Plastic Bonded Iron Powder Motors Can Halve the Cost and Double the Output of Electric Motors
11 October 2007
Researchers at Lund University (Sweden) have developed a technique for making magnetic components in electric motors from plastic bonded iron powder (PBIP) that can cut aggregate production cost in half and nearly double the output of the motor. The method is the result of 15 years of collaboration between researchers from the fields of electrical power systems and industrial production.
A key component in motors is the magnetically conductive material, usually made up of bundled laminated thin plates with coils wound around them. This type of motor construction contains many small parts and takes a long time to manufacture.
Together with his research colleagues Tord Cedell and Mats Andersson, Lund Professor Mats Alaküla has found that an alloy of iron powder in plastic (PBIP) functions well in such motor applications. The concept of PBIP is to surround the metal particles with insulating plastic material to provide low conductivity and high permeability. Properties of PBIP vary depending upon the shape of the metal particles and the choice of plastic material.
Centrifugal molding is used to arrange and pack the metal particles in an optimized structure—i.e., with better arrangement than if molded without centrifugation, but not too dense to allow contact between particles.
Molding melted plastic and iron particles also enables full freedom of form. Besides higher quality and greater freedom of form, the technique reduces the number of production steps from about 60 to only a few. The development of the material itself started in the late 1980s at the Section for Industrial Production, within the framework of the materials technology consortia, funded partly by what is now Vinnova (Research and Innovation for Sustainable Growth).
This research is funded with a total of SEK 12 million (US$1.9 million) over five years from Vinnova, the Foundation for Strategic Research (SSF), and Industri Kapital. A patent is pending, to be issued in late October. Whether a new company will be formed or the technology licensed out has not yet been decided by the researchers at CEMEC (Center for Electro-Magnetic Energy Conversion).
The technique is not suitable for high-performance motors, such as servo motors. But for fans, pumps, household appliances, and cars it’s a perfect fit. The technology can pave the way for new possibilities, such as facilitating the conversion of cars to electric hybrid power. It’s worth mentioning in this connection that all methods that lead to simpler and cheaper production indirectly help curb carbon dioxide emissions.—Mats Alaküla
A prototype of the technology will be on display at the Lund University Faculty of Engineering booth at the Technology Fair in Älvsjö, Stockholm, Sweden, 16-19 October.
In the automotive sector, I can see this working for small motors, such as those used to power windows and seats. It may also be useful in high-speed motors, e.g. for a water pump or electric supercharger. Adding a set of reduction gears increases cost again, so you might as well go with a conventional construction.
High-torque applications like starter motors need a lot of mechanical strength in the rotor, that a thermoplastic matrix may not be able to provide.
Posted by: Rafael Seidl | 11 October 2007 at 07:00 AM
I can see this technology being used to make light weight electric motors for R/C planes and possibly bicycles.
Posted by: gary | 11 October 2007 at 08:15 AM
Does 'double the output' mean that an electric motor using this technology in a car would use less electricity or does it mean that the motor would use the same electricity, but be smaller in size?
Posted by: | 11 October 2007 at 08:51 AM
I think they will find out ways to use reinforced plastics that is strong enough for high-torque applications. Don´t be sceptical because it´s not invented in USA.
Posted by: Mikael Johansson | 11 October 2007 at 08:54 AM
Anonimous "double output".
Iron powder in a plastic matrix implies very high resistivity and low loses in the core due to Foucault currents, so you can use higher induction in the same size or reduce size with the same power, however these gains could been restricted by the size of the coils.
The amount of energy involved in motors operation depends mainly of the load.
I think tht the great improvement is in cost reduction.
Posted by: Mario | 11 October 2007 at 09:59 AM
Not suitable for high performance motors but a perfect fit for electric hybrid cars. Is there a contradiction here?
Efficiency would normally have to be over 95% to compete with exiting high performance electric motors for PHEVs and BEVs.
However, if weight and cost are 50% less, a lower efficiency may still be aceptable for lower cost vehicles.
Posted by: Harvey D | 11 October 2007 at 10:47 AM
Another example of what I have been saying, as an Engineer, for a long time. There is no intrinsic engineering reason why an electrified drive train should be inherently more costly than a conventional drive train.
While low volumes and patents royalties will add temporary costs, over time, the electrified drive train is just inherently cheaper as well as significantly more efficient.
Unlike many who think the world is going to hell in a hand basket, this is yet another example that the premise is simply totally false.
Technological progress, so derided by the "intelligentsia" that is too stupid to contribute to it, is made every day and most of it is incremental.
This is a cost reduction potentially making construction cheaper to manufacture, for many electric motor applications.
Posted by: Stan Peterson | 11 October 2007 at 11:16 AM
Stan, your lack of intellectual self-esteem is stunning. Truly. Can you make it through just one comment without trying to brag about yourself and diss the rest of humanity?
Posted by: jack | 11 October 2007 at 11:25 AM
Harvey: By high-performance he means accurate rotational positioning and other such properties, not sheer power or efficiency. A fan, pump or electric car-drive motor needs grunt-power, a servo like an actuator needs to have sufficient power, but mostly needs to have a known response to the electrical inputs.
Posted by: Floatplane | 11 October 2007 at 12:06 PM
Stan, as an engineer you should learn to write coherent prose. There is no continuity in your two thoughts. I don't think anyone disagrees with your first assertion, the second on the other hand is quite specious.
If you had said "as a quantum physicist", I would have been more impressed. As someone who looks up formulas in a handbook and has no rigorous proof or understanding of what he's doing, then no, I'm not so impressed.
