How's this Haoren hub motor look from technical standpoint?

[John in CR]

Here's what I thought was the significant info along with pics. Let me know what else would be of value.

Rated speed 900rpm but it does about 700rpms with 240lb me and a 20" diameter tire (about 42mph)
Magnet width 40mm
46 magnets with 9mm thick iron ring housing them
51 stator poles with 80 laminations
windings unknown- see pic
200mm stator diameter
axle diameter 22mm at the stator
axle diameter 20mm at the bearings
axle dia wire side 16mm w/ 12mm flats
axle dia brake side 14mm w/ 12mm flats
heavy duty no slip nuts plus spacers and 2 torque bars
sealed bearing plus additional exterior rubber bushing to keep water out.
controller 60V 30A continuous with 15 unknown fets
All entries to controller sealed with silicone, including all screw heads and in addition to the rubber grommets for wires
DC/DC converter 36-60V to 12V10A
Phase wires are 12ga and the wire harness isn't a sleeve. It's 10mm thick stiff rubber formed around the wires.
Phase and power wires bolt together in ceramic housing.
30lbs for entire wheel assembly including steel motorcycle rim and tire.

I've only seen 10 different hub motors and none have had nearly the attention to detail. It's heavy, so not for everyone. It may be too fast for most, since it pushes 240lb me + 80lb bike around at 40+mph using a 20" or 23" diameter tire. It struggles on the hills and that's the only time it gets more than slightly warm to the touch. In fact the controller is always hotter than the motor.

I was expecting a lot more copper than I found when I opened it up. I'm hoping someone can look at the info and pics to advise on how much I can push the performance. I'd really like it to maintain some decent speed up the 12% grades I deal with daily, so it doesn't bog down to a creap with pedalling, which causes rapid heat buildup. For someone living in a flat area, and needs a fast street bike for commuting or errands, it seems ideal as long as you don't want a bike you need to pick up all the time, because it's a heavyweight. I'm finding out minimum quantities needed for them to do a run with side covers to make it more bike friendly.

 

[John in CR]

Some more pics. Let me know what else you want to see or see closer, while I have this one opened up. Please excuse the brushed up covers. I'm painting them to match my bikes.

 

[John in CR]

Essentially I've found a factory that puts out what seems to me to be a high quality motor that is looking to expand to international sales, so they seem interested to work with me on modifying the motor of which they are quite proud for use in a different manner than designed. If it makes sense to your guys too, then I'll probably go forward and be able to offer these things incredibly cheap. The prices I see disgust me, because I know the prices paid, and this would be a case of more for less, for something we can call some of the design shots.

Also, I think the controller might be based on an Infineon board. If so, maybe some of you guru's could come up with some improvements, like regen or getting the operating temp lower, making the LVC variable, program-ability, etc. In which case, I'm sure I can swing a nice batch of free motors.

John

 

[spike]

I'd be happy to stress test one and report back. I'd really like to try a fast, quiet DD rear hub and a front geared hub working together.
Only trouble is I'm in Aus so getting the motor here cheap might be a sticking point. Let me know if you want me as a tester anyway.

 

[John in CR]

I'm sorry Spike, I guess my wording was poor. I've been doing plenty of stress testing of a number of motors myself, and this one is the cream of the crop so far. I meant "this motor seems good to me, but what do the experts think? Is it worth pursuing? My only real issue is the weight, and then I open it up and this 9mm ring of iron around the magnets is the heavy part, not the copper. I have no idea if that's good or bad. It seems like lots of poles and magnets, but again is that good or bad? They seem to have taken as little in the form of magnet material and copper, then gotten quite a bit of hubmotor performance out of it, and they paid attention to the little details along the way.

John

 

[fechter]

I think it looks pretty good.

It appears to be around the same size as a Xlyte 400 series. I like the way the windings only go around one pole (salient wound) vs. the Crystalyte's 3 poles. This theoretically reduces copper losses in the ends of the windings.

I like the sheet metal spider in the center of the stator too. Saves weight.

As far as mods go, the standard stuff might apply. Heavier phase wires, cooling?, stronger magnets.

 

[John in CR]

I wasn't really thinking about modding the motor, other than to make them bike motors and cut the brake drum off to narrow it and drop a bit of weight. What about that heavy ass 9mm thick iron ring. Does that thickness add much benefit, because it's the majority of the weight?

You mentioned magnets, do I have to maintain the same number, or does it just have to be an even number. Does that ratio of poles to magnet have to be certain ratios. I actually have some N50 neo's that are thicker too, so much stronger, and 34 will fit nicely. I'd have to machine out some of that heavy ring, so I like the idea of losing some weight. How much could improving the magnets help performance, and in what way would it? I want more torque.

The only time the motor ever gets more than slightly warm is after bogging down to very low speed on hills. Based on those windings, which I'm guessing is 2 turns, how hard to you think I can push this thing?

As far as cooling, this thing would be a great candidate. There's tons of open space inside those covers all the way up to the stator, and the axle has plenty of room, even just using the existing notch for the wire harness.

John

 

[voicecoils]

So, it's on a motorcycle-type rim and has a drum brake. Perhaps designed for a pedal-cab or something?

Is the axle spacing at all suitable for a bicycle? Standard MTBs have 135mm spacing, modern road bikes are 130mm, track bikes are 120mm, DH racing bikes are 150mm these days (but most use a thru-axle not a standard dropout).

What is the total motor weight?
Can it be used without the drum brake?

Interesting find, I'll sit back and let others chime in with opinions on the electrical & mechanical design of the motor.

 

[John in CR]

So, it's on a motorcycle-type rim and has a drum brake. Perhaps designed for a pedal-cab or something?

Is the axle spacing at all suitable for a bicycle? Standard MTBs have 135mm spacing, modern road bikes are 130mm, track bikes are 120mm, DH racing bikes are 150mm these days (but most use a thru-axle not a standard dropout).

What is the total motor weight?
Can it be used without the drum brake?

Interesting find, I'll sit back and let others chime in with opinions on the electrical & mechanical design of the motor.

No, not a pedal cab. It's a speed wind, not torque, 70kph with 200lb electric motorcycles. Unfortunately none are those with pedals. The motor itself is 12kg.

I stretched one steel frame out to the 210mm needed with the drum brake. Another fit the 210mm after extending and stretching out the swingarms on a 24" steel dual suspension MTB. As is they require bike mods, but with a different side cover to get rid of the drum, bike rears will be easy. It's nice to have a real brake, but a disk could make it so much narrower. Bikes really should be modded for these speeds anyway. I'm going to mod one motor down to normal bike dimensions including disk brake to put on the front of my kid and grocery hauling speedster to make it 2wd, so hopefully pedaling uphill becomes optional. I just need to get my bikes a bit prettier, and I'll start a thread of my builds.

John

 

[docnjoj]

Hey John in CR! Can U get them without the brake? My trike only uses 2 front discs and they can stand it on its nose! As you can imagine now after my accident I really dont want anything that may lock up a rear wheel again! Also those shoes look like they weigh a bit too!
otherDoc

 

[fechter]

A 9mm magnet backing does sound excessive. I think you could make it quite a bit thinner, like 4mm. As you make it thinner, at some point, the magnetic flux in the backing will saturate and start reducing the flux in the motor. You can tell this is happening if the outside of the ring strongly attracts a piece of steel. When the flux is reduced, the torque will drop and the no-load rpm will increase. You could test it now with a paperclip. The motor must be assembled for this test. If a paperclip won't stick to the outside of the ring, it's thicker than it needs to be.

You could thin it beyond saturation and compensate by using stronger magnets. The number of magnets needs to remain the same to keep the hall phasing correct. Using stronger magnets will give you more torque and less speed. It will also improve the efficiency under high load, low rpm conditions at the expense of efficiency under light load, high rpm condtions.

See if you can figure out if the windings are delta or wye connected. In a delta, two winding ends go to each phase wire. In a wye, one winding end goes to each phase wire and there is a junction for the 3 other ends. If it is delta connected, changing to a wye would give more torque/amp and less rpm/volt. I think you'd have to re-phase the hall sensors to make this work too.

