Abstract: A hydraulic excavator drive system includes: a first pump that supplies hydraulic oil to a boom cylinder via a boom control valve, and supplies the hydraulic oil to a bucket cylinder via a first bucket control valve; a second pump that supplies the hydraulic oil to an arm cylinder via an arm control valve; a third pump that supplies the hydraulic oil to a slewing motor via a slewing control valve, and supplies the hydraulic oil to the bucket cylinder via a second bucket control valve; and a controller that moves one of the first bucket control valve and the second bucket control valve when a bucket excavating operation or a bucket dumping operation is performed concurrently with another operation, and moves both the first bucket control valve and the second bucket control valve when a bucket excavating operation is performed alone.

Abstract: An object of the present invention is to provide a construction machine capable of suppressing lugging down of an engine irrespective of contents of operation of an operator and the load state of a hydraulic actuator.

Abstract: There is provided a method of transporting fluid produced from a fluid source having a source pressure to a fluid destination having a destination pressure rating. The method has the steps of determining a compressor power requirement based on the destination pressure rating and an estimated rate of flow. A compressor having a power rating that is less than the determined compressor power requirement is provided. An input of the compressor is connected to the fluid source and connecting an output of the compressor to the fluid destination. The compressor is operated in a high volume mode for a first portion of a compression stroke path and in a low volume move for a remainder of the compression stroke path such that the compressor simulates the output from a compressor with higher power rating.

Abstract: A high pressure axial piston pump displaces high pressure, high volume fluid into a 1994-2003 7.3 liter power stroke or T444E International engine. A pump housing forms a central borehole, an intake port, and two discharge ports angled about 122 degrees from each other and in fluid communication with engine. A drive shaft rotates a cylinder block about an axis of rotation. A cam is tilted at an angle relative to axis of rotation. Multiple pistons, having a cam end and a block end, reciprocate through cylinder block. The cam end is constrained to follow surface of cam. When pistons move proximally to tilted cam, the block end restricts intake of fluid, and cam end enables discharge of fluid. When pistons move distally from tilted cam, the block end enables intake of fluid, and cam end restricts passage through discharge ports. The pump is fabricated from billet aluminum material.

Abstract: A system for supplying a turbine engine with fluid includes a first low-pressure pump, a downstream hydraulic resistance and a high-pressure volumetric pump located between the first low-pressure pump and the downstream hydraulic resistance. The downstream hydraulic resistance includes at least one element selected among a fluid proportioning unit, a filter, a flow meter, an exchanger, a cut-off valve and an injection system. The supply system includes a second low-pressure pump and a supply variator configured such as to vary the flow of fluid supplied to the second low-pressure pump, the second low-pressure pump and the supply variator being located parallel to the first low-pressure pump.

Abstract: A liquid feeding apparatus has a primary side pump and a secondary side pump, and an outlet part of the primary side pump and an inlet part of the secondary side pump are connected to each other via a check valve. A temporary side pump pressure sensor for detecting the pressure inside the pump chamber of the primary side pump and a secondary side pressure sensor for detecting the pressure inside the pump chamber of the secondary side pump are provided. The signal of the primary side pressure sensor and the signal of the secondary side pressure sensor are acquired after the suction operation of the primary side pump is terminated and before the discharge operation of the secondary side pump is terminated.

Abstract: A pump volume control apparatus includes: a tilting piston; a pump volume switching valve configured to adjust a tilt driving pressure by a movement of a spool; a flow rate control spring configured to bias the spool in accordance with a tilt angle; a horsepower control piston configured to move in accordance with a pump discharge pressure; and a horsepower control spring configured to bias the horsepower control piston in accordance with the tilt angle. The tilt driving pressure is adjusted by means of the movement of the spool in accordance with a force acting on the spool in response to a flow rate controlling signal pressure in a flow rate controlled state, and is adjusted by means of the movement of the spool in accordance with a force acting on the horsepower control piston in response to the pump discharge pressure in a horsepower controlled state.

