BRAKE ARRANGEMENT AND METHOD FOR BRAKING A MOTOR VEHICLE

Abstract

The present development relates to a method for braking a motor vehicle and a brake arrangement (10) for a motor vehicle (1), comprising: - a first electric motor (31) which can be coupled to a first wheel (21) or to a first axle (11) of the motor vehicle (1) in a torque-transmitting manner, - a second electric motor (32) which can be coupled to a second wheel (22) or to a second axle (12) of the motor vehicle (1) in a torque-transmitting manner, - an electrical energy storage device (16) which can be coupled to the first electric motor (31) and to the second electric motor (32), and - with a controller (18) which is designed to operate the first electric motor (31) in a generator mode for braking the motor vehicle (1) and to supply at least part of the electrical energy recuperated in generator mode by the first electric motor (31) to the second electric motor (32) for generating a braking torque or drive torque acting on the second wheel (22) or the second axle (12).

Description

Technical FieldThe present development relates to a brake arrangement for a motor vehicle, in particular for an electrically operated motor vehicle, and to a method for braking the motor vehicle.BackgroundIn electric vehicles which are operated with at least two electric motors or electric machines, the mode of operation of the electric motors connected to the drive train or integrated into the drive train can be adapted as required both to the traction of the motor vehicle and to the braking deceleration of the motor vehicle. For a braking process, an electric motor can basically be operated in a generator mode which allows kinetic energy to be converted into electrical energy which can then be supplied to a motor vehicle battery.In addition, such electric vehicles can also be equipped with conventional hydraulic brakes or friction brakes. However, these have a certain degree of wear due to their design, so that the braking of the motor vehicle by means of one or more electric motors in the generator mode is to be preferred for long-term operation of the motor vehicle and for energy saving.Finally, if a method for braking a motor vehicle is known from DE 10 2011111 594 A1, wherein an electric machine is electrically connected to an electrical energy store and in a first operating mode the electric machine is operated as a generator for generating a generator braking torque, and wherein in a second operating mode the at least one electric machine thus supplies electrical energy from the energy store such that a braking torque directed opposite to the driving torque is generated by the at least one electric machine.In the second operating mode of the electric machine, electric energy is thus extracted from the energy store, which is consequently no longer available following the braking process.In this respect, the object of the present development is to provide an improved braking device or an improved method for braking a motor vehicle, which enables particularly wear-free long-term operation of the motor vehicle or of the brake system and which furthermore has proven to be particularly energy-efficient. The desired further development should furthermore be able to be realized as far as possible without or only with minimal additional outlay on apparatus and largely be able to rely on existing components of the motor vehicle.Advantageous EmbodimentsIn one aspect of the present development, a brake assembly for a motor vehicle is provided. The brake arrangement comprises a first electric motor which can be coupled to a first wheel or to a first axle of the motor vehicle in a torque-transmitting manner or is coupled thereto. The brake arrangement further comprises a second electric motor, which can be coupled to a second wheel or to a second axle of the motor vehicle in a torque-transmitting manner or is already coupled thereto.The brake arrangement further comprises an electrical energy store, which can be coupled to the first electric motor and to the second electric motor or is coupled thereto. Further, the brake assembly includes a controller. The controller is configured to operate the first electric motor in a generator mode for braking the motor vehicle and to supply at least a portion of the electrical energy recovered by the first electric motor in the generator mode to the second electric motor for generating a braking torque or drive torque acting on the second wheel or the second axle.In other words, for the braking of the motor vehicle, the two electric motors can be operated in an opposing manner. The first electric motor may apply a first braking deceleration or a first braking torque to the first wheel or the first axle in the recuperation mode. In this case, electrical energy is recuperated in or by means of the first electric motor, i.e. kinetic energy of the motor vehicle is converted into electrical energy.At least a portion of the recovered electrical energy that can be provided by the first electric motor is supplied to the second electric motor. The second electric motor is operated in a drive mode, namely in such a way that it exerts either a braking torque acting on the second axle or second wheel or a locking torque acting on the second axle or on a second wheel. The second electric motor is accordingly operated by the controller in such a way that it consumes or converts electrical energy and ultimately exerts a braking torque or drive torque on the second wheel or the second axle which is in motion.This brake arrangement can in principle be operated in the described manner completely independently of the respective state of charge of the electrical energy store.The operation