(50 pts.): In the system shown below, shaft ( A C ) is to rotate at ( n=600 mathrm{rpm} ) and transmit torque ( oldsymbol{T}=mathbf{2 0 0 0} mathbf{~ l b} ).in to the machine at full load operation. The gears used in the system are spur gears having pressure angle ( 20^{circ} ), number of teeth of gear ( D ) is ( mathbf{4 0} ) teeth, and of gear ( B ) is ( mathbf{2 0} ) teeth. Assuming no power losses, then: (a) Determine the minimum diameter of shaft ( A C ), knowing that shaft ( A C ) is to be made of hot rolled steed having yield strength ( =mathbf{4 8} mathbf{k p s i} ), ultimate strength ( =75 mathrm{kpsi} ), fully corrected endurance limit ( S e=26 mathrm{kpsi} ), and the estimated fatigue stress concentration factors at shoulders in bending and torsion are respectively ( oldsymbol{K}_{oldsymbol{f}}=mathbf{2 . 1} ) and ( oldsymbol{K}_{f s}=mathbf{1 . 9} ). Use DE-Soderberg method with fatigue factor of safety ( oldsymbol{n}_{f}=1.5 ) (b) Determine the rotational speed of the driving sprocket ( Q ) in units of rpm, knowing that the speed ratio of the sprockets is to be ( oldsymbol{n}_{Q} / oldsymbol{n}_{oldsymbol{F}}=mathbf{2} ). Note that ( Q ) is the smaller sprocket as shown in the figure.. (c) Select an appropriate double strand sprocket-chain drive to be used as shown in this system. You need to identify (1) chain number, (2) number of teeth on driving sprocket, (3) number of teeth on driven sprocket, (4)

(50 pts.): In the system shown below, shaft AC is to rotate at n=600rpm and transmit torque T=2000lb.in to the machine at full load operation. The gears used in the system are spur gears having pressure angle 20, number of teeth of gear D is 40 teeth, and of gear B is 20 teeth. Assuming no power losses, then: (a) Determine the minimum diameter of shaft AC, knowing that shaft AC is to be made of hot rolled steed having yield strength =48kpsi, ultimate strength =75kpsi, fully corrected endurance limit Se=26kpsi, and the estimated fatigue stress concentration factors at shoulders in bending and torsion are respectively Kf=2.1 and Kfs=1.9. Use DE-Soderberg method with fatigue factor of safety nf=1.5 (b) Determine the rotational speed of the driving sprocket Q in units of rpm, knowing that the speed ratio of the sprockets is to be nQF=2. Note that Q is the smaller sprocket as shown in the figure.. (c) Select an appropriate double strand sprocket-chain drive to be used as shown in this system. You need to identify (1) chain number, (2) number of teeth on driving sprocket, (3) number of teeth on driven+sprocket, (4)