Abstract: A water-cooled pump motor for delivering potable water in a demand system includes a centrifugal pump including a volute and an impeller in the volute, an electric motor driving the impeller having a hollow rotor shaft, a rotor on the shaft, bearings supporting the rotor shaft, a stator coaxially outward of the rotor, two water impervious liners, one located within the stator and the other coaxially outside the rotor, the liners being spaced to define a cylindrical passageway across the rotor and a cooling and lubricating water passageway for water to flow through the motor including flow from the impeller between the rotor shaft and the bearings, across the cylindrical passageway and through the hollow rotor shaft back into the volute.

Abstract: A cooling system employing Micro Electro Mechanical System (MEMS) technology and polarization principles to move a cooling fluid over a surface requiring cooling and further employing electrohydrodynamic principles for the purpose of enhancing the heat transfer coefficient between the cooling fluid and the surface to be cooled.

Abstract: A needle holder positioning structure for a safety syringe includes a syringe with a neck portion having a top end forming a positioning projecting ring, an inner edge of a lower end of the neck portion upwardly and integrally formed with a forked elastic sleeve, with a terminus inwardly forming hook members, a bottom end of a needle holder for receiving a needle being inwardly provided with a flared hole having a distal end forming an enlarged opening, the bottom end of the needle holder being outwardly provided with a guide face, and an outer side formed with depressions corresponding to the hook members.

Abstract: A compressor is provided in which the arrangement and the position of a spring chamber, in which a coil spring biasing a main shaft is accommodated, are designed and the various designs of the compressor is possible.

Abstract: An apparatus comprises a tank, an air compressor, and a motor with an output shaft. A fan is mounted on the output shaft. A drive assembly interconnects the motor operatively with the compressor. The apparatus further includes a base structure and a shroud. The base structure is configured to support the compressor, the motor and the drive assembly on the tank. The shroud is configured to cover the compressor, the motor, the drive assembly and the base structure on the tank. The shroud has a cooling air inlet port and a cooling air outlet port. A plurality of internal wall portions of the shroud are configured to direct cooling air to flow over the motor and the compressor upon flowing through the cover from the inlet port to the outlet port under the influence of the fan.

Abstract: A modular solid-fuel rocket propellent charge has a combustion-chamber wall, a plurality of separate elements including frozen fuel or oxidizer, and respective rigid casings completely surrounding and enclosing the elements. Respective formations on the casing and on the casings directly engage each other for supporting the elements via the respective casings directly an the wall.