Posts Tagged 'Linear Actuator'

New High Force RSA-HT Actuator from Tolomatic

Tolomatic RSA-GSA Series

Tolomatic RSA-GSA Series

Tolomatic’s RSA product line has undergone some enhancements to increase the allowable torque and force on the 32, 50 and 64 sizes.  The allowable force has increased from 7,000 lbf to 12,900 lbf.  Additionally, an IP65/67 option was added to this product line for wet/dusty applications such as outdoor environments.

New Features on 32, 50, 64 sizes:

  • IP67
  • Lubrication port
  • Purge / Breather port
  • Gear boxes on RP motor mounts
  • Larger size motors

Click on the link below to view the specification on these models-

http://www.electromate.com/products/series.php?&series_id=101882

For more information, please contact:

EDITORIAL CONTACT:

Warren Osak
sales@electromate.com
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699
www.electromate.com

Tags:  Linear Actuator, Tolomatic, Electromate, RSA-HT, Actuator, RSA series

 

A Comparison of DC Linear Actuators with DC Linear Motors

New article from maxon motors

Factory automation and robotic application engineers are often faced with the challenge of requiring fast, accurate and powerful linear actuation within a small allocated volume.  The two most commonly available technologies are rotary DC motor driven actuators and linear DC motor actuators.  This article provides details on the advantages and disadvantages with all technologies. 

Click on the link below to download the article.

http://www.electromate.com/db_support/downloads/Maxon-DC-actuators-vs-DC-motors.pdf

 

Tags:  maxon, maxon motor, maxon DC motor, Electromate, servo motor, BLDC motor, brushless motor, flat motor, pancake motor, automation, electric motor, motion control, linear actuator, linear motor

 

 

Linear Actuator Selection Tips: Rod or rodless

When you need to specify a linear actuator, you want to do it right.  Some basic decisions come first.  Like electric or pneumatic.  See Tolomatic’s recent blogpost for an overview of the advantages and disadvantages of pneumatic versus electric linear actuators.

If electric is selected, you’ll next need to decide if a rod or rodless linear actuator is the best choice.  Tolomatic offers both types of electric linear actuator, so you can count on us for motion control advice and application expertise.

Selection tips

Here are our tips for specifying the right electric linear actuator for the task.

1.    Calculate size for electric, rather than fluid power  When using an electric linear linear actuator sizing softwareactuator don’t fall into the common fluid power practice of oversizing the cylinder. Pneumatic linear actuators are usually lower cost so a bigger cylinder won’t blow the budget.  However, oversizing can be costly when specifying an electric linear actuator since the purchase price may be higher.  Take advantage of sizing software offered by manufacturers to get the right size linear actuator for your application.

2.    Calculate loads precisely  If you know the weight and size of the load, how far it needs to travel and how fast it needs to move, you can accurately specify actuator components, like screws, bearings and motors.  This is critical because if these components can’t handle the stresses of the application, the system may not operate properly.  Accurately specified components mean longer service life for the linear actuator. 

3.    Factor in the duty cycle  Duty cycle for a linear actuator is the ratio of operating time to resting time.  It’s expressed as a percentage.  Accuracy in calculating duty cycle means you can spec the right actuator – one that lasts. 

4.    Set critical speed limits  High speed may be desirable but in screw-driven linear actuators lead screws have critical speed limits.  If the screw is required to operate at or beyond the limit, it will oscillate, causing noise and vibration.  Long-term effects could be premature wear and even catastrophic failure. 

5.    Factor in the environment  Extreme heat and cold will affect linear actuator linear actuator washdowncomponents. Moisture, dust or corrosive agents can cause problems.  If a linear actuator is in a washdown environment there are special material and design issues to consider. 

6.    When it comes to the drive system, consider more than footprint Reverse parallel motor mounting has the appeal of saving space, but power transmission through belts or gears may make these configurations less powerful and efficient.  Often only an inline motor configuration can deliver the speed and thrust required. 

7.    Match life expectations with actuator capabilities  An electric linear actuator will fail if its drive or carrier bearing system is over-stressed by the load and the speed at which it operates.  Simply put, if the application requirements exceed the actuator’s capabilities, it will die an early death.  Specify a linear actuator that’s suited to the task or be prepared to replace the actuator early and often. 

Special tips for rod actuators

Because an electric rod actuator pushes or pulls a load, there are two special considerations to keep in mind when specifying his type of actuator for an application.

