US4125792A — Brushless D-C motor

Claim 1

Independent Claim 203 words

A slow speed brushless speed controlled d-c motor having a coreless stator winding and a rotary multipolar permanent magnet rotor which in operation interacts with a rotary field produced by the coreless stator winding, and a sensor arrangement controlled by the rotary position of the rotor connected to control current flow through the stator winding; wherein the stator winding has a maximum of two magnetically active coil sections per pole of the multipolar rotor two coil sections forming a set; the coil sections are located in two superposed layers; and a number of coil sections (62) corresponding to the number of pairs of poles are interconnected and symmetrically distributed in one layer and the same number of coil sections (63) are symmetrically distributed in the second layer of the two layer winding, the coil sections of the second layer being displaced by an angle (α) relative to the coils of the first layer; wherein the displacement angle (α) is an odd multiple of 90°-el and the maximum width of the coils is about 360°-el; means deriving a control signal representative of speed of rotation of the rotor; and means controlling current flow through said stator coil sections in dependence on said control signal.

Claim 2

Dependent Claim 203 words

A slow speed brushless speed controlled d-c motor having a coreless stator winding and a rotary multipolar permanent magnet rotor which in operation interacts with a rotary field produced by the coreless stator winding, and a sensor arrangement controlled by the rotary position of the rotor connected to control current flow through the stator winding; wherein the stator winding has a maximum of two magnetically active coil sections per pole of the multipolar rotor two coil sections forming a set; the coil sections are located in two superposed layers; and a number of coil sections (62) corresponding to the number of pairs of poles are interconnected and symmetrically distributed in one layer and the same number of coil sections (63) are symmetrically distributed in the second layer of the two layer winding, the coil sections of the second layer being displaced by an angle (α) relative to the coils of the first layer; wherein the displacement angle (α) is an odd multiple of 90°-el and the maximum width of the coils is about 360°-el; means deriving a control signal representative of speed of rotation of the rotor; and means controlling current flow through said stator coil sections in dependence on said control signal.

Claim 3

Dependent Claim 13 words

Motor according to claim 1, wherein the displacement angle (α) is 90° electrical.

Claim 4

Dependent Claim 16 words

Motor according to claim 2, wherein the coil sections in one plane are connected in series.

Claim 5

Dependent Claim 24 words

Motor according to claim 2, wherein the coil sections in one plane are wound in bifilar manner (62', 62") and are connected in series.

Claim 6

Dependent Claim 32 words

Motor according to claim 2, wherein the coil sections in one plane are unidirectionally connected in series so that, when current flows through them, they produce magnetic fields having the same direction.

Claim 7

Dependent Claim 25 words

Motor according to claim 1, wherein the motor is an axial airgap motor; and the coil sections are constructed as flat circular coils (62, 63).

Claim 8

Dependent Claim 23 words

Motor according to claim 1, wherein the motor is an eight-pole motor; and two diametrically opposite interconnected coil sections form an interconnected set.

Claim 9

Dependent Claim 41 words

Motor according to claim 7, wherein the coil sections are located on the motor such that imaginary lines passing through the diametrically opposite coil sections of the sets form an angle with each other of 90°-el. or an odd multiple thereof.

Claim 10

Dependent Claim 66 words

Motor according to claim 7, wherein the coil sections are located on the motor such that imaginary lines passing through the diametrically opposite coils of the pairs of coils form an angle of 450°-el. and 270°-el. respectively and wherein the sensor arrangement (68, 69, 107) for determining the rotary position of the rotor (44) is located between the coils including the larger angular range of 450°-el.

Claim 11

Dependent Claim 43 words

Motor according to claim 1, wherein the coil sections form a single winding; and the means controlling current flow through said coil sections control the current to flow therethrough, alternately, in opposite directions to produce magnetic fields having, sequentially, opposite direction of flux.

Claim 12

Dependent Claim 184 words

A brushless d-c motor having a coreless stator winding and a rotary multipolar permanent magnet rotor which in operation interacts with a rotary field produced by the coreless stator winding, and a sensor arrangement controlled by the rotary position of the rotor connected to control current flow through the stator winding; wherein the stator winding has a maximum of two magnetically active coil sections per pole of the multipolar rotor, for each m coil, a magnetically active m coil section and a magnetically active m + 1 coil section per pole are provided, and the successive coil sections are displaced relative to one another by the same angle; respective m-th and (m+)th magnetically active coil sections are combined to form a single coil; and wherein the coil sections are formed by a single coil (99, 100, 101, 102; 138, 139, 142, 143) per pole, of approximately n times the number of ampere turns of an equivalent set of overlapping individual m coils displaced by 90°-el. to provide said rotary field, said single coils being arranged in non-overlapping manner to obtain a single layer winding.

Claim 13

Dependent Claim 184 words

A brushless d-c motor having a coreless stator winding and a rotary multipolar permanent magnet rotor which in operation interacts with a rotary field produced by the coreless stator winding, and a sensor arrangement controlled by the rotary position of the rotor connected to control current flow through the stator winding; wherein the stator winding has a maximum of two magnetically active coil sections per pole of the multipolar rotor, for each m coil, a magnetically active m coil section and a magnetically active m + 1 coil section per pole are provided, and the successive coil sections are displaced relative to one another by the same angle; respective m-th and (m+)th magnetically active coil sections are combined to form a single coil; and wherein the coil sections are formed by a single coil (99, 100, 101, 102; 138, 139, 142, 143) per pole, of approximately n times the number of ampere turns of an equivalent set of overlapping individual m coils displaced by 90°-el. to provide said rotary field, said single coils being arranged in non-overlapping manner to obtain a single layer winding.

Claim 14

Dependent Claim 26 words

Motor according to claim 11, wherein the motor is an axial air gap motor; and the coil sections are constructed as flat circular coils (62, 63).

Claim 15

Dependent Claim 23 words

Motor according to claim 11, wherein the motor is an eight-pole motor; and two diametrically opposite interconnected coil sections form an interconnected set.

Claim 16

Dependent Claim 19 words

Motor according to claim 11, wherein the permanent magnet rotor has a number of poles integrally divisible by 4.

Claim 17

Dependent Claim 27 words

Motor according to claim 11, wherein the placement of said single coils and their number of ampere turns is symmetrical relative to the motor axis of rotation.

Claim 18

Dependent Claim 22 words

Motor according to claim 15, wherein the motor has a number of poles of at least 8; and wherein n = 2.

Claim 19

Dependent Claim 57 words

Motor according to claim 16, wherein (FIG. 4) the motor is an 8-pole motor, four bifilar coils are provided, two pairs of coils (99, 101; 100, 102) each are unidirectionally connected in series and two coils of each pair of coils are located diametrically opposite each other with respect to the axis of rotation of the motor.

Claim 20

Dependent Claim 65 words

Motor according to claim 17, wherein the coils are located on the motor such that imaginary lines passing through the diametrically opposite coils of the pairs of coils form an angle of 450°-el. and 270°-el. respectively and wherein the sensor arrangement (68, 69, 107) for determining the rotary position of the rotor (44) is located between the coils including the larger angular range of 450°-el.

Claim 21

Dependent Claim 24 words

Motor according to claim 15, wherein (FIG. 14) the motor is a 16-pole motor and wherein n is equal to or less than four.

Claim 22

Dependent Claim 55 words

Motor according to claim 15, wherein (FIG. 14) the motor is a 16-pole motor, four coils (138, 139, 142, 143) are provided, two pairs of coils each are connected in series and two coils of each pair of coils are located diametrically opposite each other with respect to the axis of rotation of the motor.

Claim 23

Dependent Claim 35 words

Motor according to claim 20, wherein the coils are located on the motor such that imaginary lines passing through the diametrically opposite coils of the pairs of coils form an angle of 450°-el. or less.

Claim 24

Dependent Claim 24 words

Motor according to claim 15, wherein (FIG. 16) the motor is a 24-pole motor and wherein n is equal to or less than 5.

Claim 25

Dependent Claim 51 words

Motor according to claim 15, wherein (FIG. 16) the motor is a 24-pole motor, four coils are provided, two pairs of coils each are connected in series, and two coils of each pair of coils are located diametrically opposite each other with respect to the axis of rotation of the motor.

Claim 26

Dependent Claim 35 words

Motor according to claim 20, wherein the coils are located on the motor such that imaginary lines passing through the diametrically opposite coils of the pairs of coils form an angle of about 97.5° mechanical.

Claim 27

Dependent Claim 24 words

Motor according to claim 11, wherein the motor is a flat, axial air gap motor and the coils are shaped as flat, circular coils.

Claim 28

Dependent Claim 38 words

Motor according to claim 11, in combination with a speed control circuit; and transducer means provided supplying an actual speed pulse value signal having a pulse count per rotor rotation which is high relative to the motor speed.

Claim 29

Dependent Claim 53 words

Motor according to claim 11, wherein the motor is a slow speed motor adapted for direct drive of phonograph reproducing apparatus, further including speed control means deriving a control signal representative of speed of rotation of the rotor; and means controlling current flow through said coil sections in dependence on said control signal.

