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Condition responsive control of motive fluid flow

Subclass of:

060 - Power plants

060325000 - PRESSURE FLUID SOURCE AND MOTOR

Patent class list (only not empty are listed)

Deeper subclasses:

Class / Patent application numberDescriptionNumber of patent applications / Date published
060468000 Of by-pass of motor, pump or flow control element 12
060462000 With externally operable multiwasy valve means directing flow to a stroke device 8
060464000 Of motive fluid transfer between a reservoir and a recirculating path of a pump motor loop 8
060466000 Of braking or holding valve in motor discharge line 3
20120285158PRESSURE LIMITING IN HYDRAULIC SYSTEMS - This disclosure provides for pressure limiting a hydraulic system to a desired pressure value by a particular circuit by controlling and closing the compensator when the desired pressure setting is achieved. Closing the compensator will reduced the pressure head and flow in the circuit resulting in improved efficiency. One illustrated embodiment of the disclosure provides a relief valve in the pilot signal for a compensator. The method relates to limiting the pressure on an open side of the compensator, such that the pressure on the other side closes the compensator thereby limiting the pressure and also flow in the hydraulic circuit. In other words, the pressure on the open side is limited by the relief valve. Thus, the pressure on the other side increases thereby regulating the flow and pressure through the compensator.11-15-2012
20100263364BRAKING CONTROL APPARATUS FOR SLEWING TYPE WORKING MACHINE - Provided is a braking control apparatus for a slewing type working machine capable of giving a braking operation easily intuitively grasped. This apparatus includes: a flow control valve actuator increasing an opening of a flow control valve between a slewing hydraulic motor and a hydraulic pump according to an operation amount of a slewing operation member; pressure control valves limiting respective maximums of an inlet and outlet pressures of the hydraulic motor to a set value corresponding to a pressure command signal to be input; a motor-side pressure controller which retains a set pressure of the motor inlet sided pressure control valve to a pressure for motor driving and lets a set pressure of the motor outlet side pressure control valve be a set pressure for a braking torque corresponding to an operation amount of a braking operation member other than the slewing operation member; and a valve opening limiter reducing the opening of the flow control valve in correspondence with the operation of the braking operation member.10-21-2010
20090145123HYDRAULIC CIRCUIT HAVING HOLDING VALVE OF EXTERNAL PILOT PRESSURE OPERATION TYPE - A hydraulic circuit having a holding valve of an external pilot pressure operation type is provided, which can make a double check valve, which is installed to prevent an actuator from being pushed due to leakage of hydraulic fluid of a main control valve, be opened by an external signal pressure being supplied to shift the main control valve. The hydraulic circuit includes a hydraulic pump connected to an engine and a pilot pump, a hydraulic cylinder connected to the hydraulic pump to expand and contract when hydraulic fluid is supplied thereto, a main control valve installed in a flow path between the hydraulic pump and the hydraulic cylinder and shifted to control a start, a stop, and a direction change of the hydraulic cylinder, a joystick outputting a pilot signal pressure from the pilot pump in accordance with an amount of user's manipulation thereof, a double check valve installed in a flow path between the main control valve and the hydraulic cylinder to be opened by the pilot signal pressure for shifting the main control valve, and preventing the hydraulic cylinder from being moved due to leakage of hydraulic fluid of the main control valve, and a select valve shifted to open the double check valve in response to the pilot signal pressure being supplied in accordance with the manipulation of the joystick.06-11-2009
060460000 Holding or braking valve in motor exhaust line controlled by pressure in motorfeed line 1
20110283692LIQUID PRESSURE MOTOR - A hydraulic motor 11-24-2011
060461000 Discharge from contracting cylinder of double-acting motor controlled 1
20110283693Regenerative Hydraulic Circuit For Dump Truck Bin Lift Cylinder - An articulated dump truck is provided with an electro-hydraulic bin control system including a proportional control valve for the bin lift cylinders and including a solenoid-operated regenerative valve assembly mounted adjacent the lift cylinders and being actuated, during lifting the bin for dumping a load of material from the bin, to cause a regenerative flow to occur when the force required by the bin lift cylinders to continue lifting the bin falls to a predetermined force. The force required for tilting the bin is continuously calculated by an electronic control unit taking into account a sensed bin load, a sensed bin tip amount and a sensed side-to-side inclination of the bin. In a simplified second embodiment, the proportional control valve controls the regenerative flow11-24-2011
Entries
DocumentTitleDate
20100154404HYDRAULIC SYSTEM - A hydraulic system includes an engine driven adjustable hydraulic pump which supplies fluid to a hydraulic consumer, and an electronic control unit. The adjustable pump includes flow controller for controlling a pressure difference between the consumer and the adjustable pump to a pre-determined control pressure difference. The flow controller includes an actuator controlled by the control unit, through which the pressure difference can be controlled. The electronic control unit receives an engine speed signal and controls the actuator to control the pressure difference, in order to make power delivery of the adjustable pump conform to the operating conditions of a vehicle.06-24-2010
20080256943Hydraulic control device - A hydraulic control device includes an oil pan; an oil pump; a strainer; a pressure regulating valve; an oil cooler; a cooler bypass valve with an input port that is connected with a cooler supply oil passage through which the hydraulic oil to be supplied to the oil cooler flows, wherein the input port is communicatively connected with an output port when the hydraulic pressure of the hydraulic oil within the cooler supply oil passage is equal to or greater than a predetermined valve opening pressure; and a cooler bypass oil passage that connects the output port of the cooler bypass valve with an intake oil passage between the strainer and the intake port of the oil pump.10-23-2008
20090308067Hydraulic Drive - The present invention relates to a hydraulic drive which comprises a hydraulic motor having a first hydraulic connector and a second hydraulic connector, wherein the pressure applied at the first hydraulic connector of the hydraulic motor and the pressure applied at the second hydraulic connector of the hydraulic motor are each separately adjustable.12-17-2009
20130086899HYDRAULIC SYSTEM WITH BI-DIRECTIONAL REGENERATION - A hydraulic actuator system including an actuator and a valve assembly configured for bi-directional regeneration. The actuator may include a hollow body and a rod disposed within and extending outwardly from the hollow body. The rod may include a first chamber within the rod and a piston disposed at one end of the rod, defining a second chamber and a third chamber within the hollow body. A valve assembly may be in fluid communication with a first conduit, a second conduit, the first chamber, the second chamber, and the third chamber, wherein the valve assembly is configured to selectively couple one of the first conduit and the second conduit to one or more of the first port, the second port, and the third port, wherein one of the first conduit and the second conduit is configured as a pressure source.04-11-2013
20130055705HYDRAULIC DRIVE SYSTEM FOR CONSTRUCTION MACHINE - A hydraulic drive system for a construction machine has a travel detection device which detects whether or not the operation mode is a traveling operation and a setting changing device. The setting changing device sets the target differential pressure of load sensing control at an absolute pressure Pa when the operation mode is not a traveling operation, and sets the target differential pressure of the load sensing control at an absolute pressure Pa′ rather than the absolute pressure Pa. In this way, in the actuator operation other than traveling, a necessary actuator speed can be obtained and supplied with the necessary maximum flow rate. In addition, during the combined operation, a flow rate in accordance with the opening area ratios of flow control valves can be distributed to actuators different in load pressure from one another; and energy efficiency is enhanced due to less energy loss during traveling operation.03-07-2013
20100083651Circuit for controlling a double-action hydraulic drive cylinder - Circuit for controlling a double-action hydraulic drive cylinder includes a directional control valve having working ports A and B, a pump port P, and a tank port T, wherein the directional control valve has a neutral position in which pump port P is blocked and working ports A, B are connected to tank port T. A pressure-limiting valve and a controllable load-holding valve are connected to the piston space in parallel, and a regeneration check valve is connected in series between a connection point for the parallel components and the rod space. A first precharge valve is connected between the working port A and the connection point, and a first bypass check valve is connected anti-parallel parallel with the first precharge valve and the load-holding valve. A second precharge valve is connected in series with the directional control valve between the tank port P and the rod space.04-08-2010
20090235658INERTIAL BODY DRIVE SYSTEM - A pressure selector valve (09-24-2009
20090249776LOCK VALVE WITH GROOVED PORTING IN BORE - A lock valve includes a lock valve body having a bore with a valve spool reciprocatingly received therein. There is a check valve adjacent each end of the bore. Each of the check valves has a check valve member facing the bore and resiliently biased towards a valve seat at each end of the bore. A pressure relief port communicates with the bore near the center thereof and between lands of the valve spool. A pair of spaced-apart grooves are disposed within the spool valve bore. Each groove permits fluid communication past a land of the valve spool when the valve spool is displaced towards one end of the bore by fluid pressure applied to other end of the bore so as to unseat the check valve member adjacent to the one end to the bore and allow pressurized fluid to pass from the one end of the bore, through the groove, and into the relief port.10-08-2009
20080295508Force feedback poppet valve having an integrated pressure compensator - The force feedback poppet valve includes a valve body having a main chamber, a first port, and a second port. The force feedback poppet valve further includes a main poppet disposed within the main chamber and movable between an open position and a closed position to control fluid flow between the first port and the second port. The main poppet forms a control chamber within the main chamber. The force feedback poppet valve further includes a first passage communicating the control chamber with the second port, a second passage communicating the control chamber with the first port, and a pilot valve having a pilot poppet for controlling fluid flow between the control chamber and the first port through the second passage. The force feedback poppet valve further includes a pressure compensator disposed within the main poppet, and fluidly connected to the second port via the first passage. The force feedback poppet valve further includes a first spring coupled between the main poppet and the pilot poppet to provide a force proportional to a distance between the main poppet and the pilot poppet, and a second spring coupled between the pressure compensator and the pilot poppet to provide a force proportional to a distance between the pressure compensator and the pilot poppet.12-04-2008
20120060486HYDRAULIC CONTROL DEVICE, CONTROL METHOD OF THEREOF, AND AUTOMATIC TRANSMISSION - A hydraulic control circuit includes an oil pump for generating a hydraulic pressure by being rotated by power of a driving force source, a line pressure oil passage in which at least a line pressure generated by adjusting the hydraulic pressure generated by the oil pump is supplied, a driving force source stopping unit that stops the rotation of the driving force source, and a hydraulic pressure reduction suppressing unit that is provided in the line pressure oil passage and suppresses a reduction of the line pressure accompanying reverse rotation of the driving force source when the rotation of the driving force source is stopped by the driving force source stopping unit.03-15-2012
20120011842HYDRAULIC TRANSMISSION CONTROL - A hydraulic transmission unit comprises at least one pressure regulation valve (01-19-2012
20100170239HYBRID WORKING MACHINE - In a hybrid working machine in which the maximum engine output is set at the average power and the maximum pump input is set to be larger than the maximum engine output in a normal state, in an abnormal state in which the level of charge of a battery decreases and assistance ability of a motor function of a power machine is lost, the minimum pump flow rate is reduced to a value equal to or smaller than a standby flow rate, the standby flow rate being the minimum pump flow rate used in normal state control, and a set value of the maximum pump input is changed such that the maximum pump input is smaller than the maximum engine output.07-08-2010
20100170238SYSTEM AND METHOD FOR THE TEMPERATURE REGULATION OF A HYDRAULIC FLUID - The present invention provides a device and a method for regulating a temperature (T) of hydraulic fluid in at least one hydraulic circuit (07-08-2010
20090151347Operation Control Circuit for Construction Machine - The operation control circuit of the present invention reduces the speed of an actuator, such as a rotation motor, according to reduction in the rotational speed of an engine. When the engine rotational speed is at its maximum, a pilot pressure in a pilot conduit is set to a relief pressure of a relief valve. When the engine rotational speed is reduced, the flow rate of pilot pressure hydraulic fluid decreases, and the pressure difference over a throttle section becomes smaller than the relief pressure, so that the pilot pressure is set to the pressure difference. Even if the operator operates an operation lever to a full stroke position the spool valve does not go to the fully opened state, since the pressure is low. As a result, the flow rate of hydraulic fluid supplied to the rotation motor is reduced, so that the speed of rotation is reduced.06-18-2009
20090282825Actuator Control Device - In an actuator control device that controls an expansion/contraction operation of a hydraulic cylinder, when a main spool 11-19-2009
20130118160METHOD AND DEVICE FOR CONTROLLING POWER OUTPUT OF ENGINE FOR WORKING MACHINE - An engine control device detects the state of work of a working vehicle such as a construction machine or the like, and controls the power output capacity of an engine automatically. A determination is made as to whether excavation or uphill traveling is being performed, based upon the detection signals from a hydraulic oil pressure detector for a hydraulic cylinder of an arm, detectors for arm and bucket operation commands, a shift operation detector for a transmission, a pitch angle detector for the vehicle body, a traveling acceleration detector, and an accelerator opening degree detector. When the result of this determination is that excavation or uphill traveling is being performed, the engine is controlled to operate at a high power capacity, while at other times it is controlled to operate at a low power output capacity.05-16-2013
20100263363HYDRAULIC CONTROL DEVICE AND PRESSURE SWITCH - In a hydraulic control device H comprising a pressure source P which can be switched on and switched off, a reservoir R and a pressure switch W located in a discharge path 10-21-2010
20120067039INDUSTRIAL MACHINE - A three-dimensional measuring machine (industrial machine) includes an air supplier supplying air; a drive mechanism driven by the air supplied from the air supplier; an electromagnetic valve provided inside an air regulator set to open and close an air supply passage inside the air regulator set, the air regulator set introducing the air from the air supplier to the drive mechanism; and a motion controller controlling the electromagnetic valve to block the air supply passage when a time since the drive mechanism stopped operation reaches a preset time.03-22-2012
20110225963ACTUATOR FOR GAS-OPERATED EMERGENCY OPENING OF AN OPENABLE ELEMENT OF AN AIRCRAFT, HAVING MEANS FOR VENTING THE GAS - Actuator for emergency opening of an openable element (Co) of an aircraft, having: 09-22-2011
20090188250Motor Vehicle Control Device for Regulating the Pressure of the Volumetric Flow of a Motor Vehicle Hydraulic Apparatus and Associated Pressure Regulation Method - A motor vehicle control device with a digital control loop has an actuator of an electrical actuator device in order to regulate the pressure of the volumetric flow of a motor vehicle hydraulic apparatus. A current limiting unit is provided in the forward path of the digital control loop between the digital controller of the latter and the actuator of the electrical actuator device. The current limiting unit, in order to protect the components of the electrical actuator device, limits the manipulated variable signal from the digital control loop if a predefined permissible current threshold value is exceeded in the electrical actuator device. The digital controller has an additional limiting unit which essentially limits the I component of its manipulated variable signal from the time at which the current limiting unit is activated.07-30-2009
20100263362METHOD FOR CONTROLLING A WORKING MACHINE - A method for controlling a working machine including a hydraulic system for controlling a plurality of work functions, including lift and tilt of an implement, includes the steps of determining a maximum pressure of a hydraulic fluid for performing a certain task with the implement individually for at least one of the work functions, and delivering the hydraulic fluid, pressurized at most to the determined maximum pressure, to the work function.10-21-2010
20130213030Hydrostatic Drive System - A hydrostatic drive system includes a user in the form of a differential cylinder connected in a closed circuit to a high-pressure pump. A piston-side compression chamber and a piston-rod-side compression chamber of the differential cylinder are in communication with the high-pressure pump. The closed circuit includes a protection device having first and second protection valve devices that each includes a pressure relief valve and an anti-cavitation valve. The pressure relief valve of the first protection valve device is provided with an override device, by means of which the opening pressure of the pressure relief valve can be varied. When the high-pressure pump delivers into the piston-rod-side compression chamber, the pressure relief valve of the first protection valve device is adjusted by means of the override device to a reduced opening pressure and the differential volumetric flow flows out via the pressure relief valve to a low-pressure system.08-22-2013
20100236234HYDRAULIC VALVE DEVICE - A Hydraulic valve device includes a first engine port and a second engine port to a double acting hydraulic motor, and a pump, a hand valve, which is arranged such that it connects the engine ports to the tank and the pump, and which hand valve has two open positions, wherein the pump in the first open position via a line is connected to the first engine port and the tank via a line is connected to the second engine port, and wherein the pump in the second open position via the line is connected to the second engine port and the tank via the line is connected to the first engine port, and a first nonreturn valve, arranged between the pump and the second engine port and opens towards the second engine port. A piston which by way of the load pressure in the first engine port via a line governs the first nonreturn valve, such that it is kept closed as long as the pump pressure does not exceed the load pressure, and a second nonreturn valve arranged such that it, as long as the hand valve is in its first open position, connects the first engine port to the second engine port and opens in direction towards the second engine port.09-23-2010
20100101223FLOW COMPENSATED RESTRICTIVE ORIFICE FOR OVERRUNNING LOAD PROTECTION - A hydraulic circuit for an actuator that has a piston and piston rod that will move a load in a first direction, and which can be externally loaded in an opposite direction, includes a flow compensated valve between the actuator and a control valve. When the piston in the actuator is moved in the second opposite direction under the external load and the rate of flow of fluid out of the actuator through the flow compensated valve exceeds a selected rate, an orifice is introduced in the flow path to restrict flow from the actuator.04-29-2010
20100218494Pump Control Apparatus for Hydraulic Work Machine, Pump Control Method and Construction Machine - A pump control apparatus for a hydraulic work machine includes: a rotation speed setting device that sets a target rotation speed for an engine; a rotation speed control device that controls an engine rotation speed so as to adjust the engine rotation speed to the target rotation speed; a first variable hydraulic pump used to drive a work hydraulic actuator, driven by the engine; a second variable hydraulic pump used to drive a cooling fan, driven by the engine; and a pump control device that controls an output flow rate of the first variable hydraulic pump and an output flow rate of the second variable hydraulic pump so as to ensure that a sum of an intake torque of the first variable hydraulic pump and an intake torque of the second variable hydraulic pump does not exceed an engine output torque determined in advance based upon the target rotation speed. The pump control device a) controls the output flow rate of the second variable hydraulic pump based upon the target rotation speed and a target output flow rate of the second variable hydraulic pump assuring a required cooling air volume at the cooling fan; and b) regulates the intake torque of the first variable hydraulic pump by calculating the intake torque of the second variable hydraulic pump and subtracting the intake torque of the second variable hydraulic pump from the engine output torque determined in advance based upon the target rotation speed.09-02-2010
20090071145FLOW CONTROL APPARATUS FOR HEAVY CONSTRUCTION EQUIPMENT - A flow control apparatus for heavy construction equipment is provided, which can prevent overspeed and abrupt operations of an actuator due to an excessive flow rate during an initial operation of the actuator when a composite work is performed by simultaneously operating an option device and another actuator, and can prevent the cut-off of hydraulic fluid supply to the option device due to an operation inability of a flow control valve when leakage of the hydraulic fluid occurs due to the increase of the temperature of the hydraulic fluid. The flow control apparatus includes a hydraulic pump, an actuator for option devices, a variable control spool installed to be shifted by pilot signal pressure, a switching valve installed to be shifted by a difference between pressure in an inlet-side path and pressure in an outlet-side path of the variable control spool, a logic poppet installed to open/close a high-pressure path of the hydraulic pump, a groove formed on a sliding surface of the logic poppet, and a flow path for connecting the groove to an outlet-side path of the logic poppet. If leakage of hydraulic fluid through a gap formed on the sliding surface of the logic poppet occurs, mutual connection between the outlet-side path and a back chamber of the logic poppet is intercepted by the groove and the flow path.03-19-2009
