Abstract:

Three-cylinder engines, which have small packaging size, have been a key player for major original design manufactures (OEMs) to meet more and more stringent fuel economy and emission regulations for internal combustion engines in the recent years. In this paper, vibration mechanism of 3-cylinders is illustrated, NVH (noise, vibration、harshness) issues associated with 3-cylinder engines are analyzed, and solutions presented by OEMs are summarized. The systematic analyses and optimizations on engine and transfer path, including crankshaft, balance shaft, dual-mode torsion vibration damper (TVD), engine mounts, and exhaust system, are applied to a 1-liter 3-cylinder turbocharged gasoline direct injection engine developed by Geely Auto. With the optimizations, the 3-cylinder engine delivers excellent NVH performance, along with good power and fuel economy, to provide superior driving experience to customers.

Key words: 3-cylinder gasoline engine, turbocharging,  noise, vibration, harshness (NVH) , balance shaft, dual mode torsion vibration damper (TVD)