CONSTANT MESH GEAR BOX

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Construction and working of a constant mesh gear box

Constant gear mesh gearbox employed helical gears for power transmission. The gears are rigidly fixed in the lay shaft. The gears in output shaft rotates freely without engaging with shaft, thus not transmitting power. The gears in both shafts are always meshed together.

To engage the gears with output shaft dog clutch is used. the dog clutch is shifted by the seletor fork moved by gear lever.To provide reverse gearing a idler gear is used. 
When the gear lever is pushed, the gear selector fork pushes the dog clutch. The dog clutch engages the gear and the output shaft, thus power from lay shaft now transmitted to output shaft.

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