Source: http://www.google.com/patents/US6611790?dq=6,563,928
Timestamp: 2014-07-13 03:08:37
Document Index: 734212151

Matched Legal Cases: ['art 72', 'art 72', 'arts 71', 'arts 71', 'arts 71', 'art 71', 'art 71', 'art 71', 'art 71', 'art 71', 'arts 71', 'art 93', 'art 93', 'art 93', 'art 93', 'arts 91', 'art 93', 'arts 91']

Patent US6611790 - Measuring device for the contactless measurement of an angle of rotation - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA measuring instrument for contactless detection of an angle of rotation γ is comprised of a supporting plate (14) made of soft magnetic material, which serves as a rotor. Two segments (16, 17) that are separated by a slot (21) and a spacing gap (22) are disposed in a plane in relation to the supporting...http://www.google.com/patents/US6611790?utm_source=gb-gplus-sharePatent US6611790 - Measuring device for the contactless measurement of an angle of rotationAdvanced Patent SearchPublication numberUS6611790 B1Publication typeGrantApplication numberUS 09/856,062PCT numberPCT/DE1999/003021Publication dateAug 26, 2003Filing dateSep 22, 1999Priority dateNov 17, 1998Fee statusLapsedAlso published asDE19852915A1, EP1133676A1, WO2000029813A1Publication number09856062, 856062, PCT/1999/3021, PCT/DE/1999/003021, PCT/DE/1999/03021, PCT/DE/99/003021, PCT/DE/99/03021, PCT/DE1999/003021, PCT/DE1999/03021, PCT/DE1999003021, PCT/DE199903021, PCT/DE99/003021, PCT/DE99/03021, PCT/DE99003021, PCT/DE9903021, US 6611790 B1, US 6611790B1, US-B1-6611790, US6611790 B1, US6611790B1InventorsAsta Reichl, Thomas KlotzbuecherOriginal AssigneeRobert Bosch GmbhExport CitationBiBTeX, EndNote, RefManPatent Citations (10), Referenced by (9), Classifications (8), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetMeasuring device for the contactless measurement of an angle of rotationUS 6611790 B1Abstract A measuring instrument for contactless detection of an angle of rotation γ is comprised of a supporting plate (14) made of soft magnetic material, which serves as a rotor. Two segments (16, 17) that are separated by a slot (21) and a spacing gap (22) are disposed in a plane in relation to the supporting plate (14). The supporting plate (14) is attached to the axle (11), whose projection (12) or the axle (11) itself is comprised of magnetically conductive material. The supporting plate (14) has a magnet (15) disposed on it, which is embodied as smaller than the angle of rotation γ to be measured. The magnet (15) can be embodied of one or several parts. Through the disposition of the magnet (15), it is possible to produce different sections in the measurement curve detected by the measurement instrument, e.g. plateaus or sections which deviate from the linear measurement line.
What is claimed is: 1. A measuring instrument for contactless determination of rotational movement of a component, comprising a rotor connectable with a component; a stator rotatable relative to said rotor with an air gap between said stator and said rotor, said stator being composed of at least two segments which are separated by a magnetically non conductive gap; a magnet arranged on said rotor, at least one magnetic field-sensitive element disposed in said magnetically non conductive gap, at least one part of said stator having a magnetically conductive connection to said rotor, said rotor being composed of a magnetically conductive material, said magnet being smaller than an angle of rotation between said stator and said rotor to be measured so that there are two different exclusively ascending slopes in a measuring curve which does not have a change of sign.
PRIOR ART The invention is based on a measuring instrument for contactless detection of an angle of rotation. DE-OS 196 34 281.3 has disclosed a sensor which is disposed in three superposed planes. The rotor constitutes the middle plane, wherein it is comprised of the supporting plate for a permanent magnet. The supporting plate itself is comprised of magnetically nonconductive material so that the magnetic flux travels via the two other planes, i.e. the stator, and is dispersed with the aid of two spacers which are disposed between the two planes of the stator. The shaft or the projections of a shaft that is attached to the rotor has no influence on the magnetic flux. With the sensor, a relatively large angular range can in fact be measured without a change of sign, but it is relatively large in terms of the axial direction due to being constructed of three parallel planes.
