motor vehicle

Abstract

Motor vehicle comprising a braking device (7) with at least one hydraulic brake circuit (8, 9) and an electric machine (1) designed for recuperation during a braking process, wherein the stator of the electric machine (1) is mounted on the body (3) by means of at least one bearing (2, 30, 38, 50) designed to absorb a reaction torque generated by the recuperation and corresponding to the recuperation torque (18), wherein a reaction torque acting on the at least one bearing (2, 30, 38, 50) can be detected, wherein a braking force generated by means of the braking device (7) can be varied depending on the recuperation torque (18) thus detected, characterized in that the bearing (2, 30, 38, 50) has at least one pressure chamber (31 - 34, 44, 45, 54 - 57) which is connected to a hydraulic circuit (15, 35, 36, 46, 58, 59) is connected, with the hydraulic circuit (15, 35, 36, 46, 58,59) is connected to the brake circuit (8), wherein a recuperation torque (18) acting on the bearing (2, 30, 38, 50) causes a change in the quantity of a hydraulic fluid in the hydraulic circuit (15, 35, 36, 46, 58, 59) and a reduction in the quantity of the hydraulic fluid in the brake circuit (8).

Description

[0001] The invention relates to a motor vehicle comprising a braking device with at least one hydraulic brake circuit and an electric machine designed for recuperation during a braking process.

[0002] Such motor vehicles are known from the prior art. These vehicles feature an electric machine as a drive unit, either as an electric drive or as a support system in the form of a hybrid drive. In both cases, the electric machine can be controlled so that energy can be recovered during braking through recuperation, which can then be stored, for example, in a battery or other energy storage device. This energy can then be used to drive the vehicle axle to which the electric machine is assigned.

[0003] During braking, it is therefore desirable to recover as much energy as possible through recuperation. The electric motor should thus recuperate to the maximum extent possible, thereby generating a braking effect through the recuperation torque. For this to be effective, the braking torque generated by the braking system must be such that the maximum recuperation torque can still be utilized. This means that a hydraulic braking system acting in parallel with the electric motor should apply less braking force during recuperation, so that as much of the energy dissipated during braking as possible can be converted into electrical energy and recovered. However, the braking effect achieved through recuperation is not constant for a variety of reasons, but depends, for example, on the battery's state of charge or the temperature of the electric motor.

[0004] It is therefore necessary that, depending on the recuperation or the specific recuperation torque, the total braking power can be distributed between the hydraulic braking system and the braking power generated by recuperation. This capability is also referred to as "blending capability".

[0005] From DE 10 2012 020 880 A1, a motor vehicle with a hybrid or electric drive is known in which the braking power is distributed between the recuperation power of the electric motor and the hydraulic braking system by connecting an actuator designed as a ball ramp to the output shaft of the electric motor and the hydraulic braking system, whereby the effect on the braking system is proportional to the torque transmitted by the output shaft. Consequently, a transmission from the rotating system of the output shaft to the body-mounted system of the braking system is necessary, which requires computational means for determining and implementing the modulation strength, in particular the volume and / or pressure variation. Furthermore, availability and safety considerations must be incorporated into the calculation.Furthermore, a disadvantage of such a solution is that, during highly dynamic changes in the machine's rotational speed, a significant proportion of the torque is measured at its shaft due to its own inertia, which, however, should not compensate for the braking force generated by the braking device.

[0006] The invention is therefore based on the objective of providing an improved motor vehicle that does not require expensive computing power.

[0007] To solve this problem, a motor vehicle is proposed according to the invention, comprising a braking device with at least one hydraulic brake circuit and an electric machine designed for recuperation during a braking process, wherein the stator of the electric machine is mounted on the body by means of at least one bearing, which is designed to receive a reaction torque generated by the recuperation and corresponding to the recuperation torque, wherein a reaction torque acting on the at least one bearing can be detected, and wherein a braking force generated by means of the braking device can be changed as a function of the recuperation torque thus detected.

[0008] The invention is based on the idea that the recuperation torque generated by the electric machine during braking is used, firstly, to brake the wheels and, secondly, as a reaction torque at the at least one bearing by which the electric machine, in particular the stator of the electric machine, is mounted to the vehicle body. Consequently, the reaction torque acting on the at least one bearing can be detected and used to determine the extent to which the electric machine is recuperating and, consequently, how much the braking force generated hydraulically by the braking device should be adjusted to maximize the recuperation torque. In contrast to the prior art, the recuperation torque is therefore not measured or determined at the rotating output shaft, but rather indirectly, but with respect to a vehicle body-mounted reference system.The data is captured. Therefore, it is not necessary to transfer it to the body-fixed reference frame. Consequently, a proportional change in the braking force generated by the braking device can be carried out depending on the recuperation torque.

[0009] Naturally, it is possible to equip a motor vehicle with multiple electric motors, for example, one electric motor per driven axle. Furthermore, it is possible to assign an electric motor to each wheel. The term "supporting the stator at the at least one bearing" refers to both direct and indirect support, such as via a housing.

[0010] Particularly preferably, the bearing of the motor vehicle according to the invention has at least one pressure chamber which is connected to a hydraulic circuit, wherein the hydraulic circuit is connected to the brake circuit, wherein a recuperation torque acting on the bearing causes a change in the quantity of a hydraulic fluid in the hydraulic circuit and a reduction in the quantity of the hydraulic fluid in the brake circuit.

[0011] Accordingly, it is intended that a recuperation torque acting on the bearing causes a deformation of the pressure chamber. This deformation of the pressure chamber results in a change in volume within the chamber, which is operatively connected to the hydraulic circuit. Since the hydraulic circuit is connected to the hydraulic brake circuit, a change in volume within the hydraulic circuit causes a certain amount of hydraulic fluid to flow from the brake circuit into the hydraulic circuit. For example, the pressure chamber in the bearing can be deformed in such a way that the volume of the hydraulic circuit increases. This reduces the pressure in the hydraulic circuit, causing hydraulic fluid to flow from the hydraulic brake circuit into the hydraulic circuit, thereby reducing the brake pressure in the brake circuit. Thus, depending on the recuperation torque acting on the bearing, a reduction in brake pressure or...The braking force is reduced to the extent that the electric motor decelerates the wheels of the vehicle axle assigned to it. Therefore, the braking force exerted by the braking device can be reduced to the degree that the electric motor recuperates energy, so that the maximum possible recuperation torque can be fully utilized and the total braking performance can be maintained.

[0012] According to a particularly preferred embodiment of the vehicle according to the invention, the bearing may have four pressure chambers, each paired and operatively connected to a hydraulic circuit. In this embodiment, the bearing is thus assigned four pressure chambers, which are paired, for example, diagonally, and each assigned to a hydraulic circuit or operatively connected to it. When a recuperation torque acts on the bearing, the pressure chambers assigned to one hydraulic circuit in pairs are deformed in the same direction, while the other two corresponding pressure chambers are also deformed, but in the opposite direction. That is, for example, two of the pressure chambers are compressed, and the pressure in the corresponding hydraulic circuit therefore increases.The two other pressure chambers are expanded accordingly, causing the pressure in the hydraulic circuit connected to the two expanded pressure chambers to decrease. The pressure conditions in both hydraulic circuits can then be used to control the brake pressure in the brake circuit of the braking device; in particular, the amount of hydraulic fluid drawn from the brake circuit can be determined, thus allowing the braking force generated by the braking device to be varied depending on the recuperation torque.

[0013] The vehicle according to the invention can be further preferably developed in such a way that the bearing has a bearing core connected to the stator, which exerts a force on one or more pressure chambers when a recuperation torque is applied. Accordingly, it is provided that the bearing has a bearing core that is connected to the stator of the electric machine. The bearing core is thus preferably arranged substantially parallel to the rotor axis of the electric machine, so that a recuperation torque generated by the machine can be transferred to the bearing core in such a way that the latter can introduce the recuperation torque into the bearing in a defined manner. In this context, a defined introduction of the recuperation torque into the bearing means that a defined deformation of the at least one pressure chamber can be achieved.The bearing core preferably has corresponding system sections by means of which it can exert a force on the pressure chambers assigned to it, provided that a recuperation moment acts on the bearing core.

[0014] The previously described embodiment of the motor vehicle according to the invention can preferably be further developed such that the bearing core comprises an inner and an outer bearing core part, wherein the stator of the electric machine is connected to the inner bearing core part, and at least one pressure chamber is provided between the inner and outer bearing core parts, the volume of which can be changed by a relative movement between the inner and outer bearing core parts. The embodiment is based on the idea that the bearing core is two-part, being divided into an inner bearing core part and an outer bearing core part. A recuperation torque generated by the electric machine is transmitted to the inner bearing core part via its stator.This causes the inner bearing core part to move relative to the outer bearing core part, thus changing the volume of the at least one pressure chamber located between the inner and outer bearing core parts. This change in volume within the pressure chamber varies the pressure or the amount of hydraulic fluid in the chamber, which in turn affects the hydraulic brake circuit of the braking device. This allows for a change in the braking force generated by the braking device, depending on the recuperation torque.

