US3716788A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tachometer generator
Assignee: Aisin Corp
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Filing: 1970-12-22
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Granted: 1973-02-13
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Expires: 1990-12-22
Abstract
Abstract A tachometer generator has a toothed stator and a toothed rotor which may be formed in one piece with the revolvable inner race of a bearing supporting a shaft whose revolving speed is to be measured, the toothed stator is fixed to the stationary outer race of the same bearing, in such a manner that the toothed surfaces of the rotor and the stator are opposed to each other with a small airgap therebetween. The bearing outer race also supports magnetic means having a coil disposed in a magnetic path formed by the aforesaid bearing and the rotor and stator of the tachometer generator, so that, as the crests and roots of the stator teeth alternately face the crests and roots of the rotor teeth in revolution, a voltage which varies with the corresponding fluctuations in the amount of magnetic flux along the path is electromagnetically induced in the coil.
Inventors
- 👤 K Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 00:46
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/443; F; F16; F16C; F16C41/00; F16C41/007; G01P3/48; G01P3/481; G01P3/488; F16C19/00; F16C19/02; F16C19/04; F16C19/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
268 words
A tachometer generator to generate a high-frequency signal to represent the rotational speed of a rotating axle, comprising, a stationary housing mounted concentrically of the rotating axle; a bearing assembly of ferromagnetic material including an inner race mounted on said axle for rotation therewith, a stationary outer race fixed to said housing, and a plurality of balls of ferromagnetic material interposed for rolling between said inner and outer races; an annular ferromagnetic rotor member formed on an axial extension of said inner race and toothed at its outer periphery; an annular stator member of ferromagnetic material disposed concentrically around the outer periphery of said rotor member and toothed at its inner periphery, the toothed peripheries of said rotor member and said stator member being opposed to each other with an air gap therebetween, said stator member and outer race being axially spaced to define an annular space; a magnet disposed in said angular space to be in contact with the stator member and the outer race for causing magnetic flux to flow in a magnetic path, said magnetic path being completed via said outer race, said plurality of balls, the inner race, the rotor and stator members and the air gap therebetween; and a winding means having output terminals and disposed to be inductively coupled with the magnetic flux in said magnetic path for generating an alternating current signal whose frequency is proportional to a rotational speed of the rotating axle, the tachometer generator being characterized in that said air gap between the stator member and the rotor member is the only non-ferromagnetic part of said magnetic path.
Claim 2
Dependent Claim
268 words
A tachometer generator to generate a high-frequency signal to represent the rotational speed of a rotating axle, comprising, a stationary housing mounted concentrically of the rotating axle; a bearing assembly of ferromagnetic material including an inner race mounted on said axle for rotation therewith, a stationary outer race fixed to said housing, and a plurality of balls of ferromagnetic material interposed for rolling between said inner and outer races; an annular ferromagnetic rotor member formed on an axial extension of said inner race and toothed at its outer periphery; an annular stator member of ferromagnetic material disposed concentrically around the outer periphery of said rotor member and toothed at its inner periphery, the toothed peripheries of said rotor member and said stator member being opposed to each other with an air gap therebetween, said stator member and outer race being axially spaced to define an annular space; a magnet disposed in said angular space to be in contact with the stator member and the outer race for causing magnetic flux to flow in a magnetic path, said magnetic path being completed via said outer race, said plurality of balls, the inner race, the rotor and stator members and the air gap therebetween; and a winding means having output terminals and disposed to be inductively coupled with the magnetic flux in said magnetic path for generating an alternating current signal whose frequency is proportional to a rotational speed of the rotating axle, the tachometer generator being characterized in that said air gap between the stator member and the rotor member is the only non-ferromagnetic part of said magnetic path.
Claim 3
Dependent Claim
268 words
A tachometer generator to generate a high-frequency signal to represent the rotational speed of a rotating axle, comprising, a stationary housing mounted concentrically of the rotating axle; a bearing assembly of ferromagnetic material including an inner race mounted on said axle for rotation therewith, a stationary outer race fixed to said housing, and a plurality of balls of ferromagnetic material interposed for rolling between said inner and outer races; an annular ferromagnetic rotor member formed on an axial extension of said inner race and toothed at its outer periphery; an annular stator member of ferromagnetic material disposed concentrically around the outer periphery of said rotor member and toothed at its inner periphery, the toothed peripheries of said rotor member and said stator member being opposed to each other with an air gap therebetween, said stator member and outer race being axially spaced to define an annular space; a magnet disposed in said angular space to be in contact with the stator member and the outer race for causing magnetic flux to flow in a magnetic path, said magnetic path being completed via said outer race, said plurality of balls, the inner race, the rotor and stator members and the air gap therebetween; and a winding means having output terminals and disposed to be inductively coupled with the magnetic flux in said magnetic path for generating an alternating current signal whose frequency is proportional to a rotational speed of the rotating axle, the tachometer generator being characterized in that said air gap between the stator member and the rotor member is the only nonferromagnetic part of said magnetic path.
Claim 4
Dependent Claim
268 words
A tachometer generator to generate a high-frequency signal to represent the rotational speed of a rotating axle, comprising, a stationary housing mounted concentrically of the rotating axle; a bearing assembly of ferromagnetic material including an inner race mounted on said axle for rotation therewith, a stationary outer race fixed to said housing, and a plurality of balls of ferromagnetic material interposed for rolling between said inner and outer races; an annular ferromagnetic rotor member formed on an axial extension of said inner race and toothed at its outer periphery; an annular stator member of ferromagnetic material disposed concentrically around the outer periphery of said rotor member and toothed at its inner periphery, the toothed peripheries of said rotor member and said stator member being opposed to each other with an air gap therebetween, said stator member and outer race being axially spaced to define an annular space; a magnet disposed in said angular space to be in contact with the stator member and the outer race for causing magnetic flux to flow in a magnetic path, said magnetic path being completed via said outer race, said plurality of balls, the inner race, the rotor and stator members and the air gap therebetween; and a winding means having output terminals and disposed to be inductively coupled with the magnetic flux in said magnetic path for generating an alternating current signal whose frequency is proportional to a rotational speed of the rotating axle, the tachometer generator being characterized in that said air gap between the stator member and the rotor member is the only nonferromagnetic part of said magnetic path.
Claim 5
Dependent Claim
40 words
A tachometer generator as claimed in claim 1, wherein said axial extension of said inner race is an integral part of the inner race and said toothed rotor is thereby formed integrally with the inner race of the bearing assembly.
Claim 6
Dependent Claim
34 words
A tachometer generator as claimed in claim 1, wherein said axial extension of said inner race comprises a ferromagnetic annular spacer member, having teeth formed in its outer periphery and constituting said rotor member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |