Combine the data from problems 13-7 and 13-9. Run the linkage at a constant 2000 rpm. Calculate the inertia force and inertia torque at rot= 45°. Piston mass= 0.012.
Problem 13-7
A connecting rod of length l = 12 has a mass m3 = 0.020. Its mass moment of inertia is 0.620. Its CG is located at 0.4 I from the crankpin, point A.
a. Calculate an exact dynamic model using two lumped masses, one at the wrist pin, point B, and one at whatever other point is required. Define the lumped masses and their locations.
b. Calculate an approximate dynamic model using two lumped masses, one at the wrist pin, point E, and one at the crankpin, point A. Define the lumped masses and their locations.
c. Calculate the error in the mass moment of inertia of the approximate model as a percentage of the original mass moment of inertia.
Problem 13-9
A crank of length r = 3.5 has a mass m2 = 0.060. Its mass moment of inertia about its pivot is 0.300. Its CG is located at 0.30 r from the main pin, point O2. Calculate a statically equivalent two-lumped mass dynamic model with the lumps placed at the main pin and crankpin. What is the percent error in the model moment of inertia about the crank pivot.