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Proper insertion of sintered bronze bearings — Parallax Forums

Proper insertion of sintered bronze bearings

idbruceidbruce Posts: 6,197
edited 2012-07-29 11:49 in Robotics
Hello Everyone

For several years now I have been messing around with sintered bronze bearings, but I never learned the proper procedure for installing them. During my afternoon research, I came across an article which describes the proper procedure and I thought I would share the information. Most of you probably don't need the information, but for those folks that use sintered bronze bearings, it is nice information to have.

http://copper-casting-alloys.brass-copper-fittings.com/oil_impregnated_bronze_bearings.htm

Bruce
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Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-12-31 11:26
    'Interesting info, indeed. It explains why my past attempts to press such bearings into a hole without using a pilot resulted in a too-small ID that seized the shaft.

    -Phil
  • PublisonPublison Posts: 12,366
    edited 2011-12-31 12:55
    OK. I didn't say this, but this is what erco would have said.

    "Wait a minute! You taught Phil something!" :)
  • idbruceidbruce Posts: 6,197
    edited 2011-12-31 14:13
    Okay let's set the record straight.... With this post, I did not teach anyone anything. All I did was share some information that I found online. And if I had my way, I wish someone would have taught me this technique years ago, before experiencing similar grief, like the grief Phil had mentioned. I have not even tried this method yet, but it sure sounds good.

    Bruce
  • PublisonPublison Posts: 12,366
    edited 2011-12-31 15:50
    idbruce wrote: »
    Okay let's set the record straight.... With this post, I did not teach anyone anything. All I did was share some information that I found online. And if I had my way, I wish someone would have taught me this technique years ago, before experiencing similar grief, like the grief Phil had mentioned. I have not even tried this method yet, but it sure sounds good.

    Bruce

    Bruce,

    I guess what I meant to say is that was a great link! Thanks for sharing!

    Jim
  • Tom CTom C Posts: 461
    edited 2011-12-31 17:57
    Moral of this story: Only use sintered bronze bearings in wood (hear that erco, wood!) or other non-metallic material like I have done. Never tried to use them in a metal chasis.
    Regards,
    TCIII
  • idbruceidbruce Posts: 6,197
    edited 2011-12-31 18:08
    Your welcome Jim. I enjoy passing good links onto others :)
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 02:40
    For those of you that like to keep PDF files of handy information (like I do), here is another link to the same info in PDF format.

    http://www.symmco.com/pdf/pilot-drvr.pdf
  • TtailspinTtailspin Posts: 1,326
    edited 2012-01-01 07:35
    I was lucky I guess, I was taught the only way to install bronze bearings is by using a pilot and press.
    Oh, and put the bearings into a freezer for 10 minutes or so before you quickly press them into place...


    -Tommy
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 09:42
    Okay I'll bite.

    Why put them into the freezer for ten minutes before pressing them in?

    Bruce
  • LeonLeon Posts: 7,620
    edited 2012-01-01 10:01
    It shrinks it slightly.

    I vaguely remember reaming that type of bearing to size after pressing it into position, when I replaced one on a motorbike I had nearly 50 years ago.
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 10:02
    Yeah, that is what I have done in the past, but it clogs the pores, and thus provides improper lubrication.
  • Tom CTom C Posts: 461
    edited 2012-01-01 10:03
    idbruce wrote: »
    Okay I'll bite.

    Why put them into the freezer for ten minutes before pressing them in?

    Bruce
    For the same reason when installing the starter steel ring gear on the aluminum clutch flywheel you put the ring gear in the oven to expand it and the clutch flywheel in freezer to shrink it. Makes it much easier to get the ring gear on the clutch flywheel.
    Just a thought.
    Regards,
    TCIII
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-01-01 10:37
    Regarding the heating and cooling: It seems like you'd have to work very fast and very accurately. Heaven help you if the parts regain their natural size before the pressing-in is complete or if something goes together askew.

    -Phil
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 10:53
    One thing is for sure, you certainly don't want to heat anything, because your oil will drain out of the bearing.
  • TtailspinTtailspin Posts: 1,326
    edited 2012-01-01 10:54
    Yes, very quick, and very accurate...

    Everything should be ready, the press should be at the right height, the die should be in place,
    In fact, its a good idea to practice the whole operation while you wait for the bearings to chill.
    When you are ready to go, just stab the pilot into the bearing, place pilot tip into the race, and start pumping... :smile:


    -Tommy
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 11:00
    I must say that I did not think this thread would get this much attention, but I am glad that it is, because I am tired of inserting these bearings improperly.

    Bruce
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 11:04
    Has anyone seen or used a pilot set for installing standard size bearings?
  • PublisonPublison Posts: 12,366
    edited 2012-01-01 11:06
    Tom C wrote: »
    For the same reason when installing the starter steel ring gear on the aluminum clutch flywheel you put the ring gear in the oven to expand it and the clutch flywheel in freezer to shrink it. Makes it much easier to get the ring gear on the clutch flywheel.
    Just a thought.
    Regards,
    TCIII

    Same principle as replacing wrist pins in pistons.

