Showing papers on "Hydraulic machinery published in 1970"

Determination of the post-failure behavior of brittle rock using a servo-controlled testing machine

Abstract: Determination of the Post-Failure Behavior of Brittle Rock Using a Servo-Controlled Testing Machine. The use of the servo-controlled testing machine to control fracture when a rock specimen is deformed beyond its peak strength is discussed. This region of deformation can not usually be examined because excess energy released by the loading system produces rapid disintegration of the specimen. In the test method described the energy release is controlled by a high frequency electronic servo-control system acting in combination with a hydraulic system of very short response time. The control causes the excess energy to be withdrawn before it can be released into the disintegrating specimen, by removing pressurized fluid from the hydraulic system. Theoretical considerations reveal that the condition for controlled fracture is determined by the ability of the hydraulic loading system to unload rapidly. This may be expressed in terms of a ‘dynamic stiffness’,K r , of the hydraulic system. For sufficiently small deformation rates and short servo-control response times the fracture process can be controlled, even though the unloading slope of the stress-strain curve of the rock specimen tends to become infinitely steep. The experimental technique is described in detail and some results obtained in studying the post-failure behavior of Tennessee Marble under uni-axial and bi-axial compression using the new system are presented.

Hydraulic system and valve therefor

Abstract: A two-pump hydraulic system having a hydraulic load which, when actuated, is automatically pressurized by both pumps through a novel valve system. Normally each of the pumps circulates hydraulic fluid along a closed path to a reservoir and can be used independently to operate respective loads.

Bore hole seismic transducer

Abstract: A vibrational seismic source device adapted to be lowered in a well bore. The vibrator essentially comprises a volume booster operating an expandable bellows-type source connected between two pistons biased against opposite walls of the bore hole. The volume booster is driven by a hydraulic amplifier which in turn is controlled by a servo hydraulic valve. The hydraulic vibratory system is centered and retained in the well bore by utilizing a packer arrangement totally surrounding the vibrator and adapted to be expanded against the bore hole. A high pressure, high volume hydraulic source is provided up hole and operationally connected to the servo valve, volume booster, and biasing means.

Hydraulic system for a boat drive

Abstract: A hydraulic system for steering and tilting an outboard drive unit for a boat including a pump, a steering sub-system including a double acting cylinder and piston connected to provide steering movement to a steerable part of the unit and provided with hydraulic liquid from the pump, and a trimming and tilting subsystem including a cylinder and piston assembly provided with liquid from the steering sub-system. Manual valves control tilting and trim positioning of the unit, and steering, while pressure relief valves are arranged to prevent damage to the unit and system upon excess steering control, striking of external objects, and the like.

Functional fluid compositions containing perfluoro surfactants

Abstract: PHOSPHATE ESTER BASED FUNCTIONAL FLUID COMPOSITIONS CONTAINING SMALL AMOUNTS OF PERFLUORINATED ANIONIC SURFACTANTS ARE NOVEL COMPOSITIONS OF MATTER WHICH WHEN EMPLOYED AS HYDRAULIC FLUIDS IN HYDRAULIC SYSTEMS SHOW INCREASED ABILITY TO INHIBIT EROSION OF MATERIAL AND DAMAGE TO MEMBERS IN SUCH HYDRAULIC SYSTEMS.

Means for performing gear changes in multi-ratio change-speed gear boxes

Abstract: A hydraulic gear-changing apparatus having a gear-box having driven members, driving members and members to be moved to selectively engage a driven member and a driving member is provided with a hydraulic assembly for changing the speed of the driving member prior to engagement with the member to be moved, the hydraulic system comprising a pump, an electromagnetically operated three position four-way valve and means for fluid connection of the pump to the four-way valve, a fluid source and a fluid return sump including a by-pass between the fluid source and fluid return sump, the hydaulic assembly braking the driving member, driving the driving member or operating without effect on the speed of the driving member depending upon the position of the four-way valve.

Central hydraulic system for a vehicle

Abstract: In a vehicle having an automatic transmission and power steering, there is provided a central hydraulic system wherein the power steering and transmission control systems are connected in series to receive the fluid from a single pump when pump flow is low and are connected in parallel to receive fluid from the pump when pump flow is high.

Adjustable hydraulic/electric hand grip dynamometer

Abstract: A hand-grip dynamometer having a main support element mounting front and back grip members in spaced relation on opposite sides thereof, and incorporating a hydraulic system interconnected with the front grip member and combined with a potentiometric pressure transducer for measuring a gripping force applied to the front grip member.

