Shifting Transmission

[sanddrag]

Bill Gold just posted a video of mesh shifting with 24 pitch gears, and I believe that is what team 60 has used for the past several years. The one thing I see with a mesh shifting system, is that while it is simpler to design and build, it requires more gears and more "stages" in the gearbox. First, you have the motor stage, let's say it is the Chiaphua. Then you have the reduction stage with a big gear that mates with the motor gear and with a long small gear also. Then you have the sliding stage with two gears, the bigger one one mating with the long small gear in the previous stages. Then you have the final/output stage which mates with the sliding stage, depending on which direction it is slid in. So, I'm counting 4 stages and 7 gears. In a constant mesh dog style transmission, Like Matt's or Andy's from 2003, you have only 3 stages and five gears (with only the Chiaphua) because the second stage doesn't have to slide along a previous stage, it stays put and the dog does the gear selection.

[Travis Covington]

That is not neccesarily true. One big reason they have so many gears is because they eliminate any sort of chain reduction entirely and drive the center wheels from the output shaft of the last gear stage. I think that a meshing system could have the potential to have less gears if done in a slightly different manner than they do it. Either way, they obviously have an elegant solution and it seems to be working great for them.

I will still put my vote in for the dog style transmissions. Of course



Also, Dave, drop me a line sometime. We are creating a service learning class next quarter with the ME department so we can get credit for helping out the high school FIRST teams. You might be interested.