Patent ID: 8342829

Claim:
A multi-staged screw compressor system with a gearbox ( 90 ); a drive gear ( 95 ) located in the gearbox; and a first, second, and third screw compressor ( 60 , 70 , 80 ) that are fastened to the gearbox and coupled to the drive gear such that the first, second, and third screw compressors are all driven in common by the drive gear, wherein during operation the first screw compressor ( 60 ) compresses a flow of gaseous fluid from an inlet pressure to a first intermediate pressure, the second screw compressor ( 70 ) compresses the flow of fluid from the first intermediate pressure to a second intermediate pressure, and the third screw compressor compresses the flow of fluid from the second intermediate pressure to a final pressure, wherein the final pressure is at least thirty times the inlet pressure, and further wherein the gearbox ( 90 ) has a perpendicular mounting wall ( 91 ), a drive shaft ( 94 ) rotatably held on a horizontal axis in the gearbox and supporting the drive gear ( 95 ), and the first, second, and third screw compressors ( 60 , 70 , 80 ) are attached to the mounting wall ( 91 ) parallel with one another and cantilevered, each of the first, second, and third screw compressors having two screw rotors ( 3 , 5 ) whose axes are parallel and which have screw-shaped ribs and grooves that mesh together and a shaft pin ( 7 c ) on one of the two screw rotors that extends through an opening in the mounting wall ( 91 ) into the gearbox ( 90 ) and that supports respective driven gears ( 65 , 75 , 85 ) that each mesh with the drive gear ( 95 ), wherein the driven gears ( 65 , 75 ) of the first and second screw compressors mesh with the drive gear ( 95 ) at locations that are above the horizontal plane that runs through the rotating axis (A) of the drive gear and wherein the third screw compressor ( 80 ) is located below the first and the second screw compressors ( 60 , 70 ) and the driven gear ( 85 ) of the third screw compressor meshes with the drive gear ( 95 ) at a location that is less than 30° with respect to the vertical plane running through the rotating axis (A) of the drive gear ( 95 ) from the lowest point (T) of the periphery of the drive gear ( 95 ).