of the brake arrangement described here, namely the provision of energy recuperated by means of the first electric motor to the second electric motor for braking or driving the second wheel or the second axle, is advantageously used when the electrical energy store of the motor vehicle is charged at least up to a predetermined threshold value and is only limitedly, or no longer capable of absorbing further electrical energy in that state of charge.The electrical energy recovered by means of the first electric motor can nevertheless then be used by the second electric motor for braking the second wheel or the second axle, resulting overall in an extremely energy-favorable operation of the motor vehicle and of the brake arrangement. For operating the second electric motor, in particular for braking the second wheel or the second axle, no electrical energy has to be taken from the electrical energy store. After the end of the braking process, the electrical energy store can still have a maximum state of charge which is then available for renewed acceleration of the motor vehicle.The electrical energy recovered, i.e. recovered, by the first electric motor can be used on the side of the second electric motor either for generating a further braking torque or for generating a further driving torque which acts on the second axle or on a second wheel.When a further braking torque is generated, the second electric motor is operated virtually in the opposite direction to its traction direction. The torque emanating from the electric motor and acting on the second axle or the second wheel acts as a quasi-braking torque. In a further operating mode, however, it is also conceivable for the second electric motor to exert a drive torque on the second axle or the second wheel and thus counteract the braking action of the first electric motor.The overall braking power of the motor vehicle can be reduced as a result. However, in an overall consideration of the brake arrangement, advantages result in that the conversion of kinetic energy of the motor vehicle on the side of the first electric motor into recovered electrical energy and the reconversion of the recovered electrical energy into a braking or driving torque on the side of the second electric motor are respectively lossy. In other words, and when the second electric motor uses the re-pumped electric energy provided by the first electric motor to generate a drive torque acting on the second wheel or the second axle, this drive torque will always be smaller than the brake torque that the first electric motor generates in the generator mode. In total, a net braking effect is thus always obtained even in the case of a fully charged electrical energy store without the need to use or claim optional friction brakes of the motor vehicle. However, this makes it possible at least to reduce the torque required at a friction brake of the motor vehicle and thus to increase the service life of the brake or to minimize its wear.Furthermore, the controller may be configured to transmit the recovered electrical energy provided by the first electric motor to the second electric motor with the lowest possible efficiency and / or to operate the second electric motor with a comparatively low efficiency, such that the second electric motor has the highest possible or comparatively high power loss for generating the lowest possible or comparatively low drive torque.In a further operating or braking mode of the brake arrangement, however, it can also be provided that the controller operates both the first electric motor and the second electric motor in the generator mode, such that the first and second electric motors re-generate electrical energy, but then feed it into the electrical energy store, for example. Such an operating mode is provided in particular when the electrical energy store has a sufficient residual capacity to absorb and store the electrical energy recovered by means of the first electric motor and also by means of the second electric motor.As soon as the electrical energy store reaches a state of charge of a predefined threshold value, for example when the electrical energy store has a maximum state of charge, the brake arrangement can switch over into the mode described further above, after which the electrical energy recovered by the first electric motor is at least partially supplied to the second electric motor in order to generate a braking or driving torque acting on the second wheel or the second axle.According to a further embodiment of the brake arrangement, the controller is designed to supply at least a portion of the electrical energy recovered by the first electric motor to the second electric motor, bypassing the electrical energy store, for generating a braking or driving torque acting on the second wheel or the second axle.In this way, an unnecessary load or a critical overload state of the electrical energy store as a result of the recuperation of electrical energy by the first electric motor can be avoided. Likewise, in this way, the electrical energy recovered by the first electric motor can be used to actively generate the braking torque acting on the second wheel or the second axle, so that overall an increased amount of braking power can be achieved which originates both from the first wheel or the first drive axle and from the second wheel or the second drive axle. Even when a drive torque is generated by the second electric motor, a considerable braking power can still be produced overall for the vehicle.In the case of direct diversion of recovered electrical energy from the first electric motor to the second electric motor, the brake arrangement can be operated in a particularly