For a course titled Mechanical Design Optimization I produced a quantitatively-optimized gear train with ASME standard drawings, complete with geometric dimensioning and tolerancing. The project featured a 3-stage planetary gear train, designed to be used as a transmission for a wind turbine. From selecting sufficient off-the-shelf parts, to designing custom gears, carriers, and housing components, the project was a 2 month long exercise in design for requirements based on a real-world application.
The Gear Train
Below is a view of the overall 3-stage planetary gear train I created for the project:
The design process included a stepwise assembly instruction, from mounting gears and planet carriers to inserting seals and bearings in a way that promoted simple assembly. For example, the center ring gear was separated in half to allow it to be first mounted in each half of the housing before the rest of the gear train is installed.
GD & T
Much of the time spent on the project was directed at sufficient geomtric design and tolerancing. The decisions made in this stage must be optimized to meet design criteria while minimizing fabrication costs. Some examples of the parts that went through this process are the planet carrier and the outer housing: