BigPatents India

In a booster-type gas compressor, an electric motor in a motor case drives a crank shaft integrally connected to a driving shaft. The crank shaft is coupled to a piston rod extending perpendicular to the crank shaft and having a piston at the upper end. Rotation of the crank shaft allows the piston up and down. A compressed gas from a compressed-gas flow path is fed to a compressing chamber above the piston and further compressed by the piston. A bypath conduit connects the compressed-gas flow path to the motor case to keep pressure in the crank case to more than atmospheric pressure.