Abstract: A rotary-wing aircraft and system for flying a rotary-wing aircraft. The aircraft includes a servo system for actuating a rotor of the aircraft. A hydraulic system provides hydraulic power to the servo system, and a sensor measures a parameter of the hydraulic system. A processor determines a condition of the hydraulic system from the parameter and enforces an effective flight envelop based on the condition of the hydraulic system in order to fly the aircraft within the effective flight envelope.

Abstract: A hydraulic system of a vehicle includes a first pump for supplying at least one first hydraulic circuit and at least one second pump for supplying at least one second hydraulic circuit with hydraulic medium. The second pump supplies the first hydraulic circuit with hydraulic medium in an emergency mode or when an output pressure of the first pump fails.

Abstract: A steer-by-wire steering system for a motor vehicle is proposed, having a steering means which is attached to a steering column, the length and/or inclination of which can be adjusted, and having a steering means actuator which is configured to load the steering means with a torque. The steering means actuator is arranged non-displaceably and fixedly on the vehicle. The steering means actuator is assigned a first shaft, and the steering column is assigned a second shaft, the first and the second shaft having a variable axial offset and/or a variable angular offset at least over a part range of a length and/or inclination adjustment of the steering column. The first and second shafts are connected in a torque-transmitting manner via a compensation device which can compensate for a change in the axial offset and/or the angular offset.

Abstract: The disclosure relates to a steering control system useful for providing stable control during high-speed operation of harvesters, such as self-propelled windrowers. The steering control system utilizes sensors for detecting a ground drive wheel speed or a swash plate position of hydraulic pumps for determining an angle of curvature used as input for controlling a steering cylinder associated with a first caster.

Abstract: A work vehicle includes an engine mounted on a traveling body, a straight-traveling system transmission path including a first stepless transmission device, and a turning system transmission path including a second stepless transmission device, the work vehicle being configured to combine outputs of the straight-traveling system transmission path and an output of the turning system transmission paths to drive left and right traveling units. The work vehicle also includes control sections that control the outputs of the straight-traveling system transmission path and the output of the turning system transmission paths in cooperation with each other, a transmission operation tool that specifies the output of the straight-traveling system transmission path, and a detector that detects the output of the straight-traveling system transmission path.

Abstract: The invention relates to a hydraulic steering device that hydraulically connects a steering cylinder to a supply system, whereby the supply system is hydraulically operatively connectable to the steering cylinder via a steering valve to form a main flow connection and the supply system is hydraulically operatively connectable to the steering cylinder via a flow regulation valve arrangement to form a branch flow connection that circumvents the main flow connection, whereby the flow regulation valve arrangement is triggerable by an electric control unit and the flow regulation valve arrangement comprises valve groups that are triggerable individually, which are respectively connected in the forward flow and return flow of the branch flow connection and a release-shutoff valve is assigned to the flow regulation valve arrangement. It is provided that the release-shutoff valve is connected between the flow regulation valve arrangement and the steering cylinder.

Abstract: A hydraulic circuit for a pair of cylinders of an articulation system includes a pump, a reservoir, a directional control valve (DCV), a pair of actuator valves (AVs) and an articulation charge circuit (ACC). The DCV is fluidly coupled to the pump, the reservoir and the pair of cylinders via a supply line, a fluid return line and a pair of cylinder supply lines (CSLs) respectively. Each CSL has a load check valve (LCV) therein. The AVs are fluidly coupled with the DCV and the pump via a pilot supply line (PSL) for actuating movement of the DCV. The ACC, associated with the PSL and each cylinder supply line downstream of the associated LCV, charges a corresponding CSL with fluid from the PSL for increasing a pressure in the corresponding CSL when the pressure in the corresponding CSL falls below the pressure of fluid associated with the PSL.