Hydraulic solenoid valve directly operated with adjustable over-ride speed

Abstract: A hydraulic valve is operated by an electromagnet which is enclosed in a tight chamber and actuates a core movable in a cylinder, said core being provided with longitudinal perforations through which the liquid governed by the valve passes as the core moves through said cylinder; the section of the perforation may be adjustable for regulating the speed of the core in the cylinder.

Method and device for damping flow pulsations in a hydraulic system

Abstract: A method and device for damping flow pulsations in a liquidphase flow supplied under pressure from a conventional hydraulic pump or the like, which method comprises dividing the supplied pulsating flow into two separate flow components, causing the flow components to impinge upon each other in an enclosure so as to cancel the pulsating energy in the two flow components, and withdrawing the pulsation-free pressurized flow out of the enclosure, whereby a pressurized flow cleared of pulsations can be supplied to a hydraulic system such as an automotive power steering system.

Hydraulic system for supporting a harvester platform

Abstract: A SELF-PROPELLED WINDOWER HAVING WHEELED FRAME AND A HARVESTER PLATFORM DISPOSED FORWARDLY OF THE FRAME FOR CUTTING ANS SWATHING A CROP. THE PLATFORM IS MOVABLY MOUNTED ON THE FRAME AND IS FLOATABLY SUPPORTED BY A HYDRAULIC SYSTEM ENABLING THE PLATFORM TO MOVE UPWARDLY AND DOWNWARDLY IN ACCORDANCE WITH GROUND UNDULATIONS.

Gas turbine power plant

Abstract: A POWER PLANT HAVING A GAS TURBINE ENGINE WITH SEPARATE GAS GENERATOR AND POWER TURBINE SECTIONS, A TRANSMISSION WITH INPUT AND OUTPUT SHAFTS CONNECTED BY DIFFERENTIAL GEARING, A HYDRAULIC POWER TRANSFER LOOP, AND POWER TRANSFER MEANS BETWEEN THE ENGINE AND THE TRANSMISSION. THE POWER TRANSFER MEANS HAS A FIRST SET OF POWER TRANSFER PATHS SELECTIVELY CONNECTING THE POWER TURBINE WITH THE INPUT SHAFT, AND A SECOND SET OF POWER TRANSFER PATHS SELECTIVELY CONNECTING THE GAS GENERATOR SECTION WITH OTHER PARTS OF THE TRANSMISSION. BOTH POWER TRANSFER PATHS OF EACH SET HAVE GEAR REDUCTION TRAINS OF DIFFERENT RATIOS. CLUTCH MEANS SERVE TO SELECTIVELY RENDER CERTAIN POWER TRANSFER PATHS OF EACH SET EFFECTIVE AT PREDETERMINED TIMES DURING THE OPERATION OF THE POWER PLANT. A HYDRAULIC POWER TRANSFER LOOP, WITH COMBINATION PUMP AND MOTOR COMPONENTS IN MOTIONTRANSMITTING RELATION WITH ELEMENTS OF THE TRANSMISSION AND THE OUTPUT SHAFT, SERVES IN CERTAIN PHASES OF OPERATION OF THE POWER PLANT TO DELIVER POWER FROM THE POWER TURBINE TO THE OUTPUT SHAFT, AND IN OTHER PHASES OF OPERATION FROM THE OUTPUT SHAFT TO THE COMPRESSOR. A TWO-SPEED GEAR SECTION MAY BE EMPLOYED BETWEEN ONE HYDRAULIC COMPONENT AND THE OUTPUT SHAFT TO INCREASE THE EFFECTIVITY OF POWER TRANSFER AT CERTAIN SPEEDS. CONTROL MEANS SERVES DURING ACCELERATION OF THE POWER PLANT TO ACTUATE PARTS OF THE CLUTCH MEANS AT A CERTAIN PERCENTAGE OF THE MAXIMUM SPEED OF THE OUTPUT SHAFT TO RENDER CERTAIN POWER TRANSFER PATHS EFFECTIVE, AND OTHER PARTS OF THE CLUTCH MEANS AT A DIFFERENT PERCENTAGE OF THE MAXIMUM OUTPUT SHAFT SPEED DURING DECELERATION OF THE POWER PLANT TO RENDER THE OTHER POWER TRANSFER PATHS EFFECTIVE.

