Fluid-dynamic bearing system for spindle motor of hard disk drive, has large diameter portion whose faces form radial bearing, where radial bearing and pumping seal are arranged along large diameter portion of shaft

摘要

The system has a fixed shaft (12) and a bearing bush (10) forming a bearing gap (14) between assigned bearing faces. The shaft comprises a portion (12a) with large diameter and a portion (12b) with minor diameter. The faces of the portion with large diameter and the bearing bush form a fluid-dynamic radial bearing (16). The faces of the portion with minor diameter form another fluid-dynamic radial bearing (18). The former radial bearing and a dynamic pumping seal are arranged along the portion with large diameter of the shaft. Independent claims are also included for the following: (1) a spindle motor (2) a hard disk drive.