Browse Publications Technical Papers 2012-01-0890

Design of Engine Gear-Driven Mass Balance Unit and NVH Performance Optimization 2012-01-0890

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.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Timing Gear Whine Noise Reduction Methodology and Application in Superchargers


View Details


Vehicle Design for Robust Driveline NVH Due to Imbalance and Runout Using a Monte Carlo Process


View Details


Vibration Transmission Analysis of Automotive Body for Reduction of Booming Noise


View Details