


SKF
We offer all the main types, including grid, gear, flex and jaw couplings. In addition we supply OK couplings, which use oil injection for mounting and dismounting, and flexible shaft couplings.
Flexible shaft couplings compensate for four types of shaft misalignment: angular, offset, a combination of the two, and axial movement. Grid couplings are aimed at high output, high torque gear applications, while gear couplings are heavy duty products with large bore capacities.
Most products are made from cast iron, though some (such as chain couplings) use carbon steel. Surface treatment techniques, including phosphate coating, help to protect against corrosion.
Our whole range of couplings can be searched and specified by clicking the ‘Online Catalogue’ button and choosing a product from the drop-down menu.
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.
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.
When using the OK couplings for shaft connections, advantage is taken of the powerful oil injection method.
Preparation of the shaft is simple. No keyways to machine, no taper and no thrust ring. When mounting the OK coupling, a thin inner sleeve with a tapered outer diameter slides onto the shaft. A thick outer sleeve with a matching tapered inner surface fits onto the inner sleeve. Ordinary mineral oil is then injected between the sleeves. A built-in hydraulic jack drives the outer sleeve up the taper of the inner sleeve.
When the outer sleeve has reached its final position an interference fit is created – just as if the outer sleeve had been heated and shrunk on. But no heat is required, and the coupling can be removed as easily as it was mounted.
This powerful use of friction enables the OK coupling to transmit torque and axial loads over the entire area of the shaft. There are no stress raisers at the keyway. And no fretting when high shock or reversing loads exist.
Very large couplings, which previously could only be shrunk on after heating, can now be assembled cold with the OK method.