Alternative to resin based axial rotors

[Windytech60]

More than a couple of years ago I attended a seminar in Missouri provided by the OtherPower Team and the Evergreen Institute. It launched me on what seems as a never ending quest to improve the original build. It occurred to me recently that I should share some of these improvements with others in the hopes I may get some feedback on their opinion of my designs.

I have been very lucky to have the opportunity to access a lot of help in areas that I lacked knowledge. Please feel free to express your opinions as they are the very reason I post my thoughts and designs. I will say that I have been somewhat successful in producing a commercial version and there are a few models sprinkled around the world.

My first production process change I developed was to replace the resin and stainless steel band with a pre-engineered single piece composite plate that is attached to the steel rotor plate. I call this component a rotor plate insert. It makes assembly a breeze and more safe for magnet loading.

Rotor Plate Insert



Rotor Plate Insert attached to Rotor Plate



Rotor Plate with magnets loaded

[Mary B]

What material are you using? I have a laser cutter and this type of stuff is right up its alley. I could do up to a 12 inch rotor

[Smithson]

Nice idea.  How do you align the insert to the other insert on the opposite rotor?  Do you still need an aluminum (or whatever) template with the four bolt pattern?  Does the insert mount permanently. Would cutting a 3/8 plywood insert with a jigsaw work as well?  Or would plywood interfere with the moisture sealing process at the base of each magnet?   Again nice idea,  Arch

[Windytech60]

Mary,

I did not manage to get the image of the rotor plate insert minus the rotor plate loaded properly. I will attach it now.

[ Attachment Invalid Or Does Not Exist ]

After months of research specifically to determine the best method of commercially fabricating the rotors my composite research team came up with this. Truthfully, I do not immediately know the composite chemistry (I will get the detailed mix) but I had them create a professional mold master. I specified the finished product to have a minimum working temperature range of -40 to + 160 degree F, a very low temperature expansion ratio and be compatible with a high strength adhesive required to attach the rotor insert to the double powder coated rotor plate along with a long list of other requirements. The blank is poured with a gel coat surface then the magnet insets are CNC cut. I performed a long series of dynamic tests on the design to determine a low cost method of passive cooling using a V shaped grove between magnets to create a turbulent air boundary at the stator surface.

As you may determine I have spent a bundle (in excess of $100,000 of my own not to mention other sources) researching this Axial Flux Permanent Magnet Alternator. I must admit, at first, I had a personal commercial interest in this product. In the past seven years I have studied it to a fine degree. I did manage to develop each of the required commercial mass production manufacturing processes and produced a couple dozen units for field tests that are placed in and outside the US. After much contemplation and market research have determined it is much more "FUN" to move the technology forward by making my research available to others with the same interest. Yes, I'm very close to retirement.

If you have the laser cut capacity to perform the surgery for the magnet insets I might have the Team pour you a couple of blanks to try. I am working on another method of manufacturing the blanks that will eliminate the composite pour and machining the magnet insets completely. I recently closed my Research Laboratory in central Missouri to move north of Tulsa Oklahoma (more wind). I have a website (Sorry, NO LINKS in accordance with normal policy unless I hear otherwise: DamonHD) albeit not very well developed. Web design is most definitely not my strong area of expertise.

As you might imagine my rotor fabrication ideas are just the tip of the iceberg so-to-speak. As I find time, I will attempt to provide the visitors to FieldLines as much detail as possible on my data.

Please feel free to ask.

I did move all my fabrication equipment to Oklahoma and can still produce components for the Air-Boss 1400, Air-Boss 2800 and the AB-10 most of which you will recognize for OtherPower training. I thank the OtherPower Team for providing me the training that put me on this research path. It is a fantastic journey.
 
   

[Windytech60]

Smithson,

To answer your questions

The rotor magnet insert and powder coated rotor plate are attached to each other using a specially selected adhesive then placed on an alignment jig to keep the rotor components centered and aligned. As with the composite material the rotor insert plate is made of, I do not know the adhesive material that is used. I will get that detail for you as well. I will say it is expensive and since developing this particular manufacturing process I have researched alternatives and came up with another solution. By modifying the rotor plate and placing treaded holes in strategic points along with holes placed at the same point on the rotor insert plate one could use plastic or stainless steel screws to attach the components.

I have not completed any research on the idea using plastic screws looking at shear strength, expansion ratios or weathering. I would fabricate the first with stainless steel. By the way, it is only somewhat related but I would not use aluminum for a couple of reasons. Dissimilar corrosion for one and secondly aluminum is not magnetic but IS Para-magnetic. Rake a moment to research the term if you haven't before. It's a good read.

When the adhesive is set I place the magnets, then seal them in the inset with a small amount of silicone around the outside edge. One detail you cannot see in the picture is that each "magnet slot" is slightly larger on top to allow for easy (safe) magnet insertion, proper magnet alignment and a good clean silicone weather seal. One cannot allow water to accumulate and possibly freeze in the slots. Do not allow any adhesive or place any silicone between the magnet and steel plate. This may cause the magnets to have different heights and ruin the rotor fabrication. Also one has to be careful to insert the magnet in the correct orientation. I meant to change the insertion process slightly to place the magnets on the plate (using the aluminum guide), verify the proper orientation then attach the rotor insert plate. This would remove the possibility of inadvertently installing the magnet incorrectly and having no method of recovery.

If you wish to pursue this rotor insert system and fine tune the process I will be glad to assist.

I also realized the image of the rotor insert plate still did not take. I will attach it again.



   

[hiker]

could use pins ..or screw the it down to the rotor...otherwise its just the glue holding it togeather...

[Mary B]

Chlorine based composites cannot be laser cut, Delrin can and I think it fits your needs except it tends to be slippery. Otherwise laser cutting cab be fairly precise but not as good as a cnc, fit will be close but material can behave odd as it is cut plus laser cutting will leave a sloped cut.  It would not need to be same thickness as the magnets to be effective since all the force from magnet wanting to move will be out to the edge.