Traditional step motor systems offer many benefits for an automation engineer looking to accurately and repeatedly position a load. This class of motor is traditionally considered to be a go-to motor for engineers because they are easy to set up, maintain, and troubleshoot. Their simplicity comes with trade-offs though, and some of those trade-offs require special attention. For example, step motors are traditionally run open loop, which means that if the torque demand from the machine is greater than the motor can produce, the motor either loses position or stalls. Unless there’s a feedback device—like an encoder—attached to the rear shaft of the motor, the drive/controller isn’t aware that the motor has lost position or stalled, which can cause numerous problems for machine performance. Additionally, open loop step motors typically run hotter than other types of motors because they always run at full current, regardless of load conditions—this also causes the system to have significantly higher energy consumption.
A newly released motor technology from Applied Motion Products®, and provided by PBC Linear®, referred to as StepSERVO™ wraps a step motor and encoder inside a servo control loop improving the overall performance of open loop systems substantially. First, closing the loop around the step motor and encoder provides a peak torque range for the step motor that is well beyond the maximum torque range of the open loop motor and helps maintain accuracy. This increases the available torque of the step motor by as much as 85% at speeds under 750 rpm. The new system also reduces heat in the motor by regulating the current in relation to the torque demand of the load, which in turn lowers energy consumption by up to 67%. All of the benefits of closed loop stepper control are a part of the StepSERVO closed loop stepper system initiative. For more information on how StepSERVO closed loop stepper systems can improve your next machine design, download the white paper, watch the webinar, or watch the video.
StepSERVO closed loop stepper technology is available with PBC Linear’s SIMO Series and Compact Series actuators, providing a complete mechatronics solution.
PBC Linear®, a Pacific Bearing Company, is the world leading manufacturer of the Simplicity self-lubricating bearings based in Roscoe, Illinois. With over 30 years’ experience in linear motion and bearing technologies, PBC has a wide range of solutions designed to solve difficult linear motion applications.
PBC Linear®, SIMO® are registered trademarks of PBC Linear and/or PBC Lineartechnik GmbH.
Applied Motion Products® is a registered trademark, and StepSERVO™ is a trademark of Applied Motion Products, Inc.
Applied Motion Products
National Marketing Director