[0015] Furthermore, in the motor vehicle according to the aforementioned embodiment, the outer bearing core part can have at least one stop for the inner bearing core part, wherein, when a drive torque is applied, which is generated by the electric machine and introduced into the bearing via the inner bearing core part, the inner bearing core part is in contact with the outer bearing core part at the stop. This ensures that only a recuperation torque causes a change in volume in the pressure chamber between the inner and outer bearing core parts, and that when a drive torque is applied, the two bearing core parts are in contact with each other, thus preventing any change in volume in the pressure chamber. This ensures that a change in the braking force of the braking device only occurs when a recuperation torque is present and not when a drive torque is present.

[0016] Alternatively, the vehicle according to the invention can be provided with four pressure chambers between the inner and outer bearing core parts, the volumes of which can be changed in pairs during relative movement between the inner and outer bearing core parts. The inner bearing core part preferably has contact sections or vanes that, during rotational relative movement between the inner and outer bearing core parts, increase or decrease the volume of the pressure chambers arranged in pairs. This allows the four pressure chambers to be assigned in pairs to two hydraulic circuits, which are used to control the amount of hydraulic fluid drawn from the hydraulic brake circuit. Thus, a hydraulic circuit can, for example, be assigned to two pressure chambers in a crosswise configuration, or be operatively connected to them, which are compressed when a recuperation torque acts on the inner bearing core part.This will change the pressure in the corresponding hydraulic circuit, allowing it to be used for control, for example, of a valve. The other hydraulic circuit, which is operatively connected to the pressure chambers that expand when a recuperation torque is applied, can then be used to pump hydraulic fluid from the hydraulic brake circuit, thus reducing the braking torque generated by the braking device when a recuperation torque is present.

[0017] An alternative embodiment of the motor vehicle according to the invention provides that the pressure chambers are vulcanized into the bearing. This is particularly possible if the pressure chambers are arranged in a part of the bearing made of an elastomer.

[0018] The vehicle according to the invention may also be equipped with a locking element designed to separate the hydraulic circuit from the brake circuit. This locking element is preferably electrically controllable, allowing the hydraulic circuits to be separated from the brake circuit or connected as needed. In particular, there are situations in which modulation of the braking force generated by the braking device is undesirable, for example, during accelerated reversing, where the direction of the drive torques coincides with the recuperation torque during forward driving. Also particularly relevant are driving conditions in which the hydraulic stiffness of the brake circuit must be maintained at a consistently high level, for example, in the case of ABS control.

[0019] A particularly preferred embodiment of the motor vehicle according to the invention can provide that the hydraulic circuit is connected to the brake circuit by means of a pressure-controlled valve device, which is designed to establish a connection between the hydraulic circuit and the brake circuit when there is negative pressure in the hydraulic circuit and to block the connection otherwise. This makes it possible to extract hydraulic fluid from the brake circuit only when there is negative pressure in the hydraulic circuit, i.e., at the bearing side.This allows the system to control the pressure drop in the hydraulic circuit caused by a recuperation torque on the motor bearing. This allows a connection to be established to the brake circuit via the pressure-controlled valve assembly. Depending on the recuperation torque, hydraulic fluid can then be drawn from the brake circuit, thus reducing the braking force generated by the brake system. If there is no pressure drop in the hydraulic circuit, the connection is closed, preventing higher pressure in the brake circuit, such as during braking without recuperation torque, from affecting the bearing and thus preventing unnecessary loss of brake pressure.

[0020] A further development of the motor vehicle according to the invention preferably consists in the pressure-controlled valve assembly being configured to allow the recirculation of hydraulic fluid after the braking process and / or when the recuperation torque decreases. For this purpose, the valve assembly has a suitable arrangement of valves or pressure-controlled valves, for example, check valves. This enables additional states beyond those described above, such as the recirculation of hydraulic fluid after the braking process and / or a recuperation torque that decreases during the braking process. This ensures that all elements, in particular the bearings and the master cylinders or the tandem master cylinder of the brake system, can be returned to their initial positions after the braking process.Similarly, the pressure-controlled valve device makes it possible to ensure that, even during continuous braking where the recuperation torque decreases, for example due to a full battery or a failure of the recuperation power due to damage, hydraulic fluid can still be fed back into the brake circuit.

[0021] According to a further preferred embodiment of the invention, an orifice for filtering high-frequency components can be provided between one of the hydraulic circuits and the pressure-controlled valve assembly. Such an orifice allows high-frequency components in the pressure variation to be filtered out of the pressure chambers or the at least one pressure chamber.

[0022] The motor vehicle according to the invention can be further developed by providing at least two bearings, wherein the braking force can only be changed during opposing bearing movements. This prevents machine forces and torques not originating from recuperation torques from contributing to a change in the braking force generated by the braking device. It is thus ensured that hydraulic fluid is only drawn from the hydraulic brake circuit when a recuperation torque is present, i.e., when the wheels are braked to a corresponding extent by the electric motor due to recuperation, so that the braking effect by the braking device can be reduced.

[0023] Finally, a separating component can be provided that separates the pressure media present in the two circuits, i.e., the two hydraulic fluids, while simultaneously allowing pressure transmission. This allows different hydraulic fluids to be used in the two circuits. The separating component also serves a protective function against the brake circuit being drained in the event of a hydraulic leak. The separating component can, for example, be designed as a double-acting floating piston, actuated on one side by the hydraulic fluid present in the brake circuit (i.e., the brake fluid), and on the other side by the hydraulic fluid present in the hydraulic circuit. Since the floating piston has a limited range of motion, any fluid loss from the brake circuit is also limited.

[0024] The invention is explained in more detail below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 a section of a motor vehicle according to the invention; Fig. 2 an equivalent circuit diagram of a part of the motor vehicle according to the invention of Fig. 1 according to a first embodiment; Fig. 3 in equivalent circuit diagram according to a second embodiment; Fig. 4 a bearing of the motor vehicle according to a first embodiment; Fig. 5 a bearing of the motor vehicle according to a second embodiment; Fig. 6 a bearing of the motor vehicle according to a third embodiment, and Fig. 7 is an example of a separation component for separating the two circuits.

[0025] Fig. Figure 1 shows an electric machine 1 of a motor vehicle (not shown in detail). The electric machine 1 is mounted on the body 3 of the motor vehicle at three bearings 2 according to a 3-point mounting. In other words, a stator of the electric machine 1 is connected to the bearings 2. A bearing axis 4 of the bearings 2 is evidently running essentially parallel to the transverse direction of the motor vehicle, which coincides with a rotor axis 5 of the rotor 6 of the electric machine 1. A recuperation torque generated by the electric machine 1 is thus absorbed by the bearings 2, so that the recuperation torque also acts on the bearings 2 and can be detected there.

[0026] Fig. Figure 2 shows an equivalent circuit diagram of a part of the motor vehicle. The motor vehicle comprises a braking system 7 with two hydraulic brake circuits 8, 9, which, according to a black-and-white division, are assigned to the two axles of the motor vehicle or are operatively connected to the corresponding wheel brakes of the respective vehicle axle. In this embodiment, the hydraulic brake circuits 8, 9 are filled with hydraulic fluid via a tandem master cylinder 10 depending on the pedal position of a brake pedal 11, or the pressure in the hydraulic brake circuits 8, 9 is adjusted via the brake pedal 11. A brake booster 12 and, furthermore, two supply lines 13 leading to a reservoir, which is not shown in detail, can be arranged between the tandem master cylinder 10 and the brake pedal 11.

[0027] Fig. Figure 2 further shows that the brake circuit 8 has a connection point 14 through which the brake circuit 8 is connected to a hydraulic circuit 15. In the hydraulic circuit 15, Fig. 2 and Fig. Figure 3, in the form of an equivalent circuit diagram, shows that a bearing movement of the bearings 2, which are mounted on the body 3, corresponds to a movement of a piston 16, 17, provided that a recuperation torque 18 acts on the bearings 2. The equivalent circuit diagram is to be understood merely schematically, with specific embodiments of the bearings 2 being described below. Fig. 4 to 6 will be explained.

