Abstract: A hydraulic machine includes: a power source; an assist motor including comprising an inlet port and an outlet port and assisting a torque of the power source; a tank; a collection line which is connected to the inlet port and allows a fluid to flow to the inlet port; a first return line which is connected to the tank and allows the fluid to flow to the tank; a self-priming line which connects the first return line to the inlet port and allows the fluid to flow from the first return line to the inlet port; and an anti-cavitation line which connects the outlet port to the self-priming line and allows the fluid to flow from the outlet port to the self-priming line.

Abstract: A housing of brake device includes a first oil path, a second oil path that is adjacent to the first oil path in a first direction along an axial direction of the first oil path and has a larger cross-section orthogonal to the axial direction than the first oil path, a third oil path connected to the first oil path, and a fourth oil path connected to the second oil path. A throttle member of the brake device is anchored to the housing by being press-fitted into the first oil path. The third oil path connects the fourth oil path through the throttle. When the throttle member moves in the first direction by releasing the press-fitting, the third oil path connects the fourth oil path through a gap between an inner circumferential surface forming the second oil path and an outer circumferential surface of the throttle member.

Abstract: This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism and a boom cylinder The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to starting and stopping of the rotary mechanism. A control system configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, and a boom control valve configured to control the boom cylinder through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

Abstract: Presented herein are systems and methods for attenuating certain pulsations in a hydraulic system comprising a pump and a hydraulic actuator. In certain aspects, an accumulator comprising an internal volume that is divided into a working chamber and a contained chamber may be utilized to at least partially attenuate propagation of certain pulsations in the system. The working chamber may be fluidically coupled to the pump via a first flow path and fluidically coupled to a chamber of the actuator via a second flow path. The system may be designed such that a first inertance of the first flow path is greater than a second inertance of the second flow path. Additionally or alternatively, the system may be designed such that a resonance associated with the first inertance and a compliance of the accumulator may occur at a resonance frequency of less than 90 Hz.

Abstract: A work machine including: a hydraulic cylinder 20 configured to drive a work implement 3; a control valve 22 configured to connect a delivery line of a hydraulic pump 21 switchingly to a bottom fluid chamber and a rod fluid chamber of the hydraulic cylinder 20 and a tank; a pilot pump 23 configured to output a pilot pressure to drive the control valve 22; an engine 24 configured to drive the hydraulic pump 21 and the pilot pump 23; and an accumulator 26 configured to accumulate a return hydraulic fluid from the hydraulic cylinder 20 is provided with: a bypass line 41 configured to connect the bottom fluid chamber of the hydraulic cylinder 20 and a delivery line 21a of the hydraulic pump 21 by bypassing the control valve 22 and be provided with the accumulator 26 thereon; a pressure-accumulation control valve 27 provided between the bottom fluid chamber of the hydraulic cylinder 20 and the accumulator 26; a release control valve 28 provided between the accumulator 26 and the delivery line 21a; and a hydraulic

Abstract: A double-loop control system with a single hydraulic motor relates to a technical field of hydraulic transmission control, including a hydraulic motor (1), a positive control loop (2), a negative control loop (3), a hydraulic pump (4), an accumulator (5), and an oil tank, wherein the hydraulic motor (1) adopts a unique thrust structure with four inlet/outlet ports; the positive control loop (2) and the negative control loop (3) independently control the hydraulic motor (1), wherein the positive control loop (2) and the negative control loop (3) drive together or only one drives; or braking kinetic energy and potential energy of loads are stored in the accumulator (5) for energy recovery. The present invention uses only one hydraulic motor for satisfying different work conditions and different load driving requirements with advantages such as simple structure, high system reliability and high energy efficiency.

Abstract: Disclosed are power machines and lift arm suspension or ride control systems for use thereon. A lift arm assembly is pivotally coupled to a frame of the power machine and is capable of being raised and lowered. A selectively activated lift arm suspension system is operably coupled to the lift arm assembly. A controller is coupled to the suspension system and configured to determine whether the lift arm assembly has moved more than a threshold amount. The controller deactivates the lift arm suspension system in response to determining that the lift arm assembly has moved more than the threshold amount.

Abstract: Control fluid power apparatus and related methods are disclosed. An example control fluid power apparatus includes a first housing having a first piston defining a first chamber and a second chamber, where the first chamber receives a control fluid and the second chamber receives a process fluid from a process system. The first chamber is oriented above the second chamber when the control fluid power apparatus is coupled to a control valve assembly. A second housing has a second piston defining a third chamber and a fourth chamber, where the third chamber receives the control fluid and the second chamber receives the process fluid. The third chamber is oriented above the fourth chamber when the control fluid power apparatus is coupled to the control valve assembly.

Abstract: A hydraulic transmission circuit is provided having at least two elementary hydraulic motors, each having a secondary enclosure and a main duct for fluid feed and a secondary enclosure and a main duct for fluid discharge. A fluid distributor distributes fluid from the main ducts to the elementary motors via the secondary enclosures. A control system controls the elementary motors. Valves connecting the fluid distributor to the secondary enclosures of the first motor put a secondary enclosure into communication with a main duct independent of an operating mode of any other elementary motor.

Abstract: An object is to reduce a load acting on an engine upon starting up the engine such that the engine can be quickly started up to reliably feed pressure oil from a hydraulic pump to an accumulator.

Abstract: A regenerative hydraulic pump that allows for efficient operation of a hydraulic system under high pressure/low flow conditions that comprises a crankshaft providing a rotating inertial mass, and a regenerative hydraulic pump cylinder that comprises a pump cylinder housing, a pump piston mechanically connected to the crankshaft; and a compliant pressure chamber that stores a portion of the energy extracted by the pump piston during a pumping stroke for release back to the pump piston and to the crankshaft during a regenerative back stroke.

Abstract: A holding element, in particular for a hydraulic unit of a slip-controllable block vehicle braking system, includes at least one side wall which, at one end, has a receptacle for holding the hydraulic unit. The holding element further includes at least one fastening element for fastening the holding element to a support part, wherein the holding element is at least substantially designed as a single piece. The holding element is manufactured at least substantially from plastic and the side wall is provided with at least one stiffening rib which runs in a radial or radiated manner with respect to the receptacle.

Abstract: The present application relates to a powertrain control system (1) for a motor vehicle. The vehicle has an internal combustion engine (5) coupled to a transmission (9). The transmission (9) is operable in a high range and a low range. The powertrain control system (1) has a stop/start controller (11) for issuing an engine stop request signal when one or more conditions have been met. An inhibitor (15) is also provided for inhibiting operation of the stop/start controller (11) when the low range is selected. The application also relates to a method of operating a motor vehicle power-train.

Abstract: A shut off valve is configured to shut off flow from the high pressure fluid line to the high pressure accumulator in a series hydraulic hybrid vehicle in order to quickly raise system pressure in the high pressure fluid line and enable additional torque output from the hydraulic motor for vehicle propulsion. A pressure relief valve is further provided to vent excess flow from the high pressure line to the high pressure accumulator as needed to avoid exceeding a maximum desired system pressure in the high pressure fluid line, thereby providing for safe and efficient hydrostatic operation in the vehicle.

Abstract: A hybrid drivetrain for a motor vehicle includes an automated mechanical transmission (AMT) having an output shaft. The drivetrain includes an alternative energy source including a motor and an energy storage unit and two torque transfer arrangements. The first transfer arrangement is separate from engageable gear sets of the AMT for transferring torque from the output shaft to a motor when the energy storage unit is being charged and for transferring torque from the motor to the output shaft when the energy storage unit is being discharged. Additionally, an alternative energy source clutch for selectively coupling the first torque transfer arrangement to the output shaft is included. The second torque transfer arrangement is for transferring torque from the output shaft to a driven axle of the motor vehicle. At least one of the first and second torque transfer arrangements has different first and second torque transfer ratios.

Abstract: To lower the fuel consumption of a vehicle having a pneumatic brake system during operation of the vehicle by utilizing existing components to their full capacity, thus contributing to energy conservation, a method and device for controlling pressure is provided, wherein modes of compressed air expansion are provided. In a second compressed-air expansion mode, compressed air is channeled from a second compressed-air storage container to the compression chamber of the air compressor during expansion phases of the air compressor. In a third compressed-air expansion mode, compressed air is channeled from a third compressed-air storage container to the compression chamber of the air compressor during expansion phases of the air compressor.

Abstract: A hydrostatic drive system has a motor-driven hydraulic pump (1) connected to at least one hydraulic drive unit (7) by a first working line (19) and a second working line (21) forming a hydraulic circuit. The drive unit is connected to a gear set (1, 3). A first hydraulic accumulator (53) for accumulating pressure energy can be connected to one of the working lines (19, 21). A second hydraulic accumulator (55) can be connected to the other working line (19, 21). A valve device (V1, V2) permits the segment (23, 25) of each working line (19 or 21) extending to the drive unit (7) to be separated to separate an accumulator part (33) from the part of the circuit with the hydraulic pump (13). The accumulator part includes the hydraulic accumulators (53, 55) and at least one drive unit.

Abstract: A hydraulic hybrid safety system with an over-center bent-axis rotary pump/motor, a yoke and a calibrated orifice. The yoke has a zero yoke angle and a plurality of non-zero yoke angles. In addition, the pump/motor has zero torque when the yoke angle is at the zero yoke angle and non-zero torque when the yoke is at a non-zero yoke angle. The system also has at least one accumulator and at least one hydraulic line. The at least one accumulator is configured to provide hydraulic pressure and rotate the yoke via the at least one hydraulic line. The calibrated orifice is located within the at least one hydraulic line and limits the rotational speed of the yoke to a predetermined maximum value.

Abstract: An object is to reduce a load acting on an engine upon starting up the engine such that the engine can be quickly started up to reliably feed pressure oil from a hydraulic pump to an accumulator.

Abstract: 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.

Abstract: An oil level control device in a main tank of a supply circuit, the supply circuit comprising a main tank, a first pump which, in aspiration, is connected to the main tank, a main hydraulic circuit which is connected in inlet to the delivery of a charge pump and in outlet is connected to the main tank, a first auxiliary conduit, an auxiliary tank which receives oil from the first auxiliary conduit and which in discharge is placed in communication with the main tank. At least a control valve predisposed to control sending of oil from the first auxiliary conduit to the auxiliary tank or from the auxiliary tank to the main tank.

Abstract: A pneumatic system with multiple air reservoirs is connected to the bellows of a load elevator. A plurality of valves enables the optional pneumatic connection of different combinations of reservoirs so as to change the range of operation of the elevator to meet the self-adjusting weight requirements of a particular job at hand. In the preferred embodiment, the air actuator is pneumatically connected to a main air reservoir, which in turn can optionally be coupled in series with one or two additional reservoirs of different capacities. As a result of this configuration of its pneumatic system, the elevator can be switched between and operated at three different load levels, at the convenience of the operator, without changing the amount of air in the system.

Abstract: 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.

Abstract: A hydraulic fluid system for a mobile machine includes a closed loop hydraulic fan circuit. The hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan driven by the motor. The hydraulic fan circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a first accumulator selectively fluidly connected to at least one of the supply and return passages via a charge valve. The hydraulic fluid system also includes at least one open loop hydraulic circuit fluidly connected to the first accumulator.

