Faulhaber coreless motor patent, an interesting read

[mmagliaro]

I just happened to stumble upon this, and thought I'd share.
http://www.google.com/patents/US3360668

I believe this is Dr. Fritz Faulhaber Sr's original 1965 patent for the winding of the ironless rotor "The Faulhaber Coil",
as the company calls it.  This is the heart of the coreless motor.

The Micro-Mo (Faulhaber) site says that Dr. Fritz Faulhaber Sr. invented this in 1958, but
did not file the patent until 1965.  It doesn't say why.  The patent page has some cool drawings
of the motor windings and discussion of the assembly.

Thank you, Dr. Faulhaber.   

[victor miranda]

wow.
how did you find that?

it seems the patent is for a winding method?

I like the drawing of the commutator.

victor

[peteski]

Nice find Max!

And 50 years later, they still make them the same way. 

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[mmagliaro]

Let me see... how DID I find that?
I was looking at the Kato coreless motor.  Then I went to look at the 6mm and 8mm offerings from Faulhaber
at the Micromo website.  And I noticed something on the front page about "Dr. Faulhaber".

So I started web searching his name and found a great interview with the younger Fritz Faulhaber (the son)
who currently lives in Florida and runs the company.  In the interview, he mentioned his father and
the patent.  So then I headed over to the US patent office website and did a search on
an inventor name of "Faulhaber" and a title containing the words, "ironless rotor".

Luckily, that name and those terms are quite unusual, so his patent came right up.

Then I went back to the Faulhaber website to read the "about" section and it said Dr. Fritz Faulhaber invented
the thing in 1958, but it was patented in 1965.  Since the patent I found was dated 1965, I'm pretty darn sure
I have the right one.

[loyalton]

Peteski's photo brings to mind previous motor discussions.

I note the 7 segments on the commutator. Victor might like that(!) Is that maybe needed to overcome higher torque? Couldn't hurt . . .

And speaking of torque, would the 6(?) simultaneous turns of wire correspond to what Victor was doing in his recent "standard" motor experiments? https://www.therailwire.net/forum/index.php?topic=35052.msg411313#msg411313

As for patents, that's a US patent, applicable only for rights in the US. IIRC nowadays there are more rights/patents carrying over from jurisdiction to jurisdiction, but not back then. Espacenet.com lists European patents. Looking up Fritz Faulhaber, what I'm guessing is the one corresponding to the one in the US Patent Office is "Wicklung fuer electrische Machinen . . .", dated 1964 (no abstract, I think you have to buy it from the European patent office to really check). There is one dated 1958 for "Commutator for Miniature Motors" (no abstract, either). Then, as a guess, the 1958 patent is not necessarily the concept for a complete coreless motor but the beginnings of it.

[peteski]

Peteski's photo brings to mind previous motor discussions.

I note the 7 segments on the commutator. Victor might like that(!) Is that maybe needed to overcome higher torque? Couldn't hurt . . .

This is a photo of one of the coreless motors I dismembered few years ago.  That photo came from an old thread on the A-board: http://forum.atlasrr.com/forum/topic.asp?TOPIC_ID=63598  And yes, Victor liked the 7-segment commutator. 

[victor miranda]

I keep thinking it is 8 segments.

the patent states you can have 2 pole on up.

I have no clue how a 2 pole motor or any even number could start, however.

live and learn...

[peteski]

I keep thinking it is 8 segments.

the patent states you can have 2 pole on up.

I have no clue how a 2 pole motor or any even number could start, however.

live and learn...

I recall seeing a simple children's permanent DC motor with a commutator and 2-poles used to demonstrate working principals of this type of a motor.  This might have been in a Museum of Science or one of the Electrical experimentation toy projects.  It is far from perfect - it might sometimes need to be kick-started, but it demonstrates the principle.

This page shows a sample 2-pole motor: http://en.wikipedia.org/wiki/Brushed_DC_electric_motor

[victor miranda]

ah peteski...
yes I have built a demonstrator motor with two poles
and it does not self start.

I was pointing out that the arm/motor in the picture
looks like it has 8 poles.  also needs a kick start?

victor

[peteski]

ah peteski...
yes I have built a demonstrator motor with two poles
and it does not self start.

I was pointing out that the arm/motor in the picture
looks like it has 8 poles.  also needs a kick start?

victor

No, it is 7 segments.  Few posts earlier I posted a link to the original coreless motor thread on the A-board - there are more photos there, such as:


The metal strips radiating out from the commutator to connect to the windings correspond to the number of segments. There are 7.

[Ken Rice]

A bit off topic, but with the discussion of pole count I remembered this zero pole electric motor.  Requires a push to start.  Not very practical, but fascinating that it works at all:

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[CoalPorter]

A bit off topic, but with the discussion of pole count I remembered this zero pole electric motor.  Requires a push to start.  Not very practical, but fascinating that it works at all:

Is that what they used in some professional record turntables ? I recall turn tables that you could start and stop with your hand.

[Ken Rice]

Is that what they used in some professional record turntables ? I recall turn tables that you could start and stop with your hand.

In order for this kind of motor to work you need enough current to heat a ball bearing enough to deform it to very slightly elliptical.  Not exactly power efficient - I can't believe they'd use it in a turntable.  Also I can't imagine it's possible to regulate the speed anywhere near accurately enough.