Abstract: A motor driving apparatus is applied to a fan and motor mechanism and a voltage supply unit. The motor driving apparatus includes a motor driving unit, a voltage division resistor, a first resistor, a first switch unit, a second resistor, a second switch unit, a third resistor, a third switch unit, a transistor switch, and a pulse width modulation unit. The first switch unit, the second switch unit, and the third switch unit are configured to select the rotational speed upper limitation of the fan and motor mechanism for suppressing noise.

Abstract: Provided is a system for transporting an oil sand slurry, comprising a pump, upstream and downstream lines, a shaft connectable to the pump, a driving mechanism driving the pump and a regulator for regulating the torque applied to the shaft between positive and negative torque modes, to pump the slurry at higher or lower flow rates. Also provided is a method comprising pumping the slurry through a pipeline using a pump driven by a motorised shaft and adjusting the flow rate of the slurry by varying the torque applied to the motorised shaft between positive and negative torque modes. The oil sand slurry transportation system and method enable positive head (regular pump action) for normal and high flow rates and negative head (pump brake action) for low flow rates, which reduces system energy loss, pipeline wear, vapor breakout and sanding off.

Abstract: Hydraulic pumps/motors are used to convert between rotational motion/power and fluid motion/power. Pressure differential is achieved across the pump/motor by applying torque to either aid or impede rotation which generally results in either a pressure rise or pressure drop respectively across the unit. This torque is often supplied by an electric motor/generator. Especially in positive displacement pumps/motors this pressure differential is not a smooth value but rather it contains high frequency fluctuations known as pressure ripple that are largely undesirable. With thorough analysis it can be discovered that these fluctuations occur in a predictable manner with respect to the position (angular or linear) of the pump/motor. Using a model that contains this information, a feed-forward method of high-frequency motor torque control is implemented directly on the hydraulic pump/motor by adding to the nominal torque, a model-based torque signal that is linked to rotor position.

Abstract: System and methods are provided for reducing vibration in server or data storage units. An anti-vibration system according to the present invention includes one or more disk drives and one or more fans in a defined area, and a controller which is configured to control operation of each of the one or more fans. A nominal speed setting and a speed range are determined for the one or more fans, either commonly or independently with respect to each, and the fans are caused to be driven in accordance with the determined speed setting and speed range. As a result the occasions in which individual fan speeds are coincident with fixed frequency sensitivities for each disk drive are substantially minimized.

Abstract: A power supply circuit includes a connector for a fan, a speed adjusting circuit, a speed feedback circuit, a control module, first and second power sources, and a switching module. The speed adjusting circuit is connected to a modulation pin of the connector. The speed feedback circuit is connected to a speed pin of the connector. The control module receives a speed signal from the fan through the speed feedback circuit and outputs signals correspondingly. The switching module selects the first or the second power source to supply power for the fan according to the signals from the control module.

Abstract: A hot water feeder in which a solar heat collector is used. The feeder has a first heat exchanger for heating a heat medium by solar heat, a second heat exchanger for heating water in a hot-water tank by the heated heat medium, and a heat exchange volume determination unit. The heat exchange volume determination unit calculates the flow rate of the heat medium circulating between the first and second heat exchangers on the basis of the detected temperature of the heat medium fed to the first heat exchanger and the rotational speed of a heat medium circulation pump, and calculates the heat exchange volume on basis of the flow rate and the temperature difference between the detected temperatures.

Abstract: An electrically-operated hydraulic work machine drives an actuator with a hydraulic pump driven by an electric motor and exercises load sensing control by controlling the rotation speed of the electric motor. The useful life of an electrical storage device, which is an electrical power source for the electric motor, is increased by suppressing the horsepower consumption of the hydraulic pump. This prolongs the operating time of the electrically-operated hydraulic work machine, and reduces the size of the electric motor. A controller exercises load sensing control over a variable displacement main pump by controlling the rotation speed of the electric motor, and provides the main pump with a torque control device that reduces the delivery rate of the main pump when the delivery pressure of the main pump increases, or provides the controller with a control algorithm that performs the same function as the torque control device.

