WO2021005154A1

WO2021005154A1 - Pressure supply unit for a hydraulic system with at least one consumer circuit and with at least one rotary pump

Info

Publication number: WO2021005154A1
Application number: PCT/EP2020/069361
Authority: WO
Inventors: Heinz Leiber; Thomas Leiber; Anton Van Zanten
Original assignee: Ipgate Ag
Priority date: 2019-07-10
Filing date: 2020-07-09
Publication date: 2021-01-14
Also published as: DE112020003263A5; DE102019118723A1

Abstract

The invention relates to a pressure supply unit for a hydraulic system with at least one consumer circuit (BK1, BK2) and with at least one rotary pump (Pa, Pb), wherein - either a conveyance of volume in at least one conveying direction into at least one consumer circuit (BK1, BK2) is performed by means of at least one rotary pump (Pa, Pb) such that a certain required volume (V for example in [cm³]) of hydraulic medium is conveyed, in particular for a pressure build-up (Pauf), pressure dissipation (Pab) and/or an adjustment of an assembly, and/or - that at least two rotary pumps (Pa, Pb) are provided, wherein the pressure in at least one consumer circuit (BK1, BK2) can be built up and dissipated by means of corresponding electrical energization of the respective electric motor drive (Ma, Mb) of at least one of the rotary pumps (Pa, Pb).

Description

Pressure supply unit for a hydraulic system with at least one consumer circuit and with at least one rotary pump

The present invention relates to a pressure supply unit for a hyd rauliksystem with at least one consumer circuit and with at least egg ner rotary pump.

State of the art

For brake systems with increased reliability, especially in the pressure supply, redundant systems are also used with two Druckversorgungsein directions and electric motors. This is justified and necessary because the failure rates for a pressure supply device are in the range of 100ppm / year or 200 FIT. It is well known that if the pressure supply fails, the foot forces to actuate the brake are higher than normal by a factor of 5, which means that the inexperienced driver usually cannot rule this situation.

Brake systems with two pressure supply devices use either two plunger systems, the piston of which is usually adjusted by means of a spindle drive, or only one plunger system in combination with a rotary piston pump.

From DE 10 2015 221 228 A1, a brake system with two rotary piston pumps is known, which generate a brake pressure and which are both driven by an electric motor. The pressure in the individual wheel brakes is adjusted via the inlet and outlet valves. No travel simulator is used with this braking system. Each pump is assigned to exactly one brake circuit. If one pump fails, the other still functioning pump cannot take over the function of the failed pump. ie in the wheel brakes assigned to the failed pump, no brake pressure can be built up by means of the still functioning pump.

A similar brake system with two pumps is previously known from DE 102016208529 A1, each pump being assigned to a brake circuit.

DE 10 2016 211 982 A1 discloses a braking device, two Rotati onspumpen are provided, which each serve a brake circuit for Druckversor supply and are driven jointly by a drive motor. In addition, a plunger pump driven by an electric motor is provided, which supplies the two brake circuits via feed valves.

From WO 01/42069 A1 a gear pump driven by an electric motor is known to build up pressure for a brake system of a vehicle.

A method for operating a brake system of a motor vehicle is known from WO 2017/144390 A1, in which a primary brake system and a secondary brake system are provided. The primary and the secondary brake system each have rotary pumps for generating pressure. In normal operation, the brake pressure is built up by means of the primary brake system. The secondary brake system only takes over the pressure generation in the event of a malfunction in the primary brake system, which is recorded by means of a pressure recording system.

From DE 10 2013 227 089 A1 a brake system for a vehicle is known in which a motor drives two pumps, each pump being used to build up pressure in a brake circuit. From DE 10 2012 223 497 Al a braking system for a vehicle is also known in which a pump is driven by a motor, which is used to build up pressure for both brake circuits.

WO 2012/103925 A1 discloses a double internal gear pump for a brake system. The double internal gear pump is two-circuit, ie it has two separate and sealed hydraulic circuits, the two gears each assigned to a hydraulic circuit being driven by a drive motor via a common shaft. This double Internal gear pump has a large volume and additional waterproofing measures for high pressures.

For vehicles with higher safety requirements in the event of component failure, redundant concepts are required.

Object of the invention

The object of the present invention is to provide a pressure supply unit which can provide an inexpensive and simple pressure control for a hydraulic system, in particular in the form of a brake system.

This object is achieved according to the invention with a pressure supply unit with the features of claim 1.

The pressure supply unit according to the invention can be used for a wide variety of hydraulic systems with at least one consumer circuit. In a consumer circuit, in turn, several consumers can be connected to the pressure supply unit via one or more hydraulic line (s). So switching valves can be assigned to one or each consumer, by means of which the respective consumer can be disconnected from the consumer circuit. The pressure supply unit can advantageously be used for a brake system, the consumers described above being the wheel brakes.

The pressure supply unit according to the invention can have at least one rotary pump, by means of which a volume can be conveyed in at least one conveying direction in at least one consumer circuit, such that a certain required volume V, e.g. in cm ³ , of hydraulic medium, in particular for pressure build-up, pressure reduction and / or an adjustment of an aggregate of a consumer is promoted.

Alternatively or additionally, the pressure supply device according to the invention can have at least two rotary pumps, which for different maximum pressure levels Plmax and P2max and / or different pressure ranges Plmin <PI <Plmax; P2min <P2 <P2max are designed, where for the different pressure ranges in particular the condition Plmax P2max can apply. For example, one rotary pump can be designed for a pressure range greater than 120 bar and the other rotary pump for a pressure range less than or equal to 120 bar, with 120 bar corresponding to the blocking limit without fading for this vehicle. For example, the one pump, the loading of which is designed to be up to 120 bar, could be provided for building up pressure for all wheel brakes of the vehicle in multiplex mode MUX. However, as soon as a pressure higher than 120 bar is required, the other rotary pump, which is designed to be higher in the pressure range, could be switched on or it could take over the pressure regulation alone. It is also possible that the two pressure areas overlap.

In addition, a stage pump or a series connection of at least two rotary pumps can be used for one or more hydraulic circuits to achieve a higher pressure level, e.g. greater than 100 bar.

Alternatively or in addition, these can have different delivery rates when two Rotationspum are provided.

At least the drive motor for the rotary pump for volume control should be an electric motor with brushes and with semiconductors, e.g. MOSFET control for flow and return. The drive motor for the pump for the higher pressure range can be a brushless motor. In a preferred embodiment, both drive motors are electric motors with brushes and with semiconductors, e.g. MOSFET control for flow and return, so that pressure build-up and pressure reduction is possible with both rotary pumps.

The pressure supply unit described above is inexpensive, simple and has a small structural volume.

For the purposes of the invention, a rotary pump is understood to mean one of the pumps listed below:

1. Rotary piston pumps, such as rotary piston pumps, rotary vane pumps, rotary piston pumps, vane pumps, gerotor or gear pumps; 2. Radial pump, in particular in the form of a radial piston pump;

3. Flow pump, in particular in the form of a centrifugal pump;

4. Positive displacement pump with rotating rotor, which forms self-contained volumes with a wall surrounding it, in which the medium is conveyed by the rotation;

A rotary pump in the sense of the invention is in particular not understood to include a reciprocating piston pump in which the piston executes a straight (translational) movement.

The rotary pump according to the invention preferably has an electric motor drive, the rotor of which, for example, forms or drives the at least one gear wheel of a gear pump or the impeller of a centrifugal pump.

In the context of the invention, a 1-circuit rotary pump is understood to mean a rotary pump with only one hydraulic circuit, i.e. it has only one input and one output, a rotor. The 1-circuit rotary pump, on the other hand, can be single-stage or multi-stage, with the individual stages being arranged in series so that, for example, the first stage builds up a first pressure level and the following stage a higher pressure level.

In the context of the invention, a multi-circuit rotary pump is understood to mean a rotary pump which has a plurality of hydraulically separated and sealed hydraulic circuits, this having or being able to have only one electric drive for all hydraulic circuits.

The pressure supply unit according to the invention can, for example, advantageously replace a motor-driven piston-cylinder unit of known brake systems, which often have expensive spindle drives or ball screw drives. Such expensive screw drives are omitted in the pressure supply unit according to the invention, which makes it small and inexpensive.

The above-described volume delivery can advantageously take place by means of a volume control in such a way that the proportionality between Rotation angle Df of the rotor of the rotary pump and the volume V promoted in the process, the necessary rotation angle Df for a required volume V _so n of hydraulic medium is calculated and then the rotor or the pump element is adjusted by the calculated rotation angle by means of the drive of the rotary pump.

Likewise, the volume control can additionally or alternatively take into account the time At within which the required volume V _so n of hydraulic medium is to be delivered, the speed of the rotor of the rotary pump v _{M being} adapted to the available time At. In this way, a volume of hydraulic fluid to be conveyed can also be conveyed precisely.

By varying the motor current, the delivery rate and the delivery direction can be determined. The direction of rotation or the conveying direction can be actively influenced by the direction of the motor current. It is also possible that the direction of flow of the hydraulic medium through the rotary pump changes simply by lowering the motor current, provided that a correspondingly high pressure is still included in a hydraulic circuit.

Advantageously, the pressure volume characteristic (PV characteristic) of one or both brake circuits and / or the respective wheel brake can also be used for quantitative pressure control. The PV characteristic curve can be determined before the vehicle starts.

The pressure supply unit according to the invention can advantageously have at least two pressure supply devices, each pressure supply device having at least one rotary pump and a drive for driving the respective rotary pump. It is also possible for the pressure supply unit according to the invention to have only a single pressure supply device, this pressure supply unit either connecting at least two hydraulically series-connected rotary pumps, in particular in the form of a two-stage or multi-stage rotary pump, or two series circuits of at least two each hydraulically connected in series Has rotary pumps, in the latter case the rotary pumps connected in series are driven by a single drive or each series connection is driven by its own drive.

