Showing papers on "Hydraulic machinery published in 1985"

Full hydraulic power steering system

Abstract: A full hydraulic power steering system for a forklift truck is disclosed wherein in order to correct the position of a steering wheel in relation to an actuator for a steered wheel, hydraulic fluid is discharged from a portion of hydraulic fluid line means interconnecting a steering unit operable by the steering wheel and the actuator.

Cavitation Phenomena and Performance of Oil Hydraulic Poppet Valve : 1st Report, Mechanism of Generation of Cavitation and Flow Performance

Abstract: By using an unique half cut model of an oil hydraulic poppet valve, the cavitation phenomena were directly observed and the pressure distribution was measured in the metering restriction between the valve seat and the poppet surface. As a result of this research, the occurrence process of cavitation in a poppet valve and the effects of it on the flow performance were made clear. Also, the differences in a performance of cavitation between the diverging flow and converging flow were understood.

Furrow opener operating apparatus

Abstract: There is described a furrow opener apparatus capable of operating in a furrowing mode and a carrying mode. The apparatus consists of a double acting hydraulic cylinder having one end connected to a furrow opener drag arm and the other end connectable to a drill rig. It incorporates a pressure cushioning system consisting of at least one pressure absorber and hydraulic lines communicating through a mode valve with both the thrust and draw sides of the double acting cylinder. It further communicates through a single or double acting hydraulic valve to the hydraulic pump and reservoir of an associated prime mover such as a tractor. The mode valve is hydraulically connected to both the thrust and draw sides of the double acting cylinder. In a first mode the mode valve is hydraulically connectable to the pressure cushioning system and in a second mode hydraulically connected through a double acting hydraulic valve to the hydraulic pump and hydraulic reservoir of the prime mover. In use when the mode valve is in the first mode the pressure absorber cushions forces transmitted hydraulically through the double acting hydraulic cylinder from the openers and maintains a substantially constant pressure on both the draw and thrust sides of the double acting cylinder to thereby create a net downward force from the ram onto the furrow opener arm. In the second mode the double acting hydraulic cylinder is operable by the double acting hydraulic valve to thrust or draw its ram to respectively lower or raise the furrow opener drag arm.

Anti-roll system for a vehicle

Abstract: First and second cross-bars extend laterally across the width of a vehicle and are pivotally connected intermediate their lengths in scissors fashion. One end of each cross-bar is pivotally connected to a wheel support assembly which is in turn pivotally connected to the vehicle body by a spring and damper assembly. The other end of the first cross-bar is pivotally connected to the vehicle body by a hydraulic cylinder and piston assembly. The other end of the second cross-bar is pivotally connected via a lever to the actuator of a variable flow hydraulic valve. Lateral forces exerted by the wheels and cross-bars relative to the vehicle body during a turn operate the hydraulic valve to send a proportionate amount of hydraulic fluid to the upper or lower portion of the hydraulic cylinder to thereby prevent rolling of the vehicle body.

Power assisted steering system

Abstract: A power assisted steering system of the type which includes a hydraulic reaction mechanism for controlling the hydraulic power assist in accordance with an increase or decrease of the vehicle speed. The system includes primary and secondary hydraulic pumps, the primary pump having the function of applying hydraulic pressure to the power cylinder and the secondary pump having the function of applying hydraulic pressure to the reaction mechanism in proportion to the vehicle speed. The secondary pump is unitedly assembled with the primary pump to be driven by the prime mover, and comprises a first control valve for controlling the quantity of fluid applied to the reaction mechanism for the secondary pump in a constant amount, and a second control valve for controlling the pressure of fluid controlled by the first control valve in accordance with the vehicle speed.

Control apparatus for hydraulic motor

Abstract: A control apparatus for a hydraulic motor for use in a construction vehicle driven by hydraulic power has a hydraulic motor, a hydraulic pump serving as a pressurized fluid supply source, a manually operable directional control valve connected across supply and discharge conduits for the hydraulic motor, a brake valve section including a counterbalancing valve and a pair of relief valves all of which are connected across the conduits extending between the directional control valve and the hydraulic motor, and a selector valve for controlling the supply of control pressurized fluid introduced through a shuttle valve connected across the conduits into a displacement control cylinder contained in the hydraulic motor. The selector valve is of a pilot operated type remotely controlled by pilot pressurized fluid supplied from an external pressurized fluid supply source.

