#mechanical drive

• Act — To carry out a conscious activity, to undertake an action, or to do something with a specific purpose; to exert a force, influence, or structural pressure upon an object or phenomenon. In a technical or legal sense, it means to set an electronic mechanism in motion or to initiate a legal procedure (a lawsuit) against someone.
• Self-propelled — Self-propelled, benefiting from an engine and an internal structural energy source; a machine, vehicle, projectile, or technical system capable of autonomous movement on roads, rails, or in space, without requiring towing, pushing, or a secondary towing vehicle. In industrial and military terminology, it describes a wide range of equipment (such as howitzers, combine harvesters, or cranes) mounted on its own self-propelled chassis.
• Propulsion unit — 1. (As a neuter noun) A mechanical device, engine, or complex structural technical assembly capable of generating and transmitting the pulling or pushing force required for the autonomous movement of a body or vehicle. 2. (As an adjective) Serving for self-propulsion; possessing the capacity to generate independent movement through its own energetic forces.