Abstract: Embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, and a controller in communication with the motor. The controller determines a first motor speed, obtains a reference flow rate, determines a present flow rate, and determines a present power consumption. The controller calculates a difference value between the reference flow rate and the present flow rate, and uses at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value. The controller attempts to drive the motor at the second motor speed until reaching a steady state condition.

Abstract: A speed pick-up ring includes a main body having a plurality of targets and defining a plurality of notches. Each notch is disposed between adjacent targets. Each notch includes a base wall, a first sidewall and an oppositely disposed second sidewall. The base wall includes a convex portion. A fluid device includes a housing and a variable reluctance speed sensor engaged to the housing. The fluid device further includes a speed pick-up ring disposed within the housing. The speed pick-up ring includes a main body having a plurality of targets and defining a plurality of notches. Each notch is disposed between adjacent targets. Each notch includes a base wall, a first sidewall that is generally concave and an oppositely disposed second sidewall that is generally concave. The base wall includes a convex portion.

Abstract: A method of controlling an electric compressor of the present invention, comprises the steps of: setting a specified constant rotating speed as a target rotating speed (Rt) of a DC motor (103) (S1); obtaining an actual measurement rotating speed (Rm) which is a measurement value of a rotating speed of the DC motor (103) (S2); adjusting a duty ratio of driving electric power of the DC motor (103) so that the actual measurement rotating speed (Rm) matches the target rotating speed (Rt) (S3); and newly setting the target rotating speed based on a change in the duty ratio (S4).

Abstract: A fan rotation speed control system for controlling rotation speed of a fan is provided. The system has: a fan rotation speed controller, coupled to the fan, for receiving a signal value to produce a driving voltage to the fan and detecting an actual rotation speed of the fan; and a master controller, coupled to the fan rotation speed controller, for providing the signal value and recalculating the signal value by comparing the actual rotation speed with a target rotation speed.

Abstract: A fan system includes a motor, a rotatable hub, and a plurality of fan blades. The motor is coupled with the hub by a hollow drive shaft, such that the drive system of the fan system is gearless. The motor is controlled by a PFC-based control module, which is in communication with sensors that are configured to sense parameters associated with operation of the fan system. The control module is configured to react in certain ways to certain conditions detected by the sensors, such that the fan system uses feedback-based control algorithms. A remote control panel is in communication with the control module. The remote control panel is operable to display fault conditions detected by the sensors. Blade retainers prevent fan blades from falling when a fan blade breaks free from the hub. Pins prevent the hub from falling when the hub breaks free from the rotor.

Abstract: A fan control system for a fan on a motherboard includes an I/O controller installed on the motherboard and a control circuit electrically connected to the I/O controller. The fan includes a motor and a rotation speed detecting chip. The I/O controller outputs a rotation speed control signal and a pulse width modulation (PWM) signal. The rotation speed detecting chip detects a rotation speed of the fan, and outputs a rotation speed feedback signal according to the rotation speed of the fan. The I/O controller receives the rotation speed feedback signal, and adjusts a duty cycle of the PWM signal accordingly to change the rotation speed of the fan. The control circuit receives the rotation speed control signal, and outputs a fan driving signal accordingly. The motor receives the fan driving signal, and drives the fan to rotate in a direction according to the fan driving signal.

Abstract: A system according to the principles of the present disclosure includes a pump control module and a pump diagnostic module. The pump control module commands a water pump to switch between on and off, wherein the water pump circulates coolant through an engine when the water pump switches on as commanded. The pump diagnostic module diagnoses a fault in the water pump based on a change in a crankshaft speed of the engine when the water pump is commanded to switch between on and off.

Abstract: An apparatus for tuning pump speed at an optimal or desired speed using an automated method is disclosed. The apparatus includes a vacuum pump connected to a chamber for evacuating gas from the chamber. A sensor measures one or more characteristics, such as pressure, of the gas in the chamber. The measured characteristic is compared to a predetermined value. The speed of vacuum pump is adjusted based on the comparison until it falls in a desired range.

Abstract: Methods, systems, and techniques for structuring, operating, and/or controlling a variable fluid flow system of a machine are provided. In various embodiments, a supplemental pump and/or an electric motor can be leveraged in combination with the existing components of a machine, such as the main fluid pump of the machine.

