A method of determining a state of cooling water is provided. The method includes operating, by a controller, a driving motor of a cooling water-circulating pump that is configured to circulate cooling water at a fixed current, a fixed torque, or a fixed power. In addition, the controller is configured to calculate an average rotation speed of the driving motor for a preset first period of time during the operation of the driving motor. Whether the circulation state of the cooling water is normal is determined based on an error between the calculated average rotation speed and a preset reference rotation speed.

An electrical submersible pump assembly has pump, motor and pressure equalizer modules. A first adapter, which secures to the first module, has an external set of first adapter threads. A second adapter, which secures to the second module, has an external set of second adapter threads. A collar has an internal set of collar first threads that engage the first adapter threads, and an internal set of collar second threads that engage the second adapter threads. The collar first and second threads differ from each other, such that rotation of the collar relative to the first and second modules pulls the first and second modules toward each other. The pitches of the collar first and second threads may differ. Or, the collar first and second threads may turn in opposite directions.

A subsea pump, distinctive in that it comprises a pressure housing divided into two compartments; a compartment with pump or impellers arranged on a shaft and a compartment with motor or a stator; a diaphragm arranged sealingly between the compartments, a magnetic coupling between the compartments, through the diaphragm; and a pressure compensation system for balancing the pressure on the diaphragm of the motor or stator compartment side to the pressure on the diaphragm of the pump or impeller compartment side.

Disclosed is a pump for conveying a pump having a pump rotor rotatably supported about an axis of rotation in a pump stator in the operating state and a rotor shaft is arranged in a shaft leadthrough such that a lubricating film of a lubricating fluid formed from the pump fluid can be formed in a ring gap between the rotor shaft and the shaft leadthrough; and wherein a separation device is provided at the rotor shaft by which a predefinable quantity of an ingredient can be separated from the pump fluid by means of a centrifugal force for providing the lubricating fluid at the ring gap in the operating state, wherein a recirculation device is provided so that a gas can be recirculated with the aid of the separation device.

A supercharging device for an internal combustion engine, in particular for a vehicle, with a compressor having a compressor housing and having a compressor space in which a compressor wheel is arranged, an electric motor having a rotor and a stator, a motor housing having a motor space for accommodating the rotor and the stator, and a connection from the compressor space into the motor space in order to permit pressure equalization between the compressor space and the motor space.

A fluid pressure compensation apparatus includes a pipe, a pressure measuring device, a pressure compensating structure and a connecting mechanism. The pressure measuring device in fluid communication with the pipe. The pressure compensating structure is filled with a hydraulic fluid. The connecting mechanism is coupled to the pressure measuring device and coupled to the pressure compensating structure such that changes in pressure within the pipe measured by the pressure measuring device are mechanically transmitted via the connecting mechanism to the pressure compensating structure causing corresponding movement of the hydraulic fluid in and out of the pressure compensating structure.

A fluid pressure compensation apparatus includes a pipe, a pressure measuring device, a pressure compensating structure and a connecting mechanism. The pressure measuring device in fluid communication with the pipe. The pressure compensating structure is filled with a hydraulic fluid. The connecting mechanism is coupled to the pressure measuring device and coupled to the pressure compensating structure such that changes in pressure within the pipe measured by the pressure measuring device are mechanically transmitted via the connecting mechanism to the pressure compensating structure causing corresponding movement of the hydraulic fluid in and out of the pressure compensating structure.

A subsea fluid processing system includes an electric motor that rotates a shaft on which impellers are fixedly mounted. Diffusors are static and fixed to the pump housing. The electric motor includes a rotor surrounding the shaft and a stator that is filled with a dielectric stator fluid. The stator is sealed or canned. The inner surface of the stator which faces the rotor is canned with a canning non-metallic material. The motor, as well as bearings for the rotating shaft are lubricated and cooled with a fluid that in some cases is taken from the process fluid and some alternative source. Alternative sources include: MEG, methanol, treated seawater and untreated seawater.