05-07-2013, 02:22 PM
Automatic transmission system
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INTRODUCTION
The modern automatic transmission isby far, the most complicatedmechanical component in today’sautomobile. Automatic transmissions containMechanical systems, Hydraulicsystems, Electrical systems andComputer controls, all workingtogether in perfect harmony whichgoes virtually unnoticed until there isa problem.
WHAT IS TRANSMISSION ?
• The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels
• Purpose of the transmission is to provide high torque at the time of starting the engine, hill climbing , accelerating and pulling a road.
PLANETARY GEAR SETS
A gear set in which all of the gearsare in one plane, grouped around eachother like the planets around the sun.The central gear is called the "sungear". In mesh with it is a circulargrouping of gears, called "planetgears", mounted on a rotating carrier.The planet gears also engage teeth onthe inner periphery of the "ring gear".By holding any one of the three gearelements motionless, different ratioscan be produced between the othertwo. Planetary gear sets are common inautomatic transmissions.
COMPUTER CONTROLS
The computer uses sensors on theengine and transmission to detect suchthings as throttle position, vehiclespeed, engine speed, engine load, brakepedal position, etc. to control exactshift points as well as how soft or firmthe shift should be. Once thecomputer receives this information, itthen sends signals to a solenoid packinside the transmission