What are bellows couplings?

A bellows coupling is a type of coupling design which consists of a thin walled, flexible corrugation (bellows) that is connected between two clamping hubs.  They are traditionally used for servo motion control applications that have high positioning accuracy, speed, and torque requirements.

Cross Section View of Bellows Coupling

What makes bellows couplings unique?
Bellows couplings are unique because of the construction of the bellows which can flex and compensate for minor shaft misalignments (axial, lateral, radial), while still providing a zero backlash and torsionally rigid connection.  They are a unique blend of rigidity and flexibility.

How to specify bellows couplings
To specify a bellows coupling, the first parameters we typically look at are the torque and connecting shaft sizes which will help to give a general sense of the coupling size.  The nominal torque rating (continuous torque transmission)  of the coupling should be greater than the peak torque of the application to ensure a secure connection.  We then check the connecting shaft sizes which  must also be within the acceptable range of the coupling.  If the shaft diameter is smaller than the specified range on the coupling, the torque transmission value of the coupling can decrease.  From there, we check other application specific parameters which include the speed, shaft alignment, temperature, and drive resonance.  We need to make sure they are within the coupling specifications, if not, we look to apply a safety factor when applicable; otherwise we select a different coupling size, or design. 


Bellows couplings applications examples
When introduced, bellows couplings were first widely accepted in the Machine Tool industry for spindle drives.  Since then usage has expanded to a vast number of industries including Automotive, General Automation & Assembly, Material Handling, Medical, Packaging, Robotics, to name a few.


For more information about couplings, visit www.gamweb.com

GAM Product Range in Design World's August "Around the Web"

Did you get the August edition of Design World magazine?  GAM is on page 128 in the "Around the Web" section.  Use your smartphone and scan the QR code or click here for more information on our product range brochure.

What is an Elastomer Coupling?

Elastomer couplings can be plugged in, are backlash free, flexible shaft couplings for small to medium torques.  An elastomer coupling is typically a three piece design comprised of two hubs and an elastomeric spider.
The elastomer spider (insert) serves as the connection and compensation element with involute shaped teeth and high Shore hardness.  The spider is inserted with slight preload between two high precision machined hubs with matching involute shaped jaws.  The elastomer spider can compensate for shaft misalignments, is electrically insulating and demonstrates good oscillation dampening.

Areas of use for elastomer couplings range from general motion control applications to demanding drive systems in machine design including the spindle and axis drives of machine tools.  To learn more about elastomer couplings visit http://www.gamweb.com/elastomer-couplings.html

Infographic: What makes GAM couplings special?

Infographic: What makes GAM couplings special?

1.  A long history of coupling performance and quality.  Fact.  GAM introduced the bellows coupling to the North American Market.
2.  Easy Clamp System.  For easy coupling installation.
3.  Balanced hubs.  Balancing element allow for speeds up to 20,000 RPM.
4.  Brass Wire Press Fit Connection.  This bellows hub connection method was patented in 1974. 
5.  Specs you can believe in.  
6.  Huge coupling product range
7.  Customized for your application.  All of GAM couplings are custom machined per order.
8.  Deliveries you can count on.  98.1% of all couplings shipped on time or early since 2005.  Same day shipments are possible.
9.  Every coupling inspected.
10.  Excellent customer service and support.


For more information visit www.gamweb.com

Throwback Thursday
Back in 1991, GAM introduced the high precision bellows servo coupling to the North American machine builder market.  Here is the first coupling brochure that GAM ever printed:

(Front Cover)

(Inside Pages)

While a lot of things have changed since then...the core values of GAM have stayed the same:

• Dedication to customers
• Customizing product to fit the needs of our customers
• Technical Engineering Support
• Responsiveness
• Introducing high quality and new generation products
• State of the art manufacturing
• Long term relationships with customers

(Back Page)

One of the best parts of the brochure are the customer testimonials.  What's even better, is that they are still our customers today....over 21 years later.

Here are those testimonials:

"One of the attributes we look for in a supplier is 'responsiveness'.  I think the following story best shows GAM's concern for their customer's needs.  

'It was a Friday afternoon and our service engineer was at a customer's plant in Ashdown, Arkansas, servicing one of the packaging machines we manufacture.  He found he needed a coupling in order to get the equipment up and running by Monday morning.  He called GAM from his hotel room that afternoon.  On Saturday, he received the coupling at his hotel room, precision bored on both ends to his specifications, with keyways'

Our service engineer had the packaging machine ready to go by Monday and we had another satisfied customer."

Jeno Thuecks
Engineering Manager
Pemco, Inc.
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"As the largest manufacturer of double enveloping worm gears in the world, we must provide our customers with quality and high performance in order to maintain our leading position.  Whenever an application arises that requires zero backlash, high stiffness, and low inertia, we recommend GAM couplings.  These couplings exemplify the quality and high performance we demand.  Plus, their compact size easily fits inside our standard motor adapters."

Tom Scott
Senior Applications Engineer
Cone Drive Operations Inc.
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"As a retrofitter of CNC Screw Machines for the metal working industry, we understand that reducing downtime and minimizing machine damages caused by collisions are very important to our customers.  That is the reason why we turned to GAM for the excellent engineering assistance.  Because motor current relays react too slowly to protect our machines against damaging inertial forces, GAM helped us design a compact safety coupling which will disconnect the motor from the drive within 3-5 milliseconds.  Engineering safety is our highest priority in designing our machines and with GAM, we are meeting the concerns of our customers."

Martin Humphreys
President
Screw Machine Technology
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What a great brochure that really captures the essence of GAM...Take a look at our current literature