Go long! Selecting a long stroke electric linear actuator

Posted by Aaron Dietrich on
Go long.jpgSome linear actuator application requirements mean you have to go long. Long stroke, that is. Length of stroke is a critical factor in electric linear actuator selection. While some applications require moves of just inches or a few feet, others require moves of 10 feet or more. For an application requiring this kind of long stroke linear actuator, a belt driven rodless electromechanical actuator will be your solution.

When you’re specifying an electric linear actuator, it’s critical to select the right drive train (screw or belt) since the drive train’s responsible for both linear positioning and power transmission. Stroke length has a major impact on drive train selection. For a thorough review of power train selection, download our white paper. 

White Paper: Belt Driven vs Screw Driven Rodless Electromechanical Actuators

Long stroke = belt drive

Screw drives have many advantages and are right for lots of applications. They offer high-thrust capacity, plus great accuracy and repeatability. The service life of ball and roller screw drives is predictable using the L10 life calculation for ball bearings.

Belt drives, however, are available in much longer lengths than screw drives, making them ideal for long stroke linear actuator applications. The length of the stroke of a belt driven linear actuator is limited only by the ability to efficiently tension long strands of the timing belt. Plus, belt driven linear actuators are 90-93% efficient, high speed, easy to operate, simple to maintain and provide long service life.

Defining long stroke

How long is long, you ask. The answer: length is relative. Load size and weight, speed, and distance of travel all play roles in determining whether a given actuator can handle an application. That said, here are four applications that require long stroke lengths. Each uses a long stoke belt driven rodless electromechanical linear actuator.b3w15-shaltz-turbo-spray.gif

  • Spray Coating A spray head coats the inner and outer diameters of long pieces of tubular sheet metal. An electric linear actuator moves the assembly across a 74-inch stroke.
  • Cleaning Rollers A pulp and paper processor must clean pulp from rollers during the paper making process. Rodless electromechanical actuators carry the cleaning brushes 108 inches.
  • Palletizing A conveying system manufacturer uses a belt driven linear actuator to index can lids for a pick-and-place robot. The move is 120 inches, performed at a speed of 37.5 in/sec.
  • Munitions Assembly Large loads are moved along a rail system from one assembly station to another. Long stroke linear actuators power this transport system, covering distances of 120 inches, 228 inches and 288 inches between stations.

Our long stroke linear actuators

We offer a variety of electric linear actuator options for long stroke applications:

Learn more

Our white paper, Screw-driven vs. belt-driven rodless actuators: How to select drive trains for reliability, efficiency and long service life, provides more on selecting actuator drive trains. Download it here. 

White Paper: Belt Driven vs Screw Driven Rodless Electromechanical Actuators

Interested in electric linear motion? Join the discussion at our LinkedIn group. Just click here.

Topics: Actuator selection

Integrated servo motor/controller/drive saves cost and plant space

Posted by Nick Holmgard on
Conveyor_systemSpace is at a premium in most manufacturing operations. And of course, saving money is a constant goal. Plant managers are looking for ways to save money and space, so machine designers are tasked with creating ever more compact, affordable systems.

A new class of products addresses the needs for lower cost and efficient use of space: the integrated servo motor/controller/drive. These systems combine a servo motor and controller with a servo drive. They’re compact and eliminate the need for a drive cabinet.

We have designed an integrated servo motor/controller/drive that works with all our electric linear actuators: the new ACSI. Download our brochure here.

ACSI Integrated Servo Motor/Drive/Controller Brochure

We’ve solved a variety of challenges with ACSI, not all of them related to linear motion. Here’s an interesting rotary application challenge for an integrated servo motor/controller/drive that ACSI solved.

A rotary motion challenge

A conveyor and packaging systems OEM was using a lever arm to direct product from one conveyor line to a perpendicular conveyor. The application’s motion profiles required specific accelerations and speeds to prevent product damage while overall conveyor speed had to maximize production efficiency.

The existing motion control system used a traditional high-voltage drive, cables and servo motor. It was a costly solution, though, since the drive exceeded the application’s performance requirements and the system required electrical noise shielding with a separate encoder cable.

The OEM needed to lower the cost of the conveyor system and reduce the space taken up by the electrical cabinet, encoder and power cables.

