Abstract: An ultra high pressure pump comprising a servo motor coupled to a piston having a head arranged within a cylinder to define a pumping chamber, whereby the servo motor rotation causes reciprocal displacement of the piston to pressurise fluid in the pumping chamber to pressures greater than 50,000 psi, the servo motor having a feedback loop coupled to a computer, the feedback loop including a pressure feedback signal to control the pump pressure in real time.

Abstract: A self-adjusting fluid pump that includes a piston pump containing at least one piston with a pressure sensor. The fluid pump including at least one fluid-containing pump chamber within the piston pump, adjacent to said piston, wherein advancing the piston causes fluid flow from the pump chamber to a biological destination, and retracting the piston causes fluid to passively till the pump chamber. A microprocessor, senses piston pressure to calculate the rate of fluid input flow into the pump chamber for each pump cycle. If the output flow rate deviates from the input flow rate by a pre-specified value range, the microprocessor adjusts the piston pump to match the output flow rate with the input flow rate by increasing or decreasing stroke rate (piston velocity), stroke volume, or a combination of both.

Abstract: Disclosed are an operation control device of a compressor, which can reduce motor loss by applying an AC power to a motor of the compressor without a switching operation of a control unit, and a method thereof. The operation control device of the compressor comprises: a capacitor electrically connected to a motor of the compressor and having a predetermined capacitance; a control unit connected in series to the motor of the compressor and applying an AC power to the motor of the compressor according to a control signal; and a controller detecting a load variation amount on the basis of a current and voltage applied to the motor of the compressor and controlling on/off of the control unit according to the detected load variation amount.

Abstract: A fluid compressor for compressing fluids and a method for operating the same are provided. The fluid compressor includes a compression chamber with an inlet for the fluid and an outlet for compressed fluid. The fluid compressor further includes a piston disposed within the compression chamber. The fluid compressor includes a driving system that includes piezoelectric actuator configured to cause displacement of the piston in the compression chamber. The driving system further includes an amplifying element that is coupled to the piezoelectric actuator in the direction of the movement of the piston to enhance the displacement of the piston caused by the piezoelectric actuator. One end of the amplifying element is fixed to a base of the fluid compressor and the piezoelectric actuator is disposed between the amplifying element and the piston.

Abstract: A method and apparatus is disclosed for determining pressure provided by a pump of a topical negative pressure (TNP) system. The method includes the steps of determining a value associated with a measured pressure, determining a difference between the measured pressure value and a predetermined desired value and increasing or decreasing a speed of pumping of the pump responsive the to difference.

Abstract: A system for powering a compressor. The system may include a power generation unit adapted to generate AC power. An electric motor may be coupled to the power generation unit and adapted to turn at a rate proportionate to a frequency of the AC power. A compressor may be coupled to the electric motor, and an output pressure of the compressor may be directly dependent on the rate that the electric motor turns. A control system may be coupled to the power generation unit and to the compressor, and the control system may be adapted to vary the frequency of the AC power generated by the power generation unit, thereby varying the output pressure of the compressor.

Abstract: A liquid degassing apparatus is arranged to limit pervaporation through a membrane by attenuating pressure oscillations developed by a vacuum pump. The attenuation is obtained through a combination of one or more flow restrictors and added volume chambers fluidly interposed between the degassing chamber and the vacuum pump. The pressure oscillation attenuation may further inhibit cross-contamination of pervaporated solvents among a plurality of distinct degassing chambers.

Abstract: Embodiments disclosed provide a customizable dispense system implementing modular architecture, the customizable dispense system comprising a smart controller configured to operate various pneumatic pumps and motor pumps in various semiconductor manufacturing processes that are sensitive to defects in printed patterns. The smart controller is configured to, upon switching from communicating with a first pump to a second pump, automatically recognize the second pump and apply a control scheme to control the second pump, which may be a motor pump or a pneumatic pump. The switching may be due to physical disconnection of the first pump and physical connection of the second pump or it can be entirely done via software. The smart controller may be connected to track and a variety of devices, including smart filters.

