Magnetically commutated brushless d.c. torque motor

Claim 2

In a direct current motor that includes permanent magnet motor field means rotatable about a central axis and a stationary armature winding means for producing rotary movement about said common central axis in response to a changing polarity current in said armature winding means, said armature winding means having a plurality of winding groups distributed about said axis; a first circular array of angularly-aligned, normally-open, magnetic reed switches spaced about said axis and fixed relative to said armature winding means, said first array connected to a first terminal and each of said switches in said first array individually connected to one end of each of said winding groups through a corresponding spring in contact with a corresponding commutator bar attached to the armature winding means; a second circular array of angularly-aligned, normally-open, magnetic reed switches spaced about said axis so that each switch in said second array is opposite and aparT from a corresponding switch in said first array and fixed relative to said armature winding means, said second array, connected to a second terminal and each of said switches in said second array individually connected to the other end of each of said winding groups through a spring shared with a switch in said first array connected to a subsequent winding group and the corresponding commutator bar, each of said commutator bars is in electrical contact with the ends of two armature winding groups; and a permanent magnet actuating means comprising a plate rotatable in unison with said permanent magnet motor field and carrying spaced magnets for simultaneously closing the reed switches connected to opposite ends of a selected winding group and sequentially actuating each of said winding groups said first array consisting of 33 reed switches and said second array consisting of 33 reed switches.

Claim 3

Apparatus as in claim 1 wherein the said plate of the permanent magnet actuating means contains two magnet locations on a first side of the plate with shielding means on the second side of the plate in back of each of the magnet locations and two magnet locations on a second side of the plate at different angular positions from the magnets on the first side with shielding means on the first side in back of each of these second magnet locations.

Claim 4

In a direct current motor that includes permanent magnet motor field means and armature winding means for producing relative rotary movement about a common central axis in response to a current in said armature winding means, said armature winding means having a number of winding groups distributed about said axis; a first circular array comprising a corresponding number of equi-angularly spaced, radially extending, normally-open magnetic switches spaced about said axis, separate means connecting such of said switches of said first array to one end of a corresponding one of said winding groups; a common first terminal connected to each of said switches, a second circular array comprising a corresponding number of equi-angularly spaced, radially extending, normally-open magnetic reed switches spaced about said axis, separate means connecting each of said switches of said second array to the opposite end of a corresponding one of said winding groups; a common second terminal connected to each of said switches of said second array; and rotatable means mounting a plurality of first magnetic actuating means for controlling operation of the switches of said first array and a plurality of second magnetic actuating means for cooperatively controlling operation of the switches of said second array for simultaneously closing the ones of said switches connected to opposite ends of the same winding group, said plurality of first actuating means being spaced in a predetermined angular relation about said axis to define an open angular region of sufficient extent to span several of said switches of said first array and said plurality of second actuating means being spaced in a corresponding predetermined angular relation about said axis to define an open angular region of sufficient extent to span several of said switches of said second array, each of said first and second actuating means being of sufficient angular span to maintain actuation of a closed switch until after the next succeeding switch of its corresponding array is closed to provide a continuously acting force field of narrower spread and in more direct angular alignment with the permanent magnet motor field means so as to impart higher continuous torque.

Claim 5

In a direct current motor that includes permanent magnet motor field means and armature winding means for producing relative rotary movement about a common central axis in response to a current in said armature winding means, said armature winding means having a number of winding groups distributed about said axis; a first circular array comprising a corresponding number of equi-angularly spaced, radially extending, normally-open magnetic switches spaced about said axis, separate means connecting such of said switches of said first array to one end of a corresponding one of said winding groups; a common first terminal connected to each of said switches, a second circular array comprising a corresponding number of equi-angularly spaced, radially extending, normally-open magnetic reed switches spaced about said axis, separate means connecting each of said switches of said second array to the opposite end of a corresponding one of said winding groups; a common second terminal connected to each of said switches of said second array; and rotatable means mounting a plurality of first magnetic actuating means for controlling operation of the switches of said first array and a plurality of second magnetic actuating means for cooperatively controlling operation of the switches of said second array for simultaneously closing the ones of said switches connected to opposite ends of the same winding group, said plurality of first actuating means being spaced in a predetermined angular relation about said axis to define an open angular region of sufficient extent to span several of said switches of said first array and said plurality of second actuating means being spaced in a corresponding predetermined angular relation about said axis to define an open angular region of sufficient extent to span several of said switches of said second array, each of said first and second actuating means being of sufficient angular span to maintain actuation of a closed switch until after the next succeeding switch of its corresponding array is closed to provide a continuously acting force field of narrower spread and in more direct angular alignment with the permanent magnet motor field means so as to impart higher continuous torque.

Claim 6

Apparatus as in claim 3 wherein said rotatable means is a plate positioned between said first and second arrays and movable relative to said arrays, said plate contains first permanent magnet means facing the first array and constituting said first actuating means and second permanent magnet means facing the second array and constituting said second actuating means.

Claim 7

Apparatus as in claim 4 wherein said first magnet means consists of two permanent magnet locations and said second magnet means consists of two permanent magnet locations at different but corresponding angular positions from the locations of the first magnet means.

Claim 8

Apparatus as in claim 5 wherein a magnetic field shielding means is located on the opposite side of the plate in back of each magnet location.