Are there any LARGE BLDC motors?

[rsisson]

I am THINKING about a real-car EV conversion. Getting a small lightweight coup with a manual transmission and converting it to electric.

All of the "Small" conversions I have seen use a straight DC motor with a PWM controller.

The popular motors are the Warps, ADCs, and such.

QUESTION: Are there any BLDC type motors in the 18-40Hp range?

I have seen large AC motors, but they are big and expensive, and much higher voltage. I am thinking that a 144V BLDC motor would be pretty efficient, easy to control, and have many of the advantages of an AC Motor, but much simpler and at lower voltages.

Thoughts?

 

[pwbset]

I've often thought how cool would it be to get a little VW bug or Subaru Justy or similar tiny car... strip out all unnecessary weight and slap an overvolted/amped 5305 in each wheel. You'd get to 20-30hp* easy. Powered by a bunch of Milwaukee toolpacks at like 3s20p ($6,000 at current prices :lol: ) 84v52ah with a 100amp controller... you'd probably get like 35-40mph and 15-20 miles or so at like 250-300wh/mi*.Too bad you can't wrap a car tire around a 5305. Ha! Plus you'd need a burly controller that could account for differential wheel/motor speeds etc. etc. :lol:

* - numbers likely way off... just musing.

 

[ebinary]

I am THINKING about a real-car EV conversion. Getting a small lightweight coup with a manual transmission and converting it to electric.

All of the "Small" conversions I have seen use a straight DC motor with a PWM controller.

The popular motors are the Warps, ADCs, and such.

QUESTION: Are there any BLDC type motors in the 18-40Hp range?

I have seen large AC motors, but they are big and expensive, and much higher voltage. I am thinking that a 144V BLDC motor would be pretty efficient, easy to control, and have many of the advantages of an AC Motor, but much simpler and at lower voltages.

Thoughts?

I recently read about a guy who made an 5th eWheel out of a Lynch motor and was able to drive his car on the flat up to 30mph (and help with acceleration). Google for eWheel Insight.

Eric

 

[rsisson]

Kelly makes the Controller (120V 120A or 14KW, 28KW Peak) for such a motor....

http://www.kellycontroller.com/mot/Brushless-DC-Motor-Controller.html

So far I have only found ONE large Motor...

http://www.made-in-china.com/showroom/szunitemotor/product-detailpMVxlSjLCukc/China-BLDC-Car-Motor-15KW.html

There have to be more like this, maybe even a non-Chinese one ?

 

[pwbset]

They apparently make a 45kW one also.

http://www.made-in-china.com/showroom/szunitemotor/product-detailUekxcwOurPWv/China-45KW-Brushless-Vehicle-Motor.html

 

[rsisson]

Yowsa....

But at 300+ Volts I don't think so...

I was going to try to stay around 120V...

 

[RA]

Not in production yet... coming soon

48v 1000amp built-in controller
evaira.com/Propulsion.html

"Evaira propulsion engineers are currently working on an advanced brushless DC (BLDC) traction motor. The motor operates from a very low voltage, <50V... ...This safety motor design is also based on the use of small building blocks, or motor slices with integrated controllers, that can be adjacently stacked on a common shaft. The motors, which are flat discs in shape, have no protrusions or accesses along the flat sides, are designed to work in parallel in order to collectively increase power and torque. The size of the slices has been carefully selected to attain a balanced set of performance characteristics. One motor slice, with over 50kW peak and 15kW continuous power and over 50 ft-lb of torque..."

 

[pwbset]

Not in production yet... coming soon

Oooooh... 50v40ah LiMag batt (2kWhrs ) that does 120A continuous and weighs 38lbs @ 15.0"L x 6.7” W x 6.6” H.

*drool* I think I just spineled all over myself.

http://evaira.com/pdf/ES198L.pdf

 

[dequinox]

I was at first shocked to learn that the Impulse, warp, and ADC motors were all brushed. I can't really believe there isn't a market for large diameter/power BLDC motors yet. So I went on a little search on globalspec and found that there are a few companies who will build motors to your specifications...I'm sure for a pretty penny. Among them was this company, which seems to have some options for automotive-specific applications. http://www.ebmpapst-automotive.us/en/

I will continue my hunt, because I'm not really that enthused about building an Ecar until I know I can get a motor that is brushless.

 

[liveforphysics]

Its not the motor that is the problem.

Its the controller needing to be 6x the size, and more than 6x the cost for the same power level.

 

[nwhm20]

These guys

http://www.gravitron.co.uk/ElectricMotors/index.htm

And also these guys

http://www.oxfordyasamotors.com/

who make probably the most advanced dc brushless motor yet IMHO

 

[TylerDurden]

http://www.yuneec.co.uk/PowerMotor.html

http://www.uqm.com/propulsion_specs.php

 

[Arlo1]

There is lots volvo, bmw, porche and many more have in wheel motors for their hybrids ect. and see this thread. http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=16728

 

[Doctorbass]

For the 30-45hp range i know that it exist some High performance AC golf kart motor likle the AC-15 or more


http://www.hpevs.com/

Doc

 

[Malcolm]

I thought this was interesting from the Oxford Yasa site: http://www.oxfordyasamotors.com/lightweight-electric-motors
"Oxford Yasa Motors worked with engineering firm Delta Motorsport over the past eight months on a new lightweight motor. Woolmer said the group found the best way to reduce the weight was to take out the gearbox. The new direct-drive motor weighs 23kg, which he admits is slightly more than the LIFEcar motor, but it has a peak torque of 500 Newton-metres."

They've obviously come to the conclusion that the benefits of adding a gearbox aren't worth the weight penalty – that's the beauty of having 500 Nm of torque to play with

 

[nwhm20]

I thought this was interesting from the Oxford Yasa site: http://www.oxfordyasamotors.com/lightweight-electric-motors
"Oxford Yasa Motors worked with engineering firm Delta Motorsport over the past eight months on a new lightweight motor. Woolmer said the group found the best way to reduce the weight was to take out the gearbox. The new direct-drive motor weighs 23kg, which he admits is slightly more than the LIFEcar motor, but it has a peak torque of 500 Newton-metres."

They've obviously come to the conclusion that the benefits of adding a gearbox aren't worth the weight penalty – that's the beauty of having 500 Nm of torque to play with

Yeh that yasa motor looks incredible, there's quite a few technical papers out there on it which are very interesting. I'll try and find a link to one.

 

[liveforphysics]

500nm = 367ft-lbs of torque.

You're going to need some gearing for anything but a motorcycle (and it's going to want a chain-drive anyhow).

Even a humble base model Honda Civic or Toyota Corolla apply roughly ~1,800-2,200ft-lbs to the wheels when starting in first gear, and it certianly doesn't seem like anything to write home about. Acceptable hill climbing acceleration at best. Going to 1 of these motors would mean roughly 1/5th the torque of a typical economy car. Even putting 4 of them in the car, 1 per wheel, still gives you less torque at the wheels than a typical economy car, and you've got a very good chance of ending up heavier as well (if it's got a battery sized for decent range).

 

[Malcolm]

Yes, it's one motor per wheel, and you know as well as I do that you're comparing apples to pears

Yes, a mid-range Honda Civic could theoretically deliver 1800 ft lbs to the wheels in first gear, but only if you treat it like you stole it and drop the clutch at 4000+ revs. The driver of the electric car on the other hand just floors the go pedal. It's academic anyway as you're unlikely to be able to put all that torque through the wheels without breaking traction.

I was just trying to make the point that in certain situations it makes more sense to add more motor than to add a gearbox.

 

[Arlo1]

Its very cool but Im with luke! 367 ft/lbs tourque is nothing!
Lets do some math
I can launch my bmx at over 150 amps and 96 volts reading on my CA as I pass 10 mi/h
So with a 21 inch od wheel thats 900 feet per minute roughly and every rev of the wheel is 5.5 feet roughly so that would mean the wheel at 10 mi/h spins 163 rpm
150 amps x 96 volts = 14400 watts which = 14400/746 = 19.3 hp HP x 5252 / rpm = torque 19.3 x 5252 / 163 = 621 ft/lb torque! Now we all now its not that efficent so say even 50% efficent would be 310.5 ft/lb at 10 mph!

 

[liveforphysics]

Yes, it's one motor per wheel, and you know as well as I do that you're comparing apples to pears

Yes, a mid-range Honda Civic could theoretically deliver 1800 ft lbs to the wheels in first gear, but only if you treat it like you stole it and drop the clutch at 4000+ revs. The driver of the electric car on the other hand just floors the go pedal. It's academic anyway as you're unlikely to be able to put all that torque through the wheels without breaking traction.

I was just trying to make the point that in certain situations it makes more sense to add more motor than to add a gearbox.

