Automatic transmission (AT) forklift
A forklift’s automatic transmission is a mechanism that allows you to vary the transmission ratio between the engine and the drive wheels, providing smooth gear changes for improved performance and maneuverability.
Main components of automatic transmission:
* Torque Converter: A device that transfers power from the engine to the transmission through the use of fluid.
*Planetary Gearbox: A set of gears that transmit power to various ratios.
* Brake Bands and Disc Brakes: Used to engage and disengage gears.
*Control valves: Regulate the flow of fluid in the transmission to change gears.
* Control unit: An electronic or hydraulic component that controls the operation of the automatic transmission.
Operating principle of automatic transmission:
1. Torque Converter: When the engine starts, the fluid in the torque converter moves, transferring power from the engine to the transmission.
2. Planetary gearbox: Fluid circulates through the planetary gearbox, which includes the planetary gears, sun gears and carrier.
3. Brake bands and disc brakes: When commanded by the control unit, the brake bands or disc brakes are turned on or off, locking or releasing the planetary and sun gears.
4. Gear Shift: When the control unit detects a change in load or speed, it sends a signal to the solenoids, which activate the brake bands or disc brakes, distributing fluid and changing the gear ratio.
5. Reverse: For reverse, separate brake bands or disc brakes are used to lock the reverse gear, directing fluid to reverse the direction of rotation.
Automatic transmission modes:
Automatic transmissions of forklifts usually have several operating modes:
* Drive (D): For normal forward driving.
* Reverse (R): To move backwards.
* Neutral (N): Transmission disabled, used for driving with the engine off.
* Park (P): The gearbox is locked, used for parking.
Advantages of automatic transmission:
* Smooth shifting for improved agility and performance.
* Automatic gear changes to reduce operator workload.
* Improved grip on various surfaces.
* Increased engine life due to reduced wear.