During a trial on steam engine, it is found that the acceleration of the piston is 36 m/*^2 when the crank has moved 30° from the inner ****

Question

During a trial on steam engine, it is found that the acceleration of the piston is 36 m/s2 when the crank has moved 30° from the inner **** centre position. The net effective steam pressure on the piston is 0.5 N/mm2 and the frictional resistance is equivalent to a force of 600 N. The diameter of the piston is 300 mm and the mass of the reciprocating parts is 180 kg. If the length of the crank is 300 mm and the ratio of the connecting rod length to the crank length is 4.5,

find:

1. Reaction on the guide bars,

2. Thrust on the crank shaft bearings, and 3. Turning moment on the crank shaft.

Answer 1

Given : ap = 36/s2; θ = 30°; p = 0.5 N/mm2 ; RF = 600 N; D = 300 mm; mR = 180 kg; r = 300 mm = 0.3 m; n = l/r = 4.5

1. Reaction on the guide bars,

First of all, let us find the piston effect (Fp). We know that load on the piston,

and inertia force due to reciprocating parts,

We know that reaction on the guide bars,

2. Thrust on the crank shaft bearing

We know that thrust on the crank shaft bearings,

3. Turning moment on the crank shaft

We know that turning moment on the crank shaft,