It's rail
wheels which are beveled, with the radius decreasing to the
outside of the wheel. Your top image has the wheels reversed. There's also a flange which extends below the rail depth on the inner edge of the wheel
Should be, showing from the axel to the rail:
_ __________________________ _
_ __________________________ _
| | | |
| | | |
| | | |
\ | | /
\_| |_/
| |
As the car rounds turns, the inner wheel rides
down and the outer wheel rides
up, increasing the relative rotational radius of the outer wheel. This compensates for the fact that rail wheelsets rotate on a single fixed axis, not independently, and without a differential.
For a non-ASCII image see: https://steemitimages.com/DQmUjS7PbhzAYpkTi5A3c2QQQa7jn1c52s...
Longer explanation: https://www.popularmechanics.com/science/a25581/science-behi...
Wikipedia also discusses geometry: https://en.wikipedia.org/wiki/Train_wheel
Should be, showing from the axel to the rail:
As the car rounds turns, the inner wheel rides down and the outer wheel rides up, increasing the relative rotational radius of the outer wheel. This compensates for the fact that rail wheelsets rotate on a single fixed axis, not independently, and without a differential.For a non-ASCII image see: https://steemitimages.com/DQmUjS7PbhzAYpkTi5A3c2QQQa7jn1c52s...
Longer explanation: https://www.popularmechanics.com/science/a25581/science-behi...
Wikipedia also discusses geometry: https://en.wikipedia.org/wiki/Train_wheel