R&D Flexible Shaft Couplings Gets Rid of Vibrations

Published: 01/24/13 at 12:37pm

Are you tired of excessive vibrations coming from you drivetrain? One solution to help reduce drivetrain vibrations is a R&D flexible coupling. The flexible coupling is made of a polyurethane element that reduces vibration by flexing instead of compressing. Staggered bolts enable the polyester elastomer to isolate vibrations and compensate for some misalignment. The flexible coupling fits in between the shaft coupling and transmission flange. There are a set of bolts and straps that bolt both to the shaft coupling and transmission flange. This creates a failsafe design keeping the drivetrain together if you were to hit something strong enough to break the coupling. This would also save your transmission saving you costly repairs. The couplings are easy to install and can be aligned when installed. There is a wide range of flexible couplings fitting horsepower applications between 5 to 1500.

Flexible Shaft Coupling

Fail Safe

There are two steel straps that prevent the drivetrain from separating in the event you hit something strong enough to break the coupling. The aft steel strap is bolted to the transmission coupling and the forward steel strap is bolted to the shaft coupling. The aft strap will engage the forward strap and keep the drivetrain together if the elastomer is damaged.

Quick and Easy Installation

The couplings require no machining and come supplied with bolts to connect between the two existing shaft flanges. Checking the alignment on installation and during service checks is very quick and easy. You can check this by using the red bolt as a reference and checking the gap while manually rotating the shaft.

How to Pick and Choose the Right Coupling

Several bits of information are required to calculate the power of the coupling required. First the engine horsepower and speed. Second the gearbox type and reduction ratio. Third the gearbox flange details. These details include the diameter of the flange and register, pitch circle diameter of fixing holes and the size and quantity of holes. Here’s a equation to calculate the power of the coupling required.


Lets say that this will be for a Borg Warner Velvet Drive 72C 2:1 Reduction. It has a 5” flange, a 2.5” diameter register. The Pitch circle diameter is 4.25”. The distance between the center of the hole at 12 o’clock position to the center of the hole at 6 o’clock is the pitch circle diameter. And there are 4 off holes that have a diameter of 0.437”. Based off of this information we look at the R&D selector guide and see that the coupling required is a 910-009 Borg Warner.

So there you have it, a basic rundown on how the R&D Flexible Shaft Couplings work and can benefit you. From its vibration reducing and fail safe design to its quick and easy installation and alignment these flexible shaft couplings will make your life a heck of a lot easier.

-Jason Abrahamsen