A liquid cooling multi-pumping unit comprising a main body and first and second pumps arranged in series is provided. During operation, cooling fluid is sucked via a cooling fluid inlet into a first fluid chamber and then into a first central chamber opening to a plurality of curved blades of a first impeller assembled in a first pump chamber. From there, the cooling fluid travels and is sucked through a fluid distribution channel into a second fluid chamber and then into a second central chamber opening to a plurality of curved blades of a second impeller assembled in a second pump chamber, before exiting through a fluid outlet. The series arrangement of the first and second pumps increases head pressure, and provides sufficient liquid flak in the case where one liquid cooling pump fails. Additionally, lower energy consumption is achieved die to the lower operating speeds required.

An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

A current generator for a swimming system may include multiple entrainment pumps that discharge a flow of water into a pool. The entrainment pumps may each have a nozzle, a venturi and an entrainment inlet. In use, the flow of water from the nozzle into the venturi causes water at the entrainment inlet to flow into the venturi along with water from the nozzle. Each entrainment pump is arranged such that the fluid that flows out of the venturi passage is directed within a main passage, and the flow from multiple venturis may be combined and may be directed at least partially against the force of gravity before that fluid is directed out of the main passage outlet and into the pool. In at least some implementations, the fluid flows for at least one foot between the venturi and the main passage outlet.

A current generator for a swimming system may include multiple entrainment pumps that discharge a flow of water into a pool. The entrainment pumps may each have a nozzle, a venturi and an entrainment inlet. In use, the flow of water from the nozzle into the venturi causes water at the entrainment inlet to flow into the venturi along with water from the nozzle. Each entrainment pump is arranged such that the fluid that flows out of the venturi passage is directed within a main passage, and the flow from multiple venturis may be combined and may be directed at least partially against the force of gravity before that fluid is directed out of the main passage outlet and into the pool. In at least some implementations, the fluid flows for at least one foot between the venturi and the main passage outlet.

A pump apparatus comprises a primary pump having a relatively low pressure fluid input and a relatively high pressure fluid output and means, associated with said primary pump fluid input, operable where the ambient pressure is insufficient substantially to prevent cavitation in the primary pump, to locally increase the pressure at said primary pump fluid input.

A pump apparatus comprises a primary pump having a relatively low pressure fluid input and a relatively high pressure fluid output and means, associated with said primary pump fluid input, operable where the ambient pressure is insufficient substantially to prevent cavitation in the primary pump, to locally increase the pressure at said primary pump fluid input.

A fuel pump system for a turbomachine engine can include a boost pump driven by an electric motor and configured to be in fluid communication with a fuel tank, a primary pump configured to be driven by a shaft connected to the turbomachine engine, wherein the primary pump is in fluid communication with the boost pump downstream of the boost pump by a boost branch, a bypass flow branch that connects the boost branch to a downstream branch that is downstream of the primary pump, the downstream branch is in fluid communication with one or more metering valves and/or one or more fuel nozzles, and a bypass valve disposed in the bypass flow branch and/or the downstream branch and configured to selectively directly fluidly communicate the boost branch and the downstream branch.

A fuel pump system for a turbomachine engine can include a boost pump driven by an electric motor and configured to be in fluid communication with a fuel tank, a primary pump configured to be driven by a shaft connected to the turbomachine engine, wherein the primary pump is in fluid communication with the boost pump downstream of the boost pump by a boost branch, a bypass flow branch that connects the boost branch to a downstream branch that is downstream of the primary pump, the downstream branch is in fluid communication with one or more metering valves and/or one or more fuel nozzles, and a bypass valve disposed in the bypass flow branch and/or the downstream branch and configured to selectively directly fluidly communicate the boost branch and the downstream branch.

Exemplary embodiments of energy efficient foam pumps and dispensers are disclosed herein. An exemplary foam dispenser included a housing, a reservoir for holding a foamable liquid, a motor, a motor shaft, and a turbine air pump. The turbine air pump is connected to the motor shaft. A cam is also attached to the motor shaft and is used for driving a liquid pump. Liquid from the liquid pump and air from the turbine air pump are mixed in a mixing chamber and dispensed through an outlet nozzle. The touch-free foam dispenser further includes a sensor for sensing an object, circuitry for receiving a signal from the sensor indicative of an object being present and circuitry for energizing the motor to dispense fluid in the form of a foam.