performance.

[0035] In an advantageous embodiment, the braking resistor elements of the stacked arrangement are arranged relative to the housing such that they are spaced apart in a direction substantially perpendicular to the longitudinal extension direction of the braking resistor elements, largely by a clearance of at least 1.5 times the greatest extension of the respective braking resistor elements. In this way, a flow of air can also cool braking resistor elements arranged in peripheral regions, in particular their dissipation paths. Heat buildup in peripheral regions can thus be avoided.

[0036] Advantageously, a vehicle is equipped with the braking resistor device according to the invention. The vehicle has a vehicle shell. A recess is formed in the vehicle shell. The braking resistor device is recessed into the recess of the vehicle shell in such a way that an uppermost layer of the multiple layers of the stacked arrangement of the braking resistor device is arranged flush with or below the vehicle shell surrounding the recess. The at least one fluid conducting element can project beyond a surrounding vehicle shell, at least in sections. In this way, a vehicle with a compact braking resistor device can be provided. In particular, a deterioration of the overall flow resistance of the vehicle can be prevented in this way.

[0037] In an advantageous development of the vehicle, the braking resistor device is arranged on a roof of the vehicle, recessed into the vehicle body. This enables a reliable arrangement of the braking resistor device.

[0038] By means of the method according to the invention, the braking resistor device according to the invention or the vehicle with such a braking resistor device can be operated.

[0039] The method according to the invention provides that the braking resistor elements arranged in a stacked multilayer configuration are passively cooled by a relative airflow. This enables energy-efficient cooling of the braking resistor device, which avoids the need for additional energy consumption for cooling the braking resistor device, for example, by means of active cooling devices.

[0040] The properties, features, and advantages of the invention described above, as well as the manner in which they are achieved, are explained in more detail in conjunction with the figures in the following description of an exemplary embodiment of the invention. Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention. The exemplary embodiment serves to illustrate the invention and does not limit the invention to the combinations of features specified therein, including with regard to functional features. Furthermore, all specified features can be considered in isolation and combined as appropriate with the features of any claim.

[0041] They show: FIG 1 shows a schematic representation of a vehicle with an example of the braking resistor device according to the invention and an illustration of an example of the operation of the braking resistor device according to the invention; FIG 2 shows a schematic representation of a cross-section in a plane perpendicular to a longitudinal extension direction of the braking resistor elements of the exemplary embodiment of the braking resistor device; FIG 3 shows a detailed view of a floating bearing of the exemplary embodiment of the braking resistor device in a schematic representation; FIG 4 shows an end region of the exemplary embodiment of the braking resistor device in a schematic representation.

[0042] FIG 1 shows a schematic representation of an embodiment of the braking resistor device 10 according to the invention in a vehicle 12. Furthermore, FIG 1 an inventive method for operating the braking resistor device 10.

[0043] The vehicle 12 is designed as a rail-bound, multi-unit vehicle and has a vehicle shell 54. A recess 56 is provided in the vehicle shell 54. The recess 56 is arranged on the roof of the vehicle 12 in the vehicle shell 54. The braking resistor device 10 is recessed into this recess 56. This braking resistor device 10 is passively cooled by a relative airflow 38.

[0044] The braking resistor device 10 has a stack arrangement 14 with four layers 18 of braking resistor elements 20 arranged one above the other in a stacking direction 16. Each of the four layers 18 is formed from a plurality of braking resistor elements 20 arranged substantially parallel to one another in a plane. Each of the four planes in which the braking resistor elements 20 are arranged extends substantially perpendicular to the stacking direction 16.

[0045] In FIG 2 a cross section through the stack arrangement 14 is shown in a plane which extends substantially perpendicular to a longitudinal extension direction 30 of the braking resistor elements 20.

[0046] In the present exemplary embodiment, the structure of the braking resistor elements 20 each corresponds to a previously known tubular heater. Each of the braking resistor elements 20 has a tubular casing 62 with a round cross-section. Alternatively, a polygonal cross-section of the casing is also conceivable. The casing 62 consists of a high-temperature-resistant metal or a high-temperature-resistant metal alloy, in particular stainless steel or a nickel-based alloy. A thermally conductive and electrically insulating material 64 is provided in sections of the casing 62. In the present exemplary embodiment, this thermally conductive and electrically insulating material 64 is magnesium oxide. An electrical conductor 66 is embedded in the thermally conductive and electrically insulating material 64.This electrical conductor 66 has increased dissipation compared to an electrical supply line to the braking resistor element 20. In this way, a dissipation path 42 is created along the longitudinal direction 30 of the tubular heater and thus of the braking resistor element 20. Along the dissipation path 42, electrical energy can be converted into thermal energy. By means of the aforementioned material 64, it is possible to store large amounts of thermal energy that occur briefly and then continuously release it to an environment. This makes it possible to cool the stack arrangement 14 solely by means of the airflow 38, despite large amounts of thermal energy that occur briefly, in particular. In the present exemplary embodiment, each dissipation path 42 of the dissipation paths 42 has a continuous length of at least six meters.

[0047] The braking resistor elements 20 of the stack arrangement 14 are arranged at a distance from one another in such a way that a relative wind can flow through the stack arrangement 14. The relative wind can flow from an uppermost layer 22 of the stack arrangement 14 to a lowermost layer 24 of the stack arrangement 14. In this way, the relative wind can flow around and cool all of the braking resistor elements 20 of the four layers 18. Electrical energy converted at the braking resistor elements 20 can thus be transported away as thermal energy with the relative wind. In order to achieve the lowest possible flow resistance, a clear distance 26 between immediately adjacent braking resistor elements 20 of each of the four layers 18 has a value 1.5 times the tube diameter of the braking resistor elements 20.In addition, a further clear distance 28 between braking resistor elements 20 of one layer of the four layers 18 and braking resistor elements 20 arranged directly adjacent to these braking resistor elements 20 of a layer of the four layers 18 arranged directly adjacent to this layer is at least 0.5 times the value of the tube diameter of the braking resistor elements 20. In this way, the clear distance 26 between directly adjacent braking resistor elements 20 of one of the four layers 18 is three times as large as the further clear distance 28 between the braking resistor elements 20 of one of the four layers and the braking resistor elements 20 of a further layer of the four layers 18 arranged directly adjacent to this layer.

[0048] In order to space the braking resistor elements 20 apart from one another as described above, floating bearings 32 are provided in the present exemplary embodiment. These floating bearings 32 can each have a plurality of floating bearing retaining tabs 58, which are fastened to a floating bearing support section 60. The floating bearing retaining tabs 58 are configured to permit a sliding movement of the braking resistor elements 20 along a longitudinal extension direction 30 of the braking resistor elements 20 relative to the floating bearing retaining tabs 58. Furthermore, insulation panels (not shown in detail) are provided, by means of which heat conduction from the braking resistor elements 20 through the floating bearings 32 into a supporting structure is prevented.

[0049] FIG 3 shows an embodiment of the previously described floating bearing 32 with streamlined impact surfaces 34 in a schematic representation. A section of the stacking arrangement 14 is shown here. Both impact surfaces 34 of the floating bearing retaining tabs 58 and impact surfaces 34 of the floating bearing support section 60 are chamfered. Preferably, a length of a chamfered surface of the floating bearing support section 60, measured in a plane substantially perpendicular to the stacking direction 16, is approximately 4.5 times a thickness of the floating bearing support section 60, measured in this plane. In addition, the impact surfaces 34 are rounded in sections. Flow resistance of the floating bearings 32 can be minimized in this way.

[0050] FIG 4 shows a schematic representation of a section of the FIG 1 shown braking resistor device 10 in a plane substantially perpendicular to the stacking direction 16 and to the longitudinal extension direction 30 of the braking resistor elements 20. The position of the FIG 4 shown section of the braking resistor device 10 is shown in FIG 1 marked with the Roman numeral "IV" and corresponds to one of two opposite end regions of the braking resistor device 10. These opposite end regions are mirror images of each other. For the sake of clarity, only one of the two end regions is shown, representing both end regions.