Claim 30

Dependent Claim 36 words

Motor according to claim 11, in combination with a speed control circuit; and transducer means supplying an actual speed pulse signal having a pulse count per rotor rotation which is high relative to the motor speed.

Claim 31

Dependent Claim 14 words

Motor according to claim 11, wherein the motor is an axial air gap motor.

Claim 32

Dependent Claim 43 words

Motor according to claim 11, wherein the coil sections form a single winding; and the means controlling current flow through said coil sections control the current to flow therethrough, alternately, in opposite directions to produce magnetic fields having, sequentially, opposite direction of flux.

Claim 33

Dependent Claim 157 words

Axial air gap motor comprising a permanent magent rotor (54) having alternate zones of magnetization forming magnet poles; a coreless stator winding comprising at least four coils (99-102); transducer means interacting with the magnetic field of the rotor to provide a rotor position signal; and circuit means selectively energizing the coils to provide a rotary field for interaction with the rotor poles, wherein the coils are flat coils in which two coils, each form a pair located opposite each other with respect to the axis of rotation of the rotor; oppositely located coils of one pair are connected in series and unidirectionally wound to provide for current flow therethrough in the same direction; and the coils are distributed non-uniformly circumferentially with respect to said axis of rotation such that imaginary lines passing through the opposite coils of a pair form alternatingly electrical angles with respect to each other which are odd whole number multiples of 90° -el.

Claim 34

Dependent Claim 157 words

Axial air gap motor comprising a permanent magent rotor (54) having alternate zones of magnetization forming magnet poles; a coreless stator winding comprising at least four coils (99-102); transducer means interacting with the magnetic field of the rotor to provide a rotor position signal; and circuit means selectively energizing the coils to provide a rotary field for interaction with the rotor poles, wherein the coils are flat coils in which two coils, each form a pair located opposite each other with respect to the axis of rotation of the rotor; oppositely located coils of one pair are connected in series and unidirectionally wound to provide for current flow therethrough in the same direction; and the coils are distributed non-uniformly circumferentially with respect to said axis of rotation such that imaginary lines passing through the opposite coils of a pair form alternatingly electrical angles with respect to each other which are odd whole number multiples of 90° -el.

Claim 35

Dependent Claim 19 words

Motor according to claim 31, wherein the permanent magnet rotor has a number of poles integrally divisible by 4.

Claim 36

Dependent Claim 28 words

Motor according to claim 31, wherein the motor is an eight-pole motor, four coils are provided and the coils are spaced by angles of 270°-el. and 450°-el., respectively.

Claim 37

Dependent Claim 111 words

Motor according to claim 31, wherein the rotor has a number of poles integrally divisible by eight, at least four coils are provided, arranged in coil pairs and spaced mechanically, approximately circumferentially with respect to the axis of rotation of the rotor to interact with the magnetic field of the permanent magnet rotor as determined by the relationship: ______________________________________ Motor poles Large angle Small angle ______________________________________ 8 112.5° 67.5° 16 123.75° 56.25° 24 97.5° 82.5° ______________________________________ wherein the "large angle" and "small angle" columns respectively relate to the mechanical angles between said imaginary diametrical lines, the circumferentially non-uniform placement of said coils resulting in alternately larger and smaller included angles therebetween.

Claim 38

Dependent Claim 22 words

Motor according to claim 31, wherein the transducer means are arranged on a carrier plate (107) arranged between two adjacent flat coils.

Claim 39

Dependent Claim 15 words

Motor according to claim 31, wherein the coils are constructed as circular coils (62, 63).

Claim 40

Dependent Claim 24 words

Motor according to claim 31, wherein the coils are located diametrically opposite each other with respect to the axis of rotation of the rotor.

Claim 41

Dependent Claim 38 words

Motor according to claim 24, wherein the transducer means and at least part of the energization circuit means are located in the space between the coils spaced circumferentially from each other by the greater one of said angles.

Claim 42

Dependent Claim 33 words

Motor according to claim 33, wherein the sensor arrangement (68, 69, 107) for determining the rotary position of the rotor (44) is located between the coils including the larger angular range of 450°-el.

Claim 43

Dependent Claim 53 words

Motor according to claim 31, wherein the motor is a slow speed motor adapted for direct drive of phonograph reproducing apparatus, further including speed control means deriving a control signal representative of speed of rotation of the rotor; and means controlling current flow through said coil sections in dependence on said control signal.

Claim 44

Dependent Claim 36 words

Motor according to claim 31, in combination with a speed control circuit; and transducer means supplying an actual speed pulse signal having a pulse counter per rotor rotation which is high relative to the motor speed.