Abstract: A fan assembly comprising an air inlet, at least one air outlet, an impeller, a motor for rotating the impeller to draw air through the air inlet, at least one heater assembly, and a user interface for allowing a user to select a speed setting for the motor from a user selectable range of speed settings, and for allowing a user to select one of a first and second operational mode of the fan assembly. A rotational speed of the motor is set depending on the user selected speed setting, and is selected from a first range of values when the first operational mode of the fan assembly has been selected, and from at least one second range of values when the second operational mode of the fan assembly has been selected, with each value within each of the range of values being associated with a respective speed setting.

Abstract: A fuel supply system has an in-tank module. The in-tank module is provided with a pump, a filter, a pressure regulator and a pressure sensor detecting a fuel pressure. The pressure sensor is disposed on or at a vicinity of the fuel pump so that the pressure sensor easily detects a pulsation component due to the pump. A fuel pump controller includes a speed detection module which detects the rotation speed of the fuel pump based on a cycle of the pulsation component of the pressure detected by the pressure sensor. Thus, the rotation speed of the fuel pump can be indirectly detected by means of the pressure sensor.

Abstract: The present invention provides a pumping system for moving water of a swimming pool, including a water pump and a variable speed motor. In one example, a target volume amount of water and an operational time period is provided, and the operational time period is altered based upon a volume of water moved. In another example, operation of the motor is altered based upon the volume of water moved. In addition or alternatively, a target flow rate of water to be moved by the water pump is determined based upon the target volume amount and a time period. In addition or alternatively, a plurality of operations are performed on the water, and a total volume of water moved by the pump is determined. In addition or alternatively, an optimized flow rate value is determined based upon power consumption.

Abstract: A vehicle includes a clutch set, a tank with fluid, an auxiliary battery, an electric fuel pump, and a controller. The electric fluid pump delivers some of the fluid from the tank to a designated oncoming clutch of the clutch set. The controller calculates a predicted flow value for the oncoming clutch during the shift event, and selectively controls the speed of the pump using the predicted flow value during the shift event. The controller controls the pump using an actual flow value when the vehicle is not executing a shift event, i.e., when holding torque. The speed of the electric fluid pump is increased to a first calculated speed determined using the predicted flow value when the shift event is initiated and before filling of the oncoming clutch commences, and is reduced to a second calculated speed determined using the actual flow value when the shift event is complete.

Abstract: Disclosed is a control device of a hydraulically driven fan. The control device of a hydraulically driven fan is characterized by comprising first command value calculation means for calculating a fan speed command by a proportional term only while a difference between a target valve controlled variable and an actual valve controlled variable is not smaller than a predetermined threshold, second command value calculation means for calculating a fan speed command by the proportional term and an integral term while a difference between a target valve controlled variable and an actual valve controlled variable is smaller than a predetermined threshold, target valve controlled variable calculation means for calculating a target valve controlled variable of a control valve based on the calculated fan speed command, and control means for outputting a valve controlled variable to a control valve such that the control valve reaches the target valve controlled variable.

Abstract: Systems and methods for providing an improved strategy for controlling a variable speed water pump in a vehicle. In some embodiments, more than one water pump speed function is calculated based on values obtained from vehicle sensors, and a controller chooses among the water pump speed function results to set a water pump speed. In some embodiments, the water pump speed is increased when driveline torque is greater than a threshold amount for an amount of time that varies based on the driveline torque. In some embodiments, ambient temperature is considered while determining whether the water pump should provide full coolant flow to an auxiliary coolant loop of a trailer.

Abstract: A system for accurately and reliably controlling an electric oil pump includes a control portion adapted to control rotation speed of the motor of the electric oil pump, a regulator valve including a valve body provided with a plurality of ports, a valve spool inserted in the valve body and an elastic member adapted to apply elastic force to the valve spool, and a switch mounted on one side of the valve body including first and second contact points, wherein the control portion increases the rotation speed of the motor when the switch is on and maintains the rotation speed of the motor when the switch is off.