The rotary pump can also be a multi-circuit rotary pump which has several hydraulic circuits that are separate and sealed from one another.

The rotary pump, at least for volume control, can be designed in one or more stages, with several stages being arranged hydraulically in series.

In the case of a multi-stage design of the rotary pump, both pump stages can be driven by one and the same drive and e.g. supply one or more hydraulic circuits.

The rotary pump not intended for volume control can be a simple continuously conveying pump, in particular in the form of a piston pump, vane pump, rotary vane pump or gear pump. This generates a certain pressure depending on the drive power and the motor current. The pressure can be regulated by current regulation. However, it is also possible for valves controlled by pulse width modulation to regulate the pressure provided by the continuously conveying pump for the consumer or consumers.

If the pressure supply unit has at least two pressure supply devices or rotary pumps, it can supply a corresponding number of consumer circuits, in particular in the form of brake circuits, with hydraulic medium and corresponding pressure. A rotary pump can, for example, be assigned to each consumer circuit.

In order to provide a particularly fail-safe pressure supply unit, a hydraulic connection line can be provided in a hydraulic system with two consumer circuits, with at least one switchable valve, in particular two switchable bypass valves connected in series, for the optional opening and closing of the connection line, to increase safety. This advantageously results in the possibility that either in the event of a failure of a pressure supply device or rotation Onspumpe the other still functioning Druckversorgungseinrich device or rotary pump takes over the function of the failed one, or both pumps interact via the hydraulic connecting line to build up pressure in one or both brake circuits. The latter case is used advantageously to enable the pressure build-up within a very short time (time to lock = TTL). The individual pumps can be made smaller.

Advantageously, when two rotary pumps are provided, one rotary pump can be designed for a lower maximum pressure Plmax than the other rotary pump with P2max. If higher pressures than Plmax are required, either the other pump with its higher maximum pressure P2max can be switched on or the pressure build-up can be controlled by yourself. If the pump with the higher maximum pressure fails, a maximum pressure of Plmax can still be provided .

However, it is also possible, when two rotary pumps are provided that have the same maximum pressure, to connect the two rotary pumps in series by means of suitable valves in order to form a two-stage pump, with the delivery pressure of both pumps then being added. At least one non-return valve and a switching valve connected in parallel must then be provided here if necessary.

Different maximum pressures also result when the electrical drive power of the drive of one rotary pump is greater than the electrical drive power of the drive of the other rotary pump.

The pressure supply unit can also be used advantageously for the hydraulic system of an electric vehicle, with only one pressure supply device having to be provided, which in particular only serves to generate braking pressure in a brake circuit.

If present, both rotary pumps can advantageously be arranged in one housing. It is also possible that the axes of the rotary pumps are aligned parallel to one another and the axes are arranged in particular parallel or perpendicular to the axis of the master brake cylinder, if this is available. The master cylinder can either be arranged in a separate housing or together with the rotary pumps in a common housing.

In the pump housing, the solenoid valves, in particular for all control and regulation functions (ESP, ABS), can also be arranged in one housing. The electronic control and regulation unit ECU can be arranged in a separate ECU housing. The sensors can be arranged either in the ECU housing or on it. The ECU itself can be partially or fully redundant.

The brake system according to the invention can have a single or tandem master brake cylinder which can be actuated by a brake pedal. Alternatively, an electric pedal or just an actuation switch, e.g. for level 5 in automatically driving vehicles (AD), can be provided.

In the case of a non-redundant on-board network, an auxiliary on-board network, e.g. with U-caps, can be used for some braking operations, so that if the on-board network fails while the vehicle is in motion and thus also when the vehicle is driven, braking is still possible until the vehicle comes to a stop.

With the aforementioned features, a 1-box solution with two pressure supply devices can advantageously be implemented cost-effectively and smaller than a conventional 1-box solution with plunger pistons.

At least one valve can be provided at the outlet of the pressure supply device, which valve is or are used for pressure regulation and prevents or prevents a backflow of hydraulic medium into the storage container.

The use of the pressure supply unit according to the invention in various possible embodiments of hydraulic systems is explained in more detail below with reference to drawings.

Show it : Fig. 1: A first possible embodiment of an inventive

Hydraulic system with a fail-safe valve arrangement for connecting both brake circuits, a master cylinder with actuating device and two pressure supply devices with electronic control and regulating device as a so-called integrated 1-box system;

Fig. La: a second possible embodiment of an inventive

Fig. Lb: a third possible embodiment of an inventive

Fig. Lc: a fourth possible embodiment of an inventive

Hydraulic system with a fail-safe valve arrangement for connecting both brake circuits, a master cylinder with actuation device and with a pressure supply device with electronic control and regulation device as a so-called integrated 1-box system;

FIG. 1d: a further development of the fourth embodiment according to FIG. 1c with two two-stage pump arrangements;

Fig. 1e: modification of the embodiment shown in Fig. 1b with only one bypass valve BPI;

FIG. 1f: modification of the embodiment shown in FIG. 1b with an additional central outlet valve ZAV2; Fig. 2: A fifth possible embodiment of an inventive

Hydraulic system with a master cylinder with actuation device and with a pressure supply device with electronic control and regulation device;

3 and 3a: first possible embodiment of an arrangement of the individual components, in particular the housing of the pressure supply unit in two views;

3b: perspective view of the pressure supply unit according to the figures

3 and 3a;

4 and 4a: a second possible embodiment of an arrangement of the individual components, in particular the housing of the pressure supply unit, in two views;

4b: perspective view of the pressure supply unit according to the figures

4 and 4a.

Figure 1 shows the basic elements of a controllable brake system for Fahrzeu ge, consisting of the master brake cylinder SHZ with path simulator WS and storage container VB and two pressure supply devices DV1 and DV2. The pressure supply device DV1 in turn has the rotary pump Pa, the brushless direct current motor Ma, the rotor angle encoder WGa of the motor Ma with electrical connection Wea, the winding connection 3a of the direct current motor Ma and the shunt 4a of the direct current motor Ma. The pressure supply device DV2 has the rotary pump Pb, the direct current motor Mb, the winding connection 3b of the direct current motor Mb and the shunt 4b of the direct current motor Mb. Both rotary pumps Pa and Pb of the two pressure supply devices DV1 and DV2 are, in particular single-circuit, rotary pumps. The rotary pump Pa can preferably be a gear pump. The rotary pump Pa of the pressure supply device DV1 is preferably driven by a brushless direct current motor (EC motor) Ma, while the rotary pump Pb of the pressure supply device device DV2 is driven by a direct current motor Mb, preferably with brushes. The rotary pump Pb can be a simple 1-circuit gear pump or a 1-circuit piston pump.

The pressure supply device DV1 is designed for the usual locking pressure, with locking pressure being understood as the minimum pressure at which all vehicle wheels lock. A blocking pressure of 120 bar is usual for most vehicles. Overheated brakes (fading) or overloading the vehicle can cause the locking pressure to rise so that the maximum pressure that can be achieved with the pressure supply device DV1, e.g. 120 bar, is not sufficient to lock all vehicle wheels. For this reason, the pressure supply device DV2 is designed for higher pressures than the pressure supply device DV1, e.g. for 200 bar. Both pressure supply devices DV1 and DV2 can individually or together generate the wheel brake cylinder pressure, which by means of suitable valve positions of a valve circuit to the wheel brake cylinders RZ1, RZ2, RZ3, RZ4, z. B. with ABS, is set or regulated in the respective wheel brake cylinders. In principle, this is state of the art. The pressure supply unit according to the invention for a hydraulic system or brake system should, however, have a high level of error security, e.g. for highly automated (HAD) or fully automated driving (FAD). For this purpose, all failure-relevant components should be taken into account, such as B. valves, sensors, seals, motors and brake circuits. The following components or hydraulic connections should therefore advantageously be designed to be fail-safe:

(1) Connection from the one provided for the first brake circuit BK1

Pressure supply device DV1 to the second brake circuit BK2;

(2) Connection from the one provided for the second brake circuit BK2

Pressure supply device DV2 to the first brake circuit BK1;

(3) Connection from the pressure chamber of the master brake cylinder SHZ via the

Switching valve FV to the brake circuits BK1, BK2 via the bypass valves BPI and BP2;

(4) Connection of switching valve PD1 and bypass valve BPI to the wheel

brake cylinders RZ1 and RZ2 via the respective switching valves SV assigned to the wheel brakes (5) Connection of bypass valve BP2 to the wheel brake cylinders RZ3 and

RZ4 via the respective switching valves assigned to the wheel brakes

SV;

(6) Connection from a brake circuit BK1, BK2 to the storage container

VB;

(7) Connections between brake circuits BK1, BK2 to the Radbremszy alleviate RZ.

These hydraulic connections with possible failure errors of the individual components are described below.

The pressure supply device DV1 acts from the brake circuit BK1 into the brake circuit BK2 via the hydraulic lines 1, 2 and 5 and via the switching valves SV to the wheel brake cylinders RZ1, RZ2, RZ3, RZ4. In the prior art, only a single bypass valve is used for this purpose. A failure of the single bypass valve can lead to a total failure of the brake if there is a sleeping error in another valve. The term "sleeping fault" is understood to mean a single fault which has no effect on braking, but which can have an effect in combination with another fault on braking. The invention therefore provides two redundant bypass valves BPI and BP2 to make the connection to the brake circuit BK2 from the first pressure supply device DV1.Sleeping faults in the bypass valves BPI and BP2 are detected by means of pressure transducers DG by closing the bypass valves BPI and BP2 alternately over a short period of time during a pressure change by the pressure supply device DV1 during the

During the closing phase of bypass valve BPI or bypass valve BP2, the pressure in brake circuit BK2 must remain constant. If the first pressure supply device DV1 fails, for example if the DC motor Ma fails, feedback on the brake circuit BK2 via the two redundant bypass valves BPI, BP2 and the switching valve PD1 is prevented. The bypass valves BPI and BP2 are preferably normally open valves so that if the pressure supply devices DV1 and DV2 fail, the master cylinder SHZ can act on both brake circuits BK1 and BK2 via the open switching valve FV. If the pressure in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4 is to be reduced, this can be done by opening the switching valves ZAV or FV. The two bypass valves BPI and BP2 can open continuously without their own electrical control, due to the differential pressure acting via these bypass valves BPI and BP2, which ensures that a pressure reduction is possible in the event of a fault, e.g. failure of the control electronics of the two bypass valves BPI and BP2 and eg locking of the wheels is reliably prevented.

