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

Automotive Chain Drive Differential Gear

  1. Aug 4, 2015 #1
    Hi, I'm a beginner in mechanics so I need some help with a project I started. My project consists of a small kart-like car.

    The car will be Rear-Wheel-Drive and Rear-Engine too (RR layout). and I am willing to use a small 110cc moped engine.

    I have a trike Differential Gear for the rear shaft that I want to use. It has a prop shaft drive.

    I want to change that and convert it into a Chain Drive Differential. Is it possible by adding Sprockets to the ring gear (and opening the differential housing to pass the chain)? can I put the Sprocket outside the housing? or is there a better solution?
    My aim is to mount the chain directly between the engine and the Differential Gear.
  2. jcsd
  3. Aug 4, 2015 #2


    User Avatar

    Staff: Mentor

    I used Google Images and pasted in the title of your thread. I got some very helpful image hits... :smile:
  4. Aug 4, 2015 #3
    You need to think clearly about how the chain can enter and leave the differential housing while maintaing adequate lubrication. If the sprocket is outside the housing, how do you transfer the power to the ring gear without compromising the strength of the differential housing? Is there any reason not to put the sprocket on the differential input shaft and turn the motor 90 degrees?
  5. Aug 9, 2015 #4


    User Avatar
    Science Advisor

    A small moped engine will have a fairly high RPM. You will need a significant reduction ratio set by the size of the chain sprockets. A differential typically has an internal pinion to crown wheel reduction ratio between 3 and 4. That makes the chain reduction ratio less of a problem as the final chain sprocket will be about one third the size needed if the crown wheel was directly driven.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook