Sliding Mesh Gearbox Construction, Working, Types

Table of Contents

WHAT IS A GEARBOX?

The gearbox is a mechanical device used to increase the output torque or to change the speed (RPM) of a motor. The shaft of the motor is connected to one end of the gearbox and through the internal configuration of gears of a gearbox, provides a given output torque and speed determined by the gear ratio.

THE NECESSITY OF GEARBOX

To maintain engine speed on all conditions of load and vehicle speed, the gearbox uses a system to maintain engine speed, while sacrificing the same road speed. To enable the engine to run faster on-road wheels as well as to multiply the torque, a gearbox is required.

Components of a Sliding Mesh Gearbox

1. Main axis-

It is the shaft used as the output shaft in a sliding link on which gear sets with internally splined grooves are neatly arranged. The outer surface of this shaft is splined so the gears can easily slide on this shaft to mesh with the appropriate gear.

2. Clutch shaft

It is the shaft that is used to bring the output from the engine to the gearbox with the help of the clutch and disengagement which is mounted on the end of the engine, the gear or a pair of gears are mounted on this shaft which is used for transmitting the rotary movement to the placement axis.

3. Lay Shaft

It is the shaft with gears mounted on its outer surface and is in continuous rotation with the clutch shaft as a gear on this shaft is always in contact with a gear on the clutch shaft, it is used as an intermediate shaft (between the main shaft and shaft gears) which engages the main shaft gears to impart proper output to the final drive.

4. Gears –

Two types of gears were typically used in the sliding link gearbox.

Spur Gear – This is the type of gear with spur gears on its surface, spur gears demonstrating maximum gearing area.

Helical Gear – This is the type of gear where the teeth are cut at an angle, unlike spur gears, this type of gear is smooth and less noisy.

Sliding Link Gearbox Operation

Gear shifting is achieved by meshing the main shaft gears with the countershaft gears, sliding the main shaft gears to the right or left to get proper gears, making you understand the operation of the 3-speed 1-reverse transmission used in the first automotive vehicles.

Bottom gear

The first gear provides the maximum low-speed torque that occurs when the smaller gear on the countershaft meshes with the larger gear on the main shaft to provide high torque.

second gear

The second gear provides less torque and higher speed than the first and is achieved when the main shaft medium-sized gear meshes with the smaller second gear on the countershaft and high speed and the second high torque are transmitted to the final drive.

Third gear

The third gear provides maximum speed and minimum torque for the final drive and is also known as high-speed gear or top gear in slip link gearbox, this gear is achieved when the smaller main shaft gear meshes with the shaft gear main. Larger countershaft gear. . Or we can say that the transmission has reached a maximum clutch shaft speed.

Reverse gear

When reverse is selected, the output shaft rotation is reversed, which is made possible by the use of an intermediate gear between the main shaft and countershaft, which changes the output shaft rotation and the vehicle begins to move in the direction reverse.