A circulator is described that is configured to circulate liquids such as water, chemical mixtures, suspensions and the like. The circulator has an oscillation shaft disposed within, for example concentrically disposed within, a support tube that is used to mount the circulator to a support structure. Locating the oscillation shaft within the support tube makes the circulator more compact, achieves better alignment of the oscillation shaft and the support tube, and makes the circulator stronger compared to a circulator where the oscillation shaft is not disposed within a support tube. In one embodiment, the circulator can be used to create a continuous flow of water in a body of water including around marinas, areas around docks, and waterfronts.

A water pump with an impeller driven by an electrical machine comprising a housing cap and a volute with an inlet) and an outlet and a boot hosting a stator and a rotor of the electrical machine, wherein the rotor is mounted on a fixed shaft in the water pump having a bushing rotatable mounted on the shaft.

A water pump with an impeller driven by an electrical machine comprising a housing cap and a volute with an inlet) and an outlet and a boot hosting a stator and a rotor of the electrical machine, wherein the rotor is mounted on a fixed shaft in the water pump having a bushing rotatable mounted on the shaft.

In one aspect, a pump is provided comprising a motor configured to rotate a shaft that is operably coupled to an impeller. The impeller is housed within a fluid chamber having an inlet and a discharge in fluid communication with the inlet. The fluid chamber further includes an outlet in a top portion thereof for venting air within the fluid chamber when the impeller is rotated by the motor. In other forms, a pump assembly is provided with an internal float switch integrated into the pump housing.

In one aspect, a pump is provided comprising a motor configured to rotate a shaft that is operably coupled to an impeller. The impeller is housed within a fluid chamber having an inlet and a discharge in fluid communication with the inlet. The fluid chamber further includes an outlet in a top portion thereof for venting air within the fluid chamber when the impeller is rotated by the motor. In other forms, a pump assembly is provided with an internal float switch integrated into the pump housing.

An electric submersible pump (ESP) with reduced vibration is provided. In an implementation, an ESP section has radial bearings placed at shaft locations of reduced vibration to reduce wear. The locations of reduced vibration are selected to avoid areas of high vibration and vibrational waves that reinforce each other due to structure resonance and natural excitation frequencies. In an implementation, a radial bearing is positioned at a node of reduced vibration of a standing vibrational wave. In an implementation, a succession of multiple radial bearings are spaced at different intervals from each other to avoid conventional even spacing of the bearings that causes standing waves, resonance waves, and vibrational waves at natural excitation frequencies. In an implementation, a span between adjacent radial bearings is selected to spare other adjacent bearings at different spans the effects of vibrations that may extend over a range of excitation frequencies in the ESP section.

An electric submersible pump (ESP) with reduced vibration is provided. In an implementation, an ESP section has radial bearings placed at shaft locations of reduced vibration to reduce wear. The locations of reduced vibration are selected to avoid areas of high vibration and vibrational waves that reinforce each other due to structure resonance and natural excitation frequencies. In an implementation, a radial bearing is positioned at a node of reduced vibration of a standing vibrational wave. In an implementation, a succession of multiple radial bearings are spaced at different intervals from each other to avoid conventional even spacing of the bearings that causes standing waves, resonance waves, and vibrational waves at natural excitation frequencies. In an implementation, a span between adjacent radial bearings is selected to spare other adjacent bearings at different spans the effects of vibrations that may extend over a range of excitation frequencies in the ESP section.

A downhole tool includes an electric submersible pump to pump a well fluid to a surface of a borehole. The downhole tool includes a motor to power the electric submersible pump and a seal section to protect the motor from the well fluid. The seal section includes an elastomeric bag and a clamp at each end of the elastomeric bag to secure the elastomeric bag. The seal section includes an elastomeric bag protector secured around each clamp, wherein the elastomeric bag protector extends axially beyond a respective clamp to surround a tapered portion of the elastomeric bag above and below the clamp, and wherein the elastomeric bag protector has a sloped inner diameter that matches a profile of the tapered portion.

An inducer and a submersible pump for pumping a slurry comprising solids and viscous fluids, the inducer mountable to the pump's drive shaft adjacent to and immediately upstream of an impeller mounted on said shaft. The inducer comprises a hub, two to four inducer blades extending outwardly from and wrapping helically around the hub, the hub and the inducer blades defining a plurality of channels A trailing edge of each inducer blade is positioned snugly adjacent to and in fluidical alignment with a leading edge of a corresponding impeller blade when the inducer is mounted on the drive shaft of the pump, such that a velocity curve of the slurry is smooth as the slurry travels from a leading edge of the inducer blades to the leading edge of the impeller blades.

A variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system is provided. The method includes monitoring a pressure in the fluid system, monitoring and adjusting an operating frequency of the motor to maintain the pressure at a pressure set point, and, based on the monitored operating frequency, causing the pump to temporarily boost the pressure in the fluid system to a temporary boost set point for a first time period. The method also includes determining whether the temporarily boosted pressure in the fluid system stays above the pressure set point for a second time period and causing the pump to enter a sleep mode when the temporarily boosted pressure stays above the pressure set point through the second time period.