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Old 03-24-2006, 09:04 PM
  #473  
BATT_MAN
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Join Date: Nov 2005
Location: Colorado
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Quote:
Originally Posted by asw7576

FYI: kawada armatures have built in fan, it would be killer motors if team checkpoint is able to copy that.



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Fans require energy to move air. The energy used up by the fan is energy that can't be used to move your car forward.

My Wife's old Nissan Sentra was faster when you turned the A/C off...same concept.
A motorís armature develops torque. However, there is a difference between developed torque and shaft torque.

If the armature has a fan, the fan has to move air, and like Adrian said, it takes work and energy to move the air. This energy is taken away from the overall motor output.

Unless the fan does a SUBSTANTIAL BENEFIT in cooling the motor (which will not) the torque and power that the fan takes away from the motor is contra productive.

We have done tests with all kinds of air moving mechanisms inside motors and once you measure overall efficiency, power, and torque, we found most of them not to be beneficial. They are more for looks than anything else....

There are better ways to cool down the commutator, magnets, and brushes.

The "majority" of ths so called armature cooling fans do not work. They are more for looks....
The same goes to "some" of the aftermarket rings and heatsinks that attach to the armature.

When you attach anything to an armature, you change the moment of inertia of the armature and that affects the overall performance. The moment of inertia of the armature is one if the major factors that defines motor performance.
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