20120031089Axial Bearing For Use In A Hydraulic Device, A Hydraulic Transformer And A Vehicle With A Hydraulic Drive System - An axial bearing between a first part and a second part that presses with an axial load against the first part and can rotate around a rotation axis relative to the first part comprising a circular or arc-shaped ridge on the first part centered around the rotation axis, a pressure source for providing pressurized hydraulic fluid on a first side of the circular or arc-shaped ridge, an adjustable gap between the circular or arc shaped ridge and a bearing surface on the second part, wherein the pressurized hydraulic fluid flows through the adjustable gap to a second side of the circular or arc-shaped ridge. In accordance with the invention the circular or arc-shaped ridge or the bearing surface include a ridge chamber for locally creating a larger adjustable gap between the circular or arc-shaped ridge and the bearing surface.02-09-2012
20090107136ELECTROHYDRAULIC TRANSMISSION CONTROLLER, TRANSMISSION DEVICE, AND A MOTOR VEHICLE DRIVE TRAIN - An electrohydraulic transmission controller (04-30-2009
20110154815SWING MOTOR CONTROL METHOD IN OPEN CENTER TYPE HYDRAULIC SYSTEM FOR EXCAVATOR - A swing motor control method in an open center type hydraulic system for a hydraulic excavator is provided, which can adjust the speed of a swing motor so that a swing device and a working device harmonize with each other according to a discharge pressure of a hydraulic pump during a multifunctional work of the working device and the swing device. The swing motor control method in an open center type hydraulic system for an excavator including first and second hydraulic pumps, a swing motor, a working device actuator including a boom or arm actuator, a working device control valve controlling a start, a stop, and a direction change of the working device actuator, a discharge pressure sensor sensing the discharge pressure of the second hydraulic pump, and a swing motor controller controlling a speed of the swing motor in accordance with the pressure detected by the discharge pressure sensor, includes controlling the speed of the swing motor during a multifunctional operation of the swing device and the working device, comparing the pressure detected by the hydraulic pump discharge pressure sensor with a preset pump discharge pressure, and controlling a limiting speed of the swing motor in accordance with the result of comparison.06-30-2011
20120198832Hydraulic System for a Work Vehicle - A hydraulic system for a work vehicle is disclosed. A preferential flow-dividing valve supplies a fixed amount of oil discharged from a variable displacement pump preferentially to a preferential hydraulic oil section and a surplus oil flow from the pump to a non-preferential hydraulic oil section. A plurality of electromagnetic proportional control valves are provided in the non-preferential hydraulic oil section for controlling oil flows relative to a plurality of hydraulically operated devices provided in the non-preferential hydraulic oil section. A necessary flow rate calculating module calculates a necessary oil flow rate in each of the preferential hydraulic oil section and the non-preferential hydraulic oil section based on a preferential oil flow rate of the preferential flow-dividing valve supplied to the preferential hydraulic oil section and an amount of current distributed to each of the plurality of electromagnetic proportional control valves in the non-preferential hydraulic oil section.08-09-2012
20120144818POWER TRANSMISSION DEVICE - A power transmission device that transmits power from a motor to a wheel via a hydraulically driven friction engagement element and that includes a mechanical pump driven by the motor to produce a hydraulic pressure that is regulated by a pressure regulating valve; an electric pump that produces a hydraulic pressure; a switching mechanism that either switches an output pressure of the regulating valve or an output pressure of the electric pump to a servo of the engagement element based upon a signal pressure, and a drain valve that opens to drain oil when a hydraulic pressure of a preset pressure or more is applied, and the switching mechanism connects to the drain valve to allow communication between the electric pump and the drain valve in the first state, and shut off communication between the electric pump and the drain valve.06-14-2012
20100281859OIL PRESSURE SYSTEM AND VALVE ASSEMBLY USED IN OIL PRESSURE SYSTEM - In the oil pressure system, a control unit sets a flow passage changeover valve to be in a merging state, and sets a relief pressure to a low relief pressure via a relief pressure changeover unit in the case that the rotational speed of the engine is lower than a predetermined threshold level. Also, the control unit sets the flow passage changeover valve to be in a branching state, and sets the relief pressure to a high relief pressure via the relief pressure changeover unit in the case that the rotational speed of the engine is the predetermined threshold level or higher.11-11-2010
20100186404CONTROL DEVICE FOR INDUSTRIAL VEHICLE - A control device for an industrial vehicle including an electric storage device, a load device, a hydraulic pump, and a load motor is disclosed. The electric storage device stores regenerative power generated through regenerative braking performed by the travel motor. The hydraulic pump supplies a hydraulic circuit with hydraulic oil to operate the load device. The load motor drives the hydraulic pump. The control device includes a power control unit and a resistance flow passage. The power control unit executes control for supplying the load motor with the regenerative power when the electric storage device is in a fully charged state during regenerative braking performed by the travel motor. The resistance flow passage is arranged in the hydraulic circuit and enables passage of hydraulic oil while applying flow resistance to the hydraulic oil. When the electric storage device is in the fully charged state during regenerative braking performed by the travel motor and, at the same time, the load device is not performing a load handling operation, the hydraulic oil supplied from the hydraulic pump is guided to the resistance flow passage.07-29-2010
20090301075Control Apparatus for Work Machine - A speed of a hydraulic actuator is matched with that of an electric actuator when the hydraulic actuator and the electric actuator are concurrently actuated. When determination units (12-10-2009
