How the Toyota Camry automatic transmission works
Concept:
Automatic transmissions (AT) allow the driver to change gears without using the clutch. This is achieved through the use of hydraulic fluid that circulates through the gearbox and activates various mechanisms to change gears.
Components:
Main components of Toyota Camry automatic transmission:
* Torque Converter: Connected to the engine and transmission and transmits power.
* Planetary Gearbox: Contains gears that provide different gear ratios.
* Hydraulic Control: Consists of valves that control the flow of hydraulic fluid.
* Sensors: Monitor various conditions such as vehicle speed, gas pedal position and fluid temperature.
Working principle:
To understand how automatic transmission works, consider the following scenario:
1. Starting: When the driver starts the engine, the torque converter transfers power from the engine to the transmission. Pressurized fluid circulates through the transmission, activating the valves and pistons.
2. Shifting into first gear: When you press the gas pedal, fluid under pressure is directed to the first gear valve. This drives a piston that locks certain gears in the planetary gearbox, producing the smallest gear ratio.
3. Shifting: As the vehicle speed increases, the sensors transmit information to the hydraulic control system. The system regulates fluid flow to activate various valves and pistons to shift into higher gears.
4. Downshifting: When the vehicle speed decreases or when the brake pedal is pressed, the system reduces fluid pressure. This shifts the transmission into lower gears, providing the necessary engine braking.
5. Parking mode: When the driver places the vehicle in the parking position, the transmission is mechanically locked, preventing the vehicle from moving.
Operating modes:
Toyota Camry automatic transmission usually has the following operating modes:
* Drive (D): Normal driving mode that automatically changes gears based on driving conditions.
* Reverse (R): Shifts into reverse.
* Neutral (N): Disconnects the transmission from the engine, allowing the vehicle to coast.
* Park (P): Locks the gearbox when the car is stationary.
* Manual (M): Allows the driver to manually select gears, similar to a manual transmission.