Novel Mechanisms to Improve the Start Quality of Automotive Engines

Start-stop technology is an affordable pathway to reduce fuel con-sumption and emissions in automotive propulsion systems. We present two novel mechatronic starters. The first concept uses a two-speed starting device to crank the engine to a higher rpm prior to ignition. It is comprised of an arrangement of gears and clutches that changes the overall cranking gear ratio during the course of the start event. This allows the engine to reach nearly twice its rated pre-igni-tion rpm, making for ultra-smooth starts. The second concept is a mechatronic starter that can switch between geared and belted operation. This integrated starter with selectable geared and belted connections to the crankshaft enables a very fast, smooth start in belt-mode compared to a conventional 12V starter.