energy-efficient manner. Any conduction or charging losses which otherwise arise when the recovered electrical energy is temporarily stored, for example in the electrical energy store, can be avoided extensively in this way.According to a further embodiment of the brake arrangement, the controller is configured to supply the electrical energy recuperated by the first electric motor for a braking process completely to the second electric motor in order to generate a braking torque acting on the second wheel or the second axle. In this way, the second wheel or the second axle can experience a maximum braking torque without an optional friction brake or hydraulic brake having to be actuated for this purpose and / or without electrical energy having to be taken from the electrical energy store.Overall, when the electrical energy recovered by the first electric motor is supplied completely to the second electric motor for braking the second wheel or the second axle, the electrical braking power of the brake arrangement can be maximized. The optional friction brake or hydraulic brake can be saved in this respect and the wear associated therewith can be reduced. In addition, this can prevent overheating or brake fading during long downhill travel without the battery being able to charge, which can be associated with a gain in safety.According to a further embodiment of the brake arrangement, the controller is configured to regulate the supply of electrical energy recuperated by means of the first electric motor to the second electric motor as a function of a state of charge of the electrical energy store. If the electrical energy store has, for example, a maximum fill or charge state when the braking process is initiated, it is provided that the electrical energy recovered by the first electric motor during the braking process is supplied completely or almost completely to the second electric motor for generating a braking or drive torque acting on the second wheel or the second axle.If the state of charge of the electrical energy store is significantly below a maximum state of charge and the electrical energy store has sufficiently free capacity, both, namely the first and the second electric motor, can be operated in the generator mode in each case, such that at least some of the respectively recovered electrical energy from the first and the second electric motor can be supplied to the energy store. In this way, the recuperation of electrical energy can be accelerated and the electrical energy store can be charged particularly rapidly. However, if the electrical energy store reaches a state of charge above a predefined threshold value, it is provided that at least a portion of the electrical energy recovered by the first electric motor is supplied to the second electric motor for generating a deceleration, a braking torque or a driving torque to the second wheel or the second axle.According to a further embodiment of the brake arrangement, the controller is configured to supply the electrical energy recovered by means of the first electric motor completely or almost completely to the second electric motor for generating a braking or driving torque acting on the second wheel or the second axle in the case of a state of charge of the electrical energy store lying above a predefined threshold value. In this way, a sufficient power loss for the recovered electrical energy can be provided in a particularly simple manner.In this way, it can be effectively prevented that the electrical energy store is supplied with additional electrical energy from the generator mode of the first electric motor, which could possibly lead to damage to the electrical energy store.According to a further embodiment of the brake arrangement, the first electric motor is coupled to at least one front wheel or to a front axle in a torque-transmitting manner, and the second electric motor is coupled to at least one rear wheel or to a rear axle in a torque-transmitting manner. However, the first and second electric motors can also change their roles. Thus, it can also be provided in particular that the second electric motor is operated in the generator mode when the motor vehicle is braked, and that electrical energy recovered by the second electric motor is supplied at least partially to the first electric motor, which uses that recovered and provided electrical energy for generating a braking or drive torque acting on the first wheel or the first axle.In further embodiments, it is further conceivable that the first electric motor is coupled to a second wheel of a front axle or of a rear axle in a torque-transmitting manner and the second electric motor is coupled to a first wheel of the front axle or of the rear axle in a torque-transmitting manner. It is conceivable in principle that the first electric motor can be coupled in a torque-transmitting manner exclusively to one or more wheels of the front axle and that the second electric motor can be coupled in a torque-transmitting manner exclusively to one or both wheels of the rear axle.In other embodiments, a reverse arrangement may also be provided, according to which the first electric motor is coupled to one or both wheels of a rear axle in a torque-transmitting manner, and wherein the second electric motor is coupled to one or both wheels of the front axle in a torque-transmitting manner.In principle, it is conceivable that the first electric motor is coupled exclusively to the first axle, for example to a front axle, and that the second electric motor is coupled exclusively to the second axle, for example to a rear axle. In this way, the different braking or locking torques, which can be generated in the generator mode of