Torque converter
The torque converter is used to transfer rotation from the engine to the gearbox. It consists of:
* Pump wheel attached to the motor.
* Turbine wheel connected to the gearbox shaft.
* Stator located between the pump and turbine wheels.
When the engine rotates, the pump wheel creates a flow of transmission fluid. Fluid enters the turbine wheel, causing it to rotate. The stator directs the flow of fluid, increasing torque.
Planetary gear
A planetary gear is used to change the gear ratio. It consists of:
* Sun gear connected to the motor shaft.
* Planetary gears rotating around a central axis.
* Ring gear connected to the gearbox shaft.
Varying the rotation of the various inputs and outputs of the planetary gear allows different gear ratios to be created.
Drum brake
A drum brake is used to lock the sun gear, creating a direct drive. It consists of:
* A drum attached to the sun gear.
* Pads pressed against the drum to create friction.
Hydraulic control unit
The hydraulic control unit controls the flow of transmission fluid through the planetary gear and drum brake. It is controlled by an electronic control unit (ECU).
Electronic control unit (ECU)
The ECU receives input from sensors such as the gear selector position sensor, speed sensor, and transmission fluid temperature sensor. Based on this data, the ECU controls the hydraulic control unit to change the gear or lock up the torque converter.