Abstract: A universal controller (16) for an electric motorized pump (18) having a mechanical switch (19) for turning on and off electrical power to the pump, and method of operation of same. The controller controls output pressure of the pump based on controlling the speed of the pump (for example by applying voltage over a greater portion of a duty cycle), so as to provide an optimal operating pressure derived from an automatically determined value for the pressure at which the mechanical switch opens and disrupts electrical power to the pump. It is manufactured as a standalone assembly, not attached to a pump. It can be operated so as to automatically seek and determine a switch-opening pressure for the switch (19), at which the pump pressure switch opens and so interrupts electrical power to the motor, and to then choose an operating pressure below the switch-opening pressure.

Abstract: A pressure-controlled liquid supply system uses a pump control device to switch a pump on and off in response to a pressure level in the pumped liquid. The pump control device minimizes short cycling of the pump by preventing shut off of the pump while a flow is present through the pump control device and by delaying the shut off of the pump. The pump control device also avoids a significant drop in the output pressure by creating a reduced pressure zone, which provides the switch pressure used to switch the pump off.

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 compressor control method includes providing variable aerodynamic sizing of fluid flow through a compressor at multiple operating points of the compressor. A head is determined for an operating point, based on a process input at that operating point. Further, for that operating point, a control pressure number is determined as a function aerodynamic flow sizing at that operating point. The control pressure number is determined a function of the head divided by the square of a tip speed of the impeller of the compressor. An operating speed setpoint is determined based on the determined head and control pressure number.

Abstract: An airflow volume sensing system for determining the flow rate through a fan includes a curved inlet cone with a pressure sensor at the minimum diameter of the cone, wherein the flow volume sensing system is particularly suited for FC centrifugal fans (centrifugal fans with forward curved fan blades). With an FC fan, the minimum diameter of the inlet cones interior surface is adjacent the fan wheel, and the static pressure there is at a minimum value. A predetermined relationship between the static gage pressure at that point and the volume flow rate through the fan is applied regardless of variables such as fan speed, fan housing geometry, supply air duct configurations, return air duct configurations, location of various heat exchangers or filters, etc. In some examples, a single pressure sensor senses an average of a plurality of pressure taps wherein each tap is at approximately the same minimum pressure.

Abstract: Device for adjusting the operating pressure of an oil-injected compressor installation with a compressor element (2) driven by a motor (4) with an adjustable rotational speed and a control module (13), where the device (15) is provided with a controlled inlet valve (16) which is connected to the air inlet (5) and a blow-off mechanism (17) which can be closed by means of a blow-off valve (19), where the inlet valve (16), the blow-off valve (19) and the control module (13) are electrically controllable components which are connected to an electronic control unit (22) for adjusting the operating pressure (Pw), which is measured by an operating pressure sensor (23).

Abstract: A method for controlling the motor of an air handling system to provide a desired output of flowing air therefrom while minimizing the power used by the motor, including operationally connecting a switched reluctance electric motor to a blower, operationally connecting an electronic controller to the switched reluctance electric motor, operationally connecting at least one sensor to the electronic controller, measuring at least one environmental parameter with the at least one sensor, inputting the desired air flow into the electronic controller, calculating the minimum motor speed necessary to provide the desired air flow, and sending a control signal from the electronic controller to the motor to control the motor to the minimum motor speed necessary to provide the desired air flow.

Abstract: A device executing a start-up control method for an electric scroll compressor has a thermistor (18) and a pressure sensor (20) which, prior to the start-up of the scroll compression unit, detect temperature and pressure of a suction refrigerant introduced into the compression unit (2), and a controller (10) for controlling driving of a motor (4) of the compression unit (2) at the start-up of the compressor. The controller (10) determines at the start-up of the compressor whether or not a liquid refrigerant exists in the compression unit (2) on the basis of the detected temperature and pressure; selects either a normal start-up mode or a liquid-discharge mode in which the rotational speed of the motor (4) is regulated to be lower than in the normal start-up mode, according to the determination result; and controls the start-up of the compression unit (2) through the motor (4) according to the selected mode.

Abstract: A method for regulating a motor-driven pump of an SCR system, the pump delivering a pressure, being subjected to a hydraulic torque in relation to this pressure and also to a resistive torque and being driven by an electric motor including coils supplied with a current and developing a torque in relation to this current, according to which to regulate the pump, use is made of a mechanism to measure the current in the coils of the motor, of a regulator of overall current consumed by the motor, and of a model of the relation between the current and the pressure using an estimate of part of the resistive torque, namely the dry frictions, obtained by rotating the pump under no-load conditions at different speeds and by measuring the associated current.

Abstract: A method and apparatus for a pump and a pump control system. The apparatus includes a pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump.

Abstract: Embodiments of the invention provide a pump control circuit for use with a pump. The circuit includes a pressure sensor capable of sensing a pressure in the pump and a microcontroller coupled to the pressure sensor and to the pump. The microcontroller switches operation of the pump between a high-flow mode and a low-flow mode. When in the high flow mode, the microcontroller limits a current provided to the pump to a high-flow current limit value that is not dependent on the sensed pressure. When in the low flow mode, the microcontroller limits the current provided to the pump to a low-flow current limit value that is less than the high-flow current limit value and that changes depending on the sensed pressure.

Abstract: A medical pump with a closed loop stroke feedback system and method, for use with a pumping chamber, for example in a cassette, is disclosed. The pump includes a pumping element that intermittently pressurizes a pumping chamber during a pumping cycle. A pressure sensor detects the pressure exerted by the pumping element on the pumping chamber. A position sensor detects the position of the pumping element. A processing unit processes pressure data from the pressure sensor and position data from the position sensor to determine a calculated stroke volume of the pump for a pump cycle, and to adjust a stroke frequency of the pump to compensate for variation in the stroke volume.

Abstract: An HV-ECU performs a step of detecting an atmospheric pressure, a step of calculating a maximum value of a boost voltage corresponding to the atmospheric pressure by using a map, and a step of setting the maximum value as a system voltage value and controlling a DC/DC converter. Moreover, the HV-ECU may calculate a resistance value of a gate resistance of a switching element corresponding to the atmospheric pressure by using the map and control the gate resistance to achieve the set resistance value.

Abstract: A compression method, a multistage compression system incorporating such method and an air separation method and plant utilizing such compression method and system 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 along a 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: Provided is a portable vacuum generator that can effectively save battery power of a vacuum pump for absorbing exudates from a suction head that is connected to a tube, and a medical suction device using the same.

Abstract: A motor with associated load sensor is connected to a circulation pump of a swimming pool circulation system. The load sensor performs the function of a safety vacuum release system by detecting underload of the motor. Underload is now discovered to be reliably indicative of blockage on the intake side of a circulation pump. A switch controlled by the load sensor shuts off the motor in response to a suitable underload. Vacuum on the intake side of the circulation pump neutralizes, thereby freeing a person or object blocking the suction line.

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 system includes a housing; a first fan having a first inlet and a second fan having a second inlet, the first fan and the second fan mounted in a wall of the housing, the first fan and the second fan oriented to draw air into the housing; a device in the housing, the device positioned to receive airflow from the first fan and the second fan; and a controller for controlling the first fan and the second fan, wherein the controller is configured to initiate a cleaning cycle during which the first fan is on and the second fan is off to cause backpressure airflow to flow through the second inlet in a reverse direction for a first time period and the first fan is off and the second fan is on to cause backpressure airflow to flow through the first inlet in a reverse direction for a second time period.

Abstract: An apparatus includes a valve housing having an inlet port, a first chamber with a first outlet port, and a second chamber with a second outlet port. A first valve opens between the inlet port and the first chamber under a first level of pneumatic pressure at the inlet port. A second valve opens between the first chamber and the second chamber under a second, greater level of pneumatic pressure in the first chamber. A third valve opens between the second chamber and the first chamber under a third level of pneumatic pressure in the second chamber, with the third level being less than the first level.