[0028] It is evident that the order according to Fig. Only opposing bearing movements affect the hydraulic circuit 15 or the brake circuit 8, as movements of pistons 16 and 17 in the same direction cancel each other out. This prevents machine torques or other accelerations on bearings 2 from having an undesirable effect on brake circuit 8. Brake circuit 8 is only affected by a reaction torque on bearings 2 caused by a recuperation torque 18, which results in opposing movements of pistons 16 and 17. When a recuperation torque 18 acts on bearings 2, pistons 16 and 17 move in opposite directions.This increases the volume of the hydraulic circuit 15, so that hydraulic fluid from the brake circuit 8 can flow into the hydraulic circuit 15 at the connection point 14, which leads to a decrease in the brake pressure in the brake circuit 8, so that the corresponding wheel brakes exert a lower braking force and thus the recuperation torque 18 can be used to brake the vehicle and thereby to generate energy.

[0029] An optional locking element in the form of a switching valve 19 is provided between the hydraulic circuit 15 and the brake circuit 8. This valve can be controlled by a control unit (not shown) depending on the driving conditions. This control unit can be an active electric switching valve, allowing the switching valve 19 to be opened and closed. If braking is to be performed without recuperation torque, the switching valve 19 can be closed, thus closing the brake circuit 8 and allowing a braking force to be generated depending on the pedal position 11. When recuperation torque 18 is present, the switching valve 19 can be opened, reducing the braking force by drawing hydraulic fluid from the brake circuit 8 to the extent that the vehicle is braked by the recuperation torque 18.

[0030] Similarly, the switching valve 19 can be opened when the brake pedal 11 is released, allowing the hydraulic fluid taken from brake circuit 8 to flow back from hydraulic circuit 15 into brake circuit 8 and thus back into the reservoir via the tandem master cylinder 10. The brake device 7 also has a control unit 20 that distributes the hydraulic fluid to the individual wheel brakes and / or controls the braking force of the individual wheel brakes.

[0031] Also shown is an optional separating component 60, which serves to separate the media used in the brake circuit 8 and the hydraulic circuit 15, thus allowing different media to be used in each. The separating component, e.g., a housing with a floating piston, naturally enables pressure transfer from one circuit to the other. The separating component 60 also serves to protect against any loss of brake fluid from the brake circuit in the event of a leak in the hydraulic circuit, i.e., it acts as a drain protection device. It is described in detail in Fig. 7 described.

[0032] Fig. Figure 3 shows an equivalent circuit diagram according to a second embodiment analogous to the one in Fig. 2 equivalent circuit diagram shown, wherein the embodiment in Fig. 2 was expanded to include additional components. Therefore, the same reference symbols denote the same components. In contrast to Fig. 2 indicates the motor vehicle according to Fig. Figure 3 shows a pressure-controlled valve assembly 21 that connects the hydraulic circuit 15 to the brake circuit 8. The valve 26 is further configured to establish a connection between the hydraulic circuit 15 and the brake circuit 8 when there is a vacuum in the hydraulic circuit 15 and to block the connection otherwise. According to this embodiment, the pressure-controlled valve assembly 21 has a pressure intensifier 22, three check valves 23-25, and a vacuum-controlled valve 26. The switching valve 19 in the hydraulic circuit 15 is optional and can be omitted. The following section will explain individual operating states of the motor vehicle, particularly with regard to the pressure-controlled valve assembly 21.

[0033] If no recuperation torque 18 is present, there is no vacuum on the hydraulic circuit 15. Consequently, the vacuum-controlled valve 26 is closed, thus blocking the lowest path 27. Paths 28 and 29 are blocked by the check valves 23 and 24, so that if the pressure in the brake circuit 8 increases, no hydraulic fluid can escape into the hydraulic circuit 15 via the connection point 14. Therefore, braking operations without a recuperation torque do not affect the bearings 2.

[0034] When a recuperation torque 18 acts on the bearings 2, pistons 16 and 17 move in opposite directions, increasing the volume of the hydraulic circuit 15. This creates a vacuum in the hydraulic circuit 15, which opens the vacuum-controlled valve 26. This allows hydraulic fluid to flow from the brake circuit 8 into the hydraulic circuit 15 via path 27, thus reducing the braking force generated by the braking device. The reduction is proportional to the recuperation torque 18, since the bearings 2 can be deflected to varying degrees depending on the recuperation torque 18. Consequently, the volume of the hydraulic circuit 15 changes depending on the recuperation torque 18, and the amount of hydraulic fluid withdrawn from the brake circuit 8 is also proportional to the recuperation torque 18.

