Diesel trains use electric motors because the low-end torque is much greater than a mechanical drive drive train, I was wondering, since low-end torque is essential to starting with heavy dead weight, why more trucks and SUVs don't have electric motors on the wheels?
For most part, it has to do with reliability. A train runs on a set track, so no ups and downs and bumps and whatnot. Nothing under the tracks that'll come up and snag the bottom, that sort of thing. A truck on the other hand, do drive over things, and the wheels go up and down bazillion times, and all that. A truck's wheel hubs are designed to be as simple and robust as possible for maximum reliability. Adding a motor to the hub would decrease its ground clearance, decrease reliability, and if one of the motors fail the vehicle can't really run on the rest (assuming all wheels are powered) as it produces asymmetrical thrust. So you have to disconnect the matching one on the other side. The designers basically judged that currently, the technology cannot compensate enough for the advantages to outweigh the disadvantages. A while back, Ford was considering a system called gas-operated launch assist. Basically, it operates similar to the way a hybrid stores electricity generated from braking, and releases it back for acceleration. However, instead of doing battery/motor/generator, it uses a compressible gas as the energy storage medium. While driving and braking, gas is compressed into the the cylinder. When the start starts moving again, the gas is allowed to expand, adding a bit of oomph to the launch. Apparently, that idea didn't go anywhere, but it was interesting. And Dodge actually built a special hybrid Durango that only had the gas engine drive one set of wheels, and electricity drive the other set of wheels. It is much easier and cheaper to make than a regular hybrid, but apparently the traction control is giving them problems to coordinate between the two drivetrain systems. --- Kasey C, PC guru since Apple II days Borg Burgers: Have it our way. Yours is irrelevant.
There are a lot of hybrid vehicles out there. The diesel locomotive is a hybrid the internal combustion engine/s turn generators which in turn power the wheels. Other heavy equipment such as used at strip mining sites also uses the same technology. But in general it is cheaper, and more reliable to have as few of moving parts as possible. A hybrid vehicle has more systems to fail then one with gear drive. Also in the case of locomotives that additional weight required for such systems is a benefit, while in a over the road vehicle is it a liability.
Have you check the price of gas lately??? It has gone up over $.45 cents a gallon since August by memorial day gas will over $3.75 for premium gas. The, muscle cars and trucks will be built lighter and more fuel efficient. Gas. will be reaching about $4.50 a gallon in about 1 1/2 years. Government standards are also having effect on gas mileage of future cars and trucks. Back in the old days! muscle cars were getting around 8-12 mpg and then there were gas stations on every corner and gas was selling for $.18-.25 cents a gallon. About 1974 gas hit and all time price record of $.50 cents per gallon. There were gas lines and gas shortages etc.
Diesel powered trains are hybrid vehicles because the diesel engine turns an electric generator and the electricity is used to turn an electric motor which drives the wheels. This technology is great if you don't need to worry about acceleration and braking speeds and don't have any weight limits, but SUVs and trucks have to travel over highways, bridges and roadways and blend in with other cars and trucks. While there are a few hybrid SUVs and light trucks being sold today, the technology is just not there yet to make it practical or affordable for all applications. Maybe sometime in the future
