Classifications

• • 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
  • F16C41/002—Conductive elements, e.g. to prevent static electricity
• • 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
  • F16C19/52—Bearings with rolling contact, for exclusively rotary movement with devices affected by abnormal or undesired conditions
• • 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
  • 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
  • F16C2326/00—Articles relating to transporting
  • F16C2326/20—Land vehicles
• • 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
  • F16C2380/00—Electrical apparatus
  • F16C2380/26—Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators

Definitions

• the invention relates to an instrumented bearing intended to guide a mobile unit in rotation relative to a support, the mobile unit to be electrically connected to the support.
• Electric / hybrid vehicle engines are subject to failures due to current flow in the rolling bearings which equip them. These leakage currents can also affect the measurements or cause failures in the sensors with which these bearings may be fitted.
• Document DE 199 10 130 A1 describes a pulse measuring device intended to be fixed on a rotating shaft in order to determine its speed of revolution, which incorporates an electrical connection for returning leakage currents.
• This pulse sensor comprises a fixed outer ring, forming an annular guide track, an inner ring forming an annular guide track located opposite the guide track of the outer ring, the inner ring being movable relative to the ring outside around an axis of revolution which is an axis of symmetry of revolution of the guide track of the outer ring and of the guide track of the inner ring, an annular encoder secured to the inner ring, a sensor assembly secured to the outer ring, the sensor assembly comprising a read head positioned opposite and at a reading distance from the annular encoder, and a leakage current collector, capable of coming into sliding contact with a contact annular connected indirectly with the inner ring.
• such a device has a large axial bulk, and does not allow protection of the sensor against surrounding electromagnetic disturbances.
• the invention aims to remedy the drawbacks of the state of the art and to provide an instrumented bearing with integrated leakage current feedback, which is less sensitive to electromagnetic disturbances, such as may be encountered, in particular, in the environment of electric motors for propelling electric or hybrid road vehicles.
• an instrumented bearing comprising: a fixed outer ring, forming at least one annular guide track, an inner ring forming at least one annular guide track located facing the guide track of the outer ring, the inner ring being movable in rotation relative to the outer ring about an axis of revolution which is an axis of symmetry of revolution of the guide track of the outer ring and the inner ring guide track, an annular encoder secured to the inner ring, a sensor assembly secured to the outer ring, the sensor assembly comprising a read head positioned opposite and at a reading distance from the encoder, and a leakage current collector, capable of coming in sliding contact with an annular contact capable of being secured directly or indirectly with the inner ring, and a conductive electrical connection between the leakage current collector and the fixed outer ring.
• the encoder and the read head are positioned axially between the outer ring and the leakage current collector, and the conductive electrical connection constitutes a magnetic shielding made of a ferromagnetic material, extending from the ring external to the leakage current collector by surrounding the encoder and the read head.
• the bearing may be a plain bearing, or, preferably, a rolling bearing, comprising rolling bodies circulating on the guide tracks.
• the encoder can include one or more multipolar tracks. It is preferably a magnetic encoder. Such an encoder comprises one or more tracks, each consisting of an alternation of north and south magnetic poles, which may or may not be regular. Alternatively, the encoder can be a tone wheel.
• the read head comprises one or more elements sensitive to magnetic field variations produced by the encoder.
• the read head can face the encoder in the axial direction, in which case the encoder is preferably located between the read head and the inner ring of the bearing. Alternatively, the read head may face the encoder in a radial direction, in which case the read head is preferably located radially outside the encoder.
• the leakage current collector comprises a brush rubbing against the annular contact. It can be the graphite or carbon fiber brush, for maximum longevity.
• the leakage current collector is in contact with the annular contact on an angular sector greater than 270 °.
• the leakage current collector is in annular contact with the annular contact. The leakage current collector thus contributes to the high-frequency electromagnetic shielding of the read head.
