Answer to Question #260644 in Mechanical Engineering for Nilesh

Question

. A machine press is worked by an electric motor, delivering 2.25 kW continuously. At the

commencement of an operation, a flywheel of moment of inertia 50 kg m 2 on the machine is

rotating at 250 rpm. The pressing operation requires 4.75 kJ of energy and occupies 0.75 second.

Find the maximum number of pressing that can be made in 1 hour and the reduction in speed of the

flywheel after each pressing. Neglect friction losses.

Answer 1

A separate turning moment diagram for a compound steam engine having three cylinders and the resultant turning moment diagram is shown in Figure given below.The resultant turning moment diagram is the sum of the turning moment diagrams for the three cylinders. It may be noted that the first cylinder is the high pressure cylinder, second cylinder is the intermediate cylinder and the third cylinder is the low pressure cylinder. The cranks, in case of three cylinders, are usually placed at 120° to each other.