An electrical submersible well pump has upper and lower diffusers non-rotatably mounted in a housing. A rotatable impeller between the upper and lower diffusers has a bottom shroud. An outward-facing wall is on an upper end of the lower diffuser. A lower end of the upper diffuser has an inward-facing wall that fits closely around the outward-facing wall of the lower diffuser. A key mounted between the inward-facing and outward-facing walls prevents relative rotation between the diffusers. The key extends axially above an upper end of the neck and radially inward from the inward-facing wall of the upper diffuser into close proximity to the bottom shroud, creating a sand dam.

A motor controller includes a motor control part controlling a motor having a three-phase coil by a control signal, an inverter applying a drive voltage supplied from a power source to the three-phase coil based on an output signal from the motor control part, a drive voltage line supplying the drive voltage to the inverter, a common line electrically connected with a neutral point of the three-phase coil, an inductor electrically connected in series with the drive voltage line, a first capacitor between a portion between the inverter and the inductor in the drive voltage line and a ground, a second capacitor between a portion on an input side with respect to the first capacitor in the drive voltage line and the ground, and a third capacitor between the second capacitor and the ground. The common line is electrically connected between the second capacitor and the third capacitor.

The present invention relates to a centrifugal pump and a bearing retainer for the centrifugal pump. The centrifugal pump has a shaft, a bearing for supporting the shaft, and a bearing retainer for the bearing. The bearing retainer comprises a ring section adapted to surround the bearing and an elastic section adjacent the ring section, wherein the elastic section comprises multiple slits, dividing the elastic section into multiple resilient parts, wherein the multiple resilient parts are adapted to receiving and supporting the bearing, thereby creating a compression force in radial direction perpendicular to the axis of the shaft, allowing the bearing retainer to hold the bearing in a fixed position with respect to the bearing retainer.

Systems and features for improving sand control in pumps are provided. These features can be used in centrifugal pumps employed in a variety of oilfield applications, such as in electric submersible pumping systems positioned downhole in a wellbore to pump oil or other fluids. Such features include shielded anti-swirl ribs positioned in the balance chamber.

The bearing component comprises an external cylindrical member having an outer bearing surface and an inner cavity, and internal cylindrical member, arranged in the inner cavity of the external cylindrical member and substantially coaxial thereto. The external cylindrical member and the internal cylindrical member form a gap therebetween. A resilient damping feature is arranged in the gap.

The disclosure relates to an electric liquid pump, comprising a pump housing, a motor connected to the pump housing, and an impeller housed in the pump housing and driven by the motor. The pump housing is provided with an inlet port and an outlet port. The impeller has an impeller inlet at the center thereof and an impeller outlet at a peripheral side thereof. The inlet port, the impeller inlet, the impeller outlet, and the outlet port are in flow connection sequentially. The inlet port comprises a columnar first segment and a second segment extending from the first segment. The second segment is close to the impeller inlet with a mouting seat formed therein. The impeller is sleeved on a rotation shaft. One end of the rotation shaft is engaged in the mounting seat. The impeller is rotatable relative to the mounting seat. The mounting seat is partially received in the impeller inlet. A gap between the mounting seat and an inner wall of the impeller inlet is defined as a flow passage for liquid.

A strain estimation device according to an aspect of the present disclosure is a strain estimation device that estimates strain of a component provided in a fluid and includes a pressure acquisition unit that acquires a pressure signal including time-series pressure values at a predetermined position in a vicinity of the component, an estimation unit that estimates, based on the pressure signal, a strain signal including time-series strain values occurring at the component, and an output unit that outputs the strain signal. The estimation unit converts the pressure signal into the strain signal using an estimation filter determined based on a power spectral density of pressure and a power spectral density of strain occurring at the component when the pressure is applied to the position.

The invention relates to a pumping device for pumping liquids, comprising a centrifugal pump with a radially pumping pump wheel with a hollow center. A pumping device 101 is proposed to provide a device for pumping liquids with a centrifugal pump with a radially pumping pump wheel with a hollow center, said pump being equipped to remove accumulations of gas from the interior of the pump, with a centrifugal pump 110 with a radially pumping pump wheel 201 with a hollow center, a detecting device 120 for detecting the first operating parameter 510, a sensor 130 for measuring a second operating parameter 520 and a control unit 180 for controlling the centrifugal pump 110 which is connected to the pump 110, the detecting device 120 for detecting the first operating parameter 510 and to the sensor 130, During operation, the pump 110 may be assigned a value of the first operating parameter 510 at any point in time. The control unit 180 is also equipped so that it controls the operation of the pump 110 and can remove accumulations of gas from the hollow center of the pump 110 during liquid pumping operation of the pump 110 by operating the pump 110 in a first step for removal of gas such that at least the first operating parameter 510 of the pump 110 is varied over time t, so that the first operating parameter 510 assumes a series of different predetermined values, one after another, and meanwhile values of the second operating parameter 520 associated with the values of the first operating parameter 510 are recorded, local and/or global extreme values E of the previously recorded values of the second operating parameter 520 are determined in a second step for removal of gas; those values 510E of the first operating parameter 510 are determined in a third step for gas removal, these values being associated with the extreme values E of the second operating parameter 520 previously determined; in a fourth step for removal of gas, the pump 110 is operated so that it assumes one of the values of the first operating parameter 510 associated with the extreme values E of the second operating parameter 520 for a predetermined period of time T.

An apparatus for cleaning nets underwater formed from a propeller housing with a centrally disposed axis with a plurality of blades extending therefrom. An outer perimeter ring secured to an outer tip of each blade with a plurality of knuckles secured to the outer perimeter ring. Each knuckle including a curved surface constructed and arranged to be forcefully presented to the aquaculture net upon rotation of said blades for removal of growth by impact and shaking of the aquaculture net. An elastomeric hub prevents spike loads.

This refrigerant vessel component (2, 4, 7) for a refrigeration circuit (100), comprises a shell (10) extending along a longitudinal axis (X) delimiting an internal volume (V), in which circulates a refrigerant fluid (R), whereas the refrigerant vessel component (2) comprises an inner shell (20) located radially inside the shell (10) and extending on at least a portion of the circumference of the shell (10), and whereas the inner shell (20) is at least partly formed of perforated material.