Class / Patent application number | Description | Number of patent applications / Date published |
060428000 | Having condition responsive control in a system of separately operable power input pumps, pump motors, pump cylinders or pressure fluid sources | 60 |
20080223027 | Hydraulic circuit for construction machine - A hydraulic circuit for a construction machine is disclosed, which can prevent an energy loss of a hydraulic system by automatically reducing revolution of an engine when a working device such as a boom is not driven. The hydraulic circuit includes first to third hydraulic pumps, first to third switching valves for controlling hydraulic fluid fed to working devices, a fourth switching valve for controlling hydraulic fluid fed to left and right traveling devices, a confluence switching valve for selectively supply the hydraulic fluid from the third hydraulic pump to either the working devices on the first hydraulic pump side or the working devices on the second hydraulic pump side, a signal line for traveling devices, signal lines for working devices, and a shuttle valve for selecting any one of the signal pressure formed in the signal line for the traveling devices and the signal pressure formed in the signal lines for the working devices. | 09-18-2008 |
20080276608 | HYDRAULIC DRIVE SYSTEM WITH TEMPERATURE COMPENSATION FOR PRESSURE LIMIT - A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for compensating for temperature changes using varying pressure limits helps to maintain the hydraulic drive system in normal operation, thereby promoting efficiency within the hydraulic drive system. | 11-13-2008 |
20090038305 | Hydraulic system for an automatic transmission - A hydraulic system for an automatic transmission operatively connected to an internal combustion engine that is operable in a start-stop mode. The hydraulic system includes a hydraulic energy source to supply the hydraulic system with hydraulic energy, the hydraulic energy source including at least one electrically driven hydraulic pump to supply the hydraulic system with hydraulic energy during a stopping phase of the internal combustion engine. To achieve a reduction in fuel consumption and CO | 02-12-2009 |
20090071142 | Hydraulic control device for vehicular hydraulic control circuit - In a vehicular hydraulic control circuit equipped with a mechanically-operated oil pump and an electrically-operated oil pump, a hydraulic control device is provided for reducing a high load imposed on the electrically-operated oil pump, when the electrically-operated oil pump is started during stoppage of the mechanically-operated oil pump. When the electrically-operated oil pump ( | 03-19-2009 |
20090151346 | SHOCK ABSORPTION DEVICE AND CONTROL METHOD THEREOF FOR SMALL SWING RADIUS EXCAVATOR - A shock absorption device and a control method thereof for a small swing radius (SSR) excavator are provided, which can relieve shock generated on a boom cylinder by controlling only the discharge flow rate of hydraulic pumps, being supplied to the boom cylinder, even without controlling a main control valve when a boom of the excavator ascends at its maximum height through manipulation of a control level. The shock absorption device for an SSR excavator includes first and second hydraulic pumps, a control lever, a boom cylinder coupled to the first hydraulic pump, a main control valve for controlling a start, a stop, and a direction change of the boom cylinder, a boom-up manipulation amount detection means, a hydraulic pump flow computation means, a boom confluence means for making hydraulic fluid discharged from the first and second hydraulic pumps confluent together, a boom deceleration region detection means for detecting a boom deceleration region, and a flow controller for controlling the discharge flow rate of the first and second hydraulic pumps. | 06-18-2009 |
20090158727 | HYDRAULIC SYSTEM - A hydraulic system for an agricultural vehicle is proposed. The hydraulic system comprises a main hydraulic circuit, which is fed with hydraulic fluid by a main hydraulic pump, a variable displacement charge pump which supplies charge pressure to the main hydraulic pump, and a lubricating hydraulic circuits. In order to keep efficiency losses on the vehicle to a minimum, particularly at high engine speeds, part of the hydraulic fluid delivered by the charge pump can be diverted to the lubricating hydraulic circuit. | 06-25-2009 |
20090199552 | HYDRAULIC WORKING MACHINE - A hydraulic circuit for a hydraulic working machine is composed of a main pump | 08-13-2009 |
20090255247 | Method of controlling a hydraulic actuator - A control method for controlling a hydraulic actuator to impart oscillatory excitation to a load, the actuator comprising at least one hydraulic chamber and a movable member capable of moving in said chamber between two extreme positions under the action of a liquid under pressure, wherein the method comprises the steps consisting in: determining an operating point for said actuator, which operating point corresponds to a rest position of said movable member; applying a hydraulic command to bring said movable member into correspondence with said rest position; and applying a hydraulic command to cause said movable member to perform reciprocating movement about said rest position, said reciprocating movement being adapted to apply a desired excitation to said load; the rest position of said movable member being selected to be significantly off-center relative to said extreme positions. Advantageously, said rest position is selected to be as close as possible to one of said extreme positions of the movable member, taking account of the movement amplitude required of the piston to impart a desired excitation to said load. | 10-15-2009 |
