Abstract: An agricultural implement has front flotation wheels with a significantly increased diameter, increasing flotation and improving rolling characteristics, especially in soft soil conditions. The implement has a frame supported on front and rear wheels. Front flotation wheels are pivotally mounted to the frame about vertical axes. A hitch tongue is pivotally attached to the frame about a vertical hitch pivot axis. A wheel control mechanism connects the front flotation wheels to the hitch tongue, and is configured such that when the hitch tongue is in a neutral position the front flotation wheels roll in the operating direction, and pivoting the hitch tongue causes the front flotation wheels to pivot in the same direction.

Abstract: A ratchet assembly may include a steer ring, a steer ring side structure, a steer cylinder bracket arm, a steer cylinder, a ratchet lock gear, a steering collar, a ratchet cylinder, a ratchet lock bar, and at least one sensor. When in a particular locked position, operation of the steer cylinder rotates the steer ring, the ratchet lock gear, and the steering collar. When in an unlocked position, operation of the steer cylinder rotates the steer ring around the ratchet lock gear.

Abstract: The present invention relates, in general, to a steering device for tractor and, more particularly, to a steering device for a tractor for enabling front wheels of the tractor to be turned to an angle over or approximate to a right angle with respect to the longitudinal direction of the tractor by means of a driver manipulating a steering handle, thus making it possible to increase the steering angle of the front wheels and making the turning of the front wheels smoother, whereby the tractor can turn around in place and easily perform different kinds of tasks, for example, a task required in a limited space, a task where there is a need for turning the tractor around in place, etc.

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: The present invention relates to a steering apparatus for turning front wheels of a tractor. More particularly, the present invention provides a steering apparatus for tractors which includes a steering cylinder provided with left and right cylinder rods which are extended and retracted to the left and the right by steering force transmitted by hydraulic pressure when the driver manipulates the steering wheel, wherein swing links are respectively hinged to ends of the left and right cylinder rods, thus forming a first four-bar link structure, and second four-bar link structures are respectively formed on left and right ends of the first four-bar link structure so that the front wheels can be turned, whereby an angle range within which the front wheels can be turned can be increased.

Abstract: The invention relates to a steering system for a utility vehicle, wherein the steering movement is transmitted to the utility vehicle wheels via a steering linkage provided on a steering unit (16, 17; 77). The steering unit (16, 17; 77) is arranged so as to be displaceable along a guide unit (15) which is fixed relative to the utility vehicle. A displacing force upon the steering unit (16, 17; 77) may be provided by a hydraulic cylinder arrangement integrated into the steering unit and/or by a mechanical coupling to a steering wheel for example.

Abstract: A pump apparatus includes: a first housing member which includes a first drive shaft insertion hole; a second housing member which includes a second drive shaft insertion hole; a pump drive shaft; a first abutment portion and a second abutment portion formed in the second housing member; the first and second drive shaft insertion holes being previously co-processed in a state in which the first and second housing member are relatively positioned by abutments between the first and second positioning protruding portions and the first and second abutment portions, and a joining member joining the first and second housing members in a state in which the first and second housing members are relatively positioned by the abutments of the first and second positioning protruding portions and the first and second abutment portions so as to re-create a relative position between the first and second housing members at the co-processing.

Abstract: A vehicle steering system includes a gear rack supported in a fixed position, a pinion gear in meshing engagement with the gear rack, a steering subsystem supporting the pinion gear and moveable in a translational manner relative to the gear rack and at least one steering arm coupled to steering subsystem and configured to steer a motive member in response to movement of the steering subsystem. The vehicle steering system is configured to remain substantially within a framework of the vehicle while steering one or more motive members of the vehicle.

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: 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: A fluid system is described, which comprises first and second cylinders, each of which comprises a piston, and a first end and a second end corresponding to full stroke positions of the corresponding piston. The first ends and second ends of the two cylinders thereby define four cylinder ends. The first and second cylinders are fluidly coupled to each other via a first matched pair of cylinder ends selected from the first ends or the second ends. The system includes first and second bypass devices. The bypass devices are each configured so that when a full stroke position is occupied at a respective bypass end from among the four cylinder ends by the corresponding piston, the respective bypass device opens an outlet that allows a flow from the respective cylinder to bypass to a conduit coupled to the respective bypass end. This allows for the two cylinders to self-correct any tendency to lose synchronization with each other, and allows the system to balance pressure between the two cylinders.

Abstract: A power steering apparatus includes an input shaft, an output shaft, a piston arranged to separate a first hydraulic chamber and a second hydraulic chamber, a ball screw mechanism, an output member, a control valve configured to supply hydraulic fluid selectively to the first hydraulic chamber through a first connecting passage and to the second hydraulic chamber through a second connecting passage, a first damper valve provided in the first connecting passage, a second damper valve provided in the second connecting passage, and a housing enclosing the piston. The housing is formed with a first valve receiving hole in which the first damper valve is disposed, and a second valve receiving hole in which the second damper valve is disposed.

