Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Gear ratio ?

  1. Oct 21, 2005 #1
    Hi , is anyone studying gear ratios??
    i need some help with calculating the final gear drive..
    i've calculated it at 94.97:1
    is this correct??
     

    Attached Files:

  2. jcsd
  3. Oct 21, 2005 #2
    What are these numbers, diameters, radius, number of teeth?
     
  4. Oct 22, 2005 #3
    they are number of teeth.
     
  5. Oct 22, 2005 #4
    Do you want to know whats the end torque? Because without radii, I cant tell you.
     
  6. Oct 22, 2005 #5

    FredGarvin

    User Avatar
    Science Advisor

    Follow the train through logically. Starting at the motor:
    Gear 1 to 2: The speed will step down by a factor of 6/43.

    Gear 2 to 3: The speed should stay the same since they are on the same shaft, so it's ratio could be 1/1

    Gear 3 to 4: The speed is reduced again by a factor of 12/40.

    Gear 4 to 5: Again, they are on the same shaft so the ratio should be 1/1.

    Gear 5 to 6: There is another reduction in speed by a factor of 12/39.

    Gear 6 to 7: Same shaft, no change, 1/1.

    Gear 7 to 8: A final reduction in speed of 12/39.

    So where does that leave you?
     
  7. Oct 23, 2005 #6
    94.62 : 1 thanks fred ..
    how did ya know it was a motor :wink: :smile:
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook