Describe the construction of gear drive of camshaft drive arrangement with sketch.
Gear Drive of Camshaft Drive:
Camshaft is driven by the crankshaft either by a pair of meshing gears (timing gears) or by means of a pair of timing sprocket connected by a chain. The cam shaft gear or sprocket has twice as many teeth as the gear or the sprocket on the crankshaft. This gives 1:2 gear ratio, the camshaft turns at half the speed of the crankshaft. Thus every two revolutions of the camshaft produce one revolution of the camshaft and one opening and closing of each valve in the four cylinder engine. The gear and sprocket maintain a definite time relationship between the camshaft and crankshaft to ensure opening the valves exactly at the correct time in relation to piston position.