TYPES OF MANUAL GEARBOX

Types of Manual Gearbox:

Manual Transmission Gearbox:

In this type of transmission different speed ratio or gear ratio is selected by the driver manually. Some special skill of driving is required to operate this
type of gear box. According to their design, this is subdivided into three types.

(A.) Sliding mesh gear box:

When we talk about types of gearbox, this is one of the oldest type. It this, gears on the main shaft are moved right or left for meshing them with appropriate gears on the counter shaft for obtaining different speed. This type of gear box derives its name from the fact that the gears are meshed by sliding. One disadvantage of it is that, special skill is required to operate this gear box.

(B.) Constant mesh gear box:

This is one of the famous type used in twenty century. It this gearbox, all the gears are in constant mesh with each other all the time. The gears on the main shaft rotates freely without rotating the main shaft. Constant mesh gear box consists two dog clutches. These clutches are provided on the main shaft, one between the clutch gear and the second gear and the other between the first gear and reverse gear. When the left side dog clutch is made to slide left by means of gearshift lever, it meshes with the clutch gear and the vehicle runs on top speed. If this clutch slide right and mesh with second gear, than the vehicle runs on second gear speed. So in constant mesh gear box we can change the gear ratio by shifting the dog clutch. This type of gear box is more popular than sliding mesh because it creates low noise and less wear of gears.

(C.) Synchromesh gear box:

One big problem occur in constant mesh gear box is that when the driver engage the dog clutch, the main shaft and gear to be meshed running at different speed. So when engage this gear cause wear and tear of dog clutch. This problem is solved by a synchromesh gear box. This gear box is same as the constant mesh gear box except dog clutch is replaced by synchromesh devices.

Synchromesh gear devices works on the principle that two gears to be engaged are first brought into frictional contact which equalizes their speed after which they are engaged readily and smoothly. The synchromesh looks like as the cone clutch where the outer surface of cone consist the frictional surface. This type of gear box is widely used in automobile.