A self-propelled filling pipe for a liquid manure spreader has a frame, an elongated pipe on the frame having a lower inlet end and an elevated outlet end, at least two wheels mounted on the frame, a caster wheel mounted on the elongated pipe proximate the lower inlet end and a fluid drive system. The fluid drive system includes a hydraulic pump, a first hydraulic circuit connecting the hydraulic pump to a plurality of hydraulic motors drivingly connected to the wheels. The fluid drive system also includes a second hydraulic circuit connecting the hydraulic pump to a hydraulic motor operatively connected to the caster wheel. A prime mover provides power to the hydraulic pump to power the hydraulic motors to rotate the caster wheel thereby steering the filling pipe and/or to drive the wheels thereby propelling the filling pipe on the ground.

A hydraulic steering arrangement is shown having a steering unit and two working ports each of which being connected to the steering unit by a working line (3), wherein an anti jerk valve (9) is arranged in each working line (3), the anti jerk valve (9) having a valve element (12) being loaded in opening direction by the pressure in the working line (3) and in closing direction by restoring means (17). A vehicle equipped with such a steering arrangement should have a good comfort. To this end the valve element (12) is loaded in closing direction by the pressure in the working line (3) via delay means (21).

A hydraulic steering arrangement is shown having a steering unit and two working ports each of which being connected to the steering unit by a working line (3), wherein an anti jerk valve (9) is arranged in each working line (3), the anti jerk valve (9) having a valve element (12) being loaded in opening direction by the pressure in the working line (3) and in closing direction by restoring means (17). A vehicle equipped with such a steering arrangement should have a good comfort. To this end the valve element (12) is loaded in closing direction by the pressure in the working line (3) via delay means (21).

An articulated work vehicle with linked front and rear frames includes a joystick lever, a hydraulic actuator, a control valve, a force imparting component, a joystick displacement sensor, a steering angle sensor, and a controller. The joystick lever is operated to allow a target steering angle to be set. The hydraulic actuator is driven hydraulically to change an actual steering angle. The control valve controls flow of fluid supplied to the hydraulic actuator to eliminate deviation between the target and actual steering angles. The force imparting component imparts an assist force or a counterforce to the operation of the joystick lever. The controller controls the force imparting component so that a counterforce is imparted to the operation of the joystick lever when the joystick lever has been operated in an opposite direction from a rotation direction of the front frame based on detections of the sensors.

An articulated work vehicle with linked front and rear frames includes a joystick lever, a hydraulic actuator, a control valve, a force imparting component, a joystick displacement sensor, a steering angle sensor, and a controller. The joystick lever is operated to allow a target steering angle to be set. The hydraulic actuator is driven hydraulically to change an actual steering angle. The control valve controls flow of fluid supplied to the hydraulic actuator to eliminate deviation between the target and actual steering angles. The force imparting component imparts an assist force or a counterforce to the operation of the joystick lever. The controller controls the force imparting component so that a counterforce is imparted to the operation of the joystick lever when the joystick lever has been operated in an opposite direction from a rotation direction of the front frame based on detections of the sensors.

A work vehicle includes a steering wheel, a steering cylinder, a steering valve, a feed line, a return line, an electromagnetic valve, and a controller. The steering valve is configured to supply hydraulic fluid to the steering cylinder in response to steering of the steering wheel. The feed line is configured to feed the hydraulic fluid from the steering valve to the steering cylinder. The return line is configured to return the hydraulic fluid from the steering cylinder to the steering valve. The electromagnetic valve is disposed between the feed line and the return line. The controller opens the electromagnetic valve in response to an oil pressure in the feed line.

A work vehicle includes a steering wheel, a steering cylinder, a steering valve, a feed line, a return line, an electromagnetic valve, and a controller. The steering valve is configured to supply hydraulic fluid to the steering cylinder in response to steering of the steering wheel. The feed line is configured to feed the hydraulic fluid from the steering valve to the steering cylinder. The return line is configured to return the hydraulic fluid from the steering cylinder to the steering valve. The electromagnetic valve is disposed between the feed line and the return line. The controller opens the electromagnetic valve in response to an oil pressure in the feed line.

Electronically controlled hydraulic valves can be directly mounted to rear steering cylinders of a four wheel steering machine to improve steering, reduce space consumption, reduce leak points and allow ease of routing. The valves can receive hydraulic fluid from a pump and release hydraulic fluid to tank, while controlling an amount of hydraulic fluid to the steering cylinder via inlets and outlets in direct contact. The valves can be controlled by a controller that is also in communication with position sensors configured to sense positions of the front and rear steering cylinders, so that the directly mounted valves in the rear can be correspondingly controlled to follow steering in the front.

Electronically controlled hydraulic valves can be directly mounted to rear steering cylinders of a four wheel steering machine to improve steering, reduce space consumption, reduce leak points and allow ease of routing. The valves can receive hydraulic fluid from a pump and release hydraulic fluid to tank, while controlling an amount of hydraulic fluid to the steering cylinder via inlets and outlets in direct contact. The valves can be controlled by a controller that is also in communication with position sensors configured to sense positions of the front and rear steering cylinders, so that the directly mounted valves in the rear can be correspondingly controlled to follow steering in the front.

The present application discloses a steering control system, a method and a crane. The steering control system includes: one or more first angle sensors, one or more second angle sensors, and a steering controller; each of the first angle sensors collects an actual steering angle of a wheel corresponding to a mechanical steering axle as a first steering angle; each of the second angle sensors an actual steering angle of a wheel corresponding to an electrically controlled steering axle as a second steering angle; the steering controller obtains a theoretical steering angle of the wheel corresponding to the electrically controlled steering axle in a corresponding travel mode according to the first steering angle, and compares the second steering angle with the theoretical steering angle, to control the wheel corresponding to the electrically controlled steering axle to steer according to a difference therebetween.