Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/443—Devices characterised by the use of electric or magnetic means for measuring angular speed mounted in bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
  • F16C41/007—Encoders, e.g. parts with a plurality of alternating magnetic poles
• • 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
  • G01D5/2006—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 by influencing the self-induction of one or more coils
  • G01D5/202—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 by influencing the self-induction of one or more coils by movable a non-ferromagnetic conductive element
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
  • G01P3/488—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals delivered by variable reluctance detectors
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/49—Devices characterised by the use of electric or magnetic means for measuring angular speed using eddy currents
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
  • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
  • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
  • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C2300/00—Application independent of particular apparatuses
  • F16C2300/02—General use or purpose, i.e. no use, purpose, special adaptation or modification indicated or a wide variety of uses mentioned
• • 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
• • 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
  • G01D2205/77—Specific profiles
  • G01D2205/775—Tapered profiles

Definitions

• the present invention relates to the field of coders capable of cooperating with a sensor for the purpose of detecting a movement, in particular the rotational movement of a rotating part with respect to a non-rotating part.
• the encoder is generally mounted on the rotating part while the sensor is mounted on the non-rotating part, although the mounting is reversed in some applications.
• the sensor is capable of delivering a signal making it possible to determine the value of the parameter to be measured, such as the displacement, the position, the speed or the angular acceleration of the rotating part.
• the active part of the encoder which cooperates with one or more sensors, comprises coding elements whose shape and structure depend on the type of sensor with which the encoder operates.
• the rotating part is a rotating ring of a rolling bearing whose non-rotating ring supports the sensor.
• the invention relates more particularly to metal coders, the operational part of which is made of an electrically conductive material and the geometry of which makes it possible to generate the appropriate signal with the appropriate sensor or sensors, such as inductive microbool sensors.
• metal coders such devices are known, for example from French patent applications No. 0208263 and 0208264, and are satisfactory.
• at least the active part of the encoder is made of metal, generally by cutting and possibly stamping a sheet of metal sheet.
• such an encoder has some drawbacks.
• the encoder has a relatively high mass and inertia, which is rarely desirable.
• An encoder causes a significant imbalance at high speed of rotation.
• the shape of the teeth or windows is not always very rigorous if one wants to use conventional manufacturing processes, such as press cutting for a reasonable cost price.
• Certain shapes of teeth or windows are moreover difficult to produce from a sheet metal blank, due to the complexity of the shape and / or the small dimensions of the teeth or windows.
• the difficulty in obtaining teeth or windows of constant geometry results in irregularities detrimental to the quality of the output signal from the sensor.
• the invention proposes to remedy these drawbacks.
• the invention provides an encoder of low mass, of reduced bulk, substantially free of unbalance, and of economical manufacture.
• the invention proposes an encoder having a great lightness, a low inertia and being able to turn at high speed without imbalance and without friction, whatever the shape of the active part of the encoder whose center of inertia can be located completely outside. of the axis of rotation of the system without consequence on the general imbalance of the coding wheel.
• the instrumented rolling bearing is of the type comprising a non-rotating ring, a rotating ring, at least one row of rolling elements arranged between two raceways of the rotating and non-rotating rings, and a information sensor assembly comprising a non-rotating sensor unit and a rotary encoder provided with an active part.
• the encoder comprises a substrate made of electrically non-conductive material and a thin electrically conductive layer supported by the substrate, the substrate being fixed in rotation with the rotating ring.
• the substrate can be made of synthetic material having a density considerably lower than steel. A reduced mass and inertia encoder is thus obtained.
• the electrically conductive thin layer may have an eccentric shape whose influence on the information of an unbalance is negligible. Indeed, the small thickness of the thin layer compared to the thickness of the substrate means that the overall center of inertia of the annular coding wheel practically does not vary with the shape of the metal deposit and remains located substantially on the axis of rotation.
• the substrate is annular. This reduces any imbalance.
• the substrate may have a general disc shape.
• the substrate of planar shape, can thus be manufactured from a conventional printed circuit board.
• the cost price of the encoder therefore remains reasonable.
• the sensor block comprises at least one inductive sensor.
• the sensor unit can include at least one microbool. It is thus possible to benefit from a sensor unit of reduced bulk.
• the electrically conductive thin layer comprises a plurality of angular sectors separated from each other.
• the electrically conductive thin layer can form a plurality of teeth each occupying a determined angle, constant or not. These teeth can be arranged in one or more concentric rings in order to cooperate with one or more radially stepped sensors.
• the electrically conductive thin layer is circularly continuous.
• the electrically conductive thin layer can be delimited by two circles which are offset from one another. One of the circles may be concentric with the substrate of the encoder. We then benefit from the thin thickness of the thin layer which, despite its eccentricity, does not cause any significant imbalance effect.
• the substrate is fitted onto a bearing surface of the rotating ring. Said bearing surface can be cylindrical and centered on the axis of the rolling bearing. Said bearing surface can be arranged radially between the bottom of the raceway of the rolling elements and the opposite cylindrical surface, for example the bore of a rotating inner ring.
• the substrate is bonded to the rotating ring. This avoids the specific machining of a bearing and uses a standard type rotating ring, particularly economical.
• the substrate is pinched against a radial surface of the rotating ring.
• the substrate can be pinched between said radial surface of the rotating ring and a radial surface formed by a step of the housing or of the shaft of the rotating ring.
• the device comprises an encoder support, mounted on a cylindrical surface of the rotating ring.
• the encoder support can be made of synthetic material, of low density, or even of light metal alloy.
• the encoder support can be fitted on the rotating ring, for example in the bore of an outer ring or on the outer cylindrical surface of an inner ring, of standard type.
• the encoder support can also be glued to the rotating ring or even be pinched against the rotating ring.
• the present invention also provides an encoder provided with an active part and intended for an information sensor assembly further comprising a sensor block capable of cooperating with the encoder.
• the encoder comprises a substrate of electrically non-conductive material and a thin electrically conductive layer supported by the substrate.
• the thin layer is made of copper with possibly a very thin finishing layer of gold or silver. But we can also consider making the thin layer of any other electrically conductive metal that can be deposited, and, if necessary, etched on a printed circuit board.
• the thin layer is between 5 and 100 microns thick. The invention therefore offers a particularly light encoder, easy to mount on a rotating part and whose harmful influence on any imbalance is completely negligible.
• FIG. 1 is a view in axial section of a rolling bearing according to a first embodiment of the invention
• FIG. 2 is a front elevation view of an encoder according to one aspect of the invention
• FIGS. 3 and 4 show variants of FIG. 2
• FIGS. 5 to 8 are half-views in axial section of a rolling bearing according to different embodiments of the invention. As illustrated in FIG.
• the rolling bearing 1 comprises an outer ring 2, an inner ring 3, a row of rolling elements 4, here balls, arranged between the outer ring 2 and the inner ring 3, and held by a cage 5, a seal 6 secured to the outer ring 2 and rubbing against the inner ring 3, a sensor 7 secured to the outer ring 2 and an encoder 8 secured to the inner ring 3.
• the outer ring 2 will generally be a non-rotating ring, while the inner ring 3 will be used as a rotating ring. However, in certain applications, it is desired to benefit from rotation information on a rotating part.
• the encoder is then arranged integral with the non-rotating ring, while the sensor is mounted integral with the rotating ring.
• the outer ring 2 is of the massive type, comprising a toroidal raceway 2a for the rolling elements 4, an outer cylindrical surface 2b, front radial surfaces 2c and
• the inner ring 3 has a toroidal raceway 3a for the rolling elements 4, a cylindrical bore 3b, radial front surfaces 3c and 3d, respectively coplanar with the radial surfaces 2c and 2d of the outer ring 2, and an outer cylindrical surface 3rd.
• a cylindrical bearing surface 3f is formed, by machining, from the external cylindrical surface 3e while being adjacent to the radial surface 3d.
• the diameter of the bearing surface 3f is between the diameter of the bore 3b and the diameter of the bottom of the raceway 3a to provide a radial space for the encoder 8.
• the sensor 7 comprises a metal support 11, of generally annular shape, provided of a hook part 11a projecting in the groove 10 of the outer ring 2, a radial part 1 1b in contact with the radial surface 2d of the outer ring 2, and a substantially axial part connected extending outwards from the large diameter end of the radial part 1 1b.
• the sensor 7 further comprises a body 12 made of synthetic material and having a generally annular shape.
• the body 12 is surrounded radially by the axial part binds from the support 1 1 and has a wired terminal 12a projecting outwardly to pass an electrical cable 13.
• the wired terminal is disposed in a notch formed in the part axial link of the support 1 1.
• the sensor 7 is completed by a printed circuit board 14 occupying a limited angular sector, and disposed in the body 12 while being exposed on the side of the rolling elements 4, and of the electronic components 15, in particular of the microbins, arranged on the face of the printed circuit board 14, on the side of the rolling elements 4.
• the encoder 8 comprises a substrate 16 in the form of a flat ring, produced from a printed circuit board, for example made of resin epoxy, and an electrically conductive thin layer 17, for example made of copper, formed on one face of the substrate 16 which is electrically non-conductive.