the first electric motor on the one hand and which can be generated in the drive mode of the second electric motor on the other hand, can act on different axles of the motor vehicle.Finally, in further embodiments, it is also conceivable that the first electric motor is coupled to a first wheel of the front axle and that the second electric motor is coupled to a second wheel of the same axle, i.e. to the front axle. Likewise, the first and second electric motors can be provided on different wheels of the rear axle and can be respectively coupled thereto. Thus, the controller can be further configured to control the respective braking or drive torque, which is transmitted or exerted by the first electric motor and the second electric motor to the respective wheels on one and the same axle, as required.According to a further embodiment of the brake arrangement, it has a third electric motor and a fourth electric motor. The electric motors are each coupled to a wheel of the motor vehicle in a torque-transmitting manner. For example, the third electric motor may be torque-transmittingly coupled to a second wheel of the first axle and the fourth electric motor may be torque-transmittingly coupled to a second wheel of the second axle of the motor vehicle.For braking the motor vehicle, for example, the first and third electric motors, preferably those electric motors which are provided on one and the same axle of the motor vehicle, can be operated in the generator mode, while the second and fourth electric motors, which are likewise provided on a common axle of the motor vehicle, are actively and fed by recovered electrical energy, brake or drive the respective wheels or the relevant axle, or exert a braking or drive torque on the respective wheels or the axle.According to a further aspect of the present development, a motor vehicle having a motor vehicle body is finally provided. The motor vehicle comprises a brake arrangement described above. The motor vehicle can be implemented, for example, as a passenger car, as a sport utility vehicle (SUV), or as a transport vehicle, as well as as as a bus or truck. Since the motor vehicle comprises a brake arrangement described above, all features, advantages and properties described above with regard to the brake arrangement also apply equally to the motor vehicle; and vice versa.In a further aspect of the present development, a method for braking a motor vehicle by means of a motor vehicle brake arrangement is finally provided. The motor vehicle brake arrangement has a first electric motor which can be coupled to a first wheel or to a first axle of the motor vehicle in a torque-transmitting manner or is coupled thereto.The motor vehicle or the motor vehicle brake arrangement further comprises a second electric motor, which can be coupled to a second wheel or to a second axle of the motor vehicle in a torque-transmitting manner or is coupled thereto. For braking the motor vehicle, provision is made in terms of method technology for the first electric motor to be operated in a generator mode and for at least some of the electrical energy recovered by the first electric motor in the generator mode to be supplied to the second electric motor. The second electric motor then exerts a braking or driving torque acting on the second wheel or the second axle by means of the recovered electric energy supplied by the first electric motor.Typically, the method described here for braking the motor vehicle can be carried out using a previously described brake arrangement for a motor vehicle. In this respect, all features, advantages and properties described above and with regard to the brake arrangement also apply equally to the method for braking the motor vehicle; and vice versa.Brief Description of the FiguresFurther objects, features and advantageous embodiments of the present development are explained in the following description of an exemplary embodiment. The following are shown here: FIG. 1 shows a schematic side view of a motor vehicle on an inclined plane, FIG. 2 shows a block diagram of a brake system or of a motor vehicle according to a first specific embodiment, FIG. 3 shows a block diagram of a brake system or of a motor vehicle according to a second specific embodiment, and FIG. 4 is a flow chart of a braking method using the brake system.Detailed DescriptionFIG. 1 shows a schematic illustration of a motor vehicle 1 having a motor vehicle body 2. The motor vehicle 1 is located here on an inclined plane and is to be braked for controlled driving. FIG. 2 shows a block diagram of a brake arrangement 10 of the motor vehicle 1. The brake arrangement 10 comprises a first electric motor 31 and a second electric motor 32. the two electric motors 31, 32 are operable by means of a controller 18, for example, in a traction mode or in a generator mode. In traction mode, the electric motors 31, 32 generate a mechanical torque using or consuming electrical energy typically provided by an electrical energy store 16, for example a battery electrical energy store 16.The controller 18 is likewise coupled to the battery or to the electrical energy store 16 and can determine or measure in particular the state of charge of the electrical energy store 16. Optionally, the motor vehicle 1 has a power generation device 14, by means of which electrical energy can be provided on board the motor vehicle. The power generation device can have an internal combustion unit, for example an internal combustion engine or a fuel cell. The electrical energy that can be generated thereby can either be made available directly to the electric motors 31, 32 or it can be stored at least partially or else completely in the electrical energy store 16, and