• the annular contact is formed by an annular sleeve which has one or more of the following characteristics: the sleeve extends in the axial direction so as to be axially overlapping with a face of the encoder which faces at the read head; the sleeve extends axially so as to overlap axially with the read head; - the sleeve bears directly or indirectly against the inner ring; the socket is electrically connected to the inner ring; the socket is electrically connected to the shaft; the socket has a cylindrical friction surface for the leakage current collector; - The sleeve has a collar projecting radially outwards, the leakage current collector being positioned axially between the collar and the read head. The collar contributes to guiding the lines of the magnetic field by reducing the distance between the magnetic shielding and the rotating assembly guided by the bearing.
• the sleeve can advantageously be made of a ferromagnetic material such as soft iron, steel, in particular a ferritic or martensitic stainless steel, or of mu-metal.
• the magnetic shielding comprises at least one sheet of ferromagnetic material and an electrical conductor; the magnetic shielding comprises several superimposed sheets of ferromagnetic and electrically conductive material; the magnetic shielding comprises a cylindrical portion covering the read head; the magnetic shield has an end portion extending radially from one end of the cylindrical portion covering the read head radially inward and toward the leakage current collector.
• the magnetic shielding is reinforced by stacking the sheets so as to constitute a strip.
• part of the leakage current collector is clamped between two sheets of the magnetic shielding.
• a first of the two sheets extends axially to constitute a cylindrical portion covering the read head
• the second of the two sheets preferably having one of the following characteristics: the second of the two sheets does not extend axially to constitute a portion cylindrical covering the read head; the second of the two sheets extends axially to constitute a cylindrical portion covering the read head; the second of the two sheets is positioned between the first of the two sheets and the read head; - the first of the two sheets is positioned between the second of the two sheets and the read head.
• the magnetic shielding is provided is crimped, hooped, glued, welded to the outer ring.
• the sensor assembly is secured to the outer ring by means of the magnetic shielding.
• the magnetic shield has an opening for the passage of electrical conductors between the read head and an electrical device of the sensor assembly, positioned outside the magnetic shield, one of the characteristics
• the opening is positioned in a cylindrical wall of the magnetic shielding; the opening is positioned in a transverse wall of the magnetic shielding.
• FIG. 1 an instrumented bearing according to a first embodiment of the invention
• FIG. 2 a detail of an instrumented bearing according to a second embodiment of the invention
• FIG. 3 a detail of an instrumented bearing according to a third embodiment of the invention
• FIG. 4 a detail of an instrumented bearing according to a fourth embodiment of the invention
• FIG. 5 a detail of an instrumented bearing according to a fifth embodiment of the invention
• FIG. 6 a detail of an instrumented bearing according to a sixth embodiment of the invention.
• FIG. 1 is illustrated an instrumented bearing 10 mounted on a shaft 12 rotating relative to a fixed structure 14.
• the bearing 10 is a rolling bearing, comprising a fixed outer ring 16, forming an annular guide track 18 , an inner ring 20 forming an annular guide track 22 located opposite the guide track 18 of the outer ring 16, rolling bodies 24 circulating on the guide tracks 18, 22, where appropriate a cage 26 for retaining the rolling bodies, and where appropriate sealing gaskets 28 to protect the rolling bodies 24 and the guide tracks 18, 22 from external mechanical or chemical attacks, or else to confine the lubrication in the rolling zone, or to ensure these two functions simultaneously.
• the inner ring 20, shrunk onto the shaft 12 is movable in rotation relative to the outer ring 16 about an axis of revolution 100 which is an axis of symmetry of revolution of the guide track 18 of the outer ring 16 and the guide track 22 of the inner ring 20.
• An annular encoder 30 is secured to the inner ring 20 by any suitable means, for example by means of a crimped encoder holder 32 or shrunk on an inner perimeter of the inner ring 20.
• a sensor assembly 34 is secured to the outer ring 16.
• This sensor assembly 34 comprises a read head 36 positioned axially facing and at a reading distance from the annular encoder 30, a sensor body 38 made of insulating and non-magnetic material which supports an electrical device 40 which may for example be an electrical connector, an electrical cable, a cable gland or, where appropriate, an electronic signal processing card, and a wired electrical connection 42 between the read head 36 and the device electrical 40.
• the encoder 30 is located between the rings 16, 20 of the bearing 10 and the read head 36.
• the instrumented bearing 10 also comprises a leakage current collector 44 integral with the sensor assembly 34, and here consisting of an annular brush completely surrounding the shaft 12 and coming into sliding contact radially against a cylindrical friction surface 46 of an annular metal sleeve 48 directly shrunk onto the shaft 12.
• the encoder 30 and the read head 36 are positioned axially between the outer ring 16 and the leakage current collector 44.
• the sleeve 48 extends in the axial direction under the read head 36, and where appropriate under the encoder 30, so as to be axially overlapping with at least the read head 36, and of preferably with a face of the encoder 30 which faces the read head 36.
