Extensive experimental and numerical investigations with respect to mass balance unit (MBU) were reported to improve the vibration and acoustic performance for inline 4-cylinder engine due to unbalanced inherent secondary order inertial forces. Design of gear-driven MBU with two parallel shafts and two gear pairs which was positioned beneath the crankshaft would be described in the paper. For the sake of compact package and reliable design, the driving gear ring of the system was shrink fitted onto the crankweb, and issues such as lubrication, strength, assembly were taken into account during design process. As a result, 93.66% of 2nd order mass force balance was achieved and2nd vibration level of engine was decreased remarkably. However, acoustical behavior was deteriorated due to gear impact and rattle at the engagement. Extra efforts were paid to solve the unpleasant noise through internal and external excitation optimizations. In the end thanks to good damping property of the material, applying resin material to two driven gears in the original MBU made amazingly improvement in terms of both sound level and sound quality, and the radiated sound pressure was even lower than the engine without MBU, which also indicated that this smart design complies with engineering requirements for series production.
Design of Engine Gear-Driven Mass Balance Unit and NVH Performance Optimization
Sae Technical Papers
SAE 2012 World Congress & Exhibition ; 2012
2012-04-16
Conference paper
English
Design of Engine Gear-Driven Mass Balance Unit and NVH Performance Optimization
British Library Conference Proceedings | 2012
|Polymer Gear Development to Improve Efficiency and NVH Performance of an Engine Mass Balance System
British Library Conference Proceedings | 2011
|Polymer Gear Development to Improve Efficiency and NVH Performance of an Engine Mass Balance System
SAE Technical Papers | 2011
|Polymer gear development to improve efficiency and NVH performance of an engine mass balance system
Automotive engineering | 2011
|Development of resin gear balance shaft system for 2AZ-FE engine
Online Contents | 2002
|