GEARBOXESBy: Chandan ManghnaniFunctions of GearboxProvide means to vary torque.Allow to change the speed.Provides a neutral position.A means to back the car by reversing the direction of rotation of the drive is also provided by the transmission.2Types of GearboxSliding mesh gearboxConstant mesh gearboxSynchromesh gearbox Epicyclic Gearbox3Sliding mesh type gearbox

Sliding mesh type gearboxThe power comes from the engine to the clutch shaft and then to the clutch gear which is always in mesh with a gear on the lay shaft.All the gears on the lay shaft are fixed to it and as such they are all the time rotating when the engine is running and clutch is engaged.

Gear positions in sliding mesh type Gearbox

Working of Sliding Mesh Type Gearbox

Disadvantages of Sliding Mesh type Gear BoxGear noise due to the type of gear. The difficulty of obtaining a smooth, quit and quick change of gear without the great skill and judgment.Cannot use helical gears in this type of gear box.Constant mesh gearboxAll the gear are in constant mesh with the corresponding gears on the layshaft. The gears on the splined main shaft are freeThe dog clutch are provided which are free to slide on the main shaft.The gears on the lay shaft are fixed.Constant mesh gearbox

Constant Mesh type Gearbox

Advantages of Constant Mesh Type GearboxAs the gear remain always in mesh, it is no longer necessary to use straight spur gear. Instead helical gear is used which are quieter running.Wear of dog teeth on engaging and disengaging is reduced because here all the teeth of the dog clutches are involved compared to only two or three teeth in the case of sliding gears.

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