| 摘要 |
PROBLEM TO BE SOLVED: To provide a radial needle roller bearing and a bearing unit, which improve durability by suppressing a damage on a cage and also improve assemblability. SOLUTION: In a radial needle roller bearing, a cage 12 keeps between adjacent column parts a projection 12e axially projecting from an outer peripheral edge of an annular part 12a and allowing a corner R part 11a of a roller 11 to abut thereon. A relational expression of PRy<r/cosβ+(hp/sinβ-PRx)×tanβ is satisfied, wherein an axial distance and radial distance between an abutting point P of an inside diameter side part abutting on the roller 11 and a corner part the projection 12e abutting on a corner R part 11a of the roller 11 are taken as PRx and PRy, respectively, a distance between the center line O of the roller 11 and the abutting point as hp, and a radius of the roller 11 as r when a roller 11 is tilted by β° in a radial direction, or a relational expression of MNx>MRx is satisfied, wherein an axial distance of the corner R part 11a of the roller 11 taken as MNx and an axial width of the projection 12e as MRx when the roller 11 is tilted by β° in a radial direction. COPYRIGHT: (C)2011,JPO&INPIT
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