Flexi Couplings

Flexible couplings with oil injection mounting.
SKF oil injection method applied to flexible shaft couplings.
By combining the principle of SKF oil injection method on flexible shaft couplings, a high torque interference fit for plain, cylindrical shafts is obtained. Since there is no need for machining any keyways, splines or tapered shafts, smaller shaft diameters can be used, thus less weight. Mounting and dismounting are fast and easy with no external tools except a pump set.

Principle
The coupling works on the same principle as the SKF OK couplings, i.e. a thicker outer sleeve (in this case the flex coupling hub) with an internal taper is driven up on a thin, externally tapered inner sleeve. Oil is then injected between the sleeves in order to virtually eliminate friction between the tapered surfaces. For more information, refer to the section OK couplings.
The couplings then have an inbuilt hydraulic unit which creates an oil pressure thus driving up the flex hub on the inner sleeve.