Abstract: A pump apparatus has a downhole pump disposed in a wellbore and has a motor at the surface, and a rod string operatively moved by the motor reciprocates the downhole pump in the wellbore. Downhole data indicative of load and position of the downhole pump is generated using surface measurements and a wave equation model having an upstroke damping factor and a downstroke damping factor. Actual fluid load lines are determined from the downhole data for upstrokes and downstrokes of the downhole pump, and calculated fluid load lines for from the strokes are determined from the distribution of the load values in the downhole data. The actual fluid load lines are compared to the calculated fluid load lines to determine if the downhole card is over or under-damped. Then, at least one of the upstroke or downstroke damping factors of the wave equation model is adjusted so that new downhole data can be generated with appropriate damping.

Abstract: A control circuit is electrically connected to at least one fan device. The fan device has a motor and generates a sensing signal. The control circuit receives a power-source signal and the sensing signal and includes a power converting unit, a control unit and a switch unit. The power converting unit receives the power-source signal and thus respectively outputs a first power-source signal and a second power-source signal according to the power-source signal. The control unit receives the first power-source signal and the sensing signal and thus generates a control signal according to the sensing signal. The switch unit receives the control signal and generates at least one switch signal according to the control signal. The fan device receives the second power-source signal and the switch signal and drives the motor according to the switch signal.

Abstract: An integrated design for dispensing lubricants and similar fluids from bulk containers incorporates a dispense valve (8), a meter (1), a hose (7), a DC powered electric pump (2), power cord (18) and adjustable fluid suction tube (5), all packaged in one portable unit The unit is capable of dispensing fluids such as standard SAE grade automotive motor oils, automatic transmission fluid, gear lube, hydraulic oil and engine coolant (antifreeze) The pump motor will shut down at completion of dispense; and emergency shut-off to be provided.

Abstract: A fan rotation speed control system for controlling rotation speed of a fan is provided. The system has: a fan rotation speed controller, coupled to the fan, for receiving a signal value to produce a driving voltage to the fan and detecting an actual rotation speed of the fan; and a master controller, coupled to the fan rotation speed controller, for providing the signal value and recalculating the signal value by comparing the actual rotation speed with a target rotation speed.

Abstract: Control device for an electric compressor and a start control method of an electric compressor that can smoothly and reliably start the electric compressor even at high temperature. Even in a high temperature state of a power transistor, a rotational speed or an acceleration rate of a motor according to the temperature is set to gradually start the electric compressor. After the commencement of the start, the temperature of the power transistor is repeatedly checked for every predetermined time to update the rotational speed or the acceleration rate of the motor, and the rotational speed or the acceleration rate of the motor is increased according to the temperature of the power transistor, thereby allowing quick start.

Abstract: A dual-powered airflow generator comprising: a primary fan motor powered from a primary power source and an auxiliary fan motor powered from a secondary power source. In one embodiment, the primary fan motor has a first drive shaft wherein operation of the primary fan motor causes a desired airflow at a design power of the primary power source. In a preferred embodiment, the auxiliary fan motor is powered from a secondary power source and has a second drive shaft mechanically coupled to the primary fan motor, wherein the auxiliary fan motor is configured to assist the primary fan motor in causing the desired airflow while the primary fan motor operates from the primary power source at a reduced power. In a preferred embodiment, the auxiliary fan motor is powered by a solar power generating device or other alternative energy source.

Abstract: A method of controlling a motor operating a pumping apparatus of a system includes determining a trip value for a parameter, floating the trip value, and monitoring the operation of the pump. Monitoring the operation of the pump includes determining a value for the parameter, comparing the value to the trip value, and determining whether the comparison indicates a condition of the pump. The method of controlling the motor also includes controlling the motor to operate the pump based on the condition of the pump.

Abstract: An apparatus for controlling an air distribution system by controlling the speed of a motor associated with a blower to maintain a rate of air flow in the system at substantially a target air flow rate. The apparatus comprises means for controlling a supplied frequency to the motor; means for providing a speed signal representative of the speed of motor; means for providing a frequency signal representative of the supplied frequency from a controller to the motor; means for providing a load signal representative of the load of the motor; means for calculating an air flow rate signal based on the speed signal and the load signal; means for controlling a supplied frequency in response to the target air flow rate signal and the calculated air flow rate signal. The apparatus can apply three different types of algorithm for controlling and compensating the motor.