Abstract: A tilting angle control device includes pressure sensors. Each of the pressure sensors outputs to a control unit a pressure command signal corresponding to an operation amount. The control unit outputs to an electromagnetic proportional control valve a pressure control signal corresponding to the pressure command signal, and the electromagnetic proportional control valve outputs to a tilt adjustment mechanism pilot pressure corresponding to the pressure control signal. The tilt adjustment mechanism adjusts a tilting angle of a variable displacement pump such that the tilting angle becomes an angle corresponding to the pilot pressure. A pilot pressure sensor detects the pilot pressure to output a pressure feedback signal to the control unit. The control unit calculates the pressure control signal based on the pressure feedback signal and the pressure command signal and performs feedback control of the pilot pressure.

Abstract: It is an object of the present invention to accurately detect the absorption torque of the other of two hydraulic pumps by a purely hydraulic structure and feed the absorption torque to one of the two hydraulic pumps, thereby to accurately perform a total torque control, effectively utilize a rated output torque of a prime mover, and enhance mountability.

Abstract: A brake booster device for a braking system of a vehicle includes: a booster body to which a brake-boosting force is exertable by an actuator device; a first piston rod component to which the brake-boosting force is at least partially transmittable via a first contact with the booster body, the first piston rod component contacting the booster body at a first contact surface such that the first piston rod component is at least partially adjustable; and a second piston rod component to which the brake-boosting force is at least partially transmittable via a second contact with the booster body, the second piston rod component contacting the booster body at a second contact surface such that the second piston rod component is adjustable together with the first piston rod component.

Abstract: Systems and methods relating to a plural in-series pumped liquid refrigerant trim evaporator cycle are described. The cooling systems include a first evaporator coil in thermal communication with an air intake flow to a heat load, and a first liquid refrigerant distribution unit in thermal communication with the first evaporator coil. The cooling systems further include a second evaporator coil disposed in series with the first evaporator coil in the air intake flow and in thermal communication with the air intake flow, and a second liquid refrigerant distribution unit in thermal communication with the second evaporator coil. A trim compression cycle of the second liquid refrigerant distribution unit is configured to further cool the air intake flow through the second evaporator coil when the temperature of the first fluid flowing out of the main compressor of the second liquid refrigerant distribution unit exceeds a predetermined threshold temperature.

Abstract: The present invention relates to a method of operating a fluid-working machine wherein the volume of working fluid displaced each cycle is selectable and wherein the volume of working fluid displaced by a first working chamber takes into account the suitability of the working chamber to displace fluid. The invention extends in further aspects to power absorbing structures such as renewable energy devices comprising such fluid working machines. The invention allows the operation of fluid working machines and power absorbing structures which are more long lived.

Abstract: Method for detecting a fault condition in a vehicular hydraulic circuit during a drive cycle using an electric pump includes monitoring an actual pump torque and monitoring a desired pump torque. A current confidence factor is determined based on the actual pump torque and the desired pump torque. An average confidence factor is iteratively calculated based on the current confidence factor and previously determined confidence factors. The average confidence factor is compared to a fault condition threshold. An absence of the fault condition in the hydraulic circuit is detected when the average confidence factor is at least the fault condition threshold, and a presence of the fault condition in the hydraulic circuit is detected when the average confidence factor is less than the fault condition threshold.

Abstract: A method for controlling a variable displacement pump by calculation by a controller using a closed-center-type directional control valve, the method allowing effective utilization of the variable displacement pump while avoiding the risk of engine stall is provided. The method includes determining a first virtual discharge pressure and a second virtual discharge pressure. The method includes controlling the variable displacement pump based on a smaller value of the first virtual discharge pressure and the second virtual discharge pressure.

Abstract: The invention provides a liquid treatment apparatus such as a reverse osmosis apparatus wherein a portion of an inlet liquid permeates through a filter or a membrane e.g. to provide freshwater from saltwater. The apparatus comprises a pump which provides the necessary pressure of the liquid to drive the permeation process, and a recovery unit which transfers pressure of a residue quid to the inlet liquid. The pump and the recovery unit are driven at synchronous and variable speed to control the output and thereby e.g. to adjust for fouling of the filter or membrane. The invention further provides methods of controlling the synchronous speed, e.g. based on a pressure or based on the consumption of the produced liquid.

