Cooling of Contra- rotating Motor

[bhaazee]

For contra-rotating motor, the external rotating element is a cylinder that carries copper coil and on account of electrical resistance, the coil is getting heated. The generated heat can be removed only by circulating oil around the coil through cavities/vents available inside the cylinder that holds the copper coil. However, as both the stator and rotor are rotating how can the oil be carried into and out of the cavities? any Idea?

Regards.

 

[Danger]

I've never heard of a contra-rotating motor, and can't for the life of me think of any reason to build one. If torque control is a problem, that's what counter-weights are for.

 

[bhaazee]

k fine. You can even assume this for a generator and contra-rotating generators are available.

 

[AlephZero]

I've never heard of a contra-rotating motor, and can't for the life of me think of any reason to build one.

Contra rotation cancels the gyroscopic effects. Some military jet engines have contra rotating shafts for that reason. It can also save a set of stator vanes between the contra-rotating turbines, which is a nice bonus.

But the only contra-rotating electric motors and generators that I found on Google are small motors intended for model aircraft, or "experimental" generator designs for wind turbines - nothing big enough to need oil cooling.

 

[bhaazee]

The so called experimental wind turbines with contra-rotating generators (with dual propellers) are 100 KW models as I believe. This obviously needed liquid cooling process. But unable to find the cooling mechanism.

 

[AlephZero]

This obviously needed liquid cooling process.

Why would you want to use liquid cooling, when you have an unlimited supply of cooling AIR available? There are commercial air-cooled wind turbine designs up to 1.5MW. Even above that power, the idea of immersing large rotating components in liquid coolant doesn't seem like a good idea, except for oil-filled gearboxes where the oil has another function apart from cooling.

 

[bhaazee]

Consider a 2 MW wind turbine.Assuming its an Off-shore turbine, heat removal by air cooling will probably not be recommended. Assume a wind turbine in Sahara (50°C) Probably will make no sense to cool by air. Just an example.

Back to my query, I am trying in particular for some liquid cooling solutions.

May be some liquid cooling solutions are already available for my defined problem. However, unfortunately I am not able to catch those specific technical words to google it.

 

[AlephZero]

Sorry, but if you are jumping between motor and a generator, 100kW and 2MW power, and from offshore to a hot desert envioronment, I don't have any idea what your "defined" problem really is, except that you seem insistent on liquid cooling it.