Hybrid home conversion with rear hub motors

[Christ]

Originally Posted by MetroMPG

Almighty, did your forklifts also have a mechanical/friction seat brake? A drum on the motor's tailshaft? The one we bought to scavenge for the ForkenSwift had both plug braking and the safety/seat brake.

(And I had to steer it after removing the power steering pump [and everything else], while it was being winched onto the flatbed truck that took it away - that was a bit of wrestling with the wheel.)

Nope, just an e-stop button with a brake that was meant to keep it stationary.

If you tried to stop from speed, you'd most certainly smell the brakes... but you could use it to do so, that's why it was called an E-Stop.

[Clev]

Originally Posted by metromizer

The Poulsen drive hubs don't eliminate the OEM brakes

The Poulsen system also adds 38 pounds of unsprung weight to each wheel, while providing a 7 hp boost to each wheel. It also doesn't eliminate weight anywhere else. For the purposes of an all-electric wheel-motor car that we've been discussing, it's too low-power.

For the purposes of a hybrid pickup (the OP's question), I'd rather belt an eTek (28 pounds, 8 hp continuous, 15 hp peak for 2 minutes) to the crankshaft and use the mechanical advantage of the transmission to make the electric boost and regen more usable.

A Poulsen on one wheel would be cool for stop-and-go, if it produces enough power (can 7hp direct driven at 1:1 actually accelerate and decelerate the car enough to even keep up with stop-and-go, or do you still have to use the engine?)

[Christ]

Originally Posted by Clev

A Poulsen on one wheel would be cool for stop-and-go, if it produces enough power (can 7hp direct driven at 1:1 actually accelerate and decelerate the car enough to even keep up with stop-and-go, or do you still have to use the engine?)

Too many variables to say accurately, but I do know that most 3 and 4 cylinder engines make very little power at low RPM, where we normally drive them.

So, that said, it would be like accelerating from 1500 RPM in 4th gear constantly. (example) IOW, you leave the light normally, shift from first to 4th without accelerating past 1500RPM, then begin your acceleration.

For reference, give it a shot. Idle in fourth gear, record your speed, then accelerate to 30mph, timing your acceleration.

Once you've done that, drive normally to your 4th gear idle speed again, but in whatever gear you'd normally be in at this point (if you granny shift, 3rd on most cars) and accelerate to 30 the way you normally would. Time this acceleration as well.

This will give you a comparison between the two, and will give you INSIGHT (not a straight answer) as to whether you can drive stop and go easily with very low horsepower at 1:1 (helps to eliminate some variables).

[metromizer]

Originally Posted by blueflame

What about building hub motors that replace the rear rims on a FWD car?
...Batterys and controller in the rear and it could installed in half a day with little attention to existing components... Louvre screens on grill to keep engine warm?

Should reduce running costs....70mpg to 150mpg??

hey Clev, I took <the above OP> to mean his idea is to leave the original FWD w/ICE drivetrain in tact, and adding e-drive to the rear hubs similar to an e-scooter. I'm not reading all-electric drive in that. Maybe I'm mixing up my threads

[Clev]

Originally Posted by metromizer

hey Clev, I took <the above OP> to mean his idea is to leave the original FWD w/ICE drivetrain in tact, and adding e-drive to the rear hubs similar to an e-scooter. I'm not reading all-electric drive in that. Maybe I'm mixing up my threads

Yeah, sorry, the all-electric hub motor discussion was a bit of a threadjack, which is why I was trying to bring it back to the OP's question about rear hubs. :-)

[Frank Lee]

I like the concept of hub motors for the interior space efficiency and the lack of drivetrain losses.

I don't like the concept of hub motors because, as a former vehicle designer, I had the realization that I want the bits in vulnerable areas to be rugged, simple, cheap, and easy to service. I want the expensive bits to be enclosed in relative safety. Rims are out there as the second line of defense against major road impacts and they do get bent with some frequency. They are in a harsher environment as far as grit, moisture, vibration, etc. than your typical engine in an engine bay, even though it's only inches away. Rims are easy and relatively cheap to repair or replace. I can't imagine a hub motor that could be as light, cheap, and durable as a rim. For those reasons alone I would vote for having the motor in a more interior, protected location.

And there are other mundane practical matters to consider. Would the hub motor still use a conventional rim? If not, using a standard tire changer to service the tires could become an adventure.

[Christ]

What about the style of motor where it's a two piece wheel, and the armature is the inner (solid mounted) portion, and the "casing" is the outer (rotating portion).


The motor is built backwards so that the wiring can be attached to the inner portion which acts as an armature... essentially, reversing roles of the two main parts of the motor.

Put a rubber tire around that setup with ~40-60PSI.

[almightybmw]

Originally Posted by MetroMPG

Almighty, did your forklifts also have a mechanical/friction seat brake? A drum on the motor's tailshaft? The one we bought to scavenge for the ForkenSwift had both plug braking and the safety/seat brake.

(And I had to steer it after removing the power steering pump [and everything else], while it was being winched onto the flatbed truck that took it away - that was a bit of wrestling with the wheel.)

Nope. It was an on-off switch. I could do things more quickly by braking up to the place I'm stopping, but not stop, and jump ship early. I worked at a coke plant (sounds funny when I say it that way) so loading up pallets for shipments means lots of running around loading different products. I never hit anything and it never rolled more than a few feet, about the amount I needed it to. It saved me about 15-30 minutes of work by doing this, and when you have 30 pallets and 8 trucks to load, and you start work at 5pm, getting out at 1am instead of 2am or later, every minute saved is worth it.

Not sure if that description makes sense. Kind of a long description eh? The propane fork did have mechanical brakes, and it showed. Sucker hauled, won the drag races, but braking was twice that of the electrical lifts. Sucked having to rev the motor when using the hydrolics too. "hold brake, rev motor, operate levers" lame machine.

[Funny]

I sure hope that these: Michelin Prototype Hub motors are what you guys are discussing. I would love to get a pair of these in a 15" wheel and throw 'em onto the Lemon...

[blueflame]

Would rideability and enjoyability go against hub motors?

Slower accelleration, poor suspension performance and poor related steering through corners?

Would feel like lead in your shoes and your big stomach all gone.

I'm already barely hitting 60mph nowadays. Hanging it out thru a corner is the only fun I have nowadays (plus its a good hypermiling technique)

Or would a hubmotor used boringly to maintain speed (like on the freeway) rather than accellerate from slow(ICE does that) have benefits over axles.
Like inertia, kinda a pendulum wheel like a clock.

Hubless electric wheels must be expensive to build.

Would a geared electric motor give better performance than the single speed hub motor, mitigating drivetrain losses? Or are hub motors good to go thru speeds 0-100km/hr.

My single speed electric scooter (belt driven) groans at slow speeds and over revs at the top speed of 27km/hr...