Gearbox Design

The goal was to create a 4:1 speed reduction ratio gearbox that was to handle human scale exerted forces and not break easily. We chose a 90 degree angle transmission gear type pair, which was the straight bevel gear. The additional feature that my friend and I decided to add to this gearbox was the offset between the input and output shaft, which meant we needed to add another pair of gears that would enable the generation of offset between the input and output gears. For this a pair of helical gears were added to the design with a 2:1 speed reduction ratio. This meant that the bevel gears needed to be rescaled and adjusted the ratio between those to a 2:1 reduction ratio. This allowed for a final 4:1 speed reduction ratio gearbox with an offset. Then, I designed a casing for the gearbox. This gearbox was to be 3D printed so the casing, gears, shape of shafts (square shafts), and bushings for load support were designed and dimensioned in SolidWorks with meticulous care and attention for clearance fit and error-free 3D printing. As well, the casing and gears have slots and holes on them, to make them lighter and quicker to print, as shorter printing time was required by the university's makers' space. The gearbox CAD assembly was then converted to an STL file, sliced and submitted for 3D printing. The final 3D printed gearbox and corresponding assembly drawings can be seen below.