Many factors come into play when determining how to effectively apply electric linear actuators into your machine design. For example, what is being moved? How fast does it need to be moved? How repeatable does it need to be positioned? How much does it weigh, and how much force needs to be applied? Is the load supported by a bearing or is the actuator needing to provide all the support? How much space is available? All these questions need to be answered and taken into consideration when selecting the proper electric actuator.
Types of Electric Actuators
Generally speaking, there are two types of electric actuators used for providing electric motion: rodless and rod-style electric actuators:
Rod-style actuators are the form factor we tend to be most familiar with as they look most like traditional pneumatic or hydraulic cylinders. These actuators are driven by a screw and typically provide higher forces for pushing, pulling, or pressing applications and normally rely on the load to be supported by an external bearing system.
Rodless actuators usually have an internal guidance or bearing structure to independently support the load that is to be moved. Since there is no rod in the way, these actuators tend to take up less space compared to their rodded counterparts. Rodless actuators can be either screw-driven or belt-driven, and the need for which is determined by the application or the questions previously mentioned. As a general rule, belt-driven actuators allow for longer lengths and higher speeds.
Rodless screw-driven electric actuators are commonly used when there’s a high force component to move or when a very high degree of repeatability is required.
How To Choose The Right Electric Linear Actuator
The key to a successful deployment of electric motion technology is making sure the electric actuator is sized properly. Improperly sized actuators and associated controls (motors, amplifiers, etc.) can be the difference between a successful project and a costly mistake.
At a minimum, you will need to know the load weight, thrust force, index distance, required speed and the details of the mechanical power transmission components of the actuator such as screw diameter, lead or pulley diameter, and belt pitch along with any external gear reduction that’s included. Most manufacturers offer a sizing tool designed around the manufacturer’s products that will guide you step-by-step through the process using your application data.
While applying the appropriate electric motion control system can seem to be a complicated task, with some guidance from experienced application engineers and the help of system sizing software, designing an electric motion control system for your machine design has never been easier.