Hydraulic power piping unit for a lift truck

Abstract: A lift truck having a hydraulic power piping unit for interconnecting between a control valve unit and a hydraulic actuator, mounted and encased in a full free lift upright assembly arranged in front of the truck body. The piping unit has a first pulley unit held by a middle tie beam of the vertically liftable inner masts, for guiding one assembly of flexible hydraulic hoses hanging down in a loose U-shape and connected to the control valve unit. The piping unit also has a second pulley unit held coaxially with a chain wheel on a top of a piston rod of a free lift cylinder mounted on the middle tie beam of the inner masts, for supporting the other assembly of flexible hydraulic hoses connected to the hydraulic actuator. The one and the other assemblies of flexible hydraulic hoses are fluidly connected to one another by a hydraulic joint unit held by the middle tie beam.

Water-powered hydraulic motor

Abstract: A hydraulic power system for operating a rotary-hydraulic motor includes a pair of hydraulic piston/cylinder assemblies each disposed in vertical disposition below a common water source and having cylinder heads interconnected by hydraulic delivery and supply conduits in a closed circuit including the motor which is operated by forward and reverse flow of liquid through the circuit effected by alternative rising and lowering of the respective pistons. The upper ends of the respective pistons are provided with water tanks which are filled from the water source and emptied into respective discharge tanks sequentially to provide the raising and lowering movements of the pistons. The system further includes various valve devices in the closed hydraulic circuit and in association with the water source and piston and discharge tanks for controlling the respective liquid flows in a manner providing the cyclical alternative reciprocation of the respective pistons.

Control apparatus for double acting hydraulic cylinder units

Abstract: A cylinder unit is supplied with pressurized fluid from a hydraulic machine which is variable in speed and/or displacement. The machine may be operated as a pump and as a motor to increase the pressure or, respectively, to decrease the pressure so that the piston of the cylinder unit may be actuated in both directions and, furthermore, the brake energy is recovered by the machine when the piston is driven through an external load. This results in an increased efficiency of the control apparatus for the cylinder unit avoiding any problems arising from heat.

Hydraulic tool system

Abstract: A system of hydraulic tools utilizing removably, replaceable and substantially interchangeable valve assemblies, fluid reservoirs and hydraulic driving mechanisms. The fluid reservoir maintains the hydraulic fluid under moderate pressure. The valve assembly can contain a hydraulic pump for powering the driving mechanism. The hydraulic pump preferably has displacement varying means for changing the power transfer ratio of the pump. The hydraulic assemblies are removably received in a variety of tool bodies.

Device for generating sound pulses inside a well, by percussion

Abstract: A device for generating sound pulses in a well by a mobile mass striking against a target element integral with an elongate body anchored in a well by retractable shoes actuated by hydraulic cylinders. The mobile mass which slides in a first chamber in the body is moved away by a piston moving in a second chamber of the body and intermittently locked in the moved away position by a valve. The piston, the valve and also the hydraulic cylinders acting on the anchorage shoes are actuated by a hydraulic system which may be remote controlled from the surface.

Two stage, pressure-compensated hydraulic control device for at least two consuming units

Abstract: The invention relates to two-stage, pressure-compensated hydraulic control devices, which function independently of the load, and which feed a plurality of consuming units from one source - a pump. Each consuming unit has a proportional way valve, which is designed as a two-stage flow booster which comprises a control element and an booster stage. The control stage may be designed as a slide displaceable in a valve body, which slide is displaced in the valve body, with primary and secondary profiles which together form flow boosters and are arranged on the one sides of the consuming ducts, and brake profiles which are arranged on the other sides of the consuming ducts. The control device may be constructed as a control member and perform the function of the proportional way valves or be equipped with metering units and perform the function of servomechanisms. The control device according to the invention enables the hydraulic systems on many mobile machines to be simplified and the costs reduced.

Portable hydraulic power unit

Abstract: A hydraulic power unit includes an engine and a pump mounted to a portable frame having an integral fluid reservoir for circulating the hydraulic fluid. Detachably mounted to the frame is a multiple speed winch. The fluid reservoir within the frame comprises the hollow structural tubing of the frame itself. The frame includes a handle for carrying the unit while the winch is in operation and for providing a hydraulic head to the pump and an expansion chamber for the hydraulic fluid. The multiple speed winch includes, in addition to the hydraulic motor, a first rotatable shaft and a second rotatable shaft operatively connected to the motor for providing two speeds to the winch. Each shaft has a freely rotatable hub mounted thereon which is engaged to its shaft by an associated clutch. By engaging and disengaging the clutches, the hydraulic motor may drive either of the shafts directly to reel in the attached cable or play it out.