20090293470Over-Loading Prevention Device of Construction Machinery - In an over-loading prevention device including a hydraulic pump, a control valve, and a control lever, a discharge-quantity control unit performs constant-torque control which decreases a discharge quantity in proportion to an increase in a discharge pressure in the pump to control an input torque of the pump uniformly. An operation-state detection unit detects an actuation state of the control lever. A control unit outputs a control signal that sets the pump input torque to a minimum torque according to the constant-torque control, to the discharge-quantity control unit when the control lever is operated over a predetermined speed, and subsequently changes a level of the control signal to a maximum torque according to the constant-torque control in accordance with a predetermined control pattern to raise the pump input torque.12-03-2009
20100031650CONSTRUCTION MACHINE AND METHOD OF CONTROLLING CONSTRUCTION MACHINE - The present invention provides a construction machine where overheating of mounted electric devices can be prevented properly with a simple structure and a method of controlling the construction machine. For this purpose, a pump target discharge flow rate of a hydraulic pump is calculated based on an operated amount of an operating unit, a temperature of an electric device mounted on the construction machine is detected, an engine minimum speed, which is a minimum possible speed of an engine in carrying out low-speed matching for matching output of the engine and pump absorbing horsepower of the hydraulic pump to each other in a low-speed region where speed of the engine is lower than set speed, is calculated by using the detected temperature of the electric device, and a maximum value out of a corresponding speed of the pump target discharge flow rate and the engine minimum speed is generated as a candidate for an engine target speed.02-11-2010
20120036845HYDRAULIC CONTROL APPARATUS FOR WORK MACHINE - A hydraulic pump driven by an engine, a hydraulic actuator, and a negative control circuit are provided on an open center hydraulic circuit, for guiding the hydraulic pressure in the center bypass to the hydraulic pump, as a negative control pressure. A negative control pressure control device controls the negative control pressure to an arbitrary value is also provided. The pump characteristic of the hydraulic pump is set such that the discharge flow rate is minimized when the negative control pressure in the negative control circuit is equal to or greater than a first predetermined pressure. Furthermore, an idling detection device that detects whether the hydraulic actuator is in a non-operated state or not is provided. The negative control pressure is forcefully controlled to the first predetermined pressure or higher when the non-operating state is detected.02-16-2012
20110072811ENGINE DRIVEN LIFT GATE POWER SYSTEM - A power system for a lift gate is provided. The power system includes an actuator system including an actuator for a lift gate, and a lift gate engine coupled to the actuator system. The lift gate engine is configured for generating kinetic energy from a fuel source to power the actuator system for operating the lift gate.03-31-2011
20120144819HYBRID WORKING MACHINE - A hybrid working machine includes an engine, an assist motor configured to assist the engine, a hydraulic pump driven by the engine, an electric power accumulating unit configured to feed the assist motor with electric power, an electric-discharge electric motor configured to perform power running with electric power of an electric power accumulator of the electric power accumulating unit, an electric-discharge hydraulic motor connected to the electric-discharge electric motor, and a hydraulic circuit configured to control driving of the electric-discharge hydraulic motor. The hydraulic circuit includes a circulation circuit configured to be connected to a hydraulic feed port and a hydraulic discharge port of the electric-discharge hydraulic motor and a selector valve configured to perform such switching as to connect the electric-discharge hydraulic motor to the circulation circuit at a time of performing an electric discharge operation.06-14-2012
20120304636HYDRAULIC FAN CIRCUIT - A hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan operably connected to and driven by the motor. The circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a pressure limiting valve configured to selectively reduce pressure of a flow of pilot fluid directed to the primary pump. The circuit further includes an override valve configured to selectively connect the supply passage to the pressure limiting valve.12-06-2012
20100319337HYDROSTATIC DRIVE SYSTEM - The invention relates to a hydrostatic drive system having a pump (12-23-2010
20100011757Safety Device for Hydraulic Working Machine - There are provided: control valves 01-21-2010
20120011841HYDRAULIC DEVICE FOR STEPLESS TRANSMISSION - A hydraulic device includes a switch-over valve 01-19-2012
20120151910VARIABLE PRESSURE CONTROL SYSTEM FOR DUAL ACTING ACTUATORS - A variable pressure control system for varying pressures in the fluid circuits of a dual acting actuator over a range of pressures. The variable pressure control system includes a controller that cooperates with pressure regulators for regulating the desired pressure in the fluid circuits.06-21-2012
20120151911COMBINATION OF A CHAMBER AND A PISTON, A PUMP, A MOTOR, A SHOCK ABSORBER AND A TRANSDUCER INCORPORATING THE COMBINATION - A combination of a piston and a chamber, wherein the chamber defines an elongate chamber having a longitudinal axis, the chamber having, at a first longitudinal position thereof, a first cross-sectional area thereof and, at a second longitudinal position thereof, a second cross-sectional area, the second cross-sectional area being 95% or less of the first cross-sectional area, the change in cross-section of the chamber being at least substantially continuous between the first and second longitudinal positions, the piston being adapted to adapt itself to the cross-section of the chamber when moving from the first to the second longitudinal position of the chamber. The piston may comprise an umbrella-like support structure or a fiber enforced deformable container comprising a foam or a fluid. The combination may be used in a pump, a linear actuator, a motor, or a shock absorber.06-21-2012
