GB2231161A - Improvements relating to rotary position transducers - Google Patents
Improvements relating to rotary position transducers Download PDFInfo
- Publication number
- GB2231161A GB2231161A GB9009843A GB9009843A GB2231161A GB 2231161 A GB2231161 A GB 2231161A GB 9009843 A GB9009843 A GB 9009843A GB 9009843 A GB9009843 A GB 9009843A GB 2231161 A GB2231161 A GB 2231161A
- Authority
- GB
- United Kingdom
- Prior art keywords
- secondary coils
- primary coil
- rotor
- transducer
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000008878 coupling Effects 0.000 claims abstract description 6
- 238000010168 coupling process Methods 0.000 claims abstract description 6
- 238000005859 coupling reaction Methods 0.000 claims abstract description 6
- 230000005294 ferromagnetic effect Effects 0.000 claims description 2
- 230000001939 inductive effect Effects 0.000 claims description 2
- 230000006698 induction Effects 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
- G01D5/22—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils
- G01D5/2208—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the self-induction of the coils
- G01D5/2216—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the self-induction of the coils by a movable ferromagnetic element, e.g. a core
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
- G01D2205/70—Position sensors comprising a moving target with particular shapes, e.g. of soft magnetic targets
- G01D2205/73—Targets mounted eccentrically with respect to the axis of rotation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
A rotary position transducer has a fixed primary coil (6) energized with AC and substantially coaxial with the rotor shaft (4), and two fixed secondary coils (8, 9) symmetrically disposed on opposite sides of the primary coil axis with their common axis at right angles to that of the primary coil. An asymmetrical rotor (4, 5) aligned with that axis provides the induction coupling and the asymmetry causes the combined output of the secondary coils (8, 9) to vary, possibly linearly, with the angular position of the rotor (4,5). The secondary coils may be connected in opposition. <IMAGE>
Description
Improvements relating to Rotary Position Transducers his invention relates to rotary position transducers, and in particular transducers in which electromagnetic coupling between primary and secondary coils is varied according to the angular position of a rotor. In such transducers, the primary coil is generally energized with AC and induces corresponding current in the secondary coil which varies as the rotor rotates.
There are many different examples of such transducers and it is common to have more than one secondary coil. It is the aim of this invention to provide yet another transducer which may be of particularly compact form, of simple construction, and with a good degree of accuracy.
According to the present invention there is provided a rotary position transducer comprising a primary coil for AC energization and secondary coils inductively coupled thereto, the secondary coils being co-axial and on opposite sides of the axis of the primary coil, and a rotor extending generally along the primary coil axis and adapted to provide part of the inductive coupling but with an asymmetry that causes the combined outputs of the secondary coils induced by the AC in the primary coils to vary with the angular position of the rotor.
Preferably, the secondary coils will be symmetrical with respect to the primary coil axis but they will be connected in electrical opposition so that their combined outputs provide an enhanced signal, indicating position or movement of the rotor, as compared with what would be available from a single coil.
The rotor may be a shaft co-axial with the primary coil but with a ferromagnetic sleeve with eccentric configuration spanning the centre of the primary coil and the mutual centre of the secondary coils. The asymmetry of the rotor, and in particular of the sleeve, may be configured to give a desired output characteristic and in particular it may be possible to generate an output from the secondary coils that varies linearly over at least part of the rotational cycle.
For a better understanding of the invention one embodiment will now be described, by way of example, with reference to the accompanying drawing, in which:
Figure 1 is an axial section of a rotary position transducer, and
Figure 2 is a cross-section of the transducer on the line II-II of Figure 1.
The transducer is of generally cylindrical form and has a body comprising a cup-like shell 1 with an end cap 2. The base of the shell 1 and the centre of the cap 2 are fitted with bearings 3 for a shaft 4 co-axial with the body. A sleeve 5 of ferromagnetic material is carried by the shaft 4 between the bearings 3 and it is of eccentric cross-section as best seen in Figure 2. Together the shaft 4 and sleeve 5 form what will be referred to later as the rotor.
Near the base of the shell 1, and within it coaxially surrounding the shaft 4, there is a primary coil 6 which, in use, will be energized by AC.
Occupying most of the remaining space within the shell 1 and also surrounding the shaft 4 there is a carrier 7 with two secondary coils 8 and 9 co-axially wound into annular recesses symmetrically on opposite sides of the primary coil axis. Their common axis is perpendicular to the axis of the primary coil 6 and intersects it near one end of the sleeve 5. The carrier 7 provides stepped bores for cores 10 and 11 co-axial with the coils 8 and 9, these cores providing part of a flux path through the sleeve 5 which is continued back to the other end of the sleeve adjacent the base of the shell 1 by the shell itself.
The secondary coils 8 and 9 are wound in opposite directions or at least their outputs are connected in electrical opposition. The leads are not shown but may be taken out through a hole 12 in the cap 2, and the AC supply to the primary coil 6 may pass into the body at this point.
It will be seen, especially from Figure 2, that in the illustrated position of the rotor the electromagnetic coupling to the coil 9 will be better than that to.the coil 8. There will therefore be a differential output from the secondary coils indicative of the angular position of the rotor.