20100071359 | HYDRAULIC DEVICE AND WORK MACHINE - A hydraulic device has a first pump, a second pump, an operating state detector configured and arranged to detect an operating state, a connection switching unit configured and arranged to selectively connect the second pump to either a first hydraulic oil line or a second hydraulic oil line, and a switching controller configured to control, based on the operating state detected by the operating state detector, a switching operation of the connection switching unit The switching controller is further configured to inhibit the switching operation of the connection of the second pump when the detected operating state is such that at least one of clutches of a multi-stage transmission and a steering device is in a state transition or at least one brake of the steering device is being operated. | 03-25-2010 |
20110030364 | FLOW MANAGEMENT SYSTEM FOR HYDRAULIC WORK MACHINE - A flow management system capable of providing adjustable hydraulic fluid flow or pressure at a common line to supply bidirectional pumps in electro-hydrostatic actuation systems and conditioning re-circulated hydraulic fluid. The system enables flow sharing between multiple actuation systems and minimization of energy consumption by a power-on-demand approach and/or electrical energy regeneration while eliminating the need for an accumulator. The system has particular application to electro-hydrostatic actuation systems that typically include bi-directional electric motor driven pumps and unbalanced hydraulic actuators connected within closed circuits to provide work output against external loads and reversely recover energy from externally applied loads. | 02-10-2011 |
20110056194 | HYDRAULIC SYSTEM FOR HEAVY EQUIPMENT - Heavy equipment includes first and second hydraulic pumps, and first and second hydraulic actuators, where the first hydraulic actuator facilitates a first work function of the heavy equipment and the second hydraulic actuator facilitates a second work function of the heavy equipment. The heavy equipment further includes valving and a computerized controller. The valving is configured to allow the first hydraulic pump to be coupled to the first hydraulic actuator and the second hydraulic actuator, and to allow the second hydraulic pump to be coupled to the first hydraulic actuator and the second hydraulic actuator. The computerized controller is coupled to the valving, and has a logic module. The logic module provides instructions to the computerized controller to operate the valving as a function of inputs from an operator command, a sensor input, and prioritization logic associated with the first and second work functions, so as to optimize performance of the work functions facilitated by the hydraulic actuators with respect to available output of the hydraulic pumps. | 03-10-2011 |
20110088384 | Apparatus and Methods for Controlling Hydraulically-Powered Apparatus - In one aspect, the disclosure herein provides an apparatus that in one configuration includes a first hydraulic power unit for supplying a first fluid under pressure to a first chamber for controlling motion of a first movable member and a second hydraulic power unit for supplying a second fluid under pressure to a second chamber for controlling motion of a second movable member, an input device configured to provide an input signal for controlling the motions of the first and second movable members and a processor configured to: receive the input signal from the input device; and independently set, in response to the input signal from the input device, a first electrical actuator to control an amount and flow rate of the first fluid to the first hydraulic power unit and a second electrical actuator to control an amount and flow rate of the second fluid to the second hydraulic power unit for controlling the motion of the first and second movable members. | 04-21-2011 |
20110107756 | ELECTRO-HYDROSTATIC ACTUATOR EXCELLENT IN SNUBBING CHARACTERISTIC, AND DRIVE DEVICE USED FOR THE SAME, AND CONTROL METHOD USED FOR THE SAME - The present invention is to provide an electro hydrostatic actuator excellent in a snubbing characteristic including a cylinder type actuator main body | 05-12-2011 |
20120233997 | REGENERATIVE HYDRAULIC SYSTEMS AND METHODS OF USE - Hydraulic systems and methods for using such systems in a variety of machinery, including but not limited to machines having multiple functions performed by one or more hydraulic circuits. The systems enable valves and actuators within the systems to reconfigure themselves so that flow from assistive loads on one or more actuators can be used to move one or more other actuators subjected to a resistive load. | 09-20-2012 |
