Custom Torque Limiters Minimize Wear and Backlash in MRI Machines

Sometimes, a standard torque limiter simply won’t cut it. At Mach III, our engineers can create modifications of our standard catalog models for many applications — including critical medical equipment. For example, in the following application, we customized our miniature torque limiters for magnetic resonance imaging (MRI) machines. Designed as a retrofit, these units overcame challenges related to wear and backlash during operation.

Aluminum Torque Limiters Create OEM Headaches

We designed and delivered these custom torque limiters for a major original equipment manufacturer (OEM) in the healthcare field. The application required components with nonmagnetic materials, a long wear life and reliable, backlash-free operation.

At the time, the OEM was using aluminum Polyclutch® torque limiters, which incorporated very thin drive discs and 0.02-inch sintered bronze friction discs that wore into the aluminum sleeve, leading to excessive backlash. The torque limiters’ aluminum hub also wore on the shaft it was mounted on, causing additional backlash.

Custom Torque Limiters Feature Backlash-Free Design

Mach III T2G24-002 Custom Torque LimiterOur engineers overcame these challenges with a custom torque limiter that minimized backlash and provided a longer wear life. Featuring fewer components than the Polyclutch® units, our torque limiters incorporated stainless steel components, which reduced wear compared to the aluminum components. The design also included a Shrink Disc to attach the coupling to the shaft, eliminating a wear-prone keyed connection.

And finally, our engineers machined a thicker drive and friction discs from bronze bar stock. Using our lobed drive geometry, we then connected the drive and friction discs to the drive hub and coupling, respectively. This geometry has a lower tolerance compared to the traditional lug-style drive and friction discs that were used in the Polyclutch® design.

Thanks to these modifications, our custom torque limiters successfully overcame the medical OEM’s wear and backlash challenges. Our engineers can also customize brakes and torque limiters to meet various application requirements for water resistance, food safety and many more.

To learn more please visit our custom products webpage.