New generation shifting solution from Oerlikon Graziano provides fuel savings and easier gear shifting on heavy trucks

Rivoli (Torino) – Italy, June 29, 2012 – Oerlikon Graziano has developed a family of state-of-the-art synchronizers for heavy duty truck transmissions that sets new standards for fuel efficiency and ease of shifting. The first application of the technology, on new 9-speed and 14-speed premium gearboxes, has contributed to transmission efficiency improvement, helping to fuel saving and emission reduction. Already a leading supplier to the agricultural and construction industries, Oerlikon Graziano expects the high-efficiency synchronizers to generate significant new business in the heavy truck market.

The new synchronizers save fuel in two ways: by optimizing the shift to minimize torque interruption and by reducing steady-state drag torque in the transmission. They combine the high durability and high performance of Oerlikon Graziano’s existing Long Life synchronizers with a new internal activation system, the use of optimized clearances and lubricant paths for higher efficiency.

“Most new transmissions carry over existing synchronizer designs which limits the scope for efficiency improvements,” said Andrea Serra, product manager, synchroniser and powershift design, Oerlikon Graziano. “Our new synchronizer technology offers a step-change improvement in fuel efficiency for the next generation of heavy duty transmissions.”

The new synchronizers are configured in single and double cone arrangements, each with the same external geometry to allow great flexibility in transmission design. In all, four different synchronizer specifications are used on the 14-speed transmission and three on the 9-speed.The synchronizers have exceptionally high torque capacity - up to 18000Nm in the first applications – and use molybdenum coated steel cones for high durability with optimum friction. Future developments include the potential for carbon coating.  A key feature of the new technology is the integrated activation system which provides outstanding durability and ease of assembly.

By increasing the speed of a manual shift, Oerlikon Graziano has been able to reduce the torque interruption, keeping the engine at optimum efficiency for longer and reducing engine transients to save fuel.

Whichever gear is selected, large differences in rotating speed can exist across the other synchronizers. With a conventional design this leads to significant drag losses which impair efficiency, but the new synchronizers greatly reduce this effect to further improve fuel economy.

The new synchronizers improve the shift process during three distinct phases. Prior to synchronization, the integrated activation system provides optimized load characteristics to give improved consistency and outstanding durability, compared to a standard design.

The second phase, synchronization, has been shortened by the use of multi-cone technology, best-in-class friction materials and the optimization of geometries and tribological properties.

The third phase, from synchronization to engagement, has been improved by incorporating new internal features allowing smoother travel of the sliding sleeve, avoiding blocking problems and providing a more friendly engagement feel to the driver, and finally making this solution even more attractive in applications which are usually manual shift with air assistance, so any shift problems can immediately become obvious to the driver.  The new system ensures a fast, smooth and reliable shift under all conditions, making it an attractive alternative to a powershift system as it packages into a much smaller space.

“Our priority is to develop transmission technologies that allow our customers to introduce more capable and competitive vehicles, whether for cars, trucks or off-road applications,” said Serra. “The new synchronizers will support the next generation of truck transmissions with reduced fuel consumption and improved driver convenience.”

Note to editors: synchronizer operation

During a gearshift, synchronizers manage the speed difference between the previous gear selected and the next one, to ensure a smooth, quiet shift. In a typical transmission, all the gears are in constant mesh but only one pair is driving because in each pair, one of the gears freewheels until connected to its shaft by a synchronizer.

The hub of the synchronizer is splined to the shaft and carries three equi-spaced struts around its perimeter, on which the selector sleeve rides. In order to connect the synchronizer hub to the gear and engage the chosen ratio, the sleeve is moved towards the selected gear when the driver operates the gearshift lever.

Fine internal teeth on the synchronizer sleeve connect with opposing external teeth on the side of the gear to transmit power. But the sleeve cannot simply engage with the gear because they are rotating at different speeds. To prevent grinding or crashing of the synchronizer teeth, two further elements are carried between the hub and the gear: a synchronizer ring and one or more cone clutches.

The synchronizer, or blocker, ring carries fine external teeth matching those of the sleeve and the gear. It blocks the sleeve from travelling into full engagement until the speeds have been synchronized. The cones provide the necessary friction to adjust the rotating speed of the gear until it matches that of the shaft. At this point, the friction on the synchronizer ring decays and the ring’s external teeth line up with the sliding sleeve, allowing it to complete its travel and fully engage the teeth of the selected gear.

For further information, please contact:

Christopher Foster (European press contact)
Market Engineering
T +44 1295 277050
M +44 7775 449 655
christopher.foster@m-eng.com

Stella Roagna
Head of Communications & Marketing
Oerlikon DriveSystems
T +39 011 9570 206
F +39 011 959 1259
stella.roagna@oerlikon.com
www.oerlikon.com/graziano

 Andrea Serra
Product Manager, Shifting Solutions
Oerlikon Graziano
T+39 011 9570 499
F +39 011 9588179

About Oerlikon
Oerlikon (SIX: OERL) is a leading high-tech industrial group specializing in machine and plant engineering. The Company is a provider of innovative industrial solutions and cutting-edge technologies for textile manufacturing, drive, vacuum, thin film, coating, and advanced nanotechnology. A Swiss company with a tradition going back over 100 years, Oerlikon is a global player with more than 17 000 employees at over 150 locations in 38 countries and sales of CHF 4.2 billion in 2011. The Company invested in 2011 CHF 213 million in R&D, with over 1 200 specialists working on future products and services. In most areas, the operative businesses rank either first or second in their respective global markets 

 About Oerlikon Graziano
Oerlikon Graziano is a global player in power transmission field with more than 80 years of experience. Today the company is focused on the major markets as Off-Highway (Agricultural and Construction), Automotive and Industrial Application. Through its global footprint - in America (USA), Asia (China and India) and Europe (Italy, Russia and UK) – and its innovation, experience and high-tech solutions, Oerlikon Graziano is able to meet the customer needs, providing complete driveline systems as well as single gearing components.