An old method they used on the brushed motors from not too long ago. Less the silicone compound it's not so efficient. This is the first time I've heard of using it and congratulations a great idea but if I may add, remove the unit, clean the silicone off and replace it when cracks are seen or pieces are falling away. Time can dry it out and possibly lose it's heat transfer ability. Vibration would assist in contact being lost.

With the advent of super powered brushless monsters I have in a number of my boats the motor cooling was achieved with water jackets which did an excellent job as the water actually came into contact with the  motor's casing. Both ends sealed with an appropriate O ring. The interior of the jacket has small specially designed grooves cut into the casing which disrupts the water's passage through the jacket. This stops the water simply going in one side and being ejected immediately from the outlet.

The biggest problem was the ESC. After a few 200 amp units decided to burn out I stripped the heatshrink and used a waterproof sealant over the complete unit and fitted an oversized cooling plate using silicone between the two, then a cut to size aluminium heatsink using more silicone then a CPU cooling fan on the top, using more silicone. The fan was used due to the interior of the boat being an airtight/watertight compartment and it moved the air around  sufficiently to aid the cooling. It was run from an old 3s lipo which would last a complete day's racing before needing a recharge.

One factor I always consider today is a dual water pickup. Twice I have suffered damage from the inlet being blocked by debris so along with the rudder pickup I also use a transom pickup. Both are fed into a y connector which gives redundancy plus the pressure from the single pickup will also blow the debris from the other. I use thick walled nylon tubing to feed the ESC, front motor mount, motor water jacket and then it's disposed of via an outlet just below the upper deck joint. I purposely set the outlet higher as it's easier to spot on the down run. A healthy jet or water shows the system is working well. It sounds like overkill and to a degree is, but when racing the motor's throttle is stuck to wide open even on turns, depending on the course. It's enough work handling the boat without having to worry about cooling. A spotter is often used to check the outlet on each lap.

The extra weight of the cooling system is a small disadvantage and in a few instances has aided certain hulls to a better dryer ride. On a few occasions the hull has turned turtle and the sheer speed has ripped the canopy from it seating. By using conformal spray for waterproofing the boat can be resealed and continue immediately. In fact the ESC will actually still operate under water the sealing is so good.

BUT a BIG word of warning. Use the spray outside with a fan blowing the fumes away from you. They are absolutely lethal. On my first try I had the windows open and a large fan turning. My wife found me passed out after only a minute of starting to spray. I came too OK but had a bad headache for hours after.

Again, please excuse the interuption, maybe someone may find it useful.   Stu

But Krishna, Yoke is with Permanent magnets and coils are inside.
Of course we can make heat flow better by keeping yoke temp low.
But Heat flow from armature to sink (body) is limited by Brass Bush.

That is why BL Motors axle are so large of aluminium for heat flow and mounts are designed for heat sink.

Undoubtedly this is a brilliant and innovative idea, but brushed motors are structurally weak in heat flow. Better connect small fins on commutator that axially flow air through conductor segments of armature at high speed and flow hole in brush assembly and on reverse side too. Though air, but still be cooled directly cool the armature, the main culprit for I²Rt heat.

That is

hello sir how to you make boat prop please put that also iwant to make it

really great sir i wonder if you have any similar technique to cool the car motor.