PURPOSE: To recover power by providing at least one variable cycle type mechanical supercharger down the stream and operating it in compression cycle at low speed range and in expansion cycle at high speed range, in an engine with at least two supercharger provided in series.
CONSTITUTION: Air intake passages 2 and 3 on each bank of a V-type engine 1 are connected to a common air intake passage 6 through manifolds 4 and 5, respectively, and a turbosupercharger 10 and a mechanical supercharger 11 are provided in series in the common air intake passage 6. The mechanical supercharger 11 down the stream is of byaxial screw type of Lysholm and the top end of the drive shaft of the supercharger 11 is provided with a variable pulley 24 that its diameter varies according to centrifugal force. The rotation of the pulley is transmitted to a crank shaft 29 through a belt 25, a second variable pulley 26, an electro-magnetic clutch 27, etc. In an area where the discharge pressure of the turbosupercharger is higher than that of the mechanical supercharger at high engine speed, the mechanical supercharger 11 is used as an expander for power recovery.
HATAMURA KOICHI
SASAKI JUNZO
