Thread Tools
Old Aug 28, 2015, 08:04 AM
aliazhar is offline
Find More Posts by aliazhar
Registered User
Plano, TX
Joined Jun 2007
27 Posts
Discussion
Axial Flux alternator

i designed it: http://www.helibug.com/HBPBAXL.htm
aliazhar is offline Find More Posts by aliazhar
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 15, 2015, 03:57 AM
fifa16shop
A moderator felt this post violated the following rule: Redacted Content.
Old Sep 16, 2015, 08:46 PM
aliazhar is offline
Find More Posts by aliazhar
Registered User
Plano, TX
Joined Jun 2007
27 Posts
rules???....
this is not even related to any of the junk we discus on forums !
oh well....whatever !
ha
aliazhar is offline Find More Posts by aliazhar
Reply With Quote
Old Sep 30, 2015, 12:36 PM
Hummina is offline
Find More Posts by Hummina
Registered User
Joined Jul 2014
667 Posts
what are the chances of making a smaller version of one of these generator/motors that people could use for models or something? Isn't there anything being produced already. I thought axial flux motors were the best power to weight machines available. maybe this could do better with permanent magnets?
Hummina is offline Find More Posts by Hummina
Reply With Quote
Old Sep 30, 2015, 11:17 PM
Christian Lucas is online now
Find More Posts by Christian Lucas
Registered User
Germany, BY, Gräfelfing
Joined Jan 2003
566 Posts
Hi,
Hummina ,he is using permanent magnets with airgap coils . For a moore powerdens version read this paper or type in google Yasa motors pdf ,you will find a lot of how wow .
http://www.mojaladja.com/upload/elmo...%20machine.pdf
Christian Lucas is online now Find More Posts by Christian Lucas
Reply With Quote
Old Oct 01, 2015, 01:55 PM
pem is offline
pem
Find More Posts by pem
pem
Registered User
Frankfurt Intl, Germany
Joined Feb 2004
301 Posts
Quote:
Originally Posted by Hummina View Post
what are the chances of making a smaller version of one of these generator/motors that people could use for models or something?
Hi Hummina - look at this jewel Gary Jones design from 2004
Those were the times ...

Peter Maul

But true - its not a two sided approach, but that had been done as well
pem is offline Find More Posts by pem
Reply With Quote
Old Oct 01, 2015, 02:20 PM
Hummina is offline
Find More Posts by Hummina
Registered User
Joined Jul 2014
667 Posts
doesnt seem he sells the design on the site you gave

that was a long time ago he made it. I dont know numbers to compare its performance but how does the motor do? theoretically it should be great.

thanks Christian this is a great read for me and I have just a couple questions:

how does an epoxy coating on the magnets reduce eddy currents?

and this confuses me :
"The iron in the stator of the YASA motor is dramatically reduced
when compared to other axial flux motors, typically by 50%,
causing an overall increase in torque density of around 20%."
how can they decrease the iron in the stator yet get more torque? is it due to the stator shape and it is utilizing all the iron? I think I remember seeing a visual representation of flux saturation and it really only happens at the ends of the stator teeth and the rest of the stator is not saturated, so in a way the iron is not fully used in the outrunner hammerhead tooth shape and this is utilizing all the iron?
Hummina is offline Find More Posts by Hummina
Reply With Quote
Old Oct 02, 2015, 02:33 PM
Christian Lucas is online now
Find More Posts by Christian Lucas
Registered User
Germany, BY, Gräfelfing
Joined Jan 2003
566 Posts
Hi Hummina,

Simple answers : eddy current will be reduced by using epoxy glue to glue the magnets on the backiron . As the epoxyglue isolate the magnets from the backiron electrical the part that are effected by the magnetic fild are smaller so the eddycurrent circuite is smaller so the induced volts are smaller . It is the same wy we want thin plates for the statoriron .As thinnernas better if the isolation becomes not to thick in relation to the ironplates.