Abstract: In drive control of an operating machine configured to drive a structure by a hydraulic motor configured to be driven by operating oil supplied from a hydraulic pump an electric motor configured to cooperate with the hydraulic motor, a speed command generated based on a manipulation amount of a remote control valve configured to determine an operation amount of the structure is subjected to speed feedback control performed based on the actual rotation speed of the hydraulic motor and pressure difference feedback control performed based on an operating oil pressure difference between a suction port and discharge port of the hydraulic motor. With this, a tilting angle command is generated such that the operating oil, the amount of which is necessary at the actual rotation speed of the hydraulic motor, is ejected, and the tilting angle of the hydraulic pump is controlled.

Abstract: An auxiliary device for a hydraulic brake assembly used on a two-wheel vehicle includes a body and a transmission device. The body has four cylinders respectively connected to the left and right brake lever hoses, and front and rear wheel brake hoses. By the operation of the transmission device, the front and the rear wheels are braked by either pulling the left brake lever or the right brake lever. The front wheel brake unit and the rear wheel brake unit are simultaneously activated by pulling either the left brake lever or the right break lever. The front wheel is braked right after the rear wheel is braked, and the braking force applied to the rear wheel is larger than that to the front wheel.

Abstract: A fuel metering system for supplying fuel to load includes a variable displacement piston pump having an adjustable hanger that is movable to a plurality of positions. The variable displacement piston pump is configured to receive a drive torque and, upon receipt of the drive torque, to supply fuel to the plurality of loads at a flow rate dependent on the position of the adjustable hanger. A hanger actuator is coupled to receive hanger position commands and is operable, in response thereto, to move the adjustable hanger to the commanded position.

Abstract: A method for warming up a vacuum pump arrangement having a booster pump and a backing pump downstream of the booster pump for evacuating a process chamber includes setting the booster pump at a first speed higher than an idle speed of the booster pump when the same is in an idle mode; and controlling a backing pressure at an outlet of the booster pump within a range from 0.1 mbar to 10 mbar at least for a period of time from when the vacuum pump arrangement is activated from the idle mode to when the booster pump reaches a temperature equal to or exceeding a first predetermined threshold value. Such method is implemented in system where a controlled is configured to carry out the above-motioned actions.

Abstract: A unified variable displacement pump having a housing which includes a fluid pump and a vacuum pump. A portion of the housing is part of the fluid pump, and a portion of the housing is part of the vacuum pump. A shaft extends through the fluid pump and the vacuum pump. A vacuum pump rotor is formed as part of the shaft, and a vane pump rotor is mounted to the shaft such that when the shaft rotates, the vacuum pump rotor and the vane pump rotor rotate, causing the fluid pump to pump fluid and the vacuum pump to generate a vacuum. The vacuum pump and fluid pump are combined into a single component driven by a single shaft.

Abstract: Pumping systems and methods for delivering a plurality of different pumpable materials serially at a location at substantially the same flow rate includes a plurality of diaphragm pumps, wherein each diaphragm pump has a first chamber for receiving a hydraulic fluid from a first and/or second hydraulic fluid source and a second chamber for receiving a material to be pumped from one of a plurality of pumpable material sources. A sensor is provided for detecting the pressure of the hydraulic fluid in each of the first chambers of the plurality of diaphragm pumps and is operable to activate the source of hydraulic fluid to ensure that the hydraulic fluid in each of the first chambers of the plurality of diaphragm pumps has an equivalent pressure.

