Patent ID: 9154012
Filing Date: 2015-10-06
Classification: F16C,H02K

Abstract:
1. A fluid dynamic bearing device, comprising: an outer member having a radial bearing surface and thrust bearing surfaces respectively formed on both axial sides of the radial bearing surface; and an inner member arranged on an inner diameter side with respect to the outer member and having a radial bearing surface and thrust bearing surfaces respectively facing the radial bearing surface of the outer member and the thrust bearing surfaces of the outer member, the inner member is supported in a freely rotatable manner with respect to the outer member, the radial bearing surface of the outer member and the radial bearing surface of the inner member forming a radial bearing gap therebetween, one of the thrust bearing surfaces of the outer member and one of the thrust bearing surfaces of the inner member forming one thrust bearing gap therebetween, another of the thrust bearing surfaces of the outer member and another of the thrust bearing surfaces of the inner member forming another thrust bearing gap therebetween, the radial bearing gap and the thrust bearing gaps having a lubricating oil interposed therein, wherein the outer member comprises a member formed by a pressing process on a plate member, the radial bearing surface and at least the one of the thrust bearing surfaces of the outer member being formed by the pressing process, and wherein at least a part of the inner member, which forms the radial bearing surface and the thrust bearing surfaces of the inner member, is made of a sintered metal, wherein the outer member comprises a first outer portion and a second outer portion, wherein each of the first outer portion and the second outer portion is composed of the plate member having a substantially L-shape in vertical cross-section and each comprises a cylindrical portion and a radial portion provided at one end of the cylindrical portion, wherein an axial length of the cylindrical portion of the first outer portion is substantially the same as an axial length of the cylindrical portion of the second outer portion, wherein the one of the thrust bearing surfaces is formed on an inside surface of the radial portion of the first outer portion, wherein the radial bearing surface is formed on an inner peripheral surface of the cylindrical portion of the second outer portion, wherein the another of the thrust bearing surfaces is formed on an inside surface of the radial portion of the second outer portion, and wherein an outer peripheral surface of the cylindrical portion of the second outer portion is fitted and fixed to an inner peripheral surface of the cylindrical portion of the first outer portion.