Abstract: The present invention relates to a hydraulic steering system for a vehicle, in particular an industrial truck, comprising: a steering cylinder having two chambers and a hydraulic connection at each of the two chambers for activating a steering movement of at least one wheel of the vehicle; at least one hydraulic pump; at least one hydraulic tank for receiving hydraulic oil; and a steering block which comprises: two first hydraulic connections for connecting to the two hydraulic connections of the steering cylinder; at least two second hydraulic connections for supplying hydraulic oil from the hydraulic pump to the steering block and feeding the hydraulic oil back into the hydraulic tank; and a controllable valve assembly which receives control signals from a steering angle detection device and is designed to convey hydraulic oil to the steering cylinder on the basis of said control signals; the controllable valve assembly being further designed to be shiftable into at least one neutral position in which it al

Abstract: Self-propelled vehicles that include swiveling caster wheels and independent drive wheels are disclosed. The self-propelled vehicles are selectively steered in a caster wheel steering mode or a drive wheel steering mode. The vehicle includes a steering position sensor to measure the position of the steering system. A control unit varies the rotational speed of first and second drive wheels based at least in part of the signal from the steering position sensor.

Abstract: An apparatus for use in turning steerable vehicle wheels includes first and second pumps driven by a vehicle engine to supply fluid under pressure to a power steering motor assembly connected with the vehicle wheels. The first pump is sized to provide a fluid flow required by the power steering motor assembly to effect a first vehicle maneuver when the engine speed is at or above a first predetermined speed. A valve directs fluid flow from the second pump to the power steering motor assembly, which when combined with the fluid flow of the first pump is sufficient for the power steering assembly to effect a second vehicle maneuver when the engine speed is at or above the first predetermined speed. A greater fluid flow is required to effect the second vehicle maneuver than to effect the first vehicle maneuver.

Abstract: A vehicle is provided. The vehicle may include an engine that is configured to auto-stop and auto-start. The system may also include a controller programmed to power an electrical actuator coupled to a steering mechanism to synchronize a drive angle of the vehicle and a steering wheel angle of the vehicle, in response to a parameter indicative of a likelihood of a wheel slip event exceeding a threshold and the steering-wheel angle being greater than a predetermined threshold.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A hydraulic control system for vehicles is provided. A switching valve (34) that is adapted to provide a communication between an electric oil pump (25) and a drain passage while inhibiting a delivery of the oil from the electric oil pump (25) to the control object (20, C) when an output pressure of the mechanical oil pump (9) is higher than a predetermined level, and to provide a communication between the electric oil pump (25) and the control object (20, C) through a predetermined oil passage when an output pressure of the mechanical oil pump (9) is lower than the predetermined level. The electric oil pump (25) discharges oil before establishing the communication between the electric oil pump (25) and the control object (20, C) as a result of reduction in the output pressure of the mechanical oil pump (9) to be lower than the predetermined level.

Abstract: An independent steering mechanism of controllable hydraulic locking type for left and right wheels is provided. The independent steering mechanism includes a power steering mechanism, a steering drive mechanism, a hydraulic locking mechanism and an electronic control unit. Power of the left and right steering motors flows through the worm, the worm gear, the gear to drive left and right racks to translate. Outer ends of the left and right racks are connected to left and right tie rods via spherical hinges respectively. Inner ends of the left and right racks are connected to a piston rod and a cylinder barrel via spherical hinges respectively. A left chamber and a right chamber in the hydraulic cylinder are connected to an oil reservoir via an electro-hydraulic valve. The left and right steering motor controllers for the left and right steering motor and the electro-hydraulic valve controller are communicated via CAN bus.

Abstract: A method to control a road vehicle with steering rear wheels when driving along a curve. The control method comprises the steps of: determining an actual attitude angle of the road vehicle; determining a desired attitude angle; and changing the steering angle of the rear wheels based on the difference between the actual attitude angle and the desired attitude angle.

