axial generator with lamination core

[SparWeb]

Now I feel torn!
Do I applaud the initiative to begin a radial iron-core generator from scratch?
Or do I persist in asking you to test that other generator, please, since the power tests would be so interesting?!

[mbouwer]

Testing of the axial can happen if I meet a windmillfriend in my region who has more knowledge of electricity.

Now it's much more fun for me to try, with input of the forum,
to build a radial version.

[mbouwer]

The mandrel ( externally ø 98 mm ) that I need as support to reduce the outer diameter of the stator package.

[mbouwer]

The lamination package has been mounted on the mandrel and it's outer diameter has now been reduced to ø 147 mm.

[mbouwer]

The package is 34 mm wide and the bridge is 10 mm.
Now I want to shape the housing.

[Adriaan Kragten]

I have counted the number of armature slots in your picture and I found 30 slots. This is a very unusual number as normally it is 24 or 36 for stampings of small asynchronous motors. So you should first decide what kind of winding you want to have in this stator and what pole number of the armature matches with the chosen stator stamping. For 30 stator slots, 15 coils can be laid as every coil uses two slots. If you use a 3-phase winding, you will get five coils for each phase. With five coils per phase, you have only two options to connect the coils. One is to connect all five coils in series and one is to connect all five coils in parallel. With this stator stamping, it isn't possible to make a high pole number generator as explained in my recent report KD 708 because for this generator type, the number of coils per phase must be even.

[mbouwer]

Thanks for the comment. I'm going to find a stamping with a higher number of slots.

[Adriaan Kragten]

You can use a stator stamping with 36 slots for a PM-generator with a high pole number. My public report KD 580 describes a small 34-pole generator using the stator stamping of a 6-pole motor of Kienle & Spiess frame size 80. My public report KD 614 describes a big 34-pole generator using the stator stamping of a 6-pole motor of Kienle & Spiess frame size 132. For the small generator, all parts except the stamping have to be made. For the big generator, the housing and the shaft of a standard asynchronous motor is used.

The winding pattern of the 3-phase winding is the same for both generators and is given in both reports. In figure 1 of KD 580 you can see that the three upper coils U1, U2 and U3 are about opposite to three north poles and that the three lower coils U4, U5 and U6 are about opposite to three south poles. So it is very important that the upper bundle of three coils is connected to the lower bundle of three coils such that the voltage generated in the upper bundle is strengthened by the voltage generated in the lower bundle. If all coils have the same winding direction, this is realized if coil end UB is connected to coil end UD. To clarify this, I have added figure 1 of KD 580 as an attachment.

[mbouwer]

A study of how to modify my lamination core so that it also looks more like the direct drive of a professional turbine ( With 20 revolutions per minute for example )
Here I have 60 slots.

[mbouwer]

At professional mills also the rings of the laminations are composed out of many pieces.

Can we shape a tailored package for a small radial direct drive generator?

[mbouwer]

2 rings to enclose the laminate package for machining and as a mold to drill.

Pitch circle ø 150 mm / drilling bit 3,5 mm

If I make 72 slots (3.5 mm width)  then the teeth will become 3 mm wide.

The thickness of the bridge is then 10 mm

[Adriaan Kragten]

A study of how to modify my lamination core so that it also looks more like the direct drive of a professional turbine ( With 20 revolutions per minute for example )
Here I have 60 slots.

A stator with 60 slots can be used in combination with an armature with 58 or 62 poles. In this case you have ten coils of phase U, ten coils of phase V and ten coils of phase W. The ten coils of one phase are divided in two bundles of five coils which are lying opposite each other. All coils of one bundle are connected in series. The two bundles have to be connected such that the generated voltages are strengthening each other.

For this generator type, only half the magnetic flow through one stator spoke is flowing through the bridge in between the bottom of the groove and the outside of the stamping. So this bridge can be much smaller than for a generator with a low pole number. But you need a certain minimum width to make the stamping strong and stiff enough. If I look at the picture I think that the cross section area of the groove for the winding is rather small.

[Adriaan Kragten]

2 rings to enclose the laminate package for machining and as a mold to drill.

Pitch circle ø 150 mm / drilling bit 3,5 mm

If I make 72 slots (3.5 mm width)  then the teeth will become 3 mm wide.

The thickness of the bridge is then 10 mm

If you make the sheets yourself, it is essential that there is an electrical isolator in between the sheets. This prevents the flow of electric eddy currents perpendicular to the sheets.  Prevention of eddy currents prevents a strong sticking torque which is increasing about linear to the rotational speed.

[mbouwer]

It's my search how I can make a suitable laminates core.
I now shape the slots by grinding. Then  I polish the laminates and want to glue them into a package.

Do you think the glue can form an adequate electrical isolator?

[Bruce S]

m-
Not knowing the type of glue you will be using, however I personally would not rely on glue as an insulator.
You would be better off using shellac, or the craft paper used to build transformers.
Other will have better input tho.

Cheers
Bruce S

[mbouwer]

This is the glue I use to build the package.

I also wonder now if I should use stainless steel to shape the housing around the lamination package.

[hiker]

Epoxy paint,,then glue ,,😜

[mbouwer]

The laminated stack with 60 slots for which I now want to shape a housing.

[mbouwer]

The housing.
I want to lock the stack between the stainless steel cooling ribs.

[mbouwer]

The lamination package clamped in the housing. I now want to make axle and hub.

[hiker]

Looks great ,,what type of machinery do you have,,Great work as Usual,,!  What’s your plans on keeping the wire from sliding out of your Stator,,few years back I made one from wood,,wire kept working it’s way out as I wound the stator,,it was just a experiment,,flop at That,,😜

[mbouwer]

The idea is to later push the 30 coils in the slots along with a little glue.
Now first I want to try to make a suitable axle.

[GreenTeam]

Thanks for the comment. I'm going to find a stamping with a higher number of slots.

yea right....the number of slots means nothing really.
Like seriously, You can have over a hundred slots lol.
Now, what kind of winding is being used on this stator? Wave? Progressive Wave? Retrograde Wave? Lap wound? Preformed coils?? Overlapped
I think 30 is actually a really nice number to start with actually.
Read some books, there are ALOT of books that break it down, and the only purpose the stator metal serves is for focusing flux.
You dont even need to plave the wires in the slots to do that either! Hence, Wave winding

[mbouwer]

The stator with 60 slots is now the starting point.
Around it I want to try to shape all the matching turbine parts.
For example like at this professional generator.

[mbouwer]

The shaft and hub with suspension flange, rotor suspension ring and blade flange.
Now I can proceed with the stator bracket.

[mbouwer]

The stator suspension bracket.

When I have mounted the axle and hub in the stator I can continue with the rotor and the magnets.
The maximum size of the outer diameter of the rotor may become 126 mm.
So on the circumference I have to shape 58 or 62 poles.

[bigrockcandymountain]

I would be very interested in seeing some pictures of these parts in progress being made.  Your metal fabrication skills are amazing, and i would like to know more details how you do it as well.

[mbouwer]

It are those windmillfriends on the forum, who succeed in generating ( part of ) their energy needs themselves,
who inspire the most.

[mbouwer]

Put together it looks like this.

[mbouwer]

It looks to me like more and more valuable information about shaping a generator is coming out on the forum. So I will first proceed with the parts for the blade suspension.

[mbouwer]

Base ring for the blade suspension.

[mbouwer]

Fixed cover plate and blade suspension mounted.

[kitestrings]

Oh, very nice mbouw.  I like some others would be interested in seeing how you are casting and fabricating your parts (or, maybe they are all 3-D printed... just kidding).  Looking forward to seeing more.  ~ks