Class / Patent application number | Description | Number of patent applications / Date published |
060421000 | With plural pump or motive fluid source relationships selected by multiway valve | 27 |
20080223026 | HYDRAULIC POWER MANAGEMENT SYSTEM - A machine having a hydraulic power management system. The machine includes an internal combustion engine driving first and second fixed displacement pumps to produce a combined flow of pressurized fluid. Main and auxiliary implements are operable in response to a flow of pressurized fluid, and a control valve selectively directs the combined flow to the main and auxiliary implements. A power management system is operable to stop the flow of pressurized fluid to the main implement from the second pump when the pressure of the combined flow exceeds a pressure indicative of the impending engine stall. A means for providing the combined flow to the auxiliary implement without regard to the pressure of the combined flow is also provided, and may take the form of a power management override or bypass mechanism. | 09-18-2008 |
20080236154 | Hydraulic circuit for construction equipment - A hydraulic circuit for construction equipment is disclosed, which can prevent an abrupt rotation of a swing device when a switching valve for the swing device is shifted in a state that switching valves for a traveling device and a working device have been shifted. The hydraulic circuit includes first to fourth hydraulic pumps; first to fourth switching valves installed in the first to fourth hydraulic pumps, respectively, and shifted to control hydraulic fluid fed to working devices or traveling devices; a confluence switching valve installed in the third hydraulic pump and shifted to supply the hydraulic fluid to the working devices on the first and second hydraulic pump sides; signal lines for the traveling devices and the working devices; a first valve connected between the signal line for the traveling device and an intersection between the signal line for the confluence switching valve and a tank line; and a second valve installed in a flow path between the first valve and the tank line, shifted to discharge pressure in the signal line for the confluence switching valve to the tank line or to block the flow path to form the signal pressure in the signal line for the confluence, in response to a supply of the signal pressure. | 10-02-2008 |
20080289325 | Traveling device for crawler type heavy equipment - A traveling device for crawler type heavy equipment is provided, which can improve the manipulability by preventing an abrupt decrease/increase of a traveling speed of the equipment when a combined operation, in which a left/right traveling device and a working device are simultaneously driven, is performed. The traveling device for crawler type heavy equipment includes first and second variable displacement hydraulic pumps, switching valves for left and right traveling motors and working devices, a straight traveling valve shifted to supply hydraulic fluid to the switching valves for the left and right traveling motors and to the switching valves for the working devices in response to a signal pressure in a combined working mode, a variable orifice shifted to intercept the supply of the hydraulic fluid toward the traveling device in response to the signal pressure in the combined working mode if a load pressure of the working device is relatively higher than that of the traveling device, a mode selection device for selecting a working mode, and a controller for outputting control signals to electro proportional valves and to electric control valves so as to control discharged flow rates of the first and second hydraulic pumps in accordance with the selected working mode. | 11-27-2008 |
20080302097 | Hydraulic Unit - The invention relates to a hydraulic group comprising a reservoir ( | 12-11-2008 |
20090000291 | Arrangement and Method for Delivering Hydraulic Fluid in a Work Vehicle - An arrangement for delivering hydraulic fluid to at least one hydraulic actuator of a work vehicle for moving a work implement and/or steering the vehicle includes at least two pumps which are adapted to be operatively driven by a power source and adapted to operatively drive said at least one hydraulic actuator via hydraulic fluid. A first pump is operated with a phase shift relative to a second pump. | 01-01-2009 |
20090056324 | Hydraulic control device of construction machinery - A hydraulic control device of construction machinery having a main merging/diverging valve interposed in a connecting oil path connecting discharge oil paths of first and second hydraulic pumps in a merging position, operating levers for corresponding works operated to actuate plural actuators, an operating condition judging section judging a lever operating condition of each operation lever, a pattern collating section selecting an operating pattern matching an actual operation pattern from set and stored various operation patterns corresponding the operating conditions in a controller. When a load pressure of each actuator is high, a discharge pressure of each discharge oil path is also high, and when a total of the discharge pressures exceeds a predetermined set pressure, the main merging/diverging valve is switched to a diverging position, and when the total of the discharge pressures drops to below the set pressure, the main merging/diverging valve is switched to the merging position. | 03-05-2009 |
20090056325 | HYDRAULIC FLOW CONTROL SYSTEM - A hydraulic system for use in a work vehicle with a powered implement is disclosed. In one embodiment, the hydraulic system may include a first hydraulic circuit including a first hydraulic pump with a low pressure and low flow output, switch and valve; a second hydraulic circuit including a second hydraulic pump with a high flow and high pressure output, switch and valve; and a third hydraulic circuit including a third hydraulic pump with a high flow and high pressure output, switch and valve. The first, second, and third circuits each include an output selectively combinable with each other by an operator control which controls the switch and valve configurations. The hydraulic system has several configurations. A first configuration is selectable to provide low pressure and low flow output to the implement, a second configuration is selectable to provide high pressure and high flow output to the implement from one of said second and third hydraulic circuits, a third configuration is selectable to provide high pressure and high flow output to the implement combining the output from the second and third hydraulic circuits, and a fourth configuration is selectable to provide low pressure and high flow output to the implement from said first, second and third hydraulic circuits. | 03-05-2009 |
20090071141 | HYDRAULIC CIRCUIT FOR HEAVY EQUIPMENT - A hydraulic circuit for heavy equipment is provided, which can prevent signal pressure exceeding a predetermined pressure from being formed in a pilot signal path provided in a switching valve to sense whether the switching valve has been shifted in a hydraulic system that minimizes the discharge flow rate of a hydraulic pump when a working device such as a boom is not driven. The hydraulic circuit includes first to fourth hydraulic pumps connected to an engine, first switching valves installed in flow paths of the first hydraulic pump and shifted to control hydraulic fluid fed to a working device, second switching valves installed in flow paths of the second hydraulic pump and shifted to control hydraulic fluid fed to a working device, third switching valves installed in flow paths of the third hydraulic pump and shifted to control hydraulic fluid fed to a swing device, a pilot signal path for sensing whether the first to third switching valves are shifted, a throttling part installed in the pilot signal path to form a signal pressure, and a valve installed in a parallel flow path branch-connected to the pilot signal path and supplying the signal pressure in the pilot signal path to the pilot signal pressure supply path when a signal pressure exceeding a predetermined pressure is formed in the pilot signal path. | 03-19-2009 |
20100037603 | HYDRALIC TWO-CIRCUIT SYSTEM AND INTERCONNECTING VALVE SYSTEM - A hydraulic two-circuit system ( | 02-18-2010 |
20100043421 | METHOD FOR OPERATING A HYDRAULIC SYSTEM, AND HYDRAULIC SYSTEM - A method for operating a hydraulic system having at least one supply device, in particular a hydraulic pump ( | 02-25-2010 |
20100083649 | Configurable Hydraulic System - A configurable hydraulic system facilitates a variety of oilfield cementing and other oilfield or related applications. The system employs a plurality of prime movers to drive a plurality of loads. The plurality of prime movers and loads are coupled with a configurable hydraulic system that maintains a separate, sealed hydraulic system associated with each prime mover. The configurable hydraulic system also enables the load configuration driven by each prime mover to be changed without losing the benefit of a separate, sealed hydraulic system associated with each specific prime mover. | 04-08-2010 |
20110192155 | Hydraulic Drive Device for Hydraulic Excavator - The operability when performing a combined arm-crowd and bucket operation can be improved. A hydraulic drive device for a hydraulic excavator includes: a bucket directional control valve and a second arm directional control valve, which are connected in parallel tandem with a first hydraulic pump; a first arm directional control valve that is connected to a second hydraulic pump; and a flow rate restriction device that restricts the flow rate of pressure oil supplied to the second arm directional control valve, during crowd operation of a bucket. This flow rate restriction device includes a variable throttle whose opening is controlled so as to become smaller as a bucket operating device is operated to the crowd side, the variable throttle being provided in a bypass path connecting to the supply port of the second arm directional control valve. | 08-11-2011 |
20110258996 | SYSTEM AND METHODS FOR OPTIMIZING EFFICIENCY OF A HYDRAULICALLY ACTUATED SYSTEM - Systems and methods for efficiently operating a hydraulically actuated device/system are described herein. For example, systems and methods for efficiently operating a gas compression and expansion energy storage system are disclosed herein. Systems and methods are provided for controlling and operating the hydraulic actuators used within a hydraulically actuated device/system, such as, for example, a gas compression and/or expansion energy system, within a desired efficiency range of the hydraulic pump(s)/motor(s) used to supply or receive pressurized hydraulic fluid to or from the hydraulic actuators. In such a system, a variety of different operating regimes can be used depending on the desired output gas pressure and the desired stored pressure of the compressed gas. Hydraulic cylinders used to drive working pistons within the system can be selectively actuated to achieve varying force outputs to incrementally increase the gas pressure within the system for a given cycle. | 10-27-2011 |
20120079821 | EXCAVATOR DRIVE SYSTEM WITH BI STATE MOTOR TRANSFER SWITCHES - An excavator drive system wherein one of a pair of propulsion motors shares one of a pair of inverter power sources with another of a pair of motors dedicated to crowd and hoist motions. A pair of non-volatile bi-state switches, triggered under control of a controller, allow sharing of inverters between hoist and propel | 04-05-2012 |
