An electric canned coolant pump includes a drive motor comprising a split case provided as a separating can which separates a wet chamber comprising a motor rotor from a dry chamber comprising a motor stator. The separating can comprises a separating can form-fit structure. A Hall sensor is arranged on the separating can. The Hall sensor detects a position of the motor rotor in the dry chamber. The Hall sensor comprises a sensor head and Hall sensor electric connecting lines. A positioning element comprises positioning element electric connecting lines which are connected with the corresponding Hall sensor electric connecting lines. The positioning element electric connecting lines comprise a connecting body comprising a connecting body form-fit structure. The connecting body is electrically insulating and holds the positioning element electric connecting lines. The separating can form-fit structure and the connecting body form-fit structure fix the connecting body on the separating can.

An electric submersible pump (ESP) can include a shaft; an electric motor configured to rotatably drive the shaft; a housing; a stack of diffusers disposed in the housing; impellers disposed in the housing and operatively coupled to the shaft; and a proximity sensor operatively coupled to the housing.

An electric fluid pump and method of regulating flow of liquid therethrough is provided. The pump has an electric motor including a stator and a rotor, wherein the rotor is supported for rotation to drive an impeller that is fixed thereto for rotation to pump coolant from a fluid inlet to a fluid outlet. A controller is in operable, closed loop communication with the electric motor, and the impeller is operable to rotate in a first rotary pumping direction and an opposite second rotary pumping direction in response to a signal from the controller. The first rotary pumping direction produces a first positive flow rate of coolant outwardly from the fluid outlet and the second rotary pumping direction produces a second positive flow rate of coolant outwardly from the fluid outlet, with the first positive flow rate being greater than the second positive flow rate.

An electric submersible pump (ESP) can include a shaft; an electric motor configured to rotatably drive the shaft; a housing; a stack of diffusers disposed in the housing; impellers disposed in the housing and operatively coupled to the shaft; and a proximity sensor operatively coupled to the housing.

An electric pump includes: a motor that drives a pump; and a control unit to which an input signal for driving the motor is input from an external device, which outputs a drive signal based on the input signal, and which outputs a pulse signal indicating a rotation state of the motor to the external device, in which the control unit is configured to change both of a frequency and a duty ratio of the pulse signal so as to be capable of discriminating whether the motor is in a drive state or a stop state and between a plurality of states of the motor in the stop state.

Apparatus, including a pumping system, is provided featuring a pump and a control circuit. The pump has an impeller housing configured with a slit at the top for trapped air to leave the impeller housing once the pump has been submerged. The control circuit is configured to cycle the pump on and off for a predetermined number of cycles so that the trapped air will float to the top and be expelled out the slit when the pump is cycled off. The control circuit is configured to leave the pump on after the predetermined number of cycles.

Systems and methods of restarting a downhole pump for pumping downhole fluid and located in a wellbore that include determining a pump reverse rotational frequency of a downhole pump caused by downhole fluid flowing in a downhole direction using a phase locked loop. A pump motor is driven at a motor reverse rotational frequency matching the pump reverse rotational frequency. The pump motor is then driven to accelerate the pump reverse rotational frequency and thereby pump the downhole fluid in an uphole direction. The pump motor is then driven to decrease the pump reverse rotational frequency while continuing to pump the downhole fluid in the uphole direction. The pump motor is then driven to change the rotation of the downhole pump to a forward rotation at a pump forward rotational frequency to pump the downhole fluid in the uphole direction.

A method for controlling air volume including: inputting a target air volume into the microprocessor control unit of the motor controller; starting a motor by the motor controller under a torque to enable the motor to work in a steady state; recording the rotational speed in the steady state, and establishing a functional relation formula Q=F (T, n, V) to calculate an air volume in the steady state; comparing the target air volume with the calculated air volume; re-recording a steady rotational speed after the motor falls on a new steady state under an increased or reduced torque, and recalculating the air volume in the new steady state; and repeatedly adjusting the torque until the calculated air volume is equal or equivalent to the target air volume.

Methods and systems for detecting and correcting improper operation of a compressor in a refrigeration system and/or an HVAC system include a component level detection and prevention and a system level detection and prevention. The system level detection and prevention can be a backup or a confirmation of the component level detection and prevention. The component level detection and prevention can detect and prevent improper compressor operation within a predetermined time so that the compressor's operation period in an improper direction can be minimized, thereby minimizing wear and damage to the compressor.

Between the lower stage in respective phases of inverter circuit and the negative potential side, shunt resistors are inserted for respective phases. The potential differences across shunt resistors occurring by current flowing through shunt resistors are amplified by amplifier unit. From the output of amplifier unit, current detecting unit detects current of each phase flowing through motor formed by a sensorless brushless DC motor. Rotation detecting unit calculates the rotation speed and position of motor based on the current detected by current detecting unit. This structure makes it possible to directly detect solely the current flowing through the windings of motor. Therefore, it becomes possible to accurately detect the current of the motor windings, and the ventilation device can maintain the ventilation air volume from a small air volume to a large air volume always at a constant value.