Skip to main content
Teacher Portal
Actuator

No matter how a robot moves, Newton's Law dictates it must have an actuator. The type of actuator depends a great deal on the function the robot will be doing.

There are two ways in which an actuator can move a component on a robot. One way is to have an actuator directly connected to the component. This is called direct drive. For actuators which have a spinning shaft, there is a second option which is called indirect drive. With indirect drive, the actuator’s shaft spins a system which transfers the force to the component on the robot. This system might use gears, sprockets and chain, pulleys and belts, or another type of power transmission between the actuator and the component it is moving.

It is necessary to consider how an actuator will be driven when designing manufacturing robotic systems. For example, if a robot needs to lift a very heavy load it may use hydraulics. If it needs to move parts very quickly it may use pneumatics.  However, nearly all robots use some type of electric motor as an actuator.  These actuators may be powering the robot component either by a direct drive or an indirect drive.  

Newton’s writing certainly applies to the V5 Workcell, which uses servo motors with an indirect drive gear system to move its arm.

Motivate Discussion icon Motivate Discussion

Question: What are actuators, how are they driven, and what factors would determine which would be used on a robot? How do these terms relate to the V5 Workcell?

Sample solution: Actuators like hydraulics, pneumatics, motors, stepper motors, and servo motors provide the force to move robots. They can be directly attached (direct drive) to the component they are moving or they can have their force transferred (indirect drive) through a system like gears, sprockets/chain, or pulley/belts. The V5 Workcell uses servo motor actuators with an indirect drive using gears.