ACSI and conveyor system

 

Integrated servo motor solution

 Tolomatic recommended the ACSI34 Basic for this application. This integrated servo motor and controller with servo drive provides cost savings of 60% over the previous system. The I/O and power cables are smaller and eliminate the need for a noise sensitive encoder cable. With no need to house a drive in an electrical cabinet, the integrated product saves significant space. The ACSI Basic was simple to set up and can be easily controlled using digital I/O or analog inputs.

ACSI: cost-effective and space-saving

ACSI - blue.jpgThe ACSI integrated servo motor is a cost-effective solution for automating additional axes of motion with simple control options via digital I/O or industrial Ethernet. It creates a space-saving machine design by eliminating the need for a drive in a cabinet. 

The ACSI can be controlled with simple digital I/O (24Vdc), analog input (0-10Vdc or 4-20mA) or robust industrial Ethernet (EtherNet/IP and Modbus TCP). Optimized for linear or rotary operation with built-in configurations for all Tolomatic electric linear actuators, the ACSI integrated servo motor/drive/controller creates motion quickly and easily. When ordered with a Tolomatic electric linear actuator, ACSI will be mounted to the actuator, configured and tested as a system.

The EtherNet/IP implementation is very robust with ODVA conformance and has passed an EtherNet/IP PlugFest event. It is an I/O assembly-based implementation with a high-performance integrated switch, allowing the ACSI to live on any network topology including ring topology with Device Level Ring support. Additionally, the ACSI has a keyed Add-on-profile (AOP) and a full suite of Add-on-instructions (AOI) for easy, seamless integration into Rockwell Automation PLCs.

Learn more

Download our ACSI catalog for a product overview.

ACSI Integrated Servo Motor/Drive/Controller Brochure

Interested in electric linear motion? Join the discussion at our LinkedIn group.  Just click here.

Topics: Actuator selection

Lightweight servo actuators lower robotic RSW costs

Posted by Bill Graber on
cars.jpgBuyers want sturdy, well-built cars, so the quality of welds that hold auto bodies together is crucial to vehicle manufacturers.  Manufacturers want strong welds that are consistently and accurately placed so the finished car looks both durable and attractive.

Welding robots for resistance spot welding (RSW) have been a boon to auto manufacturers because they provide consistent weld placement.  But all welding robots need actuators to carry and power the weld gun. Those actuators have a huge impact on the consistent quality of welds. They can also impact the cost of robotic resistance spot welding.

Either electric servo actuators or pneumatic cylinders can be used in robotic resistance spot welding; however, there are distinct advantages to going electric.  For a thorough review of these advantages, see our white paper. 

ServoWeld white paper

Electric beats pneumatic

Electric actuators outshine pneumatic systems when it comes to delivering weld nugget formation.jpgstrong welds consistently at a lower lifetime cost

  1. Weld quality: Servo actuators apply the right amount of force for just long enough. Weld timing and pressure can be controlled nearly infinitely.  

Pneumatic cylinders, on the other hand, depend on compressed air systems that deliver fluctuating pressure levels which can mean inconsistent weld quality. 

  1. Repeatability: Because electric actuators are programmable, weld quality is consistent and high.  Speed, force, and other parameters can be locked in. 

Inconsistent weld quality is a given with pneumatic cylinders because inconsistent pressure is a fact of life with compressed air systems. 

  1. Cost: Even though initially an electric servo actuator may cost more than a pneumatic cylinder, it will last longer (10-20 million welds versus 3 million). Also, electric linear actuators are more efficient, operating at 75-80% efficiency as compared to the 15-25% of pneumatic systems.

Finally, electric actuators can be re-programmed for product changeovers, avoiding the time and expense of making manual changes to pneumatic cylinders.

Lower the cost of robotic welding

Welding robots for RSW are expensive. Even the most efficient and effective electric linear actuator can’t get around the fact.  However, if a smaller robot can be used, robotic resistance spot welding costs come down.  A smaller RSW robot will need a lighter actuator.

SWA_SWB servo actuators for RSWOur new SWB and SWA servo actuators, part of our ServoWeld® product line, are lightweight, compact RSW actuators that can work with a smaller resistance spot welding robots. The ServoWeld Advanced (SWA) actuator incorporates our highest level of roller screw technology and delivers the maximum number of welds. The ServoWeld Base (SWB) actuator uses an alternate roller screw design to provide long life at a more economical price (better than other electric linear actuators with inverted roller screws or ball screws). The SWA and SWB can produce forces up to 4,000 lbf/17.8 kN, last 10-20+ million welds and hold +/- 3% force repeatability over the life of the actuator.

