Okuma Non-round Plain Bearing and GPB Cylindrical Grinder

The Okuma non-round plain bearing is a dynamic pressure bearing developed by Shinkichi Nagaoka in 1954. The wedge-shaped oil film is formed as the main shaft rotates at three points on the periphery of the bearing, thereby achieving high rotation precision and rigidity.

The GPB cylindrical grinder is a revolutionary grinding machine. The non-round plain bearing is mounted and the rough cutting, finishing and sizing processes are performed in a consecutive cycle, thereby achieving a mirror finish.

The technology, since succeeded by the present-day CNC cylindrical grinder, constitutes the best-known revolutionary technique of machine tools and served as the foundation for growth of the precision machinery industry in Japan after World War II.