Belt and chain drives are essential components in mechanical power transmission systems, used to transfer motion and force between rotating shafts. Belt drives utilize flexible belts made of materials such as rubber or synthetic fibers, which run over pulleys to transmit power. They are known for their smooth operation, quiet performance, and ability to accommodate misalignment between shafts. Common types of belt drives include flat belts, V-belts, and timing belts, each suited for different applications based on load capacity and speed requirements. Chain drives, on the other hand, use metal chains that engage with sprockets to transmit power. They are favored for their durability, high load-carrying capacity, and positive engagement, making them suitable for heavy-duty applications. This page explores the principles of belt and chain drives, their types, functions, and applications in mechanical systems.