Patent ID: 6227161
Filing Date: 2001-05-08
Classification: F01B,F02B,F02F

Abstract:
A piston-crank mechanism for converting reciprocating movement of a piston into rotational movement of a crankshaft, said piston-crank mechanism comprising:a piston portion reciprocating and sliding within a cylinder;a free-link, one end of said free-link being pivoted on said piston portion via a piston pin arranged in the vicinity of the axial line of said piston portion; andan intermediate link mechanism formed of a plurality of links for transferring reciprocating movement of said piston portion for conversion into rotational movement of the crankshaft, said intermediate link mechanism being connected to said free-link at a free-link pivoting point formed on the other end of said free-link while said intermediate link mechanism being swingably connected to a crank arm with a crank pin of the crank arm, the crank arm being rotatable with the crankshaft in unison,wherein said intermediate link mechanism comprises a connection rod, one end of the connection rod being swingably connected to the crank arm with the crank pin, and a cross-link swingably connected to the other end of the connection rod and to the free-link at the free-link pivoting point while the cross-link being pivoted on a crankcase, andwherein movement of the cross-link is restrained by swinging movement thereof about the pivoting point on the crankcase, so that in an intermediate position of reciprocating movement of the piston, the straight line connecting the top and bottom dead centers of the crank pin together meets approximately at a right angle with the straight line connecting the pivoting point of the cross-link on the crankcase to the pivoting point thereof on the connection rod.