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 linear solenoid is configured with an electromagnetic coil and a label resistor that are integrated with each other; the label resistor has a resistance value corresponding to a correction coefficient based on the difference between the actual characteristic of the supply current vs. adjusted hydraulic pressure output of the electromagnetic coil and a standard characteristic; and data for correcting a characteristic variation in the command current vs. output current characteristic of an electromagnetic coil is preliminarily stored in a control module by use of an adjustment tool. When the operation is started, the resistance value of the label resistor is read and an output current corresponding to a utilized linear solenoid is supplied, so that a target adjusted hydraulic pressure is obtained.

Abstract: In a stroke-limiter equipped integral power steering apparatus, a valve body of a spring-loaded-plunger-equipped limiter valve is configured to enable a position of the valve body relative to a housing to be adjusted in a longitudinal direction of the valve body via an intermediate sleeve.

Abstract: In order to provide a solenoid valve or solenoid that allows easy and accurate wire winding for an electric annular coil employed therein, a simple shape is possessed by the electric annular coil with inner and outer cylindrical surfaces that entirely extend in parallel with an axis of the electric annular coil and a sleeve for axially sliding therein an armature together with a plunger is shaped to have a larger diameter portion that is put between a smaller diameter portion of a front core and the inner cylindrical surface of the electric coil, a smaller diameter portion that is put between the armature and a rear core integral with a solenoid housing and a sloped annular intermediate portion that extends between the larger and smaller diameter portions.

Abstract: A hydraulic power steering system for a ground vehicle includes a closed-center control valve, a fluid supply line and an exhaust line extending into the control valve and first and second motor lines extending out of the control valve to a fluid motor. An additional flow line extends from each motor line to the exhaust line and contains a check valve that allows flow in the flow line only towards the motor line. The additional flow lines enable manual steering in the event fluid supply is lost without leakage loss during normal on center operation.

Abstract: A pinion valve body and a vehicle pinion valve assembly with the valve body are disclosed. The pinion valve body has a lower sleeve integrally formed by a sintering process along with upper splines to block an oil leakage and thus there are no needs any more for the conventional separate lower sleeve as well as the associated machining of sleeve fitting areas on the valve body and the process of press-fitting such sleeve all together, thereby effectively reducing the general manufacturing steps and their cost.

Abstract: An integral power steering apparatus includes a hydraulic actuator having a piston separating pressure chambers for steering assistance and a limiter valve to be opened by movement of the piston to fluidly connect the pressure chambers. The limiter valve includes an adjuster for adjusting a press-fit position of a spring pin press fit in a plunger. The adjuster includes a movable adjusting member formed with an abutting surface to abut against the plunger to limit rearward plunger movement when the movable adjusting member is at a first adjuster position, and a regulating member to hold the movable adjusting member at the first adjuster position at the time of adjustment, and to enable the movable adjusting member to move to a second adjuster position after adjustment.

Abstract: A steering system includes a fluid actuator, a first steering circuit in selective fluid communication with the fluid actuator, and a second steering circuit in selective fluid communication with the fluid actuator and disposed in parallel to the first steering circuit. The second steering circuit includes a load-reaction feature and an isolation valve with the isolation valve being adapted to enable and disable the load-reaction feature.

Abstract: In a steering operation device, a hydraulic actuator is driven by hydraulic pressure and vary the steering angle of the vehicle. A steering valve adjusts the flow rate of oil supplied to the actuator according to a pilot pressure. A pilot valve adjusts the pilot pressure input to the steering valve according to a difference between a displacement of an operation input shaft and a displacement of a feedback input shaft. A joystick lever is linked to the operation input shaft and moves the operation input shaft according to a tilt angle. A drive device displaces the feedback input shaft. A steering angle sensor detects the steering angle and outputs the angle as a detected signal. A controller sends a command signal to the drive device so as to displace the feedback input shaft according to the detected steering angle.

Abstract: A hydraulic steering control valve, including a valve core. When an automobile runs in a straight line or the steering angle is maintained, the valve core of the hydraulic steering control valve is positioned in a middle position to cut off hydraulic pipelines of oil cylinders on two sides of a steering power cylinder or a hydraulic shock-absorbing part, and a piston of the steering power cylinder or the hydraulic shock-absorbing part is unable to move. A self-aligning mechanism is arranged at an input shaft end of the hydraulic steering control valve, and after a driver eliminates the steering torque and loosens the control to a steering wheel, the self-aligning mechanism drives the input shaft or the steering wheel to turn to the middle position, so as to fulfill the self-aligning function.

