Abstract: A steering system for a work vehicle having a steerable wheel. The steering system includes a steering input device configured to provide a first steering input and a second steering input to move the steerable wheel. A pilot system is operatively connected to the steering input device and includes a first pilot line operatively connected to the first steering input and a second pilot line operatively connected to the second steering input. A piloted system is operatively connected to the pilot system and includes a direction control valve operatively connected to each of the first and second pilot lines and to a steering cylinder. The steering cylinder is coupled to the steerable wheel. The direction control valve responds to each of the pressure signals of the first and second pilot lines to adjust the position of the steering cylinder which in turn moves the steerable wheel.

Abstract: Disclosed is a hydraulic control valve assembly of automatic steering system for agricultural machine including a proportional directional valve (3). A balancing valve (1) is arranged between the proportional directional valve (3) and the steering cylinder. A first shuttle valve (2) is arranged between the proportional directional valve (3) and the balancing valve (1). The first shuttle valve (2) is positioned on one side of the proportional directional valve (3). An overflow valve (4) is positioned on another side of the proportional directional valve (3). The overflow valve (4) is connected to a second shuttle valve (6) and a logic valve (5) respectively. The hydraulic control valve assembly has a large control power, a rapid response, and is more suitable for the autonomous navigation operation of agricultural machine. Moreover, the system saves more energy, such that the autonomous navigation operation of agricultural machine is more stable.

Abstract: A steering device for an aircraft landing gear leg including a main fitting has a steering collar for rotatably mounting on the outside of the main fitting; an actuator having an actuator body; and an actuator arm arranged to move between an extended position and retracted position with respect to the actuator body. The actuator arm is pivoted to the main fitting, and a bracket is pivoted to the main fitting; a second pivot location pivoted to the actuator body; and a third pivot location pivotally connected to one end of a steering arm. The steering arm is pivoted at its other end to the steering collar. Also, an aircraft landing gear with the steering device and aircraft having the landing gear.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. A first pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle, during operation of the engine, to supply fluid under pressure to the power steering motor assembly. A second pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle, during operation of the engine. A valve connected with the power steering motor assembly and the second pump directs fluid flow from the second pump to at least one of the power steering motor assembly and reservoir during operation of both the first pump and the second pump. A pumping mechanism includes a first pumping area defining the first pump and a second pumping area defining the second pump. The first pumping area is smaller than the second pumping area.

Abstract: An electric power steering apparatus and control device integrated-type electric motor includes an electric motor driving circuit constituted by a plurality of semiconductor power elements and controlling electric power supplied to an armature winding of an electric motor, a switch device for opening and closing a connection between an input terminal of the electric motor driving circuit and an external power source, and another switch device for opening and closing the armature winding, wherein at least one of both the switch devices is constituted by a semiconductor switch element, and the power elements and the semiconductor switch element are mounted on a board attached to a metallic case.

Abstract: A force feedback system including a first hydraulic cylinder operably coupled to one or more tires of a vehicle, a power assist steering unit operably coupled to the one or more tires of the vehicle, and a second hydraulic cylinder operably coupled to the power assist steering unit, wherein the first and second hydraulic cylinders are hydraulically coupled to transmit force between the first and second hydraulic cylinders.

Abstract: An apparatus for use in turning steerable vehicle wheels includes a power steering motor assembly connected with the steerable vehicle wheels. A first pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly. A second pump connected with the power steering motor assembly is continuously driven by an engine of the vehicle. A valve connected with the power steering motor assembly and the second pump directs fluid flow from the second pump to at least one of the power steering motor assembly and reservoir during operation of both the first pump and the second pump. A pumping mechanism includes a first pumping area defining the first pump and a second pumping area defining the second pump. The first pumping area is smaller than the second pumping area.

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: 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: There is disclosed herein a vehicle configuration comprising a chassis, at least one front wheel, two rear wheels, and a propulsion unit driving the rear wheels. The rear wheels are connected to the chassis by a wheel support assembly configured for allowing movement of each rear wheel relative to the chassis, a hydraulic cylinder connected to the chassis and the rear wheel supports, and a piston connected the rear wheel supports and the chassis. The piston dividing the hydraulic cylinder into fluidly connected first and second chambers such that movement of hydraulic fluid from the first or second chamber of a hydraulic cylinder to the respective first or second chamber of another hydraulic cylinder displaces the pistons of the hydraulic cylinders in opposing directions relative to the respective housings and causes the chassis to articulate with respect to the surface.