• the encoder holder 32 is clamped between the sleeve 48 and the inner ring 20.
• the assembly is stopped axially by a shoulder 50 of the shaft 12 and by an elastic ring 52.
• the encoder holder is made of a ferromagnetic material so in forming an electrical connection between the inner ring of the bearing and the sleeve, and in guiding the field lines around the encoder 30 ,.
• a conductive electrical connection 54 between the leakage current collector 44 and the outer ring 16 of the bearing 10 consists of an annular sheet of electrically conductive material, which extends from the outer ring 16 to leakage current collector 44 by surrounding the encoder 30 and the read head 36. An electrical path is thus established between the shaft 12 and the conductive electrical connection 54, which runs through the sleeve 48 shrunk onto the shaft 12 and the current collector leak 44 bypassing the inner ring 20 and outer ring 16 of the bearing 10, as well as the guide tracks 18, 22 and the rolling bodies 24.
• this electrical connection comprises a cylindrical portion 56 covering the read head 36 and a planar annular portion 58 extending from one end of the cylindrical portion 56 radially inward and towards the leakage current collector 44.
• the mechanical fixing of the electrical connection 54 to the outer ring 16 can be obtained in particular by crimping, shrinking, or any other means preserving electrical contact, for example by gluing or welding, or by fixing elements.
• a small opening 60 is formed in the cylindrical portion 56 for the passage of the electrical conductors 42 between the read head 36 and the electrical device 40.
• the sensor body of insulating material 38 of the sensor assembly 34 is molded onto the sheet 54 which thus has a mechanical function of supporting the sensor assembly 34 and of securing the assembly sensor 34 to the outer ring 16, thus, where appropriate, an angular indexing function of the sensor relative to the fixed structure 14.
• the leakage current collector 44 is clamped between a wall of the sheet 54 and the head reading 36.
• the electrical connection 54 between the leakage current collector 44 and the outer ring 16 is made of a ferromagnetic material, so as to constitute a magnetic shielding around the read head 36 and the encoder 30.
• ferromagnetic materials such as soft iron, steel, in particular ferritic or martensitic steel, or mu-metal.
• the material constituting the outer ring 16, the main function of which naturally remains the guiding of the rolling bodies 24, is also ferromagnetic, so as to participate in the guiding of the magnetic field lines around the read head 36, which will make prefer for this part a steel having the mechanical characteristics required by the application, in particular at the level of the raceways.
• the opening 60 for passage of the conductors 42 connecting the read head 36 to the electrical device 40 is formed in the flat end wall 58 of the conductive electrical connection 54.
• the conductive electrical connection 54 is constituted by a plurality of sheets, here by two sheets 54A, 54B, which both have a cylindrical part surrounding the read head and / or the encoder to improve the performance of the magnetic shielding, and an end part for fixing the leakage current collector.
• the leakage current collector 44 is clamped between the two sheets 54A, 54B.
• the two sheets 54A, 54B can be mounted tight, or glued.
• the end portion 58 of the conductive electrical connection 54 comprises two sheets 58A, 58B, for example welded to one another, serving to clamp the leakage current collector 44.
• the leakage current collector 44 is clamped between the sheet 54 and an insert 58C, which may be a metal part welded to the end portion 58 of the sheet 54 or an insulating washer. This embodiment appears particularly simple on assembly, the leakage current collector 44 being mounted from the outside of the sheet 54.
• the sleeve 48 comprises a collar.
• the leakage current collector 44 being positioned axially between the collar 62 and the read head 36.
• the magnetic shielding is thus improved by guiding the magnetic field lines up to 'to the shaft 12.
• the protection of the leakage current collector 44 against external pollution (dust, oil, water) is also improved.
• the invention is applicable to any type of rolling bearing or plain bearing.
• the contact surface 46 of the socket 48 with the leakage current collector 44 can be oriented in various ways, for example perpendicular to the axis of revolution or conical.
• the contact surface 46 can optionally be integrated into the shaft 12.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Rolling Contact Bearings (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Motor Or Generator Frames (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=70614076

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (6)

Family Cites Families (6)

• 2020
  • 2020-01-30 FR FR2000940A patent/FR3106869B1/fr not_active Expired - Fee Related
• 2021
  • 2021-01-29 WO PCT/EP2021/052095 patent/WO2021152082A1/fr not_active Ceased
  • 2021-01-29 JP JP2022546386A patent/JP7753228B2/ja active Active
  • 2021-01-29 CN CN202180007407.5A patent/CN114829793A/zh active Pending
  • 2021-01-29 EP EP21701801.9A patent/EP3931456B1/fr active Active
  • 2021-01-29 US US17/796,104 patent/US12152637B2/en active Active

Patent Citations (6)

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