Electric motor with active hysteresis-based control of winding currents and/or having an efficient stator winding arrangement and/or adjustable air gap

A stator for an axial flux motor powered using three phases of electrical current, said stator comprising:

• a series of stator windings, the series being arranged in a circle which defines a circumference of the stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said three phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments;
• wherein each arc section is associated with a respective one of said three phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein said serpentine-shaped conductors in each arc segment are stacked upon one another with an electrically insulative material disposed therebetween, each arc segment including a stack of said serpentine-shaped conductors, each stack including:
• a first set of substantially identical serpentine-shaped conductors stacked alternatingly through the stack, and
• a second set of serpentine-shaped conductors sandwiched between the serpentine-shaped conductors of the first set, said second set of serpentine-shaped conductors being substantially identical to one another but different from said first set in that, when said first and second sets are alternatingly stacked, portions of said serpentine-shaped conductors in the first set which are outside of said slots extend around opposites sides of said teeth from portions of said serpentine-shaped conductors of the second set which are also outside of said slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• a first stator including a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein said serpentine-shaped conductors in each arc segment are stacked upon one another with an electrically insulative material disposed therebetween, each arc segment including a stack of said serpentine-shaped conductors, each stack including:
• a first set of substantially identical serpentine-shaped conductors stacked alternatingly through the stack, and
• a second set of serpentine-shaped conductors sandwiched between the serpentine-shaped conductors of the first set, said second set of serpentine-shaped conductors being substantially identical to one another but different from said first set in that, when said first and second sets are alternatingly stacked, portions of said serpentine-shaped conductors in the first set which are outside of said slots extend around opposites sides of said teeth from portions of said serpentine-shaped conductors of the second set which are also outside of said slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• a first stator including a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• a second stator on an opposite side of said rotor from said first stator, said second stator being arranged so as to constitute a mirror image of the first stator;
• and
• an annular stator core in each stator, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein said serpentine-shaped conductors in each arc segment are stacked upon one another with an electrically insulative material disposed therebetween, each arc segment including a stack of said serpentine-shaped conductors, each stack including:
• a first set of substantially identical serpentine-shaped conductors stacked alternatingly through the stack, and
• a second set of serpentine-shaped conductors sandwiched between the serpentine-shaped conductors of the first set, said second set of serpentine-shaped conductors being substantially identical to one another but different from said first set in that, when said first and second sets are alternatingly stacked, portions of said serpentine-shaped conductors in the first set which are outside of said slots extend around opposites sides of said teeth from portions of said serpentine-shaped conductors of the second set which are also outside of said slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• a first stator including a series of stator windings, the series of stator windings being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section, said first stator is axially spaced from said rotor to define a first air gap therebetween;
• a second stator on an opposite side of said rotor from said first stator at a second air gap, said second stator being arranged so as to constitute a mirror image of the first stator, said second stator is axially spaced from said rotor to define a second air gap therebetween;
• a first mechanism for varying said first air gap, said first stator being selectively movable in an axial direction from said rotor to vary said first air gap;
• a second mechanism for varying said second air gap, said second stator being selectively movable in said axial direction from said rotor to vary said second air gap;
• and
• a coupling mechanism for coupling actuation of said first mechanism to actuation of said second mechanism, so that variations in said first air gap produce substantially identical variations in said second air gap;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• and
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• and
• a first stator is axially spaced from said rotor to define a first air gap therebetween, said first stator being selectively movable in an axial direction from said rotor to vary said first air gap;
• and
• a second stator on an opposite side of said rotor from said first stator, said second stator being arranged so as to constitute a mirror image of the first stator, said second stator is axially spaced from said rotor to define a second air gap therebetween, said second stator being selectively movable in said axial direction from said rotor to vary said second air gap;
• each said first and second stators including:
• a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase, the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section, and a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by conductive material extending through said slots and around said teeth;
• wherein portions of said conductive material which are located outside of said slots have a larger cross sectional area than a radial width of one portion of the conductive material located in the slots, each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase, and said difference between said inter-phase separation space and said intra-phase separation space corresponds to a difference in phase.