Abstract: A power steering apparatus including a power cylinder, first and second pumps, a control valve serving for selectively supplying a working fluid supplied from the first or second pump to one of a pair of pressure chambers of the power cylinder in accordance with a steering operation, first and second reservoir tanks, and a return passage changeover valve disposed between the control valve and the first and second pumps, the return passage changeover valve serving for communicating the first and second pumps with the control valve regardless of an axial position of a valve element and communicating one of the first and second reservoir tanks with the control valve in accordance with the axial position of the valve element to thereby carry out changeover between circulating fluid passages for circulating the working fluid to the first reservoir tank and the second reservoir tank.

Abstract: A power steering gear assembly 10 which is used to turn steerable vehicle wheels 50, 52 includes a piston 20 disposed in a motor cylinder 16. A series 44 of rack teeth are connected with the piston 20. A first tooth space 94 is formed between first and second teeth 80, 76 in the series 44 of rack teeth. The first tooth space 94 has a root portion 126 which includes first and second fillets 132, 136. The first fillet 132 has a larger radius of curvature 130 than the second fillet 136. The first and second fillets 132, 136 have centers of curvature which are both disposed between a central axis 104 of the first tooth space 94 and the second rack tooth 76. The center pinion gear tooth 190 has side surfaces 200 and 202 with intermediate portions 216 and 230 which are offset from continuously curving spatial envelopes 212 and 228 containing tip end portions 208 and 222 and root end portions 210 and 224 of the center pinion gear tooth.

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: An apparatus (1) is used to turn steerable vehicle wheels (50, 52). The apparatus includes a valve (92, 120) which is operated in response to an output from a steering angle sensor (80). When a piston (2) in a power steering motor (12) has reached an end of stroke position, an output from the steering angle sensor (80) operates the valve (92, 120) to interrupt operation of the power steering motor.

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: 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 hydraulic power steering apparatus for a vehicle is disclosed. The hydraulic power steering apparatus for a vehicle forms a working fluid film between a piston reciprocating within a cylinder tube and a piston ring in order to provide an accurate auxiliary steering force by preventing leakage of a working fluid between right and left cylinders during the operation of a steering wheel by the driver.

Abstract: A steering control apparatus is provided with first and a second steering mechanisms serving to assist a steering force exerted by a driver via a steering wheel. The first steering mechanism employs a first electric motor to apply a rotational torque to a pinion shaft, and the second steering mechanism uses a hydraulic oil pressure to apply a thrusting force to a rack bar.

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 steering system for motor vehicles has a steering handle operable by the driver and connected to steerable vehicle wheels in terms of effect to determine a direction of driving. The vehicle steering system includes a hydraulic working cylinder having two directions of effect, as well as a hydraulic pressure source, which applies hydraulic pressure to a valve assembly. The valve assembly controls the magnitude of the hydraulic pressure conveyed to the working cylinder and determines the direction of effect of the working cylinder. The valve assembly has two separated valves, the first valve determining the direction of effect of the working cylinder, while the second valve controls the working pressure for the hydraulic working cylinder.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (12, 14) includes first and second piston and cylinder type hydraulic motors (32, 34) which are connected with a central portion of a vehicle. A steering control valve (24) is operable in response to manual rotation of a steering wheel (18) to effect extension and contraction of the first and second hydraulic motors. A rack and pinion steering gear (110, 114) may be connected with a piston rod (86) of one of the hydraulic motors (32). A secondary control valve (200) may be provided to effect operation of one of the hydraulic motors to a greater extent than the other hydraulic motor.

Abstract: An engine driven pump 24 is connected with a power steering motor assembly 18. An electric motor 36 drives a pump 34 connected with the power steering motor assembly 18. A control apparatus 38, 44, 52, 62 and 72 effects operation of the electric motor 36 to drive the pump 34 when the power steering motor assembly 18 requires fluid in addition to fluid supplied by the engine driven pump 24.

Abstract: A dual counterbalance valve is added in the hydraulic lines between the steering unit and the steering cylinders on an implement to maintain pressure in the steering lines by metering hydraulic fluid to and from the cylinders under pressure so that the steered wheels stay in phase. Since the steering system is kept under constant pressure, the wheels can only be steered by the steering unit and not by tractive soil forces so toe in and toe out problems are eliminated without need for a mechanical tie rod connecting the steered wheels. The valve is added in-line to the system so that current machines can be easily retrofitted.

Abstract: A dual counterbalance valve is added in the hydraulic lines between the steering unit and the steering cylinders on an implement to maintain pressure in the steering lines by metering hydraulic fluid to and from the cylinders under pressure so that the steered wheels stay in phase. Since the steering system is kept under constant pressure, the wheels can only be steered by the steering unit and not by tractive soil forces so toe in and toe out problems are eliminated without need for a mechanical tie rod connecting the steered wheels. The valve is added in-line to the system so that current machines can be easily retrofitted.

Abstract: A power assist steering system is provided for use on a vehicle that has a steering implement and a steering mechanism operatively connected to a first wheel. The power assist steering system includes first and second vacuum actuators or a double acting vacuum actuator, vacuum source for providing a vacuum to the first and second vacuum actuators, a first disc powered relative to second disc for selectively activating the first and second vacuum actuators and a gear and gen plate for assisting the steering mechanism in turning the first wheel in first and second directions.

Abstract: A hydraulic steering apparatus having a small angle of operation, can be minutely and smoothly controlled and requires a small number of operation times. The hydraulic steering apparatus is mounted onto an automatic traveling vehicle and has a pilot valve which is switched from a neutral position to a steering position upon receiving a target steering angle from a target steering angle input means. A main steering valve is switched from a neutral position to a steering position upon receiving pressurized oil from the pilot valve and outputs pressurized oil to multiple hydraulic actuators in order to produce an actual steering angle. An excitation current output means outputs an excitation current corresponding to a deviation angle between the target and actual steering angles to an electromagnetic variable pressure reducing valve.

Abstract: A steering axle with hydrostatic two-circuit steering system for agricultural, forestry and construction vehicles. The steering axle includes a first double-acting pressure medium cylinder (1) which in the area of its center is connected with an axle bridge housing (2) and at its two ends with joint housings (4, 5) via tie bars (3) and an additional second double-acting pressure medium cylinder (6) which is mounted on one side of the axle. The second cylinder acts simultaneously together with the first pressure medium cylinder (1). In this manner a two-circuit steering system is obtained. At the same time said second double-acting pressure medium cylinder (6) is connected at one end via a ball joint (7) with a joint housing (5) and at the other end is fastened on the axle bridge housing (2).

Abstract: A power assist steering system is provided for use on a vehicle that has a steering implement and a steering mechanism operatively connected to a first wheel. The power assist steering system includes first and second vacuum actuators, a vacuum for providing a vacuum to the first and second vacuum actuators, an actuator for selectively activating the first and second vacuum actuators and a power assist for assisting the steering mechanism in turning the first wheel in first and second directions.

Abstract: A power steering system for construction equipment is disclosed. In the steering system, a plurality of internal passages are selectively formed in the directional control valve for left and right steering cylinders. The internal passages thus selectively allow pressurized oil to be fed from an oil pump into both the large chamber of the right cylinder and the small chamber of the left cylinder with a reversible motor starting by pressurized oil discharged from the other chambers of the two cylinders in the event of rotating the steering wheel to the left. The internal passages also allow the pressurized oil to be fed into both the small chamber of the right cylinder and the large chamber of the left cylinder so that the motor is started by pressurized oil discharged from the other chambers of the two cylinders when the steering wheel rotates to the right.

Abstract: A power steering system for on-the-road and off-the-road vehicles includes a positive displacement hydraulic power steering pump, a master power gear with a rotary valve and a slave power gear mounted in tandem with the master power gear. Heated return hydraulic fluid from the master power gear flows through a heat transfer passage in the slave power gear and is cooled.

Abstract: A steering system for an articulated vehicle (11) including steering cylinders (19, 21) wherein the steering system includes a steering control valve (31) having a housing (33) fixed to a rear bogie portion (15). The steering control valve (31) includes a spool valve (49) receiving steering input and a follow up sleeve valve (51) which receives feedback representative of a change in the articulation angle of the front bogie portion (13) by means of a linkage arrangement (123, 117, 63). Either the follow up movement of the sleeve relative to the spool, to reduce main system flow, or the follow up of the sleeve relative to the housing, to reduce the load signal, is used as a way of cushioning the steering, as the front and rear bogie portions (13, 15) approach maximum articulation.

Abstract: An electrohydraulic steering system has a three position pilot operated directional valve disposed between a variable displacement pump and a pair of steer cylinders. The directional valve controls the direction of fluid flow from the pump to the steer cylinders while the displacement of the variable displacement pump is controlled to vary the rate of fluid flow to the steer cylinders. The directional valve is moved to an on position in response to a pilot signal delivered thereto from a pilot valve device while the displacement setting of the variable displacement pump is varied by an electrical signal delivered to a displacement controller from a position sensor mechanism.