To design the rotor (6, 6′, 6″, 6′″, 60, 60′) as compressible in the radial direction in a fluid pump, in particular for microinvasive medical use, said rotor is configured as stretchable in its longitudinal direction (16) by push elements and pull elements acting axially on it.

A fan frame body structure includes a first frame body. The first frame body has a first upper end, a first lower end, a first frame wall and a first main flow way. The first main flow way passes through the first frame body and is formed with a first main inlet and a first main outlet respectively at the first upper end and the first lower end. A first subsidiary flow way is disposed in the first frame wall. The first subsidiary flow way is in parallel the first main flow way. The first subsidiary outlet is positioned at the first upper end of the first frame body in flush with and in adjacency to the first main inlet.

A fan frame body structure includes a first frame body. The first frame body has a first upper end, a first lower end, a first frame wall and a first main flow way. The first main flow way passes through the first frame body and is formed with a first main inlet and a first main outlet respectively at the first upper end and the first lower end. A first subsidiary flow way is disposed in the first frame wall. The first subsidiary flow way is in parallel the first main flow way. The first subsidiary outlet is positioned at the first upper end of the first frame body in flush with and in adjacency to the first main inlet.

An electric centrifugal pump includes a water pump shell, a water sealing bearing, a water pump impeller, a spring washer, an inner motor cover, a bearing pedestal, a front rotor bearing, a motor stator, a motor rotor, a shaft of the motor rotor, a rear bearing of the motor rotor, a leading impeller, a leading impeller cover, a water pump driving control panel, a controller cover and a motor shell, and an internal forced cooling system is formed by the water inlet cavity of the water pump, an axial through hole of the shaft of the motor rotor, the leading impeller, a leading impeller cavity of the leading impeller, a spiral overflowing hole of the inner motor cover, a rotor cavity, a spiral overflowing hole of the bearing pedestal and the water pump impeller which are sequentially communicated.

An electric centrifugal pump includes a water pump shell, a water sealing bearing, a water pump impeller, a spring washer, an inner motor cover, a bearing pedestal, a front rotor bearing, a motor stator, a motor rotor, a shaft of the motor rotor, a rear bearing of the motor rotor, a leading impeller, a leading impeller cover, a water pump driving control panel, a controller cover and a motor shell, and an internal forced cooling system is formed by the water inlet cavity of the water pump, an axial through hole of the shaft of the motor rotor, the leading impeller, a leading impeller cavity of the leading impeller, a spiral overflowing hole of the inner motor cover, a rotor cavity, a spiral overflowing hole of the bearing pedestal and the water pump impeller which are sequentially communicated.

A cooling device for use with circuit interrupters includes a housing structured to be coupled to a terminal of the circuit interrupter and formed with several ventilation openings, as well as a permanent magnet, a torque converter and a fan blade all contained within the housing. When the cooling device is coupled to a terminal of a circuit interrupter and current flows through the terminals of the circuit interrupter, parasitic magnetic fields are generated and induce oscillatory motion of the permanent magnet. The torque converter is coupled to the permanent magnet and converts the oscillatory motion of the magnet to rotational motion that rotates the fan blade. The fan blade is disposed near the ventilation openings of the housing so that air flow produced by rotation of the fan blade travels across the surface of the circuit interrupter terminal nearest the ventilation openings to increase convection.

A cooling device for use with circuit interrupters includes a housing structured to be coupled to a terminal of the circuit interrupter and formed with several ventilation openings, as well as a permanent magnet, a torque converter and a fan blade all contained within the housing. When the cooling device is coupled to a terminal of a circuit interrupter and current flows through the terminals of the circuit interrupter, parasitic magnetic fields are generated and induce oscillatory motion of the permanent magnet. The torque converter is coupled to the permanent magnet and converts the oscillatory motion of the magnet to rotational motion that rotates the fan blade. The fan blade is disposed near the ventilation openings of the housing so that air flow produced by rotation of the fan blade travels across the surface of the circuit interrupter terminal nearest the ventilation openings to increase convection.

A cooling device for use with circuit interrupters includes a housing structured to be coupled to a terminal of the circuit interrupter and formed with several ventilation openings, as well as a permanent magnet, a torque converter and a fan blade all contained within the housing. When the cooling device is coupled to a terminal of a circuit interrupter and current flows through the terminals of the circuit interrupter, parasitic magnetic fields are generated and induce oscillatory motion of the permanent magnet. The torque converter is coupled to the permanent magnet and converts the oscillatory motion of the magnet to rotational motion that rotates the fan blade. The fan blade is disposed near the ventilation openings of the housing so that air flow produced by rotation of the fan blade travels across the surface of the circuit interrupter terminal nearest the ventilation openings to increase convection.

A cooling device for use with circuit interrupters includes a housing structured to be coupled to a terminal of the circuit interrupter and formed with several ventilation openings, as well as a permanent magnet, a torque converter and a fan blade all contained within the housing. When the cooling device is coupled to a terminal of a circuit interrupter and current flows through the terminals of the circuit interrupter, parasitic magnetic fields are generated and induce oscillatory motion of the permanent magnet. The torque converter is coupled to the permanent magnet and converts the oscillatory motion of the magnet to rotational motion that rotates the fan blade. The fan blade is disposed near the ventilation openings of the housing so that air flow produced by rotation of the fan blade travels across the surface of the circuit interrupter terminal nearest the ventilation openings to increase convection.

A liquid pressurizing apparatus, comprises a tank provided on a device installation surface for storing liquid so that a fluid level is located above the device installation surface; and a vertical pump including a suction port connected to the tank, multi-stage impellers arranged in a vertical direction, and a discharge port for discharging the liquid passing through the multi-stage impellers. The multi-stage impellers include a first stage impeller positioned at the lowest part of the multi-stage impellers and being configured such that the liquid from the suction port flows into the first stage impeller. The first stage impeller is disposed below the device installation surface.