As that rotates, so the coupling to the secondary coils alters, and so does their combined output, which will give an accurate indication of the rotor position throughout 36goo
Claims (5)
1. A rotary position transducer comprising a primary coil for AC energization and secondary coils inductively coupled thereto, the secondary coils being co-axial and on opposite sides of the axis of the primary coil, and a rotor extending generally along the primary coil axis and adapted to provide part of the inductive coupling but with an asymmetry that causes the combined outputs of the secondary coils induced by the
AC in the primary coils to vary with the angular position of the rotor.
2. A transducer as claimed in claim 1, wherein the secondary coils are symmetrical with respect to the primary coil axis, but are connected in electrical opposition so that their combined outputs provide an enhanced signal as compared with that available from a single coil.
3. A transducer as claimed in claim 1 or 2, wherein the rotor comprises a shaft co-axial with the first coil and carrying a ferromagnetic sleeve with eccentric configuration spanning the centre of the primary coil and the mutual centre of the secondary coils.
4. A transducer as claimed in claim 1,2 or 3, wherein the asymmetry of the rotor is configured to generate a linearly varying output from the secondary coils over at least part of the rotational cycle.
5. A rotary position transducer substantially as hereinbefore described with reference to the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB898910143A GB8910143D0 (en) | 1989-05-03 | 1989-05-03 | Improvements relating to rotary position transducers |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9009843D0 GB9009843D0 (en) | 1990-06-27 |
| GB2231161A true GB2231161A (en) | 1990-11-07 |
Family
ID=10656138
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898910143A Pending GB8910143D0 (en) | 1989-05-03 | 1989-05-03 | Improvements relating to rotary position transducers |
| GB9009843A Withdrawn GB2231161A (en) | 1989-05-03 | 1990-05-02 | Improvements relating to rotary position transducers |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898910143A Pending GB8910143D0 (en) | 1989-05-03 | 1989-05-03 | Improvements relating to rotary position transducers |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB8910143D0 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994014027A1 (en) * | 1992-12-12 | 1994-06-23 | Penny & Giles Blackwood Limited | Rotary transducer |
| US6374664B1 (en) * | 2000-01-21 | 2002-04-23 | Delphi Technologies, Inc. | Rotary position transducer and method |
| WO2004091244A1 (en) | 2003-04-07 | 2004-10-21 | Fujitsu Limited | Dual mode system and dual mode radio termial |
| US20120098527A1 (en) * | 2007-05-10 | 2012-04-26 | Cambridge Integrated Circuits Limited | Transducer |
| US9410791B2 (en) | 2010-12-24 | 2016-08-09 | Cambridge Integrated Circuits Limited | Position sensing transducer |
| US9470505B2 (en) | 2012-06-13 | 2016-10-18 | Cambridge Integrated Circuits Limited | Position sensing transducer |
| WO2018206714A1 (en) * | 2017-05-12 | 2018-11-15 | Rheinmetall Air Defence Ag | Measuring arrangement for measuring a rotary position and/or a rotation speed of a crankshaft |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110986754B (en) * | 2019-12-13 | 2022-01-14 | 中国航空工业集团公司金城南京机电液压工程研究中心 | Differential transformer type angular displacement sensor |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB908523A (en) * | ||||
| GB1482705A (en) * | 1973-10-19 | 1977-08-10 | Hitachi Ltd | Electrical rotation transducers |
-
1989
- 1989-05-03 GB GB898910143A patent/GB8910143D0/en active Pending
-
1990
- 1990-05-02 GB GB9009843A patent/GB2231161A/en not_active Withdrawn
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB908523A (en) * | ||||
| GB1482705A (en) * | 1973-10-19 | 1977-08-10 | Hitachi Ltd | Electrical rotation transducers |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994014027A1 (en) * | 1992-12-12 | 1994-06-23 | Penny & Giles Blackwood Limited | Rotary transducer |
| US5621179A (en) * | 1992-12-12 | 1997-04-15 | Penny & Giles Blackwood Limited | Rotary transducer |
| US6374664B1 (en) * | 2000-01-21 | 2002-04-23 | Delphi Technologies, Inc. | Rotary position transducer and method |
| WO2004091244A1 (en) | 2003-04-07 | 2004-10-21 | Fujitsu Limited | Dual mode system and dual mode radio termial |
| US20120098527A1 (en) * | 2007-05-10 | 2012-04-26 | Cambridge Integrated Circuits Limited | Transducer |
| US8570028B2 (en) * | 2007-05-10 | 2013-10-29 | Cambridge Integrated Circuits Limited | Transducer for a position sensor |
| US9410791B2 (en) | 2010-12-24 | 2016-08-09 | Cambridge Integrated Circuits Limited | Position sensing transducer |
| US9470505B2 (en) | 2012-06-13 | 2016-10-18 | Cambridge Integrated Circuits Limited | Position sensing transducer |
| WO2018206714A1 (en) * | 2017-05-12 | 2018-11-15 | Rheinmetall Air Defence Ag | Measuring arrangement for measuring a rotary position and/or a rotation speed of a crankshaft |
| WO2018206707A1 (en) * | 2017-05-12 | 2018-11-15 | Rheinmetall Air Defence Ag | Measuring arrangement for measuring a position and/or a rotational speed of a shaft |
| DE102018108019B4 (en) | 2017-05-12 | 2021-10-14 | Rheinmetall Air Defence Ag | Measuring arrangement for measuring a rotational position and / or a speed of a crankshaft |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9009843D0 (en) | 1990-06-27 |
| GB8910143D0 (en) | 1989-06-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |