The transmission is connected to the engine primarily through a component called the torque converter in vehicles equipped with automatic transmissions, or a clutch in manual transmission vehicles.
In vehicles with automatic transmissions, the torque converter connects the engine to the transmission. This crucial apparatus uses pressurized fluid to transfer power to the gears. It effectively replaces the manual friction clutch found in vehicles with standard transmissions. A key function of the torque converter is that it lets the vehicle come to a complete stop without stalling the engine, unlike a manual transmission where the driver must engage the clutch pedal to disconnect the engine from the transmission when stopped.
Here's a quick look at the connection in automatic transmissions:
- Engine Output: The engine's crankshaft rotates, generating power.
- Torque Converter Input: This power is transferred to the torque converter's input side (typically via a flexplate).
- Fluid Coupling: Inside the torque converter, pressurized fluid acts as a coupling medium. As the engine spins, it pumps this fluid, which in turn spins the turbine connected to the transmission.
- Transmission Input: The torque converter's output shaft connects directly to the transmission's input shaft, sending power to the gear sets.
This hydraulic connection allows for smooth power transfer and allows the vehicle to remain stationary while the engine is running.
Key Aspects of the Connection (Automatic Transmission):
- Component: Torque Converter
- Mechanism: Pressurized Fluid
- Purpose: Transfers power from engine to transmission
- Benefit: Allows vehicle to stop without stalling (replaces clutch)
While the torque converter is the specific component highlighted in the reference, it's important to note that manual transmission vehicles use a different mechanism: a friction clutch. The clutch allows the driver to manually connect or disconnect the engine from the transmission for shifting gears and stopping.
