A controller device for controlling an effective value of an electric load current at a time-variant load is provided. The controller device provides at the time-variant load a voltage pulse sequence having a duty cycle in at least one pulse phase of the voltage pulse sequence. A sample value of the electric load current is acquired at the time-variant load, to determine an actual effective value of the electric load current using a dependency stored in the controller device. The actual effective value is assigned to the sample value of the electric load current. A difference value between the actual effective value of the electric load current and a setpoint effective value of the electric load current is determined, and adapted duty cycle of the voltage pulse sequence is determined from the difference value, and provides at the time-variant load an adapted voltage pulse sequence having the adapted duty cycle.

A controller device for controlling an effective value of an electric load current at a time-variant load is provided. The controller device provides at the time-variant load a voltage pulse sequence having a duty cycle in at least one pulse phase of the voltage pulse sequence. A sample value of the electric load current is acquired at the time-variant load, to determine an actual effective value of the electric load current using a dependency stored in the controller device. The actual effective value is assigned to the sample value of the electric load current. A difference value between the actual effective value of the electric load current and a setpoint effective value of the electric load current is determined, and adapted duty cycle of the voltage pulse sequence is determined from the difference value, and provides at the time-variant load an adapted voltage pulse sequence having the adapted duty cycle.

The present application provides a full hydraulic synchronous steering system for a low-speed heavy-load vehicle, where the system includes: a steering control mechanism and a steering actuator; by determining a desired steering curve between a steering wheel angle and a rear wheel angle, when a steering error exceeds an allowable error, a controller controls the opening and closing of an oil replenishment solenoid valve (5) and an oil discharge solenoid valve (4) to adjust a flow rate of the oil flowing into a steering cylinder (7), so as to ensure that the steering error is within an allowable error range, thereby implementing synchronous steering. A method for manipulating the full hydraulic synchronous steering system is further provided. The full hydraulic synchronous steering system and the method can improve synchronous steering capability of the low-speed heavy-load vehicle and change a steering ratio, thereby improving safety and direction feeling of a driver.

A steering system for a vehicle is provided. The steering system includes a mechanical interface coupled to an auxiliary hydraulic steering pump and an output of a transmission. In the system, the transmission is mechanically coupled to a motive power source and the auxiliary hydraulic steering pump is hydraulically coupled to a hydraulic steering assembly.

A steering system for a vehicle is provided. The steering system includes a mechanical interface coupled to an auxiliary hydraulic steering pump and an output of a transmission. In the system, the transmission is mechanically coupled to a motive power source and the auxiliary hydraulic steering pump is hydraulically coupled to a hydraulic steering assembly.

One example provides a ride on air injection machine including one or more steerable wheels, a compressed air system providing compressed air, one or more air inject tines to inject compressed air from the compressed air system into the grounds, and a steering system. The steering system includes a steering wheel, a cylinder coupled to the steerable wheels, the cylinder including opposing internal chambers and being moveable to steer the steerable wheels and a control valve assembly to direct compressed air from the compressed air system to the internal chambers and to bleed compressed air from the internal chambers based on a position of the steering wheel to move the cylinder steer the steerable wheels.

One example provides a ride on air injection machine including one or more steerable wheels, a compressed air system providing compressed air, one or more air inject tines to inject compressed air from the compressed air system into the grounds, and a steering system. The steering system includes a steering wheel, a cylinder coupled to the steerable wheels, the cylinder including opposing internal chambers and being moveable to steer the steerable wheels and a control valve assembly to direct compressed air from the compressed air system to the internal chambers and to bleed compressed air from the internal chambers based on a position of the steering wheel to move the cylinder steer the steerable wheels.

The present disclosure relates to a hydraulic steering device of an agricultural work vehicle comprising a steering pump for supplying a working fluid; an automatic steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when automatic steering is performed by a control unit; a manual steering unit which uses the working fluid to change the traveling direction of the agricultural work vehicle when manual steering is performed by operating a steering handle; and an automatic cut-off unit which is for selectively cutting off the supply of the working fluid for the automatic steering to a steering cylinder of the agricultural work vehicle according to whether the manual steering is performed.

A system for hydraulic parallel work systems is provided. The system includes a fixed displacement pump (110), a closed-center circuit (300), an open-center hand metering unit (HMU) (200), and a tank (120). The closed-center circuit is in fluid communication with the fixed displacement pump. The open-center HMU is in fluid communication with the fixed displacement pump at an inlet port (204) of the HMU. The tank is fluidly connected to the inlet port of the HMU when the HMU is inactive.

A work vehicle includes a bypass passage formed in an operational valve of a dump cylinder and configured to feed pressure oil from a hydraulic pump to a power steering device when the operational valve is under a neutral state and an oil feeding passage equipped with an orifice, the orifice-equipped oil feeding passage being configured to feed the pressure oil from the hydraulic pump to a rod side oil chamber of the dump cylinder when the operational valve is under the neutral state.