Tim's Magnet-Piston Engine Design

[tim123]

Hopefully attached is an image of a sketch of the magnet piston arrangement I was referring to as 'Case 3' in this thread:
http://www.overunity.com/8429/mostly-permanent-magnet-motor-with-minimal-input-power/105/

So it's a view thru the coil & core - as if cut in half... The plain steel armature is attracted when the coil is powered up, the one wrapped with the shorted coil is repelled. The fixed core provides a strong, static B-field for the armatures to act on. Ideally the throw isn't too long - 30-60mm depending on area is probably right.

The 'bias' permanent magnets are optional, and provide better response at low power, and make it all a bit more efficient.

The coil just has to saturate the 3 bits of steel - and it can do that with surprisingly little input power. Please see the thread I'm about to start on "Magnetic Field Equations Predict Overunity"... ;-)

The force you get between 2 magnets is proportional to the area of the facing sides * Bfield^2 / 2 * u0. So core face area matters a lot! You can also put big flat washers between the PMs & The steel on the shaft - to provide surface area on the outside of the coil too. This is often done with solenoids.

Anyway - according to my calcs this will make about 15 Horsepower at 1000rpm for a core diameter of 100mm and a throw of 40mm.

Electrical power required to saturate the iron cores? Perhaps 1000 amp-turns at most. Which we could provide with (far less than) 50 watts of input power...

Happy to go thru the calcs with folk...

[tinman]

Like this one in the video link
http://www.youtube.com/watch?v=tM_HRwqKzFk

[tim123]

Hi tinman. No it's not working on the same principles as the Gap-Power device. The only similarity is that they're both reciprocating engines.

[gotoluc]

Hi Tim,

thank you for taking the time to post this interesting variation of my design.

Would you not be able to also take advantage of the coils outside field like I demonstrated in my new video?

Are you able to build a prototype?... I could consider building a smaller version of it if that can help.

This is the kind of sharing I've been hoping for. It's been years since I started my Mostly Magnet Motor topic and you're the first to share a variation that could improve on what I have found.

Thanks for sharing

Luc

[tim123]

Hi Luc, yes you would be able to make use of the exterior field too. Both ends of the piston could have an exterior part too - like a washer, although if the coil itself was wrapped in steel the exterior flux would be negligible apart from right at the opening.

I've been working on the basis that the flux in the core of a solenoid is more or less constant throughout it's length - making the calcs easier. It's also by far the strongest flux. So if I can make it work just within the core - then that's at least a good start.

I think it was Wesley Gary who originally came up with the basic idea of using a coil & 2 opposing magnets - back in the 1800s. I saw your latest vid, and I was impressed. I think your design as it stands is a viable OU device - given scaling up and proper engineering.

I'm currently trying to turn my tumbledown barn into a decent workshop. Should be done next month. At which point I'll be getting it together to make prototypes, hopefully. According to my calcs, it would need a core diameter of min 60mm, and a length of 100-200mm to give OU, so a small prototype would probably be a waste of materials.

I'll send you a link to my coil calculator in a PM if you like... Not sure it's ready for the whole world yet ;-)