Abstract: 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.

Abstract: A milling machine can include a frame; at least two tracks coupled to the frame for propelling the milling machine; first and second hydraulic cylinders configured to steer each of the at least two tracks, respectively; an adjustable hydraulic tie rod extending between the at least two tracks; first and second steering collars coupled to the each of the tracks to move the tracks, wherein the first hydraulic cylinder is coupled to the first steering collar and the second hydraulic cylinder is coupled to the second steering collar, and wherein the adjustable hydraulic tie rod is coupled to both of the steering collars; one or more sensors to determine the positions of the at least two tracks; and a hydraulic steering control system coupled to the first and second hydraulic cylinders and the adjustable hydraulic tie rod and configured to vary a steering mode of the at least two tracks between a parallel steering mode and an Ackerman steering mode, wherein if one of the one or more sensors fails, the hydraulic st

Abstract: An electro-hydraulic hybrid system for a vehicle utilizes both the advantages of the hydraulic hybrid system and the electric hybrid system to maximize the collection of energy lost during a braking process and to provide launch assists in an acceleration process. The electro-hydraulic hybrid system includes an ECU that controls the electro-hydraulic hybrid system, a hydraulic drive pump, an accumulator, a hydraulic reservoir, a hydraulic pump, an electric motor, a power converter, and a battery. The hydraulic reservoir is in fluid communication with the accumulator through the hydraulic drive pump that functions as the main component of the hydraulic regenerative braking system. The hydraulic reservoir is also in fluid communication with the accumulator through the hydraulic pump that acts as the main component of the electro-hydraulic inter-conversion unit along with the electric motor, the at least one battery, and power converter that are electrically connected to each other.

Abstract: A hydraulic circuit for a motor vehicle supports operation of a power steering gear and a power assisted park brake unit incorporating a spring actuated hydraulic release (SAHR) chamber. The hydraulic circuit includes a pump with the power steering gear being connected to receive hydraulic fluid under pressure from the pump. Hydraulic fluid from the pump is delivered to first and second valves, the first or release control valve being connected to the SAHR chamber and the second or recirculation valve being coupled to return hydraulic fluid to a pump inlet.

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: Method for cleaning hydraulic liquid in a industrial truck, wherein said industrial truck is an electrically powered industrial truck having a battery as an energy source with a hydraulic system comprising, a hydraulic pump, a hydraulic reservoir, and a return pipe to the hydraulic reservoir with a return filter, wherein the method comprises the steps of, the hydraulic pump is activated for hydraulic activity, the hydraulic pump pumps the liquid for the hydraulic activity and in relation to this return flow through the return filter to the hydraulic reservoir occurs, the hydraulic pump can be activated by means comprised in the industrial truck, when hydraulic activity is not present, by that achieving a circulation to the hydraulic reservoir through the return filter such that sufficient filtration of the hydraulic liquid is reached, further a time Tb for circulation without hydraulic activity can be accumulated and/or a sensor for determining the quality of the hydraulic oil can be arranged in the industria

Abstract: An auxiliary element is incorporated into a steering apparatus and that, in addition to the steering circuit, a further steering circuit is provided on the same axle. A movement is forced upon the auxiliary element by a further kinematic coupling, such that the movement is additionally transmitted to the opposite wheel by the auxiliary element. The transmission increases boost to the steering force.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (14, 16) includes a first pump (30) driven by an engine (42) of the vehicle to supply fluid to the fluid inlet (38) of a power steering motor assembly (12). A second pump (46) is driven by the engine (42) to supply fluid under pressure to the power steering motor assembly (12). The second pump (46) has an input (48) connected in fluid communication with an output (36) of the first pump (30) when a pressure at the fluid inlet (38) is below a predetermined value.

Abstract: Cut-in-cut-out valves for hydraulic circuits. The hydraulic circuits include a hydraulic pump outputting a variable pressure controlled by a slaving line, an accumulation circuit, a return line to the reservoir, a cut in-cut-out valve. The hydraulic circuits also include a cut-in-cut-out valve having four orifices, a first orifice connected to the supply line, a second orifice connected to the slaving line, a third orifice connected to the return line leading to the reservoir, and a fourth orifice connected to the accumulation circuit. The cut-in-cut-out valve alternates between two positions as a function of the pressure in the accumulation circuit, a cut-in position in which the first, second and fourth orifices are connected to each other, and a cut-out position in which the first and fourth orifices are closed.

Abstract: A vehicle having a power supply apparatus which is configured to supply an electric power to an external apparatus outside the vehicle, includes: a detecting unit which is configured to detect a state where a cable is pinched between an opening and closing member of the vehicle and an opening edge of an opening for the opening and closing member, the cable connecting the power supply apparatus to the external apparatus and being arranged in an interior of the vehicle; and an inhibiting unit which, when the detecting unit detects that the cable is pinched between the opening and closing member and the opening edge, is configured to inhibit running of the vehicle.

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 hydraulic steering assist assembly is provided for a vehicle with a mechanical steering assembly operable by a user to steer the vehicle. The hydraulic steering assist assembly includes a hydraulic actuator adapted to be coupled to the mechanical steering assembly and has a first side and a second side. A bi-directional hydraulic pump is placed in fluid communication with the first side and the second side of the hydraulic actuator. The hydraulic steering assist assembly further includes a valve in fluid communication with the first side and the second side of the hydraulic actuator, and a control system for controlling the bi-directional hydraulic pump and the valve. The bi-directional hydraulic pump provides a pressurized fluid to the hydraulic actuator, which applies a force on the mechanical steering assembly to assist steering the vehicle. The valve can act as a steering damper.

Abstract: A method for selectively charging and discharging a steering accumulator are provided. One vehicle steering system includes a hydraulic pump configured provide a source of pressurized hydraulic fluid for use in steering the vehicle. The steering system also includes an accumulator configured to hold pressurized hydraulic fluid from the pump for use in steering the vehicle in case of need. The steering system includes a charging circuit configured to selectively allow the hydraulic fluid to flow from the hydraulic pump to the accumulator based on a fluid pressure applied by a first pilot and a second pilot. The steering system includes a charging bypass circuit configured to allow the hydraulic fluid to flow to a steering control unit and to bypass the charging circuit. The hydraulic pump supplies fluid to the charging circuit and the bypass circuit.

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: A method for securing the assistance torque (15) supplied by an electric assistance motor (8) in a motor vehicle power steering system includes the steps of: estimating the force on the steering system rack from the torque exerted by the driver on the steering wheel (2), from the assistance torque (15), and optionally from other parameters such as the speed of the electric assistance motor; comparing a target assistance torque with an authorized assistance range, defined with respect to the estimated rack force (17) at any moment, and in the event the target assistance torque is maintained above predefined limits for a predefined duration, correcting and optionally interrupting the power steering.

Abstract: A system and method for selectively charging and discharging a steering accumulator are provided. One vehicle steering system includes a hydraulic pump configured provide a source of pressurized hydraulic fluid for use in steering the vehicle. The steering system also includes an accumulator configured to hold pressurized hydraulic fluid from the pump for use in steering the vehicle in case of need. The steering system includes a charging circuit configured to selectively allow the hydraulic fluid to flow from the hydraulic pump to the accumulator based on a fluid pressure applied by a first pilot and a second pilot. The steering system includes a charging bypass circuit configured to allow the hydraulic fluid to flow to a steering control unit and to bypass the charging circuit. The hydraulic pump supplies fluid to the charging circuit and the bypass circuit.

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: An apparatus for use in turning steerable vehicle wheels includes a first pump driven by an engine of the vehicle to supply fluid under pressure to a power steering motor assembly through a supply conduit. A second pump driven by the engine of the vehicle supplies fluid under pressure to the power steering motor assembly when the flow of fluid in the supply conduit is below a predetermined value. The second pump is inactive when the flow of fluid in the supply conduit is above the predetermined value. The second pump has vanes located in slits. A valve which is in fluid communication with the slits has a first condition in which fluid under pressure is supplied to the slits. The valve has a second condition in which the slits are in fluid communication with a reservoir.