Abstract: In order to provide a compressed air manufacturing facility which can increase a stability of a supply pressure while obtaining an energy saving effect, in a compressed air manufacturing facility provided with a compressor compressing an 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 method and apparatus for determining a fluid level and/or output flow during operation of a centrifugal pump, are provided, which may be used for production of gas and/or oil from a well, and include a vector feedback model to derive values of torque and speed from signals indicative of instantaneous current and voltage drawn by the pump motor, a pump model which derives values of the fluid flow rate and the head pressure for the pump from torque and speed inputs, a pumping system model that derives, from the estimated values of the pump operating parameters, an estimated value of fluid level and other pumping system parameters. Controllers responsive to the estimated values of the pumping system parameters control the pump to maintain fluid level at the pump input, near an optimum level, or within a safe operating range and/or output flow from the pump.

Abstract: A liquid injection and ratio control system is provided for blending an additive into a main flow line at a controlled ratio. The system automatically detects variances in temperature, pressure, and additive concentration and provides compensation thereto. The system also provides for automatic flow detection, calibration responsive to a level gauge, automated data collection, and wireless bi-directional communication.

Abstract: A fuel supply apparatus includes a fuel pump having an electrically driven motor. A controller is connected to the motor of the first fuel pump and is capable of determining an estimated pressure based on a value of current supplied to the motor and a rotational speed of the motor. The controller controls the motor so that the estimated pressure becomes relatively equal to a target pressure.

Abstract: An arrangement having a piston configured to move along an axial pathway a rotating seal configured to seal an inside environment from an outside environment, the rotating seal configured to be acted upon by a pressure exerted from the piston, a differential pressure sensor measuring a pressure difference between a first fluid from the outside environment and a second fluid on the inside environment, a motor connected to the piston, the motor configured to actuate the piston to a position along an axial pathway and an electronic feedback control system connected to the motor, the electronic feedback system configured to interface with the differential pressure sensor and maintain a pressure generated by the piston onto the rotating seal to a desired pressure.

Abstract: The Water Distribution System is specifically applicable in cold climates in which water distribution systems may be subjected to freezing during the winter months. The Water Distribution System is applicable to domestic, industrial, recreational and institutional water distribution systems including water transmission and distribution mains and service connections. The Water Distribution System has applications in specific terrain and climatic conditions such as high bedrock, high groundwater table and permafrost. The Water Distribution System may, in specific terrain and climatic conditions, use uninsulated or insulated water mains and service connections, but without heat tracing or water bleeding in any case. The Water Distribution System is applicable to single and multiple complex distribution pipe systems arranged as parallel or looped, or combination of both arrangements.

Abstract: A pressure differential motor control system for controlling a motor of a high volume low pressure (HVLP) spray system via a pressure differential. The pressure differential motor control system has an outlet fitting connected to a turbine assembly, and a pressure switch adapted to be activated by a pressure differential from the outlet fitting. The outlet fitting has a first section connected to the turbine assembly, a mid section featuring low and high pressure ports, a second section connected to a quick coupler hose and spray gun, and a venturi defined through the outlet fitting. The low pressure port is in communication with the venturi, and the high pressure port is in communication with the input side of the outlet fitting. The pressure switch is activated by a pressure differential from the low and high pressure ports of the outlet fitting, thereby sending a signal to a motor controller for controlling a motor of the turbine assembly.

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: The invention relates to improvements in compressors and, in particular, to improvements in a method of controlling centrifugal compressors to maximise their efficacy. The compressor has an impeller mounted on a shaft supported by an active magnetic bearing unit and is driven by a variable speed motor at a rotational speed under normal on-load conditions at a calculated pre-surge speed for the required delivery pressure. The actual rotational speed and delivery pressure of the compressor is repeatedly measured and recorded at high frequency. The compressor is allowed to surge periodically after a preset re-calibration time and the compressor is put into a surge recovery cycle when surge is detected, during which the compressor is off-loaded and the rotational speed reduced.

