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hydraulic flange puller

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  • hydraulic flange puller

    Has anyone ever seen drawings for a hydraulic flange puller. I want to remove large couplings on 2" to 4" shafts. I would love to see details or even photos of a press that would operate by fastening to the shaft (sometimes 20' long) and pull or push the fittings off. Gear pullers just don't do it. 20 to 50 tons of pull or push is what I need. I've broken to many gear type pullers and in this size it becomes expensive. Any ideas?????

  • #2
    We used to torch thru the coupling into the key to break them loose.

    A couple of heavy adapter rings, studs, and a porta power may do what you want.

    The old rail road wheel press had a thick C shaped ring to put over the coupling, and around the shaft while the ram did its thing.


    mite

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    • #3
      What is your application? Is the shaft straight or tapered and does it have a key? Most of the larger coupling have a shrink fit. You will have to heat them to get the off if they are a straight shaft. On some of the tapered fits there is a place to for a grease fitting. Pumping grease into the fitting will cause the ID of the coupling to expand which will reduce the force required to remove the coupling. There are straight and tapered keys. If you have a tapered key it will have to be removed first, then the coupling can be removed easily.

      Look at the Enerpac line of pullers and call you local rep. He should be able to help you with a puller to do you job. They are not cheap but will do the job for you.

      We had some very large pullers in the rolling mill for removing the large couplings from shafts. Some of our shafts were over 12" in diameter. We would use induction heaters and the pullers to remove them.

      Hope this helps.

      Joe

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      • #4
        A cheap import 20 ton portapower is a good place to start. 50 tons? Now you're getting up to major equipment like Enerpak. If you want to make you own go ahead. There's hardly anything simpler than a hydraulic cylinder. Start by finding the seals you need at a local hydraulics hose and service shop. You can buy kits. Find one and look it over. In fact rent a 50 ton puller kit and study it. It might be the cheapest $80 you ever spent.

        I seldom ever used fancy pullers on shaft coupling and gearing under 3". Mechanical puller and heat was far more portable and less trouble.

        The first place to start in removing tight couplings is to find all the pins, setscrews, keys etc and remove them.

        Next apply your favorite penetrating oil. Scientific tapping with a brass hammer having about 1/4 the weight of the coupling can sometimes work miracles. Tap around the diameter, tap axially, tap over the key, stop and squirt oil down setscrew holes. All this tapping has, I think, the effect of releasing adherent rust, encouraging the penetrating to do its job, and it gives you something to do while the oil is penetrating.

        If you decide to heat 2" and 4" shaft couplings to get them off don't mickey mouse around.

        Assemble everything you need and have a helper or two handy. This includes sone sheet metal scraps for heat shielding the end of the motor end bell or the gear reducer end a charged garden hose with a hand grip nozzle. If your helpers are inexperienced rehearse the moves so they know what you want them to do.

        Practice fire safety.

        You have to get a large input of concentrated heat into the metal along the line of the key to expand the coupling before the heat penetrates and starts expanding the shaft. Simply warming the coupling by passing a cutting torch around the coupling has little effect. The coupling has to be made suddenly hotter (thus larger) than the shaft.

        Use a big rosebud tip and all the fuel/gas you can safely put to the torch. Two torches are even better on a larger coupling or gear or whatever.

        I like to set up the puller and apply tension before heating. Arrange the puller jaws at points to avound heating them. If the coupling in keyed start, heating there. If the coupling is flanged, heat a spot on both sides of the flange over the key. If need be, use a small stream of water to extract conducted heat from the end of the shaft.

        If all goes well the coupling will let go with a thud. Follow up quickly with the puller to keep the removal going. Fast coordinated work means the difference between 5 minutes and 5 hours in removing a coupling.

        If the coupling come half off and stops don't try to force it. Chances are conducted heat has peneterated to the shaft and expander to take up the chearance you gained from the initial heating. Stop, apply a little water to the shaft to prevent heat from soaking down to the bearings, seals, whatever. Allow things to cool naturaly over night and start again in the morning.

        If you do it right the coupling, key, and shaft will not be harmed except for a little scorching.

        You may hit hard luck. Sometimes the coupling will gall on the shaft. If it comes off, fine. If it doesn't you may need to sacrifice the coupling by splitting it off the shaft. This is to be avoided if at all possible for couplings are expensive and to replace them may cause unacceptable delays. Still its a possible development.

        Splitting off a coupling is no big deal. A sawzall is a hell of a tool for this job and the surgical risk of using it is much lower than a cutting torch or a carbon arc. Mark the shaft of an expensive motor or reducer and the customer won't be happy.

        [This message has been edited by Forrest Addy (edited 05-10-2004).]

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        • #5
          Most Cat dealers will rent large portapowers ( enerpac type)from their tool room. For once in a while type use its a cheap way to go.
          Jim

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          • #6
            These couplings are on propeller shafts from what we call draggers. The shafts have couplings to join intermediat shafts and also steady bearings. They should be pulled cold. There are keys and set screws. There are also keeper bolts which pass beside the shaft on either side. The shaft is inletted half the diameter of the keeper bolt (about 3/8ths inch) . We do remove the keepers and usualy the set screw. The rest is pulled. It takes on average 50 tons to do this. Usualy we are pressing out the stub to salvage the fitting after we cut them. It would be good if I could salvage the entire shaft. There are no tapers on this type of fitting either. Heat is an option but not a good one. Power would be the best. When they are installed they are a push fit. The fastening hardware is then installed. It is hard to believe but after just a couple of years in salt water they do seeze on to the point that 25 tons on a 3" shaft will not even come close to moving them. I would like to construct a puller were I could get down in the hold of the boat and mount it to do the job. I would say in most cases I have an area around the shaft of about 20" diameter by about 3' long to get my unit in place. As far as rental goes, well this is seal and polar bear country. Rental shops Ha!

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            • #7
              Well I can tell you that if you need to build a big porta-power cylinder look in McMaster-Carr,on the same list as the complete cylinder they list the repair kits for them,what I do it buy the kit for the tonnage I want and build to the kit,works good.
              I just need one more tool,just one!

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