PERMANENT MAGNET ASSEMBLIES FOR A CYLINDER OF AN ELECTRICAL MACHINE
A rotor sub-assembly for an electrical machine comprises a rotor hub. The rotor hub may comprise a multi-faceted surface comprising a plurality of facets extending along a perimeter of the rotor hub. Each facet of the multi-faceted surface may comprise a substantially planar surface that is oriented substantially perpendicular to a radial line extending from an approximate center of the rotor hub. A plurality of permanent magnet assemblies is disposed circumferentially around the multi-faceted surface. Each of the permanent magnet assemblies is singularly affixed to a corresponding facet of the multi-faceted surface and comprises exactly one of: a first permanent magnet polarized in a direction substantially orthogonal to the planar surface of the corresponding facet onto which a particular permanent magnet assembly comprising the first permanent magnet is coupled; or a second magnet of the particular permanent magnet assembly polarized in a direction substantially parallel to the planar surface of the corresponding facet to which to which the particular permanent magnet assembly is coupled; or a combination of the first permanent magnet and the second permanent magnet.
1 . A rotor sub-assembly for an electrical machine, comprising:
a rotor hub comprising a multi-faceted surface comprising a plurality of facets extending along a perimeter of the rotor hub, wherein each facet of the multi-faceted surface comprises a substantially planar surface that is oriented substantially perpendicular to a radial line extending from an approximate center of the rotor hub;
a plurality of permanent magnet assemblies disposed circumferentially around the multi-faceted surface, wherein each of the permanent magnet assemblies is singularly affixed to a corresponding facet of the multi-faceted surface and comprises exactly one of:
a first permanent magnet polarized in a direction substantially orthogonal to the planar surface of the corresponding facet onto which a particular permanent magnet assembly comprising the first permanent magnet is coupled, or
a second magnet of the particular permanent magnet assembly polarized in a direction substantially parallel to the planar surface of the corresponding facet to which to which the particular permanent magnet assembly is coupled, or
a combination of the first permanent magnet and the second permanent magnet.
2 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the multi-faceted surface comprises multiple layers of facets disposed axially along an outer surface of the rotor hub.
3 . The rotor sub-assembly for the electrical machine of claim 2 , wherein at least one of the multiple layers of facets is rotationally shifted relative to an adjacent layer.
4 . The rotor sub-assembly for the electrical machine of claim 1 , further comprising a magnet retention sleeve disposed around outer edges of the plurality of permanent magnet assemblies.
5 . The rotor sub-assembly of claim 1 , wherein the particular permanent magnet assembly comprises an approximately planar surface affixed to the corresponding facet of the multi-faceted surface.
6 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the rotor hub comprises one facet per pole.
7 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the particular permanent magnet assembly comprises an approximately rectangular prism shape.
8 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the multi-faceted surface is disposed along an exterior perimeter of the rotor hub.
9 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the multi-faceted surface is disposed along an interior perimeter of the rotor hub.
10 . The rotor sub-assembly for the electrical machine of claim 1 , wherein the plurality of facets comprise at least a first facet and a second facet, the first facet having a first chord length and the second facet having a second chord length, the first chord length being different from the second chord length.
11 . An electrical machine comprising:
a stator;
a rotor hub comprising a multi-faceted surface comprising a plurality of facets extending along a perimeter of the rotor hub, wherein each facet of the multi-faceted surface comprises a substantially planar surface that is oriented substantially perpendicular to a radial line extending from an approximate center of the rotor hub;
a plurality of permanent magnet assemblies disposed circumferentially around the multi-faceted surface, wherein each of the permanent magnet assemblies is singularly affixed to a corresponding facet of the multi-faceted surface and comprises exactly one of:
a first permanent magnet polarized in a direction substantially orthogonal to the planar surface of the corresponding facet onto which a particular permanent magnet assembly comprising the first permanent magnet is coupled, or
a second magnet of the particular permanent magnet assembly polarized in a direction substantially parallel to the planar surface of the corresponding facet to which to which the particular permanent magnet assembly is coupled, or
a combination of the first permanent magnet and the second permanent magnet.
12 . The electrical machine of claim 11 , wherein every permanent magnet assembly of the plurality of permanent magnet pole segments comprises approximately the same dimensions.
12 . The electrical machine of claim 11 , wherein the multi-faceted surface comprises multiple layers of facets disposed axially along an outer surface of the rotor hub.
14 . The electrical machine of claim 11 , wherein the rotor hub comprises a total number of facets disposed on a layer of the multiple layers of facets equal to a total number of poles of the rotor hub.
15 . The electrical machine of claim 11 , wherein the plurality of facets comprise at least a first facet and a second facet, the first facet having a first chord length and the second facet having a second chord length, the first chord length being different from the second chord length.
16 . The electrical machine of claim 10 , wherein the particular permanent magnet assembly comprises an approximately rectangular prism shape.
17 . A rotor sub-assembly of an electrical machine, comprising:
a multi-faceted rotor hub comprising a plurality of facets extending along a perimeter of the rotor hub, wherein each facet of the multi-faceted surface comprises a substantially planar surface that is oriented substantially perpendicular to a radial line extending from an approximate center of the rotor hub;
a plurality of permanent magnet assemblies disposed circumferentially around the multi-faceted surface, wherein each of the permanent magnet assemblies is singularly affixed to a corresponding facet of the multi-faceted surface and comprises exactly one of:
a first permanent magnet polarized in a direction substantially orthogonal to the planar surface of the corresponding facet onto which a particular permanent magnet assembly comprising the first permanent magnet is coupled, or
a second magnet of the particular permanent magnet assembly polarized in a direction substantially parallel to the planar surface of the corresponding facet to which to which the particular permanent magnet assembly is coupled, or
a combination of the first permanent magnet and the second permanent magnet.
18 . The rotor sub-assembly of claim 17 , wherein every permanent magnet assembly of the plurality of permanent magnet assemblies comprises approximately the same dimensions.
19 . The rotor sub-assembly of claim 17 , wherein the plurality of facets comprise at least a first facet and a second facet, the first facet having a first chord length and the second facet having a second chord length, the first chord length being different from the second chord length.
20 . The rotor sub-assembly of claim 17 , wherein the rotor hub comprises a total number of facets disposed on a layer of the multiple layers of facets equal to twice a total number of poles of the rotor hub.