Measuring and indication fluid pressure and flow rate in a pneumatic or hydraulic system

Abstract: For occasional measurements of fluid pressure and temperature and flow-rate in a pneumatic or hydraulic system, a sensor 1 is permanently installed in the system for a hand-held readout module 6 to be occasionally connected to it. More particularly, flexible pressure tubes 4 and 5 can be connected by quick-acting fluid couplings at 2 and 3 to pressure tappings in sensor 1, to apply differential pressure to a gauge 7 and full system pressure to a gauge 9, whilst a temperature capillary tube 14 connects a temperature gauge 8 to a sensing bulb applied at 18 to the sensor body.

Rotary cellular pump for hydraulic systems

Abstract: The invention relates to a rotary cellular pump, preferably for feeding hydraulic systems, the term rotary cellular pumps referring to all pump types having revolving cells In order to prevent disruptions in the case of intermittent operation or operation at different rotational speeds, a plurality of outlet bores is disposed between the dead-centre positions, which outlet bores are safeguarded by non-return valves and each of which preferably opens into a plenum

Downhole resettable formation sampling tool

Abstract: A tool for use downhole has means (18, 19, 20, 44) for engaging materials surrounding the hole The engagement means (18, 19, 20, 44) are operated by hydraulic pressure controlled by a hydraulic circuit (10) A hydraulic power module (11) is provided for varying hydraulic pressure in the hydraulic circuit (10) to effect movement of the engagement means (18, 19, 20, 44) In case of failure, a dumping assembly (17) is provided to allow relief of hydraulic pressure in the circuit (10) The dumping assembly (17) includes a dump chamber (62) of variable volume, a dump valve (60) and a non-return valve (61); the hydraulic circuit being capable of being re-set downhole after dumping, there being no need to bring the tool to the surface

Marine propulsion device hydraulic system

Abstract: A marine propulsion device comprising a propulsion unit adapted to be pivotally mounted on the transom of a boat for pivotal movement relative to the transom about a steering axis, the propulsion unit including a rotatably mounted propeller, an engine including a throttle lever, and a shiftable transmission drivingly connecting the engine to the propeller and including a shift lever, a hydraulic shift assist system connected to the shift lever for actuation thereof, a hydraulic throttle assist system connected to the throttle lever for actuation thereof, a hydraulic fluid reservoir, a pump communicating with the reservoir, a supply conduit communicating between the pump and the shift assist system, a supply conduit communicating between the shift assist system and the throttle assist system, and a return conduit communicating between the throttle assist system and the reservoir.

Device for monitoring or controlling the auxiliary pressure in a hydraulic system

Abstract: To monitor and/or control the auxiliary pressure in the supply system of a hydraulic system, in particular a braking system, a device is proposed which has a pressure sensor (15, 15') which essentially consists of piezoelectric, piezoresistive or capactive pressure transducers which are connected to an electronic measuring and analysing circuit (34, 35). To this end, the pressure sensor (15, 15') is arranged in the gas-filled chamber (24) of a hydraulic accumulator (17, 17') or in a space (27, 32') attached to this chamber so that it cannot come into contact with the pressure-transmitting means.

Method and device for control of variable speed hydraulic machine

Abstract: PURPOSE:To improve the stabilizing degree of dynamic condition of electric power system by controlling a guide vane in accordance with the fluctuation of frequency of the electric power system side or the fluctuation of the electric power. CONSTITUTION:When an electric power detector 16 detects that the supply and demand condition of the electric power in the electric power system 5 is changed, an output setting signal Px is corrected through a fluctuating rate operating device 17 and a passive state element 18. For this purpose, the commanding value Yx of a function generating device 4 is corrected automatically in increasing or decreasing direction temporarily, the guide vane 11 is operated so as to be opened or closed through a PID computer 15 and an amplifier 10 and, accordingly, the output of a pump waterwheel 2 follows in a direction mitigating the condition of demand and supply of the electric power.

Hydraulic system for a steerable vehicle with battery-supplied electrical drive

Abstract: Hydraulic system for a vehicle with battery-supplied electrical drive with hydraulic power steering device and a plurality of loads of hydraulic energy which take up energy streams of different sizes, and having two electric motor/pump assemblies of different sizes and having a priority valve, only the smaller electric motor/pump assembly 1/2 being switched on when only a small flow is required in order to save energy and its feed flow being directed via the priority valve 6 to the feedline 15 of the larger pump 12, the adjustment devices 23 and 24 of the two electric motors 13 and 1 and a releasable valve 22 and, if possible, a pressure accumulator 27 and pressure shut-off valve 30 being connected by a circuit.