[0051] In the present embodiment, the stack arrangement 14 is arranged in a housing 52. The housing 52 is trough-shaped and has an opening on its upper side. The opening extends in the longitudinal direction 30 of the braking resistor elements 20 over the entire length of the dissipation paths 42 of the braking resistor elements 20. In the present embodiment, the housing 52, as in FIG 1shown, formed integrally with the recess 56 of the vehicle shell 54. In the present exemplary embodiment, a maximum stack height of the stack arrangement 14 is smaller than a maximum housing height of the housing 52. In this way, the braking resistor device 10 can be arranged recessed in the recess 56 such that the uppermost layer 22 of the four layers 18 is arranged below a vehicle shell 54 surrounding the recess 56. Furthermore, in the present exemplary embodiment, the housing 52 and thus the recess 56 are delimited on two sides by a fluid guide element 36 each. The fluid guide elements 36 are designed to introduce the airflow 38 into the stack arrangement 14 and to guide the airflow 38 out of the stack arrangement 14 in order to cool the multi-layered braking resistor elements 20. The two fluid guide elements 36 are each arranged in one of the above-mentioned end regions of the braking resistor device 10.Each of the two fluid guide elements 36 is partially configured as a ramp. This ramp has an inclined plane, which in the present exemplary embodiment is inclined at an angle 40 of substantially 21° to the longitudinal direction 30 of the braking resistor elements 20. Furthermore, the fluid guide elements 36 each have curves in their transition regions to the vehicle shell 54. In the present exemplary embodiment, this curve projects beyond a height of a directly adjacent region of the vehicle shell 54. In this way, the braking resistor elements 20, arranged one above the other in multilayer stacked arrangement 14, are passively cooled with low flow resistance by means of the airstream 38.

[0052] The braking resistor elements 20 of the stack arrangement 14 each penetrate the two fluid conducting elements 36. The dissipation paths 42 of the braking resistor elements 20, however, are arranged exclusively in a region of the housing 52 through which the airflow 38 flows and each end in front of a front side 44 of the fluid conducting elements 36 against which the airflow flows. In this way, the dissipation paths 42 of the braking resistor elements 20 are arranged exclusively in a space within the housing 52 delimited by the front sides 44 of the two fluid conducting elements 36 against which the airflow flows. The dissipation paths 42 of the braking resistor elements 20 of the uppermost layer 22 are longer than the dissipation paths 42 of the braking resistor elements 20 of the layers 18 arranged below the uppermost layer 22.In addition, electrical conductors 66 are embedded in the braking resistor elements 20 of the uppermost layer 22, which convert a greater amount of electrical energy into thermal energy compared to electrical conductors 66 embedded in one of the remaining braking resistor elements 20 of the remaining layers of the multiple layers 18. Better heat dissipation by the airflow 38 at the uppermost layer 22 compared to the remaining layers of the multiple layers 18 thus leads to a reduction in temperature variation within the stack arrangement 14. In the present exemplary embodiment, the dissipation paths 42 of the braking resistor elements 20 of the lowermost layer 24 are the shortest dissipation paths 42 compared to the dissipation paths 42 of the braking resistor elements 20 of the remaining layers. The dissipation paths 42 are adapted to the partially ramp-shaped course of the two fluid conducting elements 36.

[0053] Furthermore, the present exemplary embodiment provides partition walls 50, by means of which an electrical connection area 48 of the braking resistor elements 20 can be thermally shielded. Two partition walls 50 are arranged between the electrical connection area 48 and a rear side 46 of each of the two fluid conducting elements 36. Each of the two partition walls 50 has different inclinations relative to the longitudinal direction 30 of the braking resistor elements 20. In this way, it is easy to prevent large portions of a thermally charged airflow 38 from entering the electrical connection area 48 of the braking resistor elements 20.

[0054] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited to the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

1. Braking resistor device (10) for a vehicle (12) comprising - a plurality of braking resistor elements (20), each having a tubular, thermally conductive jacket (62); - wherein a thermally conductive and electrically insulating material (64) is arranged in the jacket (62); - wherein an electrical conductor (66) is embedded in the thermally conductive and electrically insulating material (64) over at least 50% of a total longitudinal extent of the jacket (62) along a longitudinal extent of an associated braking resistor element (20); - wherein the plurality of braking resistor elements (20) are arranged in a stack arrangement (14) with a plurality of layers (18); - wherein the plurality of layers (18) are each formed from braking resistor elements (20) which are arranged substantially parallel to each other in a plane which extends substantially perpendicularly with respect to the stack direction (16); - wherein the braking resistor elements (20) of different layers of the plurality of layers (18) are arranged so as to be flush relative to one another in the stack direction, - wherein the braking resistor elements (20) of the stack arrangement (14) are arranged spaced apart from each other in such a way that the stack arrangement (14) can be flowed through by an airflow, and the airflow can flow from an uppermost position (22) of the stack arrangement (14) to a bottommost position (24) of the stack arrangement (14), - wherein a clear distance (26) between immediately adjacently arranged braking resistor elements (20) of a first layer of the plurality of layers (18) is at least twice as large, preferably at least three times as large, as a further clear distance (28) between the braking resistor elements (20) of the first layer and the braking resistor elements (20) of a further layer of the plurality of layers (18) which is arranged directly adjacently to the first layer; and - wherein the stack arrangement (14) is configured to be passively cooled.

