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

A Simple Guide to Benefits of Electromechanical Technology

Article Posted by Parker’s Electromechanical Team on Thursday, February 15, 2018, on the Parker Motion & Control Technology Blog

A Simple Guide to Benefits of Electromechanical TechnologyLinear actuators are typically grouped into two principal types: fluid power actuators that operate on differential pressure, and electromechanical actuators driven by an electric motor. Increasingly, electromechanical solutions are providing an attractive alternative to hydraulics in a wide and diverse array of automation systems.

Electromechanical systems offer:

  • Simpler and smaller installation
  • Greater flexibility
  • Quieter positioning and torque control
  • Lower energy costs
  • Less maintenance
  • Potential to provide more ATEX-rated solutions for use in explosive environments

Complete motion control

In complex applications, electromechanical solutions can be particularly advantageous as they provide control over the entire motion profile. Moreover, integral encoders accurately control speed and position, while some solutions can also control and monitor torque. Programmability means that motion and force profiles can be changed using software without having to shut down and reconfigure the machine.

In terms of energy consumption, unlike hydraulics, electromechanical solutions use power only when they are performing work, thus contributing to significant savings. Also, due to their minimal impact on the environment, solutions of this type are strongly preferred in applications where clean operation is important or desired.

An example case for electromechanical solutions is put by Industrie Cometto SpA, an Italy-based designer/manufacturer of trailers, semi-trailers and self-propelled vehicles, which wanted to replace hydraulic systems on its EMT (Electric Modular Transporter) to achieve greater flexibility in terms of speed and control, and make it suitable for use in ATEX classified atmospheres.

A Simple Guide to Benefits of Electromechanical TechnologyReplacing hydraulics

The traction and steering systems on the EMT are now equipped with Parker electromechanical products. Each transporter can have from four to 16 wheels, all of which have to follow a perfect trajectory to ensure coordinated motion. With this in mind, the drive system has to guarantee precision in terms of speed, position and torque control. An AC, three-phase, 2.3kW electric motor is fitted to the traction system on the EMT.

With regard to the steering system, the position of each wheel axle is controlled electronically using an encoder. Here, each suspension unit is linked to the load platform by a rotation system driven by a 1kw electric motor. The motor is controlled by an absolute encoder and managed by Cometto’s central processing unit.

Parker supplies the complete motor and drives packages for both of Cometto’s non-ATEX and ATEX EMT vehicles. For the latter, Parker provides its EX (explosion-proof) servo-motors with AC890 variable speed drives.

The EX series is a range of permanent magnet explosion-proof brushless servo motors characterised by excellent motion quality, dynamic acceleration/deceleration capabilities and high torque output over a wide speed range. Parker’s AC890 is a compact, modular system variable speed AC drive engineered to control speed and position of open-loop and closed-loop, single- or multi-motor AC induction or PMAC motor applications. The AC890 variable speed drive is compatible with any AC motor and many speed/position feedback options.

Ultimately, electromechanical solutions offer engineers a number of potential benefits over hydraulics that are proving difficult to ignore when it comes to new system designs. These can include one or many of quality, reliability, maintenance, performance, cost, ease-of-use, noise levels and operational response.

Learn more

EX-Series Explosion Proof (ATEX) Brushless Servo Motors

AC Variable Frequency Drives, kW Rated – AC890 Series
Article contributed by Edi Gherbezza, electromechanical, motion & drives
application manager & business development manager  for Motion Systems Italy

Meet BOB – The easy to use breakout boards shortening your time to market.

Trinamic Motion Control understand that time is a precious resource. Especially with technology, it’s important to drive the industry by reducing your time to market. That’s why they’re rolling out open source BOBs for our chips transforming digital information into physical motion.

Trinamic TMC-5072-BOBFrom now on, one single, easy to use electrical component is everything needed for rapid prototyping – you no longer have to worry about building a final design or soldering SMD components before testing a prototype. The BOBs can be used on a breadboard or with flying wires, as all sensitive signals such as sense lines are routed on the BOBs themselves.