Abstract: A hydraulic power steering unit has an assist force generating unit that uses oil to generate assist force for steering by a steering device, a variable flow oil pump unit that supplies oil to the assist force generating unit, and a controller that controls the oil pump unit. The controller has a command flow setting device that sets a command flow rate Qc of the oil supplied from the oil pump unit to the assist force generating unit in accordance with a vehicle quantity of state such as a vehicle speed, steering angle or the like. The controller also has a flow correcting device that corrects the command flow rate Qc in accordance with the speed of the oil pump unit.

Abstract: In a vehicle including a traction engine designed to drive wheels through a driveline that includes an upstream portion which is connected to the engine and a downstream portion which is permanently connected to the drive wheels, the power steering system includes a hydraulic circuit including a fluid tank and a steering actuator. The power steering system further includes a first pump which is driven by mechanical power from the downstream portion of the driveline, and a second pump which is driven by an electric motor. The first and second pumps are arranged in parallel between the fluid tank and the steering actuator and are capable of supplying fluid from the fluid tank to the steering actuator at the same time.

Abstract: A power steering system for a ground vehicle includes an accumulator that supplies high-pressure fluid through a control valve to a fluid motor that drives the steerable wheels of the vehicle. A normally open control valve between the accumulator and the fluid motor closes prior to the steerable wheels reaching an axle stop to relieve power assist.

Abstract: A force steer axle assembly is disclosed for providing redundant fail-safe steering control to an axle. The assembly includes a centering cylinder for maintaining the axle in a centered position and for steering the axle as directed. The assembly further includes a hydraulic control system for providing centering and steering actuation to the cylinder, and an electrical control system for receiving user input and controlling the hydraulic system.

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: 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: 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 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: A hydraulic steering assistance system for vehicles, including a power steering pump and a variable-ratio gear, particularly a booster drive for the power-steering pump wherein the power steering pump hydraulically powers both the hydraulic steering assistance system and the variable-ratio gear.

Abstract: A water drain valve for an electromechanical motor vehicle power steering may include a base and a diaphragm which is configured as a movable valve element and is arranged such that it can move relative to the base between a closed position and an open position. In the closed position, the diaphragm rests against the base along an annular ring. The base may have a passage which extends from a free opening to a floor, with the diaphragm being attached centrally to the floor, the floor having at least one opening which forms a connection from the passage to the diaphragm, and the floor having at least one groove which is open towards the diaphragm and extends from the at least one opening as far as the annular ring.

Abstract: A reservoir-less power steering system having a hydraulic pump, a storage tube, a steering gear assembly, and a return line. The storage tube accommodates and provides hydraulic fluid to the hydraulic pump. Further, the hydraulic pump increases the hydraulic fluid pressure and transfers the pressurized hydraulic fluid to the steering gear assembly. A return line is connected to the steering gear assembly and coupled to the storage tube for returning the hydraulic fluid from the steering gear assembly to the hydraulic pump. Moreover, the storage tube extends upwards from the hydraulic pump to include a hydraulic fluid level measurement assembly.

Abstract: A hydraulic system for a mobile working machine includes a hydraulic pump, a steering valve, a steering actuator controlled by the steering valve, a first hydraulic line which extends between the hydraulic pump and the steering valve, and a hydraulic storage unit which is connected with the first hydraulic line via a second hydraulic line). So as to optimize a pressure state for the hydraulic system, a throttle connected in parallel with a check valve is located in the second hydraulic line. The check valve permits one-way fluid flow in a direction away from the hydraulic storage unit.

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: An articulated construction vehicle is provided with an articulated, self-propelled body, body-articulating hydraulic cylinders for articulating the self-propelled body, a pilot-operated directional control valve for controlling a flow of pressure oil to the body-articulating hydraulic cylinders, and a steering-wheel-operated control device for outputting a pilot signal to corresponding one of signal-receiving ports of a directional control valve by rotational operation of a steering wheel.

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: 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 hydraulic auxiliary power steering for motor vehicles having a source for a hydraulic medium, in particular an oil pump, which can be driven during operation by a drive device, in particular by an internal combustion engine of the vehicle or by an electric motor, having a steering transmission and having a line system for the hydraulic medium connecting the source to the steering transmission, wherein the line system has at least two line sections through which the hydraulic medium can flow.

