US3757147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepping motor
Assignee: Cambridge Thermionic Corp
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Filing: 1971-05-18
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Granted: 1973-09-04
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Expires: 1991-05-18
Abstract
Abstract A multiphase rotary stepping motor of the type having a shaft with the rotors distributed axially thereon, and a housing carrying the axially distributed stators, the rotors and stators having their respective pole-forming elements separated by axial air gaps. The shaft is mounted for rotation in the housing by a bearing arrangement which includes an axially fixed bearing, such as a duplex bearing, located at one end of the motor to restrict axial motion of the shaft, and an axially floating bearing located at the other end of the motor and freely allowing the shaft to move axially as a result of thermal expansion and contraction. Mounted on the free end of the shaft are inertial damping means in the form of an annular mass concentric with the shaft, with a spring and disks of low friction material, such as Teflon, linking the shaft and annular mass in a predetermined pressure and friction relationship.
Inventors
- 👤 F Lyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:18
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/22; H02K37/02; H02K37/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
206 words
A multiphase rotary stepping motor comprising a shaft; a plurality of motor phases distributed axially along said shaft, each of said phases comprising a rotor portion rotationally and axially secured to said shaft and having radially extending pole pieces, and a stator portion around said rotor portion and having a coil and pole pieces, said stator pole pieces being alignable with and separated by gaps from their associated rotor pole pieces for developing a flux path therethrough upon passage of current in said coil; housing means secured to said stator portions; and bearing means associated with said housing means for mounting said shaft, said bearing means comprising an axially fixed bearing located at one end of said motor phases for axially positioning said stator and rotor pole pieces with respect to each other and for restricting axial motion of said shaft at said one end, said axially fixed bearing being a duplex bearing having separate single bearings in face to face relationship; an axially floating bearing located at the other end of said motor phases and permitting axIal motion of said shaft and said rotor pole pieces over a preselected distance, said gaps accommodating the axial motion of said rotor pole pieces over said preselected distance.
Claim 2
Dependent Claim
206 words
A multiphase rotary stepping motor comprising a shaft; a plurality of motor phases distributed axially along said shaft, each of said phases comprising a rotor portion rotationally and axially secured to said shaft and having radially extending pole pieces, and a stator portion around said rotor portion and having a coil and pole pieces, said stator pole pieces being alignable with and separated by gaps from their associated rotor pole pieces for developing a flux path therethrough upon passage of current in said coil; housing means secured to said stator portions; and bearing means associated with said housing means for mounting said shaft, said bearing means comprising an axially fixed bearing located at one end of said motor phases for axially positioning said stator and rotor pole pieces with respect to each other and for restricting axial motion of said shaft at said one end, said axially fixed bearing being a duplex bearing having separate single bearings in face to face relationship; an axially floating bearing located at the other end of said motor phases and permitting axIal motion of said shaft and said rotor pole pieces over a preselected distance, said gaps accommodating the axial motion of said rotor pole pieces over said preselected distance.
Claim 3
Dependent Claim
98 words
A multiphase rotary stepping motor comprising a shaft; a plurality of phases each comprising a rotor portion secured to said shaft and having rotor pole pieces, and a stator portion around said rotor portion and having stator pole pieces alignable with said rotor pole pieces; and damping means mounted on said shaft for absorbing energy imparted to said shaft and causing substantial acceleration thereof, said damping means including a flange rotating said shaft; a floating annular mass rotatable around said shaft; and means frictionally interengaging said flange and mass and permitting slippage therebetween upon acceleration of said shaft.
Claim 4
Dependent Claim
98 words
A multiphase rotary stepping motor comprising a shaft; a plurality of phases each comprising a rotor portion secured to said shaft and having rotor pole pieces, and a stator portion around said rotor portion and having stator pole pieces alignable with said rotor pole pieces; and damping means mounted on said shaft for absorbing energy imparted to said shaft and causing substantial acceleration thereof, said damping means including a flange rotating said shaft; a floating annular mass rotatable around said shaft; and means frictionally interengaging said flange and mass and permitting slippage therebetween upon acceleration of said shaft.
Claim 5
Dependent Claim
65 words
A multiphase rotary stepping motor according to claim 2 wherein said damping means comprises a sleeve carrying said flange and mounted on said shaft, said annular mass comprising a pair of members on opposite sides of said sleeve flange and being resiliently urged together, said frictionally interengaging means comprising a pair of friction reducing disks disposed in contact with the sides of said sleeve flange.
Claim 6
Dependent Claim
45 words
A multiphase rotary stepping motor according to claim 3 wherein the annular mass members resiliently urged against said sleeve flange comprise a flange on said annular mass, and a washer disposed within said annular mass and being resiliently urged toward said flanges by a spring.
Claim 7
Dependent Claim
153 words
A multiphase rotary stepping motor comprising a shaft; a plurality of phases each comprising a rotor portion secured to said shaft and having rotor pole pieces, and a stator portion around said rotor portion and having stator pole pieces alignable with said rotor pole pieces; and damping means mounted on said shaft for absorbing energy imparted to said shaft and causing substantial acceleration thereof, said damping means comprising a sleeve secured to said shaft; a radially extending flange integral with said sleeve; an annular mass having a first portion with a flange extending radially inward and adjacent to said sleeve flange, and a second portion secured to said first portion, an axial compression spring disposed between said first and second portions, and a washer between said sleeve flange and said spring; and disks of friction reducing material between said sleeve flange and said mass flange and between said sleeve flange and said washer.
Claim 8
Dependent Claim
153 words
A multiphase rotary stepping motor comprising a shaft; a plurality of phases each comprising a rotor portion secured to said shaft and having rotor pole pieces, and a stator portion around said rotor portion and having stator pole pieces alignable with said rotor pole pieces; and damping means mounted on said shaft for absorbing energy imparted to said shaft and causing substantial acceleration thereof, said damping means comprising a sleeve secured to said shaft; a radially extending flange integral with said sleeve; an annular mass having a first portion with a flange extending radially inward and adjacent to said sleeve flange, and a second portion secured to said first portion, an axial compression spring disposed between said first and second portions, and a washer between said sleeve flange and said spring; and disks of friction reducing material between said sleeve flange and said mass flange and between said sleeve flange and said washer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |