You must design the components of the system. If information is not given you must make an assumption of the value or formula. Clearly STATE any assumption made and JUSTIFY your choice. When using a formula clearly state what each symbol represents in terms of the name and unit e.g. Power in Watt or W. REQUIREMENTS A shaft that is driven by a 50 kW AC electric motor with a star/delta starter by means of a belt(s). The motor speed is 1250 rpm. The shaft drives a fan by means of a spur gear train. The fan must rotate at 500 rpm in the SAME direction as the electric motor. The shaft is supported by 2 sliding bearings one at each end of the shaft. The system is used for 24 hours per day. The layout is as follows: Fan Spur gear Gear 1,5 m Belt Bearing Electric motor Design: 1. Belt drive Details of belt drive Number of belts Type of belt(s) Both pulley diameters Sketch of design ( 30 ) 2. Shaft Shaft diameter at bearing Nominal size of shaft chosen before machining Ignore shaft bending Sketch of design ( 10 ) 3. Bearings Clearance and length of bearing Sketch of design 4. Gear Train Details of gears 5. Keys Material chosen Number of teeth of all gears Diameters of all gears Sketch of design Method of fixing gear and pulley to shaft Size of the key(s) Sketch of design Welding is not allowed. (10) ( 20 ) (10) GIVEN CRITERIA Shaft Mild steel Solid Ultimate shear stress Ignore deflection or bending 350 Mpa Bearings Oil SAE 10 Operating temperature 40 C Spur gears Pressure angle 20 Key Max shear stress 80 Mpa Belts Flat belt Thickness Coefficient of friction Density Permissible stress Wedge belt Use SPB type belts 0.8 3.0 mm 1100 kg/m 11 MN/m