The reduction of iron is related to older ,showen in the article normal build axialflux motordesign . With the 12 slot 10 magnet system every motordesign has less iron as all fluxpas are shorter and the as you have only to carry the smaller flux of the magnets parts and only over 30 degree you need much less iron to do it. A normal 2 pole motor has to carry the full amount of magnetic flux over 180 degree you need a big iron highway to allow all fluxlines to go with low resistance . This iron highway makes a motor heavy .
Christian Lucas is online now Find More Posts by Christian Lucas
Reply With Quote
Old Oct 03, 2015, 01:23 PM
Hummina is offline
Find More Posts by Hummina
Registered User
Joined Jul 2014
667 Posts
without epoxy behind the magnets they would fall out an d then the motor would fall apart and that Seems more so the benefit of the epoxy, unless the magnets were small and each pole were built of
Many and would be less conductive as you say. And then if they were to use many smaller magnets for each pole why not built it into a hallbach array as the flux wouldn't even be making it to the backiron to cause eddy losses there. ..seems an even better solution. Why don't they do that? And lighter besides.

With a typical outrunner when saturation occurs is it really just the teeth ends that are saturating? How far down the tooth is there useful flux?
Is flux on the outside of an outrunner lost regardless..if I were to add an induction coil there and connect it to a rectifier and led lights would I be taking advantage of lost energy or will it suck from the motor's useful flux a little?
Hummina is offline Find More Posts by Hummina
Last edited by Hummina; Oct 03, 2015 at 01:31 PM.
Reply With Quote
Old Oct 03, 2015, 02:59 PM
Christian Lucas is online now
Find More Posts by Christian Lucas
Registered User
Germany, BY, Gräfelfing
Joined Jan 2003
566 Posts
Hi Hummina ,

the Siemens airplane motor and our most powerdens motor use a Halbach array but you have to slice the magnets the same direction like the lamination of the statorplates are layed together . We use 1 millimeter thick magnetparts . If you have a motor with low magnetic flux it can be used the best material to lower eddy current ceramic magnets made from ferrite iron that is not conductiv and ha so near no eddy current los .
See allthough this small,axial flux motor with Halbach magnet systeam , http://www.launchpnt.com/engineering...-motor-design/ .
Christian Lucas is online now Find More Posts by Christian Lucas
Reply With Quote
Old Oct 04, 2015, 10:07 PM
Hummina is offline
Find More Posts by Hummina
Registered User
Joined Jul 2014
667 Posts
That link, thanks I looked at everything they have.
What about the flux in a standard outrunner, I thought saw a picture showing that when saturation occurs it'd really just at the tooth. Maybe much of the stator is wasted?
And what about the flux on the outside of an outrunner, if I added coils to harness it would it take from the motor's power?
But more so please tell me at what point eddy currents become an eddy current brake? Is it largely determined by proximity of conductive metal to magnets or electromagnets? The motor
I designed and want to get made has an aluminum wall beside the stator. The manufacturer said its no
Problem but...
Hummina is offline Find More Posts by Hummina
Reply With Quote
Old Oct 05, 2015, 12:48 AM
pem is offline
pem
Find More Posts by pem
pem
Registered User
Frankfurt Intl, Germany
Joined Feb 2004
301 Posts
Hi Hummina, think again about your motor concept ...

.. much of the stator is not wasted but USED, saturation makes the head of the tooth loosing its value for the flux path IT becomes WASTED weight

... outside of the outrunner is hopefully no flux at all (because then wasted for the torque production inside), but if you USE the rest and harvest it outside it TAKES flux in movement, makes voltage and if you use this as current it will produce a flux witch acts as a brake for the motor movement.

... every eddy current TAKES flux, makes current (that heats the iron or aluminium or copper or whatever conductive thing it is in) and the current acts against the flux or the movement it is result of. Thus: every eddy is a brake...

No conductors into a changing magnetic field. Even the copper is a brake itself. Even the permanent magnet is a conductor within the changing magnet field of the stator. Every part of the motor might be a parasitic eel ...

Peter Maul

PS: and take a look at this: http://www.rcgroups.com/forums/showthread.php?t=997243
pem is offline Find More Posts by pem
Last edited by pem; Oct 05, 2015 at 01:04 AM.
Reply With Quote
Old Oct 07, 2015, 11:51 PM
Hummina is offline
Find More Posts by Hummina
Registered User
Joined Jul 2014
667 Posts
E
Quote:
Originally Posted by pem View Post
Hi Hummina, think again about your motor concept ...

.. much of the stator is not wasted but USED, saturation makes the head of the tooth loosing its value for the flux path IT becomes WASTED weight
when saturated it becomes wasted ok but how much value does the deep inside of the tooth beside the bearing tube have at this time the tooth is saturated and is this deep inside even beneficial iron? Maybe it's there more so for fabrication ease ..or to have the aluminum bearing tube further away, or maybe it's useful?.

.. if you use this as current it will produce a flux witch acts as a brake for the motor movement ok. Thank you. Please tell me how you would "use this as current". I imagined the strongest eddy current would be produced by having the closest conductors nearby the magnetic field. Proximity and conductivity. But are you saying you can increase the eddy currents by something else? Yes , how use as current?

... every eddy current TAKES flux, makes current (that heats the iron or aluminium or copper or whatever conductive thing it is in) and the current acts against the flux or the movement it is result of. Thus: every eddy is a brake... [COLOR="rgb(244, 164, 96)"][COLOR="rgb(244, 164, 96)"]ok but how do they stop roller coasters and not have only negligible resistance and heat?[/COLOR][/COLOR] I'm guessing they use strong electromagnets for a short period? I thought maybe you could make a strong eddy brake just from permenant magnets but I guess the strength of the brake is equal to the level of flux and maybe an electromagnet is needed

No conductors into a changing magnetic field. Even the copper is a brake itself. Even the permanent magnet is a conductor within the changing magnet field of the stator. Every part of the motor might be a parasitic eel ...

Peter Maul

PS: and take a look at this: http://www.rcgroups.com/forums/showthread.php?t=997243
[COLOR="rgb(244, 164, 96)"]ill read the thread next. And do a search on YouTube!! There's probably a video. There's probably a video about everything. [/COLOR]

Ah I'm remembering I did look at TH first couple pages of kreatures projects! Great stuff. I'll look through it further but wonder why assumed 100% percent magnet fill would be good, and if it adds to inefficiency, and makes more audible noise? I read 100%fill makes more "noise" and wasted and to do it right you want to match the magnet shape to the stator tooth shape and using an..electric stethoscope..(ugh) ..get as close to a wave as your esc would produce. ?
Hummina is offline Find More Posts by Hummina
Last edited by Hummina; Oct 08, 2015 at 12:20 AM.
Reply With Quote
Old Jan 17, 2016, 08:57 PM
aliazhar is offline
Find More Posts by aliazhar
Registered User
Plano, TX
Joined Jun 2007
27 Posts
Quote:
Originally Posted by Hummina View Post
what are the chances of making a smaller version of one of these generator/motors that people could use for models or something? Isn't there anything being produced already. I thought axial flux motors were the best power to weight machines available. maybe this could do better with permanent magnets?
yeah i have one fully stand alone with a small gas/petrol engine - not published yet...but, here is something similar i have designed for the RC engine:
http://helibug.com/HBPFRC.htm


its designed for mid to high range rpm...
I had to protect my design this time as i have seen few copied some of my work in the past
aliazhar is offline Find More Posts by aliazhar
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Scratchbuilding an axial flux motor IBCrazy Electric Motor Design and Construction 5 Jan 06, 2011 08:41 AM
Discussion 5 lb Mini E-tek Axial Flux BLDC motor LipoEbiker Electric Motor Design and Construction 3 Dec 03, 2010 10:05 PM
Question Designs on Axial Flux motors, curious about coil types. Mr.EV Electric Motor Design and Construction 34 Nov 13, 2010 04:35 AM
Discussion Axial flux bldc motor KreAture Electric Motor Design and Construction 95 Oct 05, 2010 08:58 AM
axial flux motor design Ron van Sommeren Power Systems 0 Aug 05, 2004 10:16 AM