What distinguishes a belt drive from a chain drive?

A belt drive is distinct because it utilizes a flexible belt made from materials such as rubber, leather, or fabric to transmit power between pulleys. This method of power transmission allows for smooth and quiet operation, as well as the ability to accommodate variable distances between shafts without the need for tensioning equipment that a chain drive might require. The flexibility of the belt also contributes to its capacity to absorb shock loads, reducing wear on components.

In contrast, a chain drive relies on metal links and is typically used for more robust applications where higher torque or precise positioning is essential. This fundamental difference in materials and design defines how each system operates and serves different mechanical applications. The other options touch on aspects related to maintenance or efficiency, but they do not capture the core structural and operational difference that sets a belt drive apart from a chain drive.