can therefore be buffered there.In the exemplary embodiment of FIG. 2, the first electric motor 31 is coupled in a torque-transmitting manner to a first axle 11, for example a front axle. In the exemplary embodiment shown in FIG. 2, the second electric motor 32 is coupled to a second axle 12 in a torque-transmitting manner. On the first axle 11, a first wheel 21 and a third wheel 23 are provided. On the second axle 12, a second wheel 22 and a fourth wheel 24 are provided.In the traction mode, the first electric motor 31 and the second electric motor 32 can each exert a drive torque on the axles 11, 12, as a result of which the associated wheels 21, 22, 23, 24 are rotationally set in motion. For braking the motor vehicle 1, it is provided that the first electric motor 31 is switched into a generator mode in which it exerts a braking torque on the first axle 11 and, as a result of this braking torque, recuperates electrical energy. The electrical energy recovered by the first electric motor 31 can in principle be fed into the electrical energy store 16.However, if the electrical energy store 16 is almost completely charged or the electrical energy store 16 is in a state of charge above a predefined maximum state of charge, the feeding of further recuperated electrical energy into the electrical energy store 16 would have a more disadvantageous effect with regard to the continuous operation of the electrical energy store 16.Instead of this, it is now provided for this case that the second electric motor 32 absorbs at least a portion of the electrical energy recovered by the first electric motor 31 and converts this into a torque which acts as a braking torque or as a driving torque on the second axle 12 and thus as a braking or driving torque on the wheels 22, 24.In this way, the electrical energy, which may be re-pumped by the first electric motor 31, can be transferred directly, instantaneously and / or, bypassing the electrical energy store 16, to the second electric motor 32, which can actively use that electrical energy for generating a braking or driving torque, which acts on the second axle 12 and thus on the wheels 22, 24.In further exemplary embodiments, it is finally conceivable for the roles of the first electric motor 31 and the second electric motor 32 to be interchanged. Thus, it is also conceivable in principle that the second electric motor 32 recuperates electrical energy and conducts at least a portion of the recuperated electrical energy to the first electric motor 31, which, as a result of such an energy input, generates a braking or drive torque which acts on the first axle 11 and thus on the wheels 21, 23.In the further exemplary embodiment according to FIG. 3, two further electric motors 33, 34 are provided. Their mode of operation is quite similar to the electric motors 31, 32 as explained above in the example of FIG. 2. In the exemplary embodiment of FIG. 3, a first wheel 21 of a front axle 11 can be coupled to the first electric motor 31 in a torque-transmitting manner. A second wheel 22 of a rear axle 12 can be coupled to the second electric motor 32 in a torque-transmitting manner. The third electric motor 33 can be coupled to a third wheel 23 of the front axle 11 in a torque-transmitting manner, and the fourth electric motor 34 can be coupled to a fourth wheel of the second axle 12, and therefore to the rear axle 12 in a torque-transmitting manner.In this embodiment, all electric motors 31, 32, 33, 34 can be operated completely independently of one another. It is conceivable in principle that one or two of the electric motors 31, 32, 33, 34, for example the motors 31, 33, are operated in the generator mode and that the electrical energy re-generated in this case is used for the two other electric motors 32, 34 to generate a braking or driving torque present at the respective wheel 22, 24.It is also conceivable that at least one electric motor 31, 33 of the front axle 11 is operated in the generator mode and that the electrical energy recovered in this case is conducted to at least one of the electric motors 32, 34 of the rear axle 12 so that the corresponding electric motor 32, 34 can exert a required braking or drive torque on the respectively associated wheel 22, 24.It is equally conceivable that at least one of the electric motors 32, 34 of the rear axle 12 is operated in the generator mode and that the recovered electrical energy arising in this case is transmitted to at least one of the two electric motors 31, 33 of the front axle 11 so that these can exert a corresponding braking or drive torque on at least one relevant wheel 21, 23.Finally, in the embodiment according to FIG. 3, it is also conceivable that electric motors 31, 32 or electric motors 32, 34 which are associated with the same axle 11, 12 can be operated in pairs in each case in the generator mode for generating electrical energy and in the consumption mode for generating a braking or drive torque. For example, one of the electric motors 32, 34 of the rear axle 12 can be transferred into the generator mode, so that the other of the electric motors 32, 34 absorbs the electrical energy recuperated in this case and exerts a corresponding braking or drive torque on the wheel 22, 24 assigned to it.The flow chart of FIG. 4 once again illustrates the individual method steps for braking the motor vehicle. In a first step 100, the first electric motor 31 is operated in a generator mode. In step 102, at least a portion of the electrical energy recovered by the first electric motor 31 in the generator mode is supplied to the second electric motor 32. In step 104, the recovered electrical energy supplied to the second electric motor 32 is used to generate a