131results about "Hydraulic steering gears" patented technology

The present invention relates to a zero turning radius vehicle having at least one steerable front wheel and a multistage steering input system separately capable of steering the at least one front wheel and selectively driving the drive wheels. A front wheel steering system comprises at least one oblongated sprocket meshingly connected to a steering shaft. An engagement cam system provides the ability to selectively, independently couple the steering wheel to pump arms driving a first and second drive wheel. A steering cam shaft comprises at least one steering cam that acts on at least one bearing. Once the engagement cam system rotates the at least one bearing into place to receive the at least one steering cam, rotation of the steering cam independently alters the speed of one drive wheel in relation to the other drive wheel in response to steering input provided by the operator.

A vehicle steer by wire system which has a steering wheel for setting a desired turn angle of a vehicle wheel, a steering wheel turn sensor for sensing the desired turn angle, a hydraulic steering actuator for turning the wheel, a wheel turn sensor for sensing the current wheel turn angle and a control unit for receiving the desired turn angle and current wheel turn angle signals. An electronically controlled steering actuator control valve means is provided for supplying pressurized fluid to the steering actuator via a steering circuit in response to signals from the control unit to turn the wheel to the desired turn angle. A hydraulic motor connected with the steering wheel is provided to provide steering feedback to the steering wheel via a feedback circuit which includes an electrically controlled hydraulic feedback control valve means which directs fluid to and from the hydraulic motor in response to the signals from the control unit to generate the steering feedback. The steering system has a fail-safe mode in which fluid pressure from the hydraulic motor provides steering of the wheel in the event of a failure to electronically actuate the steering actuator control valve means.

The invention discloses a full-hydraulic steering system of a double front-axle passenger step. The front part of a frame is provided with a first steering axle and a second steering axle, and a full-hydraulic steering follower and a middle swing arm are arranged between the first steering axle and the second steering axle, wherein the full-hydraulic steering follower is arranged on the external side of a longitudinal beam of the frame. The front end of a first pull rod is hinged with a steering knuckle arm bulb of the first steering axle, and the rear end of the first pull rod is hinged with the lower part of the middle swing arm. The front end of the second pull rod is hinged with the lower part of the middle swing arm, and the rear end of the second pull rod is hinged with a steering knuckle arm bulb of the second steering axle. The full-hydraulic steering system of the double front-axle passenger step adjusts the original single front-axle steering system into the existing double front-axle steering system, so that the defect that the load of the original single front-axle steering system is large can be favorably overcome. Moreover, the full-hydraulic steering system of the double front-axle passenger step adopts the middle swing arm to drive the steering knuckle arms of the first steering axle 2 and the second steering axle 3 to rotate synchronously. The full-hydraulic steering system of the double front-axle passenger step has the advantages of simple structure and easiness in construction.

A closed-circuit pump is provided that receives input from a steering unit in order to drive a steering cylinder. The closed-circuit pump is preferably a proportional bi-directional pump. The steering unit includes a steering wheel or similar device controlled by an operator. In one embodiment, the steering unit is a conventional hydraulic system that includes a servo pump. In another embodiment, the steering unit is an electronic displacement control system. The steering cylinder engages with a steering assembly to perform the steering function by physically turning the wheels of the vehicle. The inlet of the steering cylinder includes a counterbalance valve, which prevents flow into the steering cylinder when there is no steering input from the operator.

The invention relates to a hydraulic steering gear, belonging to the technical field of hydraulic transmission and control. One end of the valve body of the steering gear is fixedly connected with a stator with a cycloidal pin wheel rotor. A spool which stretches out of a front shaft and a valve pocket which can form a runner switching valve together with the spool are arranged in the valve body. A linkage shaft penetrates through the inner hole of the spool. One end of the linkage shaft is provided with outer teeth which are engaged with a spline in the rotor, and the other end of the linkage shaft is connected with the spool through a radial shifting pin. An annular sealing groove is arranged on the surface of the inner hole of the valve body which is matched with the front shaft. An annular sealing skeleton made of a lubricating wear-resistant material is installed in the sealing groove. One surface of the sealing skeleton is in fit with one sealing surface, and the other surface of the sealing skeleton is provided with a groove which can hold a sealing ring. An elastic sealing ring which is in fit with the other sealing surface is arranged in the groove. On the premise that a good sealing effect is guaranteed, the input torque for power steering is effectively reduced.

The invention relates to a hydraulic centering cylinder with a mechanical lockup function and belongs to the field of automobile steering systems. The hydraulic centering cylinder comprises an oil cylinder body, a piston rod, a left oil cylinder end cover, a right oil cylinder end cover, a left floating piston, a right floating piston, a spring, lockup pistons and nuts. The installation method of the hydraulic centering cylinder includes that the spring is strung in axis through holes of the two lockup pistons which are vertically and symmetrically arranged, then the integrated spring and lockup pistons are placed in a groove of an annular boss of the piston rod, and finally, two ends of the spring are tensioned by the nuts to finish assembling. By means of extension and retraction of the two lockup pistons, integration and separation of the piston rod and a cylinder body through relative movement are achieved, and accordingly, mechanical lockup and unlocking of the piston rod during movement are achieved. By means of mechanical lockup, slight moving of the piston rod under large impacting is prevented, and simultaneously, safety guarantee is provided for hydraulic centering. When unlocking is required, only working oil pressure is required to be removed, and the lockup pistons are automatically retracted to the groove of the annular boss of the piston rod to finish unlocking under the action of spring forces.

A closed-circuit pump is provided that receives input from a steering unit in order to drive a steering cylinder. The closed-circuit pump is preferably a proportional bi-directional pump. The steering unit includes a steering wheel or similar device controlled by an operator. In one embodiment, the steering unit is a conventional hydraulic system that includes a servo pump. In another embodiment, the steering unit is an electronic displacement control system. The steering cylinder engages with a steering assembly to perform the steering function by physically turning the wheels of the vehicle. The inlet of the steering cylinder includes a counterbalance valve, which prevents flow into the steering cylinder when there is no steering input from the operator.

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

The invention relates to an articulated field operation vehicle chassis, comprising a front vehicle frame, a two-degree-of-freedom articulated mechanism, a hydraulic steering mechanism and a rear vehicle frame, the front vehicle frame is connected with the rear vehicle frame through the two-degree-of-freedom articulated mechanism and the hydraulic steering mechanism, the front vehicle frame and the rear vehicle frame adopt dual-U-shaped frameworks, the two-degree-of-freedom articulated mechanism and the hydraulic steering mechanism realize the longitudinal oscillation along the vehicle frame direction between the front vehicle frame and the rear vehicle frame and the transverse rotation along the direction of a plumb shaft; and the articulated chassis adopts a wheel-side hydraulic driving device for constituting a four-wheel full-driving system, thereby improving the off-load driving performance and the traction performance of the articulated chassis. The articulated field operation vehicle chassis adopts the four-wheel full hydraulic driving system, the dual-U-shaped frameworks and the two-degree-of-freedom articulated mechanism, thereby not only having the off-load driving performance which is applicable to complicated field terrain environments, but also having good traction performance, flexible mobility and road adaptability, thereby further being capable of meeting the filed operation requirements and being particularly applicable to military filed material handling and other filed operations.

The invention discloses an automobile active steering system with a cycloidal-pin wheel mechanism, and aims at overcoming the contraction between light steering effort and flexibility. The automobile active steering system comprises a steering hand wheel (47), a steering shaft (52), a steering transmission shaft (48), a cycloidal-pin wheel type transmission mechanism (49), a rotary hydraulic valve (50), and a steering box (51). The steering hand wheel (47) is connected with an upper end of the steering shaft (52) by use of a spline pair, a lower end of the steering shaft (52) is connected with an upper end of the steering transmission shaft (48) by use of a universal joint, a lower end of the steering transmission shaft (48) is connected with a right end of an input shaft (21) of the cycloidal-pin wheel type transmission mechanism (49) by use of a universal joint.

A hydraulic steering system (1) is described comprising a first steering circuit (2a) and a second steering circuit (2b), each of said steering circuits (2a, 2b) comprising a steering device (3a, 3b) and a steering motor (4a, 4b) connected to said steering device (3a, 3b), each of said steering devices (3a, 3b) comprising a supply port arrangement having a high pressure port (Pa, Pb) and a low pressure port (Ta, Tb), a working port arrangement having two working ports (La, Ra; Lb, Rb) connected to said steering motor (4a, 4b), a control valve (5a, 5b), and a measuring motor (6a, 6b). Such a steering system should have a comfortable steering behavior. To this end in each of said steering devices (3a, 3b) said measuring motor (6a, 6b) is arranged in a working line (19a, 20b) between said control valve (5a, 5b) and one of said working ports (La, Ra; Lb, Rb).

