live axels vs wheels
live axels vs wheels
(OP)
I need to know which would be better in handling heavy loads at high speeds, a live axle or free turning wheels? I'm looking at 20 axles 2 inches in diameter. Forty steel wheels, 24-28 inches in diameter and 2 inches wide, and being somewhat aerodynamically shaped and a traveling speed of 250mph. All rolling on a flat rail with no flanges carrying about 200,000 lbs.





RE: live axels vs wheels
The wheels are tapered (or rounded), such that the outside has a smaller diameter than the inside, and are fixed in pairs to axles. If one wheel tries to get ahead of another wheel (as though the bogey is trying to steer off of the tracks), the forward wheel starts to ride on a smaller radius, and the lagging wheel starts to ride on a larger radius. Since the two wheels turn at the same speed (fixed to axle), the forward (outside of turn) one begins to travel more slowly than the lagging (inside of turn) one, and they return to travelling straight-ahead. The tracks are rounded to meet the wheels appropriately (I don't know the details of the track shape).
I wonder how a train would stay on flat tracks?
RE: live axels vs wheels
Roller coasters use another set of wheels running sideways on the edge of their rails, but they carry very light loads and have polyurethane tires on their wheels. They also don't go near 250 mph.
RE: live axels vs wheels
RE: live axels vs wheels
luck
rentapen
RE: live axels vs wheels
http://www.timken.com/products/bearings/products/ap/Ap-Sp.asp
RE: live axels vs wheels
RE: live axels vs wheels
RE: live axels vs wheels
RE: live axels vs wheels
But all road vehicles use the inner free wheeling method. Which is limited to spreading the forces over a larger area then would be needed in a solid configuration whose area would be smaller. If you have the room go for a free turning.
rentapen
toledo, ohio
train capital of the world.
RE: live axels vs wheels
What determins the choice of steel vrs rubber whells? I would guess that rubber is better where you need to make lots of stops and starts and steel is better for long runs.
ProEpro
RE: live axels vs wheels
Rubber does not work well as a wheel in the solid form.
A pneumatic tire for todays technology would be limited in pressure for a real world operation. This is going to generate a lot of heat at 250 mph.
Sure, land speed racers run those speeds and many applications use high pressure tires, but they are not expected to last long.
Also consider the rolling friction and rotating air friction of a rubber tire versus a steel wheel. You would need a couple of extra engines to turn all that mass.
'Course, someone will decide this is just a design challenge and they are going that way anyhow.
It is not just starting and stopping. Steel-wheel-steel-rail has poor grade climbing ability, as well.
Stick with the proven solid axle tapered wheel design for high speed transport.
Crashj 'big wheels keep on rolling' Johnson
RE: live axels vs wheels
250 m.p.h. brakes would be a concern. What ever this
thing is I'd like to see it go.
RE: live axels vs wheels