The central outlet valve ZAV can either be connected with its one connection via the line V _Z AV to the line VL by means of the line connection K or else be connected directly to the first brake circuit BK1 via the alternative line V'ZAV. The latter has the advantage that in the event of a double fault in the valves ZAV and FV, the master brake cylinder SHZ does not also fail.

The pressure supply device DV2 acts accordingly in the second brake circuit BK2 via the hydraulic lines 2 and 5 and via the switching valves SV to the wheel brake cylinders RZ3 and RZ4, and via the bypass valves BP2 and BPI into the hydraulic line 4 and from there via the switching valves SV to the wheel brake cylinders RZ1 and RZ2. A failure of the brake circuit BK1, e.g. due to a leak in a seal in one of the wheel brake cylinders RZ1, RZ2, can be detected by diagnosis using one of the switching valves SV in brake circuit BK1, in which case the bypass valves BPI and BP2 are closed, resulting in a failure of the pressure supply device DV2 is prevented and pressure regulation or control is still possible by means of the pressure supply device DV2 in the brake circuit BK2. A failure of the brake circuit BK2, e.g. due to a leak in a seal in a wheel brake cylinder of the RZ3 or RZ4, can be detected by diagnosis using one of the switching valves SV in the brake circuit BK2, with the bypass valves BPI and BP2 then also being closed, resulting in a failure of the pressure supply device device DV1 is prevented and pressure regulation or control is still possible by means of the pressure supply device DV1 in the brake circuit BK1. In this context, leaks in all valves, e.g. SV, BPI, BP2, are to be regarded as dormant errors from a safety-critical point of view. The hydraulic medium flowing through the valves contains dirt particles which can prevent the respective valve from closing and the valves thus become leaky. In the present In the same case, for example, if a seal on a wheel brake cylinder RZ1 or RZ2 fails and the associated switching valve SV is dormant, the brake circuit BK1 may fail, but the brake circuit BK2 is protected by the interconnection of the two bypass valves BPI and BP2. Similarly, if a seal on a wheel brake cylinder RZ3 or RZ4 fails and the associated switching valve SV is dormant, brake circuit BK2 can fail, but brake circuit BK1 is also secured by interposing the two bypass valves BPI and BP2. There should be a triple fault here, ie both bypass valves BPI and BP2 would also have to fail so that there is a total failure of both brake circuits BK1 and BK2. Each of the two brake circuits BK1 and BK2 is thus reliably protected against double faults and prevents total brake failure. Security against double faults, when dormant faults can occur, is a crucial security feature for HAD and FAD. This also includes maintaining the pressure supply or the brake booster in the event of a brake circuit failure.

The pressure supply device DV2 can support the other pressure supply device DV1 and / or perform the ABS function in the event of a rapid pressure build-up or pressure build-up above e.g. 120 bar and / or take over its function if the other pressure supply device DV1 fails. The pressure can be reduced by means of a rotary pump Pa, Pb or, if available, alternatively or simultaneously by means of at least one outlet valve ZAV, AVI, AV2.

It is also possible that the pressure supply device DV1 takes over the pressure build-up for pressure ranges less than or equal to 120 bar and for the ABS function. The pressure reduction in a brake circuit takes place by reversing the direction of rotation of the rotary pump Pa. If the pressure supply device DV2 fails, if the pressure supply device DV1 is only designed for a maximum pressure of e.g. 120 bar, only this maximum pressure of e.g. 120 bar is available for both brake circuits BK1 and BK2.

With closed bypass valves BPI and / or BP2, the two pressure supply devices DV1 and DV2 in their brake circuits BK1 and BK2 adjust or adjust the pressure independently of each other. Here, too, the pressure reduction can take place via the rotary pump Pa. However, if there are additional outlet valves ZAV, AVI, AV2, the pressure in one or more wheel brakes can also be reduced via these. A simultaneous pressure reduction by means of a rotary pump, e.g. Pa, e.g. in the wheel brake RZ1 by reversing the direction of rotation of the rotary pump Pa, whereby the pressure is simultaneously reduced e.g. in the wheel brake RZ3 via the rotary pump Pb or via an outlet valve AV2, ZAV .

The pedal movement is measured via redundant pedal travel sensors PS, which at the same time act on a KWS measuring element (force-travel sensor) according to WO2012 / 059175 A1. The signals from the pedal travel sensors are used to control the pressure supply device DV1, the rotary pump Pa causing the volume flow in the hydraulic line 1 in the brake circuit BK1 and via the redundant bypass valves BPI and BP2 in the brake circuit BK2. The pressure supply device DV1 can be designed so that it is only up to the blocking pressure z. B. 120 bar acts. For higher pressures, the pressure supply device DV2 then supplies volume in the brake circuit BK2 and via the redundant bypass valves BPI and BP2, and when the switching valve PD1 is closed, in the brake circuit BK1. The pressure supply device DV2 can be a continuously delivering pump. If the brake system is badly vented or if there is a development of vapor bubbles with a higher volume requirement, this is recorded via the known pressure volume characteristic (PV characteristic) of the brake, which means that the pressure supply device DV1 has to deliver more volume in order to maintain a certain pressure in the wheel brake cylinders RZ1 , RZ2, RZ3 and RZ4. When the pedal is actuated, the Kol ben Ko is moved, which acts on the known path simulator WS via the pressure proportional to the pedal force and thus determines the pedal characteristics. The path simulator WS can usually be switched off via a valve, in particular in the fall-back level if the pressure supply devices DV1 and DV2 have failed. In the case of redundant pressure supply devices, this is in principle no longer relevant due to the very low probability of failure. The master brake cylinder SHZ can be connected to the brake circuits BK1 or BK2 via the line 3, the switching valve FV being arranged in the hydraulic line 3 for closing the same. This connection is only effective in the fall-back level, ie when both pressure supply devices DV1 and DV2 have failed. If the hydraulic line 3 is connected to the connecting line VLa of the two bypass valves BPI and BP2, the two bypass valves BPI and BP2 form a further redundancy. A common connection from the switching valve FV directly into one of the two brake circuits BK1, BK2 would result in a leaky switching valve FV that the brake circuit and thus the pressure supply act on the SHZ piston Ko, which must immediately switch off the pressure supply .

A failure of the brake circuit BK2 can occur, e.g. when using a 1-circuit gear pump as a rotary pump Pb, due to a leak in the non-return valve RV1. The failure of the pressure supply device DV2 can be prevented here by a redundant check valve RV2. A hydraulic connection between the two non-return valves RV1 and RV2 to the storage container VB with the throttle Dr with a small flow rate enables diagnosis, e.g. B. via measurable pressure drop.

A central outlet valve ZAV is required for ABS control or for pressure reduction with the second Druckver supply device DV2. The volume flow also goes through the bypass valves BPI or BP2, so that a leaky ZAV is not critical for normal operation, since if the central outlet valve ZAV leaks, the pressure control in BK1 via the pressure supply device DV1 and the pressure control in BK2 via the pressure supply device DV2 for the pressure build-up takes place. The pressure reduction in the brake circuit BK2 can continue to take place via the bypass valve BP2 even if the outlet valve ZAV is leaking. In addition, the fault, even while asleep, is recognized by the ZAV through a change in pressure or increased volume delivery of the pressure supply device DV1.

With normal braking up to approx. 120 bar, the pressure supply device DV1 acts via open bypass valves BPI and BP2 in both brake circuits BK1 and BK2. For extreme safety requirements, a redundant configuration can also be Let valve ZAVr be installed in the hydraulic line 6 from the central outlet valve ZA V to the storage container VB.

The ABS function via multiplex operation MUX and the pressure supply device DV1 takes place as described in WO 2006/111393 A1. However, in the case of the rotary pump, in particular in the form of a gear pump, the direction of rotation is reversed in order to reduce the pressure. Extended multiplex functions result from a central outlet valve ZAV. If a pressure reduction Pab in the other brake circuit BK2 is necessary at the same time as the pressure Pauf builds up in the brake circuit BK1, this pressure reduction takes place via the central outlet valve ZAV with the bypass valve BPI closed at the same time. As a result, the multiplex operation MUX is only loaded by two wheel brake cylinders RZ1 and RZ2 in the brake circuit BK1. For example, a pressure build-up Pauf in wheel brake cylinder RZ1 and a pressure decrease Pab in wheel brake cylinder RZ2 of brake circuit BK1 cannot take place at the same time. Alternatively, an outlet valve AVI or AV2 in the respective brake circuit BK1 or BK2 can also be used to reduce pressure Pab to relieve the multiplex operation MUX. On the one hand, the outlet valve AVI or AV2 can either be arranged or connected between a switching valve SV and a bypass valve BPI or BP2 or between the wheel brake cylinder and the associated switching valve SV, and on the other hand, can be connected to the storage container VB so that a direct pressure reduction Pab can take place via the outlet valve to the storage container VB. This is particularly useful for reducing the pressure Pab in the Radbremszy of the front wheels. The central outlet valve ZAV is not required with this alternative.

