Question

15. A four stroke oil engine developing 75 kW at 300 r.p.m is to have the total fluctuation of speed limited
to 5%. Two identical flywheels are to be designed. The workdone during the power stroke is found to
be 1.3 times the average workdone during the whole cycle. The turning moment diagram can be
approximated as a triangle during the power stroke. Assume that the hoop stress in the flywheel and
the bending stress in the arms should not exceed 25 MPa. The shear stress in the key and shaft
material should not exceed 40 MPa. Give a complete design of the flywheel. Assume four arms of
elliptical cross-section with the ratio of axes 1 : 2. Design should necessarily include (i) moment of
inertia of the flywheel, (ii) flywheel rim dimensions, (iii) arm dimensions, and (iv) flywheel boss and
key dimensions and sketch showing two views of the flywheel with all the dimensions

Answer 1

While doing the problem please take hoop stree around 6 MPa , i take here the maximum value 25 MPa please correct while doing.