Fuel Savings from Roadbed Electrification Pays for the Power

[Bret Cahill]

If you aren't in the public record, you haven't done anything.

Since your only public record appears to be lots of Internet babble, I
guess you haven't done anything.

I donno. Mr Cahill seems to avoid the technical merits of people's
arguments

Telling everyone to read a "pop book" ain't no technical argument.

d asks them to make an appeal to authority fallacy,

_You_ are the one giving out reading lists.


Bret Cahill

 

[John Stafford]

On 6/4/09 3:09 PM, in article
abd30048-e9e0-40f4-9978-796ba4411318@f16g2000vbf.googlegroups.com,
"tgdenning@earthlink.net" <tgdenning@earthlink.net> wrote:

On Jun 4, 10:22 am, john joseph <nowh...@nowhere.nl> wrote:

Oh, check this out:http://www.pmlflightlink.com/news.html


Thanks. These are the people involved in this:

http://www.hipadrive.com/Documents/new%20york%20times%20sema%20article.pdf

I should point out, however, that in-the-hub isn't a *requirement* to
benefit from wheelmotors. Nice, but not necessary.

Can you point me to a wheelmotor that is not in the hub?

 

[Bret Cahill]

Unsprung weight in an automobile (motorcycle, bicycle, etc.) typically
is in the wheels before the suspension and is a concern largely for high
performance and ordinary performance on imperfect roads. There are
vehicles with the motor(s) in the hubs of the wheels. Conventional
affordable electric engines tend to be quite heavy (emphasis on
economical because if you wish to spend enough, this weight can be
dramatically reduced.)

He wants to know why heavy wheels were ever an issue in the first
place.

Check out how I set up the equation of motion for vehicle suspension.

To keep things easy I replaced the seemingly passive pot hole forcing
function with an active forcing function that was proportional to the
weight of the wheels.

The proposal for electrified roads suggests that these roads could be
made quite smooth and turns radiused and possibly banked to reduce the
need for less unsprung weight. It's all a trade-off.

Smoother roads would nice but the typical freeway surface may be good
enough.

One issue is the truck lane which generally is in pretty sorry shape.

I am particularly interested in carbon-fiber wheels but they are not DOT
approved for road use and regardless, changing the tires is very
difficult to do without damaging the rims.

Oh, check this out:http://www.pmlflightlink.com/news.html

The article in that link is problematic in one regard, "Torque Ripple"
is actually beneficial to traction as evinced in such applications as
"big bang" engines which are either engines with, for example, two
cylinders firing in 45 degree or less (Suziki, Harley-Davidson, Honda's
V4 modified to two oval cylinders and four connecting rods) and an
exotic 16 cylinder engine that fires four cylinders at once.

The same 'ripple' or pulsed power effect is what makes anti-lock brakes
more effective than conventional.

We need to figure out a way to get cheap energy to the vehicle.

Otherwise I'll start advocating spray painting "Bicycle Only" on every
other road like they do in platinum rated bicycle friendly cities.


Bret Cahill

 

On Jun 4, 10:22 am, john joseph <nowh...@nowhere.nl> wrote:

Unsprung weight in an automobile (motorcycle, bicycle, etc.) typically
is in the wheels before the suspension and is a concern largely for high
performance and ordinary performance on imperfect roads. There are
vehicles with the motor(s) in the hubs of the wheels. Conventional
affordable electric engines tend to be quite heavy (emphasis on
economical because if you wish to spend enough, this weight can be
dramatically reduced.)

The proposal for electrified roads suggests that these roads could be
made quite smooth and turns radiused and possibly banked to reduce the
need for less unsprung weight. It's all a trade-off.

I am particularly interested in carbon-fiber wheels but they are not DOT
approved for road use and regardless, changing the tires is very
difficult to do without damaging the rims.

Oh, check this out:http://www.pmlflightlink.com/news.html

Thanks. These are the people involved in this:

http://www.hipadrive.com/Documents/new%20york%20times%20sema%20article.pdf

I should point out, however, that in-the-hub isn't a *requirement* to
benefit from wheelmotors. Nice, but not necessary.

-tg

The article in that link is problematic in one regard, "Torque Ripple"
is actually beneficial to traction as evinced in such applications as
"big bang" engines which are either engines with, for example, two
cylinders firing in 45 degree or less (Suziki, Harley-Davidson, Honda's
V4 modified to two oval cylinders and four connecting rods) and an
exotic 16 cylinder engine that fires four cylinders at once.

The same 'ripple' or pulsed power effect is what makes anti-lock brakes
more effective than conventional.

 

On Jun 4, 2:27 pm, John Stafford <jstaff...@winona.edu> wrote:

On 6/3/09 10:29 AM, in article
8ac333b5-c882-4d32-a4e0-2ef713745...@o20g2000vbh.googlegroups.com,

"tgdenn...@earthlink.net" <tgdenn...@earthlink.net> wrote:

Replacing the battery will, however, costs 3X more than the
electricity so you'll be paying $2.70/gal equiv.

Except that I will be saving (more than) the cost of the battery by
eliminating the transmission and the brakes and the lifetime
maintenance of the all the fluids and so on. I can build a *more
capable* car for half the money, excluding the battery, because the
motive system will become commodified. So now I am back to paying
that 70 cents per gal equivalent.

This link shows one of my cars. It was originally an electric car. Now it
has a 165HP aircooled gasoline engine. Batteries then (seventies) were way
too much of a hassle, and expensive. One nice thing was that I could
eliminate the transmission.

I still have it. Recent snapshot:http://www.digoliardi.net/images/002.jpg

Sweet.

-tg

Why should I care if the battery is a big part of the cost of the
car---I'm only interested in the total cost over the car's lifetime,
which will be greatly extended.

Batteries are still rather expensive. Heck, they charge $5 to throw one away
here!

 

On Jun 4, 10:33 am, Bret Cahill <BretCah...@peoplepc.com> wrote:

If all the components are there, why isn't someone becoming filthy
rich building your wet dream on wheels?

Because gas is still cheap?

No, because batteries are still expensive.

TN Val Auth will sell locals 6 GW for 70 cents/gal equivalent if they
charge up at night.

Replacing the battery will, however, costs 3X more than the
electricity so you'll be paying $2.70/gal equiv.

Except that I will be saving (more than) the cost of the battery by
eliminating the transmission and the brakes and the lifetime
maintenance of the all the fluids and so on.

These are not significant _operating_ costs.  They don't cost anything
on a _per mile_ basis.

The battery, while it is part of the initial cost, is also part of the
operating cost because it must be replaced every few years.  This
isn't true for a transmission.

I can build a *more
capable* car for half the money, excluding the battery,

But the 800 lb gorilla cost is the operating cost of the battery.

because the
motive system will become commodified. So now I am back to paying
that 70 cents per gal equivalent.

If you are charging and discharging a battery, you will always be
paying at least $2.70/gallon.

The $10,000 battery needs to be replaced several times over the cars
lifetime.

Now, if you want, you can calculate battery cost as part of the
initial cost.  Just pay for all the necessary batteries up front and
your $20,000 EV will cost $60,000.

Which is fine with me, since the electric motors will last forever.
Say you replace a battery every 10 years. My initial cost without the
battery will be 15K for a very nice vehicle. I run the car for 30
years, so my cost is 1.5K per year. And I pay that .70 per gallon for
fuel.

The problem with your plan, Bret, is not 'baby steps' as you suggest,
but chicken and egg. You don't build the electrified highway until
there are 60 million EV's on the road, so first you have to give
people better cars at lower prices. Check out that 600 hp F-150:

http://www.hipadrive.com/Documents/new%20york%20times%20sema%20article.pdf

When those are all over the trailer park, the congressman won't be
taking his life into his hands as an unamericun muslim commie when he
suggests the third rail on the interstate.