Abstract: The invention relates to a slide vane (20) for a hydraulic power steering of automotive vehicles with a tubular control sleeve (24). Said control sleeve is connected to an output shaft (28) and comprises first control grooves (32) in its inner surface (34). Further, there is provided a tubular sliding sleeve (26) that is disposed at least in portions within said control sleeve (24). On its outer surface (38), the sliding sleeve (26) comprises second control grooves (36) that may be brought to coincide with the first control grooves (32) of the control sleeve (24), said first control grooves (32) being disposed substantially in the circumferential direction of the tubular control sleeve (24) and said second control grooves (36) substantially in the circumferential direction of said tubular sliding sleeve (26). The relative position of said control sleeve (24) and of said sliding sleeve (26) being relatively variable in the axial direction.

Abstract: A hydraulic steering system for a vehicle includes a first steering member and a second steering member, wherein the first steering member is operationally connected to a first steering valve unit including a first steering valve, and wherein a priority valve controls a flow of a hydraulic fluid to one or more steering cylinders which provide for steering of the vehicle in a desired steering direction, wherein the priority valve gives priority to steering with the first steering member over the steeling with the second steering member. A second steering valve is provided functionally operable in series with a proportional flow control valve, wherein the second steering valve and/or the proportional flow control valve are controlled at least by the second steering member.

Abstract: A hydrostatic steering system has a steering cylinder for coupling to steerable wheels, a gerotor pump, a steering valve and an actuator controlled mode select valve. The steering valve is mechanically and hydraulically coupled to the gerotor pump, and controls fluid communication between the gerotor pump and the steering cylinder. The steering valve has a center position wherein communication between the gerotor pump and the steering cylinder is closed. The actuator controlled mode select valve controls fluid communication between the gerotor pump and the steering cylinder independently of the steering valve.

Abstract: The present invention relates to a steering device for a self-propelled construction or utility machine. The construction or utility machine includes a cab having a carriage, which is adjustable transversely to the travel direction, on which operating and/or actuating elements and at least one steering wheel for steering the construction or utility machine are situated. The steering wheel is coupled via a steering drive shaft, which is mounted on the adjustable carriage, and is carried along upon adjustment, to a steering output shaft, which is situated fixed in place on the construction or utility machine and runs transversely to the steering drive shaft.

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: There is provided a circulation line (39) for circulating pressurized oil from an accumulator (11) into a housing (15) of a steering valve (14). An orifice joint (41) is provided along the path of the circulation line (39). The orifice joint (41) is removably mounted on the housing (15) of the steering valve (14) from outside. An orifice portion (42) of the orifice joint (41) applies a throttling function to the circulating oil liquid whereby a frictional heat is generated therein. The oil liquid in a warm state flows through a communication passage (21), passages in a spool valve (16), and a low pressure side passage (18B), thus enabling the steering valve (14) to be always in a warm state.

Abstract: The invention concerns a hydraulic steering with a steering initiator, a steering unit with feedback properties, which can be activated by the steering initiator, the steering unit having a supply connection arrangement with a pressure connection (P) and a tank connection (T) and a working connection arrangement with two working connections (L, R), an auxiliary-force operated steering valve, which is located in parallel with the steering unit between the supply connection arrangement (P, T) and the working connection arrangement (L, R), and a feedback suppressing device, which is active, when the steering valve is active. It is endeavored to find a simple manner of ensuring the priority of the steering initiator over the steering valve. For this purpose, the steering initiator interacts with an activation sensor, which deactivates the feedback suppressing device on an activation of the steering initiator.

Abstract: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

Abstract: A steering control system for directing fluid to steering actuators on a machine include a set of right and left manually-operated pilot pressure fluid control valves and a set of right and left electro-hydraulic (EH) pilot pressure fluid control valves, with both sets being coupled to a main steering control valve for controlling movement of the latter to effect operation of the steering actuators.

Abstract: In a hydraulic power steering system with a steering gear and a hydraulic actuator for supporting a steering wheel actuation by the driver of a vehicle including a device for actively applying an additional steering torque, is disclosed. The device for actively applying an additional steering torque includes at least one additional torque actuator and a detector for detecting the steering torque, and the detector detects a hydraulic pressure.

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: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

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 power steering system for a vehicle is described, wherein a magnetic or electromagnetic actuator, which can be acted on via a controller, is associated with a torsion bar connected to a steering wheel, and by which the torsional stiffness of the system is variable in dependence on the vehicle speed, the steering angle speed and/or the transverse acceleration. In this connection, the electrical power supply of the magnetic or electromagnetic actuator taking place via the controller is interrupted or reduced when a steering angle speed of zero is detected or when a steering angle speed of zero and a vehicle speed of zero are detected.

Abstract: The invention relates to a hydrostatic steering system. There is a need for such a system which can easily be switched between non-load reactive and load reactive modes. A steering system is provided which has a steering cylinder for coupling to steerable wheels, a gerotor pump, a steering valve and an actuator controlled mode select valve. The steering valve is mechanically and hydraulically coupled to the gerotor pump, and controls fluid communication between the gerotor pump and the steering cylinder. The steering valve has a center position wherein communication between the gerotor pump and the steering cylinder is closed. The actuator controlled mode select valve controls fluid communication between the gerotor pump and the steering cylinder independently of the steering valve.

Abstract: To provide a steering system for a construction vehicle, which is suited not only for traveling on general roadways but also for work at construction sites and can perform high-reliability steering control. A steering system for a construction vehicle is provided with a directional control valve 5 for controlling a flow of pressure oil to body-articulating hydraulic cylinders 2 that perform steering and also with a steering-wheel-operated signal generation means 6 for outputting by operation of a steering wheel 7a a pilot signal to the directional control valve 5 for switching the valve 5.

Abstract: A pipe/silencer device assembly comprising a connection element, which has a through hole, having an axis, and a branching off hole, which is fluidically connected to the through hole and wherein the assembly comprises: first connection co-operating with a first duct; a second duct, fluidically connected to the connection element; and a blind silencer duct, fluidically connected to the branching off hole.

Abstract: A filter includes top and bottom support frames, and one or more middle support frames, which are arranged in such a manner that a second stepped area recessed by a predetermined depth from the outer circumferential surfaces of the top and bottom support frames is formed by the top and bottom support frames and the middle support frames. A pressure control valve of an electronically controllable power steering apparatus includes: a hollow valve body having a first stepped area with a predetermined depth, the first stepped area being formed on the outer circumferential surface of the valve body, where a supply port is formed; and the above-mentioned filter, the filter being fitted in the first stepped area of the valve body. The filter can minimize change of pressure at the filter area while assuring smooth supply of the hydraulic fluid, and can reduce the number of parts, the number of fabricating steps, and the material costs of such a pressure control valve.

Abstract: A multiple-speed steering system for an off-road vehicle having a loading mechanism and a hydraulic steering system associated with guiding the vehicle. The multiple-speed steering system includes a hydraulic steering cylinder and a first component fluidly coupled to the steering cylinder to provide a primary metered flow of hydraulic fluid to the steering cylinder. A second component is selectively fluidly coupled to the steering cylinder to provide a supplemental metered flow in addition to the primary metered flow of hydraulic fluid to the steering cylinder. Addition of the supplemental metered flow is selectable by an operator of the vehicle.

Abstract: A frequency suppressor for a hydraulic system is shown and described. The frequency suppressor comprises a housing that contains a substantially fixed mass of a compressible substance. The volume of the compressible substance is varied to dampen frequency disturbances in the hydraulic system.

Abstract: A control system (201) for a frame-steered vehicle that includes a first steering cylinder (104) and a second steering cylinder (105). The steering cylinders are arranged for frame-steering of the vehicle. The system includes a first drive unit (202) and a second drive unit (204), each of which has an electrical machine (206,208) and a hydraulic machine (210,212). Each respective electrical machine is drivingly connected to its associated hydraulic machine, wherein with a first (210) of the two hydraulic machines is arranged for flow-communication with a piston side (214) of the first steering cylinder (104) and a piston rod side (216) of the second steering cylinder (105). A second (212) of the two hydraulic machines is arranged for flow-communication with a piston side (218) of the second steering cylinder and a piston rod side (220) of the first steering cylinder.

Abstract: A vehicle including a steering system for moving a pair of wheels supported by a wheel support structure relative to a vehicle structure to achieve steering of the vehicle whilst the vehicle is travelling. The system including a pressure source for providing a supply of pressurized fluid through first and second steering valves to fluid operated first and second actuators, each of which includes an actuating member. The steering valves are operator controlled to provide the pressurized fluid, at least when the steering system is in a first operating mode, from both the first steering valve to the first actuator and from the second steering valve to the second actuator to achieve steering. When the steering system is operating in a second operating mode, only one of the first and second steering valves provides pressurized fluid from the source to a respective one of the actuators to achieve steering.

Abstract: A hydraulic power steering system that maintains proportional pressure control between an input side of a gear and assist pressures internal to the steering gear by relying upon a control valve. A pressure differential is maintained between the input side of a gear and assist pressures internal to the steering gear throughout certain events. Those events include running the pump to fully charge the accumulator, idling the pump after fully charging the accumulator, discharging pressure from the fully charged accumulator at an onset of a steering event having a demand for steering load, recovering the discharged pressure of the accumulator by running the pump after turning on the pump at the onset of the steering event, and opening the relief valve in the valve manifold during the steering event.