2. Braking resistor device according to Claim 1, characterized in that the clear distance (26) between directly adjacent braking resistor elements (20) of one layer of the plurality of layers (18) is at least 1.5 times a largest extent of one of the directly adjacently arranged braking resistor elements (20), measured in a plane extending substantially perpendicularly with respect to the longitudinal extent direction (30) of the braking resistor element (20).

3. Braking resistor device (10) according to either of the preceding claims, characterized in that the braking resistor elements (20) of the stack arrangement (14) are spaced from each other by means of floating bearings (32) which have streamlined deflector surfaces (34).

4. Braking resistor device (10) according to either of the preceding claims, characterized in that at least one fluid guiding element (36) is provided, by means of which a travel airflow (38) can be guided into the stack arrangement (14) for cooling the braking resistor elements (20) which are arranged in a plurality of layers.

5. Braking resistor device (10) according to Claim 4, characterized in that the at least one fluid guiding element (36) is formed at least in sections as a ramp, - the ramp is designed at least in sections as an oblique plane, and - the oblique plane is inclined by an angle (40) from a value range of 10° to 25°, preferably from a value range of 19° to 23° and particularly preferably of substantially 21° with respect to a longitudinal extent direction (30) of the braking resistor elements (20) of the stack arrangement (14).

6. Braking resistor device (10) according to Claim 4 or 5, characterized in that - the braking resistor elements (20) of the stack arrangement (14) each penetrate the at least one fluid guiding element (36), and - dissipation sections (42) of the braking resistor elements (20) of the stack arrangement (14) are arranged in a space which is delimited on one side and is delimited by a front side (44), onto which the airflow flows, of the at least one fluid guiding element (36).

7. Braking resistor device (10) according to Claim 6, characterized in that - at least one partition wall (50) is arranged between a rear side (46) of the fluid guiding element (36), which faces away from a front side (44) of the fluid guiding element (36) provided for the fluid guidance, and an electrical connection region (48) of the braking resistor elements (20), and - an electrical connection region (48) of the braking resistor elements (20) is thermally shieldable by means of the at least one partition wall (50).

8. Braking resistor device (10) according to either of the preceding claims, characterized in that the dissipation sections (42) of the braking resistor elements (20) of a first layer of the plurality of layers (18) and the dissipation sections (42) of the braking resistor elements (20) of a further layer of the plurality of layers (18) are formed with different lengths.

9. Braking resistor device (10) according to either of the preceding claims, characterized in that - the stack arrangement (14) is arranged in a housing (52), in particular in a tub-shaped housing which has an opening on one side which extends over at least 80% of a length of one of the dissipation sections (42) of the braking resistor elements (20) of the stack arrangement (14), preferably over an entire length of a longest dissipation section of the dissipation sections (42) of the braking resistor elements (20) of the stack arrangement (14), and - a maximum stack height of the stack arrangement (14) is less than or equal to a maximum housing height of the housing (52).

10. Braking resistor device (10) according to Claim 9, characterized in that the dissipation sections (42) of the braking resistor elements (20) of the stack arrangement (14) are arranged exclusively within the housing (52).

11. Vehicle (12) having a vehicle shell (54) and a braking resistor device (10) according to one of the preceding claims which is arranged recessed in a formed recess (56) of the vehicle shell (54) in such a way that an uppermost layer (22) of the plurality of layers (18) of a stack arrangement (14) of the braking resistor device (10) is arranged flush with or below the vehicle shell (54) surrounding the formed recess (56).

12. Method for operating the braking resistor device (10) according to one of Claims 1 to 10, wherein braking resistor elements (20) which are arranged in multiple layers above one another in a stack arrangement (14) are cooled by a travel airflow (38).