Through this work, we aim to design a two stage speed reducer. Interest will be given to all components of this speed reducer, (shafts, gears, bearings and keys). Some important data are given to design properly the gearbox. Power to be delivered: 15 kW Input speed: 1800 rey/min > Output speed: 90 rey/min Type of gears: Helical Maximum gearbox size: 600 x 400 x 400 mm > Output shaft and input shaft in-line Gear and bearing life 15 000 hours; infinite shaft life A rough sketch of the desired gearbox is given. You are required to prepare a detail design report. In the following some guidelines to be taken into consideration when you design your gearbox. 1) Design each of the gears of your gear box a. Select the material of your gears b. Design for strength c. Design for Fatigue (endurance criterion) d. Design for wear 2) Design the shaft 2 of your gearbox a. Select the material of your shaft (E, S.) b. Design for strength (use Goodman criterion) c. Design for deflection (allowable deflections of spur gears can be considered) d. Design for critical speed. 3) Select the appropriate keys (type, and dimension) for power transmission. (Include the catalogs you based your design on into your report) 4) Draw the final gearbox with all dimensionned machine elements, showing the direction of rotational speed, direction of helix angles, selected keys, obstacles for bearings' rings. (You can use CAD software for your design) M 2 4 3 g