Crank-connecting rod mechanism for engine of miniature cross-country motorcycle

Abstract

The invention discloses a crank-connecting rod mechanism for an engine of a miniature cross-country motorcycle. The crank-connecting rod mechanism comprises a left crank, a right crank, a crank pin and a connecting rod, wherein the big head end of the connecting rod is positioned between the left crank and the right crank; the big head end of the connecting rod, the left crank and the right crank are connected with each other through the crank pin; the axial lines of the left crank and the right crank are in the same line and are parallel to the axial line of the crank pin; the distance between the axial lines of the left crank and the right crank and the axial line of the crank pin is 28.5 to 30.5 mm; the diameter of the shaft part of the right crank is 95 to 97 mm; the axial length of the right crank is 64 to 66 mm; and the distance between the centre of an installing hole at the big head end of the connecting rod and the centre of the installing hole at the small head end of the connecting rod is 94.3 to 96.3 mm. By changing a plurality of key parameters of the crank-connecting rod mechanism, the crank-connecting rod mechanism for the engine of the miniature cross-country motorcycle meets the functional requirements on high raising speed, strong explosive power, high torque, high crank rotating speed of the engine of the miniature cross-country motorcycle, and has the characteristics of ingenious conception, simple structure, easy implementation and the like.

Description

technical field [0001] The invention relates to a motorcycle engine, in particular to a crank connecting rod mechanism of a small off-road motorcycle engine. Background technique [0002] The crank-connecting rod mechanism is a key part of an internal combustion engine. Several parameters of its design, such as crank eccentricity, connecting rod center distance, crank diameter, etc., directly affect the compression ratio and output characteristics of the engine, and become the key factors that determine the power of the engine. key factor. In traditional motorcycle engines, the distance between the axis of the left and right cranks and the axis of the crank pin is about 24.75mm, the handle diameter of the right crank is about 90mm, and the shaft length of the right crank is about 84mm; the big end of the connecting rod is installed The center distance between the hole and the mounting hole of the small end is about 94mm. Since the traditional motorcycle engine is mainly us...

AI Technical Summary

Problems solved by technology

As a competition off-road vehicle engine, it is required that the engine speed up quickly, with strong explosive power, high torque, and high crankshaft speed, so the traditional motorcycle engine cannot meet the functional requirements of small off-road vehicles.

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