Crankshaft mechanism for engine
AssigneeHonda Motor Co., Ltd.
InventorsHisashi Sakuyama, Shunsuke Muroi
Life of this patent
Estimating the term…
Abstract
A crankshaft mechanism for an engine wherein a crankshaft can be disposed close to the piston side while securing a moment of inertia. In the crankshaft mechanism for the engine including the piston, the crankshaft is provided with a crank pin and counterweight parts, and a connecting rod connecting the piston and the crank pin of the crankshaft to each other, the inner side of a circumferential end, on the opposite side of the crank pin, of each of the counterweight parts is cut out along a curve at equidistance R from the center Q of the crank pin, to obtain such a shape so as to avoid a projected part, projected in the direction of the piston, at the lower end of a small end part of the connecting rod when the piston reaches the bottom dead center.
Claims20
A crankshaft mechanism for an engine comprising:
- a piston;
- a crankshaft having a left part and a right part, each of the left and right parts being provided with a circular-shaped crank arm having a crescent-shaped counterweight part integrally formed on an inner surface thereof;
- a crank pin bridging between the circular-shaped crank arm of each of the left and right parts;
- and
- a connecting rod connecting said piston and the crank pin to each other with one of said counterweight parts being disposed on each side of the connecting rod;
- wherein each of the crescent-shaped counterweight parts is formed only on a portion of the inner surface of the crank arm opposite to where the crank pin is located, and an inner side of a circumferential end (44e) of each of the crescent-shaped counterweight parts is cut out along a curve at an equidistance (D1) from a center (Q) of said crank pin to obtain a shape on the inner side of the circumferential end of each of the crescent-shaped counterweight parts to avoid a projected part, projecting in a direction of a piston pin, from each side at a lower end of a small end part of said connecting rod when said piston reaches a bottom dead center.
A crankshaft mechanism for an engine comprising:
- a piston;
- a crankshaft having a first part and a second part, each of the first and second parts being provided with a circular-shaped crank arm having a crescent-shaped counterweight part integrally formed on an inner surface thereof;
- a crank pin bridging between the first and second parts of the crankshaft;
- a connecting rod connecting said piston and said crank pin to each other with one of the counterweight parts formed on each side of the connecting rod,
- wherein each of the crescent-shaped counterweight parts is formed only on a portion of the inner surface of the crank arm opposite to where the crank pin is located, each counterweight part including an inner side of a circumferential end (44e) that is cut out along a curve at an equidistance (D1) from a center (Q) of said crank pin;
- said cut out shape on the inner side of each of said counterweight parts avoids a projected part from each side at a lower end of a small end part of said connecting rod when said piston reaches a bottom dead center.
Dependencies are inferred from the claim text.