Abstract: An alarm circuit includes a fan controller with a rotation speed control pin and a rotation speed detection pin, a first rectifying circuit connected to the rotation speed control pin, a switch circuit connected to the first rectifying circuit, a first indication circuit for indicating whether the fan fails to operate based on a switch signal from the switch circuit. The alarm circuit further includes a second rectifying circuit connected to the rotation speed detection pin, a comparison circuit for outputting a comparison signal after comparing a direct current signal from the second rectifying circuit with a first reference voltage and a second reference voltage, and an indication circuit for indicating whether the fan fails to operate based on the comparison signal.

Abstract: A pump system. The pump system includes a pump, a motor coupled to the pump, a sensor coupled to a power source, and a controller. The motor operates the pump. The sensor detects an electrical characteristic of the power source. The controller executes a fault check, controls the motor, detects a change in the electrical characteristic, and suspends the execution of the fault check for a predetermined period of time when the detected change in the electrical characteristic is outside of a valid characteristic range.

Abstract: A fan control system includes first and second adjacent fans, first and second motors configured to rotate the first and second fans, and a control unit configured to control rotational speeds of the first and second motors in order to control rotational speeds of the first and second fans. The first and second motors are energized such that the rotational speeds of the first and second fans reach target rotational speeds prior to increasing the rotational speeds of the first and second fans to required rotational speeds. The target rotational speeds are lower than the required rotational speeds. The first and second motors are energized such that the rotational speeds of the first and second fans reach the required rotational speeds after the rotational speeds of the first and second fans reach the target rotational speeds.

Abstract: The anti-Sudden infant death syndrome baby fan is a portable fan that can attach to a baby crib in order to provide air movement across an infant in order to prevent the likelihood of sudden infant death syndrome. The portable fan comprises a housing, foam blades, rubber mat, knob, ON/OFF switch, and battery compartment. The inclusion of foam blades is a safety design in that foam blades will not inflict any substantive injury to anyone who touches said blades while in motion, i.e. the infant. The portable fan can also be integrated into the design of a crib mobile in order to circulate air from above the crib.

Abstract: The present invention provides protection for centrifugal pumps while differentiating between dangerous operating conditions (e.g. dry running, minimum flow and runout) and/or conditions where transient conditions (e.g. closed valve operation) may occur and the protection can be revoked once the condition clears. The methodology utilizes a calculated flow value which can be mathematically determined from a calibrated closed valve power vs speed curve and/or various pump and motor parameters such as speed, torque, power and/or differential pressure or from calibrated flow curves stored in the evaluation device. The calculated flow value is then compared to threshold values of flow associated with these adverse operating conditions.

Abstract: A control method of a fan rotation speed, which controls the operation of a fan set including fans connected in series, is disclosed. The control method includes the steps of acquiring a control factor; judging whether the control factor is less than a first threshold value; executing a first control procedure when the control factor is less than the first threshold value; judging whether the control factor is greater than a second threshold value when the control factor is greater than the first threshold; executing a second control procedure when the control factor is greater than the second threshold value; and executing a third control procedure when the control factor is less than the second threshold value.

Abstract: A method of constant airflow control includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition. Also disclosed is an apparatus for conducting these control methods.

Abstract: The invention in one aspect, provides an apparatus for controlling an electric oil pump that can determine the occurrence of idling even in a region in which determination based on a load of the electric oil pump becomes difficult. The apparatus for controlling an electric oil pump according to one embodiment of the invention sets a target number of revolutions for determination tNset higher than a required number of revolutions tNreq corresponding to an operation request of the electric oil pump, and executes control of an electric motor so that the number of revolutions N of the electric oil pump approaches the target number of revolutions for determination tNset. A load (phase current Ii) of the electric oil pump is detected while executing the control of the electric motor, and the occurrence of idling in the electric oil pump is determined based on a detected pump load (Inrm, IidI).

Abstract: An HVAC system includes a heating/cooling element; an electric motor; a speed sensor; and a control device. The heating/cooling element may include a heating element, and/or a cooling element, and associated heat exchangers. The electric motor has a rotatable shaft coupled with a blower wheel for blowing air over the heating/cooling element. The speed sensor is provided for sensing a rotational speed of the motor shaft and thus the blower wheel. The speed sensor comprises a magnet coupled with the motor shaft for rotation therewith; and a coil assembly mounted concentrically over the magnet and operable to generate an alternating signal when the magnet rotates relative to the coil. The alternating signal has an electrical characteristic that is generally proportional to the rotational speed of the shaft.

Abstract: A motor controlling method and apparatus of an air conditioner are disclosed. It is checked whether or not an operation frequency of a compressor motor is the same as or greater than a certain frequency and it is also checked whether or not a detected velocity of a fan motor is the same as or lower than a certain velocity during a certain time period. If the operation frequency is the same as or greater than the certain frequency and the detected velocity is the same as or lower than the certain velocity during a certain time period, the compressor motor is temporarily stopped. Because the compressor motor operates according to operational conditions of the fan motor, an overload can be prevented.

Abstract: A compressor includes a motor driven by a controller and having a rotor and a stator, a compressing unit driven by the motor in a hermetic container in which refrigerant is filled. Driving the motor at a low rpm, the controller practices a feedback control which determines a timing of turning on/off switching elements based on a signal detecting a position of the rotor, and when the motor is driven at a high rpm, the controller practices an open-loop control which outputs a given frequency and drives the motor synchronizing with the given frequency. This structure achieves a compressor working with a fewer noises in PWM driving.

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 pump unit includes a pump, a motor configured to drive the pump, a control device communicating with the motor and a pressure detection device configured to detect a pressure of a fluid discharged from the pump. The control device is configured to control the motor, so that a pressure detected by the pressure detection device becomes relatively equal to a target pressure. The control device is further configured to determine an estimated pressure of the fluid discharged from the pump. The control device determines whether or not an abnormality occurs based at least one of the following: a detected pressure, a difference between the target pressure and the detected pressure and/or a difference between the detected pressure and the estimated pressure.

Abstract: To provide an operation control device for a vacuum pump and a method for stopping the operation of the vacuum pump that make it possible to effectively remove products, resulting from solidification and liquefaction of gas in a casing and possibly hindering the rotation of a pump rotor, so that the vacuum pump may be started normally. An operation control device 10 for a vacuum pump having a pump rotor 1 disposed in a casing 2 for free rotation includes a pump rotor control section 15 for controlling the rotation of the pump rotor 1. The pump rotor control section 15 has a function to, after a pump stop action has been taken, rotate the pump rotor 1 in forward and/or reverse directions according to a predetermined timing pattern and then stop the pump rotor 1.

Abstract: A rotating speed adjustment circuit for a heat dissipation fan includes a first node, a second node, a reception end for receiving a first control signal, a first resistor coupled to a voltage source and the first node, a second resistor coupled to the first node and the second node, a third resistor coupled to the second node and a ground end, a capacitor coupled to the first node and the ground end, a transistor coupled to the reception end, the second node and the ground end, an oscillator for generating an oscillating signal, and a comparator for comparing a signal of the first node and the oscillating signal, so as to output a second control signal to control a rotating speed of the heat dissipation fan.

Abstract: A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

Abstract: A method for controlling a drive unit mechanically connected to a reciprocating linear-motion double-acting pump includes the use of speed-regulating control during the phase in which the piston is moving in just one direction, ascent (109) or descent (102), and the use of torque-regulating control immediately after the reversal (107, 114) of the direction of travel. The method is applicable to a control device and to a drive unit mechanically connected to a reciprocating linear-motion double-acting pump.

Abstract: There is herein described a controlled hydraulic systems for operating machinery. More particularly, there is described a controlled hydraulic system (200) comprising a variable drive ratio device (214) interposed between a prime mover (210) and a fixed displacement pump (112) for controlling the operating speed of the pump (212) and hence the output flow in the hydraulic system.

Abstract: A pumping system includes a pump for moving water. In one aspect, this is in connection with performance of an operation. The system includes a variable speed motor operatively connected to drive the pump. A value indicative of flow rate of water is determined and the motor is controlled to adjust the flow rate indicative value toward a constant. A value indicative of flow pressure is determined and the motor is controlled to adjust the flow pressure indicative value toward a constant. A selection is made between flow rate control and flow pressure control. In another aspect, the pump is controlled to perform a first operation, and is operated to perform a second water operation. Control of operation of the pump to perform the first water operation is altered in response to operation of the pump to perform the second operation.