Brake device for vehicle, in particular eddy current brake

Abstract

The invention relates to a braking device (10) of a vehicle, in particular an eddy current brake (12) of a vehicle. The braking device (10) comprises a magnet element (24) and a braking element (18) which are configured symmetrically with respect to an axis of symmetry (16). The braking device (10) is implemented in a combined axial / radial configuration (40), wherein the stator (42) is surrounded by the rotor (60). The invention further relates to a method for using the brake device (10) in a vehicle.

Description

TECHNICAL FIELD

[0001] The invention relates to a brake device, in particular an eddy current brake, of a vehicle, wherein the brake device comprises magnet elements and brake elements which are configured symmetrically with respect to a symmetry axis. Furthermore, the invention relates to a use scenario of the brake device in a vehicle for passenger transport, a transport vehicle, a commercial vehicle, a two-wheeled vehicle, a three-wheeled vehicle or a multi-wheeled vehicle, a bus, a military vehicle, a truck-trailer or a rail vehicle. BACKGROUND

[0002] US 2920220 A relates to an eddy current brake, wherein pulses occur not only in the radial direction, but also simultaneously in the axial direction. According to this solution, an eddy current brake is proposed, wherein magnetic strips or magnet coils are provided in the stator and in the rotor. They are arranged in the stator and in the rotor at an angle with respect to each other, so that the magnetic field not only passes through the eddy current area in the radial direction, but also expands from the tooth starting point to the tooth top in the axial direction. Thereby, in addition to the pulses, a continuous spatial displacement of the magnetic field occurs. An eddy current brake is disclosed, wherein the inclined teeth of the rotor are arranged such that there is a gap between the end of one tooth and the start of the next tooth, which gap causes the eddy current to be displaced from the start to the end of the tooth in the radial direction and in the axial direction.

[0003] DE 1031411 B relates to an eddy current brake, wherein the force transmission from the engaged drive element onto the smooth, water-cooled, coil- equipped component is achieved by means of the eddy current through the magnetic field. Furthermore, the cylinder is thermally shrunk onto the stator stack, wherein the stator elements equipped with the coil arranged on the outside are configured as a drum at the outer circumference, and the stator elements arranged on the inside carry a directly cooled cylinder consisting of well-conducting metal as an outer cylinder, which can expand uniformly over the entire circumference.

[0004] AT 505585 A2 relates to a liquid-cooled eddy current brake for braking various types of axles or drive trains, which has a claw pole wheel driven by the axle as a magnetic field transmission- and force receiver unit, a stator sheet unit and a stator sheet induction ring, wherein one of the three components comprises the inductor component of the eddy current brake and the induction component of the eddy current brake and the force transmission component of the eddy current brake, wherein the induction component of the eddy current brake is arranged stationary or position-fixed and the force transmission component is arranged dynamically or rotationally.

[0005] In a drag brake, eddy currents are induced in the range of the applied magnetic field in a rotating, electrically conductive element. By the interaction of the magnetic field between the eddy currents and the applied magnetic field, a mechanical braking action is produced. The construction of the drag brake is realized either in a radial design or in an axial design. The required high braking torque determines a correspondingly large size of the brake disc, so that the brake disc is not thermally overloaded. In the case of too severe heating, the braking power can no longer be ensured. Furthermore, the brake disc cannot be operated in a liquid cooling medium in a mechanically rigidly coupled system, because otherwise a constant braking torque would be transmitted, which would consume power. SUMMARY

[0006] The invention relates to a brake device of a vehicle, in particular a drag brake of a vehicle, wherein the brake device comprises magnet elements and brake elements which are constructed symmetrically with respect to a symmetry axis. The brake device is embodied in a combined axial / radial design, wherein the stator surrounds the rotor.

[0007] By means of the brake device according to the invention, a very compact construction of the drag brake can be realized in an advantageous manner, which can be cooled by means of a cooling system which is fixedly arranged in the stator of the drag brake due to the compact construction.

[0008] In an advantageous refinement of the brake device according to the invention, the brake device is distinguished in that the rotor completely surrounds the stator. Due to the compact construction which can be realized thereby, the rotor which rotates with respect to the stator can also be efficiently cooled by means of a cooling system which is essentially constructed in the rigidly received stator, so that the thermal load of the brake device according to the invention can be significantly reduced.

[0009] In an advantageous refinement of the brake device according to the invention, the rotor comprises a first material which is mounted at its end side and a second material which forms its peripheral side. As first and second material, materials can be considered which have the necessary mechanical, thermal and electrical properties, such as, for example, gray cast iron.

