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Trantorque – Elegantly Simple. And Awesome.

by Senior Applications Engineer Chris Ward

Chris Ward has been around the Trantorque Keyless Locking Device for a long time. It all began in the 1980s, when Ward, Fenner Drives’ Senior Applications Engineer, was working in England.

He had the opportunity to test an early version of the device and was impressed.

“It was so simple. It was so freaking cool.”

And now, 6.5 million units sold (and counting), the idea is still gaining popularity.

Almost Unequalled

As a single-nut, keyless locking device designed to connect a hub to a shaft (usually motor-driven), Trantorque is almost unequaled.

It installs easily, with just a torque wrench.

It performs better than alternatives, outlasting keyways cut into shafts, the prevailing industry standard, and it’s much easier than welding.

And it is incredibly versatile, handling torsional/axial/bending moments, speeds of 15,000 RPMs (working closely with our technical services group), temperatures up to 400°F, and an endless array of stops and starts. Is capable of multi installs and removals. And, with the right plating or base metal, it can handle corrosive atmospheres.

Its only limitation? It can’t go larger than three inches, because the amount of torque required to install it simply gets too large. At that point, multi-screw KLDs like Fenner Drives’ B-LOC , make a lot more sense.

Simple Engineering

To Chris’ original point, the engineering of Trantorque is incredibly simple. The device features two parallel (and opposing) tapers and a threaded, hex-nut exterior. Tightening the single nut increases the coefficient of friction on the inside taper, clamping down on the shaft. At the same time, the device expands into the hub, locking it in place.

And unlike multi-screw KLDs, the design is self-centering, and the tightening is uniform across the entire surface. The threads have been carefully engineered so that the device can handle industry-leading torque.

“When I tighten the nut, the threads pull around the entire 360 degrees.”

Thus Trantorque achieves a mechanical press fit that is self-centering, optimizing the mounted components radial and axial runout capabilities.

“You can’t get any better than that.”

Over the years, he’s had a lot of experience explaining the device to customers who are a little skeptical to start. Especially purchasing people who see keyways as a cheaper alternative.

Engineers Appreciate It

“Engineers can appreciate it. They get what they’re buying and why they’re paying a little more for it, especially when they consider speed of installation and the resulting savings. And it’s even worse when they consider the true cost of machining a keyway – increasing the shaft size, mistakes in making the cut and so on.”

Chris says he is still amazed at the number of engineers he finds who are not familiar with the device.

“I can still go to trade shows and meet engineers who never saw one before. And they’re experienced people that have been in the field for years.”

Their reaction is just the same as his was, almost four decades ago. They immediately see the dozens, if not hundreds, of potential applications.

“Once you explain it to them, they think it’s really cool. And then they’ll go, ‘We could use it for this. Or we could use it for that other thing. You can’t twist it. You can’t pull it. You can bend it. That is so cool. It’s awesome.’”


To find out more, visit our Trantorque Keyless Locking Device page. Or, for immediate assistance, call 1-800-243-3374 and ask to speak to customer service or an Application Engineer or complete the contact form.

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