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US4506554A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetoelastic torque transducer

Assignee: ABB Norden Holding AB
•
Filing: 1983-06-07
•
Granted: 1985-03-26
•
Expires: 2003-06-07
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Abstract

Abstract A torque transducer comprises a sleeve of magnetic material, which is attached concentrically and rigidly to an axle, and at least two stationary windings for excitation of the axle and two windings for sensing the torque transmitted by the axle, as well as a magnetic housing concentrically surrounding the windings. The sleeve is formed with two parallel, annular zones, which are provided with slits having a substantially regular pitch and making an angle of ±45° with a generatrix of the envelope surface of the sleeve. The excitation windings are series-connected and generate a magnetic flux in the axle surface. The measuring windings are connected in opposition, whereby the measuring signal is approximately zero in case of zero torque in the axle. When the axle is subjected to a torque, the bars between the slits in the annular zones will be subjected to tensile stress and compressive stress, respectively, in the direction of the flux. This leads to a polarized magnetic unbalance, which results in a difference voltage from the measuring windings which, after phase-sensitive detection, gives a measure of the magnitude and sign of the torque.

Inventors

  • 👤 Kent Blomkvist
  • 👤 Jan O. Nordvall

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 22:04
CPC Classifications
G; G01; G01L; G01L3/00; G01L3/02; G01L3/04; G01L3/10; G01L3/101; G01L3/102; G01L3/105

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 171 words
A magnetoelastic torque transducer comprising: an axle provided with a soft-magnetic sleeve permanently attached to said axle, said sleeve having two parallel, ring-formed measuring zones at a certain distance from each other, each measuring zone being formed by a number of parallel slits which in one of said measuring zones make an angle of about 45° with a generating line of the sleeve surface and in the other measuring zone make an angle of about -45° with said line, two stationary coils, each concentric with one of said measuring zones, said coils arranged to be series-fed with alternating current for inducing an alternating magnetic flux in said sleeve, two other stationary coils, each concentric with one of said two stationary coils, these other coils connected in series opposition to a phase sensitive rectifier connected to an indicating instrument, and a core of soft-magnetic material concentric with said axle, said core together with said sleeve closing said magnetic flux and with a middle wall separating the two zones and their respective coils.
Claim 2
Dependent Claim 171 words
A magnetoelastic torque transducer comprising: an axle provided with a soft-magnetic sleeve permanently attached to said axle, said sleeve having two parallel, ring-formed measuring zones at a certain distance from each other, each measuring zone being formed by a number of parallel slits which in one of said measuring zones make an angle of about 45° with a generating line of the sleeve surface and in the other measuring zone make an angle of about -45° with said line, two stationary coils, each concentric with one of said measuring zones, said coils arranged to be series-fed with alternating current for inducing an alternating magnetic flux in said sleeve, two other stationary coils, each concentric with one of said two stationary coils, these other coils connected in series opposition to a phase sensitive rectifier connected to an indicating instrument, and a core of soft-magnetic material concentric with said axle, said core together with said sleeve closing said magnetic flux and with a middle wall separating the two zones and their respective coils.
Claim 3
Dependent Claim 18 words
A magnetoelastic torque transducer according to claim 1, in which said sleeve is made of rolled tube material.
Claim 4
Dependent Claim 32 words
A magnetoelastic torque transducer according to claim 1, in which said sleeve is attached to an external cylindrical surface of said axle and said coils and said core surround said sleeved axle.
Claim 5
Dependent Claim 35 words
A magnetoelastic torque transducer according to claim 1, in which said sleeve is attached to an internal cylindrical surface in a hollow axle and said coils and said core are surrounded by said hollow axle.
Claim 6
Dependent Claim 37 words
A magnetoelastic torque transducer according to claim 1, in which said sleeve is formed by attaching a strip of magnetic material around said axle, said strip being formed with slits in the same pattern as said sleeve.

References Cited (Backward Citations)

US2553833A Cited
US3011340A Cited
US3465581A Cited
DE1900194A1 Cited
SU667836A1 Cited
SU838448A1 Cited
US4306462A Cited
US4414855A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-03-25 1988-09-24 1989-03-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-03-25 1992-09-24 1993-03-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-03-25 1996-09-24 1997-03-26 $7700.00 Window Closed / Lapsed

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