Our customer manufacturers corrugated boxes. One of their roll drives involved a universal-joint assembly to accommodate a rather severe angle (20°). Unfortunately, the shaft failed on a regular basis. They needed to eliminate this costly maintenance headache.
We reviewed the application. The angle and envelope were both challenging. The distance between shaft ends limited our options.
After reviewing several approaches, we came up with two options. The first was another cardan style assembly that would drop into the existing connections, yet offer increased capacity. The alternate design would use constant velocity components. This assembly would require end fitting changes and the overall cost would be greater. However, it would insure even longer life.
Considering the costs involved, the best solution was to try and monitor the performance of the cardan design.