20130055704 | Apparatus for Controlling Raise Speed of Working Machine for Heavy Equipment - The present disclosure relates to an apparatus for controlling a raise speed of a working machine for heavy equipment that includes first and second pumps, a main control valve unit that includes two lift cylinder operation units connected with the first and second pumps and operating two lift cylinders and one tilt cylinder operation unit operating two tilt cylinders, a priority valve that is provided in a working fluid line between the second pump and the main control valve unit, and a lift lever that includes a remote control valve connected with the two lift cylinder operation units through a pilot oil line, respectively, and controlling the two lift cylinders through the two lift cylinder operation units, in which a valve control unit, which electrically controls the flow of pilot oil in proportion to the RPM of an engine to allow or stop the working fluid flowing from any one of the two lift cylinder operation units to the two lift cylinders, is disposed in any one of two pilot oil lines between the two lift cylinder operation units and the remote control valve of the lift lever. | 03-07-2013 |
20130074486 | MULTI-PUMP SYSTEM WITH PUMP-FLOW DIVERSION - A work vehicle has a pump group with two fixed-displacement pumps, an electro-hydraulic diverter openable to divert flow from one of the pumps to a fluid reservoir, and a controller configured to command the diverter to open. | 03-28-2013 |
20130291530 | BOOM-SWIVEL COMPOUND DRIVE HYDRAULIC CONTROL SYSTEM OF CONSTRUCTION MACHINE - Disclosed is a hydraulic control system for matching the drive speed of a boom up and a swing device according to the operation environment when compound-driving for manipulating boom and swing for excavation compensating error operation. The hydraulic control system of the present invention comprises: an operation mode selection switch for enabling the selection of an operation mode according to the operation environment; an electronic proportional pressure control valve for outputting a control signal pressure that is proportional to the manipulation of the operation mode selection switch when manipulating a boom operation lever for driving the boom up; a variable flow control valve that is placed on a flow channel between a first hydraulic pump and a spool for the swing device, and has an open area thereof that is variably matched proportional to the control signal pressure from the electronic proportional pressure control valve; and a controller having various types of operation modes previously set and stored thereon so as to control the flow being supplied to the spool for the swing device and a spool for the boom merge, according to the operation mode selected when manipulating the operation mode selection switch. | 11-07-2013 |
20140013736 | MIXER DRUM DRIVING DEVICE - A mixer drum driving device includes a mixer drum, a hydraulic motor, a hydraulic pump, an auxiliary hydraulic pump for rotating the mixer drum for mixing by supplying pressure oil to the hydraulic motor independently of the hydraulic pump, and a direct-current brush motor for driving and rotating the auxiliary hydraulic pump. The auxiliary hydraulic pump is driven and rotated by the direct-current brush motor when the engine stops during the rotation of the mixer drum for mixing. | 01-16-2014 |
20140026551 | HYBRID CONSTRUCTION MACHINE - A hybrid construction machine that enables to efficiently cool a generator motor, while suppressing an increase in the entire length of a power unit. A motor housing is provided with a bulging portion which is configured to axially bulge from the inner periphery of a motor side connection surface toward an engine over the entire circumference thereof around an axis, and to engage with the inside of an engine housing; and a coolant passage which is configured to flow a coolant for cooling a stator therethrough. The inner peripheral surface of the motor housing including the inner peripheral surface of the bulging portion is configured to come into plane contact with the outer peripheral surface of the stator. The coolant passage is disposed at a position axially displaced from the motor side connection surface. | 01-30-2014 |
20140238010 | CONTROL SYSTEM FOR OPERATING WORK DEVICE FOR CONSTRUCTION MACHINE - Disclosed is a control system for controlling flow so as to allow simultaneous usage of a parallel flow path and a tandem flow path thereby reducing loss of pressure inside a control valve, when simultaneously operating work devices having different operating pressures. A control system for operating the work device, according to the present invention, provides the control system for operating the work device for a construction machine, comprising: first and second hydraulic pumps that are connected to an engine; a revolution control valve, an arm control valve, and a left driving control valve, which are installed on a first center bypass path of the first hydraulic pump, and each of which is connected via the parallel flow path; a boom control valve, a bucket control valve, and a right driving valve, which are installed on a second center bypass path of the second hydraulic pump, and each of which is connected via the parallel flow path; a pressure generation device; a bleed flow path, which is formed on a control spool at a lower side of a boom of the boom control valve, for maintaining an open state of the second center bypass path without closing same, when the boom control valve is switched so as to lower the boom; and a center bypass switch valve, which is installed on the lowermost side of the second center bypass path and is switched by means of a control signal for switching the boom control valve. | 08-28-2014 |
