Top Menu

Helical Products Company, Inc.

Flexure Matters

The inspiration for the Helical Flexure came form the observation that one piece “flexured” flexible couplings offered maximum versatility  in terms of form, function and reliability.  Over time, the adaptability of the Heli-cal Flexure in couplings, u-joints and precision machined springs has helped to solve thousands of mechanical misalignment problems.  The flexing qualities of the “flexure” can be customized to compensate for angular and skewed misalignment, parallel offset and axial motion.  All of this can be accomplished while maintaining constant velocity rotation and smooth bearing loads.

 

Heli-cal Flexures can be designed to customer specifications by simply changing coil dimensions and/or materials.  Each of the following flexures are made from the same material, and have the same outside diameter and length.  These groups of matching colored flexures demonstrate how varying a single characteristic can influence performance.

“Flexure” concept promotes application versatility.

All other things remaining equal, as coil thickness increases, so does torsional stiff and torque load rating.

All other things remaining equal, as coil thickness increases, so does torsional stiff and torque load rating.

 

 

The four red flexures below are identical in outside diameter (OD), inside diameter (ID), length and number of coils.  The only difference is the coil thickness.  Changing this feature affects torque, angularity (bending moment), parallel misalignment (radial load), torsional rate and compressions spring rate.

 

As ID increases in otherwise identical flexure, torsional flexibility increases and torque load rating decreases.

As ID increases in otherwise identical flexure, torsional flexibility increases and torque load rating decreases.

All of the green colored flexures are identical with the exception of the inside diameters (ID).  This change affects the torque, bending moment, radial load, torsional rate and compression spring rate.

 

The only difference between each of the blue colored Heli-cal Flexures is the length of the coil.  Changes in flexure length affect angularity, radial load, torsional rate and compression spring rate.  However, torque capacity remains constant.

With varying coil length, torque capability remains constant while other performances properties change.

With varying coil length, torque capability remains constant while other performances properties change.

The gold Heli-cal Flexures are multi-beam designs.  Multi-beam flexures have two or more coaxial beams.  The difference between a single beam and multi-beam flexure is analogous to the difference between a single and multi-lead screw.  The affect of changing the number of flexure beams, with all other factors remaining constant, will result in changes to all five performance criteria.

Variations in the previously mentioned characteristics affect the performance of the flexure in dramatically different ways.  Altering these factors results in performance changes that may be linear, by the square, or by the cube.

 

Changing the number of beams significantly changes all performance characteristics.

Changing the number of beams significantly changes all performance characteristics.

Helical engineers manipulate the various attributes of the flexure to create products that meet the performance criteria specified by the customer.  To this point, we have only discussed what can be done by changing the flexure geometry.  This is only the beginning.  When you consider the additional utility that can be achieved by varying the material from which the flexure is made, or integrating custom end attachments into the product design, you realize there is more to this Heli-cal Flexure concept than originally thought.

 

With all of this versatility, the only missing ingredient is the imagination of the design engineer.  The Heli-cal Flexure is definitely more than a means to connect two shafts; it’s a mechanical solution!

Comments are closed.

© 2017 Helical Products Co.. All Rights Reserved.