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Gearbox Design

  1. Jun 14, 2009 #1
    For one of my classes, I have to design a gearbox. i am currently going through some calculations, but before I get too far in, I would like to know where one can find a list/catalog of readily available gear sizes/pitches.

    The gearbox clearly has to satisfy certain load carrying parameters, but it also has a size constraint, so I don't want to start with an 8" diameter pinion, if I can start with 2" (these are not actual numbers, just for example)

    I need a good resource for gears and i am sure that somebody here know a nice one :smile:

  2. jcsd
  3. Jun 14, 2009 #2


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    Last edited by a moderator: Apr 24, 2017
  4. Jun 14, 2009 #3
    That's great start for me nvn. Thank you.
  5. Jun 14, 2009 #4
    Bear in mind that gears can be cut to almost any spec. If this is simply a classroom design project that does not have to be built, you can specify anything that is buildable, whether you can buy it off the shelf or not. Gear cutting is available in almost every city in the US of any size at all, so don't be too concerned about this (one off may be more of a problem, however).
  6. Jun 14, 2009 #5
    Well, my professor has been very adamant that this is a concern. I realize things can be special ordered, but his point his why bother?

    So they do have to be off-the-shelf. Thank you though.
  7. Jun 14, 2009 #6


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    There is also


    Although, if you buy anything from them they will send you post card for the next decade.
  8. Jun 14, 2009 #7


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    And they don't even send Christmas ones or Easter ones. It's always the same card with a gear on it. booring... :(

    Hey Salad. Try also http://www.mcmaster.com/#gears/=2bfnsw".

    Oh, and Dr.D is right about just having one custom made - your prof's concern is overblown. They're not much more expensive if you're buying a dozen or so. Most of the cost for such things goes into set up charges, so once you buy one to pay for the set up charge, the rest are fairly inexpensive. I've spec'd out a half dozen different gears over the years and found very competitive pricing even for quantities as small as 5. The cost of 'off the shelf' has to be weighed against the fact that there's not a huge market for off the shelf gears so prices aren't that much less to simply have one made.
    Last edited by a moderator: Apr 24, 2017
  9. Jun 14, 2009 #8
    Last edited by a moderator: Apr 24, 2017
  10. Jun 14, 2009 #9
    The very best reference and source I have found is www.wmberg.com
  11. Jun 15, 2009 #10
    In the same point i design a gearbox but i didn't find formula for the distance between two gears on the same shaft
  12. Jun 15, 2009 #11
    Two gears on the same shaft are where ever you choose to locate them, provided they do not overlap. The point is they have to be aligned with the gears they will mate with; that is what determines the planes they must be placed in.
  13. Jun 15, 2009 #12
    Thanks Dr.D
    i got it
  14. Jun 16, 2009 #13
    Is there any program to calculate gearbox speeds, dimensions, gears and shafts dimentions and selecting bearing form input power ?
    i need the gearbox for centerlathe

    plz. is there a standard allowed deflection for shafts ?? i need a source
  15. Jun 16, 2009 #14


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    If there is, I wouldn't trust it. Some of us get paid to do this stuff for a living. All of the questions you asked require real engineering work to be performed. I would recommend calling the manufacturer of the lathe and see what they recommend. If that is not an option, try retrofitting an existing gearbox from a similarly powered lathe.
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