20140245730 | PRIORITY CONTROL SYSTEM FOR CONSTRUCTION MACHINE - Disclosed is a lower track for mounting rubber pads on a track shoe to be attachable and detachable after assembling a steel plate which is adhered with divisionally formed rubber pads as a single unit without additionally perforating coupling through-holes in the track shoe when the rubber pad which forms the lower track and the track shoe which is formed of a metal material are coupled. The lower track of a crawler excavator according to the present invention comprises: first and second rubber pads which are divisionally formed; a first steel plate which supports the bottom surface of the first rubber pad by surrounding the same, and has first hooks formed on the bottom surface thereof and coupling holes formed in a connection stepped-portion. | 09-04-2014 |
20140366517 | SYSTEM FOR REDUCING FUEL CONSUMPTION IN EXCAVATOR - The present disclosure relates to a system for reducing fuel consumption in an excavator, and more particularly, to a system for reducing fuel consumption in an excavator, which may reduce fuel consumption when an excavator travels. | 12-18-2014 |
20150033727 | HYBRID CONSTRUCTION MACHINE - A hybrid construction machine includes first and second main pumps, first and second supply passages, first and second circuit systems, a hydraulic motor, a motor generator, an assist pump, a joint passage connected to the assist pump and branched off, first and second logic valves, a switching valve disposed in the other branch passage and switchable to a state where the assist pump is connected to the second supply passage on the upstream side of the second logic valve and a state where the second main pump is connected to the hydraulic motor, and a check valve. A poppet diameter of the first logic valve is smaller than that of the second logic valve. | 02-05-2015 |
20150047335 | MIXER DRUM DRIVING APPARATUS - A mixer drum driving apparatus includes an auxiliary fluid pressure pump that is provided independently of a fluid pressure pump and is capable of supplying a working fluid to a fluid pressure motor so as to cause a mixer drum to perform agitation rotation, a plurality of motors configured to drive the auxiliary fluid pressure pump to rotate, and a control unit that controls rotation of the mixer drum. When an engine is stopped during the agitation rotation of the mixer drum, the control unit drives the auxiliary fluid pressure pump to rotate by operating the plurality of motors selectively in accordance with a load of the mixer drum. | 02-19-2015 |
20150075150 | CLOSED HYDRAULIC CIRCUIT - The present invention relates to a closed hydraulic circuit between a hydraulic pump and a hydraulic motor that are connected to one another via working lines, a flushing pump being provided in order to feed a pressure medium into the working lines, and an output connection being provided in order to discharge excess pressure medium from the working lines. At least one hydraulic consumer, which is provided to convert at least some of the volume flow discharged from the hydraulic circuit into mechanical power, is connected downstream of the output connection. | 03-19-2015 |
20150135698 | HYDRAULIC VALVE ARRANGEMENT WITH CONTROL/REGULATING FUNCTION - The present invention relates to a hydraulic valve arrangement for controlling/regulating at least one hydraulic consumer of a mobile machine, with a summation interconnection of at least two hydraulic valves and at least one consumer interconnection of hydraulic valves, wherein the outputs of the summation interconnection are hydraulically connected with the inputs of the consumer interconnection, wherein at least one backflow valve is provided in the consumer interconnection. According to the invention, the at least one backflow valve for throttling a consumer return volume flow opens or closes in dependence on a consumer inflow pressure and comprises at least one main piston arranged in a bushing and at least two further pistons arranged in a lid separate from the bushing, wherein the main piston and the control piston interact with each other via a compression spring. | 05-21-2015 |
20150135699 | HYDRAULIC VALVE ARRANGEMENT WITH CONTROL/REGULATING FUNCTION - The present invention relates to a hydraulic valve arrangement for controlling/regulating at least one hydraulic consumer of a mobile machine, with a summation interconnection of at least two hydraulic valves and at least one consumer interconnection of hydraulic valves, wherein the outputs of the summation interconnection are hydraulically connected with the inputs of the consumer interconnection, wherein at least one backflow valve is provided in the consumer interconnection. According to the invention, the at least one backflow valve for throttling a consumer return volume flow opens or closes in dependence on a consumer inflow pressure and comprises at least one main piston arranged in a bushing and at least two further pistons arranged in a lid separate from the bushing. | 05-21-2015 |