[0035] When the braking process ends and the recuperation torque 18 ceases, the pistons 16 and 17 will return to their initial positions, and the tandem master cylinder 10 will also return to its initial position. This causes the pressure in the brake circuit 8 to drop and the pressure in the hydraulic circuit 15 to rise. As a result, the hydraulic fluid can flow back into the brake circuit 8 via path 28 through the check valve 24 and thus back into the reservoir via the supply lines 13. This is possible because there is a vacuum in the brake circuit 8 compared to the hydraulic circuit 15.

[0036] Furthermore, the pressure-controlled valve assembly can also simulate the situation in which the recuperation torque 18 drops during an ongoing braking process with recuperation. In this case, a certain brake pressure is present in the brake circuit 8 due to the braking action or the ongoing braking process. When the recuperation torque 18 ceases, the pistons 16 and 17 return to their initial positions, thus reducing the volume of the hydraulic circuit 15. This increases the pressure on the hydraulic fluid in the hydraulic circuit 15, causing the vacuum-controlled valve 26 to close or remain closed due to the overpressure in the hydraulic circuit 15. Therefore, recirculation of hydraulic fluid via path 27 is not possible. Recirculation via path 28 through the check valve 24 is also limited because, as already described, there is an increased brake pressure in the brake circuit 8.Due to the pressure intensifier 22, hydraulic fluid flowing through the check valve 25 can be fed back into the brake circuit 8 via path 29 due to the pressure increase through the check valve 23. Because of the pressure prevailing in the brake circuit 8, a small volume is sufficient to further increase the braking effect of the brake circuit 8.

[0037] The optional switching valve 19 and the optional separating component 60 are also shown here.

[0038] As previously described, the representation in the Fig. 2 and Fig. Section 3 merely represents an equivalent circuit diagram for pistons 16 and 17. The following section will illustrate the specific design possibilities using three exemplary embodiments with reference to the... Fig. 4 to 6 will be addressed. Fig. Figure 4 shows a bearing 30 according to a first embodiment. The bearing 30 has four pressure chambers 31 to 34, the four pressure chambers being operatively connected in pairs to hydraulic circuits 35 and 36. Thus, pressure chambers 32 and 34 are connected to hydraulic circuit 35, and pressure chambers 31 and 33 are connected to hydraulic circuit 36. The pressure chambers 31 to 34 are vulcanized into the bearing 30.

[0039] The bearing 30 also has a bearing core 37, which is connected to the stator of the electric machine 1. A recuperation torque 18 generated by the electric machine 1 is thus also transmitted to the bearing core 37, which is thereby moved relative to the rest of the bearing 30. An applied recuperation torque 18 causes the pressure chambers 32, 34 to be compressed and the pressure chambers 31, 33 to be expanded. This increases the pressure in the hydraulic circuit 35 or decreases the pressure in the hydraulic circuit 36. The increase in pressure in the hydraulic circuit 35 opens the pressure-controlled valve 26, so that a connection between the hydraulic circuit 36 ​​and the brake circuit 8 can be established via the connection point 14.This allows hydraulic fluid to flow from brake circuit 8 into hydraulic circuit 36, thus reducing the braking force generated by the braking device to the extent that the recuperation torque 18 causes a pressure or volume change in hydraulic circuit 36. Therefore, there is a proportionality between the recuperation torque 18 and the reduction in the braking force generated by the braking device 7.

[0040] Furthermore, the motor vehicle exhibits according to the in Fig. In the exemplary embodiment shown in Figure 4, an aperture 37 is used to filter high-frequency components. Regarding its function in relation to the other states of the motor vehicle, in particular the pressure intensifier 22 and the check valves 23 to 25, reference is made to the description in Figure 4. Fig. 2 is referenced, in which the components are also contained in an equivalent manner.

[0041] Fig. Figure 5 shows a bearing 38 according to a second embodiment. The bearing 38 has an outer bearing ring 39 that surrounds a bearing core 40. The bearing core 40 is supported relative to the outer bearing ring 39 by bearing elements 41, for example, made of an elastomer. The bearing core 40 has two bearing core parts 42, 43, namely an outer bearing core part 42 and an inner bearing core part 43. The two bearing core parts 42, 43 are rotatably movable relative to each other. The inner bearing core part 43 is connected to the stator of the electric machine 1, so that a recuperation torque 18 also acts on the inner bearing core part 43.

