Balancing fuel efficiency and performance is a key trend for vehicle designers worldwide. In pursuit of this goal a new generation of 4, 3 and 2 cylinder engines is entering the market. Variable speed transmissions are also growing in popularity and the addition of 5th and 6th gears in manual boxes is increasingly common in order to maximize fuel economy without impacting power output.
These innovations bring their own unique set of NVH issues, primarily they mean that gears are running with little or no load for longer periods of time, creating a high frequency whining noise that is more audible than ever. TrelleborgVibracoustic has created an innovative gearbox mounting solution that not only eliminates gearbox whine but also provides weight and cost savings and improves system durability.
The key to this new product lies in smart design. Traditional solutions to the problem centre on mass damper technology. The gearbox would normally be mounted on conventional rubber mounts and a large mass damper would be added to counter the high frequency vibration. TrelleborgVibracoustic has combined its considerable expertise in both power-train mounting solutions and mass damper technologies to produce a gearbox mount with an integrated mass absorber, eliminating the need for the secondary damper and creating significant weight and cost savings. What’s more the mount can be easily tuned to tailor it to specific frequencies making it suitable for multiple applications.
“The essential feature of the product is the rubber lobes that sit on either side of the main spring. Using advanced design tools we are able to tune the thickness and height of these lobes to target multiple frequencies” says Enrico Kruse, Director of Product Innovation. “Gearbox whine is a growing phenomenon, and our customers are increasingly asking for innovative, cost efficient solutions. This new mounting design can be tuned to combat specific frequencies and at the same time eliminates the need for additional components.”
“The mount was initially designed for a premium segment vehicle” adds Kruse, “but gearbox whine is a problem that is universally evident, across all vehicle classes, and this technology is instantly adaptable to suit most gearbox applications.”