The mechanical transmission of the vehicle all adopts hydraulic transmission. A walking part of the vehicle adopts a single coupling shaft and a double coupling shaft and forms the situation of being wheel-by-wheel and power-by-power (four-wheel and four-drive). A front shaft is a single coupling shaft, an arch bridge is upward and the central part is provided with a vertical shaft. The function of the vertical shaft is to move two wheels from transverse to consequent to 90 degrees, the wheels rotates under stress application, the vehicle body can be pulled, a back wheel is taken as a central point to change the front of the vehicle into the back thereof, thus completing 180-dgree turn and ensuring that the vehicle takes place exactly and returns back to the cultivated direction and position after the turn. A back shaft is the double coupling shaft. In order to reduce water loss and soil erosion and increase the buffering power of soil against rain water, the cultivation crossing to mountains is adopted for hilly lands. Therefore, the vehicle body can be inclined to heavier side when cultivating the hilly lands, the weight of the vehicle body is moved to low wheels and the high wheels losing gravity and adhesion to the ground slide and idle, thus causing the phenomenon of deviating from a cultivation ridge path or not walking of a rotary vehicle and bringing great difficulty for implementing mechanization. Consequently, in order to adapt the cultivation in a mountain area, the middle position of the length of the vehicle body is specially and additionally provided with a sliding iron counterweight accounting for 30 percent of the total weight of the vehicle body. When the vehicle cultivates the hilly lands transversely, the sliding iron counterweight can correspondingly move to a higher position under the control of a vertical automatic switch and presses the weight on the high wheels so as to lead the gravities of high and low wheels to be the same or similar.

The invention relates to a vehicle whole hydraulic pressure turn driving axle comprising vehicle bridge shell, knuckle hinged with the two ends of the vehicle bridge shell, hydraulic motor coupled with the knuckle, bicycle brake and packing brake, characterized in that the two ends of vehicle bridge shell are hinged with the knuckle by the up and down free bearing, wherein the up free bearing is hinged with the knuckle by the high pressure rotating joint, a double-piston rod hydraulic cylinder is mounted in the middle of the vehicle bridge shell, wherein the cylinder body of the double-piston rod hydraulic cylinder is coupled with the vehicle bridge shell and the two rod ends of the piston rod of the double-piston rod hydraulic cylinder are hinged with the steering arms of left and right end and the other end of the steering arm is respectively hinged with the two ends of the knuckle, and the knuckle is driven to sway along the up and down free bearing of the vehicle bridge shell. The invention has features of simplicity, reasonableness, high power density ratio, big starting torque, slow running, small turning radius, good performance, more reliable linkup of the hydraulic piping, better usage and sealing performance.

The invention relates to a full-hydraulic wheel multi-motor independent-drive system, in particular to the application shunt and hydraulic resistance control technology to realize a system for traction balance drive control for each wheel of a full-hydraulic vehicle. A full-hydraulic multi-wheel independent-drive traction balance control system comprises an engine, a duplex variable piston pump, a manual pilot valve, an electromagnetic reversing valve and in-wheel hydraulic motors; the hydraulic elements are connected through hydraulic pipelines; the system is characterized by further comprising a shunt (5) and a throttling device (4); the shunt (5) is fixed on a vehicle frame; the inlet of a hydraulic loop is connected with the duplex variable piston pump (9), and the outlet is connected with the in-wheel hydraulic motors (1) on one side through the electromagnetic reversing valve (3) respectively; and the throttling device (4) is installed between adjacent in-wheel hydraulic motors (1) at the outlet of the shunt (5).

The invention discloses a forklift steering balancing device which includes an oil box, a full hydraulic steering device and two oil cylinders. The oil outlet of the oil box is connected with the pressure oil inlet of the full hydraulic steering device by an oil pump; the oil inlet of the oil box is connected with the return opening of the full hydraulic steering device by a filter. The forklift steering balancing device is characterized in that the rod-free cavity of one oil cylinder is communicated with the rod cavity of the other oil cylinder by a pipeline; while the rod cavity and the rod-free cavity of the two oil cylinders are respectively communicated with one working oil opening of the full hydraulic steering device. The two ends of the piston of each oil cylinder are provided with blind holes used as valve cavities; all the blind holes are provided with a valve consisting of a top rod, a spring and a spherical valve core. The outer end of the top rod extends out of the corresponding end of the piston. A radical hole is arranged between the two blind holes; the two ends of the radical hole are respectively communicated with the two blind holes. The forklift steering balancing device can be used for reducing the walking resistance of the forklift and ensuring the forklift can work normally. Besides, the forklift steering balancing device can be used for controlling the steering of the two front wheels of the forklift.