20150330414 | VELOCITY CONTROL FOR HYDRAULIC CONTROL SYSTEM - A hydraulic drive system for an actuator uses a pair of pressure compensated hydraulic machines to control flow to and from the drive chambers of the actuator. The capacity of one of the machines is limited in a motoring mode to determine a maximum rate of efflux from one of the chambers. The pressure of fluid supplied to the other of said chambers is maintained at a predetermined level to provide motive force. The machines are mechanically coupled to permit energy recovery and charge an accumulator to store surplus energy. | 11-19-2015 |
20150354607 | HYDROMECHANICAL CONTINUOUSLY VARIABLE TRANSMISSION - The disclosure is directed to a transmission, and more particularly to a semi-Continually Variable Transmission (sCVT), a semi-Continuous, Variable Displacement Motor, a semi-Continuously Reciprocating Multiplex Pump (sCVDP) and an infinitely variable transmission (IVT). | 12-10-2015 |
20160025113 | Apparatus for Driving Work Machine - Provided is a driving device for a working machine, which can drive one or more hydraulic pumps in a large capacity range of as high efficiency as possible. In a driving device for a hydraulic excavator, a controller ( | 01-28-2016 |
20160047398 | APPARATUS FOR CONTROLLING HYDRAULIC PUMP FOR CONSTRUCTION MACHINE - The present disclosure relates to an apparatus for controlling a hydraulic pump for a construction machine. The apparatus for controlling the hydraulic pump for the construction machine according to the present disclosure includes: a hydraulic pump control device configured to generate first and second pump commands for controlling first and second hydraulic pumps so that the first and second hydraulic pumps generate pump torque corresponding to a request value; and a torque controller configured to generate first and second corrected pump commands, which are the corrected first and second pump commands, by a torque inclination map generated by reflecting a dynamic characteristic of an engine, and to provide the first and second corrected pump commands to the first and second hydraulic pumps. | 02-18-2016 |
20160097405 | HYBRID WORK MACHINE - A hybrid work machine includes: an engine controller ( | 04-07-2016 |
20160146227 | Pilot Circuit for Working Vehicle - The machine includes an operation selection switch to choose either an oil-pressured pilot operation or an electric operation, a control device to input an electric signal for traveling transmitted from an electric operation device and a selection signal from the operation selection switch. A third electro-magnetic valve may forbid outputting pilot pressure from a pilot valve, a first to fourth electro-magnetic proportional valve outputting a pilot pressure to the control valve for traveling based on the control signal from the control device and a first to fourth shuttle valve leading the output pilot pressure to the control valve for traveling. | 05-26-2016 |
20160146230 | HYDRAULIC PRESSURE CONTROL DEVICE FOR CONSTRUCTION MACHINERY - The present invention relates to a hydraulic pressure control device for construction machinery, comprising: a pilot pump; a swing motor for rotary-actuating an upper turning body; a brake control valve for controlling the direction of a hydraulic pressure of the pilot pump to operate a brake; a controller for receiving a command signal for driving the swing motor and applying the command signal to the brake control valve; a relief valve interposed between the brake control valve and the pilot pump; and a drain control valve, disposed in parallel with the brake control valve, for performing opening and closing operations so that the hydraulic pressure of the pilot pump can selectively return to a hydraulic tank in accordance with the state of the brake control valve, the drain control valve being opened for the hydraulic pressure to be discharged to the hydraulic tank without passing through the relief valve if the brake control valve is switched to brake the swing motor. | 05-26-2016 |
20160177539 | Working Machine | 06-23-2016 |
20160251833 | HYDRAULIC DRIVE SYSTEM OF CONSTRUCTION MACHINE | 09-01-2016 |
20160252107 | HYDRAULIC EXCAVATOR DRIVE SYSTEM | 09-01-2016 |
20190143540 | ACTUATOR DEVICE AND CONTROL METHOD | 05-16-2019 |
060429000 | With externally operated multiway valve changing the relationships of the motive fluid pressurizing or supplying means | 12 |
20090313987 | Driving Assistance System for Power Steering Wheel - The driving assistance system for power steering wheel provides various setting statuses of assisting power so that starting and stopping of the power assistance can be adjusted according to practical conditions. The adjustable contents can be set by manufactures, service technicians or drivers according to battery capacity, vehicle speed or both of them. The system can provide multiple control modes for power assistance to match various requirements. | 12-24-2009 |
20100107625 | TRANSMISSION CONTROL DEVICES AND SYSTEMS, AND METHODS OF ASSEMBLY AND USE THEREOF - Aspects of the present invention provide features for varying speeds available and/or range of operation of transmissions for use in high performance, increased efficiency, and/or other applications. Increased performance and/or efficiency may be obtained by using additional speeds or gear ranges to maintain drivetrain operation within maximum power and/or efficiency bands of internal combustion engine operation. | 05-06-2010 |
