Electric motor types

My opinion is hybrid is where it should be...

No experienced boater likes to play with vessel range and that is what electric does so well.

So, the best solution is to hybridize the system. Use electric when it is available and low power demands and use gasoline/other fuel when the electric is low and discharged. Trouble is cost.

But my boat would be great for hybrid system. When I am crusing slow or fishing, could be electric; if I want to haul or electric is low; gas kicks in. A bit like the hybrid car.

 

Using sails / solar for a sun -wind-Electric hybrid with flip down foils might be interesting, don't know if it has been seriously tried and ruled out..... Cost would be very high, but if it can be made self-sufficient for someone living full-time on the water, might be worth the cost?

 

This is a fantastic thread @gonzo ! Hat's off for starting the ball rolling.

 

Thanks. I am learning quite a bit too.

 

The Hall effect motor is rarely discussed and rather unusual in its operation. This thread died some time ago, as did interest in this motor. Since the thread is about motor types and lacking in variety, it seemed like a good place to bury it. The power was also well above the range most of us would ever need. I have seen only one very low power low speed example similar to the hall effect brake disc in an electric meter, and only one any description of a high power application. There is very little information available online and I don't feel much like digging through the engineering library down at the U.

Back around 1965 Marine Technology magazine ran an article on Hall effect motors for ship propulsion using turbine engines with electric motor generator drives. The advantage was the elimination of the mechanical transmission needed to get the huge reduction in rpm which provided a significant cost and weight savings and offered some flexibility with arrangement, The distance between the motor and generator were necessarily short due to the high current and conductor size. If I remember correctly, the motor and generator were also lighter and certainly simpler than the norm. The motor and generator rotors were solid steel cylinders with no rotating windings. The stators were pure DC coils, no switching. The generators ran at the speed of the turbines and the rotors ran at the propeller speed. It has been a few decades, so I can't provide numbers. These were intended for cargo ships, so the scale was massive. There were some photographs of a prototype that looked if not full scale, certainly very large. Since I read this around 1968, I can't quote exact numbers.

The voltage was low, the power was high and the current was extremely high. Sorry for the imprecise terminology. The biggest stumbling block was that they needed a liquid metal sleeve bearing to carry the current (and support the shaft?). The best they could come up with at the time was sodium potassium eutectic alloy which had the minor drawback of having to run in a perfectly dry nitrogen environment, which was a bit of a poser on a ship. Why they couldn't use mercury I can't recall. This was before the development of Galinstan, a Ga In Sn Zn alloy with a melting point of 8C and freezing point of -19C. The DSC plot looks like there is an unusual hysteresis rather than a wide liquidus to solidus range. Be that as it may, 8C is cool enough to avoid problems. It strikes me that if the hall effect drive could be made practical using a non-toxic, much less reactive alloy, the design could be resurrected.

 

Fascinating stuff

 

I had never heard about it.

 

I can't find a single word about Hall effect motors online, only Hall effect sensors for controlling brushless motor commutation. They are necessary for high torque/very low speed (like an electric vehicle in traffic) but all my model 'plane brushless motors and electric outboard motor are sensorless.

 

This morning I was watching a program on the solar system. A really interesting fact is that the gas giants have pressures of over 1 million bars. At that pressure Hydrogen becomes metallic. There is some research starting on the properties of materials at very high pressures. I think that new materials, superconductors and ultra-strong magnets may change the way we think of electric motors.

 

This concept is kind of interesting to me,

magnetic Wankel motor at DuckDuckGo https://duckduckgo.com/?t=h_&q=magnetic+Wankel+motor&iax=videos&ia=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DWwBglMinUvk

Seems to be powered through 90% or so of a revolution by magnetic repulsion, thus should be more efficient theoretically? It would require a starter motor and flywheel, as is the case for conventional IC engines. An electromagnet COULD BE timed to draw in and push out at the approximate 10% end of each rotation, as I understand it- instead of the mechanical arrangement. Design is probably way too heavy for propulsion purposes?

Ps. Not to be confused with perpetual motion claims!

 

I found the Hall effect article.

 

Hall effect sensors have been used in marine for longer than I've been around. Paddlewheel logs, ignition timing/crankshaft position sensors, oil injection pump sensors, and more that I will recall post-coffee.

 

Hybrid systems seem like the best of both worlds because of the back up system.
I have thought about add a thunder struck type system to a C30. Leaving the diesel in place while adding a gear and pillow blocks to the prop shaft. Part of the galleys draw cabinet would be sacrifice for the electric motor and reduction gear. It would be cheep and easy like every thing on a sailboat. What could go wrong?
Or I could just go sailing and maintain the existing diesel system as is. Fun to think about.
Toyota is going to a Ammonia-fuelled engines.

 

Hybrid in the form of an electric motor sailer does it for me where excess power goes into propulsion. Eventually we will have sufficient power available that the rag will be optional.

 

On a sailboat, a water generator would be the most efficient at charging batteries. It can take care of all the house electrical needs and maybe some leftover to run a propulsion motor occasionally. Of course a few days in the doldrums would force you to go on an energy savings schedule.