Permanent magnet d.c. motor having a radially-disposed working flux gap

A. d.c. motor, comprising:

• a base structure having a motor axis;
• a motor shaft supported upon said base structure co-axially with said motor axis;
• a stator assembly including a plurality of upstanding spaced apart core components each with a plurality of laminations radially stacked from first to last in succeeding mutual adjacency outwardly from and generally parallel with said motor axis, each said core component having a pole piece region of predetermined pole height with a first flux interaction surface radially outwardly facing from said motor axis located radially next outwardly from said motor shaft and generally coextensive with said last of said radially stacked laminations along said pole height, each said core component having a winding association region extending from said pole piece region and supported at said base structure, said stator assembly including field windings, each extending around one of said core components at said winding association region to define a stator winding of stator winding height and selectively excitable to generate electromagnetic flux at said first flux interaction surface;
• a rotor positioned upon said motor shaft and rotatable about said motor axis;
• a permanent magnet assembly, including magnet pole components generally configured as a ring, supported by said rotor for rotation about said motor axis and located next outwardly radially from said first flux interaction surface, said magnet components having a second flux interaction surface parallel with said motor axis, substantially coextensive with said pole height distance of said first flux interaction surface, and selectively magnetized to define magnetic pole segments having north and south pole components of thickness, L.sub.m, disposed radially with respect to said motor axis;
• a magnetically permeable back component supported by said rotor and positioned in magnetic flux path completing adjacency with said magnetic components at a location next outwardly radially therefrom;
• and
• said first and second flux interaction surfaces being radially spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio L.sub.m /L.sub.g, of value greater than about 3.

A d.c. motor, comprising:

• a base structure having a motor axis;
• a motor shaft supported upon said base structure coaxially with said motor axis;
• a rotor supported upon said motor shaft and rotatable about said motor axis;
• a magnetically permeable back component supported with said rotor at a location next radially outwardly from said motor shaft;
• a permanent magnet component generally configured as a ring, supported by said rotor next radially outwardly from and in flux path defining adjacency with said back component, having a first flux interaction surface of predetermined magnet extent parallel with said motor axis, selectively magnetized to define magnetic pole segments having north and south magnetic pole components of thickness, L.sub.m, disposed radially with respect to said motor axis;
• a stator assembly including upstanding spaced apart core components each with a plurality of laminations radially stacked from first to last in succeeding mutual adjacency outwardly and generally parallel with said motor axis, each said core component having a pole piece region of pole height extending to a pole tip and substantially coextensive with said predetermined magnet extent with a second flux interaction surface inwardly facing toward said motor axis located radially next outwardly from said permanent magnet component, each said core component having a winding association region extending from said pole piece region and supported at said base structure, said stator assembly including field windings, each extending around one of said core components at said winding association region to define a stator winding of stator winding height and selectively excitable to generate electromagnetic flux at said second flux interaction surface;
• and
• said first and second flux interaction surfaces being spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio in L.sub.m /L.sub.g, of value greater than about 3.

A d.c. motor comprising:

• a base structure having a motor axis and extending radially outwardly therefrom to an annular stator assembly mounting portion at least a portion of which is configured as a mounting cavity;
• a stator assembly including a plurality of upstanding, spaced apart core components supported along a circular locus at said mounting portion, each with a plurality of laminations radially stacked with surfaces in succeeding mutual adjacent outwardly from said motor axis and arranged generally parallel with said motor axis, each said core component having a winding association region extending within said mounting cavity and a pole piece region extending therefrom a pole height distance with a first flux interaction surface generally coextensive with said surfaces of said stacked laminations along said pole height distance, and a field winding extending around a said core component at said winding association region to define a stator winding of stator winding height and selectively excitable to generate electromagnetic flux at said pole piece regions to generate a rotating magnet field, at least a portion of said field winding being supportably stabilized by a surmounting thermally conductive, electrically insulative material located within said mounting cavity;
• a rotor, rotatable about said motor axis and having a central region extending to a generally peripherally disposed magnet support portion;
• and
• a permanent magnet assembly, including magnet pole components generally configured as a ring, supported by said rotor at said magnet support portion, having a second flux interaction surface generally parallel with said motor axis, generally coextensive with said pole height distance of each said pole piece region and in adjacency with said first flux interaction surface, and selectively magnetized to define magnetic pole segments having north and south pole components of thickness, L.sub.M, disposed radially with respect to said motor axis.

A d.c. motor, comprising:

• a base structure having a motor axis and extending radially outwardly therefrom to a stator assembly mounting portion;
• a stator assembly including a plurality of upstanding spaced apart core components supported at said mounting portion generally parallel with said motor axis, each having a winding association region and a pole piece region extending therefrom a pole height distance with a first flux interaction surface, and a field winding extending around said core component at said winding association region to define a stator winding of stator winding height located below said pole piece region and selectively excitable to generate electromagnetic flux at said first flux interaction surface;
• a rotor, rotatable about said motor axis;
• a permanent magnet assembly, including a magnet component generally configured as a ring, supported by said rotor for rotation about said motor axis, having a second flux interaction surface generally parallel with said motor axis, coextensive and in adjacency with said first flux interaction surface, and selectively radially magnetized to define magnetic pole segments having north and south pole components of thickness, L.sub.m, disposed radially with respect to said motor axis;
• said first and second flux interaction surfaces being spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio, L.sub.m /L.sub.g, of value greater than about 3;
• wherein said rotor has a central region extending to a generally peripherally disposed magnet support portion;
• and
• said rotor magnet support portion being configured to exhibit a stiffness to radially imposed force thereat and a flexibility only at a location in spaced adjacency with said core components to vector forces generated parallel to said mor axis effective to substantially avoid audible noise generating flexure at said rotor central region.

