US4616512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Torquemeter
Assignee: S HIMMELSTEIN AND Co
•
Filing: 1984-11-23
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Granted: 1986-10-14
•
Expires: 2004-11-23
Abstract
Abstract A nonintrusive, or noncontact, shaft torquemeter for use in measuring torque transmission through a rotatable shaft. The torquemeter includes an annular torque-sensing coil structure having an annular excitation coil and a pickup coil magnetically coupled to the excitation coil through an improved magnetostrictive coupling structure carried by the shaft. In the illustrated embodiment, the magnetostrictive coupling portion is provided on a tube coaxially fixed at its ends to the shaft. The invention comprehends the provision of structure for preventing a continuous annular conductive path through the coupling portion or tube. Other structure for improving torque measuring accuracy may be provided, including the use of an outer magnetic stator core, and the provision of annular corrugations in the tube for preventing transmission of nontorque forces, such as bending forces, to the coupling portion. In one embodiment, the coupling portion is defined by a portion of the mounting tube, and in another embodiment, the coupling portion is defined by a layer of magnetostrictive material on the tube.
Inventors
- 👤 Sydney Himmelstein
- 👤 Richard S. Tveter
- 👤 James P. Beck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:39
CPC Classifications
G; G01; G01L; G01L3/00; G01L3/02; G01L3/04; G01L3/10; G01L3/101; G01L3/102; G01L3/105; Y; Y10; Y10S; Y10S73/00; Y10S73/02
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
160 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion and having an axial extent substantially greater than the axial extent of said coil structure for preventing as continuous annular conductive path through substantially the entirety of said coupling portion of the tube in all angular portions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion.
Claim 2
Dependent Claim
160 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion and having an axial extent substantially greater than the axial extent of said coil structure for preventing as continuous annular conductive path through substantially the entirety of said coupling portion of the tube in all angular portions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion.
Claim 3
Dependent Claim
27 words
The noncontact shaft torquemeter of claim 1 wherein said means associated with said coupling portion of the tube comprises a gap extending radially through said coupling portion.
Claim 4
Dependent Claim
31 words
The noncontact shaft torquemeter of claim 1 wherein said means associated with said coupling portion of the tube comprises a plurality of angularly spaced gaps extending radially through said coupling portion.
Claim 5
Dependent Claim
31 words
The noncontact shaft torquemeter of claim 1 wherein said means associated with said coupling portion of the tube comprises a plurality of equiangularly spaced gaps extending radially through said coupling portion.
Claim 6
Dependent Claim
28 words
The noncontact shaft torquemeter of claim 1 wherein said means associated with said coupling portion of the tube comprises a gap extending fully radially through said coupling portion.
Claim 7
Dependent Claim
16 words
The noncontact shaft torquemeter of claim 1 wherein the entire tube is formed of magnetostrictive material.
Claim 8
Dependent Claim
23 words
The noncontact shaft torquemeter of claim 1 wherein said magnetostrictive coupling portion comprises a thin body of magnetostrictive material coaxially on said tube.
Claim 9
Dependent Claim
172 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube in all angular positions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said tube defining an annular portion having reduced radial thickness and said means associated with said coupling portion of the tube comprising an axial gap through said reduced thickness annular portion.
Claim 10
Dependent Claim
172 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube in all angular positions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said tube defining an annular portion having reduced radial thickness and said means associated with said coupling portion of the tube comprising an axial gap through said reduced thickness annular portion.
Claim 11
Dependent Claim
26 words
The noncontact shaft torquemeter of claim 8 wherein said axial gap further extends through a portion of the tube adjacent to said reduced thickness annular portion.
Claim 12
Dependent Claim
155 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube in all angular positions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said tube including means for peventing transmission of nontorque forces to said coupling portion.
Claim 13
Dependent Claim
155 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube in all angular positions of the shaft without introducing a torque reading discontinuity; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said tube including means for peventing transmission of nontorque forces to said coupling portion.
Claim 14
Dependent Claim
190 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: an annular electrically conductive means arranged to be coaxially of the shaft and having axially spaced portions and defining a magnetostrictive coupling portion therebetween; means for mounting said spaced portions fixedly to the shaft; means associated with said coupling portion and having an axial extent substantially greater than the axial extent of said coil structure for preventing a continuous annular conductive path through said coupling portion in all angular positions of the shaft without introducing a torque reading discontinuity comprising a gap extending radially through and axially the length of said annular electrically conductive means; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion.
Claim 15
Dependent Claim
190 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: an annular electrically conductive means arranged to be coaxially of the shaft and having axially spaced portions and defining a magnetostrictive coupling portion therebetween; means for mounting said spaced portions fixedly to the shaft; means associated with said coupling portion and having an axial extent substantially greater than the axial extent of said coil structure for preventing a continuous annular conductive path through said coupling portion in all angular positions of the shaft without introducing a torque reading discontinuity comprising a gap extending radially through and axially the length of said annular electrically conductive means; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion.
Claim 16
Dependent Claim
30 words
The noncontact shaft torquemeter of claim 1l wherein said magnetostrictive coupling portion has a radial thickness different from the radial thickness of the annular electrically conductive means axially outwardly thereof.
Claim 17
Dependent Claim
30 words
The noncontact shaft torquemeter of claim 11 wherein said magnetostrictive coupling portion has a radial thickness greater than the radial thickness of the annular electrically conductive means axially outwardly thereof.
Claim 18
Dependent Claim
30 words
The noncontact shaft torquemeter of claim 11 wherein said magnetostrictive coupling portion has a radial thickness less than the radial thickness of the annular electrically conductive means axially outwardly thereof.
Claim 19
Dependent Claim
22 words
The noncontact shaft torquemeter of claim 11 wherein said axially spaced portions comprise opposite end portions of the annular electrically conductive means.
Claim 20
Dependent Claim
163 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said magnetostrictive coupling portion having a radial thickness different from the radial thickness of the tube axially thereof and is provided with a gap extending radially through and axially the length of said coupling portion.
Claim 21
Dependent Claim
163 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed to the shaft and defining a magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube; and means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion, said magnetostrictive coupling portion having a radial thickness different from the radial thickness of the tube axially thereof and is provided with a gap extending radially through and axially the length of said coupling portion.
Claim 22
Dependent Claim
17 words
The noncontact shaft torquemeter of claim 16 wherein said gap extends axially the length of said tube.
Claim 23
Dependent Claim
171 words
A noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, comprising: an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil wound transversely about the excitation coil coaxially of the annular axis of the excitation coil to be in space quadrature therewith so as to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween; an annular magnetostrictive wall element; means for carrying the axially opposite ends of said wall element coaxially to the shaft; means for mounting said coil structure coaxially about said wall element at a preselected portion thereof to include said portion in the magnetic coupling path between said coils, said excitation coil providing a magnetic field in said wall element; and means for causing saturation of the magnetic field in said wall element comprising a split core structure extending about said coil structure to adjacent said wall element.
Claim 24
Dependent Claim
171 words
A noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, comprising: an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil wound transversely about the excitation coil coaxially of the annular axis of the excitation coil to be in space quadrature therewith so as to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween; an annular magnetostrictive wall element; means for carrying the axially opposite ends of said wall element coaxially to the shaft; means for mounting said coil structure coaxially about said wall element at a preselected portion thereof to include said portion in the magnetic coupling path between said coils, said excitation coil providing a magnetic field in said wall element; and means for causing saturation of the magnetic field in said wall element comprising a split core structure extending about said coil structure to adjacent said wall element.
Claim 25
Dependent Claim
25 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a tin body of magnetostrictive material on a carrier supported on said shaft.
Claim 26
Dependent Claim
26 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a thin body of magnetostrictive material on a nonmagnetic carrier supported on said shaft.