So no matter how you try to calculate it, the battery cost is the
killer.

Why should I care if the battery is a big part of the cost of the
car---I'm only interested in the total cost over the car's lifetime,
which will be greatly extended.

Any street mohead can convert any old pu or SUV to an EV for less than
what anyone could sell a new EV.

Only in Cuba. They put old Soviet military truck drivetrains into 1957
Impalas, so they could probably do this without even a screwdriver.

-tg

Why isn't this more common?  Because of the battery cost.

Bret Cahill

 

On Jun 4, 4:25 pm, John Stafford <jstaff...@winona.edu> wrote:

On 6/4/09 3:09 PM, in article
abd30048-e9e0-40f4-9978-796ba4411...@f16g2000vbf.googlegroups.com,

"tgdenn...@earthlink.net" <tgdenn...@earthlink.net> wrote:
On Jun 4, 10:22 am, john joseph <nowh...@nowhere.nl> wrote:
Oh, check this out:http://www.pmlflightlink.com/news.html

Thanks.  These are the people involved in this:

http://www.hipadrive.com/Documents/new%20york%20times%20sema%20articl...

I should point out, however, that in-the-hub isn't a *requirement* to
benefit from wheelmotors.  Nice, but not necessary.

Can you point me to a wheelmotor that is not in the hub?

You know, I am posting from a philosophy group, and this kind of
definition thing is always lots of trouble. The people in the
reference make flat motors, and so it is in their interest to think in-
the-hub. If you mount four electric motors to the chassis, and have
some kind of universal-joint stub connected to the wheel, what do you
call that other than a wheelmotor?

What I'm pushing in these posts is the idea of multiple companies
making motors with whatever innovative de-coupling of the mass of the
electric motor from the 'sprung' mass of the 'wheel' they can come up
with. The chassis has some mounting points, but the rest of it is
subject to the creativity or stupidity of the motor people.

Yeah, I know, I'm a crazy free-market optimist. If you have the chops
to put together those cars, why don't you try it yourself?

-tg

 

[john joseph]

tgdenning@earthlink.net wrote:

On Jun 4, 4:25 pm, John Stafford <jstaff...@winona.edu> wrote:

Can you point me to a wheelmotor that is not in the hub?

You know, I am posting from a philosophy group, and this kind of
definition thing is always lots of trouble. The people in the
reference make flat motors, and so it is in their interest to think in-
the-hub. If you mount four electric motors to the chassis, and have
some kind of universal-joint stub connected to the wheel, what do you
call that other than a wheelmotor?

No. That's just another inboard motor arrangement. You see, in the case
you described the motors would be above the suspension.

What I'm pushing in these posts is the idea of multiple companies
making motors with whatever innovative de-coupling of the mass of the
electric motor from the 'sprung' mass of the 'wheel' they can come up
with.

It is very simple. Think of motors in a wheel bouncing down the road.
Heavy is not good because too much energy is fed right back to them
because the suspension cannot transfer it quickly enough to some
putative absorber in the chassis.

However, if one distributes the total desired power among four wheels,
then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I know this
shit.

 

[john joseph]

tgdenning@earthlink.net wrote:

On Jun 4, 10:33 am, Bret Cahill <BretCah...@peoplepc.com> wrote:

The $10,000 battery needs to be replaced several times over the cars
lifetime.

Now, if you want, you can calculate battery cost as part of the
initial cost. Just pay for all the necessary batteries up front and
your $20,000 EV will cost $60,000.


Which is fine with me, since the electric motors will last forever.

Only if forever is something like 8,000 working hours.

 

[Eeyore]

Bret_E_Cahill@yahoo.com wrote:

The single magic bullet solution folk need to be lined up and . . .