Abstract: A method and apparatus for determining a fluid level and/or output flow during operation of a centrifugal pump, are provided, which may be used for production of gas and/or oil from a well, and include a vector feedback model to derive values of torque and speed from signals indicative of instantaneous current and voltage drawn by the pump motor, a pump model which derives values of the fluid flow rate and the head pressure for the pump from torque and speed inputs, a pumping system model that derives, from the estimated values of the pump operating parameters, an estimated value of fluid level and other pumping system parameters. Controllers responsive to the estimated values of the pumping system parameters control the pump to maintain fluid level at the pump input, near an optimum level, or within a safe operating range and/or output flow from the pump.

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 control of a pressurized air supply system for a motor vehicle. In a supply condition, the air compressor is driven by the drive motor and connected to a compressed air system of the motor vehicle such that compressed air is supplied to the compressed air system. In a non-supply condition, the compressor is not driven and/or connected to the compressed air system. The switching of the supply or non-supply condition results from a comparison of at least one switch pressure value with a pressure in the compressed air system and the topography of the stretch of road on which the vehicle is travelling, which includes the profile of the path which the vehicle must cover within a period of time and/or path distance to a given destination.

Abstract: Systems and methods for compensating for pressure increase which may occur in various enclosed spaces of a pumping apparatus are disclosed. Embodiments of the present invention may compensate for pressure increases in chambers of a pumping apparatus by moving a pumping means of the pumping apparatus to adjust the volume of the chamber to compensate for a pressure increase in the chamber. More specifically, in one embodiment, to account for unwanted pressure increases to the fluid in a dispense chamber the dispense motor may be reversed to back out piston to compensate for any pressure increase in the dispense chamber.

Abstract: An auto-stop air pump has a housing, a blower and an auto-stop device. The housing has an upper chamber, a lower chamber, a main inlet and an outlet. The upper chamber and the lower chamber communicate with each other. The main inlet and the outlet are formed through the housing respectively and communicate with the upper chamber. The blower is mounted in the housing and has a motor connected to a dual-sided impeller. The auto-stop device is mounted in the housing and has a shell, a film, a micro switch and an actuating unit. The film and the micro switch are mounted in the shell. The actuating unit is mounted movably through the shell. Owing to deformation of the film by pressure, the film presses the micro switch to close the micro switch so the air pump can stop working automatically.

Abstract: A representative mechanical draft system for drawing exhaust gasses from a chimney includes: an exhaust fan assembly having: a housing defining a chamber and having opposing openings, the opposing openings having a centerline extending therebetween, a first of the openings being operative to intake a flow of gasses, a second of the openings being operative to exhaust the flow of gasses from the chamber; and a centrifugal fan having a motor and an impeller, the motor being mounted external to the housing, the impeller being positioned within the chamber, a rotational axis of the impeller being inclined with respect to the centerline extending between the openings of the housing.

Abstract: A method for controlling a constant-pressure fluid enables an inverter with a build-in controller to control rotation speed of a pump to achieve constant-pressure control thereof. In the control method, a pressure feedback value of output flow of the pump is measured and is compared with a pressure reference value to produce an error pressure value. Afterward, an operation condition of the pump, such as an abnormal handling condition, a deceleration standby handling condition, or an acceleration condition, is determined according to the pressure error value to shut down or re-start up the pump after a delay time. Hence, the control method can avoid frequently starting up or shutting down the inverter. Therefore, the power consumption and the operation cost are reduced. The use life of the pump prolongs and constant-pressure control for the pump can be implemented.

Abstract: A linear compressor control system includes an electronic circuit controlling an electric motor that drive a piston of the compressor, such that the motor is operated intermittently with an on-time (tL) and an off-time (tD) to keep the compression capacity of the compressor substantially constant. The compressor is associated with a closed cooling circuit having an evaporator and a condenser. The off-time (tD) is shorter than the time necessary for the evaporation pressure (PE) in the evaporator and the condensation pressure (Pc) in the condenser to equalize each other after the compressor has been turned off.

Abstract: There is provided an apparatus for controlling an electric compressor, which can actuate the electric compressor rapidly through a simpler and lower-cost configuration while achieving reduction in weight, cost, and assembling time of the electric compressor. In the case where a pressure difference between the inlet side and the outlet side of the compressor body is present when a motor of the electric compressor is actuated, the motor is actuated at a number of revolutions lower than that in the normal mode. Thereby, even if a refrigerant has been liquefied on the outlet side of the compressor body, for example, the motor can be actuated by performing such action as to push out the liquefied refrigerant. In this case, the number of revolutions of the motor is increased by being changed stepwise or linearly, by which the number of revolutions of the motor is caused to reach a required number of revolutions as early as possible while surely performing the actuation.

Abstract: A controller (30) for operating a pump associated with a liquid supply system. The controller includes a pressure unit comprising a housing (34a, 34b, 34c) having a liquid inlet (98) and a liquid outlet (39, 130). A biased (42) diaphragm (40) within the housing acts against liquid pressure within the housing between the inlet and the outlet. A control circuit (50) which includes a Hall effect sensor is mounted on the housing and is responsive to movements of the diaphragm (40) via a magnet (80) associated with the diaphragm. Thus the Hall effect sensor generates signals related to pressures within the housing from which a rate of pressure change is determined. A threshold pressure value at which the control circuit (50) is operative to switch on the pump is varied in dependence upon the rate of pressure change.

Abstract: A system and method is provided for monitoring a system pressure to infer whether a high pressure cut out (HPCO) switch has opened disabling a heating, ventilating, and air conditioning (HVAC) compressor. A system and method are also provided for determining whether to disable the HVAC compressor based on a status of a low pressure cut out (LPCO) switch, an ambient temperature, and system mode state. The systems and methods may be used interchangeably with the appropriate adjustments to decision limits, such as where the LPCO may be monitored to infer status and the HPCO status may be directly used with temperature and system mode state.

Abstract: Pump apparatus and method. The pump can include a valve assembly and a diaphragm. In some embodiments, the diaphragm can include a convolute that can deform in order to increase a volume of a pumping chamber to provide an internal fluid bypass when a pressure in the pumping chamber exceeds a bypass pressure. In some embodiments, the pump can include a fluid reservoir at least partially defined by a wall with a flow-restrictive conduit in fluid communication with an outlet chamber. A shut-off switch can include an actuator in fluid communication with the fluid reservoir. The fluid reservoir and the flow-restrictive conduit can substantially isolate the shut-off switch from pressure pulses in the outlet chamber.

Abstract: A fluid transporting device is provided with a pump chamber that has a pump function for sucking and discharging a fluid, and is filled therein with the fluid, a casing unit which forms one portion of a wall surface of the pump chamber, a diaphragm which is formed by a conductive polymer film that is subjected to electrochemomechanical expansion and contraction, and forms one portion of the wall surface of the pump chamber, an electrolyte chamber that contains an electrolyte therein, with one portion of the electrolyte being made in contact with the diaphragm, a power supply that applies a voltage to the diaphragm, and a pressure maintaining unit that maintains a pressure to be applied to the diaphragm.

Abstract: A velocity-pressure control apparatus of a hydraulic machine includes a pressure command generator, a pressure sensor, a pressure controller, a velocity command generator, a velocity limiter, a switch, a comparator, a velocity sensor, and a motor driver. The pressure controller receives a pressure compensation signal composed by the pressure command generator and the pressure sensor. The velocity limiter receives a compensation velocity signal from the pressure controller and a predetermined velocity signal from the velocity command generator and outputs a corresponding limiting velocity command signal to the switch. The comparator controls the velocity-pressure control apparatus to work at a velocity control mode when the pressure compensation signal is a positive signal or a null signal, and controls the velocity-pressure control apparatus to work at a master pressure control and slave velocity control mode when the pressure compensation signal is a negative signal.