A swifter shifter for truck transmissions

  • 29-Aug-2012 04:14 EDT
Synchronizer diagram Hi-res.jpg

Oerlikon Graziano claims a number of improvements for its new heavy-duty truck tranmission synchronizer.

Transmission specialist Oerlikon Graziano of Italy has developed a new family of synchronizers for heavy-duty truck transmissions, designed to speed up gearshifting and deliver improved fuel consumption. This is the company’s first component for heavy truck transmissions, having gained experience in the agricultural and construction machinery sectors.

The first applications will be for nine- and 14-speed transmissions. The company claims that the new synchronizers will reduce fuel consumption and emissions in two ways—by minimizing the torque interruption and reducing the steady-state drag torque in the transmission.

Many European heavy-duty transmissions are now automated, but according to Andrea Serra, Product Manager, Synchronizer and Power Shift Design, Oerlikon Graziano, most of the heavy-duty truck transmissions under development in Europe, India, and China are manual transmissions. “We have developed these new synchronizers specifically for manual transmission gear change functions. There is also an automatic synchronizer for the high/low range change function.”

Although Oerlikon Graziano has signed supply deals to transmission manufacturers, no further details are available at the moment.

The synchronizers are set up in single- and double-cone arrangements, all sharing the same external geometry. Construction is from molybdenum coated steel cones offering torque capacities of up to 18,000 N·m (13,276 lb·ft). Oerlikon Graziano is also considering the use of carbon coating. The company says that the integrated activation system of the synchronizers is key to reducing the large differences in their relative rotating speeds. Four different synchronizer specifications are used on the 14-speed transmission and three on the nine-speed.

The company says that the synchronizers improve the shift over the three phases of a gearshift. Before synchronization, the integrated activation system is said to optimize the load characteristics, giving improved consistency and durability. The multicone technology is said to shorten the synchronization phase, while the sliding sleeve travel is said to be smoother, reducing balking.

Oerlikon Graziano is best known for its transmission synchronizers for agricultural machinery and also produces similar equipment for construction machinery. The company plans to expand further into the truck sector, following the launch of these new synchronizers.

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