The only magic bullet needed here is the one required to terminate what must be
loosely called your 'brain'. You're daft beyond belief.

Graham

due to the hugely increased level of spam please make the obvious adjustment to
my email address

 

[Eeyore]

John Larkin wrote:

Bret_E_Cahill@yahoo.com wrote:

Or you could use bio fuel in your plug in hybrid's tank.

Hey, we could have biofuel reloading facilities near every freeway! We
could call them something catchy like "filling stations" maybe. Maybe
have statues of Al Gore out front.

Preferably showing him being hung by the neck. That man's a creep out to get
even richer by frightening people into doing what he says by using LIES whilst
flagrantly ignoring his own advice as regards his personal energy use.

Graham

--
due to the hugely increased level of spam please make the obvious adjustment to
my email address

 

[Bret Cahill]

If all the components are there, why isn't someone becoming filthy
rich building your wet dream on wheels?

Because gas is still cheap?

No, because batteries are still expensive.

TN Val Auth will sell locals 6 GW for 70 cents/gal equivalent if they
charge up at night.

Replacing the battery will, however, costs 3X more than the
electricity so you'll be paying $2.70/gal equiv.

Except that I will be saving (more than) the cost of the battery by
eliminating the transmission and the brakes and the lifetime
maintenance of the all the fluids and so on.

These are not significant _operating_ costs. �They don't cost anything
on a _per mile_ basis.

The battery, while it is part of the initial cost, is also part of the
operating cost because it must be replaced every few years. �This
isn't true for a transmission.

I can build a *more
capable* car for half the money, excluding the battery,

But the 800 lb gorilla cost is the operating cost of the battery.

because the
motive system will become commodified. So now I am back to paying
that 70 cents per gal equivalent.

If you are charging and discharging a battery, you will always be
paying at least $2.70/gallon.

The $10,000 battery needs to be replaced several times over the cars
lifetime.

Now, if you want, you can calculate battery cost as part of the
initial cost. �Just pay for all the necessary batteries up front and
your $20,000 EV will cost $60,000.

Which is fine with me,

Maybe _you_ can afford $40,000 worth of batteries but it won't be fine
with the _majority_ of motorists who don't have $60,000 to pay for a
motor vehicle.

You wanted to know why there aren't any EVs.

Well that's one reason. The batteries make it more expensive than $3
gallon fuel.

The other reason is convenience, or at least imagined convenience.
The oil companies have everyone assuming all kinds of unlikely
situations, i.e., you return from work and absolutely must drive coast
to coast in 3 days on a moment's notice.

It's one of those Big Lies that fly under radar but I'm not going to
fight it.

It's easier to just make it possible for EVs to have the same
capability.

since the electric motors will last forever.

Windshields can last forever too but that doesn't wipe out the $40 K
you _must_ spend on batteries.

Say you replace a battery every 10 years.

A pipe dream.

That might not be possible even if you're not driving the car very
much. Maybe granny can use an EV to drive to church every Sunday but
it's not going to satisfy most motorists.

In the desert SW a lead acid battery lasts 3 years even if you aren't
using it much.

My initial cost without the
battery will be 15K for a very nice vehicle. I run the car for 30
years, so my cost is 1.5K per year. And I pay that .70 per gallon for
fuel.

You don't seem to understand. A battery isn't like a watch spring.
Batteries only take a limited number of charges, ~ 1000 for Li -
Ion.

It's like getting into a taxi. You aren't paying just by time but by
the mile, at least $2/gallon equiv for the battery and about $1.50/
gallon equiv for the electricity in most places.

The 70 /gallon equiv figure is only in the TVA area and parts of
Canada.

The problem with your plan, Bret, is not 'baby steps' as you suggest,
but chicken and egg. You don't build the electrified highway until
there are 60 million EV's on the road,

Maybe a few Hollywood types will buy an EV that costs $60,000 over
it's lifetime.

Only government can really get things going for the general public.

That is best done with roadbed electrification.

first you have to give
people better cars at lower prices.

That would require a lower priced battery which does not exist.

There are two choices:

Government pays every motorist $40,000 for batteries and does nothing
to help motorists drive non stop coast to coast.

Cost: $4 trillion. (Reaganitics have political weapon: gummint
giving out welfare battery vouchers.)

Government pays to electrify 100,000 miles of freeway at a cost of $10
million/mile. Convenient grid powered coast to coast travel becomes
possible.

Cost: $1 trillion (Reaganitics fume but cannot say anything as it's
just highway construction.)


Bret Cahill

 

[john joseph]

tgdenning@earthlink.net wrote:

On Jun 4, 8:58 pm, john joseph <nowh...@nowhere.nl> wrote:

It is very simple. Think of motors in a wheel bouncing down the road.
Heavy is not good because too much energy is fed right back to them
because the suspension cannot transfer it quickly enough to some
putative absorber in the chassis.

However, if one distributes the total desired power among four wheels,
then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I know this
shit.

Glad to hear it. I like to talk to people who know what they are
talking about. However, my point does not change---the benefit of 4
electric motors is pretty much the same even if they are 'mounted
inboard'. I am not interested in worrying about what you call them.

Never seen "inboard" mounted wheels on an autombile. What would they
look like?

Regardless, more motors means more likelihood of failure of one and
compounded loss of reliability/efficiency for all of them. It's a trade
off: with four in-hub motors you can have four weaker, lighter wheel
motors rather than one big motor in the chassis.

You also posted something about 8,000 hours for an electric motor
lifetime. Where do you get that figure? And what is the failure mode?

That was probably wrong. I built a couple in-hub brushed electric
bicycles (front hub) and 8,000 hours was the figure for them. (The
brushes lasted longer than the motors. Real crap that those motors
were.) It depends upon the motor and operation, of course. I can't even
guess what an arbitrarily chosen in-hub motor for an automobile would
get and I'm about to leave for the day job so I don't have time to
research it.

Regarding mode, a catastrophic failure (sudden, all at once) can occur
in a brushed engine, or through bearing failures of any. We don't have
air bearings for large engines yet. However, electric engine
performance usually (depending upon type) diminishes long before failure
so you have to look to the reliability as performance figures rather
than MTBF.

 

On Jun 4, 8:58 pm, john joseph <nowh...@nowhere.nl> wrote:

tgdenn...@earthlink.net wrote:
On Jun 4, 4:25 pm, John Stafford <jstaff...@winona.edu> wrote:
Can you point me to a wheelmotor that is not in the hub?

You know, I am posting from a philosophy group, and this kind of
definition thing is always lots of trouble. The people in the
reference make flat motors, and so it is in their interest to think in-
the-hub. If you mount four electric motors to the chassis, and have
some kind of universal-joint stub connected to the wheel, what do you
call that other than a wheelmotor?

No. That's just another inboard motor arrangement. You see, in the case
you described the motors would be above the suspension.

What I'm pushing in these posts is the idea of multiple companies
making motors with whatever innovative de-coupling of the mass of the
electric motor from the 'sprung' mass of the 'wheel' they can come up
with.  

It is very simple. Think of motors in a wheel bouncing down the road.
Heavy is not good because too much energy is fed right back to them
because the suspension cannot transfer it quickly enough to some
putative absorber in the chassis.

However, if one distributes the total desired power among four wheels,
then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I know this
shit.

Glad to hear it. I like to talk to people who know what they are
talking about. However, my point does not change---the benefit of 4
electric motors is pretty much the same even if they are 'mounted
inboard'. I am not interested in worrying about what you call them.

You also posted something about 8,000 hours for an electric motor
lifetime. Where do you get that figure? And what is the failure mode?

