Ntn Corporation

Hiroaki Suzuki

Katsutoshi Muramatsu

Daichi Ito

Yasuhito Fujikake

Yutaka Tanaka

Tomoya Nakamura

Masayuki Nozaki

An inspection method of a rolling element includes the steps of: projecting an X-ray from a light source to a rolling element, detecting the X-ray passing through the rolling element by a detector, calculating data of the detected X-ray to form an image, and detecting a defect in the rolling element based on the image. At the step of projecting an X-ray, the light source rotates relatively around the rolling element while the X-ray is projected to an entire region of the rolling element facing the light source. At the step of forming an image, data of the X-ray for one circuit around the rolling element is calculated to generate the image.

Rolling element inspection method, rolling element manufacturing method, and rolling element

Radial passages () that penetrate from the inner diameter side to the outer diameter side of a retainer () are provided between inner wall surface portions () of a pocket () facing each other in an axial direction of the retainer and a rolling element () so that the radial passages () serve as a grease reservoir as well as a grease passage for allowing the grease adhering to the rolling element () to move onto an outer ring raceway surface (). The radial passages () are made up of arc-shaped spaces () between the rolling element () and the inner wall surface portions () of the inner wall surface of a pocket () and segment shaped spaces () between the rolling element () and arcuate recesses () at the four corners of the pocket ().

Rolling bearing unit

Growing community of inventors

Kuwana, Japan

Hiroaki Suzuki