Doc's Watercooled Hub motor project ( 5403)

[Doctorbass]

UPDATE ON PAGE 3 ( new principle and more efficient and simple) http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=39933&start=30

Yes... This motor still have not make a single rotation on any of my ebike, but it will be liquidcooled !

I want it to me a REAL beast and to have it able to sustain that title of real beast during an entire run !!!

No more motor overheat problem.. no temp gauge to watch and that require reducing the throttle!

I already remachined the axel to have 3 x 10 gauges wire to fit perfectly and the other side of the axel a similar groove but that will contain the 2 brass pipe for the inlet and outlet!

To do that i needed to replace the smaller 6004 bearing of the axel by another 6005 to accomodathe enough room to have the two pipe required room.

The big probelm was to have enough I.D. to have enough liquid flow to make efficient the cooling, but the room for the pipe is restricted. I finally found a great way to have really thin tube thickness and not too gfragile. I found that using TV telescopic antenna brass tube is just perfect !!

So the I.D. is like 1/4 inch !! and the O.D is like 9/32" !!

I dont have the time and $$$ to have custom machined aluminum path for the liquid so i dediced to go with copper tube

Problem with copper tube is that the effective surface that can be in contact with the aluminum of the stator is really low .. unless the tube are square.. but i have normal tube .. and they are round !

So the way i found is to add some 22mil copper sheet that increase the effective surface in thermal contact with the aluminum of the stator and to solder them to the spiral copper tubes.

No worrie i will post pictures of the project soon. I expect to have 4 foots lengh of the 1/4" I.D. copper tube touching the copper sheet that are in contact with like 70% of the aluminum of the stator.

Worst case of use of that liquid cooling setup might be to extract like 4-5kW of heat for a 16-17kW power input... at 130-140km/h

Doc

[Doctorbass]

Some first pics:


I wil add some aerospace grade NUSIL thermally conductive Adhesive between the aluminum and the copper as well.

Also it's not shown on the pictures yet but i will also cover the center 6 branches star aluminum with copper sheet that will have a spiral of copper tube soldered on it. ( see the image on the paper sheet ( wich represent the center copper sheet that will be placed on both side of the motor

I might call it PORJECT SPIDER ( the desing look like a cobweb )


Doc

[hjns]

Just an idea, if you fill the motor with a little bit of ATF oil, it will much better transfer the heat from the coils to your superduper copper pipe filled with supercool liquid. Alternatively, why don't you circulate oil in the whole motor, and use the copper pipe as radiator in front of your bike?

Anyway, I love what you do, so keep it up!

[Doctorbass]

Just an idea, if you fill the motor with a little bit of ATF oil, it will much better transfer the heat from the coils to your superduper copper pipe filled with supercool liquid. Alternatively, why don't you circulate oil in the whole motor, and use the copper pipe as radiator in front of your bike?

Anyway, I love what you do, so keep it up!

I see your suggesting, but I dont want any oil dripping probelm over the time....

Also.. my side cover are perforated with multiple holes already.. to contribute to cool it down

Doc

[Bison_69]

Hi Doc,

Let me know if you need any scale CAD drawings (2 or 3D) for your project....


Ok Bye...

[wojtek]

looking forward to the first video in action

subscribed*

[Doctorbass]

Hi Doc,

Let me know if you need any scale CAD drawings (2 or 3D) for your project....


Ok Bye...

Thanks ! i keep that in mind!

Doc

[nechaus]

Just a Suggestion.
What about using sometype of thermal paste (micronised silver) in their or heat transfer material.. not just bare copper ? stuff we use in pc's..

Be awesome to get them pipes icy cold

[auraslip]

Doc, did you see keyne's liquid cooled motor? https://sites.google.com/site/shelbyele ... -dirt-bike

[rojitor]

This is very interesting. Subscribed.

[rojitor]

Btw i have got a 5403 too, will you use single freewheel doc?

[Doctorbass]

Btw i have got a 5403 too, will you use single freewheel doc?

Yes, but i'll have enough space for a freewheel with the 11 tooth if i need

Doc

[Doctorbass]

Doc, did you see keyne's liquid cooled motor? https://sites.google.com/site/shelbyele ... -dirt-bike

Yes i saw it, The X5 stator have no corner where to put these 45 degree sheet of material like these cromotor or 9C or HX motors. That's why i wanna use copper tubing with copper sheet surface enhencement.

