A hydraulic steering arrangement includes a supply port arrangement having at least a supply port, a return port arrangement having at least a return port, a working port arrangement having two working ports, a first valve arrangement having a first supply side connected to the supply port arrangement and a first output side connected to the working port arrangement, a second valve arrangement having a second supply side connected to the supply port arrangement and a second output side connected to the working port arrangement, and a steering command device. In a neutral steering angle, the second valve arrangement connects the first output side to the return port arrangement and the first valve arrangement connects the second output side to the return port arrangement.

A hydraulic steering arrangement includes a supply port arrangement having at least a supply port, a return port arrangement having at least a return port, a working port arrangement having two working ports, a first valve arrangement having a first supply side connected to the supply port arrangement and a first output side connected to the working port arrangement, a second valve arrangement having a second supply side connected to the supply port arrangement and a second output side connected to the working port arrangement, and a steering command device. In a neutral steering angle, the second valve arrangement connects the first output side to the return port arrangement and the first valve arrangement connects the second output side to the return port arrangement.

The present technology describes systems and methods for varying a pump speed of an electric truck. In examples, vehicle efficiency losses may be reduced by varying the speed of a hydraulic pump associated with a power steering gear. An electronic control unit (ECU) may receive a set of steering information from a torque overlay system (TOS). Based on the set of steering information, a power may be provided to a variable pump motor. The power provided to the variable pump motor may correspond with a speed of a hydraulic pump associated with a power steering gear of the vehicle. As new or additional steering information is received from the TOS, the ECU may adjust the power provided to the variable pump motor.

A vehicle includes a rear steering system and a front differential hydraulic drive system. A first front drive control valve is operable to output a defined fluid flow in response to a steering command input. A second front drive control valve is operable to selectively divert a portion of the defined fluid flow output from the first front drive control valve. When the vehicle is operating in a pre-defined condition, a steering controller may control the second front drive control valve to divert a portion of the defined fluid flow from the first front drive control valve to define a reduced fluid flow, which is communicated to the front differential hydraulic drive system, to reduce a steering ratio of the front differential hydraulic drive system relative to the rear steering system, to desensitize steering provided by the front differential hydraulic drive system.

A vehicle includes a rear steering system and a front differential hydraulic drive system. A first front drive control valve is operable to output a defined fluid flow in response to a steering command input. A second front drive control valve is operable to selectively divert a portion of the defined fluid flow output from the first front drive control valve. When the vehicle is operating in a pre-defined condition, a steering controller may control the second front drive control valve to divert a portion of the defined fluid flow from the first front drive control valve to define a reduced fluid flow, which is communicated to the front differential hydraulic drive system, to reduce a steering ratio of the front differential hydraulic drive system relative to the rear steering system, to desensitize steering provided by the front differential hydraulic drive system.

The disclosure relates to a steering control device and method. A steering control device according to the disclosure comprises a receiver receiving a motor torque from a motor torque sensor provided in a host vehicle and a controller enabling a steering gear to be driven in a compliance zone, calculating a friction of the steering gear based on the motor torque received by the driving of the steering gear, determining a state of the steering gear based on the calculated friction, and outputting, to a driver, a notification message for the state of the steering gear.

A method of steering steerable wheels of a vehicle includes determining a first angle of a first portion of a steering column. A second angle of a second portion of the steering column is determined. The first and second angles are compared to determine a difference between the first and second angles. The vehicle is steered autonomously if the difference between the first and second angles is above a predetermined amount and a time that the difference between the first and second angles is above the predetermined amount is greater than a predetermined amount of time.

Hydraulic bi-directional flow switches are disclosed. A disclosed example apparatus includes a piston disposed in a fluid channel between a first fluid connection and a second fluid connection, where the first and second fluid connections define a fluid pathway for hydraulic steering fluid. The example apparatus also includes a detector to detect a movement of the piston away from a default position of the piston, where the piston is to displace from the default position when the hydraulic steering fluid flows along the fluid pathway.

A self-centering double ended hydraulic steering cylinder that uses no electronics and a method of making the same. The self-centering double ended hydraulic steering cylinder has an elongated housing having end caps at opposing ends of the housing, wherein first and second rod portions are slidably disposed through the end caps. A piston is slidably disposed within the housing, the first and second rod portions extending from the piston, the piston defining first and second hydraulic fluid chambers within the housing. On each opposing end cap is a coiled spring for urging the piston toward a neutral position with the housing. A miniscule passage is formed into the piston so that hydraulic fluid flow through the piston that allows the springs to push the piston back to the neutral position.

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.