Motor with composite housing

1. An apparatus comprising:

a first member comprising a shell that forms an exterior surface of a housing for a motor assembly;

a drive shaft extending longitudinally through the first member, the drive shaft being rotatable relative to the first member; and

a soft magnetic material formed onto the first member by spray deposition of a magnetic material, the magnetic material being bonded to an inner portion of the shell, the inner portion of the shell comprising a recessed surface defining a cavity, the recessed surface extending continuously around the inner portion of the shell and being equidistant in radial directions from the drive shaft;

wherein the soft magnetic material comprises particles of an iron-containing material built up by a continuous deposition of the particles, each particle having an aluminum oxide coating thereon, a plurality of the particles forming an aggregate of small micro-domains, the micro-domains being separated by oxide insulation boundaries, the soft magnetic material providing a magnetic path that limits losses associated with the formation of eddy currents in the soft magnetic material, and the oxide insulation boundaries limiting electrical conductivity; and

wherein the iron-containing material comprises an iron-aluminum alloy comprising about 89 wt. % iron, about 10 wt. % aluminum, and about 0.25 wt. % carbon; and

wherein the oxide insulation boundaries are aluminum oxide.

2. The apparatus of claim 1 , wherein the first member comprises a mold sleeve that forms an inner surface of a housing for a motor assembly.

3. The apparatus of claim 1 , wherein the iron-containing material further comprises cobalt, molybdenum, nickel, silicon, or a combination of at least two of the foregoing materials.

4. A motor assembly, comprising:

a composite housing having,

a shell,

a core of sprayed magnetic particles bonded to an inner-facing surface of the shell and forming a stator,

a recess in the inner-facing surface of the shell, the recess defining a cavity in the inner-facing surface, and

a winding on the core; and

a rotor having a magnet located thereon, the rotor being rotatably mounted within the winding and having an output shaft;

wherein a surface of the cavity defined by the recess extends longitudinally along a length of the shell and continuously around a cross section of the shell and is equidistant in radial directions from the output shaft;

wherein the core of sprayed magnetic particles comprises particles of an iron-containing material built up by a continuous deposition of the particles, each particle having an aluminum oxide coating thereon such that when deposited a plurality of the particles forms an aggregate of small micro-domains, each of the aggregates separated by oxide insulation boundaries, the iron-containing material providing a magnetic path that limits losses associated with the formation of eddy currents in the core, and the oxide insulation boundaries limiting electrical conductivity; and

wherein the iron-containing material comprises an iron-aluminum alloy comprising about 89 wt. % iron, about 10 wt. % aluminum, and about 0.25 wt. % carbon; and

wherein the oxide insulation boundaries are aluminum oxide.

5. The motor assembly of claim 4 , wherein the core of sprayed magnetic particles is formed in the recess.

6. The motor assembly of claim 4 , wherein the composite housing further comprises a mold sleeve having an outer-facing surface on which the core of the sprayed magnetic particles is formed.

7. The motor assembly of claim 6 , further comprising a hole in the core, the hole being configured to receive a fastener for coupling an additional element to the core.

8. The motor assembly of claim 7 , further comprising an insert in the hole in the core, the insert being configured to receive a fastener.

9. The motor assembly of claim 4 , wherein the iron-containing material further comprises cobalt, molybdenum, nickel, silicon, or a combination of at least two of the foregoing materials.