Diesel Design for Turbocharging

A novel design for a two-stroke cycle diesel engine for traction purposes, having a mechanically driven scavenge blower in series with an exhaust gas turbocharger, is proposed. By driving the scavenge blower from the crankshaft, through a variable speed drive, the quantity of charge air supplied to the engine can be varied independently of engine speed. Very high torque at low engine speed is thus possible, and an ideal traction torque characteristic results. To eliminate the problems associated with high peak cycle gas pressure under these conditions, a simple variable compression ratio mechanism is incorporated.