20100095665Hydrostatic pump and motor with improved torque reversal characteristics - A system and method for variator control employs positively directed electronic make-up and flushing relief valves for more precise torque control of a hydraulic variator, especially during torque reversal, as well as improved cold weather operation. This can improve machine response during periods of severe torque change. The ability to more tightly control variator torque allows more precise torque management algorithms for power control and engine matching purposes. Moreover, the ability to positively control venting of the hydraulic circuit for purposes of fluid cooling allows for more consistent machine response regardless of ambient temperature.04-22-2010
20120131913HYDRAULIC SWING-CONTROLLING APPARATUS OF WORK MACHINE - In a work machine including a hydraulic pump (05-31-2012
20120312007CONTROL SYSTEM FOR HYBRID CONSTRUCTION MACHINE - A control system for construction machine includes a pair of first and second main pumps which are variable-displacement pumps, first and second circuit systems connected to the first and second main pumps and including a plurality of control valves, main switching valves provided between the first and second circuit systems and the first and second main pumps, a hydraulic motor for power generation connected to the first and second main pumps via the main switching valves, a generator coupled to the hydraulic motor for power generation, and a battery for storing power generated by the generator. When at least the main switching valve connected to one circuit system is at a position to cause one main pump connected thereto to communicate with the hydraulic motor for power generation, the main switching valve connected to the other circuit system causes the other main pump to communicate with the other circuit system.12-13-2012
20120073282HYDRAULIC SYSTEM - A hydraulic system, especially in a high-pressure application, comprises a pressurized-fluid tank, a pressurized-fluid pump driven by a drive unit, at least one hydraulic load that can be pressurized thereby and a control and/or distribution unit connected fluidically between the pressurized-fluid pump and the load. This unit is provided with a housing and a core received therein and connected rigidly with the housing, which core bears with part of its surface in the region of a common, closed, especially cylindrical joint face with the housing on a corresponding inside face of a housing opening. Surface groove-like flow ducts are provided on the core and/or the housing in the region of the joint face, and the pressurized-fluid pump is directly built onto the control and/or distribution unit in the region of a free end face of the core.03-29-2012
20080302099Method for Controlling a Hydraulic Cylinder and Control System for a Work Machine - A method is provided for controlling a hydraulic cylinder, including detecting at least one operating parameter, and variably controlling a communication path between the piston-rod side and piston side of the hydraulic cylinder on the basis of the detected operating parameter.12-11-2008
20110225962Variable Speed Hydraulic Pump Apparatus and Method - An embodiment in accordance with the present invention provides a hydraulic pump including a first motor running at a fixed speed, a reservoir for fluid and a first pump operatively coupled to the motor such that the pump runs at the same speed as the motor and generates a flow of fluid from the reservoir. The hydraulic pump further includes a second motor, a speed control valve operatively coupled to the to the first pump and operatively coupled to the second motor such that a portion of the flow is directed to the second motor and the remainder of the flow is diverted to the reservoir, and a second pump operatively coupled to the second motor such that the second pump is driven by the second motor.09-22-2011
20120279211PUMP CONTROL OPERATING SYSTEM OF CONSTRUCTION MACHINE - The present disclosure is a construction machine, such as an excavator, which comprises a plurality of hydraulically driven actuators, in which some of the actuators are provided in a one-to-one pump system where hydraulic pumps are connected to the respective actuators such that a working fluid is supplied from the respective pumps, and the remaining actuators are provided in an auxiliary control valve system where the working fluid is distributed by an auxiliary control valve connected to one or more pumps. When an amount of the working fluid of an actuator associated with the auxiliary control valve is insufficient, the actuator associated with the auxiliary control valve is connected to a pump of the one-to-one pump system to share the pump of the one-to-one pump system.11-08-2012
20110146261SYSTEM AND METHOD FOR CONTROLLING AN ELECTRO-HYDRAULIC CHARGING SYSTEM - The disclosure describes, in one aspect, a control system for charging an electro-hydraulic charging system. The control system including at least one sensor operatively coupled to an engine for sensing at least one engine parameter indicative of an operating status of the engine and a controller adapted to charge the charging system when the operating status of the engine is determined to be stable.06-23-2011
20110146260HYDRAULIC SYSTEM HAVING A HYDROSTATIC, VALVE-CONTROLLED PISTON ENGINE - The invention relates to a hydraulic system, having a hydrostatic, valve-controlled piston engine with a plurality of valves actuatable by an actuator as a function of the motion of the pistons, and with a control unit for triggering the actuators, which is arranged for generating an electrical attraction current in a first time segment and a maintenance current in a second time segment. The object of the invention is for the valves to switch with quick reactions and function safely, so that the expected functionality and safe operation of the hydrostatic piston engine under various operating conditions is ensured. This is attained in that the control unit includes a current regulating device, which triggers the actuators in current-regulated fashion.06-23-2011