Abstract: A method and apparatus for controlling discharge pressure and pump displacement of a plurality of variable displacement hydraulic pumps having connected discharge ports is provided. Each pump includes a swashplate and a control valve for controlling an angle of inclination of the swashplate. A desired first pump displacement control law is determined for a first pump and determined a desired second pump discharge pressure control law for a second pump. The first control law is used to determine a first intermediate control variable. The second control law is used to determine a second intermediate control variable. The control of the first and second pumps are combined using the first and second intermediate control variables. A desired first control valve setting for the control valve of the first pump is determined using the combined first and second intermediate control variables and the first control law.

Abstract: A pump system for producing fluids from a reservoir using a wellbore having a vertical section with a casing defining an annulus, a transitional section and a horizontal section, and a production tubing having a vertical section and a horizontal section, wherein the system includes a completion with an isolation device in the annulus near the bottom of the vertical section, a gas/liquid separator for receiving produced fluids from the horizontal section, and a vertical lift pump; a continuous flow path from the terminus of the production tubing to the vertical section; a plurality of horizontal pumps in the horizontal section, each having an intake exposed to the reservoir and an outlet in the continuous flow path. The horizontal length of the production tubing is closed to the reservoir except through the horizontal pumps.

Abstract: A control arm assembly connected with a hydraulic pump allows for the adjustment of pump displacement by turning a threaded adjustment rod clockwise or counter-clockwise to move a half nut connected with a control rod vertically up or down in a slot of an arm to the desired set point. The half nut has a partial thread that engages the thread of the adjustment rod to control the vertical movement. The design allows for the positive repeatable finite adjustment of the half nut with minimal backlash that reduces the difficulty of the setting process in labor and assembly time. Once the desired set point has been met the adjustment rod is clamped tight to the second arm by tightening the nut against the notch to lock up the assembly to prevent any movement.

Abstract: A fluid ejection device includes a pulse generation unit that changes the volume of a fluid chamber using a volume changing section to eject pulsating flow; a fluid supply unit including a pump chamber and a pump chamber volume changing section that changes the volume of the pump chamber to supply the fluid to the pulse generation unit; a drive control unit that inputs a pulsating flow drive signal for driving the pump chamber volume changing section and inputs a fluid supply drive signal for driving the fluid supply unit; and an operation command input unit that inputs an operation command to the drive control unit, wherein the fluid supply drive signal and the pulsating flow drive signal are input in conjunction with the input of the operation command.

Abstract: A hydraulic system for a vehicle powertrain includes a module including a clutch, an electric machine and a first sump, a transmission including a line pressure source and a second sump, and a pump that supplies fluid from the first sump to the line pressure source when the source of line pressure is unavailable, and supplies fluid from the first sump to the second sump when fluid volume in the second sump is low.

Abstract: The invention relates to a wind turbine being provided with a fluid displacement means for ensuring a certain increased pumping capacity at a certain reduced rotational speed of the main shaft of the rotor and thus of a drive shaft from a gear box of the wind turbine. The invention also relates to a wind turbine being provided with fluid displacement means for ensuring a certain increased pumping capacity at a certain increased rotational speed of the main shaft of the rotor and thus of a drive shaft from a gear box of the wind turbine. The means may be mechanical, hydraulic, pneumatic or electrical. Additionally, the invention relates to a method for operating a wind turbine being provided with such fluid displacement means.

Abstract: A method of servicing a wellbore, comprising establishing a pumping profile having a performance plan, operating a first pump according to a first pumping parameter value, and operating a second pump according to the second pumping parameter value, wherein the second pumping parameter value is selected relative to the first pumping parameter value to improve a conformance of a phase sensitive combined pump effect operational characteristic to the performance plan. A wellbore servicing system, comprising a pump group comprising a plurality of plungers wherein at least some of the plurality of plungers are substantially configured according to an equal phase angle distribution arrangement.

Abstract: A hydraulic power device for effecting operation of at least one load, the hydraulic power device including a motor having a predetermined motor speed rating and motor power rating, at least one pump operably coupled to the motor, the pump being configured to provide, to the at least one load, a predetermined hydraulic fluid flow at the predetermined motor speed rating, and a variable frequency drive connected to the motor, the variable frequency drive being configured to effect operation of the motor at a speed above the predetermined motor speed rating such that the at least one pump operates to provide an excess hydraulic fluid flow during operation of the motor substantially above the predetermined motor speed rating where the excess fluid flow is greater than the predetermined hydraulic fluid flow.

Abstract: A fluid ejection device includes: a pulse generation unit that changes the volume of a fluid chamber using a volume changing section to eject pulsating flow; a fluid supply unit including a pump chamber and a pump chamber volume changing section that changes the volume of the pump chamber to supply the fluid to the pulse generation unit; a drive control unit that inputs a pulsating flow drive signal for driving the pump chamber volume changing section and inputs a fluid supply drive signal for driving the fluid supply unit; and an operation command input unit that inputs an operation command to the drive control unit, wherein the fluid supply drive signal and the pulsating flow drive signal are input in conjunction with the input of the operation command.

Abstract: A machine having a pump overspeed protection system operating thereon includes an internal combustion engine, a plurality of ground engaging elements, and a drivetrain coupling the internal combustion engine and the ground engaging elements. The drivetrain includes a torque converter having a locked configuration and an unlocked configuration. The machine also includes a plurality of pumps driven by the internal combustion engine. An electronic control is in communication with the internal combustion engine, the torque converter, and the plurality of pumps.

Abstract: If a hydraulic system has several modes of operation, in particular a mode with a high pressure demand (II) and a mode with a high fluid flow demand (II), the hydraulic fluid pump has to be built with an accordingly high fluid flow output. Such a pump is expensive. Therefore it is suggested, to provide two pumps. I.e. a controllable main pump (2) is provided, which supplies the hydraulic consumer (6) during phases (I) of high pressure demand. During phases (II) of high fluid flow demand, normally, relatively low pressures are sufficient. Therefore, it is suggested to provide a parallel boost pump (9), which supplies the hydraulic consumer (6) in addition to the high pressure pump (2), if a high fluid flow is needed. Excess fluid flow output is avoided by controlling the fluid output flow of main pump 2.

Abstract: The present invention is a compressor compressing air, an electric motor driving the compressor, and an inverter variably controlling a rotating speed of the electric motor, the compressed air manufacturing facility is provided with a pressure sensor detecting a discharge pressure of the compressor at an upstream side position of a discharge air system connected to a discharge side of the compressor, and a control apparatus computing a pressure loss of the discharge air system in correspondence to a rotating speed of the electric motor, and changing a control range of the discharge pressure of the compressor at the upstream side position of the discharge air system on the basis of the computation in such a manner that a terminal pressure at a downstream side position of the discharge air system comes to a predetermined range.

Abstract: A driving device (10) for driving a unit (11) is specified, with a drive shaft (16) on which a plurality of rolling bearings (19 to 21) serving to drive respective functional elements of the unit (11) are arranged next to one another. The rolling bearings (19 to 21) are designed as unencapsulated needle bearings (22 to 24) and are arranged directly next to one another on the drive shaft (16) in such a manner that the inner ring (25, 26) of a needle bearing (22, 23) is in touching contact by means of its end surface (43, 44), which is located on an axial side, with the facing, axial end surface (46, 47) of the outer sleeve (32, 33) of the needle bearing (23, 24) following next axially.

Abstract: A system for changing a pump displacement configuration includes a blender that provides low-pressure fluid to a pump. The pump has a power end and fluid end, where the fluid end includes a number of plungers. The system includes an actuator that couples the power end with a selectable subset of the plungers. The system further includes a controller that selects a subset of the plungers according to a job pumping rate, a job pumping pressure, and/or a fluid end failure event indicator. The controller further commands the actuator to couple the selected subset of the plungers to the power end.

Abstract: A pump system includes pump having a control feature which, responsive to a supply of pressurized working fluid, reduces the pressure of the working fluid pressurized by the pump. The control feature is connected to the output of the pump by a regulating valve. The control feature receives pressurized working fluid to decrease the output of the pump in response to the pressure of the supplied working fluid. A regulating valve selectively connects the pressurized working fluid to the control feature. The regulating valve has a control port to receive pressurized working fluid from the pump to urge the valve to a closed position against a biasing force. A controllable valve is operable to interrupt the supply of pressurized working fluid to control port to alter the output pressure of the pump.

Abstract: A pump for one or more different process fluids is provided including a pumping chamber having a process fluid inlet and outlet coupled to a process fluid valve on each pumping chamber for selectively preventing and allowing flow of process fluid through the pumping chamber. An actuation mechanism for pumping actuating fluid to actuating fluid chambers is provided that is in communication with the actuating fluid chambers to permit flow into each actuating fluid chamber of incompressible actuating fluid. A diaphragm separates each pumping chamber from an associated actuating fluid chamber for separating process fluid from actuating fluid. The actuation mechanism is removable by a quick disconnect that provides for disconnection of the activation mechanism without affecting process fluid. Operation of the actuation mechanism to displace actuating fluid causes actuating fluid to flow only into each actuating fluid chamber having an opened process fluid valve, resulting in pumping.

Abstract: In a tandem piston pump (1) from which pump discharge pressure from four systems is extracted, a tilt axis direction of a front swash plate (14) and a tilt axis direction of a rear swash plate (54) are different to each other, respective discharge ports (23, 24) of a rear pump (50) are opened at a phase difference relative to respective discharge ports (21, 22) of a front pump (10), and respective pump ports (41, 42) of the front pump (10) and respective pump ports (43, 44) of the rear pump (50) are opened in different side faces (71, 72) of a port block (70).

Abstract: The invention concerns a method and device for controlling a number of infusion pumps 2-10, whereby each infusion pump (2-10) has an infusate assigned to it which is administered within a pre-determinable period of time assigned to it as an infusion at a pre-determinable infusion rate to a living being, whereby the infusion pumps (2-10) exchange control data for activating and deactivating the various infusions in a chronologically coordinated manner autonomously.

Abstract: A system and method of controlling torque of plural variable displacement hydraulic pumps in construction equipment are provided, which can control torque of the variable displacement hydraulic pumps so that the total amount of torque of the hydraulic pumps does not exceed the preset amount of torque by presetting the torque so that the engine does not stop even at maximum load of the hydraulic pumps or by presetting the speed of the engine or the used torque of the hydraulic pumps in consideration of the fuel economy or working speed.

Abstract: A controller for a system having at least one variable-capacity, pulse-width modulated compressor and at least one fixed-capacity compressor is provided. The controller may include processing circuitry that modulates the at least one variable-capacity, pulse-width modulated compressor to any capacity substantially between ten percent capacity and one hundred percent capacity. The processing circuitry may determine a desired capacity of the at least one variable capacity, pulse-width modulated compressor based on a load sensor signal and a current run percentage of the at least one variable capacity, pulse-width modulated compressor and may toggle the at least one fixed-capacity compressor between a run mode and a shutdown mode based on the desired capacity of the at least one variable-capacity, pulse-width modulated compressor.

Abstract: The invention relates to a wind turbine being provided with a fluid displacement means for ensuring a certain increased pumping capacity at a certain reduced rotational speed of the main shaft of the rotor and thus of a drive shaft from a gear box of the wind turbine. The invention also relates to a wind turbine being provided with fluid displacement means for ensuring a certain increased pumping capacity at a certain increased rotational speed of the main shaft of the rotor and thus of a drive shaft from a gear box of the wind turbine. The means may be mechanical, hydraulic, pneumatic or electrical. Additionally, the invention relates to a method for operating a wind turbine being provided with such fluid displacement means.

Abstract: A refrigeration cycle system is provided with a two-cylinder type rotary compressor having one compression mechanism which includes a switching mechanism for switching a back surface side of a blade between a low pressure mode and a high pressure mode and controlling the inner space of the cylinder chamber to the high pressure upon switching at the low pressure mode. In a high load state, a normal operation is performed by switching the pressure of the back surface side of the blade of the one compression mechanism at the high pressure mode. In a low load state, an uncompressed operation is performed by switching the pressure of the back surface side of the blade of the one compression mechanism at the low pressure mode and by controlling the inner space of the cylinder chamber to the high pressure to move the blade away from the roller.

Abstract: A pump system includes pump having a control feature which, responsive to a supply of pressurized working fluid, reduces the pressure of the working fluid pressurized by the pump. The control feature is connected to the output of the pump by a regulating valve. The control feature receives pressurized working fluid to decrease the output of the pump in response to the pressure of the supplied working fluid. A regulating valve selectively connects the pressurized working fluid to the control feature. The regulating valve has a control port to receive pressurized working fluid from the pump to urge the valve to a closed position against a biasing force. A controllable valve is operable to interrupt the supply of pressurized working fluid to control port to alter the output pressure of the pump.

Abstract: A pump for a combustion engine is disclosed. The pump may have at least one pumping member movable through a plurality of displacement strokes during a single engine cycle. The pump may also have a controller in communication with the pumping member. The controller may be configured to selectively reduce an amount of fluid displaced during at least one, but less than all of the plurality of displacement strokes. The reduction may be initiated in response to a demand for the displaced fluid.

Abstract: A split-pressure, dual-pump system for supplying hydraulic fluid to a multi-speed transmission is provided. The system includes a low-pressure work circuit operatively connected to a fixed displacement pump, and a high-pressure work circuit operatively connected to a variable displacement pump. The system also includes a regulator valve fluidly coupled to the variable displacement pump via a decrease circuit and an overage circuit for regulating the flow of fluid to the high-pressure work circuit. The invention consists of separating the high-pressure needs of the system into a separate work circuit from the low-pressure needs of the system, and optimizing pump design separately for each work circuit to maximize transmission efficiency and reduce parasitic losses. A method of supplying hydraulic fluid to a multi-speed transmission at variable flow and pressure is also provided.

Abstract: A pump system includes a fixed or variable capacity pump and a speed-related control mechanism to alter the capacity of a variable capacity pump or to alter the relief pressure of a fixed capacity pump in response to changes in the operating speed of the pump. A pressure generator comprising a volume of working fluid is rotated at a speed related to the operating speed of the pump and creates a forced vortex in the working fluid. The pressure induced in the working fluid of the forced vortex is used as a speed related control to alter the discharge pressure of the pump as desired.

Abstract: A system for changing a pump displacement configuration includes a blender that provides low-pressure fluid to a pump. The pump has a power end and fluid end, where the fluid end includes a number of plungers. The system includes an actuator that couples the power end with a selectable subset of the plungers. The system further includes a controller that selects a subset of the plungers according to a job pumping rate, a job pumping pressure, and/or a fluid end failure event indicator. The controller further commands the actuator to couple the selected subset of the plungers to the power end.

Abstract: A pump for a combustion engine is disclosed. The pump may have at least one pumping member movable through a plurality of displacement strokes during a single engine cycle. The pump may also have a controller in communication with the pumping member. The controller may be configured to selectively reduce an amount of fluid displaced during at least one, but less than all of the plurality of displacement strokes. The reduction may be initiated in response to a demand for the displaced fluid.

Abstract: A capacity variable type twin rotary compressor may include a casing, a motor, a first cylinder having a first compression space, a second cylinder fixed to one side of the first cylinder and having a second compression space, first and second intakes respectively formed in the first and second cylinders and each connected to a gas intake pipe, first and second vane slits respectively formed in the first and second intakes first and second rolling pistons eccentrically coupled to the motor and respectively housed in the first and second compression spaces, first and second vanes slidingly received in the first and second vane slits, respectively, an expansion groove formed at the second vane slit separate from the inner space of the casing, and refrigerant switching valves that allow refrigerant of intake and discharge pressures to be supplied into the second compression space and the expansion groove, such that the second vane contacts the second rolling piston to perform a power driving or separates therefr