How do trains run without a differential?

Question

As I know, there is no "differential" in trains. How do they mange curves and turns? There must be something with the wheels.

Answer 1

Its just steel wheels on steel rails. No need for differential.

Answer 2

While the curves are gentle, that is of little reason for for the question at hand. No, trains do not have differentials. They use electric motors that are directly coupled to the wheels. These are called traction motors. It is a special compound series motor designed for high starting torque, and moderate to high running speed. Wheel slippage, and gentleness of curves has nothing to do with it. IF one were to lift a locomotive completely off of the tracks, and run the driving engine to full power, the electric motors would continue to accelerate until they came apart. The "engine" is usually a diesel engine driving an alternator that makes electricity. The engineer controls his speed by controlling how much electricity is generated in part by the speed of the diesel, and in part by how much electricity the alternator (generator) produces. This in turn determines how fast the train moves, once it is up to speed.

Answer 3

The curves and turns are so slight that the straight (fixed) wheels can manuver with no problem. If they made the turns sharper then they could derail. Plus the wheel base (length between axles) is short enough to make the turns with out binding. also, if you notice how the wheels sit on the track, its almost the same as a roller coaster. The difference is a roller coaster has and extra wheel to hold it to the rail for the loops and stuff. Trains and train cars can be lifted right off the track.

Answer 4

The cars don't need a differential, they aren't driving the train, and each wheel set is free to spin on it's own axle.
The engines have a different setup, with each electric motor driving two wheels thru a gearbox. The gear box has a clucth-like disk that disconnects the wheel that doesn't spin as fast as the other.
Trains normally travel on tracks that have very gentle curves, but they do pass thru yards and sidings where the curves can be very sharp. That's when you'll hear all the squeals and shreaks as the cars are forced thru tight switches and bends.

Answer 5

By differentials I'm guessing you are talking about the drive train? The way a locomotive moves is by a diesel motor inside the engine operates a generator and a air com-presser. As you increase the rpm's of the diesel you create amperage which drives the electric motors which in turn moves the wheels by a very large bunch of gears."To put it simply." The air com-presser supplies air to the train line so that you can stop the train with the brakes on the cars.

Answer 6

You have the radius of the curve which is slight and gradual which will cause a minimal amount of slippage,and if the rail is wet or greased you can have what they call flat spots in the rail and wheel.Reason is with no differential both wheels spin at same rate wearing down rail and wheel. In both cases they have to be ground to be repaired or replaced.The reasoning for no differential is to provide the most torque with as little horsepower loss as possible.

Answer 7

truly a custom wheelset *ought to* *no longer* have a differential for the taper to artwork as meant. even as the wheelset runs by skill of a curve the automobile is pulled to the outdoors by using the centrifugal rigidity (or in different words: it needs to proceed on its immediately course - inertia at its superb *g*). even as that occurs the outer wheel climbs a touch onto its taper for this reason getting an more advantageous diameter with appreciate to the rail (the option occurs for the wheel operating on the in the curve). Now you truly have a wheelset the position the wheels have different diameters (wrt to the position they contact the rails). you are able to imagine of it as an excellent cone. Now imagine what occurs whenn you roll a cone round on a table: it runs in curves! So the style of the wheels jointly with the fixed axle truly helps to teach the wheelset around the curve. lower than widespread situations the wheels flanges under no circumstances favor to the contact the rails in any respect. This in trouble-free words works *because* there is not any differential and both wheels always run with an same rpm.

Answer 8

The axles of the cars are indeed locked together. The curves are so gradual that wheel slippage is minimal. That's the high pitched squealing you hear when the train rounds a curve.

Answer 9

The corners are not curvered enough to reguire a differential. Also a certain amount of slippage is allowed between the track and the wheels.

Answer 10

Because train tracks are not flat, they have a slight curved top surface. The curves are quite gentle and the wheel has a slight taper from the flange to the outside edge. This allows the wheel on the outside of the curve to run on the larger diameter of the wheel, next to the flange. On the inside of the curve the wheel runs on the taper of the curve at the smaller diameter of wheel. In effect this give the slight differential needed to negotiate the gentle curves of the railroad tracks.