-tg


-tg

 

On Jun 5, 8:13 am, john joseph <nowh...@nowhere.nl> wrote:

tgdenn...@earthlink.net wrote:
On Jun 4, 8:58 pm, john joseph <nowh...@nowhere.nl> wrote:

It is very simple. Think of motors in a wheel bouncing down the road.
Heavy is not good because too much energy is fed right back to them
because the suspension cannot transfer it quickly enough to some
putative absorber in the chassis.

However, if one distributes the total desired power among four wheels,
then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I know this
shit.

Glad to hear it. I like to talk to people who know what they are
talking about. However, my point does not change---the benefit of 4
electric motors is pretty much the same even if they are 'mounted
inboard'. I am not interested in worrying about what you call them.

Never seen "inboard" mounted wheels on an autombile. What would they
look like?

http://teslamotorsclub.com/technical/303-hub-motors-dual-motors.html

Scroll down to number 8 I think. I would dispense with disc brakes on
the wheel and put some very simple parking-brake device on the inboard
side as a 'final ultimate' emergency stopping option, relying on
electric braking.

Regardless, more motors means more likelihood of failure of one and
compounded loss of reliability/efficiency for all of them.  It's a trade
off: with four in-hub motors  you can have four weaker, lighter wheel
motors rather than one big motor in the chassis.

I think reliability has to be thought of differently from the simple
formula. You could argue that a car with 4 tires is more likely to
have a flat than a motorcycle with two, but that doesn't make me feel
that motorcycles are safer than cars.

The idea, which I've repeated many times now, is that the market will
yield better motors if there are 40 million sold in the US every year
rather than 10 million. And a motor that weighs 75 lbs is easy to
swap out; I think electric motors can be rebuilt a couple of times at
least---and much easier than rebuilding an ICE or a transmission.

 > You also posted something about 8,000 hours for an electric motor
 > lifetime. Where do you get that figure? And what is the failure mode?

That was probably wrong. I built a couple in-hub brushed electric
bicycles (front hub) and 8,000 hours was the figure for them. (The
brushes lasted longer than the motors. Real crap that those motors
were.)  It depends upon the motor and operation, of course. I can't even
guess what an arbitrarily chosen in-hub motor for an automobile would
get and I'm about to leave for the day job so I don't have time to
research it.

I'm pretty sure lifetimes are rated much higher for brushless electric
motors. But just think--- if you average 40mph, 8,000 hours would get
you 320,000 miles. And if you have to replace brushes, so what?

As I said before, I don't know what the best type of electric motor
will end up being used---maybe different for different applications.

-tg

Regarding mode, a catastrophic failure (sudden, all at once) can occur
in a brushed engine, or through bearing failures of any. We don't have
air bearings for large engines yet.  However, electric engine
performance usually (depending upon type) diminishes long before failure
so you have to look to the reliability as performance figures rather
than MTBF.

 

In sci.physics Bret Cahill <BretCahill@peoplepc.com> wrote:

Government pays to electrify 100,000 miles of freeway at a cost of $10
million/mile. Convenient grid powered coast to coast travel becomes
possible.

As there are roughly 210,000 lane miles of freeway in the US, what about
the other half?

$10 million/mile doesn't buy much more than paving these days.

I suppose all the electification equipment capital and installation costs
are free?



--
Jim Pennino

Remove .spam.sux to reply.

 

[John Stafford]

On 6/5/09 7:52 AM, in article
a187370d-0d8a-4565-8cb8-407364942aba@d31g2000vbm.googlegroups.com,
"tgdenning@earthlink.net" <tgdenning@earthlink.net> wrote:

On Jun 5, 8:13 am, john joseph <nowh...@nowhere.nl> wrote:
tgdenn...@earthlink.net wrote:
On Jun 4, 8:58 pm, john joseph <nowh...@nowhere.nl> wrote:

It is very simple. Think of motors in a wheel bouncing down the road.
Heavy is not good because too much energy is fed right back to them
because the suspension cannot transfer it quickly enough to some
putative absorber in the chassis.

However, if one distributes the total desired power among four wheels,
then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I know this
shit.

Glad to hear it. I like to talk to people who know what they are
talking about. However, my point does not change---the benefit of 4
electric motors is pretty much the same even if they are 'mounted
inboard'. I am not interested in worrying about what you call them.

Never seen "inboard" mounted wheels on an autombile. What would they
look like?

http://teslamotorsclub.com/technical/303-hub-motors-dual-motors.html

That is not an inboard hub motor. It is not a hub motor at all. It is a
perfectly conventional motor. A hub motor is inside the wheel, not just
something that drives the hub. There are no motors or engines that drive the
wheel anywhere but to the hub. None drive at the rim of the wheel (except
for a couple exotic show motorcycles that are impractical. Citations
available.)

If I were home I'd shoot some pics of the Porsche's IRS and you would see
it's connected to the transmission just like that illustration done by the
would-be impressionistic, unlearned contributor to the site in question.

So, let's stick to real-world terms. I would not use the post in question as
a source of any authority.

Scroll down to number 8 I think. I would dispense with disc brakes on
the wheel and put some very simple parking-brake device on the inboard
side as a 'final ultimate' emergency stopping option, relying on
electric braking.

Old hat. We have been mounting disc brakes on drive shafts for many years. I
think Lotus does it. I have done it. You can't turn a disc brake into a
generator. Its lack of a flywheel effect and radius make it impractical, and
also consider that all electric motors are also generators, but not
particularly powerful.

The idea, which I've repeated many times now, is that the market will
yield better motors if there are 40 million sold in the US every year
rather than 10 million. And a motor that weighs 75 lbs is easy to
swap out; I think electric motors can be rebuilt a couple of times at
least---and much easier than rebuilding an ICE or a transmission.

Yup, rather like the original Jeep - lots of 'em, bolt access outside of the
obstructions, all that.

 > You also posted something about 8,000 hours for an electric motor
 > lifetime. Where do you get that figure? And what is the failure mode?

That was probably wrong. I built a couple in-hub brushed electric
bicycles (front hub) and 8,000 hours was the figure for them. (The
brushes lasted longer than the motors. Real crap that those motors
were.)  It depends upon the motor and operation, of course. I can't even
guess what an arbitrarily chosen in-hub motor for an automobile would
get and I'm about to leave for the day job so I don't have time to
research it.

I'm pretty sure lifetimes are rated much higher for brushless electric
motors. But just think--- if you average 40mph, 8,000 hours would get
you 320,000 miles. And if you have to replace brushes, so what?

I don't know if brushless motors would work with a purely electric
(non-hybrid) car. They have to be nudged into motion before the fields
engage. Brushes are necessary to move off a dead stop (or the hybrid motor
has to nudge it.)

Remember, too, these are probably three-phase motors. Three phase motor
fields must be kept synchronized in each motor or they become quite
inefficient.

FWIW, I know a fellow in France who has a Tesla. He's a bit unhappy about
the recall. I'm looking forward to his driving impression.

 

[Bill Ward]

On Fri, 05 Jun 2009 09:48:31 -0700, tgdenning wrote:

On Jun 5, 11:26 am, John Stafford <jstaff...@winona.edu> wrote:
On 6/5/09 7:52 AM, in article
a187370d-0d8a-4565-8cb8-407364942...@d31g2000vbm.googlegroups.com,



"tgdenn...@earthlink.net" <tgdenn...@earthlink.net> wrote:
On Jun 5, 8:13 am, john joseph <nowh...@nowhere.nl> wrote:
tgdenn...@earthlink.net wrote:
On Jun 4, 8:58 pm, john joseph <nowh...@nowhere.nl> wrote:

It is very simple. Think of motors in a wheel bouncing down the
road. Heavy is not good because too much energy is fed right back
to them because the suspension cannot transfer it quickly enough
to some putative absorber in the chassis.

