Axial flux actuators using printed circuit board armatures

1 . An energy conversion device, comprising:

at least a first magnet assembly in a fixed frame, the first magnet assembly including first magnets configured to generate first magnetic flux within an active region that extends along at least a portion of an annulus; and

a first printed circuit board (PCB) armature segment including at least a first winding configured to generate second magnetic flux within the active region, wherein:

the first PCB armature segment is configured and arranged so that the first winding can move, relative to the fixed frame, in an arcuate path about an axis of rotation;

radial edges of the first PCB armature segment subtend an angle of less than 360 degrees about the axis of rotation; and

a portion of the first PCB armature segment that extends radially outwardly of the portion of the annulus is attached to a mechanical load so that the mechanical load can be driven by movement of the first PCB armature segment relative to the fixed frame.

2 . The energy conversion device of claim 1 , wherein the first PCB armature segment is configured and arranged to rotate relative to the fixed frame about the axis of rotation.

3 . The energy conversion device of claim 2 , wherein the first magnet assembly includes a magnet assembly segment, wherein radial edges of the magnet assembly segment subtend an angle of less than 360 degrees.

4 . The energy conversion device of claim 2 , wherein:

the first magnets are configured to generate the first magnetic flux generally parallel to the axis of rotation; and

the first winding is configured and arranged to generate the second magnetic flux generally parallel to the axis of rotation.

5 . The energy conversion device of claim 1 , further comprising:

at least a first conductor in the fixed frame, the first conductor being electrically connected to the first winding to enable the first conductor to supply first current to the first winding to cause the first winding to generate the second magnetic flux.

6 . The energy conversion device of claim 5 , further comprising:

at least one power electronic circuit in the fixed frame, the at least one power electronic circuit being connected to the first conductor to supply the first current to the first conductor to cause the first winding to generate the second magnetic flux.

7 . The energy conversion device of claim 5 , further comprising:

at least one slip ring assembly configured and arranged to electrically connect the first conductor to the first winding while the first PCB armature segment rotates relative to the fixed frame.

8 . The energy conversion device of claim 5 , wherein the first conductor is a first cable that is directly connected to the first winding via a first terminal on the first PCB armature segment.

9 . The energy conversion device of claim 1 , further comprising:

a hub component supporting the first PCB armature segment; and

a bearing assembly mechanically connected to the hub component to enable the hub component to rotate relative to the fixed frame.

10 . The energy conversion device of claim 1 , wherein:

the first magnet assembly includes a first back iron and a first set of permanent magnets;

the energy conversion device further comprises a second magnet assembly including a second back iron and a second set of permanent magnets, the second back iron being oriented generally parallel to the first back iron; and

the first PCB armature segment is disposed in a gap between the first set of permanent magnets and the second set of permanent magnets.

11 . The energy conversion device of claim 1 , further comprising:

a housing supporting the first PCB armature segment and the first magnet assembly such that the first PCB armature segment is movable relative to the housing and the first magnet assembly is held stationary with respect to the housing.

12 . The energy conversion device of claim 1 , further comprising:

a second PCB armature segment configured to be independently movable relative to the first PCB armature segment and the fixed frame, the second PCB armature segment including at least a third winding configured to generate third magnetic flux within the active region, wherein radial edges of the second PCB armature segment subtend an angle of less than 360 degrees about the axis of rotation.

13 . The energy conversion device of claim 12 , wherein:

the first magnet assembly includes a first back iron and a first set of permanent magnets;

the energy conversion device further comprises a second magnet assembly including a second back iron and a second set of permanent magnets, the second back iron being oriented generally parallel to the first back iron; and

the first PCB armature segment and the second PCB armature segment are disposed in a same air gap between the first set of permanent magnets and the second set of permanent magnets.

14 . A method for operating an energy conversion device, the energy conversion device including at least a first magnet assembly having first magnets configured to generate first magnetic flux within an active region that extends along at least a portion of an annulus, and a first printed circuit board (PCB) armature segment having at least a first winding configured to generate second magnetic flux within the active region, wherein radial edges of the first PCB armature segment subtend an angle of less than 360 degrees about an axis of rotation and a portion of the first PCB armature segment that extends radially outwardly of the portion of the annulus is attached to a mechanical load, the method comprising:

while the first magnet assembly is stationary with respect to a fixed frame, energizing the first winding to cause the first PCB armature segment to move, relative to the first magnet assembly, in an arcuate path about the axis of rotation so that the mechanical load is driven by movement of the first PCB armature segment relative to the fixed frame.

15 . The method of claim 14 , wherein energizing the first winding causes the first PCB armature segment to rotate about the axis of rotation.

16 . The method of claim 14 , wherein the first magnet assembly includes a magnet assembly segment, wherein radial edges of the magnet assembly segment subtend an angle of less than 360 degrees.

17 . The method of claim 14 , further comprising:

the first magnets are configured to generate the first magnetic flux generally parallel to the axis of rotation; and

the first winding is configured and arranged to generate the second magnetic flux generally parallel to the axis of rotation.

18 . The method of claim 14 , further comprising:

supplying first current to at least a first conductor in the fixed frame, the first conductor being electrically connected to the first winding to cause the first winding to generate the second magnetic flux.

19 . The method of claim 18 , wherein supplying the first current to the first conductor includes:

operating at least one power electronic circuit in the fixed frame to supply the first current to the first conductor to cause the first winding to generate the second magnetic flux.

20 . The method of claim 19 , wherein the energy conversion device further includes at least one slip ring assembly that electrically connects the first conductor to the first winding while the first PCB armature segment moves relative to the first magnet assembly.

21 . The method of claim 19 , wherein the first conductor is a first cable that is directly connected to the first winding via a first terminal on the first PCB armature segment.

22 . The method of claim 14 , wherein the energy conversion device further includes:

a hub component supporting the first PCB armature segment; and

a bearing assembly mechanically connected to the hub component to enable the hub component to rotate relative to the first magnet assembly.

23 . The method of claim 14 , wherein:

the first magnet assembly includes a first back iron and a first set of permanent magnets;

the energy conversion device further comprises a second magnet assembly including a second back iron and a second set of permanent magnets, the second back iron being oriented generally parallel to the first back iron; and

the first PCB armature segment is disposed in a gap between the first set of permanent magnets and the second set of permanent magnets.

24 . The method of claim 14 , wherein the energy conversion device further includes:

a housing supporting the first PCB armature segment and the first magnet assembly such that the first PCB armature segment is movable relative to the housing and the first magnet assembly is held stationary with respect to the housing.

25 . The method of claim 14 , wherein the energy conversion device further includes a second PCB armature segment including at least a second winding configured to generate third magnetic flux within the active region, wherein radial edges of the second PCB armature segment subtend an angle of less than 360 degrees about the axis of rotation, and the method further comprises:

while the first magnet assembly is stationary with respect to the fixed frame, energizing the second winding to cause the second PCB armature segment to move, relative the first magnet assembly and independent of the first PCB armature segment, in an arcuate path about an axis of rotation.

26 . The method of claim 25 , wherein:

the first magnet assembly includes a first back iron and a first set of permanent magnets;

the energy conversion device further comprises a second magnet assembly including a second back iron and a second set of permanent magnets, the second back iron being oriented generally parallel to the first back iron; and

the first PCB armature segment and the second PCB armature segment are disposed in a same air gap between the first set of permanent magnets and the second set of permanent magnets.