Patent ID: 11959513
Assignee: NTN CORPORATION
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A fluid dynamic bearing device, comprising:
a shaft member;
a bearing member having the shaft member inserted along an inner periphery of the bearing member; and
a radial dynamic pressure generating portion configured to support the shaft member in a relatively rotatable and non-contact manner with pressure of a fluid film formed in a radial bearing gap defined between an outer peripheral surface of the shaft member and an inner peripheral surface of the bearing member,
wherein the radial dynamic pressure generating portion comprises:
a plurality of polygonal hill portions pattern-arranged on any one of the inner peripheral surface of the bearing member and the outer peripheral surface of the shaft member;
a same number of polygonal groove portions as the polygonal hill portions, each of the polygonal groove portions formed in such a manner as to surround the polygonal hill portions; and
connection groove portions each configured to connect adjacent polygonal groove portions, and

wherein a sectional area of one of the connection groove portions is set to be larger than a sectional area of one of the polygonal groove portions.