The breakout boards are for anyone who needs a physical prototype fast, in order to have a Minimum Viable Product (MVP). BOB has everything you need to use the component, such as sense resistors, buffer capacitors and, in some cases, even power MOSFETs or Ethernet connectors.

Trinamic’s Technology Access Package (TTAP) provides the user with a sample code and API for each of the chips found on the BOBs. The comprehensive collection of technical support information and tools for Trinamic’s motor and motion control ICs found in TTAP not only simplify the (physical) design-in and bring-up, it also speeds up firmware development. All this can be transferred to a microcontroller or used with one of the Arduino samples – minimizing the time needed for prototyping.

All Trinamic BOBs are open source hardware, with a permissive license. If the design works for you, just take the design and paste it into your board design. Or simply copy the schematics – whatever best works for you.

Whether you’re an enthusiast tinkering away, a startup realizing its first MVP, or an international company creating the next groundbreaking application. Building, testing and reiterating your MVP doesn’t have to take long with Trinamic’s BOBs.

The BOBs will be rolled-out for all Trinamic motor and motion control ICs, with the following immediately available through distribution:


For more information on Trinamic products contact Micromech on 01376 333333 or sales@micromech.co.uk

Nippon Pulse SLP and SCR Linear Shaft Motor Stages

Nippon Pulse offers two types of linear stages – Acculine SLP stages and Nanopositioning SCR stages – both of which are high-precision, single-axis linear stages. Both include an integrated Linear Shaft Motor and encoder offering different levels of precision. Both types of stage are ideal for small-scale applications or applications with space limitations, due to their compact size. They both provide the speed and performance expected of linear servo stages.

Nippon - SCRSCR Sub Nano stages

SCR stages include an optical linear encoder for sub-nanometer resolution, along with an integrated cross-roller guide and motor cables. This stage produces extremely accurate results with no loss in stability.


Nippon - SLPSLP stages

SLP stages include a 1-micron resolution encoder, along with integrated bearings and a linear guide. The SLP is perfect for simplifying the transition from ball-screw systems, and provides an unmatched force-to-volume ratio.


Click here to view the Linear Stage Systems Catalogue

For more information on Nippon products contact Micromech on 01376 333333 or sales@micromech.co.uk

Select the Best Sealing and Shielding for Linear Mechanics in Harsh Environments

Article Posted by Electromechanical Team on Thursday, January 25, 2018, on the Parker Motion & Control Technology Blog
Parker Many factors must be considered when determining which linear actuator to use in an application. Besides technical specifications such as speed, acceleration and payload, there’s another critical aspect that must be considered – the application environment. In fact, if you do not account for the environment, the rest of your application requirements can be out of specification when using the actuator.
Application environment
Why are the details of an application’s environment so important?  Depending on the application, you may need to protect the actuator and its control from the environment. Electromechanical linear stages have critical, moving components that will only work properly within the correct environment. If you try to use the linear stage in the wrong environment, issues can range from the stage not working properly to causing damage to the unit that is beyond repair. If you have a “dirty” application (e.g., a cutting application that produces lots of scrap metal) the proper sealing and shielding are needed on the actuator to protect it from contaminants.

Parker However, it is not always the actuator that must be protected from the environment, but the opposite.  We know that linear stages will particulate over time due to normal wear and tear – no matter what application or environment. While we can minimize the amount of particulate from the actuator and increase its life cycle using proper seals and shielding, you must ensure the application’s environment is not compromised. Cleanroom or in-vacuum applications may require zero particulates, so it is critical that they use actuators with seals and shields to protect them. Remember, some linear mechanics are moving only microns at a time. Even the tiniest amount of contamination can compromise and ruin an application.

Environmental factors

Consider these Environmental factors when designing for an application:

  • Temperature
  • Exposure to gases other than air
  • Moisture presence
  • Radiation
  • Pressure level (does it need to be able to perform in-vacuum?)
  • Cleanliness (does it need to be rated for cleanroom use?)
  • Surrounding objects impacting performance (example – does another unit cause vibrations that will affect the linear stage’s specifications?)
  • And more

You must consider these factors from both sides. Will the temperature be too hot and cause my actuator to burn out? If my actuator is exposed to moisture without the proper seals, will it be damaged? Conversely, can the actuator react poorly with a chemical in the environment causing contamination throughout? Issues will arise in your application if you do not make sure the actuator and environment are compatible. To find that compatible actuator, you will need to understand its seals and shielding capabilities.

Sealing and shielding for protection

Parker There are countless harsh environments that linear mechanics can be used for, but how are the units protected to work properly? The answer is using sealing and shielding technologies. A linear mechanism is comprised of various components. When the assembly is complete, there can be parts critical to the drive train and bearings that are initially exposed. If nothing is done, a harsh environment will destroy the linear stage in short time. Conversely, if the environment is a cleanroom, the actuator can particulate and cause contamination. By adding seals and shields where necessary, those critical components of the actuator are no longer exposed to the harsh environment, and the linear stage can run as it was designed to perform. For clean environments, the seals and shields on the actuator are protecting the application’s environment, not the actuator itself.

Seals and shields are both in place to keep contaminants out of a bearing. External seals must be able to prevent contaminants from entering the actuator. Integral bearing seals need to keep contaminants out and lubricant in the bearing cavity. Seals in contact with sliding surfaces are called dynamic seals and are used to seal passages between machine components that move relative to each other either linearly or in the circumferential direction. These dynamic seals must retain lubricant, exclude contaminants, separate different media and withstand differential pressures. The materials from which the seal is made should also withstand a wide range of operating temperatures, and have appropriate chemical resistance.

Ingress protection rating

How do you know if a linear stage has the proper protection from its environment? The stage’s Ingress Protection (IP) rating will tell you this. IP ratings are defined levels of sealing effectiveness of enclosures against intrusion from foreign bodies (dust, dirt, etc.) and moisture. An enclosure rating takes the form of “IP-” followed by two digits, each of which has a specific meaning. The first indicates the degree of personal protection from moving parts and also the level of protection of the equipment from foreign bodies. The second digit defines the protection level that the enclosure offers for exposure to moisture in the form of drips, sprays, submersion etc.

A complete reference standard for IP ratings may be found in IEC 60529. Following are some basic guidelines:

 First Number  Characterization of ingress limit
 0  No protection
 1  Objects larger than 50 mm
 2  Objects larger than 12.5 mm
 3  Objects larger than 2.5 mm
 4  Objects larger than 1 mm
 5  Protected from dust (limited ingress)
 6  Dust-tight
 Second Number  Characterization of ingress limit
 0  No protection
 1  Dripping water – vertical
 2  Dripping water -up to 15 degree angle
 3  Water spray
 4  Water splash
 5  Waterjet
 6  Powerful waterjet
 7  Temporary immersion
 8  Continuous immersion
Checking the IP rating of an actuator initially can help rule out any that will not be suitable for the environment. It may also save you money. For example, the Parker 400XR Series has an IP30 rating. While it will not have any protection against moisture, it does have intrusion protection against fingers. The XE Series, an economical alternative to the XR Series, does not have an IP protection (i.e. 00). If there are concerns about injuring fingers, XR should be selected. However, if the intrusion protection is not necessary and the XE specs work for the application, the customer can save money by with the XE. Now if a customer needs protection against moisture as well, the XR Series is not the right choice. Instead, they should use the HMR Series, which has an IP54 rating.

ParkerCustom solutions

Parker offers a wide array of linear positioners suitable for applications in a variety of environments, even the harsh ones. Our IP rating differs from product to product and application to application, so we are confident the right fit can be found. Once determined, sealing and shielding guidelines are followed for all our linear mechanics to meet the required customer specifications. In addition to seals and shields, positive pressure ports can be included on linear stages as well. This allows customers to purge unwanted contaminants inside their unit, keeping the performance and life cycle at a maximum.

What if you are not certain which sealing and shielding technology is needed for their application? Parker will work directly with you to provide custom engineered solutions. We will discuss your requirements and can determine the best product to use based on the environment.  Forming this partnership throughout the process ensures you receive the best solution for your application  – which is Parker’s ultimate goal.

ParkerArticle contributed by Patrick Lehr, product manager for precision mechanics, Electromechanical and Drives Division North America, Parker Hannifin Corporation.