Oil pump

1. Flywheel attachments
2. Casing connected to pump
3. Lock-up clutch
4. Turbine
5. Pump
6. Stator
7. Motion input shaft

OIL PUMP

The oil pump used for the AISIN automatic transmission is of the inner gear type. It is located between the torque converter and gearbox casing, and is driven directly by the converter pump impeller.

The functions of the oil pump are as follows:

• to provide the necessary pressure to the hydraulic control system and the gearbox control components (clutches and brakes);
• to send an oil flow into the torque convert-er case in order to cool it and to be able to operate the lock-up clutch;
• to lubricate the moving components of the gearbox;
• to circulate oil in the cooling system.

Structure of the oil pump

1. Inlet side
2. Delivery side

EPICYCLIC GEARS

The AISIN automatic transmission uses two epicyclic gear sets for obtaining the five trans-mission ratios (4 forward gears + reverse gear).

The rear gear set P1 is a simple epicyclic gear set comprising a sun gear S1, four planet gears ST1 and a crownwheel K1. The front gear set P2 consists of an epicyclic gear set comprising a sun gear S2, four inner planet gears ST2, four outer planet gears ST3 and a crownwheel K2. The shafts of the planet gears ST1, ST2 and ST3 are attached to the gear train carrier T1.

Epicyclic gear sets P1 and P2

• K1. Crownwheel of P1
• K2. Crownwheel of P2
• S1. Sun gear of P1
• S2. Sun gear of P2
• ST1. Planet gears of P1
• ST2. Inner planet gears of P2
• ST3. Outer planet gears of P2
• T1. Gear train carrier