by Tracy Hagen
Casey Stoner has heaped praise for the transmission in his Honda RCV212 and has left the rest of the MotoGP paddock scratching their collective heads on what clever idea Honda has developed this time.
They can stop scratching and find out for themselves, thanks to Honda filing patent applications for the new gearbox in Japan and the United States (patent applications 2010-203478 and 20110023639, respectively).
The U.S. patent application, filed on February 3, 2011, does not reveal the assignee (i.e., Honda Motor Company), but the Japanese application reveals that Honda owns the patent and the inventors are Shinya Matsumoto and Jun Miyazaki.
The illustrations in the patent filings clearly show a dry clutch system. In the Japanese patent application the first drawing shows a partial side-view of a V-type engine. This leaves little doubt the invention is intended for MotoGP.
Honda’s 27,000 word patent application goes into great detail on the structure and operation of the multi-stage transmission. From a high-level Honda has arranged the gears sequentially. Instead of using the traditional yoke gear change system, Honda has a mechanism that slides along the driven-shaft to engage and disengage gear pairs.
Further evidence that the intended use of the invention is found in this phrase from the U.S. patent application: “According to an embodiment of the present invention, a multistage transmission is provided that prevents a wrong operation by regulating continuous operation for a shift at an extremely short time interval for avoiding a situation wherein a shift position of a shift drum and the actual speed are not matched (emphasis added).”
Honda filed the Japanese patent in February, 2009. There will be plenty of MotoGP engineers studying these two patents over the coming months.