What is a Linear Actuator?

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

Kollmorgen

 

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.

 

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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

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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