Our customer builds special gear boxes that are used for the textile industry. The process requires that each box is driven by a common shaft, and that these gear boxes be capable of being moved in-and-out along the length of the shaft.

Traditionally, this has been accomplished by using a long splined shaft. Unfortunately, the inherent misalignment and backlash of this approach has resulted in a high maintenance situation.


A review of the application pointed toward the use of a universal shaft—which offered high misalignment capability and axial slip. Unfortunately, this process required significantly more axial movement than commonly available.

It turned out that we were able to meet this need with a “tunnel-shaft” design. With this design, the long spline within the universal shaft was protected from the misalignment. The net result was an assembly that met the difficult operating parameters without the high maintenance and short life problems.

Let us know if you have an unusual coupling problem.