[0010] In an advantageous refinement of the brake device according to the invention, the cavity between the rotor and the stator is minimized in terms of its volume. Thereby, in an advantageous manner, the possibility is derived that the rotor which surrounds the fixedly arranged stator through which a cooling medium flows can also be cooled or rather cooled down.

[0011] In an advantageous manner, in the brake device according to the invention, it is provided that the stator has a peripheral side at which the field winding or the permanent magnet which is arranged in a radial position is located. By means of the field winding or the permanent magnet, the section of the rotor which rotates at the peripheral side of the stator can be magnetized.

[0012] In a further advantageous design of the brake device according to the application it is provided that the stator has a first and a second end side, and that the field winding or the permanent magnet is arranged in axial position at the first and the second end side. Here too it is ensured that the region of the magnetized rotor rotates past at the first and the second end side of the stator. The combined radial and axial design of the stator and the permanent magnet or the field winding received in different radial or axial positions at the stator thus provides the possibility of generating the greatest degree of eddy current induction in the rotating component on the smallest construction space.

[0013] In an advantageous refinement of the brake device according to the application it is provided that the field winding in axial and radial position of the fixedly arranged stator corresponds to the first and the second material of the rotor encircling the stator.

[0014] In a further advantageous design of the brake device according to the application the stator axis of the stator forms an inflow side and an outflow side for a cooling medium flowing through the stator or the stator core. This design variant of the solution according to the application significantly simplifies the sealing or the line guidance for the cooling medium, since the cooling medium flows through a fixedly extending component and does not require a complex sealing as in a rotating component.

[0015] In an advantageous refinement of the brake device according to the application it is provided that the flow path of the cooling medium extends through the stator core of the stator such that it includes the first and the second end side and the peripheral side of the stator core. By this kind of guidance of the flow path through the stator core of the stator it is possible to achieve an optimum heat dissipation of the stator core or the field winding or the permanent magnet, wherein at the same time, due to the compact design, a heat dissipation of the rotor rotating around the stator core of the stator is also possible.

[0016] In a further advantageous design of the brake device according to the application the flow path of the cooling medium includes the stator core of the stator and the rotor. This can be achieved by a minimization of the inner chamber or cavity, so that the air gap or cavity remaining between the stator or the stator core and the inner side of the rotor rotating around it is minimal and facilitates heat dissipation.

[0017] In a further advantageous design of the brake device according to the application it is provided that the first and / or the second material of the rotor has a different electrical conductivity. As further distinguishing criteria, for example, the wall thickness, the wall thickness trend, the thermal conductivity and / or the magnetic permeability can be listed.

[0018] The application furthermore relates to the use of the brake device in a vehicle for passenger transport, a transport vehicle, a commercial vehicle, a two-wheeled vehicle, a three-wheeled vehicle or a multi-wheeled vehicle, a military vehicle, a bus, a truck-trailer or a rail vehicle.

[0019] Advantages of the application.

[0020] In an advantageous manner, it is possible by means of the axial design and the radial design of the brake device, in particular of the eddy current brake, according to the application to arrange the largest number of field windings or permanent magnets in the interior of the eddy current brake in the form of a stationary component at the stator core of the stator. In the case of a construction of the smallest possible air gap between the field windings or permanent magnets and the inner side of the rotor rotating around the stator core, the rotor rotates around the stator. In this way, on the one hand, a compact design is possible, and on the other hand, it is possible by means of the solution according to the application to achieve that the stationary component, in the present case the stator core of the stator, can be cooled by means of the rigidly extending stator shaft.

[0021] In an advantageous manner, cooling is achieved by means of a cooling medium flowing through the stator shaft on the entry side and on the exit side, the flow path of which extends through the stator core of the stator in such a way that, in particular, the peripheral side of the stator core and, preferably, the two end sides of the stator core which are rotationally symmetrical are passed through by the cooling medium flow and waste heat can be carried away. In the design according to the application of the eddy current brake as a combined axial design or radial design, it is furthermore possible to achieve that, in the case of a minimized cavity in the interior of the rotor, the rotor which is arranged at a minimum distance from the stator core can also be cooled by means of the flow through the stator core. This means that the cooling system which runs through the stator core of the stator also cools the rotor rotating around the stator core of the stator.

[0022] By means of the radial or axial design according to the application, it is possible not only to accommodate the largest number of field windings or permanent magnets in the cavity, but also to achieve cooling of the rotor rotating relative to the stationary component.

[0023] The rotor according to the application can be constructed from a first material with respect to its end sides and can be made of a second material with respect to its circumferentially extending peripheral side. The two materials of the rotor can be distinguished from one another, for example, by their electrical conductivity and further parameters. In principle, it is possible to use all materials which have the necessary mechanical, thermal or electrical properties, such as, for example, grey cast iron materials.

[0024] The brake device according to the application in the design of the eddy current brake configured in a highly compact configuration requires a small installation space. Here, the rigid stator shaft not only transports the cooling medium but also the excitation current to the individual excitation coils arranged in the radial or axial position. Furthermore, sealing is significantly easier in the rigid shaft, such as the fixedly arranged stator shaft of the stator core, than in the case of rotating components, such as the rotor rotating around the stator core.

[0025] The brake device according to the application provides maximum braking power in a relatively small and very compact installation space. A short-time high current density in the excitation coils can be achieved, since the stator is cooled by a liquid and ensures continuous removal of waste heat. Optimization of the braking characteristic curve can be achieved by the selection of the first and second materials, which is further supported by the structure of the rotor of the brake device according to the application. Furthermore, in the solution according to the application, a combination of the cooling circuit with other elements to be cooled in the vehicle can be achieved, so that one or more already existing cooling circuits can be used multiply. BRIEF DESCRIPTION OF DRAWINGS

[0026] Embodiments of the application are explained in more detail according to the drawings and the following description.

[0027] wherein:

[0028] Figure 1 a schematic view of the radial structure of the eddy current brake is shown,

[0029] Figure 2 a schematic view of the axial structure of the eddy current brake is shown,

[0030] Figure 3 a cross section of the brake device according to the application in the design of the eddy current brake in axial and radial configuration is shown,

[0031] Figure 4 a cross section of the stator shaft of the stator is shown, and

[0032] Figure 5 a schematic view of the flow path of the cooling medium on the inlet side and the outlet side when flowing through the stator core of the stator of the eddy current brake according to the application in the combined axial and radial configuration is shown. DETAILED DESCRIPTION

[0033] In the following description of embodiments of the application, identical or similar elements are denoted by the same reference signs, wherein a repeated description of these elements is dispensed with in individual cases. The drawings only schematically show the subject matter of the application.

[0034] Figure 1 A schematic representation of a brake device 10 is shown, which is configured as an eddy current brake 12. The brake device is configured in a radial configuration 14 and is embodied substantially symmetrically with respect to a symmetry axis 16, which extends in the drawing according to Figure 1 the vertical direction. The brake device 10 configured as an eddy current brake 12 in the radial configuration 14 comprises a brake element 18, which is configured as a brake drum 20. Furthermore, a magnet element 24 is provided, which is embodied as a magnetic pot 26 and receives a ring-shaped magnet 30, which is ring-shapedly placed into the magnetic pot.

[0035] Figure 2 In contrast thereto, an axial configuration 32 of a brake device 10 configured as an eddy current brake 12 is shown in a schematic representation.

[0036] Figure 2 It is shown that, in the brake device 10 configured as an eddy current brake 12 in the axial configuration 32, the brake element 18 is configured as a brake disc 22. The brake element is opposed to a magnetic disc 28, which serves as a magnet element 24 and is placed into a shorter configured magnetic pot 26. A minimum air gap is configured between the end sides of the brake disc 22 and the magnetic disc 28, which are directed towards one another.

[0037] From the drawing according to Figure 3 a schematic sectional view of a brake device 10 configured as an eddy current brake 12 in a combined axial / radial configuration 40 can be derived.

[0038] From the sectional view according to Figure 3 the stator 42 comprises a stator core 44. The stator core 44 is configured substantially symmetrically with respect to a symmetry axis of the stator axis 46. At the outer side of the stator core 44 of the stator 42, field coils 48 can be arranged or, alternatively, permanent magnets. From the drawing according to Figure 3 it is derived that, for example, at the peripheral side 58 of the stator core 44, that is to say along the circumference thereof, a plurality of field coils 48 can be received. These field coils are received in radial positions 52 along the peripheral side 58 of the stator core 44 according to the drawing in Figure 3 Furthermore, at the two end sides 54, 56 of the stator core 44, which are opposite one another, field coils 48 are present, which are arranged in axial positions 50. Instead of the mentioned field coils 48, permanent magnets can be arranged not only in the radial positions 52 at the peripheral side 58 but also in the axial positions 50 at the end sides 54, 56, which are opposite one another. As will be described further below, the stator core 44 of the stator 42 is traversed by a cooling medium.

