For a 5 forward, 1 reverse speed constant mesh gear box:

a. Draw the layout.

b. Explain the working with advantages and disadvantages.

Advantages:-

• Helical or double helical gear teeth can be used for the gears instead of spur gears. Then gearing is quieter.
• Synchronizing devices can be used for smooth engagement.
• Any damage that results from faulty manipulation occurs to the dog clutch teeth and not to the teeth of the gear wheels.
• Once the dog clutches are engaged, there is no motion between their teeth. But when gear teeth are engaged, the power is transmitted through the sliding action of the teeth of one wheel on those of the other. The teeth have to be suitably shaped to transmit the motion properly.
• If the teeth on the wheel are damaged, the motion will be imperfect and noise will result.
• Damage is less likely to occur to the teeth of the dog clutches, since all the teeth engage at once, whereas in sliding a pair of gears into mesh the engagement is between two or three teeth.

Disadvantages:-

• Certain amount of skill is required by the driver to produce a quick and quiet gear change.