Starting with hand sketches: This approach is also referred to as layout design. Design or engineering staff sketches the gearbox components, bearings, configuration, gear types, and provides sufficient information to initiate design review, analysis or prototype efforts. Layout design is an effective way to develop a sound "move-ahead" concept for any product.
Starting with CAD: Modern CAD (Computer Aided Design) software enables engineering and design staff to create 3D solid models of components and assemblies. The 3D models can then be imported into or digitally represented 2D digital file for detailing (applying design dimensional data). Advantages with starting with CAD modeling is that the components can be placed into a assembly file configuration for analysis and simulation. Additional benefits are interference checking, design review and manufacturing data is readily exported. Most modern CAD software allows for expedite changes to both the 3D model and associated engineering drawings. CAD software can also be used to create layout design information.
Starting with Analysis: This approach starts by identifying the gearbox configuration and then specifying the functional components like bearings, shafts, gear types and drive train elements then using analysis techniques for strength, function and lifetime cycle to the relevant specifications and standards to refine the gearbox components requirements.
For detail gear or gearbox design information see Gear Knowledge Menu.