Patent application number | Description | Published |
20080295681 | Hydraulic system having an external pressure compensator - A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid and a fluid actuator with a first chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber. The first valve further includes a first element movable between a flow passing, at which fluid from the source flows to the first chamber, and a flow blocking position, at which fluid from the source is blocked from the first chamber and a second element configured to selectively drain a control passageway associated with the first element to cause the first element to move. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first valve dependent upon the pressure of the control passageway. | 12-04-2008 |
20090071144 | Actuator control system implementing adaptive flow control - An actuator control system is disclosed. The actuator control system may have a pump and at least one actuator. The actuator control system may further have an actuator valve configured to control the at least one actuator. The actuator control system may also have a pump pressure sensor configured to determine a pump pressure value and a load pressure sensor configure to determine a load pressure value. The actuator control system may additionally have a controller configured to receive the pump pressure value and the load pressure value. The controller may further be configured to compare the pump pressure value and the load pressure value, and selectively implement a primary control strategy and a secondary control strategy based on the comparison. | 03-19-2009 |
20090217653 | Control system for recovering swing motor kinetic energy - This disclosure relates to a hydraulic system and method that converts the kinetic energy generated by the operation of a swing motor into hydraulic potential energy and reuses the hydraulic potential energy for swing motor acceleration. An accumulator can be provided for storing exit oil from the swing motor that is pressurized by the inertia torque applied on the moving motor via movement of an upper structure of a machine. The pressurized oil in the accumulator can be reused to accelerate the swing motor by supplying pressurized oil to the swing motor. | 09-03-2009 |
20100107623 | HYDRAULIC SYSTEM HAVING AN EXTERNAL PRESSURE COMPENSATOR - A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid and a fluid actuator with a first chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber. The first valve further includes a first element movable between a flow passing, at which fluid from the source flows to the first chamber, and a flow blocking position, at which fluid from the source is blocked from the first chamber and a second element configured to selectively drain a control passageway associated with the first element to cause the first element to move. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first valve dependent upon the pressure of the control passageway. | 05-06-2010 |
20120151904 | HYDRAULIC CONTROL SYSTEM HAVING ENERGY RECOVERY - A hydraulic control system for a machine is disclosed. The hydraulic control system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, a swing motor configured to receive the pressurized fluid and swing a body of the machine relative to an undercarriage, and a tool actuator configured to receive the pressurized fluid and move a tool relative to the body. The hydraulic control system may also have an energy recovery device configured to convert hydraulic energy to mechanical energy, a first accumulator configured to store waste fluid received from the swing motor, and a second accumulator configured to store waste fluid received from the tool actuator. Stored waste fluid from at least one of the first and second accumulators may be selectively discharged into the energy recovery device. | 06-21-2012 |
20120152368 | Independent Metering Valve with Flow Limiter - An independent metering valve (IMV) assembly is disclosed that includes a metering stem including an inlet. The IMV assembly also includes a hydro-mechanical control valve in communication with a fluid source and the inlet. The control valve also including a spool with a closed end and an open end. The control valve includes a biasing member that biases the control valve or spool towards an open position thereby establishing communication between the fluid source and the inlet. The control valve also including a load signal line providing communication between an outlet of the control valve upstream of the inlet and the closed end of the spool. Wherein high pressure in the load signal line allowing the control valve to move towards a closed position thereby overcoming bias of the biasing member and reducing flow to the inlet during a high pressure condition. | 06-21-2012 |
20130000094 | HYDRAULIC CONTROL SYSTEM HAVING ENERGY RECOVERY KIT - An energy recovery retrofit kit for a hydraulic control system is disclosed. The energy recover retrofit kit may have a first accumulator and a second accumulator. The energy recover retrofit kit may also have a recovery valve block fluidly connectable between an existing pump and an existing motor of the hydraulic system. The recovery valve block may be configured to selectively fluidly communicate the first and second accumulators with the existing motor. | 01-03-2013 |
20130000289 | HYDRAULIC CONTROL SYSTEM HAVING SWING MOTOR ENERGY RECOVERY - A hydraulic control system for a machine is disclosed. The hydraulic control system may have a work tool movable to perform an excavation cycle having a plurality of segments, a motor configured to swing the work tool during the excavation cycle, and a pump configured to pressurize fluid directed to drive the motor. The hydraulic control system may also have at least one accumulator configured to selectively receive fluid discharged from the motor and to discharge fluid to the motor during the plurality of segments, and a controller configured to implement a plurality of modes of operation. Each of the plurality of modes of operation includes a different combination of segments during which the at least one accumulator receives and discharges fluid. | 01-03-2013 |
20130000290 | ENERGY RECOVERY SYSTEM HAVING ACCUMULATOR AND VARIABLE RELIEF - A swing energy recovery system for a machine is disclosed. The swing energy recovery system may have a pump configured to pressurize fluid, a motor driven by a flow of pressurized fluid from the pump, and an energy recovery arrangement configured to receive pressurized fluid discharged from the motor and selectively supply pressurized fluid to the motor. The swing energy recovery system may also have a pressure relief valve associated with the motor, and a controller in communication with the energy recovery arrangement and the pressure relief valve. The controller may be configured to selectively adjust a setting of the pressure relief valve based on an operating condition of the energy recovery arrangement. | 01-03-2013 |
20130004278 | HYDRAULIC CONTROL SYSTEM HAVING SWING ENERGY RECOVERY - A hydraulic control system for a machine is disclosed. The hydraulic control system may have a pump configured to pressurize fluid, and a motor driven by a flow of pressurized fluid from the pump. The hydraulic control system may also have a first accumulator configured to receive pressurized fluid discharged from the motor and to selectively supply pressurized fluid to the motor, and a second accumulator configured to receive pressurized fluid discharged from the motor and selectively supply pressurized fluid to the motor. | 01-03-2013 |
20130004280 | HYDRAULIC CONTROL SYSTEM HAVING SWING MOTOR ENERGY RECOVERY - A hydraulic control system for a machine is disclosed. The hydraulic control system may have a work tool movable through segments of an excavation cycle, a motor configured to swing the work tool during the excavation cycle, at least one accumulator configured to selectively receive fluid discharged from the motor and to discharge fluid to the motor during the excavation cycle, and a controller. The controller may be configured to receive input regarding a current excavation cycle of the work tool, and make a determination based on the input that the current excavation cycle is associated with one of a set of known modes of operation. The controller may be further configured to cause the at least one accumulator to receive fluid and discharge fluid during different segments of the excavation cycle based on the determination. | 01-03-2013 |
20130152565 | HYDRAULIC SYSTEM HAVING ENERGY RECOVERY - A hydraulic system for a machine is disclosed. The hydraulic system may have a pump configured to pressurize fluid, a swing motor driven by pressurized fluid to swing a body of the machine relative to an undercarriage, and a first circuit fluidly connecting the pump to the swing motor. The hydraulic system may also have an energy recovery motor mechanically connected to the swing motor, at least one accumulator, and a second circuit fluidly connecting the at least one accumulator to the energy recovery motor. | 06-20-2013 |
20130247999 | HYDRAULIC ACCUMULATOR PRE-CHARGE PRESSURE DETECTION - A system including a hydraulic accumulator, a pressure sensor, a fluid source and a data processor to detect a pre-charge pressure is provided. The hydraulic accumulator includes first and second fluid chambers and a separator therebetween. The hydraulic accumulator has an associated pre-charge pressure. The pressure sensor is connected to the first fluid chamber. The data processor is connected to the pressure sensor. The data processor is configured to determine a first and second rate of pressure changes, and a transition pressure between the first and second rates. The approximate pre-charge pressure is determined based on the transition pressure. | 09-26-2013 |
20130253854 | HYDRAULIC ACCUMULATOR HEALTH DIAGNOSIS - A system to diagnose a health of a hydraulic accumulator is provided. The hydraulic accumulator includes a first fluid chamber, a second fluid chamber, and a separator. The hydraulic accumulator has an associated pre-charge pressure. The system further includes a pressure sensor, a fluid source, a data processor, and a comparator. The pressure sensor and the fluid source are connected to the first fluid chamber. The data processor is configured to determine a first and second rate of pressure changes, and a transition pressure between the first and second rates. The approximate pre-charge pressure is determined based on the transition pressure. The comparator is configured to compare at least one of the determined pre charge pressure and the frictional forces with a pre-determined threshold range of pre-charge pressure and the frictional forces associated with the hydraulic accumulator to diagnose the health of the hydraulic accumulator. | 09-26-2013 |
20130283777 | HYDRAULIC CONTROL SYSTEM HAVING ENERGY RECOVERY - A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a pump, a tank, and an actuator. The hydraulic control system may also have at least a first valve configured to control fluid flow between the pump, the tank, a first chamber of the actuator, and a second chamber of the actuator; a second valve fluidly disposed between the second chamber and the tank; and a third valve fluidly disposed between the first and second chambers. The hydraulic control system may further have a controller configured to selectively cause the second valve to block fluid flow from the second chamber of the actuator to the tank, and to selectively cause the third valve to fluidly communicate the first and second chambers of the actuator when the second valve blocks fluid flow from the second chamber of the actuator to the tank. | 10-31-2013 |
20130318955 | ELECTRO-HYDRAULIC SYSTEM FOR RECOVERING AND REUSING POTENTIAL ENERGY - A hydraulic system includes a hydraulic actuator, a pump configured to supply fluid to the hydraulic actuator, and a first accumulator fluidly connected to the hydraulic actuator. The first accumulator is configured to store fluid received from the hydraulic actuator. The hydraulic system also includes a motor drivingly connected to the pump and fluidly connected to the first accumulator. The motor is configured to receive the stored fluid from the first accumulator to drive the pump. The hydraulic system further includes a first discharge valve fluidly connected between the first accumulator and the hydraulic actuator. The first discharge valve is configured to supply the stored fluid from the first accumulator to the hydraulic actuator without the stored fluid from the first accumulator circulating through the pump. | 12-05-2013 |
20130340418 | Energy Storage Cylinder and Control System for a Moving Structural Member - An energy storage system is disclosed for use in a hydraulic system for moving a structural member such as a boom assembly. The system features at least one work cylinder and an additional energy storage cylinder that assists in raising and lowering functions by storing and withdrawing pressurized fluid from an accumulator. The pressurized fluid in the accumulator may be used for raising operations as well as digging and tamping operations. Further, the energy recovery features may be selectively disconnected during either a raising or lowering operation. | 12-26-2013 |
20140060018 | HYDRAULIC CONTROL SYSTEM - A hydraulic control system includes an implement movable to perform an excavation cycle having a plurality of segments, a variable displacement motor configured to swing the implement at a desired speed during the excavation cycle, and a pump configured to pressurize fluid directed to drive the motor. The system further includes an accumulator configured to selectively receive fluid discharged from the motor via a charge valve, and to discharge fluid to the motor via a discharge valve. The system includes a selector valve fluidly connected to the charge valve and the discharge valve. The system also includes a controller configured to vary displacement of the motor, resulting in the desired speed. | 03-06-2014 |
20140060023 | HYDRAULIC CONTROL SYSTEM HAVING SWING MOTOR ENERGY RECOVERY - A hydraulic control system is disclosed for use in a machine. The hydraulic control system may have a work tool, a motor configured to swing the work tool, a tank, a pump configured to draw fluid from the tank and pressurize the fluid, and a control valve operable to control fluid flow from the pump to the motor and from the motor to the tank via first and second chamber passages to affect motion of the motor. The hydraulic control system may also have an accumulator, and an accumulator circuit configured to selectively direct fluid discharged from the motor to the accumulator for storage and to direct stored fluid from the accumulator to the motor to assist the motor. The hydraulic control system may further have a selector valve configured to selectively connect a higher pressure one of the first and second chamber passages with the accumulator, and a single pressure relief valve disposed within the accumulator circuit and configured to relief pressure from opposing sides of the motor. | 03-06-2014 |
20140060024 | HYDRAULIC CONTROL SYSTEM HAVING SWING MOTOR RECOVERY - A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a tank, a pump, a swing motor, and at least one control valve configured to control fluid flow between the pump, the swing motor, and the tank. The hydraulic system may also have an accumulator configured to selectively receive pressurized fluid discharged from the swing motor and selectively supply pressurized fluid to the swing motor, at least one accumulator valve, and a controller. The controller may be configured to receive input indicative of a difference between desired and actual speeds of the swing motor, and determine if the swing motor is accelerating or decelerating based on the difference. The controller may also be configured to control the at least one accumulator valve to cause the accumulator to selectively receive or supply pressurized fluid only when the swing motor is accelerating or decelerating. | 03-06-2014 |
20140060025 | HYDRAULIC CONTROL SYSTEM HAVING ELECTRONIC FLOW LIMITING - A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a tank, a pump, an actuator, and a control valve configured to direct fluid from the pump to the actuator and from the actuator to the tank. The hydraulic control system may also have a pressure sensor to generate a first signal indicative of a pressure differential across the control valve, an operator input device to generate a second signal indicative of a desired movement of the actuator, and a controller. The controller may be configured to make a first determination of an opening amount of the control valve based on the second signal, and to make a second determination based on the first signal of whether the opening amount will result in overspeeding of the actuator. The controller may also be configured to reduce the opening amount based on the second determination. | 03-06-2014 |
20140060030 | HYDRAULIC ACCUMULATOR HEALTH MONITOR - A system and method to diagnose the operational health of a hydraulic accumulator are provided. The system can include a hydraulic accumulator selectively coupled to a hydraulic actuator, such as a swing motor. The accumulator can be charged by movement of the actuator. A pressure sensor can be associated with the accumulator to determine an accumulator pressure. A controller can be connected to the pressure sensor. The controller can determine a charge curve based on a relationship between an actuator operational parameter associated with the actuator movement and the accumulator pressure. The controller can compare the charge curve to a previously defined charge curve or range to determine an error between the charge curve and the previously defined charge curve or range. The degree of the error can be associated with the operational health of the accumulator, and if too large, the operator may be notified of the status. | 03-06-2014 |
20140060031 | HYDRAULIC CONTROL SYSTEM HAVING SWING ENERGY RECOVERY - A hydraulic control system for a machine is disclosed. The hydraulic control system may have a tank, a pump, and a fluid actuator. The hydraulic control system may further have an accumulator configured to selectively receive pressurized fluid discharged from the fluid actuator and selectively supply pressurized fluid to the fluid actuator. The hydraulic control system may also have a pressure sensor configured to generate a signal indicative of a pressure of the accumulator, a charge valve, a discharge valve, and a controller in communication with the control valve, the charge valve, and the discharge valve. The controller may be configured to detect stall of the fluid actuator, to make a comparison of the pressure of the accumulator with a threshold pressure, and to selectively move the charge valve to charge the accumulator or move the discharge valve to discharge the accumulator during the stall based on the comparison. | 03-06-2014 |
20140119867 | ENERGY RECOVERY SYSTEM HAVING INTEGRATED BOOM/SWING CIRCUITS - An energy recovery system for a machine is disclosed. The energy recovery system may have a boom circuit with at least a one linear actuator configured to move a work tool, and a boom accumulator configured to selectively collect pressurized fluid from the at least one linear actuator and to discharge pressurized fluid back to the at least one linear actuator. The energy recovery system may also have a swing circuit with a swing motor configured to move the work tool, and a swing accumulator configured to selectively collect pressurized fluid from the swing motor and discharge pressurized fluid back to the swing motor. The energy recovery system may further have a common accumulator passage fluidly connecting the boom accumulator and the swing accumulator. | 05-01-2014 |
20140119868 | ENERGY RECOVERY SYSTEM HAVING PEAK-SHAVING ACCUMULATOR - An energy recovery system for a machine is disclosed. The energy recovery system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, an actuator, and an actuator control valve movable to direct pressurized fluid from the pump to the actuator and from the actuator to the tank to move the actuator. The energy recovery system may also have a motor connected to selectively receive fluid discharged from the actuator and mechanically connected to the pump, and an accumulator configured to store fluid discharged from the motor and to direct stored fluid to the motor to drive the pump. | 05-01-2014 |
20140150415 | Energy Recovery Hydraulic System - A method and system for accumulating and using recovered hydraulic energy that includes a hydraulic actuator and a pump configured to supply pressurized fluid to the hydraulic actuator. An energy recovery system includes a hydraulic motor, a charge valve and an accumulator configured to store fluid from the hydraulic actuator. The charge valve is operatively connected between the hydraulic actuator and the accumulator and between the accumulator and the hydraulic motor and is configured to place the hydraulic actuator in fluid communication with the accumulator and to place the accumulator in fluid communication with the hydraulic motor. A directional valve is operatively connected between the pump and the hydraulic actuator. The directional valve is configured to place the pump in fluid communication with the hydraulic actuator and to direct the flow of hydraulic fluid exiting the hydraulic actuator to the charge valve in an energy recovery mode. | 06-05-2014 |
