Spur gears are cylindrical gears with straight teeth that are parallel to the axis of rotation. They are commonly used in various machines to transmit power and motion between shafts. Their simple design allows for efficient power transfer, making them a popular choice in mechanical systems. These gears mesh directly with one another, which means they can produce a smooth and quiet operation when properly aligned. Spur gears are often found in applications like clocks, conveyor systems, and automotive transmissions, where they help control speed and torque effectively.