Question

2. An engine has four cylinders arranged in two Vee banks, all being mounted symmetrically, above the main shaft. Each bank consists of two cylinders whose centre-lines are inclined at 90 to one another and whose connecting rods act on a single crankpin. The cranks of the two banks are set 180° apart a) Investigate the state of balance of the engine with respect to primary and secondary forces and couples and detemine the magnitude of any unbalanced forces or couples when the engine is running at 1500 rev/min. The reciprocating mass per cylinder is 5 kg, the crank radius 80 mm, the connecting rods 310 mm long and the banks are spaced 210 mm apart. b) Could the balance of the engine be improved by adding masses to the crankshaft? If so, find the magnitude and position of the balance masses to be added at 100 mm radius

Answer 1

Slage No. Date: symmeha call Given that, An engine has four cyllinders arranged in two vee banks all being above the mam shafft Each bonk consists of two cyllinders whose centre lines are inclined at go to one another - the engine is running at 1500 rpm mass of the Reciprocating - 5kg - the crank Rodius r= 80mm the connecting Red length _310mm banks are spoced = 210 mm The primary and secondry balance are F = my w?coso + cos207 w = QAN n = 2xã X 1500 The primary. Unbalanced force. myw?code " the secondry unbalanced force Es mrw?cosao calculators The primary unbalanced force mrw² ano - 8x8d (son) ca 180 Foop 98596 Answer

Page No. Date: 2 The secondry Unbalanced force + L110 the o o fs is moximum go, 180 and 360 = 8X Box (50x)² (aga xe Loop 31 F 8x 1578157 X 8 - 20831 Fs = 9544.41 N Answer (6) Not the balance of the engine be improved | by adding makce to the crankshaft because the dynamic balance of the masses in different manes in the Rotating plane. becouse in this problem we balanced the Reciprocating mass. there is no given Rotating masses are in the problem Hence, there is no balance mass of the enginge is adding masses to the crankshaft ...