Motor Question ?

[WXYZCIENCE]

Can this type of motor be converted to a 3 phase genny?

Are there arc magnets to fit it? Joe.

[wdyasq]

Looks like a 3PH 4 pole ~5kw/6.75hp motor.  I think it would make a good generator. Will take about 6M or so blade set and associated tower.

Of course our resident expurt is zubbly.  I feel sure he will chime in.

Ron

[zubbly]

hi WXYZCIENCE!

that is a perfect motor to convert. the arc segment magnets we see for sale form an outside diameter of 3.8 inches, so i am pretty sure they are out of the question for your 5.25 inch stator bore.

on conversions that size i have found the 3/4 round by 3/8 thick mags to be the most promising size for a conversion that size. you have the standard 8-10-12 coil spans and basically your magnet pole will be the width between the coil legs of the 1-8 span. you only need to locate the star point in the connection and add 3 leads to it to give you the full connectability of star and delta (1 and 2 circuit).

i did a 3hp conversion last year with a bore diam of 4.25 inches. you rotor would likely need one more magnet wide on the rotor. this one took 15 magnets per pole.

you can find some pics of the converted 3hp rotor on pages 16 and 17 at the photo gallery.

http://www.anotherpower.com/gallery/zubbly?page=16

hope this helps!  

zubbly

[hvirtane]

did a 3hp conversion last year with a bore diam of 4.25 inches. you rotor would likely need one more magnet wide on the rotor. this one took 15 magnets per pole.

Do you have any specifications available of that conversion?

How much did you pay for the magnets?

- Hannu

[WXYZCIENCE]

I reworked the photo to 56K, still looks good 50% jpg now. Joe

[zubbly]

hi hvirtane!

that was the genny i made last fall. the shaft got bent like a banana when i was attemting to raise the tower and dropped it. so never did get any performance figures. an currently working on re-erecting the tower and am making a new genny.  the shaft can be replaced, but i will do that some other time.

you can view the conversion process from page 15 and on in the gallery.

http://www.anotherpower.com/gallery/zubbly?page=15

i honestly don't remember what i paid for the magnets.  it took a total of 60 magnets for the rotor (3/4 round by 3/8 thick)

rotor diam-4.222 inch

rotor lamination length-4.322 inch

stator bore-4.254 inch

36 stator slot

aluminum cage-4 inch OD with 1/4 inch wall thickness

outside dimentions of magnetic pole made from 15 mags-2 .375 wide by 4.332 long

mags were spaced approx 22mm on centres for length and width

face of rotor turned to 3.390 inches

zubbly

[WXYZCIENCE]

Thanks Zubbly, Here is the star connection, looks like they are dual wound, am I correct?

I found a 5" nylon bushing, will it work in place of aluminum? Can I use rectangular 1x2x1/2 neos? The length of the rotor is 4"

I saw one of your conversions you had bands on the neos, if I band the magnets in with stainless will that work? This is the rotor.

Joe.

[zubbly]

often what you will see is motors done with 2 or more wires in hand. its just a combination of smaller wire which makes it easier to feed into the slot, but has the same effect as 1 large wire.

personaly, i wouldn't use the nylon as i don't think you will get any type of glue whcih can bond the mags to the nylon.  i use aluminum tube, or you could use brass or non magnetic stailess. i use loctite bearing mount to hold the mags in. it really gives a powerful hold. the steel bands you saw in one photo are just pipe clamps to keep the mags down tight while the loctite hardens. they are removed after.

either the laminations or the magnets have to be skewed by 10 degrees for a 36 slot stator such as yours.  you can not skew those 2x1x1/2 mags on the rotor. you could try the method jam used with the one pole offset. not sure how well it will work out though for the cogging, and it will cause imbalance issues. i usually prefer to use the small round mags as they are easy to work with and are very easy to form the size of magnetic pole you wish to make. you can also use a thin wall fibreglass tube or possibly a thin wall nylon tube and fill the empty space with epoxy after. do not use fibre glass resin as it does not bond to the magnets well. you should also check on the temp rating of the nylon if that is what you are going to use.

if you wish to cut the rotor down slightly further, you could wrapp carbon fibre thread over the magnets after and impregnate with resin. ronb mentioned this before and think it may work out well. of coarse you end up with a slightly bigger mag stator airgap.

hope this helps.

zubbly