System Description

STRUCTURE AND OPERATION

System Description


DESCRIPTION

With the use of 2 sets of planetary gears, A/T enables 4-speed transmission for forward and 1-speed transmission for backward, depending on the combination of 3 sets of multiple-disc clutches, a set of multiple-disc brakes, a set of one-way clutches and a set of brake bands.

CLUTCH/BRAKE AND BAND CHART

x: Operated





*: Operates during "progressive" acceleration.

P POSITION (PARKING MECHANISM)

When the selector lever is shifted to the "P" position, the parking pole engages with the parking gear (integrated with the idler gear), fixing the output shaft in place.

TRACTION TRANSMISSION OF EACH RANGE

"P" position, "N" position





The drive force from the input shaft is not transmitted because all clutches and bands are released.
"1" position, "D1", position





- The drive force from the input shaft is transmitted via the engaged low clutch and turns the rear sun gear forwards. This causes the rear internal gear to turn backwards, however it is stopped by the one-way clutch.
The rear gear turns forward and the force is transmitted to the output gear after being slowed down.
NOTE:
When coasting, because the front carrier is able to turn forward, engine braking does not occur.
- The status of each planetary gear is as shown below.
Front planetary gear





"1" position, "D1" position,engine brake





- The drive force from the input shaft is transmitted via the engaged low clutch and turns the rear sun gear forwards. This causes the rear internal gear to turn backwards, however it is stopped by the one-way clutch.
The rear carrier turns forward and the force is transmitted to the output gear after being slowed down.
- The status of each planetary gear is as shown below.
Front planetary gear





Rear planetary gear






"2" position, "D2" position





- In 1st gear, the front sun gear is turning in reverse. However the 2-4 brake operates and fixes the front sun gear in place. When this happens, the front carrier turns in the forward direction. As a result, when the front internal gear transmits force to the output gear, it turns forward at a faster speed than when in 1st gear.
- Because the rear internal gear and front carrier are turning forward, the one-way clutch turns freely.
- The status of each planetary gear is as shown below.
Front planetary gear






"D3" position





- The low clutch and high clutch that are connected to the input shaft are engaged, creating a single power transmitting mechanism and rotating while engaged.
- The status of each planetary gear is as shown below.
Front planetary gear






"D4" position





- The drive force input from the input shaft is transmitted by forward rotation of the engaged high clutch to the front carrier. Operation of the 2-4 brake fastens the front sun gear in place, causing the front carrier to turn forward. As a result, the front internal gear turns faster, the rear carrier turns forward, and force is transmitted to the output gear.
- The status of each planetary gear is as shown below.
Front planetary gear





"R" position





- The drive force from the input shaft is transmitted by forward rotation of the engaged reverse clutch to the front sun gear. Engagement of the low & reverse brake fastens the front carrier in place, causing the front internal gear to turn in reverse and transmitting force by reverse rotation to the output gear.
- The status of each planetary gear is as shown below.
Front planetary gear