Motorcycles without traditional clutches, such as some Harley Davidson models, typically use an automatic transmission system called a "torque converter." A torque converter is a fluid coupling that allows the engine's power to be transferred to the transmission without the need for a manual clutch. Here's how it works:
Power Transmission: The engine's power is transferred to the torque converter, which consists of an impeller and a turbine connected by a fluid-filled housing. The impeller is driven by the engine and generates fluid flow inside the torque converter.
Fluid Coupling: The spinning impeller creates fluid movement, which in turn drives the turbine. This fluid coupling allows the engine's rotational energy to be transmitted to the transmission.
Torque Amplification: The torque converter also provides torque multiplication, which allows the motorcycle to accelerate smoothly from a standstill. This is achieved by exploiting the fluid's ability to multiply torque as it passes from the impeller to the turbine.
Gear Shifting: Instead of a manual clutch, motorcycles with torque converters typically employ an automatic transmission system. The transmission can have multiple gears, which are automatically selected based on factors such as engine speed, throttle position, and vehicle speed. The transmission shifts gears by electronically or mechanically controlling the engagement and disengagement of clutches or bands.
Smooth Operation: With a torque converter, the rider can start the motorcycle from a stop without manually engaging and disengaging the clutch, as the torque converter allows for smooth power transfer. This makes it easier to ride, especially for those who prefer not to use a manual clutch.
It's worth noting that not all Harley Davidson motorcycles use torque converters or automatic transmissions. Many Harley models do have traditional manual clutches and sequential or manual transmissions, similar to other motorcycles on the market.