20120180472 | Fixed/variable hybrid system - A fixed/variable hybrid system has modified constant flow open center hydraulic valves (“fixed/variable valves”), including an open center core, spools, a power core, and a tank galley. A small fixed displacement pump provides fluid at a constant rate to the open center core. A variable displacement piston pump provides fluid directly to the power core as needed. Activation of spools partially restricts the open center core causing an increase in fluid pressure that is communicated to the variable displacement piston pump's load sense signal port, causing the pump to increase fluid flow and pressure to the power core. Activated spools direct pressurized fluid from the power core to the applications through selected hydraulic ports. Activated spools also direct fluid flow from selected hydraulic ports via the tank galley to a hydraulic tank. Pumping the majority of fluid only on an as-needed basis results in significant efficiencies. | 07-19-2012 |
20120186243 | HYDRAULIC SYSTEM HAVING AT LEAST ONE DRIVE MACHINE - The invention relates to a hydraulic system having a pump and at least two working machines, in particular two working machines embodied as hydraulic cylinders. Each working machine is connected by pressure lines to the associated drive machine via two connectors that serve as an inflow or return. At least one valve is associated with each working machine, for adjusting the operating state of the working machine. In the context of an elevating work platform the connector which serves as an outflow in a working state of that working machine that is brought about or at least assisted by gravity is connected via a bypass, circumventing the drive machine, directly to the connector, serving as inflow in the context of a desired operating state, of another working machine, so that the hydraulic fluid flowing out from the first working machine flows for actuation of the other working machine. | 07-26-2012 |
20120233996 | SYSTEM FOR ALLOCATING FLUID FROM MULTIPLE PUMPS TO A PLURALITY OF HYDRAULIC FUNCTIONS ON A PRIORITY BASIS - A valve assembly has a flow summation node coupled to a displacement control port of the first pump. Each valve in the assembly has a variable metering orifice controlling flow from an inlet to a hydraulic actuator and has a variable source orifice conveying fluid from a supply conduit to a flow summation node. The source orifice enlarges as the metering orifice shrinks. Each valve includes a variable bypass orifice and the bypass orifices of all the control valves are connected in series forming a bypass passage between a bypass node and a tank. The bypass node is coupled to the flow summation node and receives fluid from a second pump. At each valve, a source check valve conveys fluid from the supply conduit to the inlet and a bypass supply check valve conveys fluid from the bypass passage to the inlet. | 09-20-2012 |
20140165549 | HYDRAULIC SYSTEM HAVING MULTIPLE CLOSED LOOP CIRCUITS - A hydraulic system is disclosed. The hydraulic system may have a first pump, a boom cylinder, and a first closed loop fluidly connecting the first pump to the boom cylinder. The hydraulic system may also have a second pump, a swing motor, and a second closed loop fluidly connecting the second pump to the swing motor. The hydraulic system may further have a third pump, an auxiliary actuator, and a third closed loop fluidly connecting the third pump to the auxiliary actuator. The hydraulic system may additionally have a combining valve configured to selectively connect the second closed loop to the first closed loop during a boom raising operation, and a control valve configured to selectively connect the third closed loop to the first closed loop during a boom lowering operation. | 06-19-2014 |
20150089935 | CONTROL VALVE APPARATUS OF POWER SHOVEL - A control valve apparatus includes a second-working-actuator acceleration control valve connected to a first working control valve in parallel. The second-working-actuator acceleration control valve includes pilot chambers receiving a pilot pressure for switching first and second working control valves and a flow channel that guides a pressure fluid of a first pump port to an entrance port side of the second working control valve. The second-working-actuator acceleration control valve is switchable between a first priority position in which a pressure fluid is guided to the first working control valve with a higher priority than the second working control valve and a second priority position in which a pressure fluid is guided to the second working control valve with a higher priority than the first working control valve. | 04-02-2015 |
20150096290 | HYDRAULIC SYSTEM - A hydraulic system, preferably for actuating and engaging a mobile slurry pump, includes a primary circuit, actuating a first hydraulic consumer, which circuit has a hydraulic drive assembly including at least one motor-driven hydraulic pump. The hydraulic system further includes a secondary circuit, actuating a second hydraulic consumer, which circuit has a second hydraulic drive assembly including at least one additional motor-driven hydraulic pump. In a first operating state, hydraulic oil from a common tank can be admitted to the hydraulic consumers arranged in the primary circuit and in the secondary circuit via the hydraulic drive assemblies thereof, independently of one another. In a second operating state, a portion of the hydraulic oil is supplied from the primary circuit to the secondary circuit to actuate the second consumer. | 04-09-2015 |
20150113970 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINERY - Disclosed is a hydraulic system for performing land preparation works by means of a simultaneous boom-up and arm-in operation. The hydraulic system according to the present invention includes: an arm cylinder and a boom cylinder that are connected to first and second hydraulic pumps, respectively; a first boom control valve that is disposed in the discharge flow path of the second hydraulic pump; a second boom control valve that is disposed in the discharge flow path of the first hydraulic pump and causes the working fluid of the first hydraulic pump to converge with the working fluid which is supplied from the second hydraulic pump to the boom cylinder; a first arm control valve that is disposed in the discharge flow path of the first hydraulic pump; a second arm control valve that is disposed in the discharge flow path of the second hydraulic pump and causes the working fluid of the second hydraulic pump to converge with the working fluid which is supplied from the first hydraulic pump to the arm cylinder; a recycle valve that is disposed in the flow path between the working fluid inlet port of the first arm control valve and a hydraulic tank; and a second boom control valve spool having a parallel pressure section in which the boom-up pilot pressure does not increase with respect to the boom-up strokes during the simultaneous boom-up and arm-in operation. | 04-30-2015 |
20150330059 | LIQUID-PRESSURE DRIVE SYSTEM AND CONSTRUCTION MACHINE INCLUDING SAME - In a hydraulic drive system, hydraulic oil discharged from an actuator pump is supplied to an actuator via an actuator drive circuit. In the hydraulic drive system, the hydraulic oil discharged from a fan pump is supplied to a cooling fan motor via a fan drive circuit, and the cooling fan motor rotates a cooling fan at a rotational speed corresponding to the flow rate of the hydraulic oil supplied to the cooling fan motor. A merge circuit connects the actuator drive circuit and the fan drive circuit to each other to cause the hydraulic oil flowing through the actuator drive circuit to merge into the hydraulic oil flowing through the fan drive circuit. When the merge condition is satisfied, the controller controls the merge circuit to connect the actuator drive circuit and the fan drive circuit to each other. | 11-19-2015 |
20150345518 | DEVICE FOR VARYING THE VOLUMES OF A FIRST HYDRAULIC MACHINE AND A SECOND HYDRAULIC MACHINE - A device for varying the swept volumes of first and second hydraulic machines, whose swept volumes depends upon pivoting positions of adjustable axes thereof which can be connected to one another by first and second lines. The axes can be coupled to a piston-cylinder device which is adjustable by a control valve unit for pivoting the axes. Pressures in the area of the hydraulic machines can be limited by the control valve unit. The control valve unit can be coupled to a respective first or second line with the highest pressure. A device for determining an existing actual pressure is located upstream of the control valve unit, at least in the area of one of the first and the second lines that connects with the first and the second hydraulic machines. The control valve unit can be actuated based on the actual pressure value determined by the device. | 12-03-2015 |
20150354603 | HYBRID CONSTRUCTION MACHINE - This invention provides a hybrid construction machine including a swing structure, a hydraulic pump, a hydraulic swing motor driving the swing structure using hydraulic fluid from the hydraulic pump, an electric swing motor driving the swing structure in conjunction with the hydraulic swing motor, a boom cylinder operated simultaneously with the swing structure at times and driven by the hydraulic fluid from the hydraulic pump, a first directional control valve controlling flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic swing motor, a second directional control valve controlling the flow of the hydraulic fluid returning from the hydraulic swing motor, and a controller and solenoid pressure reducing valves which prevent operation of the second directional control valve when the boom cylinder is operated simultaneously with the swing structure. | 12-10-2015 |
20150377258 | Hydraulic Drive System for Construction Machine - In addition to a main pump | 12-31-2015 |
20160115974 | HYDRAULIC DRIVE SYSTEM FOR CONSTRUCTION MACHINE - To cope with a variety of flow rate balance required of two actuators flexibly in combined operations driving two actuators of high maximum demanded flow rates at the same time while suppressing the wasteful energy consumption caused by the throttle pressure loss in a pressure compensating valve, the arrangement is such that when the demanded flow rate of a boom cylinder | 04-28-2016 |
20160160883 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE - A hydraulic circuit for a construction machine is disclosed, which can prevent a loss of pressure during a combined work. The hydraulic circuit includes a variable displacement hydraulic pump, at least two hydraulic actuators driven by hydraulic fluid that is supplied from the hydraulic pump, control valves installed in a center bypass path of the hydraulic pump and shifted to control a start, a stop, and a direction change of the hydraulic actuators, parallel flow paths having inlets branched and connected to predetermined positions on an uppermost stream side of the center bypass path and outlets connected to inlet ports of the control valves, bleed-off paths formed on the control valves other than the lowermost downstream side control valve among the control valves to selectively communicate with the center bypass path, the bleed-off paths communicating with the center bypass path when the plurality of control valves are shifted for a combined work, and a switching valve installed on a lowermost downstream side of the center bypass path to intercept the center bypass path when pilot signal pressure is applied. | 06-09-2016 |