Electrohydraulic ram velocity control circuit

Abstract: An electrohydraulic control circuit for controlling the velocity of a ram driving a fluid into a die cavity is disclosed. In accordance with the control method disclosed, the position of the ram is sensed by a pulse generator and sensed ram positions are used to provide electric signals which vary in accordance with the sensed positions and flow of hydraulic ram drive fluid is varied in accordance with the electric signals provided to vary the velocity of the ram. The electric signals may be further varied in accordance with one or more of the positions of a metering member in a hydraulic valve supplying ram drive fluid, the pressure of the fluid in the shot cylinder, the velocity of the ram and the pressure in the die cavity. Control of the ram may be directly from a large electrohydraulic servo valve or a pilot electrohydraulic servo valve may be used to control a larger hydraulic valve supplying ram drive fluid.

Electro-hydraulically controlled perforator

Abstract: A plurality of explosive charges are positioned in an instrument to be lowered into a well. An electrical detonation system is connected to each explosive charge. A hydraulic system controls switches in the electrical system.

Hydraulic circuit of hydraulically driven vehicle

Abstract: A hydraulic pump driven by an engine and a hydraulic motor to drive running wheels are connected with each other by a conduit to form a closed circuit for the circulation of hydraulic oil therethrough, and the hydraulic oil is supplied into said closed circuit from an oil tank through a hydraulic oil supply circuit including a booster pump and excess oil in said closed circuit is discharged through a hydraulic oil discharge circuit. An auxiliary hydraulic motor having a fan on the drive shaft thereof is provided at one point of either the hydraulic oil supply circuit or the hydraulic oil discharge circuit, so as to be driven by the hydraulic oil passing therethrough. Further, a hydraulic oil cooling radiator is provided in the hydraulic oil discharge circuit in opposed relation to said fan to be cooled by the latter. Therefore, the position of the hydraulic oil cooling radiator can be freely selected and a sufficient cooling capacity can be obtained.

Temperature compensated hydraulic valve

Abstract: A valve of the type which employs a hydraulic piston for amplifying the motion of an actuator, wherein undesirable effects of thermal expansion of the hydraulic fluid are eliminated. The valve includes an elastically expandable chamber coupled through a narrow passageway to the hydraulic cylinder for receiving fluid therefrom at a slow rate to hold the extra volume of hydraulic fluid caused by thermal expansion, and a check valve for allowing fluid to flow quickly from the chamber back to the cylinder. The narrow passageway from the hydraulic cylinder to the expandable chamber is formed by an appreciable clearance between a plunger that is moved by the hydraulic fluid and a plunger cylinder in which it slides.

Method and apparatus of assembling and disassembling hydraulic disc brake calipers

Abstract: A method and apparatus for releasing frozen pistons from a disc brake caliper assembly by removing said assembly from a vehicle, removing the brake pads therefrom and placing it on a work table. The work table has a self-contained hydraulic system and a vacuum line is also provided. A spacer block of predetermined thickness is placed between the opposed pistons, and a pressure line connected to the caliper assembly. A hand pump is used to increase system pressure until all the hydraulic pistons, including any frozen pistons, move out of their bores to engage the spacer block. The hydraulic pressure is then released by a manual valve, and the hydraulic line disconnected so that the spacer block can be removed and the defective pistons removed from the caliper assembly. The defective piston, or pistons, are replaced by operable ones, and the vacuum line used to drawn them into their bores, after which the caliper assembly is prefilled with hydraulic fluid and pressure tested prior to reinstallation in the vehicle.

Self-lifting crane

Abstract: A self-lifting crane adapted to raise or lower itself to different levels of any building or horizontal structural members of the building said crane including a frame having four lower outriggers and four upper outriggers which can be retracted and extended by hydraulic cylinders to selectively support the crane on horizontal structural members of a building and four lift outriggers which can be retracted and extended by hydraulic cylinders to selectively support the crane on horizontal structural members of a building; said lift outriggers being mounted in a support structure which can be moved up or down by hydraulic jacks to raise or lower the crane through the use of four positive displacement pumps; said crane including in its hydraulic system trim valving to supply to any one or more of said hydraulic jacks additional fluid to maintain the level of the crane.

Position control for parallel hydraulic systems on an agricultural implement

Abstract: A flexible rod weeder in which the weeder rods are raised and lowered by rocking the frame about the forward wheels. A plurality of gauge wheels are connected to the rear of the frame through extensible and retractable hydraulic motors so that by extending and retracting the motors, the frame is rocked about the forward wheels. The hydraulic motors are connected in parallel and are provided with an adjustable stop which will prevent the lowering of the weeder rods beyond a predetermined position, but permit the flow of fluid from one motor to another so that the gauge wheels equally share the weight of the rear of the frame.

Hydraulic power supply

Abstract: A common hydraulic power supply for a motor vehicle powersteering system and power brake system. The hydraulic power supply supplies hydraulic fluid from a power-steering pump continuously through a flow control valve to a power-steering system. The power brake system is supplied with hydraulic fluid from an accumulator as required. The accumulator is charged with hydraulic fluid by the power-steering pump. Accumulator charging occurs when the pressure in the accumulator falls below a predetermined value, and is accomplished by the diversion of a portion of the flow from the power steering pump to the power brake system. The diverted fluid passes through a pressure sensing valve, the flow control valve, a check valve, and into the accumulator.

Hydraulic valve control system

Abstract: A variable control mechanism for regulating the length of time and amount of opening of an engine valve during each cycle of operation. The control mechanism includes a closed hydraulic circuit or system including a reciprocal slave cylinder, a reciprocal master cylinder, and control means, which control the allocation of fluid volume within the hydraulic circuit so as to regulate the movement of the slave cylinders. The control means are adjustable so that the amount of regulation can likewise be adjusted.

Hydraulic system including two work circuits

Abstract: 1,242,505. Fluid-pressure servomotor systems. GENERAL SIGNAL CORP. Feb. 24, 1970 [May 7, 1969], No.8869/70. Heading G3P. The hydraulic control system described in Specifications 1,178,201 and 1,223,207 is modified to provide a metered fluid supply to each of two separate work circuits 3, 4 at varying rates up to a limiting value less than the full output of the single pump 1. By-pass valve 12 which proportions the flow between circuits 3, 4 according to their demand, is operated by unbalance in a bridge circuit comprising fixed restrictors 27, 28, a variable restrictor 31 controlled by restrictor 29 in response to changes in the flow-rate in line 9, and variable restrictors 24, 25 operated by movement of manual control valves 7, 8.

Hydraulic motor and pump system

Abstract: The specification disclosed a hydraulic system for driving automobiles in which a separate fluid flow system is provided for the front and rear wheels respectively. Each of the drives for the front wheels and for the rear wheels includes three variable displacement pumps, one for pumping fluid and the other two each acting as a motor for one wheel. Both fluid driving pumps are driven by an internal-combustion engine. The hydraulic pumps and hydraulic motors all have counterbalanced vanes which minimize friction. A ratio control valve for each pump and each motor controls the torque to speed ratio at the vehicle wheels. A pressure equalizing valve equalizes pressure between the front and rear fluid flow systems. A bypass valve automatically shortcircuits the flow of fluid through a flow system when the vehicle''s engine is idling.

Hydraulic powered stair negotiating wheel chair or uneven terrain negotiating vehicle

Abstract: The vehicle comprising an adjustable length chassis, rotary spider arm wheel assemblies, including rotary peripheral minor wheels, a central propulsion means including a power source, a motor, and a pump which through a hydraulic system of flow dividers, check and control valves ''''T'''' and conduits applies a controlled differential action through a hydraulic wheel transmission to the wheel assemblies driving spider arms and rotating the peripheral wheels as required to accomplish a desired maneuver. The vehicle is capable of ascending and descending stairs or negotiating uneven terrain, maneuvering and spinning in place.

Hydraulic system for controlling bulldozer blade

Abstract: A single lever control valve means for controlling hydraulic actuators to pitch and tilt a bulldozer blade.

Motor operated servo pump

Abstract: A power actuator in a hydraulic system is controlled in accordance with an electronic control signal energizing a variable displacement servo pump interconnected to the power actuator. In the hydraulic system, the variable displacement servo pump includes a swash plate directly coupled to and positioned by an electric motor. A transducer responds to the position of the swash plate and generates a feedback signal to balance out the effect of the electronic control signal. A pressurized reservoir supplies a base pressure to the hydraulic system when the swash plate of the variable displacement servo pump is in a neutral or null position. This reservoir is protected against an over pressure by a check valve. To compensate for unequal chamber volumes in the power actuator, a shuttle valve diverts excess fluid from the larger volume chamber to the reservoir.

Hydraulic power tool

Abstract: A hydraulically driven radial inflow turbine having power takeoff means attached thereto is actuated and controlled by an axially translatable nozzle ring. A manually actuatable trigger mechanism admits a small amount of control fluid which is tapped from a primary source of liquid under pressure into a chamber defined by the nozzle ring and the turbine housing to move the nozzle ring in registering alignment with the primary liquid inlet apertures to the turbine impeller blades. The trigger assembly proportionately supplies hydraulic pressure to the turbine to control the flow of fluid to the turbine thereby controlling the power output.

Hydraulic power brake booster motor

Abstract: A hydraulic booster motor adapted to be connected to and to activate a vehicle''s master cylinder which is connected to a hydraulic braking system, the booster''s valve body defines two coaxial bores, the large bore carries a power piston which is slidable in it and powertransmittingly connected to the primary piston of the master cylinder, and the small bore carries a reaction piston which is slidable in it and powertransmittingly connected through a linkage to the brake pedal of the vehicle, the booster valve body, together with the two pistons it carries, define a variable volume into which fluid flow is forced through an inlet port and which leaves the variable volume through an exhaust passage which is restricted when driver pushes the brake pedal with his foot.

History of Water-Hammer

Abstract: Water-hammer is the phenomenon of the transmission of pressure and velocity surges along a pipe or conduit when a change in either the velocity or the pressure is imposed at some section in the pipe or at its ends. This change maybe imposed by some mechanical device such as a valve or by a variation in the performance of some hydraulic machinery attached to the pipe, such as a pump or hydraulic turbine. This report traces the theoretical development of the phenomenon of water-hammer from the days of the natural scientists of the seventeenth century to the middle of the twentieth century. In the larger field of hydraulics, early development was based on problems of transportation of water, and on the measurement of flow for irrigation and for domestic use in the centres of population. This involved devices for pumping, for delivery along canals and conduits, and for the measurement of quantities used by individuals. The theory and designs had to do with hydrostatic pressures, friction losses, and discharge coefficients, most of which could be handled by experimental studies. There was no need to consider cases of unsteady flow, either in open channels or in closed pipes and conduits. The action of waves on shore lines, in bays and ports, and along canals, was the only problem similar to water-hammer known in early times, and the mathematical and physical knowledge in those days was unable to cope with this problem except by construction of breakwaters for protection of harbours and shipping. This branch of hydraulics, now designated as coastal engineering, which deals with tidal and surface waves, has become a very important field, particularly in this 20th century.

Hydraulic power circuit with emergency lowering provisions

Abstract: HYDRAULIC POWER CIRCUIT INCLUDING A LIFT CYLINDER FOR RAISING A LOAD, AND A DIRECTIONAL CONTROL VALVE FOR THE CYLINDER WHICH IS ACTUATED BY A LOW PRESSURE REMOTE CONTROL SYSTEM. THE REMOTE CONTROL SYSTEM NORMALLY RECEIVES MOTIVE FLUID FROM A PUMP, BUT, WHEN THE PUMP IS DISABLED OR IDLE, THE CONTROLS MAY BE ADJUSTED TO EFFECT LOWERING OF AN ELEVATED LOAD UTILIZING THE FLUID UNDER LOAD PRESSURE IN THE CYLINDER. FOR THIS PURPOSE, THE CIRCUIT INCLUDES A SWITCH VALVE WHICH ALTERNATELY CONNECTS THE INLET CONDUIT OF THE REMOTE CONTROL SYSTEM WITH THE PUMP OR THE CYLINDER DEPENDING UPON WHETHER PUMP OUTPUT PRESSURE IS ABOVE OR BELOW A PREDETERMINED VALUE, AND A PRESSURE REGULATOR FOR REDUCING THE PRESSURE OF THE FLUID DELIVERED TO THE REMOTE CONTROL SYSTEM FROM THE CYLINDER. IN APPLICTIONS WHERE THE POWER PUMP FOR THE CYLINDER SERVES ALSO AS THE NORMAL SOURCE OF MOTIVE FLUID FOR THE REMOTE CONTROL SYSTEM, THE PRESSURE REGULATOR MAY BE ARRNAGED BETWEEN THE SWITCH VALVE AND THE REMOTE CONTROL SYSTEM SO THAT IT CAN SERVE TO REDUCE THE PRESSURE OF THE FLUID SUPPLIED TO THAT SYSTEM FROM EITHER THE POWER PUMP OR THE LIFT CYLINDER.