Abstract: A hydraulic actuator assembly includes an actuator, a first sink subsystem in fluid communication with an upper working chamber of the actuator, a second sink subsystem in fluid communication with a lower working chamber of the actuator and a source subsystem in fluid communication with both the upper and lower working chambers of the actuator. A low pressure accumulator is in fluid communication with the upper and lower working chambers, the first and second sink subsystems and source subsystem. A high pressure accumulator is in fluid communication with the first and second sink subsystems and the source subsystem. The hydraulic actuator assembly can generate passive or active forces with or without energy recuperation.

Abstract: A hydraulic-electrical transducer, a transducer arrangement having a plurality of such transducers, and a method for driving a hydraulic-electrical transducer includes driving two adjustable hydraulic machines of each transducer in such a way that a predetermined damping pressure is set in a pressure line of a pump of a PTO (Power Take Off device) depending on the mechanical power which is input into the PTO.

Abstract: 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.

Abstract: The invention relates to methods and systems for the storage and recovery of energy using open-air hydraulic-pneumatic accumulator and intensifier arrangements that combine at least one accumulator and at least one intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits.

Abstract: A telescopic unit for telescoping means arranged on machines, comprising at least one telescopic hydraulic cylinder and at least one piston arranged axially movable in the cylinder chamber of the telescopic hydraulic cylinder and connected to a piston rod, the bottom side or the piston rod side of the telescopic hydraulic cylinder being configured fixable to a bearing allocated to the machine, and at least one additional hydraulic system being allocated to the free end of the telescopic unit.

Abstract: 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.

Abstract: A system for reversible storage of energy, the system comprising: means for generating energy; first conversion means for converting the energy into stored energy by means of low ratio (3.2:1 or less) high pressure (200 bar minimum) compression of gas; and second conversion means for converting the stored energy by expansion or reversal of the first process into usable energy.

Abstract: An expandable accumulator and reservoir assembly includes a housing defining an interior chamber configured to contain a working fluid therein. An expandable accumulator is positioned at least partially within the housing. The expandable accumulator includes at least one flexible member configured to be at least partially immersed in the working fluid contained within the interior chamber. A rigid support member is positioned in the interior chamber and outside of the expandable accumulator. The rigid support member has at least one aperture to allow passage of the working fluid. An additional flexible member is positioned outside the rigid support member and has perimeter portions sealed to the outside of the rigid support member. The additional flexible member defines a flexible boundary between a primary reservoir inside the additional flexible member and a separate secondary reservoir outside the additional flexible member.

Abstract: A hydraulic oscillating motor which has at least two working chambers which are coupled via pressure lines to a device for pressure compensation. A first working chamber is connected to a first pressure line and a second working chamber is connected to a second pressure line. The motor further has a device for pressure compensation with a first compensating cylinder and a second compensating cylinder. Each of the compensating cylinders has in each case one compensating volume and in each case one elastic force store for delimiting the respective compensating volume. The compensating volume of the first compensating cylinder is connected to the first pressure line, and the compensating volume of the second compensating cylinder is connected to the second pressure line.

Abstract: 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.

Abstract: A hydraulic circuit is provided. The hydraulic circuit includes a primary pump, a displacement actuator, a charge pump, a direction control valve, and a pressure control valve. The displacement actuator is associated with the primary pump. The charge pump is configured to generate a flow of a pilot fluid. The direction control valve is configured to control the flow of the pilot fluid to the displacement actuator to affect a movement direction of the displacement actuator. The pressure control valve is configured to control a pressure of the pilot fluid to affect a movement amount of the displacement actuator. Further, the hydraulic circuit includes a controller. The controller is configured to control the direction and the pressure control valves to adjust a displacement of the primary pump based at least on one of a sensed engine parameter or a mode of operation of the primary pump.

Abstract: A method is provided for controlling a hydraulic system having at least an implement pump, a fan-steering-braking (FSB) pump, a valve assembly, a fan drive system and one or more accumulators. The method may determine an operational state of a power source associated with the hydraulic system, actuate one or more valves of the valve assembly such that the FSB pump charges the accumulators and operates at least the fan drive system if the power source is operating at less than maximum power, and actuate one or more valves of the valve assembly such that the accumulators operate at least the fan drive system and such that the FSB pump supplements the implement pump as needed if the power source is operating at maximum power.

Abstract: Micro-hydraulic supply and storage units capable of recovering waste energy and storing energy for later use, such as for operating hydraulic valve actuation and high pressure fuel injection systems. The system includes a sump, a pump motor, an accumulator and a supply rail. Valving is provided to couple the outlet of the pump motor to the accumulator to fill the accumulator with what otherwise would be waste energy, such as when a vehicle is using its engine for braking, directing the output of the pump motor to a supply rail to maintain the pressure in the supply rail, and directing the output of the pump to a sump. The valving also allows directing an outlet of the accumulator to an inlet of the pump motor for recover of the energy in the accumulator. Other aspects of the invention are disclosed.

Abstract: A hybrid drive system in a vehicle includes a prime mover, a starting device connected to the prime mover, and a transmission having a transmission input shaft connected to the starting device. A pump/motor is functionally interconnected between the starting device and the transmission. A first accumulator is in fluid communication with the motor/pump for storing a hydraulic fluid under pressure and a second accumulator is in fluid communication with the pump/motor for storing hydraulic fluid discharged from the first accumulator. Discharge of the first accumulator drives the pump/motor to provide a drive torque to the transmission input shaft and to provide a drive torque to the prime mover for starting the prime mover.

Abstract: An energy storage system that converts irregular power to controlled power by a hydraulic power converter that utilizes the irregular power to pump hydraulic fluid, stores at least a part of the pumped hydraulic fluid in a pressurized accumulator cluster, and provides controlled power by a hydraulic motor operated by pressurized hydraulic fluid from the accumulator cluster, according to a specified power demand. The operation of the hydraulic power converter may be controlled electrically and mechanically, and the hydraulic power converter may be integrated in a vehicle, to maintain an optimal operation range of the engine, or in an energy production device, for generating controlled power from the irregular output of the device.

Abstract: A brake device can prevent deterioration of braking force by applying a predetermined pressure in the drive hydraulic pressure chamber even when an electric system failure occurs. The brake device includes a stroke simulator portion, regulator, a first passage connecting the accumulator and the high pressure port of the regulator, a second passage connecting the reservoir tank and the low pressure port of the regulator, a third passage connecting the stroke simulator portion and the pilot pressure input port of the regulator, a fourth passage connecting the drive hydraulic pressure chamber and the output port of the regulator and a fifth passage connecting the accumulator and the drive hydraulic pressure chamber bypassing the high pressure port. The normally open type pressure decrease control valve is provided in the second passage or in the fourth passage whereas the normally closed pressure increase control valve is provided in the fifth passage.

Abstract: The invention relates to a hydraulic unit of a vehicle hydraulic brake system having a hydraulic block, a storage unit, and a holding unit. The storage unit is inserted into the hydraulic block, and the holding unit is adjusted for holding the hydraulic block locally fixed to an associated vehicle. The storage unit is constructed with a holding surface which forms a section of the outer side of the hydraulic unit, and the holding unit engages with the holding surface of the storage unit in order to hold the hydraulic block locally fixed above the storage unit. Furthermore, the invention also relates to a storage unit where one outer surface of the storage unit which forms an outer side of the hydraulic unit is constructed as a holding surface for attaching the hydraulic block in the vehicle.

Abstract: 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.

Abstract: A hydraulic pump includes a hydraulic cylinder assembly comprising a cylinder sealed by an upper head and a lower head and carrying a piston which divides the hydraulic cylinder assembly into an upper chamber and a lower chamber. A load is connected to the piston and urges it toward the lower head. A conduit connects a reversible hydraulic pump assembly in fluid flow communication with a pressurized supply of hydraulic fluid and the lower chamber for counterbalancing the load. A control system is operably associated with the reversible hydraulic pump assembly to cause hydraulic fluid to flow back and forth between the lower chamber of the hydraulic cylinder assembly and the pressurized supply of hydraulic fluid. A system is also provided to counteract leakage in the pump by adding hydraulic fluid makeup on an as needed and controlled basis.

