Uni-directional redundant solenoid valve for brake actuator and system thereof

An electrohydraulic control system for controlling a braking system of a work machine, comprising:

• a controller operatively connected to a first communication link and to a second communication link;
• a source of hydraulic fluid;
• a brake actuator configured for moving between an engaged and disengaged position;
• a valve body forming a bore and a port, the port being fluidly coupled to the bore, to the source of hydraulic fluid, and to the brake actuator;
• a valve spool disposed within the bore and in fluid communication with the port, the valve spool including at least a first land and a second land;
• an armature positioned with respect to the valve spool to move the valve spool axially within the bore between a first position blocking a fluid connection between the source of hydraulic fluid and the port and a second position;
• a spring, including a spring force, the spring disposed within the bore and biasing the valve spool to its first position;
• and
• a first electromagnetic coil and a second electromagnetic coil arranged relative to one another and the armature for forming a magnetic field when energized;
• and
• wherein, the first electromagnetic coil is in electrical communication with the controller to receive a first electrical signal via the first communication link, and the second electromagnetic coil is in electrical communication with the controller to receive a second electrical signal via the second communication link;
• further wherein, the first communication link and the second communication link are independent from one another and independently actuate each of the first electromagnetic coil and the second electromagnetic coil, and wherein the first electrical signal and the second electrical signal are respectively communicated by the controller to the first electromagnetic coil and the second electromagnetic coil to independently energize both the first electromagnetic coil and the second electromagnetic coil to provide a resulting net force greater than the spring force, wherein the spring force biases the valve spool to its first position when at least one of the first electromagnetic and second electromagnetic coil is in its de-energized state.

A work machine, comprising:

• a controller operatively connected to a first communication link and to a second communication link, the controller including control logic to independently de-energize or energize each of a first electromagnetic coil and a second electromagnetic coil of a valve system, wherein if there is an error in the control logic and if both of the first electromagnetic coil and the second electromagnetic coil are not energized or de-energized, the valve system does not change state;
• a braking system comprising a brake actuator for engaging or disengaging a brake;
• a source of hydraulic pressure;
• and
• an electrohydraulic valve system comprising:
• a valve body forming a bore and a port, the port being fluidly coupled to the bore and the brake actuator;
• a valve spool disposed within the bore and in fluid communication with the port, the valve spool including at least a first land and a second land;
• an armature positioned with respect to the valve spool to move the valve spool axially within the bore between a first position and a second position;
• a spring, including a spring force, the spring disposed within the bore and biasing the valve spool to its first position;
• and
• the first electromagnetic coil and the second electromagnetic coil arranged relative to one another and the armature for forming a magnetic field when energized;
• wherein, the first electromagnetic coil is in electrical communication with the controller via the first communication link, and the second electromagnetic coil is in electrical communication with the controller via the second communication link;
• wherein, the first communication link and the second communication link are independent from one another and independently control the first electromagnetic coil and the second electromagnetic coil;
• further wherein, the spring biases the valve spool to its first position when at least one of the first and second electromagnetic coil is in its de-energized state;
• and
• further wherein when the first and second electromagnetic coils are energized independently, the second net force is greater than the first net force to bias the valve spool to its second position, wherein the spring force biases the valve spool to its first position when at least one of the first electromagnetic coil and second electromagnetic coil is in its de-energized state.