A stator for an axial flux motor powered using at least two phases of electrical current, said stator comprising:

• a series of stator windings, the series being arranged in a circle which defines a circumference of the stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments, each serpentine conductor having a uniformed height;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein portions of said serpentine-shaped conductors which are located outside of said slots have a larger cross sectional area and width in the radial direction than a circumferential width of a portion of one of the serpentine-shaped conductors which are located in the slots.

A stator for an axial flux motor powered using three phases of electrical current, said stator comprising:

• a series of stator windings, the series being arranged in a circle which defines a circumference of the stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said three phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any give instant of time during current flow, alternates in direction along a length of each arc section;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments, each serpentine conductor having a uniformed height;
• wherein each arc section is associated with a respective one of said three phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein portions of said serpentine-shaped conductors which are located outside of said slots have a larger cross sectional area and width in the radial direction than a circumferential width of a portion of one of the serpentine-shaped conductors which are located in the slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• a first stator including a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments, each serpentine conductor having a uniformed height;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein portions of said serpentine-shaped conductors which are located outside of said slots have a larger cross sectional area and width in the radial direction than a circumferential width of a portion of one of the serpentine-shaped conductors which are located in the slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• a first stator including a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• a second stator on an opposite side of said rotor from said first stator, said second stator being arranged so as to constitute a mirror image of the first stator;
• and
• an annular stator core in each stator, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator winding being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments, each serpentine conductor having a uniformed height;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• wherein portions of said serpentine-shaped conductors which are located outside of said slots have a larger cross sectional area and width in the radial direction than a circumferential width of a portion of one of the serpentine-shaped conductors which are located in the slots.

An axial flux motor powered using at least two phases of electrical current, said axial flux motor comprising:

• a rotor having an outer circumference carrying magnetic field producing elements, said magnetic field producing elements being arranged so as to produce a magnetic field that alternates in direction around said circumference of the rotor;
• and
• a first stator including:
• a series of stator windings, the series being arranged in a circle which defines a circumference of the first stator, the series of windings having arc sections, each of the arc sections containing windings associated with only one of said at least two phases, the arc sections being arranged such that, when current flows through the windings, each arc section provides a magnetic field which, at any given instant of time during current flow, alternates in direction along a length of each arc section;
• wherein each arc section is associated with a respective one of said at least two phases such that no two arc sections carry current of identical phase;
• wherein the arc sections include an inter-phase separation space between adjacent ones of said arc sections, said inter-phase separation space being different from an intra-phase separation space which separates immediately adjacent windings in a single arc section;
• and
• wherein a width of the inter-phase separation space is greater than a width of the intra-phase separation space;
• and
• an annular stator core, said annular stator core having a radially inner surface, a radially outer circumferential surface, and two sides extending therebetween, said annular stator core further comprising slots which extend between said radially outer circumferential surface and said radially inner surface to define teeth on one of said two sides of the annular stator core, said stator windings being defined by conductive material extending through said slots and around said teeth, said stator windings being defined by serpentine-shaped conductors which fit between and around said teeth, each serpentine-shaped conductor being coextensive with a respective one of the arc segments, each serpentine conductor having a uniformed height;
• wherein portions of said serpentine-shaped conductors which are located outside of said slots have a larger cross sectional area and width in the radial direction than a circumferential width of a portion of one of the serpentine-shaped conductors which are located in the slots;
• wherein each arc section is associated with a respective one of said three phases such that no two arc sections carry current of identical phase;
• wherein said difference between said inter-phase separation space and said intra-phase separation space corresponds to a difference in phase;
• and
• wherein said first stator is axially spaced from said rotor to define an air gap therebetween, said first stator being selectively movable in an axial direction from said rotor to vary said air gap;
• and
• a mechanism for varying said air gap.