I've got to disagree my friend. A typical Civic/corolla/focus/caviler/escort/sentra all do over 1,800ft-lbs to the wheels on an everyday driving around basis, auto and manual tranny alike. If you're over about 50% throttle in the mid-range RPMs in first gear with any of those cars, you're laying a boat load of torque to the wheels. This is a very common condition when doing normal daily driving, particularly in hilly areas.

Remember, a typical 1st gear ratio is 3.2:1, and a typical final drive around 4.25:1. This means when you take a typical midrange partial throttle torque value for these cars at say 130ft-lbs, you easily end up at 1,800ft-lbs at the wheels, and this isn't some flywheel inertia shock load or something, this is like grandma chugging home from the grocery store type conditions.

 

[liveforphysics]

Its very cool but Im with luke! 367 ft/lbs tourque is nothing!
Lets do some math
I can launch my bmx at over 150 amps and 96 volts reading on my CA as I pass 10 mi/h
So with a 21 inch od wheel thats 900 feet per minute roughly and every rev of the wheel is 5.5 feet roughty so that would meen the wheel at 10 mi/h spins 163 rpm
150 amps x 96 volts = 14400 watts which = 14400/746 = 19.3 hp HP x 5252 / rpm = torque 19.3 x 5252 / 163 = 621 ft/lb torque! Now we all now its not that efficent so say even 50% efficent would be 310.5 ft/lb at 10 mph!

Except you're below 10% efficiency at 10mph and 14kw, but you've definitely got a point.

 

[Arlo1]

Its very cool but Im with luke! 367 ft/lbs tourque is nothing!
Lets do some math
I can launch my bmx at over 150 amps and 96 volts reading on my CA as I pass 10 mi/h
So with a 21 inch od wheel thats 900 feet per minute roughly and every rev of the wheel is 5.5 feet roughty so that would meen the wheel at 10 mi/h spins 163 rpm
150 amps x 96 volts = 14400 watts which = 14400/746 = 19.3 hp HP x 5252 / rpm = torque 19.3 x 5252 / 163 = 621 ft/lb torque! Now we all now its not that efficent so say even 50% efficent would be 310.5 ft/lb at 10 mph!

Except you're below 10% efficiency at 10mph and 14kw, but you've definitely got a point.

Haha I didnt know where to guess the efficiency at lol But it is a bmx! lol I do know I have had 160-180 lb riders leaning over the handle bars and cant keep the front on the ground!

 

[Malcolm]

I'm not sure what you're trying to say Luke. The Yasa motor weighs 23 kg and has a peak torque of 360 ft lbs. A mid-range Civic engine weighs about 130 kg(?) and has a peak torque of 130 ft lbs. You can multiply the torque of both of them as much as you want, but for a given ratio that little Yasa motor will will still produce almost three time as much torque for a fifth of the weight. The point is that these motors have such a high torque density that, instead of adding a gearbox, it can make more sense to add more motors to get your desired torque, whatever that happens to be.

 

[nwhm20]

Luke you must be joking?! 500Nm in a motorbike is sh*t loads, a CBR1000 has about 135Nm (100ftlb)!

Yeh for a car you could use two...this link shows them drifting a westfield with a Yasa motor in each wheel, given it's a light car but that's without any gearing...with gearing you would be getting ridiculous amounts of torque to the ground:

http://www.youtube.com/watch?v=OJmUv3P88O4

*yes the cbr will have gearing between the engine and wheel but with 500Nm from standstill you wouldn't need multiple gears, this is the point Malcolm was trying to make (i think).

 

[Arlo1]

Luke you must be joking?! 500Nm in a motorbike is sh*t loads, a CBR1000 has about 135Nm (100ftlb)!

Yeh for a car you could use two...this link shows them drifting a westfield with a Yasa motor in each wheel, given it's a light car but that's without any gearing...with gearing you would be getting ridiculous amounts of torque to the ground:

http://www.youtube.com/watch?v=OJmUv3P88O4

*yes the cbr will have gearing between the engine and wheel but with 500Nm from standstill you wouldn't need multiple gears, this is the point Malcolm was trying to make (i think).

So OEM gearing is 42 x 16 for the sprokets on a 06-09 crb 1000 thats a ratio of 2.625
And for first gear inside the tranny the gearing is 33 x 13 which is a ratio of 2.538
Giving you a overall ratio of 6.66 So in first gear you have 6.66 times the tourque of the engine avalible! So if it has 100ft/lb in first it has 666 ft/lb at the wheel! Now there is some small losses ect but still its all about gearing and thats what lukes trying to say!
Now that I look at it I need to make my bmx 100 percent eficent