1.    Avoid side loading  Electric rod actuators are prone to damage and wear when they Rod and rodless electric linear actuatorhave to deal with even moderate side loads.  They do not provide much support to a load especially as the rod extends.  The weight of the load can actually deflect the rod, causing wear and tear on seals and bearings.  This deflection can cause accuracy problems as well. (Just look at the worried fish in the cartoon.)

2.    Keep total envelope size in mind.  There’s a difference between the overall length of an electric actuator and its working stroke length.  You’ll have fit problems if you don’t keep both in mind.

Special tips for rodless actuators

A rodless electromechanical linear actuator cariesy loads and is subject to different stresses than its rod-style counterparts. Here are two tips for specifying rodless actuators.

 1.    Calculate moments (torques)  There are three axes to think about.  Since rodless electro-mechanical linear actuators carry loads, stresses will be placed on the bearing system for the actuator’s load-carrying platform.  You can only specify the right actuator for an application if you’ve calculated roll, yaw and pitch.

2.    Mounting makes a difference  Mounting is always critical but especially if you need a long-stroke rodless linear actuator. If this is the case, make sure you factor in enough support points to ensure rigidity. Also, make sure the mounting surface is straight and flat and there is room for the actuator and motor combination.

electric linear actuatorTolomatic solutions

Tolomatic offers a broad selection of both electric rod linear actuators and rodless electro-mechanical actuators.  Click on the link below for additional information on Tolomatic’s line of linear actuators.

http://www.electromate.com/products/?partner=1175527175

For more information, please contact:

EDITORIAL CONTACT:

Warren Osak
sales@electromate.com
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699
www.electromate.com

 

Tags:  Electromate, Tolomatic, Linear Actuator, Electric Linear Actuator, Rodless Cylinder, Rod Style Cylinder

 

How to Select the Right Screw for your Linear Actuator

PowerPoint Presentation by Gary Rosengren, Director of Engineering at Tolomatic

The lead screw is an essential component in many electric linear actuators.  When selecting the type of lead screw a linear actuator should have, you need to strike a balance between purchase price and performance characteristics to get full value.

This new slideshow from Tolomatic shares the advantages and limitations of acme, ball and roller screws (the three screw types used in linear actuators.)  The slideshow also describes the application characteristics most suited to each screw type.

Acme Screws

acmme screw for linear actuatorAcme screws have a trapezoidal tooth form that’s very strong.  They come in a variety of leads and diameters to fit many electric linear actuator applications.  Nuts can be made from metals (which require lubrication to overcome friction) and self-lubricating plastics.

Acme screws operate quietly and are usually low cost.  They can be very inefficient because they need high motor torques to drive them due to the friction inherent in the sliding action between screw and nut.  But because of this friction and thread geometry, acme screws may reduce or eliminate back driving.

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

Ball Screws

Ball screws are very popular in linear actuators.  They get their name from the re-circulating ball screw for linear actuatorball bearings that fit between the arch-shaped screw and nut threads.  The ball bearings transmit force and relative motion very efficiently as they roll through one or more circuits in the nut.

Ball screws are available in many diameters, leads and accuracies.  Under ISO 3408, they’re classified by lead accuracy in one of five grades – 1, 3, 5, 7 or 10 – with grade 1 being the most accurate.

Ball screws have higher thrust capabilities, longer service lives and higher efficiency than acme screw systems.  On the downside though, some ball screws can be back driven easily (depending on the lead), are higher cost and can be noisy.  They’re ideal for applications that require high duty cycles, high thrust and high speeds.

Roller Screws

roller screw for linear actuatorRoller or planetary screws have triangular-shaped threads which match up with multiple threaded rollers in the nut.  These rolling elements create a highly effective system for transmitting force, even better than that of a ball screw.  Like ball screws, roller screws are classified by lead accuracy into five grades.

Roller screws have very high force transmission capabilities since the rollers have significant contact with the screw threads.  They come with a higher price tag though, which is balanced by the fact that they are long lasting, capable of high speeds and quick acceleration, and require little maintenance. Some roller screws may be back driven, though, depending on the lead.

Roller screws are best suited to applications where their high performance and long service life outweigh their initial purchase price.

More information on Tolomatic’s Product Family can be viewed at-

http://www.electromate.com/products/?partner=1175527175

For more information, please contact:

EDITORIAL CONTACT:

Warren Osak
sales@electromate.com
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699
www.electromate.com

 

Tags:  Electromate, Tolomatic, Linear Actuator, Electric Linear Actuator, Rodless Cylinder, Rod Style Cylinder

 

IP Ratings & the Manufacturing Environment: How to apply linear actuators for quality, safety and long service life

A New White Paper from Tolomatic.

