Electric machine

1. An interior permanent magnet electric machine, said machine comprising:

a rotor having a rotor shaft center and a circumference and comprising a plurality of radially placed magnets each aligned along a ray extending from the rotor shaft center toward the rotor circumference and having a proximal end closest the rotor shaft center and a distal end closest the rotor circumference, wherein each magnet comprises a plurality of magnetic segments and wherein a magnetic segment closest the distal end comprises a bonded magnetic material having a first electrical resistivity and a magnet segment closest the proximal end comprises a sintered magnetic material having a second electrical resistivity lower than the first electrical resistivity.

2. The interior permanent magnet electric machine of claim 1 , wherein the magnets establish a magnetic flux field in a circumferential direction of the rotor.

3. The interior permanent magnet electric machine of claim 1 , further comprising an electrical insulation disposed between adjacent magnetic segments.

4. The interior permanent magnet electric machine of claim 1 , wherein at least one of the plurality of magnets comprises a plurality of contiguous magnetic segments, each comprising a sintered magnetic material.

5. The interior permanent magnet electric machine of claim 4 , wherein a magnetic segment comprising sintered magnetic material has an electrical resistivity that lies within a range from about 1.2 microohm meter to about 1.6 microohm meter.

6. The interior permanent magnet electric machine of claim 1 , wherein at least one of the plurality of magnets comprises a plurality of contiguous magnetic segments, each comprising a bonded magnetic material.

7. The interior permanent magnet electric machine of claim 6 , wherein a magnetic segment comprising bonded magnetic material has an electrical resistivity of up to about 20 micro ohm meter.

8. The interior permanent magnet electric machine of claim 1 , wherein the machine comprises a multi-phase machine.

9. The interior permanent magnet electric machine of claim 1 , wherein each of the plurality of magnets independently comprise a permanent magnetic material.

10. The interior permanent magnet electric machine of claim 9 , wherein the permanent magnetic material comprises a compound comprising a rare earth atom.

11. The interior permanent electric magnet machine of claim 9 , wherein the permanent magnetic material comprises neodymium iron boron or samarium cobalt.

12. An interior permanent magnet machine, said machine comprising:

a rotor having a rotor shaft center and a circumference and comprising a plurality of radially placed magnets each aligned along a ray extending from the rotor shaft center toward the rotor circumference and having a proximal end closest the rotor shaft center and a distal end closest the rotor circumference, wherein each magnet comprises a plurality of magnetic segments and wherein a magnetic segment closest the distal end comprises a bonded magnetic material having a first electrical resistivity and a magnet segment closest the proximal end comprises a sintered magnetic material having a second electrical resistivity lower than the first electrical resistivity; and

a stator, wherein a magnetic flux field produced within the stator due to the plurality of magnets, is bidirectional.

13. The interior permanent magnet electric machine of claim 12 , wherein the plurality of magnets each comprise a plurality of contiguous magnetic segments comprising a sintered magnetic material.

14. The interior permanent magnet electric machine of claim 13 , wherein the plurality of magnets each further comprise a plurality of contiguous magnetic segments comprising a bonded magnetic material.

15. The interior permanent magnet electric machine of claim 12 , further comprising an electrical insulation disposed between adjacent magnetic segments.