But yes keyne's cooling idea was nice too

Doc

[Doctorbass]

Some update on the heat collector parts for the tubing fabrications:

( i'll use a 20T press to flaten a little bit center the spiral to improove the thermal contact, but just enough to not reduce the I.D. too much.)

Doc

[Trackman417]

You just aren't happy with anything stock are you?
Subscribed!

[Doctorbass]

You just aren't happy with anything stock are you?
Subscribed!

Yes.. everything must be mod according to our own requirement


Today i just finished to assemble all that copper together and soldered everything with some 50/50 lead.

I know it appear a little bit heavy but this is the compromise i found for guarantying that there is no possible leak.. so i choosed to keep the concept of copper tube combined with fins that suck the heat from the stator structure and bring it to the copper tube with the lead junction.

I will also put a high performance thermally conductive adhesive silicon that will fill the area between the copper fins ( blades) and the stator structure. so there will be no insulating air gap .. just some thermal conductive stuff

As well, all the radial copper blades will be bended to be as close as possible to the stator 6 branches.

This is the first half( side) of the copper system. I will begin the second half this weekend

If you have any suggestion to improove that existing concept, please let me know!


Doc

[deVries]

[nechaus]

I think you have one of the most copper filled motors out there lol

[keyne]

I'm really interested to see how your project goes. It is very similar to my first attempt (undocumented) at cooling a hubmotor - I decided it was too hard, too much work and would add too much weight in the end. How are you planing to get the coolant in and out of the motor? Are you going to do two sides or just the one? Good luck - looks good so far

[keyne]

One thing you might want to add to your design is to put thermally conductive epoxy all over the windings to try to improve the thermal path from the windings to the stator. The air gaps in the windings and the winding paper is the major barrier. I found with mine that there was a large delta T (up to 40degC) which was improved substantially by adding about 60g of themal epoxy to the sides of the windings.

[Cowardlyduck]

Hey, I'm not sure if it's possible to do, but it would be cool to see how much power it takes or saves in doing this.

I.e. It would be cool to see, how much power it takes to maintain, say 80kmh, on the flat before you add the water cooling, and then, how much more (or less, due to better efficiency) after you add the water cooling since the power for pumps, fans etc will coming of your pack still.

Cheers

[Doctorbass]

I am using the two side of the axel one side have the phases, hall and temp sensor wires and the other side have the two 1/4 tubes (IN and OUT).

I modified the axel and the side cover to accept two 6005 bearing instead of one 6005 and one 6004. The side with the replaced 6004 for a 6005 have the two tubes. I will post pictures of that soon.

I am 100% sure that the power required by the pump ( 24W) will be largely compensated by the efficiency gain in power!!! at high temp the hub motor are like half their normal power...

This will improobe the max power duration for each ride ... or the average power level as well.

I ordered these:

Swiftech MCP655





Swiftech MCR-320 Quiet Power Series Radiator




Doc

[Doctorbass]

One thing you might want to add to your design is to put thermally conductive epoxy all over the windings to try to improve the thermal path from the windings to the stator. The air gaps in the windings and the winding paper is the major barrier. I found with mine that there was a large delta T (up to 40degC) which was improved substantially by adding about 60g of themal epoxy to the sides of the windings.

That is a nice idea.. maybe trying with my special aerospace thermally conductive adhesive RTV

Doc

[keyne]

I'm curious to know where you are going to mount the pump and radiator?

I found with my system the limiting factor was not the pump or the radiator but getting heat to transfer from the windings to the stator more efficiently. A larger pump or larger radiator doesn't help much there. You'll find it makes a huge difference compared to an air cooled motor - I don't have to worry about overheating my motor anymore. Also are you going to use a fan on your radiator (eg. for when you have stopped after a long climb)

[Bison_69]

Hi Doc,

Be carefull with this company... there are complain from customers on their website which says that they are not respecting their waranty...

http://www.swiftech.com/warranty.aspx

Swiftech disclosure.jpg

SwifTech Disclosure catch

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I think you would be better off buying a motorcycle or automotive electric water pump from a small car serie like the one found in a Toyota Yaris or any other make. (which you could buy locally as well)

Bye...