Cooling system for electrical machine

Abstract: A hydraulic circuit branch of a cooling system in thermal contact with the stator winding of a hydraulic power generator is provided with a feed tube divided into two separate input tube sections. The downstream ends of the input tube sections are connected to respective multiplicities of subsidiary hydraulic circuit branches in the form of winding bars via a pair of semicircular manifolds. The current throughput through the winding bars is monitored by determining the difference between the rates of coolant flow through the approximately identical input tube sections. If the rates of coolant flow or throughputs in the input tube sections differ from one another by an amount which itself differs from a predetermined reference value by more than a preselected threshold, a warning signal is generated indicating that heat removal from the hydraulic power generator is being impaired.

Press for processing work pieces made from metal

Abstract: 1. A press (20) for the machining of workpieces made of metal (1) in several successive machining stations with shaping tools (25) consisting of an upper and a lower tool arranged in these machining stations, wherein all upper and/or lower tools can be charged commonly by a press ram of the press hydraulic mechanism, and with a device (10) for automatically conveying the workpieces (1) from machining station to machining station after each press stroke, characterized in that, in at least one machining station, the tool is constructed as a fineblanking tool in whose upper part (2) and lower part (3) there is installed a respective hydraulic block (4, 4') as upper structure and lower structure of the tool insert (17, 18) and as an auxiliary hydraulic system for fineblanking, wherein each hydraulic block (4, 4') together with the appropriate tool insert (17, 18) is inserted in an upper or lower quick change frame (6, 6') and can be driven by its own driving means (56, 19, 44).

Hydraulic brake system for automotive vehicles

Abstract: A hydraulic brake system for automotive vehicles with a master brake cylinder and with a hydraulic power booster (1) connected upstream of the master brake cylinder, in which a pressure medium pump (6) drivable by an electric motor (9) is employed for providing auxiliary hydraulic energy. The drive of the pressure medium pump (6) may be switched on by a pressure contact (13) of a pressure accumulator (4), on the one hand, and by a brake pedal contact (11), on the other hand. In the unbraked operation of the automotive vehicle, the pressure medium accumulator is permanently kept on a pressure level sufficient for an initial actuation of the brake. A valve assembly is provided which establishes a hydraulic connection between the outlet of the pressure medium pump (6) and the pressure port of the hydraulic power booster (1). An electromagnetically actuatable two-way/two-position directional control valve (5) is connected to the valve assembly (7), which valve (5) is normally open and which is adapted to be switched to its closed position by a brake pedal contact (11).

Directional control valve and regeneration valve

Abstract: An hydraulic system for operating double acting piston/cylinder assemblies and for effecting automatic transition from a regenerative mode of operation of a double acting piston/cylinder assembly to a non-regenerative mode of operation thereof. Pressure responsive valve means automatically converts the hydraulic system from one initially being a high-speed/low force operation to a high force/low speed operation.

Rear wheel steering control device

Abstract: PURPOSE:To prevent an abrupt change of the car body attitude while a vehicle is running by prohibiting rear wheel steering even when car speed sensors fail as well as a car speed exceeds a fixed car speed value. CONSTITUTION:A rear wheel steering controller 32 is invariably fed with car speed detection signals from the first and second car speed sensors 26, 28. When the running car speed exceeds a fixed car speed, it feeds a hydraulic valve transfer signal for prohibiting rear wheel steering to a rear wheel steering hydraulic control valve 17. In addition, a hydraulic circuit to a rear wheel steering hydraulic cylinder 20 is cut off, and a piston rod 21 is locked at a neutral position. When car speed sensors 26, 28 fail, if it is judged that car speed detection signals having a difference of a predetermined value or more are output, a car sensor failure is judged. Then, the piston rod 21 of the rear wheel steering hydraulic cylinder 20 is locked at a neutral position, and rear wheel steering is wholly prohibited.

Arrangement for elevating liquid by use of solar and/or wind energy

Abstract: An arrangement for elevating liquid by the use of solar and/or wind energy having a pipe immersed in a liquid, a pipe directed upwardly from the surface of liquid and interconnection for entrapment of liquid, with a pressure differential and an air passage formed alternately and repetitively during presence of solar and/or wind energy, is additionally provided with an air purging element formed as a hydraulic valve with upper and lower interconnected pipes of which the upper pipe has an outlet located above the liquid level.

A Study of Pressure Fluctuations in the Suction Lines of Positive Displacement Pumps

Abstract: This paper is a contribution to the understanding of the generation and transmission of pressure ripples in hydraulic systems. Previous research on fluid-borne pressure fluctuations in hydraulic sy...

Composite hydraulic system

Abstract: A composite hydraulic system for a work vehicle which has two separate hydraulic circuits. Included in the composite system are three pumps, two of which supply the two circuits on the vehicle. A third pump transfers hydraulic fluid between the two hydraulic circuits. An engine operates all three pumps simultaneously and means are provided whereby the third pump under certain conditions operates as a motor to provide regeneration.