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DIY bearings in 5hp motor idler RPC

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  • #16
    the bolts that connect the end bells usually go through holes in the stator, if you don't mark the housing it can be a pain in the butt to line up the bolts. Did you take the 10-32 screws loose that hold the bearing retainer plate on the drive end? Usually you don't have to, but sometimes it makes it easier to tap out the shaft and rotor. Jim

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    • #17
      Originally posted by Rich Carlstedt View Post


      I take it that you and Doozer have not rebuilt many motors with that comment ?

      First, not all motors have a spigot /groove on the bells
      Second , to make sure Lube points/cups match original orientation !
      Third , its possible the bells to be rotated counter to each other and still allow the long bolt to be tightened, yet the orientation can move and they can loosen ( Vibration source)

      Rich
      A fair number. Any decently made motor made with the intent to be repairable has spigot or other alignment means. I have not yet run into an industrial type motor that lacks that.

      Cheapo motors ? washing machine motors? something from Alibaba? You are on your own for those.

      Grease zerks? Often the REASON you want to rotate the end bells, since the mount means is often/usually on the body, and may not be horizontal in the place you want to put it..
      1601

      Keep eye on ball.
      Hashim Khan

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      • #18
        This motor has grease zerks, but they seem to go nowhere, the bearings are sealed. I made a Ruby Goldberg bearing 'un-presser' to get the end bell off. No big deal, it came apart with little more than hand pressure.I can see the bearings are sealed, and that makes no sense as to the zerks. Also, this shows signs of being partially submerged in water,.
        So, I cleaned it all up, and the bearings feel good after cleaning all up.
        The bearings are definitely pressed onto the armature shaft, but the end bells come off rather easily.

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        • #19
          Originally posted by Ringo View Post
          This motor has grease zerks, but they seem to go nowhere, the bearings are sealed.
          Huh, thats weird. I wonder if they've already been replaced once? As long as they feel OK I guess it doesn't matter.

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          • #20
            Originally posted by Doozer View Post

            Why ? ? ?
            I have re-clocked motor end bells a few times,
            to change mounting orientation or pecker head location.
            If parts like this don't have related features on a common centerline,
            they would never pass QC when manufactured.
            I think you are propagating an old wives tale that was never true
            in the first place.

            --Doozer
            Old Wives Tales are prevalent in home shop work, do not crush their beliefs, nothing good comes from this.

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            • #21
              Beliefs are the hardest thing to change.

              -D
              DZER

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              • #22
                Ja, that's just weird. At work we had a licensed electrician (pretty much required by law, and the insurance companies ) and he had no problem with rotating the end bells whatever way he needed to make it fit into whatever machine it was going in. Guys about to retire at any moment, so its not like he's inexperienced. Any questions about greasing it or changing brgs etc referred to him.

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                • #23
                  Put it back together and the bearings sound noisy.
                  I guess the end bells amplify the noise like a drum head.

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                  • #24
                    Originally posted by Ringo View Post
                    Put it back together and the bearings sound noisy.
                    I guess the end bells amplify the noise like a drum head.
                    Sure those bearings are OK? (yeah some end bells make it sound worse if they're real thin)

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                    • #25
                      Could it possibly be current leakage from the stator through the bearings? Also check for foreign material or signs of rubbing between armature and stator laminations.
                      http://pauleschoen.com/pix/PM08_P76_P54.png
                      Paul , P S Technology, Inc. and MrTibbs
                      USA Maryland 21030

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                      • #26
                        Jerry, Thank You for making my point !
                        Originally posted by J Tiers View Post
                        .................. Any decently made motor made with the intent to be repairable has spigot or other alignment means .....................
                        If orientation was not very important, they would not bother. They do that for peak performance and to make it "idiot proof"
                        Older motors, particularly Induction and DC motors can be greatly affected by slap hazard rebuilds
                        Rich
                        Green Bay, WI

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                        • #27
                          Rich, it seems you are approaching this motor bell orientation from a user/consumer level,
                          putting great trust in the manufacturer..
                          I am approaching it from an experience and engineering level. I have modified many
                          motors to fit applications that are rather custom, I know motors from a mechanical and
                          electrical point of view thoroughly. I believe I know what works and what does not.
                          You are approaching this on the side of caution. You are asserting your caution as wisdom.
                          The two are not the same. I am asserting my experience and engineering background as
                          wisdom, which might be a little more inline with the definition. So do what makes you happy
                          in your shop and we will continue to do the same.

