A new type of drive system has been designed, analyzed, patented, prototyped, and tested. The drive’s unique capabilities include the ability to vary the bottom dead center position to reduce the stroke, and simultaneously vary the top dead center position to achieve the desired compression ratio with one simple, low friction mechanism. The purpose of the concept is to reduce losses associated with operation at partial load as most engines spend a preponderance of their operating life at partial load. This paper covers the design and analysis, prototyping, and testing of the unit as an air compressor.
Engine simulation of the unit configured as a gasoline engine showed a ~30% improvement in fuel economy on a 10-mode weighted cycle and is covered in SAE 2021-01-0442, “Continuously Variable Displacement Drive for Engines Part 1, Performance Simulation.”