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 steering system includes a steering unit which can be configured to convert an operation input to an input shaft into an arbitrary amount of rotation or an arbitrary turning force and output the arbitrary amount of rotation or the arbitrary turning force from an output shaft. A steering handlebar can be configured to be coupled to the input shaft. A support bracket can be configured to be coupled to the output shaft and to support a front wheel of the vehicle. A housing can be configured to accommodate the steering unit. The steering unit can be configured to be mounted to a front end portion of a vehicle body frame of the vehicle integrally therewith by the housing.

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 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 power-steering hydraulic actuating circuit for a motor vehicle, including a hydraulic fluid distributing valve including hydraulic fluid supply ports connected to a pump via lines. A mechanism restricts the cross section of hydraulic fluid flow from the pump to the port and is provided on the high-pressure line.

Abstract: In a power steering device, a hydraulic power cylinder is configured to assist a steering force of a steering mechanism linked to steerable road wheels, a pump is configured to supply a hydraulic pressure to respective pressure chambers of the hydraulic power cylinder, an electric motor is configured to drive the pump, a torque sensor is configured to detect a steering torque of the steering mechanism, an operating load state detecting circuit is configured to detect an operating load state of the pump based on a viscosity resistance characteristic of a working oil, and an electric motor control circuit is configured to output a drive signal to the motor on the basis of a torque signal from the torque sensor and the operating load state of the pump.

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: [Problem] 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. [Solution] 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: The invention concerns a hydraulic steering arrangement (1) with a supply connection arrangement (P, T), a working connection arrangement (A, B) connectable to a steering motor (5), a steering unit (6) located between the supply connection arrangement (P, T) and the working connection arrangement (A, B), and a steering valve (14) whose outlet is connected to the working connection arrangement (A, B). It is endeavoured to keep the load of such a steering arrangement small. For this purpose, the steering unit (6) is made as an open-center steering unit, an inlet (20) of the steering valve (14) being connected to a pressure supply arrangement (22) that can be activated by an activation of the steering valve (14).

Abstract: A power steering gear for a heavy vehicle includes a housing and a flow path for a power steering fluid. A heat exchanger is mounted to the housing or is a part thereof. The heat exchanger includes a first flow path for the power steering fluid and a second flow path for a coolant adapted to exchange heat with the power steering fluid. A cooling system for a power steering gear, a heavy vehicle comprising a power steering gear having such a cooling system, and a method of cooling the power steering fluid of a power steering gear on a heavy vehicle are also disclosed.

Abstract: [Problem] To provide an articulated vehicle which permits steering control not only suited for traveling on general roadways but also suited for work at construction sites. [Solution] An articulated construction vehicle is provided with an articulated, self-propelled body 1, body-articulating hydraulic cylinders 2 for articulating the self-propelled body, a pilot-operated directional control valve 5 for controlling a flow of pressure oil to the body-articulating hydraulic cylinders 2, and a steering-wheel-operated control device 6 for outputting a pilot signal to corresponding one of signal-receiving ports of a directional control valve 7 by rotational operation of a steering wheel 7A.

Abstract: A travel jolt minimizing assembly for use in association with an articulated loader steering environment having a orbitrol pump, and a flow amplifier coupled to the orbitrol pump through a left orbitrol signal and a right orbitrol signal, and a steering cylinder coupled to the flow amplifier. The travel jolt minimizing assembly includes a system for temporarily diverting the left orbitrol signal within a predetermined degrees of a full articulation in a left direction and a system for temporarily diverting the right orbitrol signal within a predetermined degrees of a full articulation in a right direction. The invention further includes a response cushion assembly which minimizes jolts which occur upon a rapid change in direction.

Abstract: In a power steering system, the steering state of wheels is detected based on the steering speed to judge as to whether the steering state is in turning of the steering wheel or holding of steering speed is the steering wheels. At the time of the steering operation state, the control is executed so that a difference between a torque command value to an electric motor and the actual torque thereof will become smaller. Also, at the time of the holding operation state, the control is executed so that a difference between the revolution speed of the electric motor and a revolution-speed command value thereto will become smaller.

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.