Patent ID: 6904884

Claim:
A balancer device for engines, in which first and second balancer shafts are arranged in parallel to a crankshaft and the crankshaft rotatingly drives first and second balancer weights at the same speed as that of the crankshaft, characterized in that the, first balancer weight is arranged on one end of the first balancer shaft in a direction along the crankshaft, the second balancer weight is arranged on the other end of the second balancer shaft in the direction along the crankshaft, and the first and second balancer shafts are made close to the crankshaft so that loci of rotation of the first and second balancer weights partially overlap a locus of rotation of that portion of the crankshaft, which is coupled to a conrod when viewed in the direction along the crankshaft, wherein both sides of that portion of the crankshaft, which is coupled to the conrod, are born through first and second journal bearings by side walls of a crank chamber, the first and second balancer weights are rotatable supported by the first and second balancer shafts, and balancer driven sears formed on the first and second balancer weights mesh with crank drive gears, which are arranged close to and outside the first and second journal bearings.