Abstract: Driving arrangement (11) for a pump, compressor or similar, adapted to provide alternating pressure in at least two chambers (27a, 27b, 27?, 27?), such as chambers of a pump or compressor, as result of a reciprocating movement of a bar element (23). The bar element is connected to two movable pressure chamber faces being pistons (21a, 21 b) or plungers having fluid connection to said chambers, which bar element (23) is reciprocally supported in a housing (19). The driving arrangement further comprises an electric motor (31) which is adapted to provide the reciprocating movement of the bar element (23). The bar element extends through the rotor (31b) of the electric motor (31). The electric motor is an electric rotary motor. The invention also relates to a pump assembly with a plurality of such driving arrangements.

Abstract: A flow sensing dual pump switching system and method are provided that control the supply of fuel from a dual pump fuel system to a fuel metering unit. The system senses bypass pressure from the fuel metering unit to control the differential pressurization of the second pump. As the bypass is reduced, the pressure of the second pump is increased so that it may be added to that of the first pump to supply the increased fuel consumption needs of an engine. As the fuel consumption needs decrease, the flow from the second pump added to the first pump is reduced and the differential pressure of the second pump is similarly reduced. If the bypass pressure remains high, the switching system disconnects the output of the second pump from that of the first in favor of bypassing the flow to its input to reduce its differential pressure and conserve energy.

Abstract: A fan system includes a motor control module external to a motor housing of a fan assembly. The motor control module includes a speed control module. The fan assembly includes a fan and the motor housing. One or more first conductors are configured to connect the motor control module to a motor in the motor housing. One or more second conductors are configured to connect the motor control module to a host device control module. The host device control module is separate from the motor control module and is configured to generate a control signal. The speed control module is configured to control speed of the fan based on the control signal.

Abstract: A system includes a high pressure compressor having a gas input and a gas output. The gas input is coupleable to a gas field for receiving a gathered gas with a first gas pressure, and the gas output is coupleable to a gas export system for providing the gas with a second gas pressure, which is higher than the first gas pressure, to the gas export system. The system also includes a measuring unit coupled to the gas input. The measuring unit measures an input mass flow value indicative of an input mass flow at the gas input. The system also includes a mass flow control unit that is coupled to the measuring unit for receiving the measured input mass flow value and the gas input for controlling the input mass flow such that the measured input mass flow value corresponds to a set point input mass flow value.

Abstract: A method includes driving a fluid pumping unit having a plurality of pumping cylinders via a plurality of hydraulic cylinders respectively of a hydraulic power unit. The method further includes controlling activation of the hydraulic power unit such that each stroke of the corresponding piston assembly between the top dead center and the bottom dead center follows a corresponding trapezoidal velocity profile with respect to a time duration. Controlling activation includes controlling flow of a hydraulic fluid in the hydraulic power unit so as to control the corresponding trapezoidal velocity profile with respect to the time duration of the corresponding piston assembly to obtain a predefined flow rate of the fluid medium from the pumping unit.

Abstract: A fan system includes a pulse signal generation portion and a plurality of fans. Each of the plurality of fans preferably includes a motor portion; an impeller arranged to be rotated by the motor portion; a drive circuit arranged to drive the motor portion; a rotation detection portion arranged to detect rotation of the motor portion; and a rotation rate control circuit arranged to, based on a reference pulse signal supplied from the pulse signal generation portion and an actual rotation pulse signal supplied from the rotation detection portion, exercise feedback control on a rotation rate of the motor portion in accordance with a period of the reference pulse signal.

Abstract: A water supply apparatus is capable of performing a backup operation, without lowering water supply capability, when a failure has occurred in one control substrate due to surge or noise caused by lightning or sensor wear, by switching to the other control substrate, and capable of reliably performing the backup operation. The water supply apparatus includes: a plurality of pumps; a plurality of inverters each configured to change and control a rotational frequency of a corresponding one of the plurality of pumps; and a plurality of control substrates configured to control the plurality of inverters. When an abnormality occurs in one control substrate, other control substrate backs up the one control substrate to thereby allow the water supply apparatus to continue its operations. The one control substrate, the plurality of inverters, and the other control substrate are connected in series by communication lines.

Abstract: Embodiments of the invention provide battery backup sump pump (BBU) systems and methods. The BBU systems and methods can be used with a battery and an alternating current power source to charge the battery. The BBU systems and methods can be adapted to be a portable power source for AC and DC external devices.

Abstract: A method of controlling fluid flow in a fluid network system by means of a plurality of fluid machines. The disclosure provides a simple empirical method of identifying network characteristics of the fluid network system used for providing the required fluid flow rate in the fluid network system utilizing minimal fluid machine power. The method includes the steps of determining a relation between a change in fluid machine speed and a corresponding change in fluid flow rate for each of the plurality of fluid machines empirically; determining a minimum total fluid machine power which provides a minimum required flow rate in the fluid network system based on a constraint involving the relation between the fluid flow rate and the corresponding fluid machine speed, and controlling a speed of the plurality of fluid machines such that the minimum total fluid machine power in the fluid network system is attained.

Abstract: Systems and methods for monitoring operation of a pump, including verifying operation or actions of a pump, are disclosed. A baseline profile for one or more parameters of a pump may be established. An operating profile may then be created by recording one or more values for the same set of parameters during subsequent operation of the pump. The values of the baseline profile and the operating profile may then be compared at one or more points or sets of points. If the operating profile differs from the baseline profile by more than a certain tolerance an alarm may be sent or another action taken, for example the pumping system may shut down, etc.

Abstract: An approach is provided in which a cooling manager detects a failed fan included in an electronic enclosure. The electronic enclosure includes multiple fans that each cool different component areas in the electronic enclosure. The cooling manager selects an airflow compensator that corresponds to a functioning fan included in the electronic enclosure, which includes a fixed perforated member and a movable perforated member. In turn, the cooling manager adjusts the selected airflow compensator to redirect a portion of airflow generated by the functioning fan to the component area corresponding to the failed fan.

Abstract: Example fluid circuits (e.g., within aircrafts) include first and second pump assemblies. The first pump assembly has an electric motor and a first fluid pump. The first fluid pump is coupled to the electric motor and has a case drain port that is in fluid communication with a case drain region of the first fluid pump. The second pump assembly is powered by hydraulic pressure from the first fluid outlet of the first fluid pump and functions to augment flow through the case drain region of the first fluid pump.

Abstract: A compressed gas supply unit has scroll compressors. Gas discharged from the scroll compressors travels through a main supply passage and is reserved in a reservoir tank, after which the gas is supplied to a gas recipient from a supply passage. The scroll compressors include inverter devices that allow for independent modulation of the speeds of respective drive motors. The controller includes a speed range setting unit that sets an upper speed limit and a lower speed limit of the scroll compressors, a speed sum calculating unit that calculates a sum of speeds of the scroll compressors based on a load of the compressed gas supply unit, and a speed setting unit that allocates the calculated sum of speeds among the scroll compressors to set speeds for scroll compressors respectively.

Abstract: A machine for replacing used transmission fluid in a vehicle with new transmission fluid includes a frame having a housing. The machine includes a pair of service hoses that extend from the machine and connect to the vehicle's transmission fluid system for placing the machine in the fluid flow. A new fluid tank and a used fluid tank are provided. A pump and a manifold are associated with each of the tanks. The pumps provide for the selective withdraw or insertion of fluid into or out of the tanks. A display on the housing presents an operator of the machine with various tasks or options the machine can perform. A processor controls activation of the pumps and other electrical components based on inputs received by the display. Scales are provided under each tank for determining the amount of fluid going into and out of the tanks during the exchange process.

Abstract: A fuel supply device according to the present invention comprises a first fuel pump for forcing fuel from a fuel tank to a fuel passage, a first electric motor for driving the first fuel pump, a second fuel pump for forcing fuel from the fuel tank to the fuel passage, a second electric motor for driving the second fuel pump, a supply flow rate sensor for detecting flow rate in the supply passage, and a control device for controlling the flow rate in the supply passage to follow a desired value thereof, by regulating rotational speeds of the first and second electric motors depending on a difference between the desired value and a detected value of flow rate in the supply passage.

Abstract: A counter-rotating axial-flow fan may be controlled to improve both cooling efficiency and operating efficiency. A first motor and a second motor are started in a given starting mode. Then, if the temperature of an object to be cooled is higher than a given reference temperature, the rotational speed of the first motor and the rotational speed of the second motor are controlled in a predetermined cooling efficiency mode that gives priority to cooling the object to be cooled over the operating efficiency of the counter-rotating axial-flow fan. If the temperature of the object to be cooled is equal to or lower than the given reference temperature, the rotational speeds of the first and second motors are controlled in a predetermined operating efficiency mode that maintains the object to be cooled at a temperature equal to or lower than the given reference temperature and reduces the power consumption of the counter-rotating axial-flow fan.

Abstract: An environmental control system having parallel compressors includes a first compressor driven by a first motor, the first compressor being operable for fluidly directing a first flow at a first flow rate through the first compressor. Also included is a second compressor driven by a second motor, the second compressor being operable for fluidly directing a second flow at a second flow rate through the second compressor. Further included is a monitoring component configured to compare the first flow rate to the second flow rate.

Abstract: A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

Abstract: A compressor control apparatus and method, and a refrigerator including the same, are provided. In a refrigerator having two compressors, starting of two compressors may be staggered to reduce an effect of the suction pressure and discharge pressure between the two compressors, to provide for stable operation of the compressors, and improve reliability and power consumption.

Abstract: Disclosed is a system for allocating torque, supplied in one embodiment by an engine, to multiple variable and fixed displacement pumps coupled together in a series by coupling elements interspersed between the pumps. A controller is included which monitors the torque applied to each coupling element. The controller automatically varies displacement in one or more of the variable displacement pumps to prioritize and allocate torque to optimize available torque while keeping the torque applied to each coupling element within the torque limit for that particular coupling element.

Abstract: A hydraulic pressure producing system for an automatic transmission, and a control method thereof may include a first hydraulic pump adapted to generate hydraulic pressure for shifting, a second hydraulic pump adapted to additionally generate hydraulic pressure when hydraulic pressure supplied from the first hydraulic pump is insufficient, an accumulator adapted to store hydraulic pressure excessively generated from the first hydraulic pump, and a control unit controlling the second hydraulic pump. The method may include operating the first hydraulic pump in a state of idle stop, predicting a finish point of the idle stop state, starting operation of the second hydraulic pump prior to a predetermined time from the predicted finish point, operating the second hydraulic pump with a predetermined maximum rotation speed, and operating the second hydraulic pump with a target rotation speed.

Abstract: A float switch to control at least two pumps has a guide with two normally-closed micro-switches and a float rod slidably mounted thereto allowing reciprocating vertical movement. The float rod has one or more lower cam surfaces cooperating with the micro-switches to sequentially release them from their engaged positions to their normal positions during upward movement of the float rod. A float is slidably mounted to the float rod between upper and lower float stops. The shape of the lower cam surfaces is such that the weight of the float rod is insufficient to allow the float rod to move downwardly against resistance provided either by the first micro-switch or separately by the second micro-switch and the weight of the float rod combined with at least a portion of the weight of the float is sufficient to overcome either such resistance and to move the float rod downwardly.

Abstract: An oil pump system for a vehicle includes: a vane pump having a plurality of vanes which respectively project retractably from a plurality of vane accommodating grooves provided in a rotor so as to be brought into sliding contact with a cam surface, the vane pump being adapted to supply a hydraulic fluid to an automatic transmission; an electric power-driven oil pump for assisting the hydraulic pressure of the hydraulic fluid during an idling stop of the automobile; and an ECU for controlling its operation. During an idling stop, the hydraulic fluid is fed to the automatic transmission by the operation of the electric power-driven oil pump to assist the hydraulic pressure, while the hydraulic fluid is fed with pressure also to the vane accommodating grooves to press the vanes against the cam surface.

Abstract: A compressor system is disclosed, comprising a first pump driven by a D/C motor, a second pump driven by an A/C motor, and a switch which allows a user to manually selectively engage of one of the D/C motor or A/C motor, including a gauge having a user settable shut-off mechanism which interrupts power to at least one of D/C or A/C motors. Also disclosed is a gauge configured to display system pressure independent of the user settable shut-off mechanism. A gauge having a rotatable bezel with a needle stop comprising a first needle rotatably coupled to a gauge shaft, and a second needle fixable coupled to the gauge shaft, and a spring disposed between the first and second needles, the spring configured to bias the first needle into the second needle so changes in pressure causes rotation of both is also disclosed.

Abstract: Systems and methods for monitoring operation of a pump, including verifying operation or actions of a pump, are disclosed. A baseline profile for one or more parameters of a pump may be established. An operating profile may then be created by recording one or more values for the same set of parameters during subsequent operation of the pump. The values of the baseline profile and the operating profile may then be compared at one or more points or sets of points. If the operating profile differs from the baseline profile by more than a certain tolerance an alarm may be sent or another action taken, for example the pumping system may shut down, etc.

Abstract: A multiphase alternating current permanent magnet synchronous electric motor is coupled to an actuator. A sensorless electric motor drive control system controls operation of the electric motor. An initial phase angle and a rotational speed of a rotor of the electric motor are estimated. Operation of the sensorless electric motor drive control system and the electric motor are monitored using the estimated initial phase angle and the estimated rotational speed of the rotor of the electric motor. A fault in one of the sensorless electric motor drive control system and the electric motor is detected based upon the monitored operation.

Abstract: The invention relates to a method of realizing a vacuum in a vacuum chamber. The vacuum chamber is connected to a pumping system shared by a plurality of vacuum chambers. The method includes separately pumping down each vacuum chamber. The invention further relates to n arrangement of a plurality of vacuum chambers connected to a pumping system. In this arrangement, the pumping system is arranged for pumping down each vacuum chamber separately.

Abstract: A serial axial fan preferably includes a first impeller and a second impeller each having a plurality of blades radially extending with a predetermined rotation axis as the center, a first motor portion, a second motor portion, a first housing, and a second housing. The first motor portion has a first circuit board on which at least one electronic component arranged to control the driving of the first impeller is mounted. The second motor portion has a second circuit board on which at least one electronic component arranged to control the driving of the second impeller is mounted. The first and second circuit boards are electrically connected. The driving of the first impeller and the driving of the second impeller are controlled by the electronic component disposed on at least one of the first and second circuit boards.

Abstract: A fan control system includes first and second fan control units. Each fan control unit includes a connector, a delay circuit, a switch unit, and a control circuit. Each connector is connected to a corresponding fan interface to receive a voltage signal. The delay circuit of the first fan control unit delays the voltage signal for a first period of time, and turns on the corresponding switch unit after the first period of time. The delay circuit of the second fan control unit delays the voltage signal for a second period of time, and turns on the corresponding switch unit after the second period of time. Each control circuit receives the corresponding delayed voltage signal, to start the corresponding fan. The first period of time is unequal to the second period of time.

Abstract: A system and method of spread-spectrum fan control for an air-cooled system is provided for reducing the vibrational and acoustical noise associated with the air-cooled system. The method includes generating a first control signal that controls a blade-passing frequency of a first cooling fan and a second control signal that controls a blade-passing frequency of a second cooling fan, wherein the first and second control signals may be pulse width modulated (“PWM”) signals. One or more noise generators independently vary duty cycles for the first and second PWM signals within a range around respective first and second blade-passing frequency set points. As a result, the blade-passing frequencies for the first and second cooling fans are independently and randomly modulated within a range around the respective first and second blade-passing frequency set points.

Abstract: A compression method, a multistage compression system and an air separation method and plant in which a gas is compressed in a series of compression stages to produce a compressed gas and each of the compression stages incorporate a variable speed compressor. In such compression method and system, the compressed air is produced at a pressure that remains stable during both normal operational conditions and during turn down conditions during which the flow rate of the gas is reduced. This reduction is accomplished by reducing the speed of the compressor in an initial compression stage such that the compressor operates at a point along its peak efficiency operating line at which the pressure ratio is directly proportional to the flow rate and such that the lower turn down flow rate is obtained at a reduced pressure which is made up in successive compression stages.

Abstract: A multi-stage compression installation is formed of a main pipe (2) emerging in a baffle plate (3), where at least two compressors (4, 5) are mounted in series each having its own drive member (9, 10). The installation is equipped with a system for determining the pressure at the output of the main pipe (2), the installation being connected to a control box (8). Typically, the control box (8) is connected to at least two of the drive members (9, 10) of the compressors (4, 5) and ensures monitoring of the compressors such that the latter rotate jointly whether charged or uncharged. Thus, the compressors (4, 5) are jointly charged based on the pressure prevailing in the baffle plate (3), such that the charging of the compressor representing the overpressure stage, the compressor(s) of the lower compression stages are automatically and jointly charged.

Abstract: A compressor system includes a lead compressor operable to produce a flow of compressed fluid at a first output and a lag compressor operable to produce a flow of compressed fluid at a second output. The sum of the first output and the second output defines a system output. A lead variable speed motor is operable to drive the lead compressor at a first compressor speed to vary the first output and a lag variable speed motor is operable to drive the lag compressor at a second compressor speed to vary the second output. A sensor is operable to measure a system load, and a lead motor drive is operable to control the speed of the lead variable speed motor and to set a desired operating state of the lag variable speed motor in response to a comparison of the system load and the system output.

Abstract: The mechanism subject of the invention is basically a modification of the “Multichamber and motor pumps for generating ultra high pressure” where more efficiency is acquired in the space and in its operation upon having several chambers for each motor pump which is installed, mainly the ones located towards the exterior. Or each chamber permits in the inside of its walls the injection of liquid at intermediate pressures between the pressure the chamber has in its interior and its exterior.

Abstract: A method for controlling operation of a pump unit, where the pump unit includes a primary piston pump having a primary piston and a secondary piston pump having a secondary piston. The primary piston pump is fluidically connected with the secondary piston pump. The primary piston pump includes an inlet valve and an outlet valve, and the pump unit operates periodically according to a pump cycle. The method includes determining a fluid pressure of fluid dispensed by the pump unit, and performing a closed loop control of a position of the primary piston in dependence on the fluid pressure of the fluid dispensed by the pump unit during a first time interval of the pump cycle.

Abstract: A pump control system includes a plurality of different variable speed pumps. Each of the pumps can be operated at a different speed to equalize pump loads. A system wide proportional integral differential control loop increases and decreases the speed of all pump motors to maintain a desired system output pressure. A second proportional integral differential control loop associated with each pump adjusts pump speed to equalize a load profile for each respective pump.

Abstract: A pump arrangement and method of regulating pressure of a pump arrangement are provided. The pump arrangement includes an actuation pump, a pressure regulating valve, and a control valve. The actuation pump has an actuation pump outlet providing an actuation pump discharge flow. The actuation pump discharge flow is piped to opposite sides of a regulator valve member that selectively adjusts an amount of fluid that is bled from the actuation pump outlet such that the actuation pump outlet pressure is used to regulate the actuation pump discharge pressure. The actuation pump discharge flow is separated into first and second portions to provide opposing forces on the regulator valve member. The control valve is operably interposed between the actuation pump outlet and the valve member to selectively adjusts the amount of biasing applied by the second portion of the actuation pump discharge flow on the regulator valve member.

Abstract: A fan control system includes a first fan, a second fan adjacent to the first fan, a first motor that rotates the first fan, a second motor that rotates the second fan, and a control unit. The control unit controls the rotational speeds of the first motor and the second motor. The control unit decreases the rotational speed of the first motor and increases/decreases the rotational speed of the second motor when the rotational speed of the first motor must be decreased, The control unit can decrease the rotational speed of the second motor when the rotational speed of the first motor whose rotational speed has been decreased is lower than a prescribed rotational speed, and increase the rotational speed of the second motor when the rotational speed of the first motor whose rotational speed has been decreased is higher than the prescribed rotational speed.

Abstract: A method for controlling a hydraulic flow within a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an engine adapted to selectively transmit power to an output, wherein the transmission utilizes a hydraulic control system serving a number of hydraulic oil consuming functions includes monitoring minimum hydraulic pressure requirements for each of the functions, determining a requested hydraulic pressure based upon the monitoring minimum hydraulic pressure requirements and physical limits of the hydraulic control system including a maximum pressure, determining a desired flow utilizing a hydraulic control system flow model based upon the requested hydraulic pressure, and utilizing the desired flow to control an auxiliary hydraulic pump.

Abstract: The present invention refers to a control equipment for a pressure set, said pressure set being made up of a main pump and at least one auxiliary pump, characterized in that it comprises a housing fitted to the exit of the main pump, therewithin it is provided with: a pressure transducer; a minimum flow detector associated to the circulation pipe that is related to the main pump; a frequency changer to regulate the flow speed that is flowing through the hydraulic pipe that is connected to the main pump; and an electronic control circuit electrically connected to the pressure transducer, the flow detector, so that based on the signals received from them it sends a signal to the frequency changer so as to regulate the working parameters of the main pump and at least one auxiliary pump, keeping the pressure value unchanged throughout the workings of the pressure set.

