Another battery type

[gone-ot]

...wasn't Bill Lear (of Learjet and 8-track tape player fame) involved with "fly-wheel" powered busses at one time too?

[Ken Fry]

Originally Posted by Old Tele man

...wasn't Bill Lear (of Learjet and 8-track tape player fame) involved with "fly-wheel" powered busses at one time too?

I thought so too, but his bus was apparently steam-powered, and the flywheels were applied to a car. Cool guy -- here's an obit which mentions both bus and car.

There were flywheel-powered buses in Sweden or Switzerland several decades ago. They'd spin them up at stops.

[user removed]

The turbos in a B17 had a vertical axis of rotation and spun at 22,000 RPM. When hit by flack or other projectiles they would disintegrate and cut the ball turret in half. They did help to stabilize the plane.

While I understand the dynamics of gyroscopes to a point, it was one of the factors that changed my direction in favor of hydraulic accumulators.

The real question is how much capacitive storage do you really need beyond a single high speed stop or start? From what I have read the energy lost in a 60-0 stop would propel your car down the road at 60 MPH for .7 mile. If you cycled the engine on for .3 mile, the off for .7 mile, it would be about the same as a typical P&G cycle, without speed variations.

Some like to compare this to battery capacity, but that is not really the point. The battery electric cars weakest performance is regenerative braking, as well as P&G type operation. Both of these states of operation are high losses for electric power. Losses in a decent hydraulic system are much lower by a factor of at least half.

regards
Mech

[user removed]

From this site.

http://ecomodder.com/forum/showthrea...ing-20431.html

regards
Mech

[Ken Fry]

Originally Posted by Old Mechanic

While I understand the dynamics of gyroscopes to a point, it was one of the factors that changed my direction in favor of hydraulic accumulators.

And hydraulic accumulators have the advantage of being less expensive and simpler.

The real question is how much capacitive storage do you really need beyond a single high speed stop or start?

Probably, the energy of two stops from 60 is a reasonable lower limit. This allows for a small amount of assist on long hills, permitting the engine to be smaller than it otherwise would be. The Prius shows that this is not always enough, with a Corolla easily beating a Prius up a long hill.

Some like to compare this to battery capacity, but that is not really the point.

Although energy density can be a concern. The UPS hydraulic hybrid had, per Eaton, 2000 hp-seconds (.4kWh) capacity. The accumulators and fluid weighed about 900 lbs. The Prius battery weighs about 100 lbs and has more than three times the energy capacity. (The Li batteries in my POC also weight about 100 lbs, and have 8 times the energy capacity of the Eaton accumulators.)

I hope you will sign up for Doug's "Git er done" challenge. Perfect can be the enemy of the good, and these challenges can help you prioritize what really needs to be done.

Regards, Ken