20130167521INDUSTRIAL VEHICLE - A forklift (07-04-2013
20080223030Hydraulic Driving Device for Operating Machine - In a hydraulic driving device for an operating machine, when an output value of an operating device is in a first predetermined range, a pump is stopped and each of an open and closed valve and a hydraulic control valve is closed. When the output value goes beyond the first predetermined range, the pump is started and the open and closed valve is opened. When the output value goes beyond a second range greater than the first predetermined range, the hydraulic control valve is opened to supply a hydraulic fluid to an actuator.09-18-2008
20120247095HYDRAULIC PRESSURE CONTROL DEVICE - A hydraulic pressure control device including a pump driven to generate hydraulic pressure; a first pressure regulation valve that regulates hydraulic pressure in a first passage coupled to a pump along with discharge of oil; a second pressure regulation valve that receives the hydraulic pressure in the first passage and regulates the hydraulic pressure to an engagement pressure to engage a lock-up clutch according to a first signal pressure to output the engagement pressure to a second passage that supplies the oil to an engagement chamber; and a third pressure regulation valve that receives the hydraulic pressure in the first passage or the engagement pressure output to the second passage and regulates the received pressure according to the first signal pressure or a second signal pressure that synchronizes with the first signal pressure to output the resulting pressure to a third passage that supplies the oil to the disengagement chamber.10-04-2012
20130111892MIXER DRUM DRIVING DEVICE - A mixer drum driving device includes a hydraulic motor that rotates a mixer drum, a first hydraulic pump that is driven by an engine to be capable of supplying working oil to the hydraulic motor, an electric motor, a power supply connected to the electric motor, a second hydraulic pump capable of supplying the working oil to the hydraulic motor on the basis of a driving force of the motor, and a flow dividing valve that divides the working oil discharged from the first hydraulic pump and supplies the working oil to the hydraulic motor and the second hydraulic pump. The second hydraulic pump is configured to rotate the electric motor using the working oil. The electric motor is configured to generate electric power so as to charge the power supply when driven to rotate by the second hydraulic pump.05-09-2013
20110047999CONTROL UNIT OF HYDRAULIC BRAKE APPARATUS FOR VEHICLE - A control unit of a hydraulic brake apparatus for a vehicle including a housing, a switching control valve, pressure increase control valves, pressure decrease control valves, a reservoir, a pump driven by a motor, a first passage, a second passage, an inner bore and a passage forming member being liquid-tightly fitted into the inner bore in order to form an extended ring-shaped passage, wherein the extended ring-shaped passage forms a part of the first passage, and the switching control valve, the pressure increase control valves and the outlet valve are connected to the extended ring-shaped passage, and a part of the second passage is formed within the passage forming member, and end portions of the part of the second passage are connected to the switching control valve and the switching valve.03-03-2011
20120255293HYDRAULIC SYSTEM HAVING FIXABLE MULTI-ACTUATOR RELATIONSHIP - A hydraulic system for a mobile machine is disclosed. The hydraulic system may have a first actuator, a first valve arrangement, a second actuator, and a second valve arrangement. The hydraulic system may also have at least one operator interface device movable by an operator to generate a first signal indicative of desired work tool movement in a first manner, and a second signal indicative of desired work tool movement in a second manner; and a controller configured to generate a first flow rate command directed to the first valve arrangement based on the first signal, and generate a second flow rate command directed to the second valve arrangement based on the second signal. The controller may also be configured to selectively generate a third flow rate scaled from the first flow rate command and directed to the second valve arrangement based on only the first signal.10-11-2012
20130098026Hydraulic Fluid Actuated Equipment Leveling Assembly - A hydraulic fluid actuated equipment leveling assembly incorporating a plenum having adjustment ports; an input channel opening the plenum; a disk valve operable for opening and closing the adjustment ports; telescoping and hydraulic ram actuated equipment support pedestals; hydraulic lines spanning between the plenum's adjustment ports, and the pedestal's hydraulic rams; and fluid displacing plungers connected operatively to the hydraulic lines for adjusting the hydraulic line's interior volumes.04-25-2013
20130205766Hydrostatic Transmission - A hydrostatic transmission comprises a hydraulic pump, a hydraulic motor, first and second main fluid passages fluidly connecting the hydraulic pump to the hydraulic motor so as to constitute a closed fluid circuit, a charge fluid passage, a plurality of first charge check valves and a plurality of second charge check valves. The plurality of first charge cheek valves are interposed between the charge fluid passage and the first main fluid passage so as to allow only flow of fluid from the charge fluid passage to the first main fluid passage when the first main fluid passage is hydraulically depressed relative to the charge fluid passage. The plurality of second charge check valves are interposed between the charge fluid passage and the second main fluid passage so as to allow only flow of fluid from the charge fluid passage to the second main fluid passage when the second main fluid passage is hydraulically depressed relative to the charge fluid passage.08-15-2013

Patent applications in class Condition responsive control of motive fluid flow

Patent applications in all subclasses Condition responsive control of motive fluid flow