Abstract: A rotary valve includes a valve cap, a valve body, a rotary valve disk, and an actuator. The valve body includes first and second sets of fluid flow passages, with each set having a drain, a fluid inlet, a fluid outlet and a fourth passage connected to the fluid outlet passage. The rotary disk includes first and second connecting passages. The actuator and rotary disk have first and second positions in which various passages of each set of fluid flow passages aligned with and connected by the connecting passages and a third position in which the fluid outlet passage of each set of fluid flow passages is connected to the drain passage of the other set of fluid flow passages.

Abstract: A hydraulic system, and associated method of control, includes an operator input device, a source of hydraulic fluid flow, and a plurality of actuators. At least one valve associated with each actuator for controlling a flow of fluid to and from the actuator. A controller is responsive to a signal from the operator input device to calculate a hydraulic pressure to be supplied to each of the actuators. The controller controls the source of hydraulic fluid flow and the valves for powering the actuators with the calculated hydraulic pressure. The controller also monitors a sensed parameter to determine whether the actuators can be powered with the calculated hydraulic pressure, and in response to a determination that the actuators cannot be powered with the calculated hydraulic pressure, calculates a discrepancy ratio and modifies actuation of the actuators with the discrepancy ratio.

Abstract: A rotary valve includes a valve cap, a valve body, a rotary valve disk, and an actuator. The valve body includes first and second sets of fluid flow passages, with each set having a drain, a fluid inlet, a fluid outlet and a fourth passage connected to the fluid outlet passage. The rotary disk includes first and second connecting passages. The actuator and rotary disk have first and second positions in which various passages of each set of fluid flow passages aligned with and connected by the connecting passages and a third position in which the fluid outlet passage of each set of fluid flow passages is connected to the drain passage of the other set of fluid flow passages.

Abstract: A hydraulic system, and associated method of control, includes an operator input device, a source of hydraulic fluid flow, and a plurality of actuators. At least one valve associated with each actuator for controlling a flow of fluid to and from the actuator. A controller is responsive to a signal from the operator input device to calculate a hydraulic pressure to be supplied to each of the actuators. The controller controls the source of hydraulic fluid flow and the valves for powering the actuators with the calculated hydraulic pressure. The controller also monitors a sensed parameter to determine whether the actuators can be powered with the calculated hydraulic pressure, and in response to a determination that the actuators cannot be powered with the calculated hydraulic pressure, calculates a discrepancy ratio and modifies actuation of the actuators with the discrepancy ratio.