Claim 27
Dependent Claim
28 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a thin body of magnetostrictive material on a nonmagnetic annular carrier supported coaxially on said shaft.
Claim 28
Dependent Claim
32 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a thin body of magnetostrictive material on a nonmagnetic annular carrier supported at its opposite ends coaxially on said shaft.
Claim 29
Dependent Claim
32 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a thin body of magnetostrictive material on a nonmagnetic annular carrier clamped at its opposite ends coaxially on said shaft.
Claim 30
Dependent Claim
33 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a thin body of magnetostrictive material on a nonmagnetic annular carrier heat shrunk at its opposite ends coaxially on said shaft.
Claim 31
Dependent Claim
26 words
The noncontact shaft torquemeter of claim 18 wherein said wall element comprises a layer of magnetostrictive material deposited on a nonmagnetic carrier supported on said shaft.
Claim 32
Dependent Claim
155 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed at its opposite ends to the shaft and defining a reduced thickness magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube; means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion; and means associated with said tube for preventing shaft bending and thrust loads from affecting the magnetostrictive condition of said coupling portion.
Claim 33
Dependent Claim
155 words
In a noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, said torquemeter having an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil associated with the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween, the improvement comprising: a tube coaxially fixed at its opposite ends to the shaft and defining a reduced thickness magnetostrictive coupling portion; means associated with said coupling portion for preventing a continuous annular conductive path through said coupling portion of the tube; means for mounting said coil structure coaxially about said coupling portion for coupling said excitation and pickup coil through said coupling portion; and means associated with said tube for preventing shaft bending and thrust loads from affecting the magnetostrictive condition of said coupling portion.
Claim 34
Dependent Claim
27 words
The noncontact shaft torquemeter of claim 26 wherein said coupling portion of the tube comprises a magnetostrictive material bonded to a nonmagnetic carrier portion of the tube.
Claim 35
Dependent Claim
137 words
A noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, comprising: an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil wound about the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween; a circumferentially continuous annular, nonmagnetic support mounted coaxially to the shaft; a circumferentially discontinuous thin annular body of magnetostrictive material coaxially on said support; and means for mounting said coil structure coaxially about said circumferentially discontinuous body at a preselected portion thereof the axial extent of which is substantially greater than the axial extent of said coil structure for preventing a continuous annular conductive path between said coils through said body.
Claim 36
Dependent Claim
137 words
A noncontact shaft torquemeter for use in measuring torque transmission through a rotatable shaft, comprising: an annular torque-sensing coil structure including an annular excitation coil arranged to be disposed coaxially of the shaft and a pickup coil wound about the excitation coil to be magnetically coupled to the excitation coil to provide an output signal varying as a function of variation in the magnetic coupling therebetween; a circumferentially continuous annular, nonmagnetic support mounted coaxially to the shaft; a circumferentially discontinuous thin annular body of magnetostrictive material coaxially on said support; and means for mounting said coil structure coaxially about said circumferentially discontinuous body at a preselected portion thereof the axial extent of which is substantially greater than the axial extent of said coil structure for preventing a continuous annular conductive path between said coils through said body.
Claim 37
Dependent Claim
16 words
The noncontact shaft torquemeter of claim 28 wherein said thin body is bonded to the support.
Claim 38
Dependent Claim
18 words
The noncontact shaft torquemeter of claim 28 wherein said thin body comprises a layer deposited on the support.
Claim 39
Dependent Claim
22 words
The noncontact shaft torquemeter of claim 28 wherein said thin body has an axial extent substantially less than that of said support.
Claim 40
Dependent Claim
31 words
The noncontact shaft torquemeter of claim 28 wherein said thin body has an axial extent substantially less than that of said support and is centered between the ends of the support.
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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) | 1989-10-13 | 1990-04-14 | 1990-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-13 | 1994-04-14 | 1994-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-13 | 1998-04-14 | 1998-10-14 | $7700.00 | Window Closed / Lapsed |