The ABS function by means of the second pressure supply device DV2 is slightly restricted in this case; in particular, no pressure build-up Pauf in one wheel brake cylinder is possible or provided during a pressure reduction Pab in another wheel brake cylinder. A fully individual ABS control is still possible. The infrequent use of the pressure supply device DV2 at pressures greater than 120 bar and if the first pressure supply device DV1 fails should be taken into account. Typical for the above-mentioned multiplex operation MUX in ABS operation, for example, is that the pressure control with the pressure supply device DV1 via the volume metering, which is calculated using the rotor rotation or the rotor rotation angle of the rotary pump, which is measured using the rotor angle sensor WGa. The pressure-volume characteristic of the brake (PV characteristic) can also be taken into account here.

When using a simple eccentric piston pump as a rotary pump Pb in the pressure supply device DV2, this cannot be done via the piston movement, but via the delivery time, which is proportional to the volume delivered with additional speed measurement and, if necessary, pressure measurement. This means that a volume measurement is also required for the Pressure can be built up by means of the pressure supply device DV2. A serial and non-simultaneous pressure build-up Pauf in the individual wheel brake cylinders is advantageous here.

The valve dimensioning of the back pressure at the valve must be taken into account, especially with the bypass valves BPI and BP2 with rapid pressure build-up Pauf in the brake circuits. The back pressure at the bypass valves BPI and BP2 acts as a pressure difference between the brake circuits BK1 and BK2. This can be reduced considerably if both pressure supply devices DV1 and DV2 are switched on in this operating state. A 1-circuit gear pump can also be used with the pressure supply device DV2 instead of a piston pump. The pressure reduction Pab and pressure build-up Pauf can also take place here via the gear pump. For this purpose, instead of the check valves RV1 and RV2, a switching valve MV, not shown, is required in the return line to the storage container VB. A full multiplex operation MUX is thus also possible with the second pressure supply device DV2.

The control and regulating device ECU in housing B is part of the total th system and packaging. A redundant or partially redundant ECU is necessary for a fail-safe function. This partially redundant ECU can also be used for certain functions in addition to the redundant ECU. In any case, the valves are or should be redundant via separate ones Valve driver and circuit breaker are driven, which switches off a failed valve driver.

A redundant on-board power supply connection BN1 or BN2, or an auxiliary on-board power supply connection with e.g. U-caps BN2 ', if the redundant on-board power supply connection BN2 is not available, is also required for redundancy of the control and regulation device ECU in housing B. A connection with 48V can also be used to connect the motors. The advantage of 48V is higher dynamics. If the motor from the pressure supply device DV1 fails at 48V, emergency operation at 12V with approximately 50% power with reduced dynamics is given, which advantageously results in cost savings. For this purpose, the motor must be designed for e.g. 24V.

A pressure transducer DG is preferably used in brake circuit BK2, possibly also in BK1 (as shown in dashed lines). If the pressure transducer fails, the pressure can be regulated by measuring the current in the motors and controlling the angle of the rotors, in particular in the form of gears, using the pressure-volume characteristic (PV characteristic).

In the hydraulic line 2 of the pressure supply device DV2, a pressure relief valve ÜV can also be arranged to protect the drive, which opens e.g. at approx. 120 bar.

FIG. 1 a shows a second possible embodiment of a hydraulic system according to the invention, which is based on that shown in FIG. The difference to the first possible embodiment shown in FIG. 1 is the configuration of the pressure supply device DV2. From the axis Ab of the direct current motor Mb two rotary pumps Pb and Pbl, insbesonde re in the form of gear pumps, instead of the individual rotary pump Pb ge according to FIG. 1, driven. The rotary pumps Pb and Pbl are hydraulically connected in series. The input side of the rotary pump Pb is connected directly to the storage container VB via hydraulic line HL1. The output side of the rotary pump Pb is directly connected to the input side of the rotary pump Pbl. The hydraulic line 2 connects the output side of the rotary pump Pbl with the brake circuit BK2. In the hydraulic line 2 a normally closed switching valve PD2 is introduced, which when energized of the DC motor Mb is opened. When the pressure in the hydraulic line 2 should no longer be increased, the switching valve PD2 is closed so that no volume can flow from hydraulic line 2 through the rotary pumps Pb and Pbl and through the hydraulic line HL1 back into the storage container VB. Likewise, if the rotary pumps Pb and Pbl fail or leak, or if the DC motor Mb fails, the switching valve PD2 is closed.

The series connection of the rotary pumps Pb and Pbl, which are in particular gear pumps, forms a two-stage pump, by means of which the pressure supply device DV2 can build up higher pressures in the hydraulic line 2 than when using a single rotary pump Pb with the same volume delivery. If both rotary pumps Pb and Pbl are designed for a maximum pressure of e.g. 100 bar, then by connecting the two rotary pumps Pb and Pbl in series, a maximum pressure can be built up in hydraulic line 2, which corresponds roughly to the sum of the two maximum pressures 100 bar + 100 bar = 200 bar.

Figure lb shows a third possible embodiment of a hydraulic system according to the invention Shen, which builds on the hydraulic system shown in FIG. The difference to the hydraulic system shown in Fig. 1 is the design of the pressure supply device DV2. The pressure supply device DV2 consists of the rotary pump Pb, which is in particular a gear pump, a brushless direct current motor Mb to drive the rotary pump Pb, the rotor angle encoder WGb of the direct current motor Mb with electrical connection Web, the winding connection 3b of the direct current motor Mb and the shunt 4b of the direct current motor Mb. As with the pressure supply device DV1, the rotary pump Pb and the direct current motor Mb is designed for the blocking pressure, for example 120bar. This interpretation of the pressure supply device DV2 makes it possible to increase the brake pressure in brake circuit BK2 and in the Radbremszy RZ3 and RZ4 with the rotary pump Pb and also reduce it with the rotary pump Pb when the switching valve PD2 is open. To reduce the brake pressure in the wheel brake cylinders RZ3 and RZ4 and in the brake circuit BK2, the motor torque of the direct current motor Mb is reduced, whereby the direction of rotation of the Rotary pump Pb is reversed due to the pressure still prevailing in the brake circuit BK2, compared to the direction of rotation of the rotary pump Pb when the pressure increases. Hydraulic medium then flows from the Radbremszylin countries RZ3 and RZ4, through the associated switching valves SV, the Hydrauliklei device 5, the open switching valve PD2, the rotary pump Pb and the hydraulic line HL1 back into the reservoir VB.

The rotary pump Pa of the pressure supply device DV1 can, as already described with reference to FIG. 1, suck in hydraulic medium through the hydraulic lines 7, 7a and HL2 from the storage container VB to increase the brake pressure in the wheel brake cylinders RZ1 and RZ2. The difference from the embodiment according to FIG. 1 is that a check valve RV3 is arranged in the hydraulic line 7, 7a. The check valve RV3 has a large cross section, so that the throttling losses via the check valve RV3 when hydraulic medium is sucked in from the storage container VB are low. As already described in Fig. 1, the brake pressure in the wheel brake cylinders RZ1 and RZ2 can be reduced by means of the rotary pump Pa when the switching valve PD1 and the associated switching valves SV are open, in which + e the motor torque is reduced by undercurrent to the DC motor Ma, whereby the direction of rotation of the rotary pump Pa is reversed due to the pressure in the wheel brakes, compared to the direction of rotation of the rotary pump Pa when the pressure is built up. However, since the check valve RV3 blocks when the pressure is reduced, a further normally closed switching valve PD4 is necessary, which is arranged parallel to the check valve RV3 and which is opened when the pressure is reduced. When the pressure in the wheel brake cylinders RZ1 and RZ2 is reduced, hydraulic media then flows from the wheel brake cylinders RZ1 and RZ2, through the open associated switching valves SV, the hydraulic lines 4 and 1, the open switching valve PD1, the rotary pump Pa, the hydraulic lines 7, 7a, the open switching valve PD4 and the hydraulic line HL2 back into the storage container VB. The higher throttling losses of the switching valve PD4 compared to the throttling losses of the check valve RV3 do not play a significant role in the pressure reduction gradient. The input side of the rotary pump Pa is connected to the output side of the rotary pump Pb via a hydraulic line 6. The hydraulic lines 6 and 7 are connected to one another at point A. In this Hydrauliklei device 6 a normally closed switching valve PD3 is included. If the braking is initiated with the aid of the pressure supply device DV1, and if a high pressure of 160 bar, for example, is generated in the wheel brake cylinders RZ1, RZ2,

RZ3 and RZ4 required, which is higher than the maximum pressure of the Druckversor supply device DV1, for example 120bar, so with closed Schaltventi len PD2 and PD4 and open switching valve PD3, the Druckversorgungsein direction DV2 is switched on by the DC motor Mb is energized, whereby a Series connection of the pressure supply devices DV1 and DV2 results. Thus, the rotary pump Pa is acted upon on the input side by the actuating device DV1, through the hydraulic line 6, the open switching valve PD3 and the hydraulic line 7, with the output pressure of the rotary pump Pb, with the effect that the output pressure of the rotary pump Pa of the pressure supply device DV1 is the sum of the Differential pressures (rotary pump input side to output side), the rotary pump Pa from the pressure supply device DV1, for example 120bar, and the rotary pump Pb from the pressure supply device DV2, is, for example 120bar + differential pressure of the rotary pump Pb. With the bypass valves BPI and BP2 open, this sum value can be compared with the value of the pressure transducer DG, and the motor current of the direct current motor Mb can be set so that the measured pressure of the pressure transducer DG equals the required pressure of 160, for example, with the differential pressure of the rotary pump Pb is then 40bar in this example.

If the brake pressure in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4 is to be reduced from e.g. 160 bar, to e.g. 100 bar, then the motor torque of the DC motor Mb is reduced by insufficient current or, if the pressure is to be reduced very quickly, the sign is reversed, while the Motor torque of the direct current motor Ma is initially held at the maximum value, whereby the direction of rotation of the rotary pumps Pa and Pb is reversed. Hydraulic medium then flows out of the wheel brake cylinders RZ1 and RZ2, through the associated switching valves SV, the hydraulic lines 4 and 1, the opened switching valve PD1, the rotary pump Pa, the opened switching valve PD3, the gear pump Pb and the hydraulic line HL1 back into the storage container VB. Hydraulic medium also flows from the Radbremszy alleviate RZ3 and RZ4 through the associated switching valves SV, the Hydrauliklei device 5, the open bypass valves BPI and BP2, hydraulic line 1, the open switching valve PD1, the rotary pump Pa, the switching valve PD3, the rotary pump Pb and the hydraulic line HL1 back into the storage container VB. If the pressure has dropped to 120bar, or the motor current of the DC motor Mb has been reduced to 0 amps, then the pressure supply device DV2 is switched off and the switching valve PD3 is closed to further reduce the pressure in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4 then takes place, as already described, when the switching valve PD4 is open via the control of the pressure supply device DV1.

Since both pressure supply devices DV1 and DV2 can both increase and reduce the pressure by reversing the direction of rotation of the rotary pumps Pa and Pb, multiplex operation MUX is also possible for both pressure supply devices DV1 and DV2 without using the outlet valves ZAV, AVI, AV2.

As an alternative to multiplex operation, the pressure reduction Pab can also take place via the control of the switching valves SV. For example, switching valves SV controlled by pulse width modulation can be used to set or regulate different flow rates for the individual switching valves. The pressure reduction can advantageously take place via a central outlet valve ZAV. This enables an individual pressure reduction simultaneously in the individual wheel brakes, which is disadvantageously not possible in pure multiplex operation, in which the pressure reduction in the individual wheel brakes occurs one after the other.

The ABS function can take place, for example, in multiplex mode MUX and the pressure supply device DV1, as described in WO 2006/111393 A1. Via the pressure supply device DV1, all Radbremszy cylinders are then regulated with the multiplex mode MUX in pressure, as already shown in Fig. 1 is described. The same applies to the pressure supply device DV2. The back pressure of the bypass valves BPI and BP2 acts as a pressure difference between the brake circuits BK1 and BK2. This can be considerably reduced if both pressure supply devices DV1 and DV2 are switched on, as already described - parallel operation of the two pressure supply devices DV1 and DV2. Furthermore, the pressure reduction Pab and in particular the multiplex operation MUX can be relieved by the parallel operation of the pressure supply devices DV1 and DV2. If pressure build-up Pauf in brake circuit BK1 requires a pressure reduction Pab in the other brake circuit BK2 at the same time, this pressure decrease takes place via the opening of switching valve PD2 with bypass valve BP2 closed at the same time, and by reversing the direction of rotation of gear pump Pb. As a result, the multiplex operation MUX in the pressure supply device DV1 is only loaded by two wheel brake cylinders RZ1 and RZ2 in the brake circuit BK1. For example, a pressure build-up Pauf in the wheel brake cylinder RZ1 and a pressure decrease Pab in the wheel brake cylinder RZ2 of the brake circuit BK1 cannot then take place at the same time.

If the pressure build-up Pauf in the brake circuit BK1 requires a pressure reduction Pab in the other brake circuit BK2 at the same time, this pressure reduction can also take place by opening the bypass valve BP2 with the bypass valve BPI and switching valve PD2 closed at the same time, and by opening the central outlet valve ZAV. Alternatively, an outlet valve AVI or AV2 in the respective brake circuit BK1 or BK2 can also be used to reduce pressure Pab to relieve the multiplex operation MUX. On the one hand, the outlet valve AVI or AV2 can either be arranged or connected between a switching valve SV and a bypass valve BPI or BP2 or between the wheel brake cylinder RZ1, RZ2, RZ3 or RZ4 and the associated switching valve SV and, on the other hand, connected to the storage container VB so that a direct pressure reduction Pab can take place via the outlet valve AVI or AV2 to the storage container VB. This is particularly useful for the undelayed pressure reduction Pab in the wheel brake cylinders of the front wheels.

The central outlet valve ZAV is not required with this alternative.

Typical for the above-mentioned MUX multiplex operation with ABS, for example, is pressure control also with the pressure supply device DV2, via volume metering which is calculated by means of the rotor or gear movement or the rotor angle of the rotary pump Pb, which is measured by means of the rotor angle encoder WGb, also taking into account the pressure-volume characteristic of the brake (PV characteristic). Volume measurement or volume control for the pressure build-up and pressure reduction via the pressure supply device DV2 is thus also possible.

If the maximum pressure of the two pressure supply devices DV1 and DV2, for example 120 bar each, is not sufficient to achieve the locking pressure of 160 bar in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4, the pressure supply devices DV1 and DV2 are connected in series, as in Fi gur lb already described. A parallel operation of the pressure supply devices DV1 and DV2 for the multiplex operation MUX, as already described, is then not possible. Pressure build-up and pressure reduction in the Radbremszylin countries RZ1, RZ2, RZ3 and RZ4 in multiplex mode MUX can then be done with the pressure supply device DV2 or with the pressure supply device DV1 or with both pressure supply devices DV1 and DV2. If the pressure build-up Pauf in the brake circuit BK1 and a pressure decrease Pab in the other brake circuit BK2 are necessary at the same time, this pressure decrease takes place via the central outlet valve ZAV with the bypass valve BPI closed with the bypass valve BP2 open. As a result, the multiplex operation MUX is only loaded by two wheel brake cylinders RZ1 and RZ2 in the brake circuit BK1, e.g. a pressure build-up Pauf in the wheel brake cylinder RZ1 and a pressure reduction Pab in the wheel brake cylinder RZ2 of the brake circuit BK1 cannot take place at the same time. Alternatively, an outlet valve AVI or AV2 in the respective brake circuit BK1 or BK2 can also be used to reduce pressure Pab to relieve the multiplex operation MUX. On the one hand, the outlet valve AVI or AV2 can be arranged or connected either between a switching valve SV and a bypass valve BPI or BP2 or between the wheel brake cylinder and the associated switching valve SV, and on the other hand, can be connected to the storage container VB so that a direct pressure reduction Pab can take place via the outlet valve to the storage container VB. This is in particular for the immediate pressure reduction Pab in the wheel brake cylinders the front wheels makes sense. The central outlet valve ZA V is not required with this alternative.

If the pressure supply device DV1 fails, the pressure supply device DV2 can take over the function of the pressure supply device DV1 via the open bypass valves BPI and BP2, whereby multiplex operation MUX, e.g. in ABS operation, is also possible for all wheel brake cylinders. However, the pressure in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4 is then limited to the maximum pressure of the pressure supply device DV2, e.g. 120 bar.

FIG. 1c shows a fourth possible embodiment of a hydraulic system according to the invention, which is also based on the hydraulic system shown in FIG. One difference to the hydraulic system according to FIG. 1 is that it has only a single pressure supply device DV1.

The second difference to the hydraulic system according to FIG. 1 is that there is no second electrical system connection. The third difference is the design of the single pressure supply device DV1.

The pressure supply device DV1 consists of two rotary pumps Pa and Pal, which together form a two-stage pump, a brushless direct current motor or EC motor Ma, a rotor angle encoder WGa for the direct current motor Ma with electrical connection Wea, a winding connection 3a for the direct current motor Ma and the shunt 4a of the DC motor Ma. Here, the rotary pumps Pa and Pal are connected in series, ie the output of the rotary pump Pa is hydraulically connected to the input of the rotary pump Pal. At least one of the two rotary pumps Pa, Pal can be designed as a gear pump. Both rotary pumps Pa are driven by the axis Aa of the direct current motor Ma. As with the pressure supply device DV1 in FIG. 1, the rotary pump Pa is designed for the blocking pressure, for example 120 bar. The Pal rotary pump is also designed for blocking pressure. This design of the pressure supply device DV1 makes it possible, with the switching valve PD1 open, the brake pressure in brake circuit BK1, and with the bypass valves BPI and BP2 open in brake circuit BK2, except for the total pressure of the two the rotary pumps Pa and Pal, for example to a maximum of 240bar. To reduce the brake pressure in brake circuit BK1 and, if the bypass valves BPI and BP2 are open, also in brake circuit BK2, the motor torque of the DC motor Ma is reduced by undercurrent, whereby the direction of rotation of the rotary pumps Pa and Pal is reversed compared to the direction of rotation of the rotary pumps Pa and Pal at the pressure increase. Hydraulic medium then flows from the brake circuits BK1 and BK2, through the by pass valves BPI, BP2, the hydraulic line 1, the open switching valve PD1, the rotary pumps Pal and Pa and the hydraulic line HL1 back into the storage container VB.

As already described in connection with FIG. 1, the known multiplex operation MUX is possible due to the possibility that the pressure in the brake circuits BK1 and BK2 can be reduced with the pressure supply device DV1. The multiplex operation MUX with the pressure supply device DV1 has already been described in connection with FIG. This enables pressure modulations in the wheel brake cylinders RZ1, RZ2, RZ3 and RZ4 for functions such as ABS, ASR, ESP and driver assistance systems.

Figure ld shows an alternative embodiment to the fourth embodiment shown and explained in Figure lc, wherein the Druckversorgungseinrich device DV1 has two series connections of rotary pumps Pa, Pal and Pa ^' and Pal ^' . All four rotary pumps Pa, Pal and Pa ^' and Pal ^' can be driven by a single drive M and / or be gear pumps. However, it is also possible that the series connection Pa and Pal and the series connection Pa ^' and Pal ^{' are} each driven by their own drive (not shown). On the output side, the series connection of the rotary pumps Pa, Pal is connected to the brake circuit BK1 via the hydraulic line 1, the switching valve PD1 serving to separate the Rotationspum pen from the brake circuit BK1. The series connection of the rotary pumps Pa ^' , Pal ^' is connected on the output side via the hydraulic line 10 to the brake circuit BK2, this line also being able to be shut off by means of an optional isolating valve PD2. The drive or drives M of the rotary pumps can, for example, have redundant phase windings (2 × 3 phases), so that in If a phase winding fails, the drive can at least still be operated with less power.

Figures le and lf show modifications of the embodiment shown in Fig. Lb, wherein in Fig. Le the brake system has only one bypass valve BPI instead of two bypass valves BPI and BP2 and the modification shown in Figure lf has an additional central outlet valve ZAV2 , where at the same time the valves PD1 and PD2 are replaced by check valves RV1, RV2 and RV3.

The variant according to FIG. 1e is more cost-effective due to the omission of the bypass valve BP2.

In the variant according to Figure lf, the expensive Schaltven tile PD1 and PD2 and the switching valves PD3 and PD4 are also dispensed with, which are replaced by cheaper check valves RV1 to RV3. The pump Pb acts via the two check valves RV1 and RV2 in the second brake circuit BK2 and is separated from the first brake circuit BK1 via the bypass valve BPI. The first pump Pa acts via the check valve RV3 in the first brake circuit BK1. In this embodiment, the additional central outlet valve ZAV2 can be used to reduce the pressure Pab in the brake circuit BK1, via which the hydraulic medium can be discharged into the hydraulic line HL2 to the reservoir VB. The valve ZAV2 and / or the valve ZAV can be used both during normal braking and for the ABS function to reduce pressure Pab.

The central outlet valves ZAV1 and ZAV2 can advantageously have different flow cross-sections, whereby different pressure reduction gradients can be achieved. The pressure reduction Pab in the first brake circuit BK1 can also take place via the outlet valve ZAV2 and the pressure reduction Pab in the second brake circuit BK2 via the outlet valve ZAV. It is also possible for the pressure to be reduced in one or both brake circuits via both outlet valves ZAV and ZAV2 at the same time. At the same time, the pressure reduction speed in the individual wheel brake cylinders RZ1-4 can take place via a pulse width modulation control of the respectively assigned switching valves SV, whereby the flow rate in the switching valves SV during Depressurization Pab is controlled. Due to the possibilities described above, a wheel-specific pressure reduction in all wheel brake cylinders is possible at the same time.

Figure 2 shows a brake booster which can be used, for example, in Formula E vehicles. Typical for such brake boosters is:

1. The wheels of the electrically driven axle can be braked electrically through regeneration;

2. During the regenerative braking of the wheels on the driven axle, the hydraulic braking of these wheels should be reduced to a minimum (biending) in order to achieve the greatest possible efficiency of the regeneration, while maintaining the required braking force on the wheels;

3. There is no regeneration on the non-driven axle. Often there is also no brake force boost on the wheels of the non-driven axle.

Figure 2 shows the brake pedal BP, which is operated by the driver. As a result, hydraulic medium is displaced from the tandem master brake cylinder THZ, which flows directly into the brake circuit BK1 and into the wheel cylinder of the RZ1 and RZ2 of the non-driven wheels, which are thereby braked hydraulically.

A pressure supply device DV1, which can contain a rotary pump according to the invention, in particular in the form of a piston or gear pump or some other piston displacement mechanism, provides the hydraulic braking force on the driven wheels. The output of the pressure supply device DV1 is connected to the brake circuit BK2 via a hydraulic line 1. In this hydraulic line 1, a normally closed valve, the feed valve ESV, is included. A normally open isolating valve TV is provided in the brake circuit BK2. When the driver presses the brake pedal BP, the isolation valve TV is closed, the feed valve ESV opened and the pressure supply device DV1 activated in order to achieve the desired hydraulic braking effect on the driven wheels. If the pressure supply device DV1 fails, the Trennven valve TV remains open and the feed valve ESV closed, so that when the driver actuates the brake pedal BP, the hydraulic medium is now also displaced from the tandem master brake cylinder THZ into the brake circuit BK2, which is then displaced into the Wheel cylinders RZ3 and RZ4 of the non-driven wheels flow, which are thereby hydraulically braked.

By activating the pressure supply device DV1, depending on the regeneration level, hydraulic medium flows through the hydraulic line 1 and through the open feed valve ESV into the wheel brake cylinders RZ3 and RZ4, whereby the driven wheels are hydraulically braked. If the driven wheels are not to be braked hydraulically, e.g. because the regenerative braking is sufficient, the pressure supply device DV1 is not activated, or its effect is reduced to zero and no hydraulic medium flows into the wheel brake cylinders RZ3 and RZ4. If the pressure supply device DV1 contains a gear pump, for example, then hydraulic medium can be sucked in from the storage container VB through the hydraulic line HL1 to increase the pressure in the wheel brake cylinders RZ3 and RZ4.

If there are high demands on the reliability of the pressure supply device DV1, a redundant pressure supply device DVlr can be provided. This pressure supply device DV2 is connected in parallel to the pressure supply device DV1. To this end, the output of the pressure supply device DV2 is connected to the hydraulic line 1 of the pressure supply device DV1 via the hydraulic line 2. Furthermore, the pressure supply device DV2 is connected on the input side to the storage container VB via the hydraulic line HL1, so that the pressure supply device DV2 can also suck in hydraulic medium from the storage container VB.

To further increase the reliability of the hydraulic braking of the driven wheels, the output of the pressure supply device DVlr can be connected to the wheel brake cylinders RZ3 and RZ4 via a hydraulic line 3 get connected. A normally closed switching valve, in the form of the redundant feed valve ESVr, is provided in this hydraulic line 3. If the feed valve ESV fails, the pressure supply devices DV1 and DVlr can be connected to the wheel brake cylinders RZ3 and RZ4 via the hydraulic line 3 via the redundant feed valve ESVr.

Likewise, to further increase the reliability of the hydraulic braking of the driven wheels, the brake circuit BK2 can be connected to the wheel brake cylinders RZ3 and RZ4 via a hydraulic line 4. A normally open switching valve, the redundant isolating valve TVr, is provided in the hydraulic line 4. If the isolating valve TV fails, the brake circuit BK2 can be connected to the wheel cylinders RZ3 and RZ4 via the redundant isolating valve.

This system can also be expanded accordingly to control the first brake circuit BK1.

FIG. 3 shows a possible embodiment of the packaging or structure according to the invention for the pressure supply unit according to the invention. The following main function blocks must be taken into account:

A hydraulic housing HCU

B electrical control unit ECU

C Master cylinder HZ, optionally with path simulator WS, storage container Nis VB and / or pedal sensor PS

These main function blocks are described in detail in DE 10 2015 104 246 A1 and DE 10 2016 105 232 A1, and these documents can serve to explain details not described here.

The hydraulic housing A is an essential component of the pressure supply unit according to the invention, in which at least one - preferably all - rotary pump (s) Pa, Pb, Pbl at least one pressure supply device DV1, DV2 is or are arranged. If motor housings are provided for the rotary pumps Pa, Pb, these motor housings Ma, Mb of the rotary pumps Pa, Pb can be arranged either in or on the housing A.

The mechanical and / or electrical connections to the housing B of the electrical control unit ECU can also be placed in the housing A. Furthermore, solenoid valves, check valves and / or pressure transducers can be arranged in the housing A, in particular with a connection to the master brake cylinder HZ, the wheel brake cylinders RZ1-RZ4 and the pressure supply devices DV1, DV2. Both the solenoid valves and the pressure transducers require a connection to the ECU. The single or tandem master brake cylinder HZ, THZ can also be arranged in the housing A.

The housing or the block B is tightly, in particular in large contact with the housing A or connected to it and contains the components and (plug) contacts of the control electronics, which are arranged on a Lei terplatte PCB. Likewise, the plugs to the vehicle electrical system are arranged or fastened in or on the housing B.

The control unit ECU can be designed to be fully redundant or only partially redundant (hereinafter referred to as partially redundant). For example, a double on-board power supply connection or a second redundant circuit board can be provided.

The hydraulic connection lines to the brake circuits and wheel brake cylinders RZ1-RZ4 are connected to housing A. The hydraulic connections for the connecting lines can be arranged on the housing A on the side or on the front. It is also possible that the hydraulic connections are arranged at an angle, e.g. 45 ° to the horizontal, on the housing A, so that a favorable connection angle results and / or the pressure supply unit is as small and compact as possible.

If the single or tandem master brake cylinder HZ, THZ is not arranged in housing A, a further housing C must be provided for this.

In this housing C, a possibly existing Wegsimula tor WS and / or pedal sensor PS can also be included. An electrical and / or me- There is a mechanical interface to the housing B or the electronic control unit ECU.

The housings A and C are preferably arranged one behind the other in the direction of the axis A _H z, the housing B being arranged next to the housing A in the axial direction A _H z. The axes Aa, Ab of the motors Ma, Mb are preferably aligned perpendicular to A _H z.

The filler cap of the storage container VB can be arranged in front of the housings A, B and C or also to the side and / or above their center.

FIG. 3a shows the view from the front or in the direction of the axis A _H z- In the housing A, the rotary pumps Pa, Pb are arranged. The electrical motors Ma, Mb for the rotary pumps Pa, Pb can adjoin the housing A with their housings or be attached to it. However, it is also possible that the motors Ma, Mb are also arranged in the housing A. The motor axes Aa and Ab are preferably aligned parallel to one another. As shown in Figure 3, the motor axes Aa, Ab are arranged perpendicular to the axis A _H z of the master cylinder.

The solenoid valves MV and the electrical and mechanical connections 3a, 3b and 5c to the ECU or to the housing B are also arranged in the housing A.