Abstract: Delivery ports of a closed circuit hydraulic pump are connected to a head-side chamber and a rod-side chamber of an arm/boom cylinder. A switching valve is arranged between the head-side chamber and a delivery port of an open circuit hydraulic pump. A proportional control valve is arranged between the head-side chamber and a hydraulic fluid tank. At times of cylinder extension, both of the closed and open circuit hydraulic pumps and the switching valve are controlled so that the delivery flows from the closed and open circuit hydraulic pumps are sent to the head-side chamber. At times of cylinder retraction, the closed circuit hydraulic pump and the proportional control valve are controlled so that part of an outward flow from the head-side chamber is returned to the closed circuit hydraulic pump and other part of the outward flow is returned to the hydraulic fluid tank.

Abstract: A vehicle adaptive steering control apparatus includes a front wheel steering mechanism having a right wheel steering portion and a left wheel steering portion. A left front wheel rotatably is coupled to the left wheel steering portion. A right front wheel rotatably coupled to the right wheel steering portion. A controller in electronic communication with a steer-by-wire steering wheel assembly and the front wheel steering mechanism operates the front wheel steering mechanism to turn the left front wheel and the right front wheel in accordance with Ackerman steering geometry. The controller is also configured to calculate toe angle adjustments for the right wheel steering portion relative to the left wheel steering portion and make the toe angle adjustments to right wheel steering portion and the left wheel steering portion during turning and steering movements effected by the right wheel steering portion and the left wheel steering portion.

Abstract: A steering system for a work vehicle includes a steering hand pump, a hydraulic main supply line fluidly coupled with the steering hand pump and including a check valve, and a normally open, two position valve. The valve includes an inlet fluidly couplable with a pressurized access point of a hydraulic sub-system, an outlet fluidly coupled with the main supply line on a downstream side of the check valve, and a pilot port fluidly coupled with the main supply line on an upstream side of the check valve. The valve is operable in the closed position based on pressure in the main supply line when the main supply line is pressurized from a pressure source, and operable in the open position and interconnecting the pressurized access point with the main supply line through the outlet when the main supply line is not pressurized from the pressure source.

Abstract: A method for controlling steering of a vehicle (1) is provided, the vehicle (1) defining two or more steerable axes, and the vehicle (1) comprising a number of wheels (2), each of said wheels (2) being associated with one of said steerable axes in such a manner that steering of a given wheel (2) is obtained by steering the steerable axis associated therewith. The method comprises providing a first, a second and a third steering input. The first steering input defines a point of intersection between a virtual steering axis (4) and a longitudinal center axis defined by the vehicle (1). The second steering input defines an angle between the virtual steering axis (4) and the longitudinal center axis. The third steering input defines a position of a center of rotation (5) along the virtual steering axis (4).

Abstract: A power steering system includes an EPS and a HPS. At normal times, an assist force required by a steering system is computed based on a steering torque and a vehicle speed, and the required assist force is generated by the EPS and the HPS. The torsional stiffness of a torsion bar of the HPS is equal to or substantially equal to the torsional stiffness of a torsion bar of the EPS. Therefore, even if the EPS malfunctions, it is possible to gain the steering feel similar to that when the EPS is operating properly.

Abstract: A steering system for an autonomous vehicle includes a steering mechanism having a pinion gear and a rack, the steering mechanism being configured to translate rotation of the pinion gear into movement of the rack which is configured to affect the position of a steer tire of the autonomous vehicle, thereby affecting the lateral position of the autonomous vehicle; a steering wheel which provides a mechanical input to the pinion gear from an operator of the autonomous vehicle; a steering actuator which rotates to apply torque to the steering mechanism, thereby inducing movement of the rack which affects the position of the steer tire of the autonomous vehicle; and a variable coupling member operatively between the steering actuator and the steering mechanism which is configured to vary the torque that can be transmitted from the steering actuator to the steering mechanism.

Abstract: A steering stop for a steer-by-wire steering system, includes a steering shaft for functionally connecting to a steering wheel, wherein a pressure chamber is provided for each direction of rotation of the steering shaft. A rotation of the steering shaft produces a reduction in the volume of a corresponding pressure chamber, and the steering stop also comprises a hydraulic valve such that resistance against a further rotation of the steering shaft is generated by the operation of said hydraulic valve when predetermined environmental conditions are met.

Abstract: A vehicle steering system includes: a steering wheel having the capacity to steer a vehicle; a turning actuator having the capacity to turn a wheel; a backup clutch arranged between the steering wheel and the turning actuator and having the capacity to be able to mechanically connect the steering wheel to the turning actuator; and a clutch disengagement checking unit having the capacity to check whether the backup clutch is disengaged.

Abstract: A steering system is described for a vehicle having steerable wheels. A hydraulic charge pressure circuit may be configured to provide charge pressure to one or more hydraulic components of the vehicle, and a hydraulic drive pressure circuit may be configured to provide working pressure to one or more other hydraulic components of the vehicle. Hydraulic machines may rotate front wheels in order to drive the vehicle, and a front valve assembly may control steering of the front wheels by controlling the hydraulic machines. The hydraulic machines may be driven to rotate the front wheels by the working pressure from the hydraulic drive pressure circuit, and the front valve assembly may control the front hydraulic machines to steer the agricultural vehicle by controlling flow of hydraulic fluid from the hydraulic charge pressure circuit through the front valve assembly.

Abstract: A vehicle steering system includes: a steering wheel having the capacity to steer a vehicle; a turning actuator having the capacity to turn a wheel; a backup clutch arranged between the steering wheel and the turning actuator and having the capacity to be able to mechanically connect the steering wheel to the turning actuator; and a clutch disengagement checking unit having the capacity to check whether the backup clutch is disengaged.

Abstract: There is disclosed a steering system for a vehicle. The system comprises a rotatable steering column co-operable with a steering wheel. A steering member is co-operable with the steering column such that rotary motion of the steering column causes linear motion of the steering member and linear motion of the steering member causes rotary motion of the steering column. An actuator is co-operable with the steering member for linear actuation of the steering member, the actuator being configured for receiving and executing commands from a controller that sends, in dependence on a defined condition, an oscillation command to the actuator to impart an oscillating force to the steering member. A method of providing feedback through a steering system of a vehicle is also disclosed, as are suitable controllers, software and processors.

Abstract: A combination sensor module for a vehicle, having at least two sensor submodules which are situated in the combination sensor module and able to be connected to the electronics system of the vehicle, wherein the at least two sensor submodules are able to be operated independently of each other.

Abstract: The invention concerns a hydraulic steering arrangement with a hydraulically actuated steering valve arrangement, steering motor connections (CL, CR), which are connected to supply connections (HP, T) via the steering valve arrangement, and a steering unit. It is endeavored to equalize in a simple manner the steering behavior in both directions. For this purpose, it is ensured that the steering valve arrangement has a directional valve and a flow control valve.

Abstract: A vehicle drive control system (1), such as a car, a boat, an aircraft and like, or of a driving simulator, such as a videogame console, simulation apparatuses and the like, and with a direction control device (2), such as a steering wheel, a rudder or the like, and with directioning means (21?, 22?, 21?. 22?), said system (1) being characterized by means (6) for detecting a position of said direction control device (2), an adjustment module (7, 7?, 7?) having a frame, mechanically coupled with said direction control device (2), provided with passive actuator and adjustment means (8?, 8?, 8a, 8a?, 8b, 8b?) to adjust resistance to the movement of said direction control device (2), one or more sensors (27) for detection of position of said directioning means (21?, 22?, 21?. 22?), and at least a central control unit (23).

Abstract: A steering method for an industrial truck includes manually steering at least one steerable wheel, detecting an angular position of the at least one steerable wheel, and motor-steering at least one additional steerable wheel as a function of the detected angular position. For a 90° change of a travel direction of the industrial truck, the method comprises steering the at least one steerable wheel and the at least one additional wheel by 90°, manually steering the at least one additional wheel, and motor-steering the at least one steerable wheel.

Abstract: An integrated steering control system includes a primary, automatic and rear control valves. A steering wheel operates the primary steering control valve and is of a type which includes a leakage characteristic. Steering wheel movement is sensed and a signal is sent which results in the automatic steering control valve being operated for adding fluid that supplied to a steering cylinder by the primary steering control valve in order to compensate for leakage, the amount of added fluid being a function of vehicle ground speed. An electric actuator with position feedback is used for ground speed control. Whenever the actuator position shows that the ground speed is set to zero and a switch in the hydro-handle slot shows that the handle is in the Park position, the automatic steering control valve is activated to move the steering cylinder to a neutral, straight ahead position, as determined by a sensor in a mechanical linkage of the steering control.

Abstract: An electric power steering apparatus that is capable of obtaining a more safe and comfortable handling performance by signal processing of road information and disturbances is performed to realize easy tuning, and vibration absorption level for brake is improved by a filter and a gain unit considering a frequency characteristic and a decelerating acceleration.

Abstract: The invention relates to a steering system for a motor vehicle, comprising a steering wheel, a steering gear shaft and a hydraulic master unit, the steering gear shaft being in mechanical active connection with the master unit via a toothing, and also comprising hydraulic lines and a hydraulic slave unit in a steering gear which, for swivelling steerable wheels is mechanically coupled therewith, an electronic control for controlling an electric servomotor being provided which is actively connected to the steering gear, the active connection between the steering shaft and the hydraulic master unit being a toothing with a variable transmission.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. An engine driven pump connected with the power steering motor assembly is driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly. A controller increases engine speed when the vehicle is motionless and a steering wheel is rotated. A method for controlling the speed of an engine to provide a predetermined steering assist to a steering apparatus includes determining if the vehicle is motionless and determining if the steering wheel is being rotated. The speed of the engine is increased if the vehicle is motionless and the steering wheel is being rotated to provide the predetermined steering assist to the steering apparatus.

Abstract: A two-phase motor with high space utilization efficiency is provided for driving a hydraulic control valve. A valve drive motor includes a rotor and a stator surrounding the rotor. The rotor has six magnetic poles. The stator includes six stator windings. The U-phase first stator winding and the V-phase first stator winding constitute a pair of two-phase stator windings. The U-phase second stator winding and the V-phase second stator winding constitute a pair of two-phase stator windings. The U-phase third stator winding and the V-phase third stator winding constitute a pair of two-phase stator windings. The two stator windings of each pair are disposed at an angular interval of 180 degrees in terms of an electrical angle.

Abstract: A hydraulic power steering system controllable by left and right steering wheels has two control valves, each valve connected to a respective left and right steering wheel, and a valve arrangement that selectively connects one control valve to a source of high-pressure fluid and disconnects the other control valve from the source of high-pressure fluid.

Abstract: A steering device for a wheel loader includes a rotatable handle, a tiltable lever, a steering cylinder, a steering valve, a pump, a handle control valve, a lever control valve, and a handle prioritization valve. The steering valve controls a supply direction of operating fluid to the steering cylinder with pilot hydraulic pressure. The pump supplies operating fluid to the steering cylinder via the steering valve. The handle and lever control valves supply pilot hydraulic pressure to control the supply direction to the steering valve according to handle rotation and lever tilt, respectively. The handle prioritization valve shuts off the pilot hydraulic pressure supplied from the lever control valve to the steering valve according to a differential pressure or an absolute pressure in a hydraulic circuit produced due to operating fluid flowing through the handle control valve when the handle is operated.

Abstract: A steering system can include a steering control valve, primary and secondary sources of pressurized fluid, and a controller. The primary and secondary sources of pressurized fluid can be fluidly connected to the steering control valve. The primary source of pressurized fluid can be configured to sense a load pressure requirement from the steering control valve. The controller can be communicably coupled to the primary and secondary sources of pressurized fluid. The controller can monitor a margin pressure of the primary source of pressurized fluid. The controller can determine an operational status of the primary source of pressurized fluid based on the monitored margin pressure.

Abstract: A ring-mount joint between two vehicle units of an articulated bus, with the joint comprising two cantilevers, wherein each cantilever is arranged on one of the vehicle units, with each cantilever comprising a slewing ring, wherein the two slewing rings of the cantilever are mounted in each other so that they can be pivoted, wherein a damping device is provided for damping the rotational motion of the two cantilever relative to each other, wherein in the space enclosed by the inner slewing ring, there is arranged an annular chamber damper, wherein the annular chamber damper comprises two inter-mounted housing parts that are rotatable relative to each other, wherein the one housing part is in connection with the one cantilever and the other housing part is in connection with the other cantilever.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (14, 16) includes a hydraulic power steering motor (12). A pump (26) having an outlet port (28) is connected in fluid communication with the power steering motor (12) and operable to supply hydraulic fluid to the power steering motor (12). A continuously variable transmission (50) is connected with the engine of the vehicle and the pump (26). The continuously variable transmission (50) is operable to drive the pump (26) at a first speed when the pressure at the outlet port (28) is at a first pressure. The continuously variable transmission (50) is operable to drive the pump (26) at a second speed when the pressure at the outlet port (28) is at a second pressure different than the first pressure. The first speed at which the pump (26) is driven is greater than the second speed.

Abstract: A steering system includes a steer-by-wire (SBW) valve, a main steering pump, a steering actuator, and a steering control unit (SCU). The SCU is in fluid communication with the actuator via a pair of fluid conduits, and includes upper and lower portions. The upper portion contains a first solenoid valve and a cross-over check valve assembly. The lower portion contains a fluid control valve. An ECU generates a steering input signal in response to steering wheel rotation, and transmits the signal to the SBW valve. The SCU controls the first solenoid valve to deliver fluid from the lower portion to the actuator via the cross-over valve assembly in an emergency steering mode, and also controls the first solenoid valve to prevent flow into the actuator and allow recirculation of fluid within the lower portion in a torque feel mode.

Abstract: Embodiments of the invention provide a computer program product embodied on a computer readable storage medium. The computer program product is encoded with instructions configured to control a controller to perform a process. The process includes setting a target steering angle for the vehicle based on a steering amount of the vehicle, setting a target torque difference between right and left steered wheels based on the target steering angle, and setting a target driving/braking force for the vehicle based on an acceleration amount and a braking amount of the vehicle. The process also includes setting each target torque for the right and left steered wheels based on the target torque difference and the target driving/braking force and controlling driving of the steered-wheel motors based on the target torque. The kingpin point is positioned closer to the vehicle on an inside portion of an inside sidewall of a steered wheel.

Abstract: The present invention provides a steering control apparatus that controls steering of a vehicle of a steer-by-wire type, and includes steered-wheel motors that apply separate torques to right and left steered wheels respectively, a rod member that couples the right and left steered wheels so that the steered wheels can be steered, and a steering controller that controls driving of the steered-wheel motors. In each steered wheel, a center of the contact face thereof and a kingpin point thereof are offset in a lateral direction of the vehicle, and the steering controller controls driving of the steered-wheel motors so as to generate a torque difference between the right and left steered wheels, and provides a steering effort in accordance with this torque difference for each of the right and left steered wheels via the rod member, thereby to steer the vehicle.

Abstract: A vehicle by-wire steering system includes a hydraulic default level. A hydraulic feed unit and a hydraulic actuating unit can be connected together by two hydraulic lines such that when an actuator is non-functional, a steering wheel rotational angle is transformed into a corresponding wheel steering angle by the hydraulic feed unit and the hydraulic actuating unit. The hydraulic lines can be connected together by a switchable steering valve, which is designed as a proportional servo valve, of which the flow cross section can be adjusted in essence continuously between the two extremes of completely closed and completely open.

