At3 Planetary Gearset And Simpson 694j16

Planetary Gearset & Simpson

Planetary Gearset

Planetary Gearset • A simple planetary or epicyclic gearset can provide – overdrive, – reverse, – forward reduction, – neutral, and – direct drive ratios.

Planetary Gearset • 3 main Components – Sun gear with external gear teeth – Carrier

with planetary pinion gears mounted to it

– An internally toothed

ring gear or annulus

Planetary gear configuration

Maximum forward reduction

Maximum forward reduction • greatest torque, • lowest speed is produced with the sun gear as input, the ring gear stationary, and the carrier as the output.

Maximum Overdrive

Maximum overdrive • lowest torque, • greatest speed is produced with the carrier as input, the ring gear stationary, and the sun gear as output.

Minimum forward reduction

Minimum forward reduction • good torque • low speed is produced with the ring gear as input, the sun gear stationary, and the carrier as the output

Slow Overdrive

Slow overdrive • lower torque • greater speed is produced with the carrier as input, the sun gear stationary, and the ring gear as output.

Slow Reverse

Slow reverse • opposite output direction • greatest torque • lowest speed is produced with the sun gear as input, the planetary carrier stationary, and the ring gear as output.

Fast Reverse

Fast reverse • opposite output direction • greater torque • low speed is produced with the ring gear as input, the carrier stationary, and the sun gear as output.

Direct Drive

Direct Drive • Direct drive is produced if any two gearset are locked together.

Neutral Condition

Neutral Condition • With no held or stationary member, there can be no output. The result is a neutral condition.

Planetary Gearset • An automatic transmission does not require a conventional flywheel because the weight of the torque converter provides enough mass to dampen engine vibrations.

Planetary Gearset

Planetary Gearset

Planetary Gearset

Planetary Gearset

SIMPSON GEAR TRAIN • One of the most popular compound planetary design is the Simpson gear set. • Named for its inventor, Howard Woodworth Simpson (1892–1963), an American automotive engineer, the Simpson gear set consists of two simple planetary gear sets that share a common sun gear. • This combination is capable of providing three forward gears, as well as neutral and reverse.

Shift Modes

Shift Modes : P • The engine will only start if the selector is in either the park or neutral position. • In park, the drive shaft is locked so that the drive wheels cannot move.

Shift Modes : R • The reverse gear selector position is used to move the vehicle in reverse. • Reverse usually uses a lower gear ratio than any of the forward gears.

Shift Modes : N •

In the neutral position no torque is being transmitted through the automatic transmission/transaxle.

Shift Modes

: D

• For ordinary driving, the driver moves the selector to the ‘drive’ position. • The transmission starts out in the lowest gear and automatically shifts into higher gears as the car picks up speed.

Shift Modes

: 2

•

The second position is used for slowing the vehicle while descending long grades.

•

In this gear selection, the vehicle speed is controlled and the engine speed is increased to provide engine compression braking.

• This gear selection is used for the gentle grades at a moderate vehicle speed.

Shift Modes •

: L

The first (or low) position is used for slowing the vehicle while descending long grades.

• In this gear selection, the vehicle speed is controlled and the engine speed is increased to provide engine compression breaking. • This gear selection is used for the steepest grades at the lowest possible speed.

Clutch Application Chart

Schematic

Schematic

D 1

Schematic

D 1

Powerflow

D 1

Schematic

D 2

Schematic

D 2

Powerflow

D 2

Schematic

D 3

Schematic

D 3

Powerflow

D 3

Powerflow

D 3

Schematic

R

Powerflow

R