Abstract: A steering system for an agricultural vehicle with a hydraulic steering motor incorporates an internal pump, a distribution valve, an input shaft which in use is coupled for rotation by the steering shaft of a vehicle steering wheel, and connectors for hydraulic lines leading to a high pressure source of oil, to an oil reservoir and to hydraulic actuators connected to the steerable wheels of the vehicle. The steering motor is located remotely from the steering shaft and is coupled for rotation with shaft by hydraulic rotary actuators mounted on the steering shaft and the input shaft of the steering motor and arranged in a closed circuit with one another.

Abstract: A method of determining a direction of a power boost applied to a power cylinder of a variable effort power steering system includes measuring a pressure of a hydraulic fluid between a pump and a control valve. A first position of the hand wheel is detected and initialized when the pressure is within a pre-defined equilibrium pressure range. A second position of the hand wheel is detected in response to rotational movement of the hand wheel. The first position and the second position of the hand wheel are measured in cumulative degrees rotated left or right of a on-center orientation of the hand wheel. The second position is subtracted from the first position to obtain a differential value representing the direction of the power boost. A negative differential value represents a first direction and a positive differential value represents a second direction of the power boost.

Abstract: The invention concerns a hydraulic steering (1) with a steering unit (2) with feedback behavior, a steering motor (8) connected to the steering unit (2) via working pipes (L, R), a steering member (6) and a feedback suppression device (9), which is located in at least one working pipe (L, R). It is endeavored to change the feedback behavior of such a steering in a simple manner. For this purpose, the feedback suppression device (9) has a valve arrangement (10) with hydraulic control inlet (C).

Abstract: A steering apparatus for vehicle comprises a steering shaft including a first portion connected to a steering member and a second portion connected to steerable wheels; a transmission ratio variable mechanism capable of varying a transmission ratio as a ratio of a steered angle of the steerable wheels to a steering angle of the steering member; and a reaction-force compensation motor for compensating a steering reaction force of the steering member caused by the operation of the transmission ratio variable mechanism. The transmission ratio variable mechanism includes a differential mechanism for differentially rotatably interconnecting the first and second portions; and a differential-mechanism motor for driving the differential mechanism. Both an axis of a rotary shaft of the differential-mechanism motor and an axis of a rotary shaft of the reaction-force compensation motor are aligned with an axis of the steering shaft.

Abstract: A rotary slide valve, in particular for speed-dependent power steering systems in motor vehicles, has a torsion bar, a rotary slide, and a control bushing. The control bushing is pressed onto a pinion and the torsion bar is inserted into a torsion bar bore of the pinion. The control bushing is connected rotation-fast to the pinion by shaping. The torsion bar has teeth that are pressed into the torsion bar bore of the pinion and that connect the torsion bar to the pinion rotation-fast.

Abstract: Disclosed is a hydraulic steering system (100) for a vehicle, especially a mobile working machine, comprising at least two steering cylinders (1, 2) within which two cylinder pistons (3, 4) can be displaced, and a first hydraulic pump (14) that can be adjusted regarding the swept volume. The position or the direction of displacement of the cylinder pistons (3, 4) in the steering cylinders (3, 4) defines the steering angle or the steering direction of the steerable vehicle wheels relative to a body (5) of the vehicle. The displaceable cylinder pistons (3, 4) divide the associated steering cylinder (1, 2) into two respective pressure chambers (6 and 7, 8 and 9).

Abstract: A vehicle system has a steering circuit which includes a steering actuator supplied with pressurize fluid from a pressure source to turn an associated vehicle wheel to the left or right in response to the movement of the steering wheel. A feedback circuit is provided which includes a steering motor connected with the steering wheel and supplied with pressurized fluid via an electronically controlled feedback control valve means in response to signals received from a control unit to generate a steering feedback force acting on the steering wheel.

Abstract: A hydraulic system including a control valve and a steering control assembly. The steering control assembly includes a steering control unit and a priority flow divider contained in a single unitary casing. The steering control assembly is attached adjacently with and directly to the control valve by means of an interface that fluidly connects the control valve with the steering control assembly.

Abstract: In a power steering system comprising a power cylinder for assisting a steering power of a steering mechanism, a hydraulic pump for supplying a hydraulic pressure to the power cylinder, a first oil passage and a second oil passage connecting the power cylinder and the hydraulic pump respectively, a motor for driving the hydraulic pump, and power steering control means for calculating a command value to the motor based on the steering torque, a flow rate of the working oil supplied from a high-pressure side oil passage to a low-pressure side oil passage is restrained at the transition from the end of the steering state (lock end) of the steering mechanism to the returning. The flow-rate restraint increasingly corrects a driving current of the motor in the steering direction or limits the flow rate of the working oil.

Abstract: A valve has a valve body with first and second intake passages, first and second supply passages and a reservoir return passage defined therein. A shuttle member is movable within the valve body between a first flow position and a second flow position. In the first flow position, the shuttle member defines a first fluid flow path between the first intake passage and the first supply passage and a second fluid flow path between the second supply passage and the reservoir return passage. In the second flow position, the shuttle member defines a third fluid flow path between the second intake passage and the second supply passage and a fourth fluid flow path between the first supply passage and the reservoir return passage. The valve is useful in a bi-directional hydraulic power system having at least one hydraulic component, a reservoir for hydraulic fluid, and a bi-directional pump.

Abstract: In a hydraulic power steering apparatus, hydraulic pressure for generating steering assist power is varied by varying opening of a variable throttle portion by movement of a spool. The spool is disposed in a provisional origin by driving a stepping motor in one direction according to a number of steps for setting provisional origin from a position at a time of start of control, and the number of steps at a time of completing of the driving is set to a provisional origin for calculation. In a return to origin permission state where the spool is disposed in a provisional origin and the number of steps from the provisional origin for calculation is zero, a number of steps at a time when the driving of the stepping motor according to a number of steps obtained by subtracting the number of steps for setting provisional origin from a number of steps for setting origin is completed is set to an origin for calculation, and the movement of the spool is stopped at the origin with a stopper.

Abstract: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

Abstract: A fluid controller includes a first fluid meter defining a first plurality of volume chambers and a second fluid meter defining a second plurality of volume chambers. A selector assembly, disposed between the first fluid meter and the second fluid meter, includes a selector plate defining a bore and a selector valve disposed in the bore. The selector valve is adapted for rotational movement between a first position and a second position and includes a first face and an oppositely disposed second face. The selector valve defines a plurality of thru-passages that extend axially through the first and second faces and that is adapted to provide fluid communication between the first and second volume chambers in the first position. The selector valve defines a groove disposed on the second face. The groove recirculates fluid from the second plurality of volume chambers when the selector valve is in the second position.

Abstract: A method and system for improving steering performance of a vehicle is disclosed. The method and system resides in increasing the flow size of the hydraulic oil flow path from a pump (3) to a steering unit (5). This can be done by modifying the size of a conduit (4) between the pump (3) and unit (5) or by modifying the bore diameter of hose fittings (36, 37).

Abstract: The invention provides a steering system comprising a controlled element which is movable in a neutral area comprising a neutral position and in areas on opposite sides of the neutral area based on a steering input and a handle for requesting a desired position for the controlled element. The handle is movable between set-points in a centre zone comprising a centre set-point and set-points on opposite sides of the centre zone. Furthermore, a steering unit is arranged to receive set-points from the handle, to determine a corresponding controlled position of the controlled element, and to move the controlled element to said controlled position. In order to prevent or reduce jerks, the steering unit is adapted to vary a speed by which the controlled element is moved to the controlled position. The speed is variable in dependence of the received set-point.

Abstract: A piston is disclosed that includes a longitudinal passage disposed between outlets on the opposing faces of the piston, and a radial passage extending from a node with the longitudinal passage to an outlet on the annular wall between opposing piston seals. Check valves are disposed in the longitudinal passage between the node and each of the piston faces, such that each of the check valves enables fluid flow from its inlet to the outlet on the annular wall, and block fluid flow from the outlet on the annular wall to the inlet. In the event of pistons in a fluid system becoming out of phase with each other, fluid may be admitted through the inlet of the longitudinal passage and the respective check valve and out a side wall outlet, thereby bypassing the piston to exit via the respective end port, until another, out-of-phase piston or pistons in the system also reach full extension or retraction, automatically returning all pistons in the system to be in phase with each other.

Abstract: The present invention provides a damping system for use with a mechanism such as a steering system wherein one element moves relative to another element. The system includes a variable volume chamber, a collection chamber, and an inertia track providing fluid communication between the two chambers. A fluid is disposed in the chambers and the inertia track. A compliant tuning member is in fluid communication with the variable volume chamber. The damping system is capable of attenuating vibration at chosen frequencies without adding undesired damping at other frequencies. In the preferred embodiment, the damping system is used to attenuate steering wheel torsional vibration without increasing low frequency damping that would deteriorate steering feel.