Find out more about the SWA and SWB by downloading our brochure. 

 ServoWeld SWA/SWB Brochure

Learn more

Download our white paper, Servo spot welding offers superior performance and lower lifetime costs for auto manufacturing, for a comparison of pneumatic cylinders and electric servo actuators for robotic RSW applications.

ServoWeld white paper

Interested in electric linear motion? Join the discussion at our LinkedIn group.  Just click here.

Topics: Actuators in Robotic Spot Welding

Roller screws for high force linear actuators. What type’s best?

Posted by Aaron Dietrich on
manufacturingStandard roller screw? Inverted? Now that electric linear actuators are being adopted for high force applications, there’s a debate about what type of roller screw is best.  Roller screw actuators can deliver forces of over 50,000 lbf (225.5kN), but there are different screw types out there. 

Selecting the best screw type for a high force linear actuator can seem a daunting task, but it doesn’t have to be. Start with our Guide on the three common screw types for electric actuators, their advantages and disadvantages. 

GUIDE Which screw? Picking the right technology

Then go deeper with this review of screw selection for high force linear actuators.

Roller screw benefits

A roller screw has triangular-shaped threads that mate with threaded rollers in theRoller_screw.jpg nut creating an extended contact zone.  The extended contact zone results in very high force transmission capabilities and dynamic load rating (life) in a more compact package than traditional ball screws.   

The use of these screws allows engineers to specify electric linear actuators in applications once dominated by hydraulic cylinders. Compared to a fluid-powered cylinder, an electric linear actuator powered by a roller screw is low-to-no maintenance, longer-lasting, capable of higher speeds and much more accurate. This kind of electric high force actuator offers the advantages of programmability, fast changeovers, easy data collection and leak-free operation.

Standard roller screwsroller_screw_cut-away.jpg

Usually, in a standard roller screw, the threads on the shaft and rollers are case hardened and then precision-ground.  This yields a deeply-hardened surface and precisely-matched components that maximize the force transmission capabilities of the screw and provide the highest Dynamic Load Rating (DLR).  These screws last longer, making them a better choice when it comes to long-term value. There are other methods, such as rolling and whirling, for creating the threads in roller screws, but the precision of the thread form is not as high.  This lessens the overall force transmission capabilities and Dynamic Load Rating (service life).

A standard roller screw that’s integrated into an actuator is easily re-lubricated from the actuator rod or an access port in the side of the actuator.  Easy re-lubrication can mean longer screw and actuator life. 

Inverted roller screws

Inverted-Roller-Screw

In an inverted roller screw the functions of the nut and screw are reversed -- the rollers move inside the nut. While the inverted design can save space, it creates some challenges with manufacturing the threads on an internal dimension (ID) of a tube.  While it is possible to precision grind the threads on the ID of the tube, it is much more expensive due to the longer grinding time required as compared to standard roller screws.  It is also possible to whirl and roll the thread forms on the ID of the tube, but these manufacturing methods are not as precise and will lower the overall force transmission capabilities and service life of the resultant product. 

An inverted screw that’s integrated into an actuator is more difficult to access for re-lubrication. Applying grease often requires disassembly of the actuator. 

DLR (Dynamic Load Rating) explained

roller screw chart1.jpg DLR is a bearing term that’s also used with electric linear actuators that have roller or ball screws.  Dynamic Load Rating is a theoretical, statistically-based value of the constant load that a ball bearing or power screw can carry for 1,000,000 revolutions with 90% reliability. The DLR of a product is usually provided by the manufacturer. The comparison in the table above shows a standard, precision-ground roller screw actuator from Tolomatic compared with a competitive inverted roller screw actuator.

Get everything you need

Screw selection is a critical factor when specifying electric high force linear actuators.  The two roller screw  types, standard and inverted, differ in terms of DLR and service life.  Standard design screws, with their precision-ground threads, provide maximum force transmission and life.

