Permanent magnet direct current (PMDC) machine with integral reconfigurable winding control

The method of providing a permanent magnet direct current motor, comprising:

• providing said motor with a stator, including a magnetic core, and a rotor, wherein said rotor and stator have an air gap between them,
• providing poles in the form of permanent magnets on said rotor for producing a field across said air gap,
• providing said core with more slot paths than there are poles on said rotor,
• providing each slot path with at least one coil in each slot of the slot path and passing direct current through said coils,
• positioning the coils of each slot path so that they receive flux from said poles which reverses direction each time a different pole passes flux through the coils of the slot path, and
• reversing the direction of current flow through a coil whenever the flux through that coil reverses itself.

A motor, comprising:

• a stator,
• a rotor having a plurality of poles and an axis of rotation,
• said rotor and stator defining an air gap between them,
• said rotor having magnet means for providing a magnetic field through the air gap,
• first and second groups of coils on said stator each group having a coil at each of a number of positions on said stator with said positions being equally angularly spaced about said axis, each said group being angularly spaced about said axis from each other group, the number of said positions in each group being equal to the number of poles on the rotor,
• switching means for connecting said coils in first and second different configurations, the second of which will produce greater speed with substantially the same torque as the first, and
• control means responsive to a predetermined operating condition of said motor while the coils are in said second configuration for controlling said switching means to connect the coils in said first configuration.

A permanent magnet machine comprising:

• a stator element,
• a rotor element,
• said elements defining an air gap between them,
• a number of poles, fed by at least one permanent magnet on said rotor element for providing magnetic flux across said air gap,
• said stator element having a plurality of slot paths,
• each slot path having at least as many slots as there are poles on the machine,
• each slot path having a circuit with at least two coils in each slot of the slot path, and
• at least one switch for reconfiguring at least some of the coils in at least one slot path to provide different modes of operation of the machine.

A direct current machine, comprising:

• said machine having a rotor with poles and including means for providing said poles with magnetic flux,
• said rotor being rotatable about an axis of rotation,
• said machine having a stator,
• said rotor and stator defining an air gap between them,
• said stator having at least several slot paths,
• each said slot path having at least as many coils on said stator as there are poles on said rotor and also having coils equally angularly spaced around said axis of rotation,
• first and second conductors,
• each slot path having:
• (a) its coils electrically connected together so that there is a path for current to flow from one end of one of said coils of the slot path to one end of another of said coils of the slot path,
• (b) a first connection from said first conductor to said one end of said one coil,
• (c) a second connection from said second conductor to said one end of said another coil, and
• (d) means for reversing said connections so that said first conductor is connected to said one end of said another coil and said second conductor is connected to said one end of said one coil.

A d.c. machine, comprising:

• a rotor having poles and also having an axis rotation,
• said rotor also having at least one magnet for providing said poles with flux,
• a stator extending around said rotor,
• at least two sets of coils mounted on said stator,
• each said set comprising a number of coils mounted on said stator equal in number to the number of poles on said rotor, with the coils of each set equally angularly spaced around said axis of rotation,
• each said set being angularly spaced about said axis from all other such sets, and
• a power line having first and second conductors,
• each said set having first and second connections between the coils of the set and said power line for the transfer of power between the coils and the power line,
• each set including means for reversing its said connections thereby causing the coils of the set to apply a substantially continuous torque to said rotor.

A permanent magnet d.c. machine, comprising:

• a rotor having poles and also having an axis of rotation,
• at least one permanent magnet for providing said poles with flux,
• a stator extending around said rotor,
• at least two sets of coils mounted on said stator,
• each said set comprising at least one coil in each of a number of positions wherein said number of positions is equal to the number of poles on said rotor and with the positions of each set equally angularly spaced around said axis of rotation,
• each said set being angularly spaced about said axis from all other such sets, and
• a power line having first and second conductors,
• each said set having first and second connections from said power line to the coils of the set, and also having additional connections between the coils,
• the said additional connections enabling the machine to operate in one mode when the coils are interconnected in one way and to operate in another mode when the coils are interconnected in another way, and
• solid state switches controlled by the rotation of said rotor for (1) reversing the direction of current flow through the coils of a set, and (2) switching from said first-named mode to the second-named mode by changing from said one way of interconnecting the coils to said second way of interconnecting the coils.