[0039] In Figure 3The configuration shown in Fig. 1 is derivable in the brake device 10 in the combined axial / radial configuration form 40 of the eddy current brake 12, that the cavity 68 in the interior of the eddy current brake 12 is designed as a minimized inner cavity 66, that is to say designed with a minimum volume. This means that the spacing of the upper side of the field coil 48 is arranged with a minimum spacing to the inner side of the rotor 60 not only in its arrangement in the axial position 50 but also in the radial position 52.

[0040] The rotor 60 represents the rotating component of the eddy current brake 12 in the combined axial / radial configuration form 40 and comprehensively surrounds the stator core 44 of the stator 42 together with the field coil 48 or the permanent magnet received thereat. Thereby a most compact construction of the eddy current brake 12 in the combined axial / radial configuration form 40 according to the invention can be achieved with regard to the minimized inner cavity 66 of the cavity 68 between the stator 42 and the rotor 60. It is derivable that the rotor 60 is made of a second material 64 with regard to its peripheral side 100, whereas the first end side 96 and the second end side 98 opposite to each other with regard to the rotor 60 are made of a first material 62 mounted in the axial direction. The first material 62 and the second material 64 of which the rotor 60 is made can for example have different electrical conductivity. In addition to the different conductivity of the first material 62 and the second material 64 it is pointed out that further distinguishing criteria, such as for example wall thickness, wall thickness trend, magnetic permeability and heat conductivity can be distinguished.

[0041] The cross section of the fixedly arranged stator shaft 46 of the stator 42 of the eddy current brake 12 according to the invention in the combined axial / radial configuration form 40 is derived in more detail in a schematic manner by the diagram according to Figure 4 .

[0042] It is derivable from the cross-sectional diagram according to Figure 4 that the fixedly arranged stator shaft 46 is penetrated by a line 70 for a cooling medium 94. The line 70 extends perpendicular to the plane of the drawing according to Figure 4 . At the outer periphery of the line 70 for the cooling medium 94 a current-carrying conductor 72 is arranged for example with a deviation 78 of 90°. Figure 4 It is shown that the current-carrying conductor 72 can be arranged in the material 74 of the stator shaft 46 for example in the 12 o'clock position 80, in the 3 o'clock position 82, in the 6 o'clock position 84 or in the 9 o'clock position 86. It goes without saying that with regard to the arrangement of the current-carrying conductor 72 in the material 74 of the stator shaft 46 also a deviation different from 90° shown in Fig. 1 can be chosen. Figure 4 .

[0043] In the diagram according to Figure 4The cross section of the stator shaft 46 is shown enlarged in the view of Fig. 6, the outer circumference of the stator shaft 46 being denoted by the reference numeral 76.

[0044] It is derived from the view of Fig. 6 that the stator shaft 46 is traversed by the cooling medium 94 starting from the inflow side 88. After traversing the fixedly arranged stator core 44 of the stator 42, the cooling medium 94 again flows out of the stator shaft 46 on the outflow side 90. Figure 5 It is derived from the view of Fig. 6 that the stator shaft 46 is traversed by the cooling medium 94 starting from the inflow side 88. After traversing the fixedly arranged stator core 44 of the stator 42, the cooling medium 94 again flows out of the stator shaft 46 on the outflow side 90. Figure 5 It is shown that the cooling medium 94 flows along the flow path 92. After the cooling medium 94 has entered, the flow of the cooling medium 94 on the second end side 56 of the stator core 44 diverges in accordance with its flow path 92, so that the field winding 48 or the permanent magnet arranged in the axial position 50 on the second end side 56 is cooled first. Subsequently, before the cooling medium 94 cools the first end side 54 of the stator core 44 and the field winding 48 or the permanent magnet arranged in the axial position 50 there, respectively, along its flow path 92, the cooling medium 94 traverses the stator core 44 along its circumferential side 58 in the direction of its flow path 92 and dissipates heat from the field winding 48 or the permanent magnet accommodated in the radial position 52 at the circumferential side 58.

[0045] The heated cooling medium 94 again flows out on the outflow side 90 through the rigidly or fixedly arranged stator shaft 46 and carries away waste heat from the stator core 44 and thus cools the stator core and the field winding 48 or the permanent magnet accommodated at the stator core. Due to the minimized inner cavity 66 for the cavity 68 in the interior of the rotor 60 which can move relatively, that is to say rotate, about the stator core 44, the rotor can likewise be cooled by the guided flow path 92 of the cooling medium 94 at the outer surface of the stator core 44. There is thus the possibility that the eddy current brake 12 in the form of the axial / radial configuration 40 according to the application is constructed very compactly and that the waste heat occurring in the operation of the eddy current brake is carried away not only from the stator core 44 but also from the rotor 60 first and second material 62, 64 due to the minimized inner cavity 66.

[0046] The brake device 10 according to the application, which is realized in the combined axial / radial design 40, is preferably designed as an eddy current brake 12, which requires a very small installation space and can be used to induce a magnetic field or an eddy current on the basis of the use of all faces of the rotor, that is to say the first and second end sides 96, 98 and the peripheral side face 100, so that the very compactly designed eddy current brake 12 in the combined axial / radial design 40 can exert a great braking action in the smallest possible installation space. Since a very efficient cooling is achieved by means of the design of the flow path 92 through the stator core 44, the waste heat formed during braking can be removed very efficiently, more precisely not only with respect to the stator core 44 of the stator 42 of the eddy current brake 12 in the combined axial / radial design 40, but also with respect to the rotor 60 which comprehensively surrounds the stator core 44 of the stator 42 of the eddy current brake 12.

[0047] The application furthermore relates to the use of the brake device 10, which is designed as the eddy current brake 12 in the combined axial / radial design 40, in vehicles for passenger transport, whether passenger cars, buses, vans, transport vehicles or commercial vehicles, two-wheeled vehicles, three-wheeled vehicles or multi-wheeled vehicles, military vehicles, lorries, tractors or rail vehicles.

[0048] The application is not limited to the embodiments described here and aspects derived therefrom. Rather, a plurality of variants within the scope of the person skilled in the art can be realized within the scope defined by the claims.

Claims

1. A brake device (10) for a vehicle, in particular an eddy current brake (12) for a vehicle, wherein The brake device (10) comprises a magnet element (24) and a brake element (18) which are configured symmetrically relative to a symmetry axis (16), characterized in that the brake device (10) is embodied in a combined axial / radial configuration (40), wherein a stator (42) is surrounded by a rotor (60).

2. The brake device (10) according to claim 1, characterized in that The rotor (60) completely surrounds the stator (42).

3. The brake device (10) according to claims 1 and 2, characterized in that The rotor (60) comprises a first material (62) which is mounted at the end sides (96, 98) and a second material (64) which forms the peripheral side surface (100) thereof.

4. The brake device (10) according to claims 1 to 3, characterized in that The cavity (68) between the rotor (60) and the stator (42) is minimized in terms of its volume.

5. The brake device (10) according to claims 1 to 4, characterized in that The stator (42) has a peripheral side surface (58) at which the field windings (48) or permanent magnets arranged in the radial position (52) are located.

6. The brake device (10) according to claims 1 to 5, characterized in that The stator (42) has first and second end sides (54, 56) at which the field windings (48) or permanent magnets arranged in the axial position (50) are located.

7. The brake device (10) according to claims 3 to 6, characterized in that The field windings (48) in the axial position (50) and the radial position (52) of the stator (42) arranged fixedly correspond to the first and second materials (62, 64) of the rotor (60) which surrounds the stator.

8. The brake device (10) according to claims 1 to 7, characterized in that The stator axis (46) of the stator (42) forms an inflow side (88) and an outflow side (90) for a cooling medium (94) which flows through the stator (42).

9. The brake device (10) according to claims 1 to 8, characterized in that The flow path (92) of the cooling medium (94) extends through the stator core (44) of the stator (42) in such a way that it comprises the first and second end sides (54, 56) and the peripheral side surface (58) of the stator core (44).

10. The brake device (10) according to claims 1 to 9, characterized in that The flow path (92) of the cooling medium (94) comprises the stator core (44) of the stator (42) and the rotor (60).

11. A brake device (10) according to claims 3 to 10, characterized in that The first and second materials (62, 64) of the rotor (60) have different electrical conductivity, different wall thicknesses, different wall thickness trends, different magnetic permeability and different thermal conductivity.

12. Use of the brake device (10) according to any one of claims 1 to 11 in a vehicle for passenger transport, a transport vehicle or a utility vehicle, a two-wheeled vehicle, a three-wheeled vehicle or a multi-wheeled vehicle, a military vehicle, a bus, a truck-trailer or a rail vehicle.

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