Nsk Corporation

Hiroyuki Uchida

Yasuo Murakami

Dai Kinno

Tsuyoshi Saito

Koichi Hachiya

Hideyuki Hidaka

Shinji Fujita

Tomohiro Motoda

Tooru Shouda

Sadayuki Tanaka

Masateru Kondo

Akitoshi Maeda

Takamasa Ohira

Shingo Higashi

Naohiro Yoshida

Sho Hashimoto

Tomoki Doshida

Seisuke Takeda

Kazunobu Taketa

Haruo Kamijo

Daiju Takahashi

There is provided a method for evaluating the cleanliness of a steel material by an ultrasonic flaw detection method enabling rapid acquisition of highly reliable data. Ultrasonic flaw detection is performed to detect a flaw in at least one part in the range of 90% or more and 100% or less of a steel material (for example, round bar) at a radial position where the center of the steel material is set as 0% and the surface is set as 100%, and then the cleanliness is evaluated based on the dimension and the number of inclusions in the steel material obtained by the ultrasonic flaw detection.

Method for evaluating cleanliness of steel material

A rolling device in which rust development or damage on a raceway surface or rolling surface is hard to occur even if water and the like intrude is provided. A self-aligning roller bearing comprises an inner ring, an outer ring, and a plurality of rolling elementsdisposed rotatably between a raceway surfaceof the inner ringand a raceway surfaceof the outer ring. At least any one of the inner ring, the outer ring, and the rolling elementsis provided with a metal coating formed by shot peening of a powder of metal less noble than iron at least on a part of its surface.

Rolling device

A rolling device in which damage such as seizure or wear is less liable to occur and which has a long life, even when used under severe conditions such as high speed, heavy load, high temperature and insufficient lubrication. A thrust needle roller bearing includes an inner ring, outer ring, and a plurality of rolling elementsrollably arranged between a raceway surfaceof inner ringand a raceway surfaceof outer ring. A lubricant film consisting of a solid lubricant is coated over an area equivalent to an area ratio of 75% or more of at least one member of the group consisting of raceway surfaceof inner ring, raceway surfaceof outer ring, and a rolling contact surfaceof rolling element. The thickness of the lubricant film is preferably 0.05 &#x3bc;m or more and 8 &#x3bc;m or less.

Growing community of inventors

Fujisawa, Japan

Hiroyuki Uchida