Locomotives, (GATE & ESE) , Theory Of Machines, Mechanical Engineering

Variation in tractive forces

The resultant unbalanced force parallel or along the line of stroke in two cylinder locomotive after partial balancing is known as tractive forces.

In old days locomotives were not so much advanced because of this locopilot have to withstand  these high intensity shockes due to which they start vomiting .

Variation in swaying couple

It make the leading wheel to sway side to  side , produced due to unbalanced primary force produced along the line of stroke.

Hammer blow

The maximum value of unbalanced force perpendicular to line of stroke is known as hammer blow. Balancing mass cannot be attached reverse to the crank as it will hit the connecting rod i.e. why they are put up on wheels.

You can also refer mentioned vedio to understand hammer blow https://youtu.be/Q9-m_jjnSKU

Use of coupling rod in locomotives

Coupling rod was introduced in locomotives to decrease the amount of hammer blow by distributing balancing mass on driving as well as trailing wheels , so as to balance the reciprocating masses . This will increase the speed of locomotives . This was the development from passenger locomotive to express locomotive in which two-two wheels were coupled to the superfast locomotives in which three three wheels were coupled.