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: For water-jet surgery pump devices are known by means of which a sterile fluid is transported through a reservoir to the surgical instrument by means of piston pumps or similar volumetrically transporting pumps. In accordance with the present invention it is proposed either to construct drive means for the pumps in such a way that their suction cycle is shorter than the output cycle, or to provide a pump with at least three pump chambers and to construct the drive means in such a way that the suction and output cycles of the pump chambers overlap one another.

Abstract: An information processing apparatus sets a driving keeping voltage for keeping driving of a fan to a voltage that is higher than a voltage that is applied to the fan when the fan is determined not to be rotating after decreasing the voltage that is applied to the fan in a state where the fan is rotating.

Abstract: There is proposed a lubricant system having a plurality of motor-driven pumps operating in parallel as main oil pumps, wherein even if at least one of the main oil pumps stops, the other normally operating main oil pumps do not stop due to overload of a motor. A lubricant system 7 comprises a hydraulic pressure piping 9, a plurality of lubricant pumps 10 arranged in parallel, a plurality of AC motors 11 driving each of the lubricant pumps 10, an error detector 24 detecting a presence or absence of an error in an operating state of each of the AC motors 11, a pressure loss addition unit 25 configured to increase pressure loss in the hydraulic pressure piping 9, and a controller 26 causing the pressure loss addition unit 25 to increase pressure loss when the error detector 24 detects an error in at least one of the AC motors 11.

Abstract: A method of pressure control for transmissions having a hydraulic circuit selectively communicating with first and second pumps via first and second regulators includes commanding communication to the hydraulic circuit to transition from the first to the second pump and the PCS to set the regulators to a high pressure-regulation level. The hydraulic circuit line pressure is raised to an elevated value exceeding a target value. The line pressure is lowered from the elevated to the target value at or after completing the transition to the second pump. The method may include transitioning communication with the hydraulic circuit from the second to the first pump. The PCS maintains the regulators at the high level and line pressure is raised to the elevated value. PCS sets the regulators to a low level, and line pressure returns to the target only at or after completing the transition to the first pump.

Abstract: If it is determined that a malfunction has occurred in an electrical hydraulic pump and the hydraulic fluid is not supplied to a high hydraulic pressure supplied portion from the electrical hydraulic pump, the hydraulic fluid is supplied to the high hydraulic pressure supplied portion from a mechanical hydraulic pump that usually supplies the hydraulic fluid to a low hydraulic pressure supplied portion. In this case, the hydraulic pressure that is generated by the mechanical hydraulic pump is increased by increasing the output from the engine that drives the mechanical hydraulic pump.

Abstract: Apparatus for maintaining differential internal fluid pressure in a dual fluid chamber object where it is desired for one chamber to have greater internal pressure than the other includes a sensor for generating a differential signal indicating the difference in pressure between the chambers, a pressure sensor for generating a pressure signal indicating the pressure inside the chamber desired to have less pressure, a comparator for generating a first output when the differential signal is less than a predetermined minimum differential value, a second comparator for generating a second output when the pressure signal is less than a predetermined minimum pressure value, where the predetermined minimum pressure value biased by the first output, and blowers coupled to the respective chambers and responsive to said first and second outputs respectively.

Abstract: Method for adjusting a compressed air installation using several electrically driven compressors of what is called the “loaded/unloaded” type and/or the turbo compressor type and/or the compressor type with variable rotational speed, wherein these compressors are each connected to a single compressed air network with their outlets, and wherein use is made of a control box which makes it possible to adjust the pressure in the compressed air network around a target pressure to be set. The adjustment takes place by controlling the flow of one or several of the compressors, in particular in order to increase the overall flow supplied by the compressors when the pressure drops too much, and in order to lower the overall supplied flow when the pressure becomes too high.

Abstract: A control apparatus for controlling two oil pumps which are provided on a vehicle wherein the two oil pumps are selectively driven by respective different drive power sources such that one of the two oil pumps is operated while the other oil pump is held at rest, the control apparatus including an air removal control portion configured to temporarily operate the above-indicated other oil pump during an operation of the above-indicated one oil pump, to remove air staying at and around an oil inlet of the above-indicated other oil pump.