However, if one distributes the total desired power among four
wheels, then each will be lighter and life is good again.

My friend, I have been building race setups for forty years. I
know this shit.

Glad to hear it. I like to talk to people who know what they are
talking about. However, my point does not change---the benefit of 4
electric motors is pretty much the same even if they are 'mounted
inboard'. I am not interested in worrying about what you call them.

Never seen "inboard" mounted wheels on an autombile. What would they
look like?

http://teslamotorsclub.com/technical/303-hub-motors-dual-motors.html

That is not an inboard hub motor. It is not a hub motor at all. It is a
perfectly conventional motor. A hub  motor is inside the wheel, not
just something that drives the hub. There are no motors or engines that
drive the wheel anywhere but to the hub. None drive at the rim of the
wheel (except for a couple exotic show motorcycles that are
impractical. Citations available.)

You lost me there---I'm in favor of using perfectly conventional motors
if that works.


If I were home I'd shoot some pics of the Porsche's IRS and you would
see it's connected to the transmission just like that illustration done
by the would-be impressionistic, unlearned contributor to the site in
question.


The picture is just so people can visualize the possible configuration.
I don't see anything wrong with it.


So, let's stick to real-world terms. I would not use the post in
question as a source of any authority.

Scroll down to number 8 I think.  I would dispense with disc brakes
on the wheel and put some very simple parking-brake device on the
inboard side as a 'final ultimate' emergency stopping option, relying
on electric braking.

Old hat. We have been mounting disc brakes on drive shafts for many
years. I think Lotus does it. I have done it. You can't turn a disc
brake into a generator. Its lack of a flywheel effect and radius make
it impractical, and also consider that all electric motors are also
generators, but not particularly powerful.

Again you've lost me---you are obviously misinterpreting what I said.
Braking is done by the electric motor; for most of the braking period
you are recovering the kinetic energy, which is why it is called
regenerative braking. The ultimate implementation would have no disc
brakes at all. If you need further explanation please let me know.

Motor/generators are transducers, not brakes. That means you can only
slow down, not come to a complete stop. If the electronic controller
failed, you couldn't even slow down. How big a market do you expect for
cars without brakes?

Remember, everything looks easy to the guy who doesn't actually have to
do it.

snip>

 

In sci.physics Bret Cahill <BretCahill@peoplepc.com> wrote:

Government pays to electrify 100,000 miles of freeway at a cost of $10
million/mile. �Convenient grid powered coast to coast travel becomes
possible.

As there are roughly 210,000 lane miles of freeway in the US, what about
the other half?

The #1 and 2 lanes are for those who have already charged up in the #3
and # 4 lanes.

The majority of the freeway lane miles are 2 lanes once you are outside
the urban areas.

They are also for motorcyclists who don't want their tires to get
trapped in the slot

We've beaten this to death.

Conductors in the road won't work in the real world weather.

Overhead conductors won't work with the vehicle mix.

The only way to electrify existing roads and still carry the existing
traffic is to use induction.

$10 million/mile doesn't buy much more than paving these days.

Is that $10 million per mile or mile lane?

I suppose all the electification equipment capital and installation costs
are free?

By your numbers rebuilding the entire Eisenhower system would be 2.1
trillion.

Probably about right in 2009 dollars.

We spend that every 4 years on foreign fuel.

Irrelevant.

We spend about the same every 4 years on welfare too.

Neither is relevant to the cost of rebuilding the highway system.

<snip childish insult attempts to divert the topic>

--
Jim Pennino

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In sci.physics Bret Cahill <BretCahill@peoplepc.com> wrote:

Regardless, more motors means more likelihood of failure of one and
compounded loss of reliability/efficiency for all of them. ďż˝

But it vastly increases reliability.

You can always limp around on 3 motors.

Not allways; it depends on the failure mode.


--
Jim Pennino

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