Abstract: A center-closed power steering system provides power steering assistance in engine-off conditions for reduced fuel consumption. The power steering system includes a hydraulic pump mechanically driven by the engine, a high pressure accumulator, a steering gearbox fluidly connected to the accumulator, and a center closed valve mechanically connected to a driver-operated steering wheel. The valve is configured to selectively control flow of pressurized fluid from the accumulator to the steering gearbox to provide power steering assistance. The inner shaft of the rotary center-closed valve is provided with a cavity with V-shaped notches on the transition surfaces on lands configured to sealingly engage the inner surface of the valve outer sleeve, in order to provide a smooth transition in flow for power steering assistance, and a better driver feel.

Abstract: A steering system, comprising: an input cylinder having a first hydraulic chamber and a second hydraulic chamber; a transmission mechanism, wherein a transmission efficiency for converting and transmitting a linear motion of the input cylinder to a rotary motion of a steering wheel is less than a transmission efficiency for converting and transmitting the rotary motion of the steering wheel to the linear motion of the input cylinder; an output cylinder connected to a steerable vehicle wheel and having a third hydraulic chamber and a fourth hydraulic chamber; a first hydraulic passage for connecting the first hydraulic chamber to the third hydraulic chamber; a second hydraulic passage for connecting the second hydraulic chamber to the fourth hydraulic chamber; a flow rate control mechanism for exchanging hydraulic oil with: a first hydraulic circuit including the first and third hydraulic chambers and the first hydraulic passage; and a second hydraulic circuit including the second and fourth hydraulic chambers

Abstract: The invention concerns a hydraulic steering (1) with a steering valve (7) located between a supply connection arrangement (P, T) and a steering motor (2). It is endeavored to improve the safety of such a steering. For this purpose, the steering valve (7) has a hydraulic drive (9, 10) with a pilot valve arrangement (11) supplied by a pressure control valve (5), a stop valve (16) being located between the pressure control valve (5) and the pilot valve arrangement (11).

Abstract: The invention concerns a hydraulic steering (1) with a supply connection arrangement (P, T), a steering motor (2) and a steering unit (3) between the supply connection arrangement and the steering motor (2), the steering unit (3) having a directional section (4) and a measuring section (5), a steering valve (9) being arranged in parallel to the steering unit (3). With such a steering, it is endeavored to achieve the best possible safety. For this purpose, it is ensured that for each steering direction the directional section (4) comprises a first outlet (A1L, A1R), which is connected to the steering motor (2) by means of a first pipe (23, 24), and a second outlet (A2L, A2R), which is connected to the steering motor (2) by means of a second pipe (25, 26), the first outlet (A1L, A1R) being, in the neutral position of the directional section (4), connected to the measuring section (5), and the first pipe (23, 24) being interruptible by means of a valve arrangement (27, 27a).

Abstract: A steering system is provided for controlling the turning angle of the steering wheels of a vehicle. The steering system includes two electro-hydraulic circuits each including an actuator, both actuators being mechanically coupled and acting simultaneously on the turning angle of the wheels. A first circuit is displacement-controlled relative to a position set point while a second circuit is stress controlled. The set point applied of the second circuit includes a component developed from the filtering of the position set point applied to the first circuit.

Abstract: An all terrain vehicle has a frame carried by a group of wheels. At least one of the wheels is steerably connected to the frame. A steering handle assembly is rotatably connected to the frame. A servo valve has an input shaft connected to the steering handle assembly and an output shaft connected to a pitman arm. A linkage extends from the pitman arm to the steerable wheel or wheels. A pump draws fluid from a reservoir and passes the fluid through the servo valve before the fluid is returned to the reservoir. The servo valve redirects at least a portion of the flow to a cylinder to drive a ram within the cylinder in response to steering movement of the steering handle assembly. The ram, in turn, provides a power assist to the steerable wheel or wheels. A variable speed, constant displacement pump can be used to vary the flow rate in a manner that reduces the flow rate as the vehicle speed increases. Alternatively, a bypass can be used to vary a flow rate through the servo valve.