A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

Pump systems with pinch valves for surgical procedures. At least some of the example embodiments are pump systems including a stationary housing defining a front face. A tube support extends outwardly from the front face for aligning and supporting a first tube and a second tube. At least one pinch member is movable relative to the tube support by a power actuator operably coupled to the at least one pinch member and configured to have three orientations that define: a first arrangement of the pinch member relative to the tube support configured to pinch closed the first tube, a second arrangement of the at least one pinch member relative to the tube support configured to pinch closed the second tube, and a third arrangement of the at least one pinch member relative to the tube support configured to pinch closed neither the first tube nor the second tube.

Pump systems with pinch valves for surgical procedures. At least some of the example embodiments are pump systems including a stationary housing defining a front face. A tube support extends outwardly from the front face for aligning and supporting a first tube and a second tube. At least one pinch member is movable relative to the tube support by a power actuator operably coupled to the at least one pinch member and configured to have three orientations that define: a first arrangement of the pinch member relative to the tube support configured to pinch closed the first tube, a second arrangement of the at least one pinch member relative to the tube support configured to pinch closed the second tube, and a third arrangement of the at least one pinch member relative to the tube support configured to pinch closed neither the first tube nor the second tube.

A multi-piston fluid pump system includes a pump head, a motor unit, and a processor, the pump head having two or more cylinders and a piston disposed within each cylinder, the motor unit configured to provide bi-directional actuation of the pistons in each cylinder in response to control signals from the processor in order to minimize fluctuations in pressure and/or flow rate at the outlet of the fluid pump system.

A pumping module is positionable within a pump housing for pumping fluid into a wellbore. The pumping module includes a cylindrical housing with an inlet end and an outlet end, an inlet cap positioned on the inlet end of the cylindrical housing and including an inlet formed through the inlet cap, and an outlet cap positioned on the outlet end of the cylindrical housing and including an outlet formed through the outlet cap. A shaft is rotatable with respect to the cylindrical housing, and a rotor is positioned within the cylindrical housing and rotatable by the shaft to push fluid through the cylindrical housing.

A cooling circuit comprises a refrigerant compressor incorporating a suction port and a pressure chamber incorporating a pressure port, a condenser arranged downstream of the pressure port, a fluid collecting chamber in which a reservoir of refrigerant is formed, an evaporator which is located between the condenser and the suction port, a feed unit which is connected at one side to the refrigerant reservoir and to the pressure chamber at the other side and which serves for supplying refrigerant from the refrigerant reservoir to the pressure chamber which incorporates a pumping unit for the refrigerant. It is proposed that in order improve this cooling circuit, the pumping unit comprise a pressure-tight closed housing which is provided with only one inlet and one outlet as access points and a pumping element which is movable for pumping the refrigerant be arranged in the pumping chamber thereof.

Automatic electric actuation of the pumping mechanism of a liquid dispenser apparatus is provided by configuring a hollow tube to cooperate with an electromagnetically driven actuator and further configuring the hollow tube to inter-fit with a stem of a liquid dispensing pump. Actuation of the actuator may, for example, drive the pump stem downwardly to cause a pumping action. Suitable actuators include, for example, solenoids, voice coil actuators and stepping motors.

Automatic electric actuation of the pumping mechanism of a liquid dispenser apparatus is provided by configuring a hollow tube to cooperate with an electromagnetically driven actuator and further configuring the hollow tube to inter-fit with a stem of a liquid dispensing pump. Actuation of the actuator may, for example, drive the pump stem downwardly to cause a pumping action. Suitable actuators include, for example, solenoids, voice coil actuators and stepping motors.

A system may include a magnetic shape memory (MSM) element having a long axis that extends from a first end of the MSM element to a second end of the MSM element. The system may further include a first solenoid, where a longitudinal axis of the first solenoid is positioned at a first angle relative to the long axis of the MSM element. The system may also include a second solenoid, where a longitudinal axis of the second solenoid is positioned at a second angle relative to the long axis of the MSM element and at a third angle relative to the longitudinal axis of the first solenoid, where the longitudinal axis of the first solenoid and the longitudinal axis of the second solenoid are not parallel.