What is a Linear Actuator?

Article Posted by Jimmy Coleman on 23rd February, 2018 on Kollmorgen’s Blog in Motion



Answer: Quite simply, a linear actuator is a device that moves a load in a straight line.  Linear actuators come in many styles and configurations – our blog post today covers those actuators associated with motion control.



Linear actuators are an important piece of the motion control picture.  There are so many methods of creating motion using rotary motors that I won’t go into all of them.  I probably couldn’t even list all of them in one sitting.  But, linear ballscrew, lead screw, and belt drive actuators offer a unique solution to linear motion applications.  The main advantage, other than converting rotary motion into linear motion, is the fact that they are self-contained.

KollmorgenThere are a few general types of actuators, commonly specified by their primary mechanical components.  Electric cylinders are those actuators that have a cylinder much like a hydraulic ram, which is controlled by an electric motor.  Rodless actuators are those actuators that don’t have the protruding cylinder or ram.  These have a carriage that traverses the length of the actuator.  And precision tables, although basically the same principal as the rodless actuator, have very high positioning precision.  Precision tables are designed to be mounted to a granite table and hold tight tolerances for straightness, flatness, and axial accuracy and repeatability.

The mechanisms usually consist of a coupling or gear reducer, and a lead screw or belt drive system.  Some actuators have the motor directly coupled to the screw shaft, but more often, there is a gear reduction between the motor shaft and the screw shaft.  This can be performed using a set of gears or a timing belt with pulleys.  The gear ratio is typically a speed reduction, which multiplies the motor’s torque.  The overall speed of the actuator’s motion is limited by this gear ratio.

In Part 2 of our blog post on Linear Actuators, we will explore a variety of the mechanism types which are used most frequently in motion control applications.



About The Author

Kollmorgen Jimmy Coleman is a Systems Engineer in the L2 Technical Support team in Kollmorgen Customer Support.  He graduated from Virginia Tech in 1999 with a B.S. in Civil Engineering.  Prior to working at Kollmorgen, Jimmy worked for a small company doing electrical and mechanical design and fabrication of customized instruments for analyzing petroleum products.  Jimmy started at Kollmorgen in 2004.  He is heavily involved in fieldbus communication protocols, along with supporting mechanical, servo, stepper, and programmable products in various applications.  He enjoys the challenge of finding solutions for interesting applications.  Most of Jimmy’s time away from work is spent enjoying time with his family.  Some frequent activities include working on the house and cars, going bowling and roller skating, and going to the beach.  You can reach Jimmy here: Jimmy Coleman

Go big with the TMC5160 controller/driver IC

This single-axis stepper motor driver IC with serial communication interfaces is developed for 2-phase bipolar stepper motors with external MOSFETs for up to 20A motor current per coil.

trinamic_tmc5160It successfully combines our technological innovations into a single device that achieves a new maximum for motor voltage and current specs with external N-channel MOSFETs,” explains Michael Randt, Founder and CEO of Trinamic.“Ease-of-use was the guideline for our designers, as well as cost efficiency. By integrating a powerful stepper motor driver and a dedicated motion controller in one single chip, the TMC5160 directly transforms digital information into physical motion that’s smooth, precise and reliable.”

In fact, it’s so easy to use that you only need the target positions. All stepper motor logic takes place within the TMC5160 itself – there’s no need for software when driving NEMA17 up to NEMA34 and bigger motors. Connected to a host microcontroller through an industry standard SPI or step/direction interface, the TMC5160 performs all real-time position and velocity stepper motion calculations.

Extending the TMC2100, TMC2130, and TMC5130 family to higher voltages and motor currents, the chip packs the company’s successful SpreadCycle™, StealthChop™ and SixPoint™ technologies for microstepping with up to 256 microsteps per full step, silent operation and an advanced ramp generation profile maxing out the motor’s torque characteristics for rapid positioning. Designed for CNC machines, textile machines, lab automation, factory automation and other domains using powerful motors where smooth, quiet and precise motion is required.

To minimize the application development time, Trinamic provides the comprehensive application development package TTAP which includes code examples, EDA libraries, and reference designs. Fast evaluation is realized using Trinamic’s intuitive PC-based software TMCL-IDE and the modular evaluation kit.

The TMC5160-TA, evaluation board (TMC5160-EVAL), evaluation kit (TMC5160-EVAL-KIT) and a breakout board (TMC5160-BOB) is available now. For more information on Trinamic products contact Micromech on 01376 333333 or sales@micromech.co.uk

Electrak HD is the next generation of electric linear actuators from Thomson – Available with Higher Load Capacity and Synchronization Option

Electrak® HD – Smarter, Stronger, Longer

Thomson Electrak HDThe Electrak HD is a new range of electric linear actuators with onboard electronics, eliminating the need for standalone controls. These new higher power actuators are open to a wider range of hydraulic applications for electric conversion. They also meet the most extreme OEM component environmental acceptance tests, including IP69K.

The Electrak HD offers 50% higher load capacity, 60% longer stroke lengths than previous designs and is faster than the competition at comparable loads. In addition the onboard controls boast advanced control features.

Superior Performance

Higher power and longer stroke lengths enable Electrak HD to tackle applications outside the range of other electric linear actuators.

  • Higher load ranges up to 16 kN (3600 lbs.) are ideal for hydraulic-to-electric conversion applications
  • Stroke lengths up to 1 m (39 in.) for models up to 10 kN / 500 mm (20 in.) for 16 Kn
  • Efficient actuator design, including a high-quality ball screw, reduces current draw by up to 20%

Unrivaled Environmental Protection

Electrak HD is tested to meet and exceed the toughest OEM mechanical and electronic component acceptance tests on the market today.

  • IP69K (static), IP67 (static) and IP66 (dynamic) ratings prove Electrak HD can withstand the harshest environments
  • Capable of operating in a wide temperature range from -40°C to 85°C (-40°F to 185°F)
  • Salt spray tested for 500 hours
  • CE, RoHS and REACH (EU) compliant
  • Rated for IP-X6 (dynamic) during water splash at 10°C ( 50°F) and an equalized actuator temperature of 85°C ( 185°F)
For more information on Thomson products contact Micromech on 01376 333333 or sales@micromech.co.uk
Thomson Electrak