Claim 45

Dependent Claim 152 words

Electric motor comprising a permanent magnet rotor (54) having alternate zones of magnetization forming magnet poles; a coreless stator winding comprising at least four thin coils (99-103); transducer means interacting with the magnetic field of the rotor to provide a rotor position signal; and circuit means selectively energizing the coils to provide a rotary field for interaction with the rotor poles, wherein the coils are thin flat coils in which two coils, each, form a pair located opposite each other with respect to the axis of rotation of the rotor and wherein oppositely located coils are connected in series to provide for current flow therethrough in the same direction; and the coils are distributed non-uniformly circumferentially with respect to said axis of rotation such that imaginary lines passing centrally through opposite coils of a pair form alternatingly electrical angles with respect to each other which are odd whole number multiples of 90°-el.

Claim 46

Dependent Claim 152 words

Electric motor comprising a permanent magnet rotor (54) having alternate zones of magnetization forming magnet poles; a coreless stator winding comprising at least four thin coils (99-103); transducer means interacting with the magnetic field of the rotor to provide a rotor position signal; and circuit means selectively energizing the coils to provide a rotary field for interaction with the rotor poles, wherein the coils are thin flat coils in which two coils, each, form a pair located opposite each other with respect to the axis of rotation of the rotor and wherein oppositely located coils are connected in series to provide for current flow therethrough in the same direction; and the coils are distributed non-uniformly circumferentially with respect to said axis of rotation such that imaginary lines passing centrally through opposite coils of a pair form alternatingly electrical angles with respect to each other which are odd whole number multiples of 90°-el.

Claim 47

Dependent Claim 11 words

Motor according to claim 42, wherein the coils are bifilar coils.

Claim 48

Dependent Claim 19 words

Motor according to claim 42, wherein the permanent magnet rotor has a number of poles integrally divisible by 4.

Claim 49

Dependent Claim 28 words

Motor according to claim 42, wherein the motor is an eight-pole motor, four coils are provided and the coils are spaced by angles of 270°-el. and 450°-el., respectively.

Claim 50

Dependent Claim 14 words

Motor according to claim 42, wherein said motor is an axial air gap motor.

Claim 51

Dependent Claim 111 words

Brushless d-c motor having a coreless permanent magnet rotor; and a stator coil arrangement having two sets of coil sections (a, b) forming a single layer winding to generate a rotary field on the rotor, wherein the coil sections of any set being symmetrically placed along the circumference of the rotor, one set being offset with respect to the other by (2k + 1) × 90°-el., wherein k = 0, 1, 2, 3, 4 . . . n; at least two coil sections form a set and these coil sections are serially connected and unidirectionally wound with respect to each other, and spaced along the circumference by whole multiples of 360°-el.

Claim 52

Dependent Claim 111 words

Brushless d-c motor having a coreless permanent magnet rotor; and a stator coil arrangement having two sets of coil sections (a, b) forming a single layer winding to generate a rotary field on the rotor, wherein the coil sections of any set being symmetrically placed along the circumference of the rotor, one set being offset with respect to the other by (2k + 1) × 90°-el., wherein k = 0, 1, 2, 3, 4 . . . n; at least two coil sections form a set and these coil sections are serially connected and unidirectionally wound with respect to each other, and spaced along the circumference by whole multiples of 360°-el.

Claim 53

Dependent Claim 24 words

Motor according to claim 47, wherein the coil sections in one plane are wound in bifilar manner (62', 62") and are connected in series.

Claim 54

Dependent Claim 28 words

Motor according to claim 47, wherein the coil sections form a single winding; and means are provided controlling current flow through said coil sections, alternately, in opposite direction.

Claim 55

Dependent Claim 53 words

Motor according to claim 47, wherein the motor is a slow speed motor adapted for direct drive of phonograph reproducing apparatus, further including speed control means deriving a control signal representative of speed of rotation of the rotor; and means controlling current flow through said coil sections in dependence on said control signal.

Claim 56

Dependent Claim 36 words

Motor according to claim 47, in combination with a speed control circuit; and transducer means supplying an actual speed pulse signal having a pulse count per rotor rotation which is high relative to the motor speed.

Claim 57

Dependent Claim 14 words

Motor according to claim 47 wherein said motor is an axial air gap motor.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1981-11-13	1982-05-15	1982-11-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1985-11-13	1986-05-15	1986-11-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1989-11-13	1990-05-15	1990-11-14	$7700.00	Window Closed / Lapsed

Brushless D-C motor

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