BALANCER MECHANISM FOR 2-CYCLE INTERNAL-COMBUSTION ENGINE

摘要

PURPOSE:To make an engine smaller with a shorter distance between a crank shaft and a balancer shaft by arranging a balance weight of the balancer shaft to be rotated synchronizing the crank shaft so as to be displaced axially outward from a crank weight. CONSTITUTION:A balancer shaft 31 connected to a crank shaft 21 with gears 32 and 35 is mounted rotatably on cases 11 and 12 through bearings 15 and 16 with the length enough to have both ends thereof extending outside the cases 11 and 12 as specified. Thus, the balance weights 33 and 34 are respectively positioned outside the cases 11 and 12 displaced axially outward from the crank weights 22 and 22 and no consideration should be given to interference between walls 11a and 12a forming a crank chamber R and the balance weights 33 and 34 in the arrangement of the balancer shaft 31.