 

[John in CR]

Hey John in CR! Can U get them without the brake? My trike only uses 2 front discs and they can stand it on its nose! As you can imagine now after my accident I really dont want anything that may lock up a rear wheel again! Also those shoes look like they weigh a bit too!
otherDoc

I'm just waiting for minimum order quantities to make a modified motor covers to make it bike friendly. My Chinese friend is starting to come around to the concept that crazy people outside of China really do want 15000-2kw motors on their bikes. Also, don't you have hills? I need to come up with a hill solution before I'd be comfortable recommending it to anyone not a "flatlander", unless a 15-16" diameter tire works for you, or 20" is okay and hills aren't longer than a couple hundred yards or less than 10% grade. I need to change my GPS to fine resolution and find out exactly what the grade is on my 2 primary route hills that the motor struggles up. I just checked my GPS route profiles, and I'm seeing well over 20% grades. Maybe it's better than I thought, since the other day I did pass right by a guy who was walking his bike up the hill, but I was adding about the maximum sitting down pedal assist. If the hill was twice as long I'd take another route, since I feel a significant performance loss due to hot windings after reaching the top of that 200M stretch.

Regarding the weight, I'm going to put one of my 5 motors on a weight loss and width reduction program and see what I get. I checked and the magnet retaining ring is definitely not fully saturated so there's significant room for weight loss there, plus a couple of pounds in the brake assembly and drum, but going from 12kg to 8-10kg probably won't make much difference in feel with a rear drive. Curb and stair jumping at speed with a downhill type frame shouldn't be with a hub motor anyway, IMHO. I only feel that 30lb wheel assembly when I pick it up to put in my van or hit a speed bump at speed with my dual suspension bike, which has limited travel anyway. Sure I feel the weight manhandling it in tight quarters while off of the bike, but it's not strenuous in the least and a non-issue, just exercise. It's definitely a man's motor though, if the bike needs to be picked up. In your case, with a tadpole, the weight may actually be advantageous to keeping the rear firmly down.

John

 

[John in CR]

Thanks Fechter,

A WYE vs Delta config might be easy, but if I can source identically sized N50 magnets that may be worth a try and not too expensive since these are pretty small and thin. I might even be able to just special order some with stronger magnets, since the darn thing goes faster than regular bikes need to go. On all of mine, I'm modifying for longer and lower than a normal bike. Upright bikes and 40mph+ is not a thrill I like.

John

 

[fechter]

If you removed the stock magnets and machined the backing ring down to 4-5mm, you would have room for thicker magnets :wink:

The spacing between magnets is not so crictical. It would work if there was a small gap between adjacent magnets as long as they are evenly spaced.

Cutting magnets sucks. Been there, done that.

 

[docnjoj]

[quote In your case, with a tadpole, the weight may actually be advantageous to keeping the rear firmly down.

John[/quote]
You got that right! But I too have a suspension on the rear that has 4-5 inchex of travel at the wheel! I've followed the master (Julian Edgar) and it really works pretty well. It hates unsprung weight and loves the Bafang! Thanks John!
David

 

[John in CR]

If you removed the stock magnets and machined the backing ring down to 4-5mm, you would have room for thicker magnets :wink:

The spacing between magnets is not so crictical. It would work if there was a small gap between adjacent magnets as long as they are evenly spaced.

Cutting magnets sucks. Been there, done that.

Yes, thicker was a thought, but I looked and the screw holes for the covers are too close to that inner edge to accomplish much. Instead I'm thinking to just try to find a piece of pipe the correct diameter and thickness and fab a new ring.

I heard you can't even drill holes in these Neo's, much less cut one, and they can be dangerous when they shatter, so that thought hadn't crossed my mind, but thanks for the warning anyway.

John

 

[docnjoj]

From my R/c electric glider days I remember that they mould the Neos rather than cut or shape. Also both Neodyme and Boron dust are active lung carcinogens. Be careful out there John!
other'doc