4. INTRODUCTION
A gearbox is a collection of mechanical
components that deliver maximum power
from an engine by managing a series of gear
ratios that in turn operate a transmission.
5. Function Of A Gear Box
• Torque ratio between the engine and wheels
to be varied for rapid acceleration and for
climbing gradients.
• It provides means of reversal of vehicle
motion.
• Transmission can be disconnected from engine
by neutral position of gear box
6. Sliding Mesh Gear Box
• Normally 3 forward and 1 reverse gear ratios
• Spur gears are used
• Gear wheels on the main shaft engage with
gear wheels on the lay shaft (counter shaft) by
sliding themselves.
• Not used in automobiles now
7. POWER FLOW PATH IN GEAR
ENGAGEMENT
•When engine is running and the clutch is engaged, clutch shaft gear
drives the drive gear of the lay shaft and thus lay shaft also rotates.
•But the main shaft remains stationary as no gears in main shaft are
engaged with lay shaft gears.
11. •By operating gearshift lever, the larger gear of main
shaft is meshed with reverse idler gear.
•The reverse idler gear is always on the mesh with
counter shaft reverse gear. Interposing the idler gear.