Abstract: Apparatus (1) for storing energy includes a high pressure storage vessel (10) for receiving high pressure gas, the high pressure storage vessel (10) including a high pressure heat store including a first chamber housing a first gas-permeable heat storage structure (14); and a low pressure storage vessel (11,12) for receiving low pressure gas, the low pressure storage vessel (11,12) including a low pressure heat store including a second chamber housing a second gas-permeable heat storage structure (16,18. The first heat storage structure (14) has a mean surface area per unit volume which is higher than a mean surface area per unit volume of the second heat storage structure (16,18).

Abstract: A hydraulic fluid system for a mobile machine includes a closed loop hydraulic fan circuit. The hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan driven by the motor. The hydraulic fan circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a first accumulator selectively fluidly connected to at least one of the supply and return passages via a charge valve. The hydraulic fluid system also includes at least one open loop hydraulic circuit fluidly connected to the first accumulator.

Abstract: The present invention relates to a hydraulic drive system having a pressure-regulated hydraulic pump for the provision of a system pressure and having a secondarily regulated hydraulic motor. In accordance with the invention, a control is provided which sets the desired system pressure during operation in dependence on an operating parameter of the hydraulic motor.

Abstract: A machine is provided with a first work arm, at least one first cylinder having a first lift chamber configured for receiving pressurized fluid so as to lift the first work arm, and a first accumulator associated with the first lift chamber of the first cylinder. The machine further includes a second work arm, at least one second cylinder having a second lift chamber configured for receiving pressurized fluid so as to lift the second work arm, and a second accumulator associated with the second lift chamber of the second cylinder. A control arrangement is provided for selectively fluidly connecting one or both of the first and second accumulators with the associated first and second lift chambers.

Abstract: Systems and methods for operating a hydraulically actuated device/system are described herein. For example, systems and methods for the compression and/or expansion of gas can include at least one pressure vessel defining an interior region for retaining at least one of a volume of liquid or a volume of gas and an actuator coupled to and in fluid communication with the pressure vessel. The actuator can have a first mode of operation in which a volume of liquid disposed within the pressure vessel is moved to compress and move gas out of the pressure vessel. The actuator can have a second mode of operation in which a volume of liquid disposed within the pressure vessel is moved by an expanding gas entering the pressure vessel. The system can further include a heat transfer device configured to transfer heat to or from the at least one of a volume of liquid or a volume of gas retained by the pressure vessel.

Abstract: A hydrostatic driveline for a vehicle, a method for minimizing a fuel consumption rate of the vehicle, and a method for tracking an optimal state of charge function for a hydrostatic accumulator are provided. The driveline includes a power source, a drive axle, a first fluid accumulator, a second fluid accumulator, an auxiliary circuit including a first pump drivingly engaged with the power source, and a drive circuit including a second pump drivingly engaged with the power source, a motor drivingly engaged with the drive axle, and a directional valve. The second pump is in fluid communication with the directional valve and the directional valve in fluid communication with the first fluid accumulator and the second fluid accumulator. The directional valve may be selectively controlled to direct fluid from the second pump and the motor to the first fluid accumulator and the second fluid accumulator.

Abstract: A hydrostatic transmission in the shape of a shaft/rotor comprising two hydraulic pumps/motors with adjustable displacement connected in a closed hydraulic system. The displacement of the pumps/motors is adjusted by adjusting the angle of swash plates of the pumps/motors. The control and regulation of the angle of the swash plates is done by transferring a signal by two separate pulse width modulated DC fed pulse trains. The hydrostatic transmission includes oil accumulators connected to the hydraulic pumps/motors.