What Leonardo da Vinci invention was a spring-powered machine designed to generate continuous rotary motion?

Leonardo da Vinci investigated a spring-powered perpetual motion machine designed to generate continuous rotary motion.

His notebooks include studies of wheels, weights, gears, and springs that reflect an interest in whether a mechanism could keep turning indefinitely. Some drawings explore arrangements in which weights shift around a wheel, apparently creating an imbalance that would drive rotation. Other studies consider springs and mechanical cycles.

Leonardo ultimately recognized that these systems could not provide endless useful motion. Friction, air resistance, and energy losses prevent a machine from producing work forever without an external energy source. His later notes are often cited as evidence that he understood the practical limits of perpetual-motion schemes.

The idea should not be confused with an ordinary self-running clock or a machine that runs for a long time after being wound. Those devices consume stored energy. A true perpetual-motion machine would violate established physical principles by producing continuous work without an energy input.