US3556150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro hydraulic servovalve
Assignee: BW IP International Inc
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Filing: 1969-05-12
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Granted: 1971-01-19
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Expires: 1989-05-12
Abstract
Abstract An electrohydraulic servovalve including a signal responsive torque motor having at least one high energy permanent magnet providing a magnetic flux field. A flux field shunt is affixed to the magnet to compensate for the effects of temperature on servovalve operating characteristics to ensure a consistent hydraulic output function in relation to a given input signal over a wide range of operating temperatures.
Inventors
- 👤 Donald A King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:58
CPC Classifications
F; F15; F15B; F15B5/00; F15B5/003; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; F15B13/0438; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/14; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/8659; Y10T137/86598; Y10T137/86815
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
195 words
An electrohydraulic servovalve including a main valve body defining a divided fluid path, a pair of nozzles disposed in spaced apart facing relation, each one of said nozzles being in fluid communication with a separate portion of said fluid path, a flapper having an end portion positioned intermediate said nozzles and movable toward and away from each said nozzle to control the flow of fluid in each portion of said divided flow path, said flapper including an opposite end defining an armature, and a torque motor secured to said valve body to effect movement of said flapper, said torque motor including at least one permanent magnet to provide a permanent magnet flux field acting upon said armature, and at least one electric coil responsive to an electrical input signal to provide a variable flux field acting upon said armature to vary the position of said flapper, said torque motor including at least one compensating shunt made of permeable material affixed to said permanent magnet in contact therewith to bypass a portion of said permanent magnet flux field at low temperature and being responsive to temperature to reduce the amount of flux bypassed as temperature increases.
Claim 2
Dependent Claim
195 words
An electrohydraulic servovalve including a main valve body defining a divided fluid path, a pair of nozzles disposed in spaced apart facing relation, each one of said nozzles being in fluid communication with a separate portion of said fluid path, a flapper having an end portion positioned intermediate said nozzles and movable toward and away from each said nozzle to control the flow of fluid in each portion of said divided flow path, said flapper including an opposite end defining an armature, and a torque motor secured to said valve body to effect movement of said flapper, said torque motor including at least one permanent magnet to provide a permanent magnet flux field acting upon said armature, and at least one electric coil responsive to an electrical input signal to provide a variable flux field acting upon said armature to vary the position of said flapper, said torque motor including at least one compensating shunt made of permeable material affixed to said permanent magnet in contact therewith to bypass a portion of said permanent magnet flux field at low temperature and being responsive to temperature to reduce the amount of flux bypassed as temperature increases.
Claim 3
Dependent Claim
27 words
An electrohydraulic servovalve as claimed in claim 1 wherein said compensating shunt is in contact with said permanent magnet at the maximum potential portion of said magnet.
Claim 4
Dependent Claim
53 words
An electrohydraulic servovalve as claimed in claim 2 wherein said compensating shunt is generally rectangular and includes opposite end portions deformed slightly in a direction toward said magnet and wherein said shunt is affixed to said magnet with said deformed end portions thereof in contact with the maximum potential portions of said magnet.
Claim 5
Dependent Claim
123 words
An electrohydraulic servovalve as claimed in claim 1 wherein said torque motor includes a pair of permanent magnets disposed in spaced apart relation, a pair of pole pieces of magnetic material contacting said magnets at the maximum potential portions thereof, said pole pieces including opposite end portions disposed in facing spaced relation defining air gaps therebetween and a portion of said armature of said flapper iS disposed in said air gap, said torque motor further including a pair of said electrical coils each one of said coils surrounding a portion of said armature adjacent said portions thereof disposed in one of said air gaps, and a pair of said compensating shunts, each one of which is affixed to one of said permanent magnets.
Claim 6
Dependent Claim
112 words
A torque motor for an electrohydraulic servovalve having a flapper movable to control the flow of fluid therethrough including an armature, said torque motor including at least one permanent magnet to provide a permanent magnet flux field acting upon the armature and at least one electric coil responsive to an electrical input signal to provide a variable flux field acting upon the armature, said torque motor including at least one compensating shunt made of permeable material affixed to said permanent magnet in contact therewith to bypass a portion of said permanent magnet flux field at low temperature and being responsive to temperature to reduce the amount of flux bypassed as temperature increases.
Claim 7
Dependent Claim
112 words
A torque motor for an electrohydraulic servovalve having a flapper movable to control the flow of fluid therethrough including an armature, said torque motor including at least one permanent magnet to provide a permanent magnet flux field acting upon the armature and at least one electric coil responsive to an electrical input signal to provide a variable flux field acting upon the armature, said torque motor including at least one compensating shunt made of permeable material affixed to said permanent magnet in contact therewith to bypass a portion of said permanent magnet flux field at low temperature and being responsive to temperature to reduce the amount of flux bypassed as temperature increases.
Claim 8
Dependent Claim
27 words
A torque motor as claimed in claim 5 wherein said compensating shunt is in contact with said permanent magnet at the maximum potential portions of said magnet.
Claim 9
Dependent Claim
53 words
A torque motor as claimed in claim 6 wherein said compensating shunt is generally rectangular and includes opposite end portions deformed slightly in a direction toward said magnet and wherein said shunt is affixed to said magnet with said deformed end portions thereof in contact with the maximum potential portions of said magnet.
Claim 10
Dependent Claim
124 words
A torque motor as claimed in claim 5 wherein said torque motor includes a pair of permanent magnets disposed in spaced apart relation, a pair of pole pieces of magnetic material contacting said magnets at the maximum potential portions thereof, said pole pieces including opposite end portions disposed in facing spaced relation defining air gaps therebetween and a portion of said armature of said flapper is disposed in each said air gap, said torque motor further including a pair of said electrical coils each one of said coils surrounding a portion of said armature adjacent said portions thereof disposed in one of said air gaps, and a pair of said compensating shunts, each one of which is affixed to one of said permanent magnets.
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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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |