Self-aligning roller bearing

Patent metadata

Field	Value
Publication number	US-2022010836-A1
Application number	US-202117486011-A
Country	US
Kind code	A1
Filing date	Sep 27, 2021
Priority date	Apr 5, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

Provided is a self-aligning roller bearing for supporting a main shaft of a wind power generator, the self-aligning roller bearing including an inner ring, an outer ring, two rows of rollers, and retainers. Each of the rollers has an outer peripheral surface formed with a DLC coating having a multilayer structure. The DLC coating has a film thickness of 2.0 μm or larger. A base material of each of the rollers has an external surface having a surface roughness of Ra≤0.3 and RΔq≤0.05. The DLC coating having the multilayer structure includes layers having stepwisely increasing film hardnesses such that a layer situated closer to outside has a higher hardness.

First claim

What is claimed is:

1 . A self-aligning roller bearing configured to support a main shaft of a wind power generator, the self-aligning roller bearing comprising:
an inner ring; an outer ring; two rows of rollers interposed between a raceway surface of the inner ring and a raceway surface of the outer ring; and a retainer configured to retain the respective rows of the rollers, wherein the raceway surface of the outer ring has a spherical shape continuously extending over the two rows of the rollers, each of the rollers having an outer peripheral surface having a cross-sectional shape matching the raceway surface of the outer ring, each of the rollers has a DLC coating having a multilayer structure on the outer peripheral surface, the DLC coating has a film thickness of 2.0 μm or larger, a base material of each of the rollers has an external surface having a surface roughness of Ra≤0.3 and RΔq≤0.05, and the DLC coating having the multilayer structure includes layers having stepwisely increasing film hardnesses such that a layer situated closer to outside has a higher hardness.

2 . The self-aligning roller bearing as claimed in claim 1 , wherein the retainer includes an annular portion and a plurality of pillar portions axially extending from the annular portion at a plurality of locations in a circumferential direction of the annular portion such that the retainer is formed in a comb shape,
the pillar portions have pocket surfaces which are formed as cylindrical surfaces and define pockets, a center of each of the cylindrical surfaces being inclined with respect to the pillar portions such that distal ends of the pillar portions approach a center of the retainer, and each of the pillar portions is formed with a tapered portion on an outer diametric surface of a distal end of that pillar portion, the tapered portion approaching an inner diametric side of the retainer as the tapered portion extends to a most distal end of that pillar portion.

3 . The self-aligning roller bearing as claimed in claim 2 , wherein the retainer has, with respect to a pitch circle diameter PCD of an arrangement of the rollers,
an outer diameter in a range of PCD×102% to PCD×105%, and an inner diameter in a range of PCD×95% to PCD×98%, and parts of the pillar portions which define the pockets have a length equal to or shorter than 65% of a roller length.

4 . The self-aligning roller bearing as claimed in claim 2 , wherein the tapered portion of each of the pillar portions of the retainer extends from a position at a maximum diameter angle which is an angle of the retainer at a position where the rollers have a maximum diameter or from a position closer to the distal end of that pillar portion with respect to the position at the maximum diameter angle.

5 . The self-aligning roller bearing as claimed in claim 2 , wherein each of the pillar portions has a smallest pillar portion width at the most distal end of that pillar portion when viewed from the outside in the radial direction of the retainer toward the center side of the retainer.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Seko Kazumasa
• Nakanishi Masaki
• Yamamoto Takashi

Classifications

• F16C2240/60

  Thickness, e.g. thickness of coatings · CPC title

• F16C2240/54

  Surface roughness · CPC title

• F16C2223/30

  Coating surfaces · CPC title

• F16C2206/04

  Diamond like carbon [DLC] · CPC title

• F16C23/086

  forming a track for rolling elements · CPC title