Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: Designing bevel gears

  1. #1

    Default Designing bevel gears

    I have a back burner burner project to which I think bevel gears might suit.
    Up to about 500 Watts needs to be transmitted at right angles with ~3:1 reduction, pinion ~2" dia and crown ~7" dia. Pinion rpm ~2100.
    The question is what materials will make reasonably quiet running gears with no or dry lubrication and decent life?
    Will a combination of some kind of plastic and metal work?
    I have a set of M1 cutters, will M1 gears of reasonable tooth width work?
    Just tell me if I am dreaming, I'm open to suggestions.
    John.

  2. #2
    Join Date
    Sep 2015
    Location
    NW Illinois
    Posts
    564

    Default

    You definitely want steel for the pinion. I am not sure how a plastic gear would perform. It is worth a try. I suspect canvas reinforced phenolic for the nonmetallic gear. If you haven't got Ivan Law's book on gears and gear cutting I suggest getting a copy. As far as strength design goes there are probably online calculators available. One way to lower the tooth loading is to increase the pitch diameter of the pinion and gear.

  3. #3
    Join Date
    Dec 2015
    Location
    Chilliwack, BC, Canada
    Posts
    3,989

    Default

    Given your desire for long life, quiet operation and little or no lubrication I'd say that the best way to design them involves ordering suitable parts from some drive line component maker like Small Parts. Making spur gears is one thing but making smooth running quiet bevel gears would be a whole other level. Tapered teeth and all that you know.... And 500 watts is 2/3 of a HP. So that's not light duty to my way of thinking.

    It would be overkill but if you're considering a 2" crown and 7" pinion then find a small rear axle from some sort of compact car and adapt them to your needs. They would require lube but they would be very quiet.

    But considering that gears that size easily handle many HP I'm thinking that you don't need anything that size.

  4. #4
    Join Date
    Aug 2018
    Posts
    22

    Default

    My first thought is one brass and one steel, involute.

    My second thought is to dismantle an angle grinder.

  5. #5
    Join Date
    May 2011
    Posts
    1,105

    Default

    What does Ivan say?

  6. #6
    Join Date
    Apr 2001
    Location
    Maine
    Posts
    7,009

    Default

    It's been a while since I read Ivan Law's book (Gears and Gear Cutting) but I do remember that he explains how to cut constant-depth bevel gears. They aren't the same tooth profile as commercial bevel gears, but they are a valid form that work. They can be cut using "normal" shop equipment; they don't require specialized gear-cutting machinery.
    If you want to try cutting bevel gears, I highly recommend that book.
    ----------
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.
    Don't own anything you have to feed or paint. - Hood River Blackie

  7. #7
    Join Date
    Dec 2007
    Location
    South Wales
    Posts
    6,602

    Default

    My first thought was worm and wheel to do the grunt then use further gears to get to where your going
    Mark

  8. #8
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    2,246

    Default

    Quote Originally Posted by mihit View Post
    My first thought is one brass and one steel, involute.

    My second thought is to dismantle an angle grinder.
    Angle grinder gears are available also as spare parts. Small grinder gears are dirt cheap(something like 4usd per set from aliexpress) but probably underrated for the OP's task.

    230mm/9" angle grinder gears could be enough sturdy, first one that I found on google:
    https://www.ptctools.co.uk/spares3.php/sn/SPARE_GA9020

  9. #9
    Join Date
    Sep 2006
    Location
    Southwestern Ontario, Canada
    Posts
    5,017

    Default

    Quote Originally Posted by SGW View Post
    It's been a while since I read Ivan Law's book (Gears and Gear Cutting) but I do remember that he explains how to cut constant-depth bevel gears. They aren't the same tooth profile as commercial bevel gears, but they are a valid form that work. They can be cut using "normal" shop equipment; they don't require specialized gear-cutting machinery.
    If you want to try cutting bevel gears, I highly recommend that book.
    If you are cutting gears on a mill, using gear cutters, then the constant depth method is the only way you can do it. It is a perfectly valid method, the gears run fine as long as you don't try and mesh them with commercially cut gears.
    The shortest distance between two points is a circle of infinite diameter.

    Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

  10. #10
    Join Date
    Sep 2006
    Location
    Southwestern Ontario, Canada
    Posts
    5,017

    Default

    Quote Originally Posted by BCRider View Post
    component maker like Small Parts. .
    Are Small Parts back in business?? Amazon bought them out at one time and totally buggered them up.
    The shortest distance between two points is a circle of infinite diameter.

    Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •