EP0182322A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Rotational position detection device
Assignee: SG KK
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Filing: 1985-11-16
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Granted: —
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Expires: 2005-11-16
Abstract
Abstract The rotational position detection device comprises a stator section (1) including primary and secondary windings (W1, W2) and a rotor section (2) disposed in such a manner that it is capable of performing relative rotational displacement with respect to the stator section. A conductive substance portion (2b) is provided in the form of a predetermined pattern. The amount of flux passing through the conductive substance portion of the rotor section (2) changes in accordance with a relative rotational position of the rotor section with respect to the stator section (1) and therefore an eddy current flows through the conductive substance portion. Reluctance is caused to change by a loss due to this eddy current and a secondary output signal corresponding to the rotational position is produced in the windings of the stator section. The pattern of the conductive substance portion (2b) can be formed easily by using electro-plating or other surface processing technique. The rotor section (2) may be of a shape such that the rate of the reluctance change is enhanced by the combination of the magnetic substance portion (2a) and the conductive substance portion.
Inventors
- 👤 Wataru Ichikawa
- 👤 Yuji Matsuki
- 👤 Takeo Maruyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:39
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/22; G01D5/225; H; H02; H02K; H02K29/00; H02K29/06; H02K29/12; G01D2205/00; G01D2205/70; G01D2205/73
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A rotational position detection device comprising a stator section including winding means being excited by one or more primary AC signals for producing a secondary output, and a rotor section disposed in such a manner that it is capable of performing relative rotational displacement with respect to said stator section, said rotor section comprising a conductive substance portion provided in a predetermined pattern, whereby an eddy _current corresponding to a relative rotational position of said rotor section with respect to said stator section flows in said conductive substance portion and. a corresponding secondary output signal is derived from said winding means.
Claim 2
Dependent Claim
101 words
A rotational position detection device comprising a stator section including winding means being excited by one or more primary AC signals for producing a secondary output, and a rotor section disposed in such a manner that it is capable of performing relative rotational displacement with respect to said stator section, said rotor section comprising a conductive substance portion provided in a predetermined pattern, whereby an eddy _current corresponding to a relative rotational position of said rotor section with respect to said stator section flows in said conductive substance portion and. a corresponding secondary output signal is derived from said winding means.
Claim 3
Dependent Claim
38 words
A rotational position detection device as defined in claim 1 wherein said conductive substance portion is formed by depositing a predetermined conductive substance on a base member of said rotor section by a predetermined surface processing technique. -
Claim 4
Dependent Claim
18 words
A rotational position detection device as defined in claim 2 wherein said conductive substance is deposited by electro-plating.
Claim 5
Dependent Claim
18 words
A rotational position detection device as defined in claim 2 wherein-said conductive substance is deposited by flame spraying.
Claim 6
Dependent Claim
19 words
A rotational position detection device as defined in claim 2 wherein said conductive substance is deposited by pattern baking.
Claim 7
Dependent Claim
56 words
A rotational position detection device as defined in claim 1 wherein said conductive substance portion is formed by depositing a predetermined conductive substance on a base member of said rotor section by electro-plating and then removing an unnecessary portion of said conductive substance deposited on said base member leaving said predetermined pattern of said conductive substance.
Claim 8
Dependent Claim
50 words
A rotational position detection device as defined in claim 6 wherein a predetermined coating material resistive to an agent used for the removing is applied to the base member of said rotor section and said conductive substance is deposited on said base member through said coating material by the electro-plating.
Claim 9
Dependent Claim
24 words
A rotational position detection device as defined in claim 1 wherein said base member of said rotor section is made of a magnetic substance.
Claim 10
Dependent Claim
26 words
A rotational position detection device as defined in claim 1 wherein said base member of said rotor section is made of a non-magnetic and non-conductive substance.
Claim 11
Dependent Claim
58 words
A rotational position detection device as defined in claim 1 wherein said base member of said rotor section is made of a magnetic substance, a shape corresponding to said pattern is formed as a recess in said base member and a conductive substance portion is provided in said recess to form said pattern of said conductive substance portion.
Claim 12
Dependent Claim
69 words
A rotational position detection device as defined in claim 1 wherein said winding means comprises a plurality of primary windings and secondary winding means, said respective primary windings are excited by using primary AC signals which are shifted in phase from each other and signals derived by phase-shifting said primary AC signals in response to the rotational position of said rotor section is produced from said secondary winding means.
Claim 13
Dependent Claim
62 words
A rotational position detection device as defined in claim 1 which further comprises: AC signal generation means for generating the respective primary AC signals; and phase difference detection means for detecting phase difference between one of primary AC signals and the output signal of the secondary winding means to obtain detected phase difference data as rotational position data of said rotor section.
Claim 14
Dependent Claim
36 words
A rotational position detection device as defined in claim 1 wherein predetermined non-magnetic and non-conductive substance is applied over the entire periphery of said rotor section having said conductive substance portion on the peripheral surface thereof.
Claim 15
Dependent Claim
150 words
A rotational position detection device comprising a stator section including winding means being excited by one or more primary AC signals for producing a secondary output, and a rotor section disposed in such a manner that it is capable of performing relative rotational displacement with respect to said rotor section, said rotor section comprises a magnetic substance portion provided in a predetermined part of said rotor section and changing reluctance of a magnetic circuit passing through said winding means in accordance with a rotational position - of said rotor section relative to said stator section; and a conductive substance portion provided in part of said rotor section where the reluctance is caused to increase relatively in such a manner that an eddy current path will be formed relative to flux and made of substance which is relatively weak magnetic or non-magnetic and relatively conductive as compared with said magnetic substance.
Claim 16
Dependent Claim
150 words
A rotational position detection device comprising a stator section including winding means being excited by one or more primary AC signals for producing a secondary output, and a rotor section disposed in such a manner that it is capable of performing relative rotational displacement with respect to said rotor section, said rotor section comprises a magnetic substance portion provided in a predetermined part of said rotor section and changing reluctance of a magnetic circuit passing through said winding means in accordance with a rotational position - of said rotor section relative to said stator section; and a conductive substance portion provided in part of said rotor section where the reluctance is caused to increase relatively in such a manner that an eddy current path will be formed relative to flux and made of substance which is relatively weak magnetic or non-magnetic and relatively conductive as compared with said magnetic substance.
Claim 17
Dependent Claim
49 words
A rotational position detection device as defined in claim 14 wherein said magnetic substance portion is formed as a projection in a magnetic substance member constituting a base of said rotor section and said conductive substance portion is provided in a recessed portion of said magnetic substance member. -
References Cited (Backward Citations)
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