    Heat piston, freeze wrist pin. It put a lot less pressure on the components like a hydraulic press would.
  • idbruceidbruce Posts: 6,197
    edited 2012-01-01 11:09
    Publison
    Heat piston, freeze wrist pin. It put a lot less pressure on the components like a hydraulic press would.

    Yea, I don't know what I was thinking. After the first response, I said "A DUH" :)
  • TtailspinTtailspin Posts: 1,326
    edited 2012-01-01 11:45
    Has anyone seen or used a pilot set for installing standard size bearings?
    I've just used a piece of the axle stock, champher the end a tiny bit,(both ends if you use a hammer instead of a press.):smile:
    Dip it in oil too, and hope that makes up the .003... :)

    If you like calculators, check this out..


    -Tommy
  • $WMc%$WMc% Posts: 1,884
    edited 2012-01-01 18:29
    The problem usually starts with the hole the bearing is pressed into----Too small.
    '
    This hole should be drilled undersized then reamed to the final size.
    '
    The proper size for the bearing is giving by the manufacture in most cases.
    '
    I wouldn't use any heat, But freezing the bearing will make it a little easer to install.
    '
    You can buy adjustable reamers if your using inexpensive/lower quality bearings that very in O.D.(Like I do for low duty-cycle projects.)
    '
    If your installing the bearings in some hard material, I would use a hone to get the finished hole size (major bearing journal Dia.)
    (Adjustable reamers tend to chatter on hard stuff,The hone doesn't)
    '
    If you get the O.D. rite the press-fit will be rite and the I.D. will be rite.
    '
    No drag---
    '
    Making the journals parallel and on center is a whole new story.:smile:
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-01-01 18:56
    Despite the other issues I had when assembling my MakerBot over the summer, I was quite impressed with the efficacy of the self-centering bronze bushings they supplied with the kit. They were easy to install, and I never had a problem with them binding -- even on two parallel shafts, which is pretty remarkable.

    -Phil
  • idbruceidbruce Posts: 6,197
    edited 2012-01-07 05:16
    For those that are interested, I just tried the pilot method to install a new bearing, and I must say that I am more pleased with this bearing installation than any other sintered bronze bearing that I have installed. With a proper size housing bore and a proper size pilot, the bearing went in with no problem (nice snug fit) and the pilot was easily removed. And last but not least, the shaft spins freely :)

    Success!

    Bruce

    EDIT: And as an added bonus, I now have a pilot for a bearing size that I use fairly regularly.
  • KievlaninKievlanin Posts: 55
    edited 2012-01-17 16:56
    For all,
    To install round sleeve bearings (brass, sintered, plastic, aluminum):

    First, use measuring tools!
    Check dimensions of the hole and bushing before installing!
    Second use "machinary handbook" or ask me if you wish. To find out what dimensions should be.
    Depending on ratio: hole ID/bushing OD you will need to use nitrogen, freezer, press or just hummer.
    It is always nice to have any sort of "piloting".

    I am making/ installing/designing bushings of all kind every day.


    Send me your questions.
    I will be glad to help you!


    Mechanical Engineer
  • idbruceidbruce Posts: 6,197
    edited 2012-07-03 02:38
    To Those That May Be Interested

    I just thought of something. Installing sintered bronze bearings without an adjustable reamer can be an arduous task, because these bearings require an undersize hole and the drill bits that are readily available will not create the proper size hole. If you are installing sleeve bearings in aluminum, you should be able to modify a drill as I have outlined in this thread, to give you the proper size diameter hole: http://forums.parallax.com/showthread.php?140164-How-To-Make-Shaft-Couplings-Backyard-Style This may also work with steel, although I have not tested it at this point.

    Bruce
  • LeonLeon Posts: 7,620
    edited 2012-07-03 02:43
    A reamer is the usual way to finish a hole to the correct diameter.
  • idbruceidbruce Posts: 6,197
    edited 2012-07-03 03:23
    Installing sintered bronze bearings without an adjustable reamer can be an arduous task
    A reamer is the usual way to get finish a hole to the correct diameter.

    Reamers are very expensive, especially for the hobbyist just needing several sleeve bearings. For a single reamer, you better be able to invest $30+ as compared to a $3+ for a drill bit.
  • $WMc%$WMc% Posts: 1,884
    edited 2012-07-04 10:25
    Hello Bruce--
    ''
    Bearings' run in the .0001" range.You wont hand grind a drill that will fit this bill.
    '
    Think like a Machnist....Not an Electrician....
  • idbruceidbruce Posts: 6,197
    edited 2012-07-04 10:45
    Walt

    You must not have investigated the link in the first post :) 0.0001"?
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-07-04 10:52
    Bruce,

    Even an accurately-ground drill bit is no substitute for a reamer. The two operate in entirely different modes. A drill bit cuts only on the end -- not on the sides. Once the initial hole size is established by the end cut -- which, by its nature will be too imprecise for close-tolerance work -- no further cutting takes place. A reamer, by contrast, cuts on it sides, which sides can be precision-ground to the correct diameter. For precision work, a drilled hole can never be more than a pilot for a good reamer. Just spend the money. You won't regret it.

    -Phil
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