Ntn Corporation

Yasutake Hayakawa

Katsutoshi Muramatsu

Eiichirou Shimazu

Mitsuo Kawamura

Eiichiro Shimazu

Takahiro Okuno

Ryuichi Sakamoto

Junichi Ooshimo

A green ball grinding method includes the step of supplying a green ball between a first surface of a first member and a second surface of a second member constituting a grinding apparatus, and the step of grinding the green ball between the first surface and the second surface while the green ball rotates around its own axis and in orbital motion. In the step of grinding the green ball, the step of causing the green ball grinding to proceed while applying load between the green ball and each of the first surface and the second surface, and the step of modifying the rotation axis of the green ball by reducing the load lower than in the step of causing the green ball grinding to proceed are executed alternately.

Green ball grinding method, ceramic sphere fabrication method, and grinding apparatus

A cage is made of a magnesium alloy such as AZ91D, and is molded by means of injection molding. In this cage, a confluence region is brought away to outside the cage during the injection molding. The confluence region is a region including a void formed by merging of flows of the magnesium alloy. When observing a cross sectional surface of the cage, a ratio of an &#x3b1; phase having a grain size of 20 &#x3bc;m or greater is less than 15% in the magnesium alloy constituting the cage.

Cage and rolling bearing

A cage () is made of a magnesium alloy and has a light weight and a high strength. The cage () is made of a magnesium alloy such as AZ91D, and is formed by means of injection molding. In this cage (), a confluence region is brought away to outside the cage () during the injection molding. The confluence region is a region including voids formed by merging of flows of the magnesium alloy.

Cage, rolling bearing, method for manufacturing cage, and injection mold

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Kuwana, Japan

Yasutake Hayakawa