20110072810 | CONTROLLER OF HYBRD CONSTRUCTION MACHINE - Disclosed is a controller of a hybrid, construction machine wherein electric power is generated by utilizing the standby flow rate of first and second main pumps, and the standby flow rate is converted into energy. Pilot channels are connected to the upstream side of on/off valves which are closed when first and second main pumps ensure a standby flow rate, and a controller unit judges that the first and second main pumps are discharging at the standby low rate based on pressure signals from first and second pressure sensors, and brings first and second solenoid valves to an open position. | 03-31-2011 |
20120031087 | HYDRAULIC CIRCUIT WITH MULTIPLE PUMPS - A hydraulic circuit includes at least one actuator that may be powered for performing a function. A plurality of valves are associated with the at least one actuator for controlling a flow of fluid into and out of the at least one actuator. The hydraulic circuit also includes multiple pumps for supplying fluid to the at least one actuator. The multiple pumps includes a first pump for primarily powering the at least one actuator for movement in a first direction and a second pump for primarily powering the at least one actuator for movement in a second direction, opposite the first direction. | 02-09-2012 |
20120233998 | CONTROL SYSTEM FOR HYBRID CONSTRUCTION MACHINE - A regeneration switching valve which communicates with a neutral flow path and a tank at a normal position and cuts off communication between the neutral flow path and the tank to cause the neutral flow path to communicate with a hydraulic motor for power generation at a switched position is provided in at least one of first and second circuit systems including a plurality of control valves. | 09-20-2012 |
20140366518 | HYDRAULIC SYSTEM OF CONSTRUCTION MACHINE - The present disclosure relates to a hydraulic system of a construction machine. The hydraulic system of the construction machine includes: an electronic proportional pressure reducing valve configured to control a flow rate, to which a maximum pressure is input as a control current value, and which is set to a minimum flow rate; a gear pump configured to provide pilot operation oil to the EPPRV; a shuttle valve configured to compare a pressure of first pilot operation oil passing through the EPPRV and a pressure of a flow rate control signal, and output second pilot operation oil having the greater pressure; a hydraulic pump of which a swash plate angle is controlled by the second pilot operation oil; and a pump control device configured to control a pressure of the EPPRV to be decreased from a maximum pressure by a predetermined inclination when the flow rate control signal is generated. | 12-18-2014 |
20140373524 | CLUTCH TRANSMISSION - A clutch transmission, in particular a dual clutch transmission, includes a hydraulic circuit for actuating and/or cooling the clutch transmission. The hydraulic circuit includes at least one cooler for cooling a hydraulic medium conveyed by at least one pump, wherein a bypass with a thermostatic bypass valve is associated with the cooler. The thermostatic bypass valve has hereby three switching positions, wherein it can be moved to a first switching position by a spring force, from the first switching position to the second switching position by a thermal element against the spring force and from the second switching position to a third switching position against the spring force by a pressure difference exceeding a predeterminable limit value. | 12-25-2014 |
20150013320 | HYDRAULIC DRIVE SYSTEM - A hydraulic cylinder causes a work implement to be lowered due to the exhaust of hydraulic fluid from a first chamber and the supply of hydraulic fluid to a second chamber. A hydraulic fluid flowpath has a first flowpath and a second flowpath. The first flowpath connects a first pump port and the first chamber. The second flowpath connects a second pump port and the second chamber. The hydraulic fluid flowpath configures a closed circuit between a hydraulic pump and the hydraulic cylinder. A bleed-off flowpath branches off from the first flowpath. A portion of hydraulic fluid exhausted from the first chamber when lowering the work implement flows into the bleed-off flowpath. | 01-15-2015 |
20150040552 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE AND CONTROL DEVICE FOR SAME - A hydraulic circuit of a construction machine including center bypass passages, into which a pressurized oil from hydraulic pumps is supplied, includes a directional control valve group in tandem with the center bypass passages; a bleed-off valve on a downstream side of each center bypass passage; and a merging circuit that merges the pressurized oil supplied into one center bypass passage and that in another center bypass passage, wherein each directional control valve includes a first internal passage that flows the pressurized oil into the center bypass passages, and a second internal passage that supplies the pressurized oil to a hydraulic actuator, wherein the center bypass passages and the first internal passage form a parallel passage, wherein an opening area of the bleed-off valve is changed, wherein the merging circuit includes a merging directional control valve that controls an inflow direction of the pressurized oil to be merged. | 02-12-2015 |