[0042] With an applied recuperation torque 18, the inner bearing core part 43 is in the Fig. In the situation shown in Figure 5, the bearing core is moved clockwise, so that two pressure chambers 44, 45 provided between the inner bearing core part 43 and the outer bearing core part 42 are compressed, or the volume of the pressure chambers 44, 45 is reduced when a recuperation torque 18 is applied. This increases the pressure in the hydraulic circuit 46 associated with the pressure chambers 44, 45, which is operatively connected to the two pressure chambers 44, 45. The overpressure generated in the hydraulic circuit 46 is converted into a vacuum by a pressure intensifier 47, so that hydraulic fluid can be drawn from the brake circuit 8. The dashed line 48 represents a system boundary to which the components connected, which are located in Figure 5. Fig. 2 above the corresponding dashed line 48 and in this case connect the pressure transducer 47 to the connection point 14

[0043] When the recuperation torque 18 is omitted or when a drive torque is applied, the inner bearing core part 43 is moved against a stop 49 of the outer bearing core part 42, so that the drive torque does not affect the pressure in the hydraulic circuit 46 and therefore does not lead to the removal of hydraulic fluid from the brake circuit 8.

[0044] Fig. Figure 6 shows a bearing 50, which, according to the basic structure, is similar to bearing 38. Fig. 5 corresponds to. The bearing 50 has a bearing core 51, which is also supported by a bearing outer ring 39 and corresponding bearing elements 41. The bearing core 51 has an outer bearing core part 52 and an inner bearing core part 53, which are also movable relative to each other. Four pressure chambers 54 to 57 are arranged in the bearing core 51. Pressure chambers 54 and 56 are assigned to a hydraulic circuit 58, and pressure chambers 55 and 57 to a hydraulic circuit 59, or are operatively connected to them. When a recuperation torque 18 acts on the inner bearing core part 53, it moves in the Fig. In the situation shown in Figure 6, the pressure chambers 54 and 56 are turned clockwise against the outer bearing core part 52. This expands the pressure chambers 54 and 56 and compresses the pressure chambers 55 and 57. In other words, the volume of the hydraulic circuit 59 is reduced and the volume of the hydraulic circuit 58 is increased. The change in volumes in the hydraulic circuits 58 and 59 triggers a corresponding actuation of the pressure-controlled valve 26, causing it to open and allowing hydraulic fluid to be drawn from the brake circuit 8 into the hydraulic circuit 58.

[0045] Regarding the other operating conditions of the motor vehicle, reference is made to the description of Fig. 2, Fig. Reference is made to section 3, which is applicable analogously to this embodiment. The advantages and details described for the individual embodiments can, of course, be combined, interchanged, or transferred to one another as desired.

[0046] Fig. Figure 7 shows a separation component 60, which is attached to the in Fig. 1 and Fig. This separating component 60 can be used at the two points shown. It is referred to as a "media separator" and is intended to allow the use of a different medium (e.g., hydraulic oil) in the engine bearing circuit than in the brake circuit (e.g., brake fluid). Fig. Figure 2 shows that this separation can occur before or after the valve blocks. Separating the media can be particularly advantageous because the stress on the medium in the two circuits differs significantly (see, in particular, the high heat input in the brake circuit).

[0047] The separating component 60 comprises a housing 61, which is connected to the connecting line between the brake circuit 8 and the hydraulic circuit 15. A floating piston 62 is housed in the housing 61. Depending on the pressures prevailing in the respective circuit, the piston is moved between stops 63 within the housing 61, thus transmitting the pressure.

[0048] In addition to simply separating the two circuits, the separating device also serves a protective function against the brake circuit being drained in the event of a leak in the hydraulic circuit. As described, the separating device preferably comprises a double-acting floating piston, which is subjected to pressure from both sides. This piston is acted upon by the hydraulic fluid (brake fluid) present in the brake circuit on one side and by the hydraulic fluid present in the hydraulic circuit on the other. Since the floating piston has a limited range of motion, any fluid loss from the brake circuit is also limited.

