Abstract: Disclosed is an electro-hydraulic relay valve and corresponding valve assembly for a SAHR brake. First actuators are arranged to act on a first end of a floating valve spool and second actuators are arranged to act on a second end of the valve spool. One of the second actuators can receive hydraulic pressure from a pilot valve. In a first valve position, the pressure supply port communicates with the working port and the tank port is closed. In a second valve position, the pressure supply port is closed and communicates via a first sense line with one of the first actuators, the working port directs pressure to the tank port, the tank port communicates via a second sense line with another of the first actuators, and the working port communicates via a third sense line with one of the second actuators. In a central position, all three ports are closed.

Abstract: Disclosed is an electrohydraulic valve that includes a pressure reducing valve in a single monoblock valve body. In one example, the valve is a reverse modulating valve with a body having an output port (B), a pressure supply port (P), and a tank port (T). The electrohydraulic valve is configured as a spool valve having a return spring, a feedback pin, and a proportional solenoid, where the proportional solenoid is arranged to oppose the return spring and feedback pin. An externally adjustable pressure reducing valve is between the pressure supply port (P) and the electrohydraulic spool valve. Above a current threshold, increasing current to the solenoid proportionally reduces pressure at the output port (B). Examples of a braking system incorporating the valve are also disclosed.

Abstract: Disclosed is an electro-hydraulic relay valve and corresponding valve assembly for a SAHR brake. First actuators are arranged to act on a first end of a floating valve spool and second actuators are arranged to act on a second end of the valve spool. One of the second actuators can receive hydraulic pressure from a pilot valve. In a first valve position, the pressure supply port communicates with the working port and the tank port is closed. In a second valve position, the pressure supply port is closed and communicates via a first sense line with one of the first actuators, the working port directs pressure to the tank port, the tank port communicates via a second sense line with another of the first actuators, and the working port communicates via a third sense line with one of the second actuators. In a central position, all three ports are closed.