2 Speed Xiongda hubmotor

It is a very old principle that is in use in a lot of applications since a very long time.
As the reversing of the rotation pushes the planetary gears into place, no extra mechanism is needed to change gears.
Simple and very reliable if the choice of materials is done well.
I got a 50 year old bike here that works exactly the same way and it works like the first day, without any maintenance at all, ever.
 
I find being able to roll backward a most useful feature, though I guess at a stop sign on an incline would be nice. No rolling backward is the only thing that's stopped me from doing a powerful RD rig.
 
Perhaps a freewheeling crankset could be employed to allow the Justin-style RD hub bike to roll backwards? Admittedly it adds another level of complexity to a system that hopes to simplify things, but...just a thought.

edit: (*slaps forehead) "D'oh!"
 
crossbreak said:
yep. i see. it has the backwards rolling issue too i guess? was the backwards rolling issue solved with any of these two speed motors?

The Xiongda rolls backwards OK in both gears when you're riding it, but sometimes, when I ride up the last bit to my house in low gear, I can't reverse it out the next day. I have to put it in high gear, power the motor, and then whether I leave it in high or switch back to low (after powering in low), i can reverse it out.
 
They're just about to change the controllers over to sine-wave. Any controller with a pair of wires for reversing the direction should work.
 
cwah said:
you mean reversing phase wiring? I don't know any controller that can do that

No, it's done by software. These controllers have two additional jumper wires. When they're connected, the motor runs in one direction, and when disconnected, it goes the other way. The wires go straight to the CPU as an input. The software in the CPU changes the timing sequence.
 
uhhh, those Xiongda 2-speed hub are big.
No chance to get mine married with a cannondale fatty for example, no matter with or without disk !

@ d8veh
Thanks for bringing this exceptional motor to our attention, very much appreciated !

Would like to see a version comming up that fits standard 100mm forks. No problem for me if diameter would become slightly bigger then.


 
panurge said:
crossbreak said:
isn't that almost the same what Justin patented as well?

http://www.google.st/patents/US20120302390

One difference, If I well remember, is that in Justin's design, the high speed is gearless, that's a big difference....

Yeah, in case people are wondering about this, our concept was to have what was mostly a direct drive motor (relatively large but silent with minimal moving parts), but which has the ability to switch into a high torque 2:1 gear reduction drive whenever there are steep hills encountered which otherwise bog down the direct drive hub. I think it's possible to pull this off with an overall hub weight of 5kg while maintaining a 27mm wide stator and magnet. We'd worked out a few relatively simple mechanical techniques to allow limited reverse rolling (like 1-2 revolutions) so that it wouldn't lock up right away when you rolled backwards, but one downside that I hadn't figured out was enabling regen in the forwards direct drive mode. So while you'd get the benefit of direct drive silence and simplicity, the intrinsic freewheeling prevents reverse torque transmission so you loose advantages of regen. And given that, I think having both forwards drives geared as Xiongda did is probably the better approach.

We don't have any plans of trying to commercialize a hub like this anymore. But I still fancy building up a full scale working prototype based on the 205mm direct drive motor series, cause it would still be kinda cool to see.

-Justin
 
justin_le said:
panurge said:
crossbreak said:
isn't that almost the same what Justin patented as well?
http://www.google.st/patents/US20120302390
One difference, If I well remember, is that in Justin's design, the high speed is gearless, that's a big difference....
.... our concept was to have what was mostly a direct drive motor (relatively large but silent with minimal moving parts), but which has the ability to switch into a high torque 2:1 gear reduction drive whenever there are steep hills encountered....
We don't have any plans of trying to commercialize a hub like this anymore....

9C-like motor with gear reduction?
Shut_up_and_take_my_money.png


:D
 
i think this is a very good plan.. using 2 speeds with high pole count...all you need to add is an automatic clutch that allows both ways of torque. that shouldn't be too hard to invent

We see pole counts of 36 to 54 in DD hubs. The MAC has 32.. so these world are not so far separated. I have to add here that even the 0.3mm lams geared motors have high loss due eddy current (which is the major drawbach of geared drive at high rpm).. so...

Why not use both reductions like 1:1 and 1:2 in one drive. must not be a hubdrive. but could be. we just need 2 clutches that are really 2-way to get regen as well...

sounds hard but doable.
 
crossbreak said:
i think this is a very good plan.. using 2 speeds with high pole count...all you need to add is an automatic clutch that allows both ways of torque. that shouldn't be too hard to invent

The problem with automatic clutches is that then the whole elegant shifting simplicity no longer applies. The fact that you can just reverse the motor direction to change gearing without any clutch or transmission box is what makes this 2-speed approach so compelling. Once you need clutches and stuff, then you might as well have a more conventional transmission.
 
endlessly_ending said:
uhhh, those Xiongda 2-speed hub are big.
No chance to get mine married with a cannondale fatty for example, no matter with or without disk !

@ d8veh
Thanks for bringing this exceptional motor to our attention, very much appreciated !

Would like to see a version comming up that fits standard 100mm forks. No problem for me if diameter would become slightly bigger then.



That's really bad luck. There was some discussion about that on the German forum. I've now two bikes with the rear motor. The first one was a cheap steel FS bike. I just jacked it wider until the motor fitted, but then had to dish the wheel quite a lot to get the rim central. The second one was a Rocky Mountain FS MTB. I jacked it much wider so that I could use spacers on the disc side to get the rim central without dishing. Two build threads here:

http://www.pedelecs.co.uk/forum/threads/rocky-mountain-conversion-with-xiongda-kit.17654/#post-218580
http://www.pedelecs.co.uk/forum/threads/xiongda-two-speed-motor.17219/
 
This drawing shows the front motor fitting into 100mm dropouts but 52.5 mm from a centreline, so that points to about 105 mm.
http://xiongdamotor.en.alibaba.com/product/1604877927-220560510/Double_Clutch_2_Speed_E_bike_Motor_with_Amazing_Torque_Electric_Bicycle_Motor_6_freewheel.html
Endlessly_Ending could you spread the forks at all (presuming they are solid) & maybe put a couple of spacer washers in. I had to do this with some of the early front hub motors (Tongxin & Golden HBM) One good point about front motors is that if you can get one in there is no dishing involved in the wheelbuld, thus easier to do as a DIY job.
most of my builds have been front motors for this reason. I do though have doubts about the supplied torque washers & think if ever I get one of these motors I would make some much beefier torque arms (for when the motor is in low gear) otherwise I could see the torque reaction splitting the dropouts in some cases. I have somewhere a bike with wide front solid forks (I was going to mount a SA hub in it & chain drive it from a remote motor, so will check all this out when I get time) I'm first considering some Ni Zn batts as the one I have for the Tongxin 10 A/h @ 1C max constant is not up to driving the xiongda. Another set of Lipo is beyond me just to run the motor (sigh)
 
Some forks have the the drop-outs inboard so that the inner face is parallel with the inner edge of the fork, which would solver the problem if you want to change the forks.
 
Hello guys

I'm just waiting for 2 of these motors to be delivered, one is for a 20" fatbike the other is for a 700c tourer project with a custom 7005 frame.
I'll try both the sine and the square controllers, with a pair of the possible displays.....

Indeed these 2speed motors are too wide (both the rear and the front versions). only the non disc versions can fit the standard 100/135mm.....

I asked for a slightly modified motor for the 700c, the standard disc/multispeed motor is 146mm, I asked XD to file and extend a bit the threads on the drive side, so that I can reach 137mm, obviously at that point, the space for a standard multispeed freewheel would be not enough, but with a longer nut I can get again the original 146mm dropout, and I'm anyway confident about to fit to the 137mm, with or without mods, one of the zillions freewheel units that are lost in the shop, ....
The 700c motor is wound for a 24" bike, this bike is ready from months but is still waiting for a reliable motor to be used at >280rpm, we will see if the XD 2speed could be the one. A 25-30kph limited system in a 13Kg bike (9s4p 18650 + 3Kg motor included) is a non sense for me, since I can reach and maintain that speed without assist no problem with this bike.....
I hope that this motor, with the 2 speed would be able to survive the tests, than, eventually, I may decide to weld the frames with slightly wider Dropouts, so that the 146mm could fit in any case.....

I'll let you know all the details and will post pictures when I'll really have my hands on them.....
 
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