Posted by: bluegreen | 11 October 2007 at 01:19 PM
Halving the cost would be great , doubling the output would be very hard since 92 % efficiency is already achieved unless they mean doubling the output in the same size motor , and that would also be fantastic can you imagine saving weigth , space and becasue of this energy.
Posted by: gideon goudsmit | 11 October 2007 at 01:46 PM
Halving the cost would be great , doubling the output would be very hard since 92 % efficiency is already achieved unless they mean doubling the output in the same size motor or making the motor half the size with the same output, and that would also be fantastic can you imagine saving weigth , space and because of this energy. Amazing if it is true
Posted by: gideon goudsmit | 11 October 2007 at 01:47 PM
The SMCs (Soft Magnetic Composites) mentioned as a resources, would they work Linear Variable Differential Transformers?
Posted by: jcwinnie | 11 October 2007 at 02:58 PM
"If you had said "as a quantum physicist", I would have been more impressed. As someone who looks up formulas in a handbook and has no rigorous proof or understanding of what he's doing, then no, I'm not so impressed."
first of all, it's just insulting to suggest engineers have no understanding of the underlying physics behind the principles they apply every day. Second of all, the research physicists you admire so much spend 99% of their time on obscure physical phenomena which are of no use or application to any kind of human problem. It's an indulgence of social inadequates so they don't have to interact with real people in any meaningful way. You think that's an unfair characterisation? well it's your own medicine you're tasting.
Posted by: gavin walsh | 11 October 2007 at 04:23 PM
A "Quantum Physicist" sits around all day thinking...the Engineer takes those thoughts and puts them into action.
No rigorous proof or understanding? Just stop with the vitriol now, it is getting you nowhere.
Posted by: Patrick | 11 October 2007 at 04:36 PM
So you're a "man of action"?
Posted by: jack | 11 October 2007 at 05:39 PM
The research paper is quite good. I think this will improve existing "in wheel" motors dramatically, and the reduction in weight is needed as it is unsprung.
Posted by: John Schreiber | 11 October 2007 at 06:23 PM
I have worked quite a bit with magnetic materials in a plastic matrix where they perform quite well. Unfortunately when you put them into a centrifugal situation with heating you quickly run into a problem with creep inasmuch as the material strength may only be slightly reduced at temp but, coupled with the constant stress of rotation and the time element, the parts slowly get bigger until they rub and fail.thats the nature of the beast.
Posted by: fred | 11 October 2007 at 06:58 PM
I can see possibly halving the cost, since permanent magnet motor is expensive due to the rare transitional metals used.
But, I don't see how it can double the output, being encapsulated in a thermoplastic material that is not that strong to put up with the extremely high centrifugal force at a typical operating rpm for an electric motor, nor can we expect the "thermoplastic" to retain its strenght when subjected to motor's heat as a metal magnet?
Posted by: Roger Pham | 11 October 2007 at 07:27 PM
This is a great report. I can think of all kinds of applications, like portable power tools, for instance.
Oh, and about this:
Technological progress, so derided by the "intelligentsia"
Really Stan, can you name one member of the "intelligentsia" who derides technological progress?
Posted by: George | 11 October 2007 at 08:15 PM
"NO2 levels in the atmosphere are stabilized, and not rising." - Stan Peterson
"Who knew that nitrogen dioxide was a (major) greenhouse gas?" - Jack
[note how I specifically called NO2 it's correct name - now watch Stanley's reply]
"The IPCC knows that NO2 is a GHG. They discuss is at length in all their interim IPCC Reports. Try reading the TAR III or the current AR4. But then you wouldn't know that. The Elmer Gantry flunkout, showed you a movie and you converted." - Stan Peterson
That's quite a "typographical error" there, Stanley. You said NO2, I laughed at the fact that you said nitrogen dioxide is a GHG, then you doubled down and said that the UN knows that NO2 is a GHG and babbled on with a half dozen more acronyms and your standard pablum about Elmer Gantry.
Face it, Stanley - you're full of crap and everyone here knows it. Please stop making a fool of yourself by posting here. It's downright sad.
Posted by: jack | 11 October 2007 at 11:17 PM
I am like a pachyderm. I never forget. I can keep bringing the N02 thing up ad infinitum, until you are silenced. You are dismissed Stanley.
Posted by: jack | 12 October 2007 at 10:44 AM
Enough with the pachyderms Jack. I am almost expecting your next post to say something about those who meddle with elephants deserving a punch up the trunk.
Posted by: T2 | 12 October 2007 at 12:03 PM
My name is Richasrd Saare, I have spent the last twenty years designing a new style of electric motor and I feel that after 20 years as a main propulsion engineer and mechanic for Mercury Outboards. OMC, Detroit Diesel, Cummmins Diesel, ALCO Diesel, Perkins, Chrystler, Pontiac, and Harley Davidson, I honestly think this is a valid idea. I am a disabled veteran and do not have the funds to build this motor but have drawings and detailed explanations.
I did have a pre-grad PHD Mathmatics student at ASU look at the mathmatical feasability of the design. He feels that it could actually be a very strong motor. A Metalergist from Northern Arizona Univ. Agrees with the metals and materials I have selected.
I am a novelist because I had to get out of the Mechanics industry because of lung disease. I have successfullyt graduated from two twech schools and have nearly twenty years on line experience. Please contact me at 541-205-4924 or firstname.lastname@example.org
Posted by: Richard Abel | 12 October 2007 at 05:51 PM
Richard: by now you've probably missed the majority of the readers of this thread. You'll want to wait until another thread comes up.
jack: the NO2 thing's getting old.
Posted by: Neil | 12 October 2007 at 07:45 PM