Claims

[1] Motor vehicle comprising a braking device (7) with at least one hydraulic brake circuit (8, 9) and an electric machine (1) designed for recuperation during a braking process, wherein the stator of the electric machine (1) is mounted on the body (3) by means of at least one bearing (2, 30, 38, 50) designed to absorb a reaction torque generated by the recuperation and corresponding to the recuperation torque (18), wherein a reaction torque acting on the at least one bearing (2, 30, 38, 50) can be detected, wherein a braking force generated by means of the braking device (7) can be varied depending on the recuperation torque (18) thus detected, characterized by, that the bearing (2, 30, 38, 50) has at least one pressure chamber (31 - 34, 44, 45, 54 - 57) which is connected to a hydraulic circuit (15, 35, 36, 46, 58, 59), wherein the hydraulic circuit (15, 35, 36, 46, 58, 59) is connected to the brake circuit (8), wherein a recuperation torque (18) acting on the bearing (2, 30, 38, 50) causes a change in the quantity of a hydraulic fluid in the hydraulic circuit (15, 35, 36, 46, 58, 59) and a reduction in the quantity of the hydraulic fluid in the brake circuit (8). [2] Motor vehicle according to claim 1, characterized by , that the bearing (2, 30, 38, 50) has four pressure chambers (31 - 34, 44, 45, 54 - 57) which are connected in pairs to each hydraulic circuit (15, 35, 36, 46, 58, 59). [3] Motor vehicle according to claim 2, characterized by, that the bearing (2, 30, 38, 50) has a bearing core (37, 40, 51) connected to the stator, which exerts a force on one or on at least one pressure chamber (31 - 34, 44, 45, 54 - 57) when a recuperation torque (18) is applied. [4] Motor vehicle according to claim 3, characterized by , that the bearing core (40, 51) has an inner and an outer bearing core part (42, 43, 52, 53), wherein the stator of the electric machine (1) is connected to the inner bearing core part (42, 52) and at least one pressure chamber (44, 45, 54 - 57) is provided between the inner bearing core part (42, 52) and the outer bearing core part (43, 53), the volume of which can be changed by a relative movement between the inner and outer bearing core part (42, 43, 52, 53). [5] Motor vehicle according to claim 4, characterized by, that the outer bearing core part (43, 53) has at least one stop (49) for the inner bearing core part (42, 52), wherein the inner bearing core part (42, 52) is in contact with the outer bearing core part (43, 53) at the stop (49) when an acting drive torque is generated by the electric machine (1) and introduced into the bearing (2, 38, 50) by means of the inner bearing core part (42, 52). [6] Motor vehicle according to claim 4, characterized by , that between the inner and outer bearing core part (42, 43, 52, 53) four pressure chambers (54 - 57) are formed, the volumes of which can be changed in pairs during a relative movement between the inner and outer bearing core part (42, 43, 52, 53). [7] Motor vehicle according to any one of claims 1 to 3, characterized by , that the pressure chambers (31 - 34) are vulcanized into the bearing (2, 30). [8] Motor vehicle according to any of the preceding claims, characterized by, that a locking element (19) is provided which is designed to separate the hydraulic circuit (15, 35, 36, 46, 58, 59) from the brake circuit (8). [9] Motor vehicle according to any of the preceding claims, characterized by , that the hydraulic circuit (15, 35, 36, 46, 58, 59) is connected to the brake circuit (8) by means of a pressure-controlled valve device (21) which is designed to establish a connection between the hydraulic circuit (15, 35, 36, 46, 58, 59) and the brake circuit (8) when there is negative pressure in the hydraulic circuit (15, 35, 36, 46, 58, 59). [10] Motor vehicle according to claim 9, characterized by , that the pressure-controlled valve device (21) is designed to allow a return of hydraulic fluid after the braking process and / or when the recuperation torque (18) decreases. [11] Motor vehicle according to claim 9 or 10, characterized by, that an aperture (37) is provided for filtering high-frequency components between one of the hydraulic circuits (15, 35, 36, 46, 58, 59) and the pressure-controlled valve assembly (21). [12] Motor vehicle according to any of the preceding claims, characterized by , that at least two bearings (2, 30, 38, 50) are provided, whereby the braking force can only be changed with opposing bearing movements. [13] Motor vehicle according to any of the preceding claims, characterized by , that a separating component (60) is provided by which the hydraulic fluids present in the brake circuit (8) and in the hydraulic circuit (15) are separated, and which enables pressure transmission from one hydraulic fluid to the other. [14] Motor vehicle according to claim 13, characterized by , that the separating component (60) has a floating piston which can be subjected to pressure on both sides and which is guided in a housing (61). [15] Motor vehicle according to claim 13 or 14, characterized by , that the separating component (60) serves as a drain protection for the brake circuit (8) and the hydraulic circuit (15) in the event of a leak in the other circuit.

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