auto transmission the slide

7/31/2019 Auto Transmission the Slide

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The modern automatic transmission is by far, the most complicated

mechanical component in today's automobile. An automatic gear box can automatically change the gear ratios as vehicle

moves.

This presentation will help you understand the concepts behind what goes oninside these technological marvels.

Presented by- Rohit sharma & Siddharth shroff


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History Modern automatic transmissions can trace their origins to an early Horseless

Carriage gearbox that was developed in 1904 by the Sturtevant Brothers.

Auto transmission was first introduced by General Motors cadillac &Oldsmobile in the year 1939.

The Hydramatic was the first fully automatic mass- produced transmissiondeveloped for passenger automobile use.



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Basic Types of Auto-trasmission

Rear Wheel Drive Car

Front Wheel Drive Car



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Modes of Automatic transmission

Park (P)- this selection prevents the transmission from rotating, and thereforethe vehicle from moving.

Reverse (R)-this engages reverse gear within the transmission, giving theability for the vehicle to drive backwards.

Neutral (N)-this disengages all gear trains within the transmission. Drive (D)-this position allows the transmission to engage the full range of

available forward gear trains.

Second (2 or S)-this mode limits the transmission to

the first two gear ratios.

First (1 or L)-This mode locks the transmissionin first gear only.



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Working of Auto-transmission Planetary Gear set which are the mechanical systems that provide the various

forward gear ratios as well as reverse.

The Hydraulic Systemwhich uses a special transmission fluid ,OilPump,Valve Bodyto control the Clutches.

TorqueConverter,Governor,Throttle cable are also

used in the Auto-transmission assembly.

Compound Planetary GearsetPresented by- Rohit sharma & Siddharth shroff


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Parts & Operation Pump- draws transmission fluid from a sump and pressurizes it.

Valve body-The valves controls which ratio is selected on the gearset.

Clutches - to effect gear changes, a type of device known as a sprag or rollerclutch is used for routine upshifts/downshifts.

Hydraulic & lubricating oil-provides lubrication, corrosion prevention, and ahydraulic medium to convey mechanical power .



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Planetary Gear SetDeceleration

Power input: ring gearPower output: planetary carrier

Direct Coupling

Power input: sun gear, ring gearPower output: planetary carrier

Reverse Rotation

Power input: sun gearPower output: ring gear



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Advantages of Auto-TransmissionIt also found used during World War II in some militaryvehicles.

It makes the drive very comfortable.

In India recently GM launched Chevrolet Cruze VCDi ,

6-speed automatic version .

It increases the ease of drive without the clutch padel & gear shifts.



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Conclusion As many people are preferring Automatic Transmission cars over the Manual

Transmission cars it can be predicted that this technology will gain a lot of

attention in near future. Automatic Transmission will create boom in the auto industries.



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References http://en.wikipedia.org/wiki/Automatic_transmission

http://www.familycar.com/transmission.htm

file:///R:/auto%20transmission/web%20pages/Automatic%20transmission%20-%20Automotive%20illustrated%20glossary.htm

file:///R:/auto%20transmission/web%20pages/HowStuffWorks%20%20Compound%20Planetary%20Gearset%20.htm

file:///R:/auto%20transmission/web%20pages/How%20Automatic%20Transmission%20Works%20.htm

Automobile Engineering book- DM Gokhle.



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