Tolomatic has a broad selection of electric high force linear actuators – both roller and ball screw. We use standard roller screws to provide machine designers the longest possible service life, and we manufacture our own to ensure the highest quality.

Learn more

Download our guide, Which screw? Picking the right technology, for an overview of the advantages and disadvantages of each screw type.

GUIDE Which screw? Picking the right technology

You can go deeper with our review of screw selection for high force linear actuators

Topics: Linear Actuator Application Tips, High force linear actuators

Electric linear actuator speeds up changeovers, lowers TCO

Posted by Nick Holmgard on
conveying system.jpgIf you’re designing for batch processing, no doubt product changeovers are on your mind. Switching a production line from one product to another can be slow and cumbersome. However, using electric linear actuators instead of pneumatic cylinders can streamline changeover and lower operating costs. Rather than the time-consuming, manual process pneumatic cylinders require, changes can be accomplished by just selecting a different program.

Time is money, as the saying goes, and it’s especially true in manufacturing. Reduce the time a process takes and you save time and operating costs. The concept of total cost of ownership (TCO) considers issues beyond a component’s purchase price like the downtime and labor costs associated with changing production set-ups. For a comparison of the TCO of electric and pneumatic actuators, download our white paper.

Total cost of ownership -  electric vs. pneumatic  actuators

Here’s how a conveyor manufacturer sped up changeovers and lowered production costs.

Quicker changeovers needed

A conveyor manufacturer was using pneumatic cylinders in their lane diverting application. The company wanted to reduce the time it took to change the line for new products and eliminate the errors that often resulted from adjustments made manually by operators. Both the change process and the errors were causing significant amounts of costly downtime, as much as six hours each time. Plus, the conveyor manufacturer’s customers complained of position “floating” due to pressure fluctuations in the cylinders’ air supply.

The manufacturer was looking for a programmable linear actuation solution that would streamline the process of changing a line. Because the conveyor systems operated in manufacturing environments, the manufacturer needed actuators with an IP65 ingress protection rating.  The manufacturer had standardized on Rockwell Automation AB PLCs.bottles-on-conveyor-ERDandACS.jpg

Electric linear actuators offer programmability

Electric actuation offered a solution to both the product change and position floating issues. Tolomatic engineers recommended that two stainless steel ERD15 electric cylinders be used for each side-guiding plate in the conveyor system. The ERD actuators are fully programmable so changeovers take seconds rather than hours. These electric rod actuators do not rely on compressed air (which may have pressure fluctuations) so there is no problem with position floating. The new actuators also reduce operating costs by eliminating maintenance and other downtime as well as increasing energy efficiency.

Customized motors with epoxy coating are used to comply with the requirement for IP65 protection. The ACS stepper drive with EtherNet/IP™ and Add-on Profiles (AoP) provides seamless communication with the manufacturer’s chosen Rockwell Automation AB PLCs. The ACS drives are daisy-chained in series to simplify communication cabling.

ERD electric cylinders

ERD_pneumatic_replacement.jpgERD low-cost electric cylinders can replace pneumatic cylinders when automating manual processes. ERD cylinders are economical and work with many NEMA and metric mount stepper and servo motors to create a flexible, powerful, yet cost-effective electric actuation systems.

Click here for a product catalog.

ERD Catalog

The ACS stepper drive, developed specifically for electric actuators, creates a lowACS stepper features.jpg cost, easy-to-use single axis actuator solution. You just select a Tolomatic electric actuator in the drive software to automatically set up most of the necessary parameters to create motion in the desired linear units (mm or inch). ACS drivers/ controllers are available with NEMA 11, 17, 23, and 34 size stepper motors with options for gearheads, inline brakes and encoders.

Click here for a catalog. 

Download the brochure

Learn more

Download our white paper, Electric actuators vs. pneumatic cylinders: A comparison based on total cost of ownership.

Total cost of ownership -  electric vs. pneumatic  actuators

Topics: Actuator selection, Actuators in material Handling

Acme, ball and roller screws for electric linear actuators

Posted by Igor Glikin on

yWhen you’re specifying a screw-driven electric linear actuator, you’ll need to screws for linear actuators.jpgconsider the type of screw that best meets the needs of your specific application. Some manufacturers give you a choice so you can tailor the device precisely, and that’s a good thing since applications differ widely.

The basic types you’ll have to choose from are roller screws, ball screws and acme screws.  There’s quite a lot a machine designer needs to know about these electric actuator screw types and how to select the right one.  We offer a guide that helps your decision-making.

GUIDE Which screw? Picking the right technology

Roller Screws

roller_screw_cut-away.jpgRoller screw actuators are high force linear actuators that can achieve forces exceeding 50,000 lbf (225.5kN). Because of their high-force capabilities, these electric linear actuators  are now used instead of hydraulic cylinders in many applications because  they offer programmable motion control and lower cost of ownership.

These screws (also called planetary roller screws) have triangular-shaped threads that transmit force to multiple threaded rollers in the nut. Their high force transmission capabilities result from the fact that the rollers have significant contact with the screw threads. These screws and the actuators they power are screw comparison chartlong-lasting, acccurate, capable of high speeds and quick acceleration, and require little maintenance.

They are available in many diameters and leads.

Ball Screws

Ball screws actuators are moderate-to-high force linear actuators and are popular since they offer good performance at an affordable purchase price.

ball_screw.jpg

Ball screws get their name from the re-circulating ball bearings that fit between the screw and nut threads. The ball bearings transmit force and relative motion efficiently as they roll through one or more circuits in the nut. Like roller screws, ball screws also are available in many leads and diameters.

Ball screw actuators have moderately high thrust capabilities and predictable service lives. On the down side, some ball screws can be back driven easily (depending on the lead), and most produce an elevated level of noise in operation. They’re ideal for applications that require high duty cycles, moderately high thrust and high speed.          

Acme Screws

acme_screw.jpgAcme screw actuators operate quietly and are usually low cost. Acme screws come in a variety of leads and diameters to fit many applications. Nuts can be made from metals (which require lubrication to overcome friction) and self-lubricating plastics.

Acme screws are very strong due to their trapezoidal tooth form; however, they can be very inefficient.  Acme screws need high motor torques to drive them because of the friction inherent in the sliding action between screw and nut. Because of this friction and thread geometry, acme screws can reduce or eliminate back driving.

An acme screw is a good choice in linear actuator applications that require low speeds and duty cycles. Because so many variables (nut material, environmental factors and the demands of the application) affect the wear characteristics of acme nuts, it can be difficult to predict the service life of these screw/nut systems.

Insist on choice

The three screw types differ in their capabilities.  Each has advantages and disadvantages depending on the parameters of an application.  We recommend you look for an actuator manufacturer who offers you a range of screw type choices so you get an actuator that’s tailored to your needs.

Learn more

Download our guide, Which screw? Picking the right technology, for an overview of the advantages and disadvantages of each screw type.

GUIDE Which screw? Picking the right technology

Topics: Linear Actuator Application Tips

Machine design, clean in place (CIP) and linear actuators

Posted by Aaron Dietrich on
automated clean in place system.jpgKeeping clean is important, right?  Well, in food and beverage processing and pharmaceuticals manufacturing keeping equipment clean is essential.  Cross-contamination among batches causes problems, and food or beverage residue can grow harmful microorganisms. Many plants have clean in place (CIP) systems that deliver cleaning tailored to the needs of the facility including cleaning action (force, turbulence, direction), timing/duration (when, how often, how long), temperature, and type/strength of cleaning agent.

When you design equipment for these industries you need to keep cleanability in mind.   Even components like linear actuators must stand up to cleaning procedures.

If you need actuators that can handle these cleaning processes, we offer this white paper that explains the factors to consider when selecting actuators for washdown environments like those generated by clean in place systems. 

Evaluating linear actuators  for food and beverage  processing

Articlesfood and beverage processing.jpg

Cleaning in place is a complex topic that gets even more complicated when you add current concerns about process optimization and regulatory compliance.  As a machine designer, it helps to understand the basics at least.  These articles should help.

  1. What Is Cleaning In Place And How Does It Work? Process Worldwide, June 2011.  A great place to start.
  2. Tip Of The Week: CIP Vs. COP AIB International, Food First blog.   A blog post overview of the differences between clean in place (CIP) and clean out of place (COP) systems.
  3. Best Practices of Automated CIP Systems Food Quality & Safety, 2014.  A magazine article that provides a good explanation of how these systems work.
  4. Hygienic Design of Equipment in Food Processing Food Safety, 2003.  Magazine article on design considerations.
  5. Good Manufacturing and Material Selection in the Design and Fabrication of Food Processing Equipment Engineers Edge.  Article published on this web portal.

Linear actuator design factors

Clean in place procedures like washdowns are hard on automation equipment, including linear actuators. Moisture and caustic solutions can corrode parts, short out electrical circuits and impair functioning. To avoid these issues, look for linear actuators that stand up to these conditions with designs that:

  • Resist corrosion – Stainless steel is often used for bodies and motor housings. Or food grade epoxy may be used instead. Fasteners, seals and gasketing also need to resist corrosion.
  • Shed moisture and contaminants – A rounded body design eliminates crevices where moisture and food particles can collect. This and a water-shedding surface means contamination won’t linger on the actuator after cleaning.
  • Protect components from moisture damage – Because only the rod opening needs to be sealed against moisture and particles, and they can be fabricated from corrosion-resistant material, electric rod actuators are better suited to washdown conditions than are rodless electromechanical actuators.

CIP-compliant electric actuators

ERD_SS2_and_USDA_features.jpgYou can count on us for a wide range of compliant linear actuators. Our ERD hygienic electric actuators are approved by 3A and USDA for food and beverage applications. These IP69K, stainless steel electric actuators offer up to 7868 lbf (35 kN) of force and are the perfect solution for food and beverage processing applications including those where higher forces are required.

Our IMA food grade servo actuators offer sanitary protection in wash-down food grade IMA features.jpgapplications. The IMA food grade product family features a white epoxy food grade coating and food grade grease. Models are available with stainless-steel fasteners, rod and rod ends. Using the same integrated servo motor design as IMA servo actuators, they offer a compact footprint and are available in both ball and roller screw configurations. IMA food grade servo actuators provide forces up to 6875 lbs (30.6 kN) even in high duty cycle applications.

Learn more

For further information on selecting actuators for these challenging applications, download our white paper, Evaluating actuators for washdown in food and beverage applications.

Evaluating linear actuators  for food and beverage  processing

Topics: Actuator selection, Actuators in Food and Beverage Processing

Ball and roller screw linear actuators: How to compare service life

Posted by Aaron Dietrich on

manufacturing equipment.jpgWhen you’re designing equipment, you ‘ll probably be asked, “How long will this machine last?” And even if you’re not asked outright, you know service life is an essential consideration. It’s a critical factor you consider when sourcing components.

Electric linear actuators are important components in many machines, and the “how long will it last” question is a familiar one. If it’s a ball or roller screw actuator, you can use a formula to help estimate life based on load – the same formula used to estimate bearing life.  This Guide from Tolomatic explains how to use this formula to calculate L10 life for electric linear actuators.

Actuator Life Guide

The Guide shows you how to estimate life in units of travel and units of time.  It even explains how to compare the estimated life of two different actuators.  Here’s a summary, starting with a review of terms.

Important terms

Dynamic Load Rating (DLR) is the constant load under which a ball bearing device will achieve 1 million revolutions (rotations). The manufacturer usually provides this information.  It’s represented by the letter C.

L10 (or B10) Life is the number of revolutions which 90% of a group of identical actuators have the statistical probability to achieve (or at which 10% can be expected to fail). The calculation assumes a group of identical screw actuators operating under the same conditions.

Comparing actuatorsElectric rod actuator

RSX rod actuatorLet’s say you’re considering two actuators for an application.  It’s important that you compare the estimated service life (L10 life) of each alternative so you can identify which one will fit your application's needs best. 

Use this formula when you're faced with this situation:

Life comparison of products A vs. B =

(DLR A / DLR B)3 • (Screw Lead A / Screw Lead B)

Use the higher Dynamic Load Rating (DLR) as DLR A.

This formula can be used to compare ball vs. roller screw actuators, two different sizes of the same model, two different actuators from the same manufacturer or actuators from two different manufacturers.

Examples

When the actuators have the same screw leads – DLR A (8000 lbf); DLR B (4000 lbf); both with 5 mm lead

 A vs B = (8,000/4,000)3 • (5/5) = 8 • 1 = 8

This means product A has an estimated 8 times the L10 life of product B.

