Tesla-Dobrovolsky AC motor:
Tesla failed to design effective asynchronous
motor and Dobrovolsky resolved the problem
quite unsatisfactory: Tesla's genuine design is
consisted of one big thin rotor and Dobrovolsky
resolved the problem by attaching many small rotors mutually electrically insulated on a same shaft on identical way as rotor in the brush DC
motor.
By this design the eddy current is effectively
attenuated simultaneously with the torque
because eddy current produces the torque in
AC motor contrary to DC one where it
produces only thermal loss, making such AC
motor very weak in comparison to brush DC
motor.
This Dobrovolsky's improvement is among the
most persistent technical blunders still present
in the design of many AC motors, but the
solution was the best that those time could offer. Effective improvement is simple and yet effective:
it is consisted of improvement of layers' orientation
and specialization of magnetic and conductive
layers.
It is 3D: click it with mice to rotate
and roll the middle button to zoom.