• the encoder 8 is mounted by fitting the bore of the substrate 16 on the cylindrical surface 3f of the inner ring 3, the thin layer 17 facing the sensor 7 and in particular the electronic component 15.
• the electrically conductive thin layer 17 is in the form of a plurality of distinct zones separated from each other, delimited in the radial direction by two concentric circles with the substrate 16, and occupying in the circumferential direction an angle constant, of the order of 9 °.
• the substrate 16 remains bare, devoid of electrically conductive elements.
• the encoder 8 comprises a substrate 16 identical to that of the preceding embodiment, and a thin electrically conductive layer 17 formed of zones 19 and 20.
• the zones 19 are delimited radially by two circles concentric with the substrate 16, having a diameter greater than the two circles concentric with the substrate 16 delimiting the zones 20.
• the zones 19 and 20 are thus spaced radially and can occupy redundant angular sectors. In other words, the zones 19 and 20 overlap angularly.
• the substrate 16 remains bare, devoid of electrically conductive elements. In the embodiment illustrated in FIG.
• the electrically conductive thin layer 17 occupies a single zone 21, of circular shape, delimited internally by a circle concentric with the substrate 16 and externally by a circle eccentric with respect to the interior circle.
• the zone 21 therefore has a large offset, its maximum radial height possibly being more than twice greater than its minimum radial height. Since the thickness of the thin layer 17 is generally less than 100 microns, the influence on any imbalance is completely negligible, which would not be the case with a solid metal coding wheel.
• the rolling bearing is similar to that of FIG. 1, except that the ring interior 3 is of standard type, without machined surface 3f.
• the inner ring 3 is mounted on a shaft 22 having an outer cylindrical surface 23 limited by a radial shoulder 24.
• the encoder 8 the bore of which is of dimension substantially equal to the bore 3b of the inner ring 3, is mounted on the cylindrical surface 23 of the shaft 22, in contact on one side with the radial shoulder 24, and on the other side with the radial surface 3b of the inner ring 3.
• the radial surface 3c of the inner ring 3 is in contact with a washer or a spacer 25 which a clamping member, not shown, such as a nut, comes to clamp axially against the face
• the encoder 8 is similar to that of Figure 5 with a bore substantially equal to the bore of the inner ring 3.
• the substrate 16 is here bonded to the surface 3d radial of the inner ring 3 and integral with the bearing 1 before mounting on a shaft.
• the rolling bearing 1 further comprises an encoder support 26, made of synthetic material, for example elastomer, of generally annular shape.
• the support 26 comprises a radial wall 26a projecting inwards and in contact with the radial surface 3d of the inner ring 3, an axial wall 26b connecting to the large diameter end of the radial wall 26a and fitted on the cylindrical outer surface 3 e of the inner ring 3, a radial wall 26c connecting to the axial wall 26b near the rolling elements 4 and extending outwards and an axial wall 26d connecting to the large diameter end of the radial wall 26c and extending opposite the rolling elements 4.
• the axial walls 26b, radial 26c and axial 26d define an annular housing in which the encoder 8 is arranged, the substrate 16 of which may be of small axial dimension and radial.
• the radial wall 26a allows precise axial positioning of the encoder 8 and of the support 26 relative to the inner ring 3.
• the axial wall 26b allows the fitting on the inner ring 3.
• the axial walls 26b and 26d form axial retaining means of the encoder 8, while the radial wall 26c forms a means of precise axial positioning of the encoder 8, allowing its cooperation with a sensor from which it is separated by a reduced air gap.
• the embodiment illustrated in FIG. 8 is similar to the previous one, except that the support 26, made of metal, for example of light alloy, comprises radial walls 26a and axial 26b similar to those illustrated in FIG. 7, while that the radial wall
• a coding wheel for a rolling bearing is thus obtained having a very low inertia, the metallized active part of which can be produced with very high precision and is not limited by the complexity of the shapes, hence an increase in the accuracy of the sensor output signal.
• the use of more complex shapes, such as those illustrated in FIG. 3, makes it possible to increase the number of sensors and thereby increase the precision of the detection.
• the active part which is very thin, has a negligible influence on any imbalance.
• the encoder structure allows it to be easily mounted in a rolling bearing. Of course, it is understood that the sensor and the encoder are without mutual contact. A sensor and an encoder with mechanical contact would produce unacceptable heating and destruction of the encoder.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rolling Contact Bearings (AREA)
• Support Of The Bearing (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

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ID=33515455

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (10)

Family Cites Families (73)

• 2003
  • 2003-06-27 FR FR0307772A patent/FR2856757B1/fr not_active Expired - Fee Related
• 2004
  • 2004-06-22 WO PCT/FR2004/001557 patent/WO2005001301A2/fr not_active Ceased
  • 2004-06-22 EP EP04767413A patent/EP1639375A2/fr not_active Withdrawn
  • 2004-06-22 US US10/562,476 patent/US20070053622A1/en not_active Abandoned
  • 2004-06-22 JP JP2006516310A patent/JP2007514924A/ja active Pending

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