Engine having a counterweight device disposed on a crankshaft

摘要

An engine having a counterweight device disposed on a crankshaft is provided. The engine includes: a crankcase 2; a crankshaft 4 disposed rotatably in the crankcase 2; a start gear 5 sleeved on the crankshaft 4 and disposed outwardly of the crankcase 2; and a counterweight device 7. The crankcase 2 includes a first case half 21 and a second case half 22 that are interconnected to define a crank chamber 23. The crankshaft 4 includes a shaft portion 41 extending through the first and second case halves 21, 22, and at least one eccentric counterweight portion 42 extending radially and outwardly from the shaft portion 41 and disposed in the crank chamber 23. The counterweight device 7 is sleeved on the shaft portion 41 of the crankshaft 4, and is disposed outwardly of the crankcase 2 between the crank chamber 23 and the start gear 5.