braking or driving torque acting on the second wheel 22 or the second axle 12.The embodiments shown merely show possible configurations of the development, for which further numerous variants are conceivable within the scope of the development. The exemplary embodiments shown by way of example should in no way be interpreted as restrictive with regard to the scope, applicability or configuration possibilities of the development. The present description will only teach one or some possible implementation(s) of an embodiment to those skilled in the art. Thus, many modifications can be made to the function and arrangement of elements described without departing from the scope of protection defined by the following claims or the equivalents thereof.LIST OF REFERENCE CHARACTERS1 Motor vehicle 2 Motor vehicle body 10 Brake arrangement 11 Axle 12 Axle 14 Power generating device 16 Electrical energy store 18 Controller 21 Wheel 22 Wheel 23 Wheel 24 Wheel 31 Electric motor 32 Electric motor 33 Electric motor 34 Electric motorReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 20111111 594 A1

[0004]

Claims

Brake arrangement (10) for a motor vehicle (1), comprising: - a first electric motor (31), which can be coupled to a first wheel (21) or to a first axle (11) of the motor vehicle (1) in a torque-transmitting manner, - a second electric motor (32), which can be coupled to a second wheel (22) or to a second axle (12) of the motor vehicle (1) in a torque-transmitting manner, - an electrical energy store (16), which can be coupled to the first electric motor (31) and to the second electric motor (32), and - having a controller (18), which is designed to connect the first electric motor to the second electric motor (31) and to the second electric motor (32), and, for braking the motor vehicle (1), to operate the first electric motor (31) in a generator mode and to supply at least a portion of the electrical energy recovered by the first electric motor (31) in the generator mode to the second electric motor (32) in order to generate a braking torque or driving torque acting on the second wheel (22) or the second axle (12).Brake arrangement (10) according to Claim 1, wherein the controller (18) is configured to supply at least some of the electrical energy recovered by the first electric motor (31) to the second electric motor (32), bypassing the electrical energy store (16), in order to generate a braking torque or drive torque acting on the second wheel (22) or the second axle (12).Brake arrangement (10) according to Claim 1 or 2, wherein the controller (18) is designed to supply the electrical energy recuperated by the first electric motor (31) for a braking operation completely to the second electric motor (32) in order to generate a braking torque or drive torque acting on the second wheel (22) or the second axle (12).Brake arrangement (10) according to one of the preceding claims, wherein the controller (18) is configured to regulate the supply of electrical energy recuperated by means of the first electric motor (31) to the second electric motor (32) as a function of a state of charge of the electrical energy store (16).Brake arrangement (10) according to one of the preceding claims, wherein the controller (18) is configured, in the case of a state of charge of the electrical energy store (16) lying above a predefined threshold value, to supply the electrical energy recovered by means of the first electric motor (31) completely or almost completely to the second electric motor (32) in order to generate a braking torque or drive torque acting on the second wheel (22) or the second axle (12).Brake arrangement (10) according to one of the preceding claims, wherein the first electric motor (31) is coupled to at least one front wheel (21, 23) or to a front axle (11) in a torque-transmitting manner, and wherein the second electric motor (32) is coupled to at least one rear wheel (22, 24) or to a rear axle (12) in a torque-transmitting manner.Brake arrangement (10) according to one of the preceding claims, wherein the first electric motor (31) is coupled in a torque-transmitting manner to a first wheel (21, 22) of a front axle (11) or of a rear axle (12), and wherein the second electric motor (32) is coupled in a torque-transmitting manner to a second wheel (23, 24) of the front axle (11) or of the rear axle (12).Brake arrangement (10) according to one of the preceding claims, which has a third electric motor (33) and a fourth electric motor (34), and wherein the electric motors (31, 32, 33, 34) are coupled in a torque-transmitting manner to a respective wheel (21, 22, 93, 24) of the motor vehicle (1).Motor vehicle (1) having a motor vehicle body (2) and having a brake arrangement (10) according to one of the preceding claims.Method for braking a motor vehicle (1) by means of a motor vehicle brake arrangement (10) which has a first electric motor (31) which can be coupled in a torque-transmitting manner to a first wheel (21) or to a first axle (11) of the motor vehicle (1), which has a second electric motor (32) which can be coupled in a torque-transmitting manner to a second wheel (22) or to a second axle (12) of the motor vehicle (1), and wherein, for braking the motor vehicle (1),: - the first electric motor (31) is operated in a generator mode, - at least some of the electrical energy recovered by the first electric motor (31) in the generator mode is fed to the second electric motor (32), and - the second electric motor exerts a braking torque or drive torque acting on the second wheel (22) or the second axle (12) by means of the recovered electrical energy fed by the first electric motor (31).

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