Self-Aligning Roller Bearing with Retainer and Manufacturing Method for Self-Aligning Roller Bearing Retainer

A self-aligning roller bearing with retainer comprising:

• an outer ring formed with a spherically concave surfaced outer raceway on an inner peripheral surface thereof;
• an inner ring formed with a pair of inner raceways so as to oppose the outer raceway on an outer peripheral surface thereof, a plurality of spherical rollers provided so as to be freely rotatable in two rows between the outer raceway and the inner raceways, and a retainer having a plurality of pockets for holding the respective spherical rollers so that they may rotate freely,
• wherein the retainer is manufactured integrally by carrying out turning or grinding processing on a material of a copper based alloy or an iron based alloy and provided with an annular rim section disposed between the both rows of spherical rollers, and a plurality of column sections disposed in the axial direction of the outer ring and inner ring with their base end sections joined to a plurality of positions around the circumferential direction of the side surface in the axial direction of the rim section, and their respective end sections not joined to another section, being free ends, and portions between the column sections that are co-adjacent to each other in the circumferential direction are made the pockets,
• wherein a length of the column sections is greater than a half of the length in the axial direction of the spherical rollers,
• an end portion of the side surface in the circumferential direction of the respective column sections projects further in the circumferential direction than an intermediate portion thereof, and
• a distance between the side surfaces in the circumferential direction of the end sections of the column sections that are co-adjacent to each other in the circumferential direction is smaller than a maximum diameter of the spherical rollers.

A self-aligning roller bearing with retainer comprising:

• an outer ring formed with a spherically concave surfaced outer raceway on an inner peripheral surface thereof;
• an inner ring formed with a pair of inner raceways so as to oppose the outer raceway on an outer peripheral surface thereof, a plurality of spherical rollers provided so as to be freely rotatable in two rows between the outer raceway and the inner raceways, and a retainer having a plurality of pockets for holding the respective spherical rollers so that they may rotate freely,
• wherein the retainer is manufactured integrally by carrying out cutting or grinding processing on a material of a copper based alloy or an iron based alloy and provided with an annular rim section disposed between the both rows of spherical rollers, and a plurality of column sections disposed in the axial direction of the spherical rollers with their base end sections joined to a plurality of positions around the circumferential direction of the side surface in the axial direction of the rim section, and end sections not joined to another section, being free ends, and portions between the column sections that are co-adjacent to each other in the circumferential direction are made the pockets,
• wherein surfaces on both sides in the circumferential direction of the respective column sections are concave curved surfaces that oppose a rolling surface of the spherical rollers across a pocket clearance into which lubricant oil can be fed, and in the case where a sectional shape of the concave curved surface is expressed in terms of the axial direction and the radial direction of the retainer, a radius of curvature of the sectional shape in the axial direction is greater than or equal to the radius of curvature of the rolling surface of the spherical rollers in the axial direction, and the radius of curvature of the sectional shape in the radial direction is greater than the radius of curvature of the rolling surface about the circumferential direction by just the size of the pocket clearance, and
• wherein the surfaces on both sides in the circumferential direction of the column sections and the surface on one side in the axial direction of the rim section are made continuous at a corner section of each pocket, via undercut concave sections which respectively consist of a concave curved surface having a sectional arc shape of a radius of curvature greater than or equal to 1 mm.

A self-aligning roller bearing with retainer comprising:

• an outer ring formed with a spherically concave surfaced outer raceway on an inner peripheral surface thereof;
• an inner ring formed with a pair of inner raceways so as to oppose the outer raceway on an outer peripheral surface thereof, a plurality of spherical rollers provided so as to be freely rotatable in two rows between the outer raceway and the inner raceways, and a retainer having column sections at a plurality of positions around the circumferential direction, and having a plurality of pockets for holding the respective spherical rollers between the column sections that are co-adjacent to each other in the circumferential direction such that they can rotate freely, and the position of the retainer in the radial direction is controlled by engagement of the inside surface of the pockets with the spherical rollers,
• wherein, in a state where a central axis of the retainer is matched to a central axis of the self-aligning roller bearing with retainer,
• in a case where the spherical rollers are positioned in the middle in the circumferential direction between the column sections that are co-adjacent to each other in the circumferential direction,
• if a shortest distance in the radial direction of the retainer between the rolling surface of the spherical rollers and the side surfaces in the circumferential direction of the column sections is taken as H1, and
• in a case where the respective spherical rollers are maximally distant from the surface that opposes the end surfaces of the respective spherical rollers among the inside surfaces of the pockets,
• and if a shortest distance in the radial direction of the retainer from the opposing surfaces to the end surface is taken as H2,
• then H1≧H2 is satisfied.

A method of manufacturing a retainer that is to be assembled into the self-aligning roller bearing according to claim 2, comprising the acts of:

• inserting between plain column sections that are co-adjacent to each other in the circumferential direction, of a plurality of plain column sections, the respective base end sections of which are connected to an annular rim section at a plurality of places around the circumferential direction of the side surface in the axial direction of the rim section, and the respective end sections of which are made to be free ends that are not connected to any other sections, with spaces between both side faces in the circumferential direction being made smaller than the outer diameter of the spherical rollers, a turning tool having a convex curved outer peripheral surface, and for which, in the sectional shapes of the convex curved surface, the radius of curvature of the sectional shape about the axial direction is greater than or equal to the radius of curvature of the rolling surface of the spherical rollers about the axial direction, and the radius of curvature of the sectional shape about the circumferential direction is smaller than the radius of curvature of the rolling surface about the circumferential direction;
• and
• rotating the turning tool as it revolves around the central axis of the portion that is to become the pocket, and thus turning the surfaces on both sides in the circumferential direction of the plain column sections.