Synchronous Torque
The unlike poles of the stator rotating
magnetic field and of the rotor lock together and
operate simultaneously. Figure 29 represents
conditions of a typical motor at no load, rotating in
a counter-clockwise direction. The South pole, S,
of the rotor is directly opposite the North pole, N,
of the stator. At that point all torques are zero.
However, at any displacement from that position,
as with the rotor pole dropping back to the
position S', a resultant torque along curve C will
be developed. This is the resultant of torque
curves A and B.