Geared hub

[ngocthach1130]

Hmm just recently there was an announcement on ebike.ca stocking up on new motor. I'm wondering if there are any places that sell those Puma motor for the U.S market. Everyone is raving about them but i can't find any place that sell them.

Another problem is how people complain of the noise these motor make. I'm wondering if we could come up with after market solution for these hub. I'm guessing the noise come from the gear and why won't these company use offset gear with diagonal teeth. Car uses them so the gear engage gradually and reduce noise as well as wear and tear. Couldn't we come up with something similar for these hub motor?

 

[vanilla ice]

Never said anything, but since I joined ES I've been wondering the same about the cut on the gears...

 

[fechter]

I think it would be pretty challenging to come up with an aftermarket gear setup. I suspect the pinion gear on the motor shaft and the ring gear might be difficult to replace.

Using helical mesh gears would really cut down on the noise and probably last longer, but it would introduce a significant amount of axial thrust on the gears. I'm not sure if the existing supporting structure would be strong enough to prevent the gears from deflecting under load.

Of course, if you designed it this way from the beginning, all the axial loads could be handled by proper bearings.

*** manufacturers- are you LISTENING? ***

It would be much better if they just built stuff right in the first place so we don't have to re-engineer the whole thing.

If you used twin helical "herringbone" gears, you could eliminate the axial loads. I think they are quite a bit more expensive than normal gears.

 

[ngocthach1130]

Yeah i figured the V formation of the teeth would be harder to cut than the helical formation. Helical shouldn't be too hard. I've thought about the thrust load on the enclosure. I'm thinking since these hub motor do not have brushes sitting on the side motor cover we could replace that as well and add on a slightly bulgier cover which could house conical bearing which would take the thrust better. On howitworks.com have great write up on bearing configuration. The roller thrust bearing they have look like it shouldn't add much width to the whole enclosure.

 

[docnjoj]

Yes to axial loading! I use Bretts P2A and after 2.5 years of regular use I needed to open up the case and shim axially. I ride a trike and corner hard, so it came as no surprise! A 1.5 mm shim washer solved the problem(grinding against the case) This motor has helical gears, and is a great value!
Doc

 

[Jozzer]

Contact Mark @ teamhybrid for info on Puma in the USA, I believe he has distribution rights there too.
The puma is very quiet really, in fact it sounds quieter than an X5! Not noticed anyone complaining about the noise either??

 

[ngocthach1130]

Hmmm i'll give that a thought. Although i'm concern about longevity where upgrading in helical gear will not only reduce noise but also wear and tear. Gear connect gradually and not bashing from one teeth on another.

Here's the thing i have problem with. Gearless hub hold you back on steep hill where you could def go faster if you just not adding any acceleration. So to keep up with the momentum i have to crank the motor to max which draw precious amperage. With these geared hub there would be some freewheeling action but they are prone to wear and tear from teh speed we throw at it. So i'm looking for ways to reduce wear and tear.

On this forum people reporting newer version of puma have metal gear but with slightly higher noise. You also have to grease it unlike self lubricating nylon gear.

Any of you own your own machine shop and willing to work up some working prototype?

 

[recumbent]

i'm concern about longevity where upgrading in helical gear will not only reduce noise but also wear and tear. Gear connect gradually and not bashing from one teeth on another.

Just purchase a spare set of nylon gears when you get the motor, if your so concerned about wear. You win in every way, and cost a lot less than redesigning the system to accomodate your helical gear theory which may not be as easy as you think.

:? Oh, Straight cut gears don't "bash" they mesh beautifully together, almost as one.

 

[fechter]

I think the only downside to straight cut gears is the noise.
I agree with Jozzer that the Puma motor is as quiet as an X5 (perhaps quieter). You could probably make it even quieter by feeding the motor with a more rounded waveform. The only controllers that do this are very expensive (until I make my own). I think the noise from the actual motor is more than from the gears.

The Heinzmann motors are the noisy ones.

 

[Jozzer]

The motors from Mark will come with Nylon gears unless you ask for a metal geared one I understand. I havn't tried the metal gears yet, I will do when the shipment comes in...

 

[Tom]

The ezee at ebikes.ca bundled with 10ah battery:

I also noticed EV Tech (texaselectricbikes.com) has a newer looking Puma? on their website (with or without 15ah battery).

Anyone know if these are the same as the Pumas that teamhybrid sells?

 

[Jozzer]

The last is the BMC. It is very similar to the puma, but doesn't have all the refining changes Mark had made to the design.

Mark will ship from the UK, customers from the USA dont have to pay the UK tax, which will work out about the same as the postage I believe.

 

[deecanio]

wonder where this myth comes from that pumas are noisy? mine is sweet as and the tyre noise is louder than the motor?
I'll be joining you jozzer on the new pumas when they are ready, im hoping for the 320rpm rear but i want a disk for sure - those baby's should be bang on nylon gears or not - i think Knoxie was looking into the metal gear replacements but to be honest i'd be happy enough to swap out the nylon ones to keep things nice and stealth
by the way steve i will be wanting your thoughts on a nice A123 pack at some point in the future too


cheers


D

 

[Jozzer]

Hiya Deec, been playing at 72v much? Metal gears will be optional from the factory after the next shipment, I believe at no extra cost. Also, Mark will have some metal gear kits for aftermarket fitting.
i'm quite happy with the 260rpm Puma tbh, I want the 320's so I can sell bikes with them at 48v with a decent top speed, rather than 60v+ (lots of 20" wheeled bikes to fit up here!) He's hoping for stock before xmas, hopefully any time now!

Why are you thinking of A123's deec? Arn't the lipo's working out for you? Ahh....I bet you want more current!

I think Teamhybrid is hoping to offer a new improved version of the point 1 packs soon too...

 

[deecanio]

hi mate

yes been very impressed with the a123 current output, although i do need to run my current lipos next summer.
Haven't looked at the bike since it's maiden voyage at 72v mate been mega busy with electricians,plumbers and plasterers every weekend and the bike is covered in dust at the mo
Really im just thinking of the next setup i'll go out and out downhill bike with an arse kicking setup, maybe give the DC1 to the wife!!! hehe might be a tad quick for her though - paralell them lipo's for her ;p
what you up to mate? it's a bit chilly to ride? interested in your bike builds - what base bike are you going to use?


Cheers


D

 

[Jozzer]

Hehe, Damn cold! Only riding going on is to and from the workshop for the moment. I've got a couple of KMX's and a schwin type chopper to fit up, but more fun still is a honda cr85. All stripped out ready to go, Perm 132 and a 72v300A controller on the way! But thats another story (which will follow in a thread with pics)
me looks out the window for springtime...

 

[deecanio]

hehe a cr85 eh??
now you got my attention i see a "zilla" controller comin!!
that will be awesome, i hope you have the freedom where you live to get a ride without hassle, a cr85 will get you noticed way more electric or not.
would be a super cool project though - are you looking for electric mx type performance?do battle with the blade

lookin forward to the posts and the warm again, brrrrrrr



cheers


D

 

[Jozzer]

Oh yeah, not for the street. 30hp ish should compete well with most things out there