US3579276A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Harmonic drive for digital step motor
Assignee: MESURMATIC ELECTRONICS CORP
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Filing: 1967-03-31
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Granted: 1971-05-18
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Expires: 1987-03-31
Abstract
Abstract A step motor has first and second circular coaxial gears mounted on a rotor disc for pivoting and rotation relative to a shaft extending through the disc. Third and fourth circular coaxial gears are arranged to mesh with respective ones of the first and second gears but are normally separated along the shaft from the first and second gears so that meshing can occur only in a limited common sector of the gears upon tilting of the disc on the shaft. The third gear is fastened irrotationally relative to the axis and the fourth gear is fastened to the shaft. The disc comprises electromagnetic material and is subjected to an electromagnetic field that rotates about the shaft, in response to sequential energization of electromagnetic actuators disposed in a circular array about the shaft, to produce wobble motion of the disc about the shaft. At least one pair of meshing gears have different numbers of teeth so that wobble of the disc is accompanied by rotation of the fourth gear, and hence, of the shaft, about the axis.
Inventors
- 👤 Harold R Newell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:34
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/06; H02K41/065; F; F16; F16H; F16H49/00; F16H49/001; F16H1/00; F16H1/28; F16H1/32; F16H1/321
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
217 words
A step motor, comprising first and second circular coaxial gears mounted for common rotation about their axis, third and fourth circular coaxial gears sharing said axis and cooperating with said first and second gears to undergo respective meshing therewith, coupling means normally separating said first and second gears axially from said third and fourth gears and providing a pivot for tilting of said first and second gears relative to said axis into meshing engagement with a common sector of said third and fourth gears, means securing said third gear in irrotational relation to said axis, a shaft extending only along said axis, and projecting through said coupling means to permit rotation of said first and second gears relative to said shaft while undergoing tilting relative to said axis, means fastening said fourth gear to said shaft for rotation therewith, and means effective, when actuated, to exert a circularly moving deflecting force on said first and second gears to produce circularly moving tilting thereof in a wobble motion about said shaft to enable said meshing engagement, said first and third meshing gears having different numbers of teeth thereon so that wobbling of said first and second gears about said shaft is accompanied by rotation of said fourth gear, and with it, rotation of said shaft about said axis.
Claim 2
Dependent Claim
217 words
A step motor, comprising first and second circular coaxial gears mounted for common rotation about their axis, third and fourth circular coaxial gears sharing said axis and cooperating with said first and second gears to undergo respective meshing therewith, coupling means normally separating said first and second gears axially from said third and fourth gears and providing a pivot for tilting of said first and second gears relative to said axis into meshing engagement with a common sector of said third and fourth gears, means securing said third gear in irrotational relation to said axis, a shaft extending only along said axis, and projecting through said coupling means to permit rotation of said first and second gears relative to said shaft while undergoing tilting relative to said axis, means fastening said fourth gear to said shaft for rotation therewith, and means effective, when actuated, to exert a circularly moving deflecting force on said first and second gears to produce circularly moving tilting thereof in a wobble motion about said shaft to enable said meshing engagement, said first and third meshing gears having different numbers of teeth thereon so that wobbling of said first and second gears about said shaft is accompanied by rotation of said fourth gear, and with it, rotation of said shaft about said axis.
Claim 3
Dependent Claim
76 words
The step motor according to claim 1 further including a magnetically permeable disc on which said first and second gears are mounted for said common rotation, and wherein said actuating means includes a plurality of electromagnetic actuators disposed in a circular array about said axis and responsive to sequential energization in a predetermined switching format to produce an electromagnetic field in the vicinity of said disc for exerting said circularly moving deflecting force on said disc.
Claim 4
Dependent Claim
18 words
The Step motor according to claim 2 wherein said disc is at least partly composed of flexible material.
Claim 5
Dependent Claim
55 words
the motor of claim 1 wherein said coupling means includes a disc on which said first and second gears are mounted for said common rotation, said disc having an axial opening, and a universal bearing retained on said shaft and received within said disc opening for pivotally and rotationally coupling said disc to said shaft.
Claim 6
Dependent Claim
31 words
The step motor according to claim 4 wherein said disc is substantially limited to a tilt angle on the order of one degree relative to a plane perpendicular to said shaft.
Claim 7
Dependent Claim
203 words
A step motor, including a rigid nutatable circular disc, first and second circular gears secured rigidly and removably to said rigid nutating disc and nutatable therewith, said circular gears both concentric with the axis of said disc, third and fourth nonrotating gears located concentrically of said axis, said fourth of said nonrotating gears being stationary, said nonrotating gears being so located with respect to said circular gears that on nutation of said rigid nutating disc said first gear fully engages said third gear and simultaneously said second gear fully engages said fourth gear at progressively moving points about the circumferences of said disc, said second and fourth gears having different numbers of gear teeth, a rotatable output shaft for said step motor, said output shaft having a longitudinal axis coincident with said axis of said disc, means including a ball and socket joint for mounting said disc on said shaft for nutation about said shaft, the socket of said ball and socket joint being rigidly secured to said disc and said ball of said ball and socket joint being mounted on said shaft, means securing said third gear rigidly and nonrotatably to said shaft, and electromagnetic means for enforcing nutation of said disc.
Claim 8
Dependent Claim
203 words
A step motor, including a rigid nutatable circular disc, first and second circular gears secured rigidly and removably to said rigid nutating disc and nutatable therewith, said circular gears both concentric with the axis of said disc, third and fourth nonrotating gears located concentrically of said axis, said fourth of said nonrotating gears being stationary, said nonrotating gears being so located with respect to said circular gears that on nutation of said rigid nutating disc said first gear fully engages said third gear and simultaneously said second gear fully engages said fourth gear at progressively moving points about the circumferences of said disc, said second and fourth gears having different numbers of gear teeth, a rotatable output shaft for said step motor, said output shaft having a longitudinal axis coincident with said axis of said disc, means including a ball and socket joint for mounting said disc on said shaft for nutation about said shaft, the socket of said ball and socket joint being rigidly secured to said disc and said ball of said ball and socket joint being mounted on said shaft, means securing said third gear rigidly and nonrotatably to said shaft, and electromagnetic means for enforcing nutation of said disc.
Claim 9
Dependent Claim
144 words
A step motor, comprising first and second rotatable gears, means for identically nutating said gears, a stationary gear meshing at first points sequentially taken around its circumference with said first nutatable gear, said first nutatable gear and said stationary gear having different numbers of teeth, an output shaft, a rotatable output gear rigidly coupled to said output shaft to effect rotation of said output shaft, said rotatable output gear meshing at second sequentially taken points around its circumference with said second nutatable gear, said sequential points being always in a common radial plane with respect to the axis of said output shaft, and means securing said nutating gears rotatably on and with respect to said shaft, said last means being a ball and socket joint, of which the socket is rigidly secured to said nutatable gears and said ball is mounted on said shaft.
Claim 10
Dependent Claim
144 words
A step motor, comprising first and second rotatable gears, means for identically nutating said gears, a stationary gear meshing at first points sequentially taken around its circumference with said first nutatable gear, said first nutatable gear and said stationary gear having different numbers of teeth, an output shaft, a rotatable output gear rigidly coupled to said output shaft to effect rotation of said output shaft, said rotatable output gear meshing at second sequentially taken points around its circumference with said second nutatable gear, said sequential points being always in a common radial plane with respect to the axis of said output shaft, and means securing said nutating gears rotatably on and with respect to said shaft, said last means being a ball and socket joint, of which the socket is rigidly secured to said nutatable gears and said ball is mounted on said shaft.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |