Battery based electric vehicles of today and tomorrow.

[Grumpycat]

Why are wheel-mounted motors a bad idea?

”unstrung unsprung mass” is the buzzword. The more your wheels weigh the harder they hit bumps. Also the road impacts must be borne by the hub centric motor. A driveshaft is a cheap simple means of reducing unstrung unsprung mass, increasing reliability, improving ride.

The hot setup these days is to mount rear brakes inboard, between differential and halfshaft to wheel.

Edit: darn predictive speller.

 

[MossRoad]

Why are wheel-mounted motors a bad idea?

Don't know if its a bad idea or not, but there's sprung and un-sprung weight. I learned about this when I ran my street bike hard and wanted to improve performance AND handling.

Anything that rides above the suspension is sprung weight (it rides on the springs).
Anything that rides below the suspension is un-sprung weight (it doesn't ride on the springs).

The way I understand it is that you want the suspension to be able to keep your tires in contact with the road as much as possible. The heavier the un-sprung weight (tires, rims, rotors, brake components, wheel motors, etc.), the harder the suspension has to work to keep that weight pushed down against the road.

Make sense?

 

[MossRoad]

”unstrung mass” is the buzzword. The more your wheels weigh the harder they hit bumps. Also the road impacts must be borne by the hub centric motor. A driveshaft is a cheap simple means of reducing unstrung mass, increasing reliability, improving ride.

The hot setup these days is to mount rear brakes inboard, between differential and halfshaft to wheel.

I think it's un-sprung, not unstrung, but you have the thought process correct.

 

[goeduck]

Will there be Old EV Car Shows? Oohing and aweing at those electric motors . This sure will change that slice of Americana, there is nothing really like looking under the hood at an Old Car Show to many of us. Oh well, there is still paint and upholstery.

 

[MossRoad]

Will there be Old EV Car Shows? ....

Apparently, yes!

 

[goeduck]

Apparently, yes!

Oh man, look at those Batteries!! Oh well, there is still paint and upholstery !!

 

[airbiscuit]

 

[Grumpycat]

Will there be Old EV Car Shows? Oohing and aweing at those electric motors . This sure will change that slice of Americana, there is nothing really like looking under the hood at an Old Car Show to many of us. Oh well, there is still paint and upholstery.

This is what I have under my Tesla Model S hood ("frunk" in Teslaology):

 

[SylvainG]

Oh! I should do that when I receive mine LOL

 

[txdon]

Don't know if its a bad idea or not, but there's sprung and un-sprung weight. I learned about this when I ran my street bike hard and wanted to improve performance AND handling.

Anything that rides above the suspension is sprung weight (it rides on the springs).
Anything that rides below the suspension is un-sprung weight (it doesn't ride on the springs).

The way I understand it is that you want the suspension to be able to keep your tires in contact with the road as much as possible. The heavier the un-sprung weight (tires, rims, rotors, brake components, wheel motors, etc.), the harder the suspension has to work to keep that weight pushed down against the road.

Make sense?

Yes Thanks.

Here is an article that goes into detail on the extra unsprung mass of the wheel mounted motors in an EV.

"Lotus found that the impact of increased unsprung mass, though noticeable to a trained driver, was really not all that significant."

StackPath

 

[Jstpssng]

This is what I have under my Tesla Model S hood ("frunk" in Teslaology):

View attachment 712409

Anybody who doesn't smile at this really needs to get their funnybone checked.

 

[Gale Hawkins]

A Decade Of Wind, Solar, & Nuclear In China Shows Clear Scalability Winners

As we discuss how to power the EV revolution the above article caught my attention since China is the largest car market and build the most EVs and are short on power generation.

 

[Gale Hawkins]

BYD unveils two electric trucks

Sounds like Warren Buffett made a good call on China heavy EV trucks. I see they come with the fire resistant batteries too.

 

[Larry Caldwell]

Acquired by Mercedes-Benz, YASA's revolutionary electric motor is set for big things | TechCrunch

Back in July, YASA (formerly Yokeless And Segmented Armature), a British electric motor startup with a revolutionary "axial-flux" motor, was acquired by

techcrunch.com

This sounds like it could make a good wheel mounted motor. A doubling of the torque sounds positive.

For a performance car, this is the way to do it. Four wheels, four motors, four sets of traction control sensors and controllers.

 

[goeduck]

When modern EVs were first talked about a number of years ago I always thought they would have a motor per drive wheel. It would seem to me that all of the slip/traction/AWD/cornering/eco/etc. functions would be easier done purely by wire. It did not dawn on me that there may still be one motor.

 

[Larry Caldwell]

Yes Thanks.

Here is an article that goes into detail on the extra unsprung mass of the wheel mounted motors in an EV.

"Lotus found that the impact of increased unsprung mass, though noticeable to a trained driver, was really not all that significant."

StackPath

I suspect the sprung mass of a large battery will do a lot to keep the car on the road.

 

[Frankenkubota]

”unstrung unsprung mass” is the buzzword. The more your wheels weigh the harder they hit bumps. Also the road impacts must be borne by the hub centric motor. A driveshaft is a cheap simple means of reducing unstrung unsprung mass, increasing reliability, improving ride.

The hot setup these days is to mount rear brakes inboard, between differential and halfshaft to wheel.

Edit: darn predictive speller.

my 66 e type had inboard rear disc brakes. supposedly you could access the rear break pads from above, thru the floor.

not

end of the day, easier to drop the whole rear end.

i thought they were cool but in the end, PITA.

 

[Jstpssng]

When modern EVs were first talked about a number of years ago I always thought they would have a motor per drive wheel. It would seem to me that all of the slip/traction/AWD/cornering/eco/etc. functions would be easier done purely by wire. It did not dawn on me that there may still be one motor.

Some time ago I watched a show on Discovery about experimental military Hummers powered by lithium batteries. They had a motor on each wheel as you say, and by running each pair in opposite directions they could pivot it in one spot.

 

[Gale Hawkins]

How Long Can OEMs Hold on Onto Their ICE Operations?

Merging just the North American powertrain units of GM, Ford and Stellantis would eliminate duplication and slash costs dramatically.

www.wardsauto.com

OEMs moving to EVs can make for strange bedfellows.

 

[Gale Hawkins]

SEA launches new electric truck small enough for any driver

I am starting to think small EV trucks may become a strong EV market market place for local use service and delivery needs.