Two-stage automatic shift engine

Abstract

The invention relates to a two-stage automatic shift engine for a light motor bicycle or an electric bicycle. The two-stage automatic shift engine is characterized in that a right crank arranged at one side of a crank shaft is provided with a low-speed clutch and a high-speed clutch which are respectively connected with a low-speed transmission gear and a high-speed transmission gear; a high-speed clutch friction disc is fixedly connected with a low-speed clutch friction disc back to back; a starting shaft is provided with at least three lines of spiral guide grooves; and a two-way ratchet wheel is arranged in a spiral guide groove positioned between a final gear and a starting chainwheel. The invention has compact structure, low manufacture cost and simple operation and respectively transmits power by two pairs of high-speed gear pairs and low-speed gear pairs in a high-speed state and a low-speed state, thereby realizing an automatic shift function of the power transmission of the engine by different clutches through the change of rotation speed; the two-way ratchet wheel is used for the stating shaft, and the engine can be started only by reversely stepping pedals of the staring shaft, thereby the operation is convenient and fast; and manpower driving can be realized by directly stepping the pedals under the condition of insufficient fuel.

Description

technical field [0001] The invention relates to an engine, in particular to a two-stage automatic gear-shifting engine of a light motorcycle or a power-assisted vehicle. The engine has the functions of manpower drive, kick start and electric start. Background technique [0002] Most of the used motors of existing mopeds or mopeds adopt a single-clutch structure without gear shifting. Although this structure is simple, there is no gear change when driving, and the engine speed is too high and the engine overheats. At present, there are also light motorcycles or mopeds that can change gears on the market. If you want to change gears while driving, you must first decelerate the engine, then pull the clutch handle to separate the clutch, and then step on the shift lever to switch gears. The gear shift fork makes the different gear pairs on the main shaft and the auxiliary shaft mesh to realize gear shifting. When shifting gears, both hands and feet are required, and the operatio...

AI Technical Summary

Problems solved by technology

[0002] Most of the engines used in existing light motorcycles or mopeds use a single-clutch structure without gear shifting. Although this structure is simple, there is no gear change when driving, and the engine speed is too high and the engine overheats.

At present, there are also light motorcycles or mopeds that can change gears on the market. If you want to change gears while driving, you must first decelerate the engine, then pull the clutch handle to separate the clutch, and then step on the shift lever to switch gears. The gear shift fork makes the different gear pairs on the main shaft and the auxiliary shaft mesh to realize gear shifting. When shifting gears, both hands and feet are required, and the operation is cumbersome. In addition, the structure of the shifting clutch device of this light motorcycle or moped is complicated, and the volume of the engine is large. The rigidity of the moving parts is poor and the manufacturing cost is high

In addition, the existing light motorcycle or moped engine usually adopts the pedal recoil starting method. This starting method is to realize the separation and engagement between the starting shaft and the starting gear through the recoil starting ratchet and the recoil starting ratchet spring. The structure of this kind of starting mechanism is relatively complicated. When starting, the clutch must be in the neutral position, which is inconvenient to operate; and the starting ratchet spring is easy to fall off or the resistance fails during use, so that the starting shaft and the starting gear cannot be reliably separated, thus affecting The reliability and service life of the starting mechanism, and the starting shaft and the starting gear will emit noise during the separation process

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