What is a round device that is attached to a shaft and driven by a belt called?

The round device that is attached to a shaft and driven by a belt is known as a pulley. A pulley serves as a wheel that can redirect or change the direction of force, allowing for the transmission of power through belts. It is commonly used in various mechanical systems to lift loads, facilitate movement, and transmit motion efficiently.

In systems where belts are used, pulleys are essential components that allow for the transfer of energy from one rotating shaft to another. They come in various sizes and configurations, depending on the application they are designed for. The effectiveness of a pulley in mechanical applications stems from its simplicity in design and its ability to work in conjunction with other components such as belts and shafts.

Understanding the role of a pulley within the context of machinery is vital, as it plays a significant role in efficiency and mechanical advantage in engineering applications.