Fail-safe braking system

A braking system comprising:

• at least two wheel brake cylinders, each of which is part of
• separate wheel circuits;
• at least one electrically driven pressure supply to build up pressure and reduce pressure in the at least two wheel brake cylinders;
• at least one reservoir;
• at least one electronic control and regulation device;
• at least two switching valves;
• wherein
• each of the at least two wheel brake cylinders is connected via a respective hydraulic connecting line to one of the at least two switching valves to disconnect and connect a hydraulic connection of the respective wheel brake cylinder and at least one other hydraulic main line, via the switching valve connectable at least to the pressure supply;
• the at least two switching valves are normally open 2/2-way valves;
• at least the hydraulic connecting line and the wheel one of the wheel circuits;
• at least one of the at least two switching valves or all of the at least two switching valves have no check valve or no check valve is connected in parallel to the at least one switching valve;
• in order to prevent one of the at least two switching valves from closing when the pressure is reduced via the one of the at least two switching valves, one or more of the following is included:
• a) a valve actuator of the one of the at least two switching valves is force-loaded with a return force in an open position provided by a return spring and/or a magnetic force;
• b) the pressure supply is configured to adjust or regulate a pressure reduction rate to close the one of the at least two switching valves;
• c) the hydraulic connecting line connecting the pressure at least two switching valves includes a parallel circuit including a throttle and a check valve that blocks in a direction of the pressure supply;
• d) a shut-off valve to connect or disconnect the wheel circuits from a master brake cylinder includes a flow cross-section configured to, when a pressure drop occurs in one of the wheel circuits, prevent the one of the at least two switching valves from sticking;
• e) the shut-off valve is opened and closed in a pulse width mode in order to limit a flow rate or a flow velocity to a level such that tearing of the one of the at least two switching valves is prevented;
• f) a drive of the pressure supply includes a multiphase electric motor including an electrical connection of windings configured such that, when a failure of a motor control and/or an electrical control device occurs, the electric motor is operated in a generator mode and a winding circuit of the electric motor acts as a brake for a piston of the pressure supply to limit or reduce a pressure reduction rate in the wheel circuits.