By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Capoldi, Bruno (Charentenay, FR); Bredoire, Vincent (Pourrain, FR), filed on February 9, 2018, was made available online on August 16, 2018.



The patent's assignee is Aktiebolaget SKF (Goteborg, Sweden).



News editors obtained the following quote from the background information supplied by the inventors: "Particularly in the field of large-diameter bearings, for example large-diameter rolling bearings such as slewing bearings adapted to be used in wind turbines, tunnel boring machines, cranes, ladle turret, marine thrusters, stacker reclaimer, it is known to use segmented cages which comprise segments abutting circumferentially and having pockets for receiving the rolling elements. Each segment comprises a plurality of adjacent pockets, each pocket receiving one or several rolling elements.



"Currently, such a segment with pockets receiving each several rolling elements is metallic and made from typically from brass. Such a segment with pockets receiving each only one rolling element is metallic (brass) or made from synthetic material.



"Known segments are massive and heavy, in particular the ones made from metal.



"Known segments can be obtained by different several manufacturing processes, including molding, injection molding, sand molding or machining.



"Injection molding is the preferred manufacturing process for a segment made from synthetic material, but due to the large dimensions of the segment and its current geometry, it is not easy to inject synthetic material uniformly in the mold, and unfortunately sometimes bubbles of air are trapped in the segment, which degrades its mechanical properties. Also, still because of different geometrical thicknesses of portions of the segment, the shrinkage occurring during the cooling of the injected material is not uniform and lead to deformation of the segment or even sometimes its breakage.



"Such a difference of thickness is present in a known segment illustrated on FIG. 1. The segment comprises an inner wall and an outer wall extending circumferentially (not represented) and radial beams 27 which connect together the inner and outer walls. Each radial beam comprises a central portion 27a and two opposite end portions 27b, 27c. At least one end portion 27b, 27c cooperates with one rolling element 9 to center the segment onto the rolling elements. The end portions are wider than the central portion, which indeed constitutes a difference of thickness, in the circumferential direction, of the radial beam.



"The above situations induce scraps and untimely deteriorations and are not satisfying."



As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "According to one aspect of the invention, one embodiment, it is proposed a cage segment for a bearing rotatable around an axis X1 and able to receive a plurality of rolling elements meant to travel on two annular radial raceways of respectively an inner ring and an outer ring of the bearing.



"The cage segment comprises an inner wall and an outer wall which both extend circumferentially in the form of a portion of cylinder, the axis of symmetry of which being X1.



"The cage segment also comprises a plurality of radial beams which extend globally radially with respect to the axis and which connect the inner and outer walls.



"Each radial beam comprises, in the axial direction, a central portion and two end portions which are opposite with respect to the central portion, at least one of the two end portions cooperating with a rolling element in order to center the segment onto the rolling elements.



"The central portion and the end portions are each symmetrical with respect to a respective plane.



"The plane of symmetry of the at least one end portion which cooperates with a rolling element to center the segment forms with the plane of symmetry of the central portion an angle which is not equal to zero.



"According to further aspects of the invention which are advantageous but not compulsory, such a segment may incorporate one or several of the following features:



"The central portion of the radial beam extends axially and at least one of the end portions of the radial beam extends axially and circumferentially;



"Both end portions extend axially and circumferentially;



"The planes of symmetry of the end portions form with the plane of symmetry of the central portion the same angle;



"One end portion extends axially and the other end portion extends axially and circumferentially;



"In a direction perpendicular to their respective plane of symmetry, the central portion and each end portion each have a constant thickness;



"These thicknesses are identical;



"The segment is made of a synthetic material and obtained by injection molding.



"According to another aspect of the invention, a segmented cage for a bearing, comprises at least two successive segments according to the invention, each being able to receive at least one rolling element.



"According to another aspect of the invention, a rolling bearing comprises a plurality of rings, rolling elements interposed between the rings and, for receiving the rolling elements, at least one of the cage segment or segmented cage according to the invention."



The claims supplied by the inventors are:



"1. A cage segment for a bearing rotatable around an axis that defines an axial direction, the cage segment able to receive a plurality of rolling elements configured to travel on two annular radial raceways and of respectively an inner ring and an outer ring of the bearing, and comprising: an inner wall that extends circumferentially in the form of a portion of cylinder, the axis of symmetry of which being the axis (X1); an outer wall that extends circumferentially in the form of a portion of cylinder, the axis of symmetry of which being the axis (X1); a plurality of radial beams extending globally radially with respect to the axis (X1) and connecting the inner and outer walls, each radial beam comprising, axially, a central portion and two end portions, which are opposite with respect to the central portion, the central portion being symmetrical with respect to a plane (Pa), at least one of the two end portions cooperating with a rolling element in order to center the segment onto the rolling elements, wherein each end portion is symmetrical with respect to a plane (Pb, Pc), respectively, and the plane of symmetry (Pb, Pc) of the at least one end portion cooperating with a rolling element to center the segment in order to form with the plane of symmetry (Pa) of the central portion an angle (Ab, Ac) which is not equal to zero.



"2. The cage segment according to claim 1, wherein the central portion of the radial beam extends axially and at least one of the end portions of the radial beam extends axially and circumferentially.



"3. The cage segment according to claim 2, wherein both end portions extend axially and circumferentially.



"4. The cage segment according to claim 3, wherein the planes of symmetry of the end portions form with the plane (Pa) of symmetry of the central portion the same angle (Ab, Ac).



"5. The cage segment according to claim 2, wherein one end portion extends axially and the other end portion extends axially and circumferentially



"6. The cage segment according to claim 1, wherein a direction perpendicular to the plane (Pa), the central portion has a thickness, in a direction perpendicular to the plane (Pb), the corresponding end portion has a thickness (Tb), in a direction perpendicular to the plane (Pc), the corresponding end portion (27c) has a thickness (Tc), and in that the thicknesses (Ta), (Tb) and Tc) are constant.



"7. The cage segment according to claim 6, wherein the thicknesses are identical.



"8. The cage segment according to claim 1, further comprising being made of a synthetic material and obtained by injection molding.



"9. A segmented cage for a bearing comprising: a plurality of cage segments according to claim 1, wherein the cage segments are adjacent in a normal state of the assembled bearing.



"10. A bearing comprising: a plurality of rings, rolling elements interposed between the rings and, for receiving the rolling elements, at least one cage segment according to claim 1.



"11. A bearing comprising: a plurality of rings, rolling elements interposed between the rings and, for receiving the rolling elements, at least one cage segment according to claim 9."



For additional information on this patent application, see: Capoldi, Bruno; Bredoire, Vincent. Cage Segment, Segmented Cage, And Bearing. Filed February 9, 2018 and posted August 16, 2018. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220180231057%22.PGNR.&OS=DN/20180231057&RS=DN/20180231057



Keywords for this news article include: Europe, Sweden, Business, Goteborg, Aktiebolaget SKF.



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