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Heat => Puller
Elaborate on the pullers used!
The most common and most effective puller is usually a spacer ( e.g. large nut ) set between the shaft ends and then using longer bolts ( fine thread / grade 8) one puts a strain on the assembly. At some point there is a danger of warping one or both coupling flanges but in normal cases this is not a problem and such an approach is SOP. It is safest in an extreme case to make a plate of 1/2" to 3/4" steel with holes drilled to match the coupling to be removed and then do the spacer-long bolt trick. Heat generally must be applied HOT and QUICK so as to heat the coupling and not the shaft and thereby expand only the coupling. One can improve the effect by packing the shaft coupling in ice ( or ice&salt) to get as cold as possible before applying heat. Generally an oxy-acetylene torch is needed as a propane torch heats to slowly to confne the heating to the coupling. Be sure that there are no pins or set screws lurking under a coating of corrosion. It has happened to many that they swore and pounded and heated and pulled and pushed, only to find out that it was pinned or set screwed.
If the shaft must be saved and the coupling is GLUED on, one can cut the coupling down one or both sides as close to the shaft as possible and tap the thin layer of metal with a sharp cold chisel to expand it a bit or use a grinder to cut just through to the shaft and so loosen the coupling. No fun when staning on your head with near zero clearance on all sides but do-able in a pinch.
Last edited by sailandoar : 08-15-2006 at 02:11 PM.
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