Syllabus - Farm Machinery -II (AT502)

Tractor and tractor systems

Classification of tractors and IC engines. Review of thermodynamic principles of IC (CI & SI) engines and deviation from ideal cycle. General energy equation and heat balance sheet. Study of mechanical, thermal and volumetric efficiencies. Study of engine components their construction, operating principles and functions. Study of engine strokes and comparison of 2-stroke and 4-stroke engine cycles and CI and SI engines. Types of tractors – functional requirement and constructional details. Study of need for transmission system in a tractor. Transmission system – types, major functional systems. Study of clutch – need, types, functional requirements, construction and principle of operation. Familiarization with single plate, multi-plate, centrifugal and dual clutch systems. Study of Gear Box – Gearing theory, principle of operation, gear box types, functional requirements, and calculation for speed ratio. Study of differential system – need, functional components, construction, calculation for speed reduction. Study of need for a final drive. Study of Brake system – types, principle of operation, construction, calculation for braking torque. Study of steering system – requirements, steering geometry characteristics, functional components, calculation for turning radius. Familiarization with Ackerman steering. Steering systems in track type tractors. Study of Hydraulic system in a tractor – Principle of operation, types, main functional components, functional requirements. Familiarization with the Hydraulic system adjustments and ADDC. Study of tractor power outlets – PTO. PTO standards, types and functional requirements.

Traction and tractor-implement system

Traction terminology. Theoretical calculation of shear force and rolling resistance on traction device. Study of wheels and tyres – Solid tyres and pneumatic tyres, tyre construction and tyre specifications. Study of traction aids-ballasting the tractor. Tractor-implement hitching system, single point hitch, three point hitch system, different categories of three point hitch system, Study of tractor mechanics – forces acting on the tractor-implement combination. Determination of CG of a tractor and tractor-implement combination. Determination and importance of moment of inertia of a tractor. Study of tractor static equilibrium, tractor stability especially at turns. Determination of maximum drawbar pull. Familiarization with tractor as a spring-mass system.

Power tiller and other farm power sources

Power tiller as source of power, engine and transmission system in power tiller- types, construction, major functional requirement, hitching system in power tillers. Implements suitable for power tiller hitching.

Testing and safety with tractor and power sources

Introduction to tractor and power tiller testing. Deciphering the engine test codes.Ergonomical considerations and operational safety in operating the tractor controls.