Reconfigurability of engines: A kinematic approach to variable compression ratio engines

The variable compression ratio (VCR) engine has become an opportunity to overcome the new consumption and emissions laws. Researchers believe that the VCR engine can unite both efficiency and performance. Thus, it is applied a methodology based on Tsai (2000) and Yan (1998) in order to investigate the opportunities for the development of VCR engines. A patent survey was conducted analyzing 1163 patents and resulting in 127 different VCR engine designs. Based on that survey and comparing with several authors, this paper proposes an enhanced classification of the VCR engines. The kinematic chains from all classes of VCR engines are analyzed in order to investigate the topological and structural characteristics which are compared with previous works from Freudenstein and Maki (1983) and Tsai (2000). This information is used to discuss both the reconfigurability and the potential for innovation of VCR engines.