Rotating conical clamping sleeves

In the case of chucked turned parts which are manufactured from pre-sawn rods, the problem continuously crops up of the rod ends being uncontrolled in the spindle tube. This steers them away from the central axis and they thus become increasingly out of balance as the speed increases.

This causes strong vibrations which can produce an effect reaching as far as the front and onto the turned part for manufacture. The result is dimensional inaccuracies and non-circular finished parts. It can go as far as loosening the clamps for the parts. Moreover, the raw material running out of balance obviously damages the machine from its bearings to its foundation

The whole problem is generally solved by a spacer placed at the end of the spindle tube. This only functions, however, if you have suitable bushes for the material diameters. Whereas it is still possible with shiny material, there are already certain problems with black material because of the high diameter tolerances and with section bars the solution becomes difficult to achieve. The greatest difficulties arise, however, irrespective of what material is used, as soon as the raw material becomes shorter than the spindle tube. That is because the spacers, with which you were previously familiar, do not rotate safely in the spindle tube.

All these problems can be solved by the new type of rotating clamping sleeves. These clamping sleeves consist of three parts - the clamping nut, the cone and the conical inserts. By turning the clamping nut, the internal diameter of the conical inserts is altered. The alteration of the diameter amounts to several millimetres. Differences in the material’s diameter can thus be compensated. By turning the clamping nut, the surface of the material is also firmly clamped.

This results in the entire clamping sleeve being pulled along when the raw material is pulled forward and prevents the material from slipping out. As a result of the conical inserts being centrally clamped, the machine runs without vibrating. This makes higher cutting speeds possible and produces longer tool life cycles. Part accuracy is also increased, as no deflections of the raw material inside the spindle tube can have an effect on the finished part. The rotating clamping sleeve is available in all common spindle tube diameters. The conical inserts are available in round, rectangular and hexagonal versions. Customised cross-sections can also be manufactured.