FIG. 3a also shows the alternative face connection of the hydraulic connections for the wheel brake cylinders RZ1-RZ4. The position of the inlet connection for the storage container VB is also shown in the front or in the middle. Overall, the arrangement of the individual components shown represents a compact unit with very small dimensions.

The block C or the housing C can be arranged separately from the housings A and B, for example directly on the bulkhead of the vehicle with a connection to the pedal interface. Blocks A and B can be arranged at a suitable point in the equipment room or engine room, in which case the axes Aa, Ab of the motors Ma, Mb no longer have to be arranged at right angles to the axis of the main brake cylinder HZ, THZ. FIG. 3b shows a perspective view of the pressure supply unit according to FIGS. 3 and 3a. The housing A is next to the housing B angeord net, the housing C on the end faces Al, Bl of the housing A and B is on. The filler neck VB _E for the storage container VB is arranged on the front and above the housings A, B, C.

Figures 4 and 4a show a further possible structural embodiment form in which the motor axes Aa, Ab parallel to the axis A _H z of the master cylinder HZ; THZ are aligned. The block A is formed by a housing which is flat in the direction of the axis A _H Z. The same applies to the housing B. The surface normals of the flat sides of the housing A and B are preferably parallel or almost parallel to the axis A _H z of the master cylinder HZ; THZ aligned.

The housing C is screwed to the housing A. Of course, as described in FIG. 3a, the housing C can also be arranged spatially separated from A and B in the vehicle, e.g. on the bulkhead. The components provided in housings A, B and C do not differ from those in FIGS. 3 and 3a. The same also applies to the storage container VB.

The dashed line 9 ^″ shows the outline of a vacuum brake booster and shows the small dimensions of the pressure supply unit according to the invention.

FIG. 4b shows a perspective view of the pressure supply unit according to FIGS. 4 and 4a. The housings A, B and C are arranged in series one behind the other, the storage container VB laterally encompassing the housing and resting against the rear end face of the housing A. The filler neck VB _E for the storage container VB is arranged on the front and above the housing A, B, C, the housing C being arranged under the rear area VB _{H of} the storage container VB. Reference list

1 hydraulic line

2 hydraulic line

3a Motor winding connection of motor Ma

3b Motor winding connection of motor Mb

4 hydraulic line of the hydraulic circuit BK1

4a Shunt from motor Ma

4b Shunt from motor Mb

5 Hydraulic line of the hydraulic circuit BK2

5a on-board network connection to the on-board network BN

6 hydraulic line

7 hydraulic line

Aa axis of the motor Ma

From the axis of the motor Mb

ABS anti-lock braking system

A _H Z axis of the hydraulic housing

ASR traction control

AVI first outlet valve in brake circuit BK1

AV2 first outlet valve in brake circuit BK2

B Housing of the control and regulation device ECU

BK1 first brake circuit

BK2 second brake circuit

BN electrical system

BN1 first electrical system connection

BN2 second on-board power supply connection

BN2 'auxiliary electrical system connection

BPI first bypass valve

BP2 second bypass valve

BP brake pedal

DG pressure transducer

Dr Thrush

DV1 first pressure supply device

DVlr redundant pressure supply device

DV2 second pressure supply device

Df Angle of rotation of the rotor of the rotary pump

At time within which the volume V _so n should be conveyed

EC electrically commutated

ECU control and regulation device

ESP electronic stability program

ESV feed valve, normally closed switching valve

ESVr redundant feed valve, normally closed switching valve

FV switching valve

HL1 first hydraulic line to the storage container VB

HL2 second hydraulic line to the storage container VB

Ko piston of the master brake cylinder SHZ

KWS force-displacement sensor

M drive

Ma DC motor of the pressure supply device DV1

Mb DC motor of the pressure supply device DV2 MUX hydraulic multiplex operation

MV solenoid valve

Pa Rotary pump of the pressure supply device DV1 Pal Rotary pump of the pressure supply device DV1 Pa 'Rotary pump of the pressure supply device DV1 Pal' Rotary pump of the pressure supply device DV1 Pab Pressure reduction

P on pressure build-up

Pb rotary pump of the pressure supply device DV2

Pbl rotary pump of the pressure supply device DV2

PD1 switching valve

PD2 switching valve

PD3 switching valve

PD4 switching valve

PS pedal travel sensor

PV pressure volume

RV1 check valve

RV2 check valve

RV3 check valve

RZ1 first wheel brake cylinder

RZ2 second wheel brake cylinder

RZ3 third wheel brake cylinder

RZ4 fourth wheel brake cylinder

SHZ single master cylinder

SV switching valve

St connector

THZ tandem master cylinder

TV isolating valve, normally open switching valve

TVr redundant isolating valve, normally open switching valve

ÜV pressure relief valve

V volume of hydraulic medium

VB storage container

VL hydraulic connection line

VLa connecting line from bypass valve BPI to bypass valve BP2 v _M Angular rotation speed of the rotor of the rotary pump

VsoM required volume of hydraulic medium

Wea electrical connection of the angle encoder WGa

Web electrical connection of the angle encoder WGb

WGa angle encoder of the rotor of the motor Ma

WGb angle encoder of the rotor of the motor Mb

WS path simulator

ZAV central outlet valve

ZAVr redundant exhaust valve

ZAV2 additional central outlet valve

Claims

1. Pressure supply unit for a hydraulic system with at least one consumer circuit (BK1, BK2) and with at least one rotary pump (Pa,

Pb), where

- either by means of at least one rotary pump (Pa, Pb) one

Volume delivery in at least one delivery direction in at least one consumer circuit (BK1, BK2) takes place in such a way that a certain required volume (V eg in [cm ³ ]) of hydraulic medium, in particular for pressure build-up (Pauf), pressure reduction (Pab) and / or an adjustment of an aggregate is promoted

and or

- That at least two rotary pumps (Pa, Pb) are provided, with at least one of the rotary pumps (Pa, Pb) being able to build up and reduce the pressure in at least one consumer circuit (BK1, BK2) by means of a corresponding energization of the respective electric motor drive (Ma, Mb) is.

2. Pressure supply unit according to claim 1, characterized in that at least two rotary pumps (Pa, Pb) for different maximum pressure level (Pl _max, P2 _ma x) and / or different pressure ranges (Pl _m m <PI <P? / P2 _min <P2 < P2 _ma x) are designed, in particular P? max ^ P2max-

3. Pressure supply unit according to claim 1 or 2, characterized

net, that the volume is conveyed by means of a volume control in such a way that the necessary angle of rotation (Df) for a required volume (V _so n) of hydraulic medium is determined via the proportionality between the angle of rotation (Df) of the rotor of the rotary pump and the volume (V) conveyed is calculated and then by means of the drive (Ma) of the rotary pump (Pa) the rotor is adjusted by the calculated angle of rotation.

4. Pressure supply unit according to claim 1 or 2, characterized in that the volume delivery takes place by means of a volume control, the required delivery volume (V) being realized via the speed of the rotary pump (Pa, Pb) and the switch-on duration of the rotary pump (Pa, Pb) becomes.

5. Pressure supply unit according to one of claims 1 to 3, characterized in that the volume control takes into account the time (At) within which the required volume (V _so n) of hydraulic medium is to be conveyed, the speed (v _M ) of the rotor of the rotary pump (Pa) is adapted to the available time (At).

6. Pressure supply unit according to one of claims 1 to 4, characterized in that the pressure supply unit has at least two pressure supply devices (DV1, DV2), one pressure supply device (DV1, DV2) each having at least one rotary pump (Pa, Pb; Pb, Pbl ) and a drive (Ma, Mb) for driving the rotary pump, the pressure supply devices (DV1,

DV2) for the same or different maximum pressure level (Pl x _ma, _ma x P2) and / or the same, overlapping or different print preparation che (PLmin <PI <P? Max, are designed P2 _mi n <P2 <P2 _max).

7. Pressure supply unit according to one of claims 1 to 4, characterized in that the pressure supply unit has only one Druckver supply devices (DV1), wherein the pressure supply device (DV1) either

- at least two hydraulic rotary pumps connected in series (Pa, Pal),

in particular in the form of a two-stage or multi-stage rotary pump, or

- two series connections of at least two hydraulically in series each

switched rotary pumps (Pa, Pal; Pa ^' , Pal ^' ),

with the rotary pumps (Pa, Pal; Pa ^' , Pal ^' ) are driven by a drive (M).

8. Pressure supply unit according to one of the preceding claims, characterized in that at least one rotary pump (Pa), in particular the rotary pump for volume control and / or the rotary pump for pressure build-up and reduction, a rotary pump with piston, a gear pump, a vane pump or a Rotary vane pump is.

9. Pressure supply unit according to one of claims 1 to 7, characterized in that at least the rotary pump (Pa) for volume control either

- A rotary piston pump, in particular in the form of a rotary piston pump,

Rotary vane pump, vane pump, rotary piston pump, toothed ring or

Gear pump, is, or

- is a radial pump, in particular in the form of a radial piston pump, or

- is a flow pump, in particular in the form of a centrifugal pump, or

- A positive displacement pump with a rotating rotor which, with a wall surrounding it, forms self-contained volumes in which the

Hydraulic medium is conveyed through the rotation is.

10. Pressure supply unit according to one of the preceding claims, characterized in that the rotary pump (Pa, Pb) is a 1-circuit rotary pump which has only one hydraulic circuit, in particular in the form that it has only one input and one output and a rotor having.

11. Pressure supply unit according to one of claims 1 to 8, characterized in that the rotary pump (Pa, Pb) is a multi-circuit Rota tion pump, which has several separate and sealed hydraulic circuits.

12. Pressure supply unit according to one of the preceding claims, characterized in that the rotary pump (Pa, Pb) is single-stage or multi-stage, with several stages being arranged hydraulically in series.

13. Pressure supply unit according to claim 11, characterized in that the rotary pump (Pb) is a multi-stage pump, with a drive (Ma, Mb) drives the multi-stage pump, which drives at least two hydraulic series-connected rotary pumps (Pa, Pal; Pb, Pbl).

14. Pressure supply unit according to one of the preceding claims, characterized in that the rotary pump (Pb) not provided for volume control is a continuously conveying pump, in particular in the form of a piston pump, vane pump, rotary vane pump or gear pump.

15. Pressure supply unit according to claim 13, characterized in that the continuously delivering pump (Pb, Pbl) is driven by means of an electric motor drive (Mb) and sets or regulates a predetermined pressure in a consumer circuit (BK2).

16. Pressure supply unit according to one of the preceding claims, characterized in that by means of the at least two rotary pumps (Pa, Pb) at least two consumer circuits (BK1, BK2), in particular special in the form of brake circuits, are supplied with hydraulic medium, with at least one in each case Consumer (RZ) is arranged in a consumer circuit (BK1, BK2), with a rotary pump (DV1, DV2) being assigned to a consumer circuit (BK1, BK2).

17. Pressure supply unit according to claim 15, characterized in that the consumer circuits (BK1, BK2) can be connected via a hydraulic connec tion line (VL, VLa), with at least one switchable valve (BPI, BP2), in particular two switchable bypass valves connected in series , are provided for the optional opening and closing of the connection line (VL), whereby each consumer circuit (BK1, BK2) a hydraulic line (4, 5) which each connects the one or one of the switchable valve (s) (BPI, BP2) with the consumers (RZ1-RZ4) of their brake circuit (BK1, BK2), one Rotary pump (DV1) is or can be connected on the pressure side with one hydraulic line (4) directly or via at least one interposed valve (PD1), and that the other rotary pump (DV2) on the pressure side with the other hydraulic line (5) directly or via at least one Valve (RV1, RV2) connected or connectable.

18. Pressure supply unit according to claim 16, characterized in that the hydraulic circuits (BK1, BK2) can be hydraulically separated from one another by shutting off at least one valve (BPI, BP2), such that each rotary pump (DV1, DV2) only enters its hydraulic circuit (BK1 , BK2) acts, and that if the connecting line (VL, VLa) is not closed, each rotary pump (DV1, DV2) can also act in the other hydraulic circuit (Bkl, BK2).

19. Pressure supply unit according to claim 16 or 17, characterized in that the actual pressure (P _ist ) in both hydraulic circuits (BK1, BK2) can be determined via the connecting line (VL, VLa) with a pressure sensor (DG), and in particular can be used for volume delivery (Q).

20. Pressure supply unit according to claim 18, characterized in that in case of failure of the pressure sensor (DG) of the actual pressure (P _ist) over the ge measured motor current, in particular using shunt resistors 4a, 4b) can be determined or estimated.

21. Pressure supply unit according to one of the preceding claims, characterized in that the minimum pressure (Plmin) of the first Rota tion pump (Pa) less than or equal to the minimum pressure (P2 _mi n) of the second rotary pump (Pb) and the maximum pressure (Pl _max ) of the first rotary pump (DV1) is less than the maximum pressure (P2 _ma x) of the second rotary pump (DV2) is.

22. Pressure supply unit according to one of the preceding claims, characterized in that the electrical power of the drive (Ma) of the rotary pump (Pa) of the first pressure supply device (DV1) is greater than the electrical power of the drive (Mb) of the rotary pump (Pb) of the second pressure supply device (DV2).

23. Pressure supply unit according to one of the preceding claims, characterized in that the rotary pumps (Pa, Pb) of two pressure supply devices (DV1, DV2) can be hydraulically connected in series via a connecting line (6).

24. Pressure supply unit according to claim 22, characterized in that the connecting line (6) can be selectively blocked or opened by means of a switchable, in particular normally closed, valve (PD3).

25. Pressure supply unit according to one of the preceding claims, characterized in that the input of the rotary pump (Pa) via a connecting line (7) with a storage container (VB) is in connec tion, this connecting line (7) with the connecting line (6) at Point (A), and in the line section (7a) between point (A) and the storage container (VB) a check valve (RV3), in particular with a large flow cross-section, is arranged, which prevents hydraulic medium from flowing from point (A) can flow towards the storage container (VB).

26. Pressure supply unit according to claim 24, characterized in that a switchable, in particular normally closed, valve (PD4) is arranged parallel to the check valve (RV3), such that when the switching valve (PD4) is open, hydraulic medium from the rotary pump (Pa) to the Storage container (VB) can flow.

27. Pressure supply unit according to one of the preceding claims, characterized in that the hydraulic connection of the output side of a rotary pump (Pa, Pb; Pbl) to the respective associated consumer circuit (BK1, BK2) and / or the hydraulic connection of the input side of a rotary pump ( Pa, Pb) to the storage tank (VB) can be shut off by means of a switchable, in particular normally closed, valve (PD1, PD2) or that at least one check valve (RV1, RV2, RV3) is arranged in this connecting line, which blocks in the direction of the pump (Pa, Pb).

28. Pressure supply unit according to one of the preceding claims, characterized in that the current and / or the voltage for the electromotive drive (Ma, Mb) for a required delivery rate and / or delivery direction is set or regulated by means of a converter.

29. Pressure supply unit according to one of the preceding claims, characterized in that each hydraulic circuit (BK1, BK2) is assigned a central outlet valve (ZAV, ZAV2), via which a pressure reduction (Pab) both during normal braking and during the ABS function can be done in the storage container (VB).

30. Pressure supply unit according to claim 29, characterized in that the central outlet valves (ZAV, ZAV2) have different flow cross-sections.

31. Pressure supply unit according to claim 29 or 30, characterized in that the pressure reduction (Pab) in the first hydraulic circuit (BK1) via the central outlet valve (ZAV2) and the pressure reduction (Pab) in the second central outlet valve (ZAV) takes place and / or that the pressure reduction in one or both hydraulic circuits (BK1, BK2) takes place simultaneously via both outlet valves (ZAV, ZAV2) towards the storage container.

32. Pressure supply unit according to one of claims 29 to 31, characterized in that when the pressure is reduced via at least one open central outlet valve (ZAV, ZAV2), the pressure reduction in at least one wheel brake cylinder (RZ1-4) via the switching valve (SV) of the controlled with pulse width modulation respective wheel brake cylinder (RZ-4) is controlled.

33. Hydraulic system, in particular in the form of a braking system with a Pressure supply unit according to one of the preceding claims.

34. Hydraulic system according to claim 33, characterized in that the hydraulic system is part of an electric vehicle, only one pressure supply device (DV1) being provided, which in particular only serves to generate brake pressure in a brake circuit (BK2).

35. Hydraulic system according to claim 34, characterized in that the hydraulic connecting line between the pressure supply device (DV1) and the brake circuit (BK2) can either be shut off or opened by means of a switching valve (ESV).

36. Hydraulic system according to claim 33 or 34, characterized in that a brake cylinder (THZ) which can be actuated by means of a brake pedal (BP), in particular in the form of a tandem master brake cylinder with floating piston, is provided, with a brake pressure in one via the brake cylinder (THZ) or, especially if the pressure supply device (DV1) fails, both brake circuits (BK1, BK2) can be set up.

37. Hydraulic system according to one of claims 33 to 36, characterized in that a further pressure supply device (DVlr) is arranged parallel to the pressure supply device (DV1), which in particular takes over or supports its function if the pressure supply device (DV1) fails, and that if both pressure supply devices (DV1, DVlr) fail, pressure can build up in both brake circuits via the brake cylinder (THZ).

38. Hydraulic system according to one of claims 33 to 37, characterized in that if the pressure supply device (DV1) or pressure supply devices (DV1, DVlr) fails, a switchable, in particular normally open, isolating valve (TV) is opened in such a way that over this separating valve (TV) hydraulic medium from the brake cylinder (THZ) in the brake circuit (BK2) reaches the pressure build-up.

39. Hydraulic system with a pressure supply unit according to one of claims 1 to 32 and / or according to one of claims 25 to 30, characterized characterized in that the at least one rotary pump (Pa, Pb) is or are arranged in a housing (A), in particular their axes being aligned parallel to one another.

40. Hydraulic system according to claim 39, characterized in that a master cylinder in the form of a single or tandem master cylinder (SHZ, THZ) is provided which can be actuated by means of a brake pedal (BP), the single or tandem master cylinder (SHZ , THZ) is arranged in the housing (A) together with the rotary pumps (Pa, Pb) or in a housing (C) formed separately therefrom.

41. Hydraulic system according to claim 39 or 40, characterized in that the axis of the at least one rotary pump (Pa, Pb) is arranged parallel or perpendicular to the axis of the master brake cylinder (SHZ, THZ).

42. Hydraulic system according to one of claims 39 to 41, characterized in that additional solenoid valves, in particular the valves required for all control and regulation functions (ESP, ABS), are also arranged in the pump housing (A).

43. Hydraulic system according to one of claims 39 to 42, characterized in that the electronic control and regulating unit (ECU) is arranged in an ECU housing (B), in particular the sensors being arranged or in the ECU housing (B) are arranged on this, and / or the control and regulating unit (ECU) is partially or fully redundant.

44. Hydraulic system according to one of claims 39, 42 or 43, characterized in that the hydraulic system has an electric pedal or an actuation switch, in particular for level 5 in automatically driving vehicles (AD).

45. Hydraulic system according to one of claims 33 to 44, characterized in that in the case of a non-redundant electrical system, an auxiliary electrical system, for example, has U-Caps (BN2 ') is provided for some braking operations, in particular so that braking until the vehicle comes to a standstill are possible if the on-board network fails while driving and thus also when the vehicle is being driven.

46. Hydraulic system according to one of claims 33 to 45, characterized in that the housings (A, B, C) together form a module, in particular a 1-box module.