IP Ratings & the Manufacturing Environment:   How to apply linear actuators for quality, safety and long service life.

Click on the link below to download this White Paper.

http://mail.tolomatic.com/archives/pdfs/9900-9207_00-IP-Environments.pdf

 

Tags:  IP Rating, Linear Actuator, Electric Linear Actuator, Linear Positioner, Rodless Cylinder, Rod Style Cylinder

New RCP4W-RA IP67 Water Proof Radial Cylinder from IAI

Introducing the IP67 Water-proof Radial Cylinder, the newest addition to the dust-proof/splash-proof ROBO Cylinder® RCP4W series — Built-in guide to achieve longer strokes while accommodating a radial load on the rod!

A 1 minute video illustrating the actuator can be viewed at-

More information on the RCP4W-RA IP67 actuators from Intelligent Actuator can be viewed at-

http://www.electromate.com/products/series.php?&series_id=105503

For more information, please contact:

EDITORIAL CONTACT:

Warren Osak
sales@electromate.com
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699
www.electromate.com

 

Tags:  Electromate, IAI, Intelligent Actuator, Robo Cylinder, Linear Actuator, Electric Linear Actuator, Rod Style Smart Actuator, IP67, dust-proof, splash-proof

 

 

Choosing the best linear actuator based on manufacturers’ specs

Source:  Tolomatic Blog.  Originally posted by Gary Rosengren on Tue, Apr 22, 2014 @ 08:39 AM

Motion system designers often need to evaluate competing components to select the best one for an application.  For linear actuators and other motion system components, the decision generally comes down to which product will provide the longest service life given the specifications of the project.

Manufacturers give you performance data which can serve as guidelines for component ball screw linear actuatorselection and use.  Keep in mind, though, this information is for the individual component only and may not relate directly to the configuration and conditions of your application.

When you’re comparing data from different manufacturers, be sure you’re comparing apples to apples.  For linear actuators you may need to normalize the data of all the rolling elements (such as the ball screw or roller screw) as well as the linear bearing components in the system to the same Basic Rating Life (L10)

Basic Rating Life

International standards define life for individual ball or roller screws as the number of revolutions the shaft makes in relation to the ball nut body before the first evidence of fatigue develops in the load bearing raceways of the screw shaft, nut body, balls or rollers. For linear ball bearing systems life is defined as the linear distance traveled by a system before the first evidence of fatigue develops in the linear bearing rails.

Basic rating life (L10) for ball or roller screws for an individual screw or group of apparently identical ball/roller screws operating under the same conditions is the life associated with a 90% probability of achieving the nominal life (1,000,000 revolutions.) For linear bearing systems, basic rating life (L10) is expressed in linear units (100,000 meters of travel).

The standardized life equation for ball/roller screws is:

L10 = (C/P)3 x 1,000,000, where

         L10 = basic rating life in revolutions

C = dynamic load rating

P = application load

The standardized life equation for linear bearing systems is:

L10 = (C/P)3 x 100,000, where

         L10 = basic rating life in meters of travel

C = dynamic load rating

P = application load

These equations show the fundamental relationship between load and life. When the load on any given load bearing component is reduced by half, the life is eight (8) times longer. Inversely, increasing the load by 50% reduces the expectation to about 30% of life.

A Real-Life Example

Consider this example of evaluating linear bearing capability. You need to determine which actuator is more robust and best suited for an application. Manufacturer “A” (in red on the chart) has a maximum load capacity of 3,080 N (692.4 lbs.) while manufacturer “B” (in blue) has a maximum capacity of 1,996 N (448.7 lbs.)

In this first chart (on right) it looks like “A” is the winner, doesn’t it?linear actuator specs

But consider this. Manufacturers specify the linear distance or number of revolutions to which their ratings apply. So load ratings are based on the rolling elements’ specified L10 travel distance.

In our example manufacturer “A” has a Basic Rating Life of 600 Km while manufacturer “B” has a Basic Rating Life of 5000 Km. When Basic Rating life is normalized to 600 Km, this linear actuator specssecond chart (on left) tells a different story. Because the product from manufacturer “B” is able to carry the load for a longer distance, manufacturer “B” wins.

Normalizing the manufacturers’ data is a critical step in comparing performance data. It can lead to important discoveries.

 

 

 

 

For more information, please contact:

EDITORIAL CONTACT:

Warren Osak
sales@electromate.com
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699
www.electromate.com

Tags:  Linear Actuator, Electric Linear Actuator, Tolomatic, Electric Cylinder, Electromate


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