Multi stage radial tandem harmonic gear box

grabcad

Please take a look at the included Report and video for a more exaustive explanation of this entry.In summary:This is a modified 2 stage harmonic transmission, there are no roller bearings, the friction reduction is obtained by coating all the mating sliding surfaces with antifriction paint that allows no classic lubrication and no maintenance.The gear box has been designed to minimize the number of components by assigning more than one function to each of them, the final assembly includes only seven parts.First stage has a 1:28 reduction, secont stage 1:27. Combined reduction 1:756. Each stage has an estimated efficiency between 80% and 90%. Combined efficiency between 64% and 81%.Output torque is between 20320 mNm and 25700 mNm @ 1 rpm.It does not require exotic manufacturing tecniques and the final assembly is absolutely straightforward, everything happening along the z axis.Please take a look at the included PDF design report for more details, all components drawings are included.P.S.Please note that in the video showing the animation of the gearbox there is a glitch that show the first flexishaft rotating (a line along the periphery moving in a circle at high speed), this represent the travelling wave and not the actual rotation of the flexishaft, first stage flexishaft does not rotate, the wave generator here basically produce a standing wave.Similarly the second flexishaft show the same line representing the same thing, that is, the travelling wave generated by the second wave generator. In this case the flexishaft rotate and the rotation can be appreciated by looking at the golden colored teeth on top; it rotates pretty slow as it should be.These are glitches from the CAD that I could not turn off. It turns out that those glitches represent something interesting so I guess it's a lucky glitch :) .