ADVANTAGES OF THE INVENTION The measuring instrument for contactless detection of an angle of rotation according to the invention has the advantage over the prior art that the sensor has a relatively small size in the axial direction. It is comprised of only two planes. The supporting plates of the permanent magnet which represents the rotor is simultaneously also used to convey the magnetic flux. Furthermore, the shaft or axle supporting the rotor is included in the conduction of the magnetic flux, as a result of which additional magnetic flux conducting parts are rendered unnecessary. Furthermore, this design reduces the number of parts and the assembly costs involved with them.
BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 show different views of or sections through a first exemplary embodiment.
FIG. 2 shows a section B�B according to FIG. 4,
FIG. 4 is a longitudinal section in the direction A�A according to FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 4, a sensor is labeled 10, which with the aid of an axle 11, is connected to a component, not shown, whose rotational movement is to be determined. A projection 12 is attached to the end face of the axle 11 so that a shoulder 13 is produced on which a supporting plate 14 is centrally placed, which simultaneously serves as a rotor. The axle 11, the projection 12, and the supporting plate 14 can be embodied both as separate components and as a single component. An annular permanent magnet 15 is disposed on the supporting plate 14 with the greatest possible radial distance from the center point, i.e. from the attachment point of the axle 11. The greater this distance, the better the resolution of the measurement signal. The permanent magnet 15 can be embodied as a sector of a circle (circle segment) or part of a circular ring. Its angular range α, however, is smaller than the to-be-determined maximal angle of rotation γ of the component to be monitored and measured. As can be seen from the depictions in FIGS. 2 and 3, the angular range α of the permanent magnet 15 in this exemplary embodiment is approx. 100 degrees; the total working measurement range, however, is γ=180 degrees. The differential angle β would create the plateau P shown in FIG. 11. The permanent magnet 15 is furthermore polarized in the axial direction, i.e. perpendicular to the supporting plate 12. The supporting plate 14 is comprised of magnetically conductive, in particular soft magnetic material. According to the invention, the axle 11 and the projection 12 or at least the projection 12 is comprised of magnetically conductive, in particular soft magnetic material.
FIG. 11 shows the course of the characteristic curve of the magnetic induction B in the element 25, e.g. a Hall element, over the angle of rotation γ of the axle 11. It is clear that with an angle of rotation γ of 0�, the induction B is likewise 0, while at the maximal angle of rotation γ=max, the maximal induction value is also achieved. In this exemplary embodiment, the maximal angle of rotation γ is reached at 180�. The position of the sensor 10 with an angle of rotation of 0� is shown in FIGS. 5 and 6. It is clear that the magnetic flux travels from the permanent magnet 15, via the air gap 100 to the segment 17, from there via the slight gap 20, which allows the rotor to move in relation to the stator, to the projection 12 and from there, via the supporting plate 14, back to the permanent magnet 15. As can be seen in particular in FIG. 6, the magnetic flux is controlled so that with an angle of rotation of 0�, it does not travel through the element 25 so that no magnetic induction B can occur in the element 25. If the axle 11 and hence the supporting plate 14 with the permanent magnet 15 is now rotated, then the magnetic flux traveling through the element 25 is increased and the linear measurement line H shown in FIG. 11 is produced. In FIGS. 5 to 10, it should be noted that the rotor is moving counterclockwise. At the end of the measurement line H, i.e. at point B, the permanent magnet 15 has just passed completely through the gap 21. It also indicates that the permanent magnet 15 is now disposed completely underneath the segment 16. This position B at the angle of rotation α also represents the position of the maximal magnetic flux of the permanent magnet 15 via the gap 21. With further rotation by the angular range β in order to achieve the total rotation range γ no change in the induction B occurs in the measurement gap 21 and consequently in the measurement element 25. As a result, a plateau region P is produced in the graph according to FIG. 11. FIGS. 9 and 10 show the end position at point C after the further rotation by the angle β, i.e. after the total rotation range γ. It is clear, particularly from FIGS. 8 and the gap 21, nearly the entire magnetic flux is conveyed through the element 25 and as a result, a maximal possible magnetic induction B is produced in the element 25. Furthermore, it is also clear from these two FIGS. 8 and 10 that the spacing gap 22 causes nearly all of the magnetic lines to travel via the gap 21 and consequently through the element 25. This means that as close as possible to no magnetic flux can travel through the spacing gap 22.