20140174064 | HYDRAULIC CONTROL SYSTEM FOR SWING MOTOR - A hydraulic control system for a machine is disclosed. The hydraulic control system includes a swing control valve coupled between the swing motor, the pump and the tank to selectively control a fluid flow between the pump and the swing motor. The hydraulic control system includes a first conduit coupled between a first port of the swing control valve and a first chamber port of the swing motor. Further, a second conduit is coupled between a second port of the swing control valve and a second chamber port of the swing motor. A first chamber valve and a second chamber valve coupled to the first conduit and the second conduit and movable between a first open position, a second open position and a closed position. A controller is configured to selectively move one of the first and second chamber valves to reduce the fluid flow between the swing motor and the tank such that the pressurized flow discharged from the swing motor is directed to an accumulator fluidly coupled to each of the first and second conduits. | 06-26-2014 |
20140174065 | HYDRAULIC CONTROL SYSTEM FOR SWING MOTOR - A hydraulic control system for a machine is disclosed. The hydraulic control system includes a swing control valve coupled between the swing motor, the pump and the tank to selectively control a fluid flow between the pump and the swing motor. The hydraulic control system includes a first conduit coupled between a first port of the swing control valve and a first chamber port of the swing motor. Further, a second conduit is coupled between a second port of the swing control valve and a second chamber port of the swing motor. A first chamber valve and a second chamber valve coupled to the first conduit and the second conduit. A controller is configured to selectively move one of the first and second chamber valves to reduce the fluid flow between the swing motor and the tank such that the pressurized flow discharged from the swing motor is directed to an accumulator fluidly coupled to each of the first and second conduits. | 06-26-2014 |
20140208728 | Method and Hydraulic Control System Having Swing Motor Energy Recovery - A hydraulic control system includes a swing control valve between a pump and a swing motor to control flow to/from the swing motor, and a selector valve between an accumulator and the swing motor to regulate fluid flow. A controller is configured to receive inputs indicative of the pressure differential between the accumulator and conduit between the pump and swing motor, and a swing motor command, calculate a target swing motor flow based on the swing motor command input, and modulate operation of the swing control valve and the selector valve to regulate a swing speed. | 07-31-2014 |
20140230420 | ENERGY RECOVERY SYSTEM FOR HYDRAULIC MACHINE - An energy recovery system is disclosed for use with a hydraulic machine. The energy recovery system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, an actuator, and an actuator control valve movable to direct pressurized fluid from the pump to the actuator and from the actuator to the tank to move the actuator. The energy recovery system may also have a motor mechanically connected to a rotary device and configured to selectively receive fluid discharged from the actuator, and at least one valve movable to selectively redirect fluid exiting the motor back to the actuator. | 08-21-2014 |
20140283915 | Hydraulic Control System Having Relief Flow Capture - A hydraulic circuit may be provided. The circuit may include: a pump to supply pressurized fluid to a circuit; a supply passageway coupled between the pump and the circuit; a relief flow passageway coupled between the supply passageway and a fluid reservoir; a relief flow capture circuit coupled to the relief flow passageway, the relief flow capture circuit including: a first valve configured to move from a closed position to an open position when a first pressure is detected; a second valve in fluid communication with the first valve, the second valve configured to move from a closed position to an open position when a second pressure is detected wherein the second pressure is lower than the first pressure; and an accumulator located between the first and second valves and in fluid communication with both the first and second valves, the accumulator configured to store fluid flowing through the first valve when the first pressure valve is in an open position, the accumulator further configured to outflow fluid through the second valve when the second valve is in an open position. | 09-25-2014 |
20140325972 | Hydraulic Hybrid Boom System Hydraulic Transformer - A hydraulic system includes a hydraulic actuator, an accumulator, an accumulator charge valve, and a hydraulic transformer fluidly connected between the accumulator charge valve and the accumulator. The hydraulic transformer includes a transformer motor mechanically coupled to a transformer pump. The accumulator charge valve is fluidly connected between the transformer motor and the hydraulic actuator. The transformer pump is sized to permit a maximum flow therethrough of no more than three-quarters of a flow permitted through the transformer motor. | 11-06-2014 |