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
  • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
  • F16C33/30—Parts of ball or roller bearings
  • F16C33/34—Rollers; Needles
  • F16C33/36—Rollers; Needles with bearing-surfaces other than cylindrical, e.g. tapered; with grooves in the bearing surfaces
  • F16C33/363—Rollers; Needles with bearing-surfaces other than cylindrical, e.g. tapered; with grooves in the bearing surfaces with grooves in the bearing-surfaces
• • 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
  • F16C23/00—Bearings for exclusively rotary movement adjustable for aligning or positioning
  • F16C23/06—Ball or roller bearings
  • F16C23/08—Ball or roller bearings self-adjusting
  • F16C23/082—Ball or roller bearings self-adjusting by means of at least one substantially spherical surface
  • F16C23/086—Ball or roller bearings self-adjusting by means of at least one substantially spherical surface forming a track for rolling elements
• • 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
  • F16C19/22—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings
  • F16C19/24—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for radial load mainly
  • F16C19/26—Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for radial load mainly with a single row of rollers
• • 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
  • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
  • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
• • 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
  • F16C2361/00—Apparatus or articles in engineering in general
  • F16C2361/61—Toothed gear systems, e.g. support of pinion shafts

Definitions

• the invention relates to a roller for a rolling bearing and a rolling bearing in which such rollers are mounted.
• the invention applies in particular to rollers for an epicyclic gear bearing, in particular a planet bearing of an epicyclic reduction gearbox for a helicopter gearbox.
• rollers in particular of spherical barrel geometry.
• Each roll has an outer surface of revolution about an axis of symmetry and a side face disposed on each side of said outer surface.
• These rollers are intended to be mounted in the bearing by being arranged in a retention cage so as to be able to rotate in said bearing around their axis of symmetry while bearing on their outer surface.
• the lateral faces of the rollers may have a recess in which an axial projection of the cage is engaged so as to keep each of said rollers rotating about their axis of symmetry.
• the satellite bearings according to the prior art have a significant weight, which is even more critical for an aeronautical application in which five to ten bearings are conventionally embedded in a planetary reducer equipping a gearbox.
• the object of the invention is to improve the prior art by notably proposing rollers for rolling bearings which have a reduced mass while satisfying the functional requirements of the bearing, in particular with respect to the structural fatigue of said rollers under the effect of the cycles of loads that they undergo in time.
• the invention proposes a roller for rolling bearing, said roller having an outer surface of revolution about an axis of symmetry and a lateral face disposed on each side of said outer surface, said roller being adapted to rotate in said bearing about its axis of symmetry while resting on its outer surface, said roller having two recesses which are respectively formed on a lateral face extending along the axis of symmetry, said recesses having an opening diameter di measured on the side face and being axially separated by a material bridge of length e, said opening diameter and said length of the material bridge fulfilling the following geometrical condition: 0.1 ⁇ - ⁇ 1. d ⁇
• the invention proposes a rolling bearing comprising an inner member and an outer member between which are mounted such rollers, said rollers being arranged in a retention cage so as to be rotatable about their axis of symmetry. being supported on said members via their outer surface.
• FIG. 1 shows in perspective cutaway a rolling bearing according to one embodiment of the invention
• Figures 2 show a roller according to one embodiment of the invention, respectively in longitudinal section ( Figures 2a and 2c) and a top view showing the contact ellipse ( Figure 2b).
• a rolling bearing in the form of an epicyclic reduction gearbox bearing for a helicopter gearbox is described below.
• the epicyclic gear is an effective mechanical principle for transmitting power and reducing speed in a small footprint.
• the mass of the bearings This mechanical assembly is important (bearings in large numbers: generally between five and ten).
• the bearing comprises an inner ring 1 and an outer ring 2.
• the outer surface of the outer ring 2 is provided with a gear means formed of axial teeth 3.
• a rolling bearing according to the invention may find application in another field in which in particular a weight gain of said bearing is desirable.
• the rings 1, 2 each comprise a raceway between which is arranged a row of rollers 4 so as to allow the relative rotation of said rings.