Whereas a magnetic flux in the preceding exemplary embodiments was controlled via the magnetically conductive projection 2 of the axle 11, in FIGS. 24 to 29 and in the corresponding graph 30, an embodiment of a sensor 70 is shown in which the magnetic flux does not travel via the axle and/or a projection of the axle, but rather is controlled via a return flux part 72 attached to a segment 17 a of the stator that functions as a flux conducting part. It is clear in FIG. 24 that a support 14 b is disposed on the axle 11 a and has the same properties as the support 14 or 14 a in the preceding exemplary embodiments. In a second plane above supporting plate 14 b, which serves as a rotor, there is a stator which is comprised of two segments 16 a and 17 a. A magnetic field-sensitive element 25 a is disposed in the slot 21 a between the two segments 16 a and 17 a. An element of the kind described in the other exemplary embodiments can be used as the magnetic field-sensitive element 25 a. A return flux part 72 is disposed on the segment 17 a and encompasses the entire circular circumference surface of the segment 17 a. It has a length that protrudes beyond the supporting plate 14 b. Like the two segments 16 a and 17 a, it is made of magnetically conductive material. It is also clear from FIG. 25 that the permanent magnet disposed on the supporting plate 14 b is comprised of two parts 71 a and 71 b. The two parts 71 a and 71 b are of the same size, which means that the angular range α1=α2. The measurement range β is once again disposed between the two permanent magnet parts 71 a and 71 b. FIGS. 24 and 25 now show the position with an angle of rotation γ=0� and an induction B=0. With counterclockwise rotation of the axle 11 a and consequently of the supporting plate 14 b, the first magnet part 71 a is moved across the gap 21 a and is disposed to an ever increasing degree in the vicinity of the segment 16 a. FIGS. 26 and 27 now show the position when the measurement range β is disposed over the gap 21 a. As long as the magnet part 71 a is moving underneath the segment 16 a, the characteristic curve rises in linear fashion as shown in FIG. 30. As soon as the entire permanent magnet part 71 a has passed the gap 21 a, the plateau P begins, which corresponds to the measurement range β. As soon as the magnet part 71 b begins to move under the segment 16 a, the measurement line rises again in linear fashion and reaches the maximal induction B=max as soon as the permanent magnet part 71 b, i.e. both permanent magnet parts 71 a and 71 b, are disposed completely underneath the segment 16 a. FIGS. 28 and 29 then show the position of the sensor 70 with a maximal angle of rotation position γ=max and a maximal induction B=max.
FIGS. 31 and 32 now show an embodiment of an angle sensor 80 in which the permanent magnet or the permanent magnet parts are magnetized in the radial direction. In the angle sensor 80, one of the segments 95 is connected by means of a bridge 96 to an outer annular housing part 93. The second segment element 97 has no connection to the housing part 93, i.e. there is no magnetically conductive connection between the segment 97 and the housing part 93. Because of the bridge 96, the angular range to be determined is consequently limited, i.e. it is not possible to take measurements over an angle of approximately 200�. In this embodiment, the segment 95, the bridge 96, and the housing part 93 can advantageously be produced as a one-piece component made of soft magnetic material, e.g. stacked transformer plates or sintered material. Naturally, it is also possible here to embody the segments 95, 97 not only symmetrically but also asymmetrically. The magnetic field-sensitive element 99, which can be embodied the same way as in the above-described exemplary embodiments, is disposed in the slot 98 between the two segments 95 and 97. In the depiction according to FIG. 31, the permanent magnet 91 a, 91 b disposed in the slot 100 embraces the segment 97. This means that the permanent magnet in turn is comprised of at least two permanent magnet parts 91 a and 91 b or of a single permanent magnet which embraces an angular range smaller than the segment 97. The polarization direction of the permanent magnet or the two permanent magnet parts is oriented in the radial direction. This means that the magnetization direction is directed from the segment 97 toward the housing part 93 or in the opposite direction. FIGS. 31 and 32 do not show that the permanent magnet or the two permanent magnet parts 91 a and 91 b are in turn disposed on a supporting plate which is connected to the rotating axle. In this connection, FIG. 31 shows the position of the permanent magnet with an angle of rotation γ=0 and FIG. 32 shows the position with a maximal angle of rotation γ=max. The measurement line produced during the rotating motion corresponds analogously to the characteristic curve shown in FIG. 30.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS6137288 *May 8, 1998Oct 24, 2000Luetzow; Robert HermanMagnetic rotational position sensorCA1232957A1Sep 28, 1984Feb 16, 1988Allan J. HewettRotational sensorDE4103561A1Feb 6, 1991Aug 14, 1991Papst Motoren Gmbh & Co KgRotary position sensor for detecting rotor position - uses magnetic field sensor providing AC signal during rotor rotationDE4123131A1Jul 12, 1991Jan 14, 1993Inst Schiffbautechnik Und UmweRotation-angle dependent electrical output signal generation - measuring magnetic potential differences between pairs of points on arms of rotation symmetrical closed magnetic systemDE19634281A1Aug 24, 1996Feb 26, 1998Bosch Gmbh RobertMe�vorrichtung zur ber�hrungslosen Erfassung eines Drehwinkels bzw. einer linearen BewegungDE19634282A1Aug 24, 1996Feb 26, 1998Bosch Gmbh RobertMe�vorrichtung zur ber�hrungslosen Erfassung eines DrehwinkelsDE19719019A1May 7, 1997Nov 13, 1997Itt Mfg Enterprises IncContactless magnetic sensor for measuring angular displacementDE19731555A1Jul 23, 1997Apr 2, 1998Mannesmann Vdo AgMagnetischer PositionssensorDE19753776A1Dec 4, 1997Jun 10, 1999Bosch Gmbh RobertMe�vorrichtung zur ber�hrungslosen Erfassung eines DrehwinkelsEP0611951A2Feb 11, 1994Aug 24, 1994Kearney-National, Inc.Rotational magnetic sensor* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6799644 *May 1, 2003Oct 5, 2004Hilti AktiengesellschaftPneumatic percussive mechanismUS6822441 *Apr 28, 2004Nov 23, 2004Delphi Technologies, Inc.Half turn vehicle sensor having segmented magnetUS6960974 *Nov 14, 2002Nov 1, 2005Honeywell International Inc.Magnetoresistive smart switchUS7221154Apr 6, 2006May 22, 2007Ksr International Co.Inductive position sensor with common mode corrective winding and simplified signal conditioningUS7292026Apr 7, 2006Nov 6, 2007Ksr International Co.Signal conditioning system for inductive position sensorUS7345473Apr 17, 2007Mar 18, 2008Ksr Technologies Co.Inductive position sensor with common mode corrective winding and simplified signal conditioningUS7463127Mar 11, 2005Dec 9, 2008Honeywell International Inc.Magnetoresistive smart switchUS7821256Sep 30, 2008Oct 26, 2010Ksr Technologies Co.Linear and rotational inductive position sensorUS8350561Jun 27, 2006Jan 8, 2013Ksr Technologies Co.Linear and rotational inductive position sensor* Cited by examinerClassifications U.S. Classification702/163, 324/207.2, 324/207.21International ClassificationG01B7/30, G01D5/14, G01B7/00Cooperative ClassificationG01D5/145European ClassificationG01D5/14B1Legal EventsDateCodeEventDescriptionOct 16, 2007FPExpired due to failure to pay maintenance feeEffective date: 20070826Aug 26, 2007LAPSLapse for failure to pay maintenance feesMar 14, 2007REMIMaintenance fee reminder mailedMay 17, 2001ASAssignmentOwner name: ROBERT BOSCH GMBH, GERMANYFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:REICHL, ASTA;KLOTZBUECHER, THOMAS;REEL/FRAME:011937/0219;SIGNING DATES FROM 20010409 TO 20010410Owner name: ROBERT BOSCH GMBH WERNERSTRASSE 1STUTTGART, (1)D-7Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:REICHL, ASTA /AR;REEL/FRAME:011937/0219;SIGNING DATES FROM 20010409 TO 20010410RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google