Abstract: The invention relates to a steer-by-wire steering system comprising a hydraulic control unit that acts on the steerable wheels (1, 20), the control unit having at least one cradle (4, 23), which is displaceably mounted on at least one guide rod (5, 24) that passes through the respective cradle (4, 23). The respective cradle (4, 23) and the corresponding guide rod(s) (5, 24) form working chambers (A11, A12, A21, A22) of a piston-cylinder system, whereby each respective guide rod (5, 24) has at least one channel (KA11, KA12, KA21, KA22), each terminating in the vicinity of a working chamber (A11, A12, A21, A22). The cradle or cradles (4, 23) adjust the steerable wheels (1, 20) directly or by means of steering tie rods (2, 21).

Abstract: The hydraulic steering mechanism according to the present invention includes an axle case, a first steering case, a second steering case, a first arm, a second arms, a third arm, a hydraulic actuator, and a tie rod. The first, second and third arms are provided to the first steering case, the second steering case and the axle case, respectively. The hydraulic actuator includes a cylinder and a piston for moving with respect to each other by an action of hydraulic pressure. The first and second arms have tie rod mounting portions to which the tie rod is mounted. At least one of the first and second arms has a first hydraulic actuator mounting portion to which one of the cylinder and the piston in the hydraulic actuator is mounted. The third arm has a second hydraulic actuator mounting portion to which the other of the cylinder and the piston in the hydraulic actuator is mounted.

Abstract: A steering system for a small-sized vehicle is capable of coaxially arranging a steering shaft and a power steering apparatus with high accuracy. In the steering system, when the power steering apparatus is connected to the steering shaft, a plurality of bearings support the steering shaft on a vehicle body frame, and where the axis of the steering shaft arranged at a desired position is a reference axis, at least one of the bearings is configured to compensate for an inclination of the steering shaft or further, to compensate for a deviation from the bearing which is centered with respect to the reference axis.

Abstract: A power steering system includes a reversible-type oil pump supplying hydraulic fluid to first and second pressure chambers of a hydraulic power cylinder through first and second passages and having first and second discharge ports, and a branch passage conveying part of hydraulic fluid discharged from the discharge ports of the oil pump to the outside of the pressure chambers of the power cylinder, wherein the branch passage has a passage sectional area greater than a total leak sectional area of the oil pump.

Abstract: An electric power steering apparatus transmits a driving force of an electric motor to a steering mechanism for steering assist. The apparatus includes a torque sensor which detects a steering wheel torque; a basic assist characteristic determining section which determines a basic assist characteristic defining a basic characteristic of a motor driving target value for the steering torque; a motor driving target value determining section which determines the motor driving target value for the steering torque in accordance with a modified assist characteristic prepared by shifting the basic assist characteristic along a steering torque coordinate axis; a shift amount determining section which determines the amount of the shift from the basic assist characteristic to the modified assist characteristic on the basis of the steering torque; and a motor driving section which drives the electric motor on the basis of the motor driving target value.

Abstract: The degrees of freedom in the design of a layout structure of a power steering system for a vehicle are increased so that the auxiliary parts can be arranged around the power assisting actuator without the need for a special increase in the strength and in the stiffness of a body frame for installing the power steering system. The front wheels are steered by a power steering system supported by the body frame wherein the power steering system is provided with an actuator for assisting a steering force. One end of the actuator is installed to a first cross pipe laid over the left and right portions of the body frame. The arrangement is such so that a longitudinal direction of the actuator runs substantially in parallel with a center line of a chassis extending in a back-and-forth direction of the vehicle body.

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.

Abstract: A hydraulic power-assisted steering system, in particular for motor vehicles, has a hydraulic pump for generating hydraulic pressure for assisting the steering and an electromagnetic valve, in addition to a motor for driving the hydraulic pump. The hydraulic pump can be decoupled from the motor by a coupling.

Abstract: An integrated hydraulic control system includes a steering control unit and a priority flow divider integrated into a unitary casing. An interface fluidly couples the casing for the steering control unit and priority flow divider directly to a control valve casing. All hydraulic communication between the steering control unit, the priority flow divider, and the control valve are located inside the casings.

Abstract: An integral power steering apparatus includes a stroke limiter. A piston defines two hydraulic chambers in a housing. A communicating passage, a first valve disposed between the first hydraulic chamber and the communicating passage, and a second valve disposed between the second hydraulic chamber and the communicating passage, are provided to serve for a stroke limiter, in addition to a hydraulic circuit for supplying hydraulic fluid to the two hydraulic chambers. The two valves each include a valve body having a bore and serving as a valve seat, a plunger slidably fitted within the bore of the valve body and serving as a valving element, and a spring disposed on the bottom of the bore of the valve body and biasing the plunger to be in contact with the valve body.

Abstract: Method and arrangement for operating self-steering wheels on a non-driving axle (3) in a vehicle, which wheels (1, 2) are each mounted on their own stub axle (4, 5) and connected to a tie rod (8). The axle (3) and one (4) of the stub axles are connected by a cylinder (12) with two separate chambers (16, 17), each chamber having an individually adjustable piston (22, 23), the cylinder (12) having a first, freely movable state, in which its length is variable, and a second, pressurized state, in which its length (S3) is fixed, and in that each chamber (16, 17) has at least one connection (18, 19, 20, 21) for pressure medium for acting on the respective piston (22, 23) in the cylinder (12).

Abstract: In a control unit for use with a power steering apparatus, there are provided and integrated into a single body, a main operating fluid feed device for supplying the hydraulic cylinder with an amount of oil corresponding to the amount of rotation of the steering wheel H, an auxiliary operating fluid feed device for supplying a correcting oil for adjusting drive of said hydraulic cylinder according to control signal, and a steering wheel angle sensor disposed around the rotating shaft of the steering wheel connected to said main operating fluid feed device, to detect steering wheel angle corresponding to the rotating position of said steering wheel.

Abstract: A power steering system for automotive vehicles has a construction for reducing noise generated due to pressure change of hydraulic fluid in the power steering system. In the power steering system, an orifice tube is disposed in a joint portion between the first return tube and the second return tube. The orifice tube includes an orifice tube body and a flange, the orifice tube body has an outer diameter equal to an inner diameter of the first return tube so that the orifice tube body can be inserted in the first return tube. The flange has an outer diameter equal to an inner diameter of the second return tube so that the flange can be inserted in the second return tube.

Abstract: An apparatus (10) for use in turning steerable vehicle wheels (12) includes a steering wheel (18) and a power steering motor (20) which is operated in response to rotation of the steering wheel. A first spring (120) is connected with the steering wheel (18) and urges the steering wheel to rotate in one direction. A second spring (124) is connected with the power steering motor (20) and urges the power steering motor to operate in a direction to urge the steering wheel (18) to turn in a direction opposite to the direction in which the first spring (120) urges the steering wheel to turn. The two springs (120, 124) cooperate to take up lash in a linkage (24) between the power steering motor (20) and the steering wheel (18).

Abstract: A steering cylinder retention system is provided that replaces the conventional bolted joint with a pin and snap ring arrangement that requires fewer parts and is easier to assemble. The retention system provides a pair of annular axle brackets whereby the steer cylinder is received in both axle brackets. The steer cylinder is retained in the axle brackets by a shoulder, pin and snap ring assembly. More specifically, the steer cylinder is formed with a seating shoulder that abuts one of the axle brackets, and a slot is provided between the cylinder and axle bracket to prevent rotational movement of the cylinder with respect to the axle bracket. A snap ring arrangement fastens the cylinder against axial movement with respect to the axle cylinder.

Abstract: A rack and pinion steering system for a sport utility vehicle having a solid front axle includes a pinion gear connected to the steering column of the vehicle and a rack gear meshed with the pinion gear. A coupling segment is moved by the engagement segment, and an arm is connected to the coupling segment. A drag link in turn is connected to the arm and is coupled to a first front wheel of the vehicle. Also, a tie rod couples the first front wheel to the second front wheel of the vehicle. With this structure, rotation of the pinion gear by the steering column causes the rack gear and arm to move translationally, thereby moving the drag link to turn the first front wheel. The first front wheel cooperates with the tie rod to simultaneously turn the second front wheel.

Abstract: A vehicle steering gear for transferring rotational movement of a pinion (6) associated with a vehicle steering mechanism into axial movement of a tie rod connected with steerable wheels in the vehicle. The steering gear comprises a piston (1), first and second piston rods (2), a cylinder (3) encircling the piston and partially defining first and second chambers which are separated by the piston. A piston ring (17) seals the piston (1) inside the cylinder (3). First and second bushings (4) seal the ends of the cylinder (3) around the piston rods (2). A rack member comprising an arcuate segment (5) is fixedly attached to the cylinder (3) and has a toothed surface portion and a threaded opening for receiving a tie rod fastener (16). A tubular housing (7) encircles the cylinder (3) and the arcuate segment (5). The pinion (6) is engageable with the toothed surface portion of the arcuate segment (5) within the housing (7).

Abstract: A lightweight housing (12) for a hydraulic power steering gear (10) includes a tubular structure (34 or 68) with a longitudinal central axis (21 or 23). The tubular structure (34 or 68) has layers extending circumferentially around the axis (21 or 23), including an inner layer (100), an outer layer (102), and an intermediate layer (104) between the inner and outer layers (100 and 102). The inner layer (100) is formed of plastic material. An inner surface (118 or 120) of the inner layer (100) defines an outer boundary of a space (36,38 or 88) containing hydraulic fluid under pressure. The outer layer (102) is formed of metal material. The intermediate layer (104) is formed of elastomeric material, and is compressively loaded radially between the inner and outer layers (100 and 102).

Abstract: A power steering apparatus is composed a fluid source for discharging pressurized fluid, a power cylinder, a control valve responsive to operation of a steering wheel for supplying the power cylinder with pressurized fluid from the fluid source, and a reservoir. The control valve has a first control portion for controlling the flow of pressurized fluid from the fluid source to the reservoir, and a second control portion for controlling the flow of pressurized fluid to the power cylinder. The first control portion has four paths communicating with the fluid source and the reservoir, and each of the four paths is formed with a center-open variable orifice which opens when the control valve is in a neutral state.

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.