A d.c. motor, comprising:

• a base structure having a motor axis and extending radially outwardly therefrom to a stator assembly mounting portion;
• a stator assembly including a plurality of upstanding spaced apart core components supported at said mounting portion generally parallel with said motor axis, each having a winding association region and a pole piece region extending therefrom a pole height distance with a first flux interaction surface, and a field winding extending around said core component at said winding association region to define a stator winding of stator winding height located below said pole piece region and selectively excitable to generate electromagnetic flux at first flux interaction surface;
• a rotor, rotatable about said motor axis;
• a permanent magnet assembly, including a magnet component generally configured as a ring, supported by said rotor for rotation about said motor axis, having a second flux interaction surface generally parallel with said motor axis, coextensive and in adjacency with said first flux interaction surface, and selectively radially magnetized to define magnetic pole segments having north and south pole components of thickness, L.sub.m, disposed radially with respect to said motor axis;
• said first and second flux interaction surfaces being spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio, L.sub.m /L.sub.g, of value greater than about 3;
• said stator assembly core components being supported at said mounting position to locate said first flux interaction surface radially inwardly facing toward said motor axis;
• said permanent magnet assembly magnetic component being positioned upon said rotor to locate said second flux interaction surface to face radially outwardly from said motor axis;
• including a magnetically permeable back component supported by said rotor and positioned in magnetic flux path completing adjacency with said permanent magnet assembly opposite said second flux interaction surface;
• and
• including a housing component positioned over said rotor, connected with said base structure, and configured to support said stator assembly core components at said flux interaction region at a location opposite said first flux interaction surface.

A d.c. motor, comprising:

• a base structure having a motor axis and extending radially outwardly therefrom to a stator assembly mounting portion;
• a stator assembly including a plurality of upstanding spaced apart core components supported at said mounting portion generally parallel with said motor axis, each having a winding association region and a pole piece region extending therefrom a pole height distance with a first flux interaction surface, and a field winding extending around said core component at said winding association region to define a stator winding of stator winding height located below said pole piece region and selectively excitable to generate electromagnetic flux at said first flux interaction surface;
• a rotor, rotatable about said motor axis;
• a permanent magnet assembly, including a magnet component generally configured as a ring, supported by said rotor for rotation about said motor axis, having a second flux interaction surface generally parallel with said motor axis, coextensive and in adjacency with said first flux interaction surface, and selectively radially magnetized to define magnetic pole segments having north and south pole components of thickness, L.sub.m, disposed radially with respect to said motor axis;
• said first and second flux interaction surfaces being spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio, L.sub.m /L.sub.g, of value greater than about 3;
• and
• including a circuit board mounted about said base structure, having an array of openings therein located over and aligned with said stator assembly mounting portion, each said opening being configured to receive and support one of said core components at said pole piece region adjacent said winding association region.

A d.c. motor, comprising:

• a base structure having a motor axis;
• a motor shaft supported upon said base structure coaxially with said motor axis;
• a rotor supported upon said motor shaft and rotatable about said motor axis;
• a magnetically permeable back component supported with said rotor at a location next radially outwardly from said motor shaft;
• a permanent magnet component generally configured as a ring, supported by said rotor next radially outwardly from and in flux path defining adjacency with said back component, having a first flux interaction surface of predetermined magnetic extent parallel with said motor axis, selectively magnetized to define magnetic pole segments having north and south magnetic pole components of thickness, L.sub.M, disposed radially with respect to said motor axis;
• a stator assembly including vertical core components having a pole piece region of pole height extending to a pole tip and substantially coextensive with said predetermined magnet extent with a second flux interaction surface inwardly facing toward said motor axis located radially next outwardly from said permanent magnet component, each said core component having a winding association region extending from said pole piece region and supported at said base structure, said stator assembly including field windings, each extending about one of said core components at said winding association region to define a stator winding of stator winding height and selectively excitable to generate electromagnetic flux at said second flux interaction surface;
• said first and second flux interaction surfaces being spaced apart to define a flux working gap of radial length, L.sub.g, having a gap radius, R.sub.G, extending from the center thereof to said motor axis, and defining a ratio L.sub.m /L.sub.g, of value greater than about 3;
• and
• including a housing component positioned over said rotor, connected with said base structure, and configured to support said stator assembly core components at said pole tip in close adjacency with said permanent magnet component.

A d.c. motor comprising:

• a base structure having a motor axis and extending radially outwardly therefrom to an annular stator assembly mounting portion at least a portion of which is configured as a mounting cavity;
• a stator assembly including a plurality of upstanding, spaced apart core components supported along a circular locus at said mounting potion generally parallel with said motor axis, each having a winding association region extending within said mounting cavity and a pole piece region extending therefrom a pole height distance with a first flux interaction surface, and a field winding extending around a said core component at said winding association region to define a stator winding of stator winding height and selectively excitable to generate electromagnetic flux at said first flux interaction surface, at least a portion of said field winding being supportably stabilized by a surmounting thermally conductive, electrically insulative material located within said mounting cavity;
• a rotor, rotatable about said motor axis and having a central region extending to a generally peripherally disposed magnet support portion;
• a permanent magnet assembly, including a magnet component generally configured as a ring, supported by said rotor at said magnet support portion, having a second flux interaction surface generally parallel with said motor axis, coextensive and in adjacency with said first flux interaction surface, and selectively radially magnetized to define magnetic pole segments having north and south pole components;
• and
• said rotor magnet support portion being configured to exhibit a stiffness to radially imposed force thereat and a flexibility to vector forces applied parallel to said motor axis effective to substantially avoid audible noise generating flexure at said rotor central region.