CUSTOM OR "MODIFIED" COUPLINGS

The versatility of the HELI-CAL Flexure is the "secret ingredient" in each of the following design engineering applications. You will see how the versatility of the HELI-CAL Flexure means unprecedented design opportunities for you. We invite you to peruse this sampling of case histories... and then imagine the HELI-CAL Flexure’s application possibilities for your most challenging designs.

...And there's more. Check out our in-depth Flexure Facts Directory - A compilation of Solved Application Stories chronicling different custom couplings, springs, and u-joints and the history behind them.

Now you can also design your own custom couplings from the web!

A. End Play Eliminated

Between taxiing and takeoff, an aircraft engine is subjected to a battery of forces - imposing continuous misalignment on the aircraft fuel pump drive. Helical’s challenge was to design a Flexure for the aircraft fuel pump drive that would eliminate axial end play - yet, when needed, still allow absolute tooth engagement between pinion and gear. The solution: a flexured area allowing the shaft to angularly deflect and keep pinion and gear in mesh. Please note the square shaft - another example of Helical’s flexibility in meeting the designer’s desires.

B. Zero Backlash

The probe on a computer measuring device could not tolerate backlash without jeopardizing the accuracy of its readings. In response, we designed this one-piece HELI-CAL Spring whose flange and unique end attachment were integrated to eliminate all backlash and overtravel. Without this innovation, any over travel of the probe would have destroyed the transducer.

C. Specialty Coupling

Sounds so simple. Designers needed to connect two shafts as they assembled two subassemblies- but had no way to tighten down a clamp or set a screw. Helical responded with a coupling specifically designed for this unique application. Before assembly, the coupling was bolted to a flywheel. Then, with its shaft extension and clevis end, this coupling found the Flexure enabled the two shafts to engage, yet accommodated misalignments at the mating surfaces.

D. - E. Close-Tolerance Precision

In response to a growing number of requests, Helical has designed a series of close-tolerance precision couplings that are also adaptable to low inertia requirements. Series 3000 and 4000 are stainless steel; series 5000 and 6000 are aluminum alloy. Please note that the set screw unit (D) and the integral clamp unit (E) each offers standard shaft tolerances of .0005 in. Contact our engineering department for details. 

F. Spring Eliminated

An important safety feature in an assembly design appeared impractical because of the small quantities and high overhead involved in manufacturing a multi-coil, pre-loaded spring. The designer, unwilling to compromise on safety, contacted Helical. Because Helical requires no special tooling to produce this type of preloaded spring, we could provide working quantities that were substantially more cost effective than traditional wound approaches.

G. Flexible Configuration..Torsional Stiffness...Minimum Windup

When a design calls for either torsional stiffness or minimum windup, Helical can design a double- or triple-start precision spring. These springs are designed for long travel compression loads. Spring ends, which can be machined to any configuration, were squared to mate with the plate braced against them. Note: A DS prefix in a basic model number denotes a double start (two separate coils wrapped within each other); a TS prefix denotes a triple start.

H. Special Material

When miners needed a hand-held hammer drill to penetrate hard rock, the drill manufacturer turned to Helical for a wrapped spring clutch. With this HELI-CAL Flexure made from high carbon steel material (material that can’t be wrapped, only machined), the drill became a reality.