                          --D
                          DZER

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                          • #28
                            After having this apart already, I can see 2 things here, quite obvious, even to an untrained eye.
                            1. the bearings are sealed and the grease zerks serve no real purpose
                            2. the end bells have only one purpose and that is to support the bearings, they are just plain round otherwise, there is no defined clocking position to them except for the long bolts
                            Keep in mind this is to be an idler motor for my DIY RPC, clocking isn't gonna matter, as long as it runs.
                            I'm enough of a mechanic to look for the simple stuff like armature rubbing on the field

                            Comment


                            • #29
                              Originally posted by Rich Carlstedt View Post
                              Jerry, Thank You for making my point !

                              If orientation was not very important, they would not bother. They do that for peak performance and to make it "idiot proof"
                              Older motors, particularly Induction and DC motors can be greatly affected by slap hazard rebuilds
                              Rich
                              Say WHAT?

                              There is a VAST difference between a spigot mount that allows rotation but keeps axial alignment, and a sloppy consumer grade fan motor with at best a peg for approximate alignment. And between a "slapdash" and a competently done rebuild.

                              NOPE, you get NO support from what I said. Sorry to bust the pretty bubble.

                              The stator can fit at any angle vs the end bells where you can put the screws through. If there is a required orientation, there will be pegs to prevent misalignment. You also see pegs or cast lugs and matching slots in cases where the motor is made for a particular application and is assembled by folks who don't maybe know what a motor even does.

                              Unless there are orientation lugs, pegs, dowels, etc, it's likely fair game.

                              Now, SOME motors DO have issues.

                              You mentioned DC motors. With a DC motor the end bell may make no difference, BUT the location of the brushes DOES. So, if you need to change the end bell orientation, you have to be able to change the brush mount to compensate and bring the brushes back to the same relative position. With many motors that is not possible, so with those you cannot move the end bell.

                              If the motor is one that has brushes, BUT the contact to the rotor is with SLIP RINGS, then the orientation is not an issue if the wires will reach without a problem. if the motor has a "commutator", with "segments" then it IS an issue.

                              An ordinary 3 phase "induction motor" has no difference in performance at ANY angle of end bell to the frame, So unless there is a mechanical orientation lug, etc, you are entitled to move the end bells. Maybe even if there IS a lug, if that is present only to assist in consistent assembly.

                              A single phase motor usually has the centrifugal switch on the end bell. That makes the wire length an issue, you have to have enough to keep the wires out of the way of rotating parts.

                              Some motors that cannot be re-oriented have a separate "bearing box" that is bolted onto the end bell. If you need to put an oil hole or zerk at a different angle, then you can usually just rotate the "bearing box" and replace the fasteners.

                              One does need to use some decent good sense to judge whether a particular motor is going to be a problem. But the motor manufacturers generally have made their designs fairly idiot proof (they know their workers) and a motor that has to be assembled one way and one way only, will generally have a means to prevent wrong assembly.

                              Most motors "we" will run across are fractional HP or low integral HP types, and most have 4 bolts that allow only 4 possible orientations.
                              1601

                              Keep eye on ball.
                              Hashim Khan

                              Comment


                              • #30
                                Motors usually have clearance through the winding for the bolts and only let the bolts pass at specific places, so marking the end bells can save time and ease reassembly. We would replace the bearings in motors any time we had them off the machine if had been awhile or if they sounded or felt dry or worn. The majority of the time the replacement bearings were sealed or shielded.

                                Jon
                                SW Mi

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