Coreless-brushless motor

Claim 2

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor yoke affixed to the rotary shaft; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; a recess formed in the stator yoke on the side of the driving coil block; a magnetoelectric transducer pellet housed in the recess, for detecting the magnetic field of the rotor magnet; and a flexible printed circuit sheet having a wire connected to the magnetoelectric transducer element pellet and interposed between the driving coil block and the stator yoke.

Claim 3

A coreless-brushless motor according to claim 1, wherein electrodes of the magnetoelectric transducer pellet are disposed to face towards the driving coil block.

Claim 4

A coreless-brushless motor according to claim 2, wherein a shallow depression contiguous to the recess is formed in the stator yoke to surround the recess, and wherein the flexible printed circuit sheet is extended onto the bottom of the shallow depression, wires on the extended portion of the flexible printed circuit sheet and the electrodes of the magnetoelectric transducer pellet being interconnected by means of wire bonding.

Claim 5

A coreless-brushless motor according to claim 1, wherein electrodes of the magnetoelectric transducer pellet are opposite to the bottom of the recess.

Claim 6

A coreless-brushless motor according to claim 4, wherein wires are exteded from the flexible printed circuit sheet towards the bottom of the recess and connected to the electrodes of the magnetoelectric transducer pellet.

Claim 7

A coreless-brushless motor according to claim 5, wherein side walls of the recess are tapered outwardly, and wherein the extended wires project out of the flexible printed circuit sheet to extend substantially in parallel to the tapered side walls of the recess.

Claim 8

A coreless-brushless motor according to claim 4, wherein the electrodes of the magnetoelectric transducer pellet are connected to the wires of the flexible printed circuit sheet by means of wire bonding, and wherein the connecting portions and the magnetoelectric transducer pellet are buried in a molding of a resinous material and mounted on the flexible printed circuit sheet, the molding having incorporated therein being housed in the recess.

Claim 9

A coreless-brushless motor according to any one of claims 1 to 7, wherein the magnetoelectric transducer pellet is a Hall element pellet.

Claim 10

A coreless-brushless motor according to any one of claims 1, 2 and 4, wherein the flexible printed circuit sheet has formed thereon a frequency generating coil responsive to magnetic fluxes from the rotor magnet to induce an AC signal of a frequency proportional to the revolving speed of the rotor magnet.

Claim 11

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor yoke affixed to the rotary shaft; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; wherein each of said sheet coils comprises a plurality of interconnect conductor layers formed at predetermined positions on the same insulating sheet as the spiral coils are formed so that when said sheet coils are laminated, the corresponding interconnect conductor layers of the respective sheet coils lie one upon another via the respective insulating sheets to form a plurality of interconnect sections each having a through hole bored through the laminated interconnect conductor layers, the insulating sheets and the insulating layers; one winding end of one of the sheet coils is extended to merge into one of the interconnect conductor layers of said one of the sheet coils, said one of the interconnect conductor layers belonging to one or said interconnect sections; and connecting conductor pins are pressed into respective said through holes so that their outer peripheral surfaces are electrically connected to those portions of the interconnect conductor layers exposed onto the inner peripheral surfaces of the through holes.

Claim 12

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor yoke affixed to the rotary shaft; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; wherein each of said sheet coils comprises a plurality of interconnect conductor layers formed at predetermined positions on the same insulating sheet as the spiral coils are formed so that when said sheet coils are laminated, the corresponding interconnect conductor layers of the respective sheet coils lie one upon another via the respective insulating sheets to form a plurality of interconnect sections each having a through hole bored through the laminated interconnect conductor layers, the insulating sheets and the insulating layers; one winding end of one of the sheet coils is extended to merge into one of the interconnect conductor layers of said one of the sheet coils, said one of the interconnect conductor layers belonging to one or said interconnect sections; and connecting conductor pins are pressed into respective said through holes so that their outer peripheral surfaces are electrically connected to those portions of the interconnect conductor layers exposed onto the inner peripheral surfaces of the through holes.

Claim 13

A coreless-brushless motor according to claim 10, wherein one winding end of one of the other sheet coils is extended to merge into one of the interconnect conductor layers on the same insulating sheet which belongs to said one of the interconnect sections, thereby interconnecting the winding ends of said one of the sheet coils and said one of the other sheet coils through the connecting conductor pin of said one of the interconnect sections.

Claim 14

A coreless-brushless motor according to claim 10, wherein said driving coil block comprises a printed circuit sheet laminated together with said sheet coils; said printed circuit sheet comprises a plurality of interconnect conductor layers formed on one side of an insulating sheet at the positions corresponding to the respective interconnect sections and connected thereto by said connecting conductor pins, respectively, and a wiring conductor pattern formed on the same insulating sheet; one winding end of one of the other sheet coils is extended to merge into one of the interconnect conductor layers which belongs to both one of the other interconnect sections and said one of the other coil sheets; and the wiring conductor pattern includes a wiring connecting both the interconnect conductor layers of said printed circuit sheet belonging to said one of the interconnect sections and said one of the other interconnect sections, respectively, thereby electrically connecting said one winding end of said one of the sheet coils to said one winding end of said one of the other sheet coils.

Claim 15

A coreless-brushless motor according to claim 10, wherein said driving coil block comprises a terminal sheet laminated together with said sheet coils; said terminal sheet comprises a plurality of interconnect conductor layers formed on an insulating sheet at the positions corresponding to the respective interconnect sections and connected thereto by said connecting conductor pins, respectively, and a conductor pattern of terminals and a wiring connecting one of the terminals to one of the interconnect conductor layers of said terminal sheet which belongs to said one of the interconnect sections, thereby electrically leading out said one winding end of said one of the sheet coils as one winding end of said driving coil block through said connecting conductor pin to said one of the terminals.

Claim 16

A coreless-brushless motor according to claim 12, wherein said printed circuit sheet comprises a terminal section radially extending out from the outer circumference of said drive coil block and having formed thereon a plurality of terminals connected to said interconnect conductor layers of said printed circuit sheet.

Claim 17

A coreless-brushless motor according to claim 10, wherein a printed circuit board is laminated together with said sheet coils of the driving coil block; and said printed circuit board comprises: a plurality of interconnect conductor layers formed thereon at the positions corresponding to the respective interconnect sections and connected thereto by said connecting conductor pins extended into through holes bored in said printed circuit board in alignment with the through holes of said interconnect sections; a terminal section radially extending out from the outer circumference of said driving coil block; and a plurality of terminals formed on said terminal section and connected to the interconnect conductor layers of said printed circuit board.

Claim 18

A coreless-brushless motor according to claim 15, wherein the printed circuit board has formed thereon a frequency generating coil responsive to magnetic fluxes from the rotor magnet to induce an AC signal.

Claim 19

A coreless-brushless motor according to any one of claims 10 to 14, wherein each connecting conductor pin has at its both end portions flanges formed integrally with the peripheral surface thereof, by which the laminated structure is resiliently held.

Claim 20

A coreless-brushless motor according to any one of claims 10 to 14, wherein one end of at least one of said connecting conductor pins is extended from the laminated structure to form a pin terminal.

Claim 22

A forming method according to claim 19, wherein in the step of supplying current to the connecting conductor pin, pressure is applied to the connecting conductor pin in a direction to compress it, thereby making it slightly thicker and forming flanges at its both ends.

Claim 23

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor yoke affixed to the rotary shaft; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; a frequency generating coil disposed between the rotor magnet and the stator yoke and responsive to magnetic fluxes from the revolving rotor magnet to induce an AC signal of a frequency proportional to the revolving speed of the rotor magnet; a canceller supplied with the output of the frequency generating coil and a branched portion of a drive current to the driving coil block, for removing from the AC signal a component induced in the frequency generating coil by magnetic fluxes emanating from the driving coil block on the basis of the drive current; and a control circuit supplied with the output of the canceller, for controlling the magnitude of the drive current.

Claim 24

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor yoke affixed to the rotary shaft; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; a frequency generating coil disposed between the rotor magnet and the stator yoke and responsive to magnetic fluxes from the revolving rotor magnet to induce an AC signal of a frequency proportional to the revolving speed of the rotor magnet; a canceller supplied with the output of the frequency generating coil and a branched portion of a drive current to the driving coil block, for removing from the AC signal a component induced in the frequency generating coil by magnetic fluxes emanating from the driving coil block on the basis of the drive current; and a control circuit supplied with the output of the canceller, for controlling the magnitude of the drive current.

Claim 25

A coreless-brushless motor according to claim 21, wherein the frequency generating coil comprises a plurality of pairs of straight frequency generating coil segments; the frequency generating coil segments of each pair are disposed obliquely at the same angle to and symmetrically on both sides of one of radial lines arranged at equiangular intervals about the rotary shaft and connected at one end to each other on said one radial line and connected at the other ends respectively to those of the frequency generating coil segments of the adjoining pairs so that all the frequency generating coil segments are sequentially connected in series; and the series connection of the frequency generating coil segments is cut off at one place for connection to terminals.

Claim 26

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; and a frequency generating coil disposed between the rotor magnet and the stator yoke, the frequency generating coil being formed by a plurality of pairs of straight frequency generating coil segments, the frequency generating coil segments of each pair being disposed obliquely at the same angle to and symmetrically on both sides of one of radial lines arranged at equiangular intervals about the rotary shaft and connected at one end to each other on said one radial line and connected at the other ends respectively to those of the frequency generating coil segments of the adjoining pairs so that all the frequency generating coil segments are sequentially connected in series, and the series connection of the frequency generating coil segments being cut off at one place for connection to terminals.

Claim 27

A coreless-brushless motor comprising: a stator yoke; a driving coil block comprising a plurality of sheet coils, each having a plurality of spiral coils formed by 10 to 200 µm thick conductor patterns arranged on a circle at equiangular intervals on at least one side of an insulating sheet 30 µm or less thick, the plurality of sheet coils being sequentially laminated, with an insulating layer 30 µm or less thick interposed between adjacent ones of them, and fixed to the stator yoke; a bearing fixed to the stator yoke; a rotary shaft rotatably supported by the bearing; a rotor magnet mounted on the rotor yoke in adjacent and opposing relation to the driving coil block; and a frequency generating coil disposed between the rotor magnet and the stator yoke, the frequency generating coil being formed by a plurality of pairs of straight frequency generating coil segments, the frequency generating coil segments of each pair being disposed obliquely at the same angle to and symmetrically on both sides of one of radial lines arranged at equiangular intervals about the rotary shaft and connected at one end to each other on said one radial line and connected at the other ends respectively to those of the frequency generating coil segments of the adjoining pairs so that all the frequency generating coil segments are sequentially connected in series, and the series connection of the frequency generating coil segments being cut off at one place for connection to terminals.

Claim 28

A coreless-brushless motor according to claim 1, wherein the driving coil block has interconnect sections, each comprising interconnect conductor layers formed on the insulating sheets and laminated in opposing relation, with one of the insulating sheets or the insulating layers interposed between adjacent ones of them, and a through hole bored through the interconnect conductor layers, the insulating sheets and the insulating layers, and interconnect conductor pins, each pressed into one of the through holes and having its outer peripheral surface connected through solder to those portions of the interconnect conductor layers exposed onto the inner peripheral surface of the through hole.

Claim 29

A coreless-brushless motor according to claim 24, wherein a frequency generating coil is disposed between the stator yoke and the rotor magnet, the frequency generating coil being formed by a plurality of pairs of straight frequency generating coil segments, the frequency generating coil segments of each pair being disposed obliquely at the same angle to one of radial lines arranged at equiangular intervals about the rotary shaft and connected at one end to each other on said one radial line and connected at the other ends respectively to those of the frequency generating coil segments of the adjoining pairs so that all the frequency generating coil segments are sequentially connected in series, and the series connection of the frequency generating coil segments being cut off at one place for connection to terminals.

Claim 30

A coreless-brushless motor according to claim 10, wherein a frequency generating coil is disposed between the stator yoke and the rotor magnet, the frequency generating coil being formed by a plurality of pairs of straight frequency generating coil segments, the frequency generating coil segments of each pair being disposed obliquely at the same angle to and symmetrically on both sides of one of radial lines arranged at equiangular intervals about the rotary shaft and connected at one end to each other on said one radial line and connected at the other ends respectively to those of the frequency generating coil segments of the adjoining pairs so that all the frequency generating coil segments are sequentially connected in series, and the series connection of the frequency generating coil segments being cut off at one place for connection to terminals.

Claim 31

A coreless-brushless motor according to claim 12, 13, 14 or 24, wherein the interconnect conductor layers on each insulating sheet are arranged inside the circular arrangement of the spiral coils.

Claim 32

A coreless-brushless motor according to claim 12, wherein the other side of the printed circuit sheet has formed thereon a frequency generating coil responsive to magnetic fluxes from the rotor magnet to induce an AC signal of a frequency proportional to the revolving speed of the rotor magnet.

Claim 33

A coreless-brushless motor according to claim 28, wherein the interconnect conductor layers on each insulating sheet are arranged inside the circular arrangement of the spiral coils.

Claim 34

A coreless-brushless motor according to claim 29, wherein the printed circuit sheet has a terminal section extending outwardly of the arrangement of coils of the laminated sheet coils, terminals of the interconnected sheet coils and the terminals of the frequency generating coil are led out through the wire patterns onto the terminal section.