When two actuators have different screw leads – DLR A (8000 lbf) w/ 5 mm lead; DLR B (4000 lbf) with 10 mm lead

A vs B = (8,000/4,000)3 • (5/10) = 8 • 0.5 = 4

This means product A has an estimated 4 times the life of product B.

Why do we care about screw leads? Because DLRs are based on 1 million screw revolutions, life must be normalized for different leads.

Use with caution

There are two things to keep in mind when using this life calculation:

  • The first is that the L10 formula and this comparison formula give you theoretical estimates of service life only.  These are not guarantees.
  • The second is that load is just one factor affecting actuator life. Other things that can negatively affect life or cause premature failure include incorrect mounting/alignment, lubrication starvation, temperature and other environmental factors, like corrosive agents.

Learn more

For further explanation of the L10 life calculation, our guide, Actuator Life: How to estimate for ball and roller screw actuators, can be downloaded here. 

Actuator Life Guide

Topics: Actuator selection

Happy Holidays

Posted by Tolo Matic on

Ring bells, ring

Tolomatic 2016 holiday greeting

Wishing you lots of joy this season.

Topics: News and Noteworthy

Corrosion resistant integrated linear servo actuator is high force

Posted by Nick Holmgard on

aerospace mfrg.jpgThe electric rod actuator is an industrial workhorse, one you’ll find in a wide range of machine tool, conveying and positioning applications.  A familiar mechanism, yes. But identifying one that’s compact, corrosion resistant and can deliver high force is a tall order. A corrosion resistant integrated linear servo actuator can be the answer.

When it comes to corrosion resistance and selecting the right electric actuator for the job, a machine designer needs a thorough understanding of the specific industrial environment. Once you’ve identified all the corrosive substances, the IP (Ingress Protection or International Protection) rating system offers a way to make the best equipment selection. Although the system was originally developed for enclosures, it also can be used to match electric linear actuators to environmental conditions.

If you’re not familiar with the IP rating system, download this white paper from Tolomatic. 

IP Ratings White Paper

Welding application calls for high force, corrosion resistance

A manufacturer was welding titanium aerospace components.  The application called for several electric linear actuators to secure the parts, holding them in place for welding.  Positioning accuracy was critical, space was limited and the actuators needed to deliver the force to hold the components in place. A further complication: the process used deionized water for cooling, a substance that is corrosive to most materials including anodized aluminum.

This application needed high force linear actuators that were compact, corrosion resistant and highly accurate.

Integrated, high force linear actuator is solutionIMA servo actuator - aerospace manufacturing.gif

The manufacturer’s design engineers accepted our recommendation of IMA33 integrated linear servo actuators. IMA series actuators have integrated servo motors that deliver superb positioning accuracy. The integration of the servo motor and actuator mechanism creates a space-saving, compact linear actuator system.  IMA high force linear actuators deliver the clamping force needed in the application.

Additionally, the IMA integrated linear servo actuators were given special stainless steel housings designed with an IP69K rating to withstand the moisture and corrosion of the cooling process.  (Generally, the first number in an IP rating indicates the level of protection (0-6) against solid particles. The second number is the level of protection (0-9K) against liquids.)

These corrosion resistant actuators provide long life even in harsh conditions. The actuators’ compact design helps minimize machine footprint. Excellent positioning accuracy and high clamping force improve weld quality and yield.

IMA integrated linear servo actuator has unique design

ima servo actuator featuresThe IMA  integrated linear servo actuator features a compact, heavy duty package.  The integrated servo motor provides excellent positioning accuracy and is fully programmable. Available in both ball and roller screw configurations, IMA integrated servo actuators can provide forces up to 6875 lbs (30 kN). Plus, IMA servo actuators offer seamless integration with the Rockwell Automation Kinetix platform.

This unique integrated servo actuator design eliminates:

  • Motor couplers, adapters, timing belts, gear boxes
  • Unneeded assembly labor
  • Forced air or water cooling
  • Hydraulic systems
  • Pneumatic systems
  • Need for multiple vendors

For an overview of IMA integrated electric rod actuators, download our catalog.IMA Linear Servo Actuators Catalog

Learn more

For further explanation of the IP rating system, our white paper, IP ratings and the manufacturing environment: How to apply linear actuators for quality, safety and long service life, can be downloaded here. 

IP Ratings White Paper

Topics: Actuator selection, High force linear actuators