Introduction
Need for Transmission system. Tractive Effort and Resistances to Motion of a vehicle. Requirements of
transmission system. Classification of Transmission systems. Single, Two or Four Wheel drive systems. Multi
axle drives. Chain, Shaft and Electric drives. Location of transmission system. Different transmissions in scooter,
car, MUVs and transport vehicles of Indian make.
Clutch
Principle of operation, Constructional details, torque capacity and design aspects. Different types of clutches.
Operation of single plate: helical spring and diaphragm type, and multiplate clutch. Centrifugal and Automatic
Clutch. Dry and Wet type of clutch. Friction lining materials. Over-running clutch. Modes of operating a clutch –
mechanical, hydraulic and electric.
Gear box
Determination of gear ratios for vehicles. Performance characteristics in different speeds. Different types of gear
boxes – sliding, constant and synchromesh type. Need for double declutching and working of synchronizing unit.
Power and economy modes in gearbox. Transfer box. Transaxles. Overdrives. Gear shifting mechanisms –
mechanical link and wire types
Hydrodynamic drive
Fluid coupling- principle of operation, constructional details. Torque capacity. Performance characteristics,
Reduction of drag torque. Torque converter-Principle of operation, constructional details, performance
characteristics, converter coupling, multistage torque converters and Polyphase torque converters.
Hydrostatic drive
Hydrostatic drive - Various types of hydrostatic systems - Principles of hydrostatic drive system, Advantage and
limitations, Comparison of hydrostatic drive with hydrodynamic drive - Construction and working of typical Janny
hydrostatic drive.
Electric drive
Electric drive Principle of early and modified Ward Leonard Control system. Advantage & limitations.
Performance characteristics. Study of drive system in an electric and hybrid vehicle.
Automatic transmission applications
Chevrolet "Turboglide" Transmission, Powerglide Transmission Toyota "ECT-i" Automatic Transmission with
Intelligent Electronic controls system, Hydraulic Actuation system.