20150128583 | TRAVEL CONTROL VALVE - A travel control valve includes a valve body and a spool. The valve body includes a first pump port connected on an upstream side from a drive control valve, a first connection port connected on a downstream side from the drive control valve, a second pump port connected to a second pump, and a second connection port connected to a second circuit system. The travel control valve can switch a communication opening between the first pump port and the first connection port to a large opening throttle position in which the communication opening remains smaller than that between the second pump port and the second connection port, and a small opening throttle position in which the communication opening remains smaller than that in the large opening throttle position. | 05-14-2015 |
20150315768 | CONSTRUCTION MACHINE WITH FLOATING FUNCTION - Disclosed is a construction machine with a floating function for performing soil preparation or the like for flattening the ground or the like using a dozer blade. The construction machine with a floating function according to the present invention comprises: a hydraulic pump and a pilot pump; a dozer cylinder connected to the hydraulic pump so as to move the dozer blade in the vertical direction; a control valve arranged in a channel between the hydraulic pump and the dozer cylinder; a dozer check valve arranged in the channel between the control valve and the dozer cylinder; a return check valve arranged in the channel between the control valve and a hydraulic tank; a solenoid valve for floating arranged in a signal path between the pilot pump and the dozer check valve such that the solenoid valve is capable of opening and closing; a channel for floating, one end of which is connected to the hydraulic tank and the other end of which is connected to the channel interconnecting the control valve and the dozer cylinder; and a check valve arranged in the channel for floating so as to supply working fluid to the dozer cylinder through the channel for floating from the hydraulic tank in a floating mode, and cut off the channel for floating when the floating mode is cancelled. | 11-05-2015 |
20160032947 | CONSTRUCTION MACHINE - A hydraulic excavator includes control valves connected to a head-side chamber of a boom cylinder, an operating unit configured to switch the control valves, lock valves each provided between the head-side chamber and each of the control valves, and an operation control unit that controls the operation of the lock valves. The lock valves each have a valve element that is configured to move between a locking position at which the discharge of hydraulic oil from the head-side chamber is restricted and an unlocking position at which the discharge of the hydraulic oil from the head-side chamber is allowed. The operation control unit controls the operation of the lock valves so that the valve elements move from the locking position to the unlocking position at different points in time when the operating unit is operated. | 02-04-2016 |
060430000 | Pressure or volume responsive means shifts the relationship | 10 |
20080256942 | Hydraulic system and automatic gearbox - A hydraulic system including a multi-flow hydraulic pressure supply unit, especially a dual-flow hydraulic pressure supply unit, such as a pump, by which a volumetric flow of pressurized fluid is supplied to a hydraulic-fluid-operated device. A valve arrangement is provided either for switching between the individual pump flows or for interconnecting the individual pump flows. | 10-23-2008 |
20100287924 | DUAL PUMP HYDRAULIC SYSTEM - A dual pump hydraulic system is provided for a vehicle driven by an internal combustion engine. The system includes a first circuit with a first high pressure pump supplying hydraulic fluid to the first subsystem at a higher pressure. The system also includes a second circuit with a second lower pressure pump supplying hydraulic fluid to the second subsystem at a second pressure. A first valve controls communication between the first pump and the second circuit. A second valve is operable to communicate the second pump with the first circuit when pressure in the first circuit is less than a second threshold pressure or when commanded by a control unit. A check valve prevents fluid flow from the first circuit back into to the second valve. | 11-18-2010 |
20120137670 | POWER 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; a passage to supply pressure from the mechanical pump to the hydraulic servo; a check valve in the passage that allows supply of the pressure from the mechanical pump to the hydraulic servo and prohibits supply of the pressure from the electric pump to the mechanical pump, and the switching mechanism either shuts off or allows communication through the passage based upon the signal pressure. | 06-07-2012 |
20140345266 | HYDRAULIC STEERING DEVICE - A hydraulic steering device is provided comprising a supply port arrangement having a supply port (P) and a return port (T), a working port arrangement having two working ports (L, R), direction valve means ( | 11-27-2014 |
20140366519 | HYDRAULIC CLOSED CIRCUIT SYSTEM - A hydraulic closed circuit system using a single rod type hydraulic cylinder prevents hunting of a flushing valve due to a delay in response of the flushing valve and circuit pressure pulsations, thereby preventing a decreasein operability of the hydraulic cylinder. A single rod type hydraulic cylinder is connected to a hydraulic pump via two hydraulic lines. A flushing valve is connected between the hydraulic lines and a tank; and a control unit is configured to add a predetermined control parameter to a pressure in a lower-pressure hydraulic line of the two hydraulic lines. The magnitude of a pressure in the higher-pressure hydraulic line of the two hydraulic lines is compared with the magnitude of a compensation pressure to which the control parameter has been added, and the flushing valve is switched when the compensation pressure and the higher-pressure hydraulic line pressure are found to be reversed in magnitude. | 12-18-2014 |
20150040553 | HYBRID WORKING MACHINE - Pressure sensors are provided to detect the delivery pressure of a hydraulic pump, the output pressure of an engine revolution speed detecting valve, and the output pressure of a differential pressure reducing valve generating the differential pressure between the delivery pressure of the hydraulic pump and a maximum load pressure. A vehicle controller calculates virtually the displacement of the hydraulic pump by use of the detected pressures and an equation of motion about a swash plate of the hydraulic pump, calculates the power need of the hydraulic pump and the output of the engine using these values, and switches a motor between powering and generation control in accordance with the result of a comparison between the pump power need and the engine output. In this manner, the displacement of the hydraulic pump without using sensors to detect the tilting angle of the swash plate of the hydraulic pump. | 02-12-2015 |
20150059330 | FLUID DELIVERY SYSTEM - A fluid delivery system includes a first hydraulic circuit, and a second hydraulic circuit. The first hydraulic circuit includes a first hydraulic pump, and a first hydraulic motor. The first hydraulic motor is fluidly connected to the first hydraulic pump and is configured to be driven by the first hydraulic pump. The second hydraulic circuit includes a second hydraulic pump, and a second hydraulic motor. The second hydraulic pump is mechanically coupled to the first hydraulic motor and configured to be driven by the first hydraulic motor. The second hydraulic motor is disposed in loop with the second hydraulic pump and configured to be driven by the second hydraulic pump. The fluid delivery system further includes a delivery pump mechanically coupled to the second hydraulic motor and fluidly connected to a fluid source. The delivery pump is configured to deliver a pressurized fluid. | 03-05-2015 |
20150107236 | HYDRAULIC CLOSED CIRCUIT SYSTEM - In a hydraulic closed circuit system with hydraulic pumps which maintains a well-balanced flow rate by automatically controlling the flow rate, a first hydraulic pump is connected to a hydraulic cylinder device such that the hydraulic closed circuit is made, a second hydraulic pump is connected at one of paired delivery ports to a bottom side of the hydraulic cylinder device and at the other of the ports to a tank, and a prime mover drives the first and second hydraulic pumps and recovers motive power from these pumps. A pump capacity control unit detects a moving direction of the hydraulic cylinder device, and a pressure in a lower-thrust side of the device, and controls a capacity of the second hydraulic pump so that the flow rate during the extension/retraction of the hydraulic cylinder device becomes balanced between the first and second hydraulic pumps and the hydraulic cylinder device. | 04-23-2015 |
20150377260 | HYDRAULIC POWER SYSTEM - A hydraulic actuation system includes a differential unit having a hydraulically-actuated differential, a power steering unit, a hydraulic pump, a reservoir, a controller, an electronically-controlled flow control manifold, and a proportional pressure control solenoid valve. A flow control manifold may control fluid flow to the power steering unit and the differential. The manifold may include a manifold inlet connected to a pump; first manifold outlet connected to a differential; second manifold outlet connected to a reservoir; third manifold outlet connected to a power steering unit; two-way solenoid valve connected to a manifold inlet and controlled by a controller; flow control valve connected to a two-way solenoid valve and a first manifold outlet; and a pressure differential sensing valve connected to a two-way solenoid valve, the manifold inlet, and the third manifold outlet. A proportional pressure control solenoid valve may connect the first manifold outlet and the differential. | 12-31-2015 |
20160102686 | HYDRAULIC SYSTEM FOR CONSTRUCTION EQUIPMENT - The present disclosure relates to a hydraulic system for construction equipment, and more particularly, to a hydraulic system, in which an actuator is controlled by a pump/motor. The hydraulic system for construction equipment according to the present disclosure includes logic valves in first and second hydraulic lines provided to an actuator, respectively, and when it is desired to operate the actuator in a state where an operation of the actuator is stopped by closing the logic valves, a pressure difference may be resolved by increasing pressure in sections of a pump/motor and the logic valves in advance even if a load is applied to the actuator, and thus the actuator may implement a desired operation without being affected by the load. That is, it is possible to improve operation controllability of the actuator. | 04-14-2016 |