When designers and integrators need simple, flexible and compact linear actuation, they often turn to stepper motor linear actuators (SMLAs).The high configurability of SMLAs is among their greatest virtues, but sorting through myriad configuration options to tailor the optimal solution for a particular application can be a challenge for even the most seasoned motion engineer. Understanding the unique capabilities and limitations of each type of SMLA will make it easier to take maximum advantage of their wide range of flexibility.
Why SMLAs?
With the electromechanical cylinder (EMC), the company began electrifying actuators in 2007. These actuators replaced the conventional pneumatic solutions that had a higher energy consumption. In 2018, Bosch Rexroth presented the integrated measuring systems IMS, integrated into linear axes. The solution is largely immune to interference and offers high precision and integrability.
Many factors make SMLAs desirable for linear actuation, with their high levels of customization and configurability being the biggest. Their efficient design enables configuration of countless motor, lead screw and lead nut options into a unique assembly for each application.
SMLAs are also popular because the stepper motor affords a basic level of control without requiring external feedback devices such as encoders. The designer can program a stepper motor to move to an exact position at various resolutions without requiring any feedback to a driver or controller. This can make the overall cost and complexity lower than servos, brushless DC and other motor options.
Stepper motors and lead screws are also naturally compatible, which contributes to the high configurability of the SMLA. This natural fit is evident when it comes to optimal speed ranges, load capacities and positional accuracies.
Additionally, lead screws and stepper motors offer many available options for customization. Lead screws, for example, can be customized for end-machining, coating, accuracy, thread form and length, while stepper motors offer options to optimize motor windings for torque and speed, and to specify application-specific cabling, connectors, encoders, and end cap machining. Integrating stepper motors with lead screws dramatically increases the number of possible designs.