• rollers 4 which each have an outer surface 5 of revolution about an axis of symmetry A and a lateral face 6 disposed on each side of said outer surface, is described below.
• the rollers 4 may be made of metal material, especially rolled steel type 100Cr6.
• the rollers 4 are intended to rotate about their axis of symmetry A during the rotation of said bearing, said rollers bearing on the rolling tracks via their outer surface 5. Moreover, when the rotation, the side faces 6 are guided along a shoulder or the retention cage 7 so as to maintain the rollers 4 in the bearing.
• the outer surface 5 has a barrel spherical geometry of radius R (commonly called barrel roll) in which the diameter d of side faces 6 is smaller than the central diameter D of said outer surface.
• the lateral faces 6 extend respectively in a plane transverse to the axis of symmetry A, the diameters d being measured in the transverse planes and said planes being spaced from a length L corresponding to that of the roller 4.
• the roller 4 may have a cylindrical or conical geometry.
• the invention proposes a relief of the rollers 4 that it incorporates.
• the rollers 4 have two recesses 8 which are made, in particular by drilling, turning or milling, respectively on a lateral face 6 extending along the axis of symmetry A.
• the recesses 8 have an opening diameter di measured on the side face 6 and are separated axially by a material bridge 9 of length e.
• the rollers 4 are subjected to structural fatigue as a result of the load cycles they undergo over time.
• the invention proposes to reduce the amount of material of the rollers 4 in the less mechanically stressed areas and to keep it elsewhere.
• the opening diameter di and the length e of the material bridge 9 can fulfill the following geometrical condition: 0.1 ⁇ - ⁇ 1.
• the recesses 8 are d ⁇ arranged to maintain a sufficient wall thickness to mechanically withstand the stresses experienced during the rotation of the bearing.
• the length e of the material bridge 9 is determined according to the application to be sufficient to be certain, with the safety margins in force in said application, not to risk a fatigue failure of a roller 4 in the bearing.
• each recess 8 has a convergent frustoconical geometry having a bottom diameter d 2 on the junction zone with the diameter bridge 9, said bottom diameter being smaller than the opening diameter di .
• the maximum diameter D of the outer surface 5 is disposed in the center of said surface, around the material bridge 9.
• the contact zone (called Hertz) between a roller 4 and the rolling tracks is positioned at right of the center of the roll 4, that is to say the right of the material bridge 9, the Hertz stress depth being directly related to the level of contact pressure between the roller 4 and the tracks.
• the contact zone has an elliptical shape 10 (FIG. 2b) which has a large length L e .
• each recess 8 may have a diameter d e measured at a quarter of the great length L e of the contact ellipse 10 of which is such that e ⁇ D ⁇ •
• the thickness diametral Dd e of the material around the material bridge 9, that is to say the depth of material left in this area, is greater than W, so as to be sufficient to ensure the structural strength of the rollers 4 in fatigue.
• the junction zone between the recesses 8 and the material bridge 9 has a connection radius r, said connection radius r being in particular greater than 0.1 mm.
• the recesses 8 extend over a depth P defined between diameters di and d 2 , the connection radius r being formed from said bottom diameter d 2 .
• said rollers are arranged in a retention cage 7 so as to be rotatable about their axis of symmetry A while bearing on the members 1 , 2 through their outer surface 5.
• the cage 7 is formed in one piece, in particular by machining a metallic material, to comprise a first ring and, offset axially, a second ring, said rings having the same diameter.
• the cage further comprises a plurality of axial crosspieces which extend between said crowns so as to form between two adjacent crosspieces and the crowns a retention housing of a roller 4.
• the internal geometry of the housing is formed to fit the periphery of the roll 4 allowing its rotation about its axis of symmetry A.
• each lateral face of a roll 4 is disposed facing respectively a side face of a housing, a hooking means of said roller being formed on each side face of said housing.
• the hooking means comprises an axial projection engaged in a recess 8 of the roll 4 so as to keep said roll in said housing in rotation.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rolling Contact Bearings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41254602

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Family Cites Families (5)

• 2009
  • 2009-04-10 FR FR0901803A patent/FR2944330B1/fr not_active Expired - Fee Related
• 2010
  • 2010-04-06 WO PCT/FR2010/000291 patent/WO2010116058A1/fr active Application Filing
  • 2010-04-06 EP EP10717184A patent/EP2417371A1/de not_active Withdrawn

Non-Patent Citations (1)

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