Spindle motor and rotating shaft supporting device for spindle motor
AssigneeNtn Corporation
InventorsNatsuhiko Mori, Kazuo Okamura, Yasuhiro Yamamoto
Life of this patent
Estimating the term…
Abstract
Bearing 1 comprises a porous bearing body 1a having a bearing surface 1b disposed to oppose an outer circumferential surface of the rotating shaft 3 via a bearing clearance 4, a lubricating oil or lubricating grease impregnated in the bearing body 1a, and hydrodynamic pressure generating grooves 1c formed on the bearing surface 1b of the bearing body 1a. The rotating shaft 3 is supported, without making contact with the bearing 1, by a hydrodynamic pressure oil film formed in the bearing clearance and the oil is circulated, via openings made in the surface of the bearing body 1a, between the inside of the bearing body 1a and the bearing clearance 4.
Claims23
A supporting device for a spindle motor of information equipment, comprising a rotating shaft driven and rotated by an excitation force produced between a rotor and a stator, on which rotating elements of information equipment are attached, and a bearing for rotatably supporting the rotating shaft;
- wherein said bearing comprises a porous bearing body having a bearing surface disposed to oppose an outer circumferential surface of the rotating shaft via a bearing clearance, a lubricating oil or lubricating grease is impregnated in the bearing body, and hydrodynamic pressure generating grooves are formed on the bearing surface of the bearing body in such a configuration as to be inclined with respect to the axial direction, so that the rotating shaft is supported, without making contact with the bearing, by a hydrodynamic pressure oil film formed in the bearing clearance and the oil is circulated, via openings made in the surface of the bearing body, between the inside of the bearing body and the bearing clearance, wherein
- the ratio of bearing clearance c to groove depth h of the hydrodynamic pressure generating grooves is within a range of:
- c/h=0.5 through 4.0.
A spindle motor for optical disk unit having a rotating shaft with a turn table mounted thereon for supporting an optical disk, a bearing which supports the rotating shaft, a rotor mounted on the rotating shaft or on a rotary member which rotates along with the rotating shaft, and a stator mounted on a stationary member, wherein
- a diameter of said rotating shaft is 3 mm or less;
- and
- said bearing comprises a bearing body made of a porous sintered metal having a bearing surface disposed to oppose an outer circumferential surface of the rotating shaft via a bearing clearance, a lubricating oil or lubricating grease is impregnated in the bearing body and hydrodynamic pressure generating grooves are formed on the bearing surface of the bearing body in such a configuration as to be inclined with respect to the axial direction, so that the rotating shaft is supported, without making contact with the bearing, by a hydrodynamic pressure oil film formed in the bearing clearance and the oil is circulated, via openings made in the surface of the bearing body, between the inside of the bearing body the bearing clearance, wherein
- a ratio of bearing clearance c to groove depth h of the hydrodynamic pressure generating grooves is within a range of:
- c/h=0.5 through 2.0.
A rotating shaft supporting device for a spindle motor of optical disk unit having a rotating shaft, which has a turn table mounted thereon for supporting an optical disk and is driven to rotate by an excitation force generated between a rotor and a stator, and a bearing which supports the rotating shaft to be rotatable, wherein
- a diameter of said rotating shaft is 3 mm or less;
- and
- said bearing comprises a bearing body made of a porous sintered metal having a bearing surface opposed to the outer circumferential surface of the rotating shaft via a bearing clearance, a lubricating oil or lubricating grease is impregnated in the bearing body and hydrodynamic pressure generating grooves are formed in the bearing surface of the bearing body in such a configuration as to be inclined with respect to the axial direction, so that the rotating shaft is supported, without making contact with the bearing, by a hydrodynamic pressure oil film formed in the bearing clearance and the oil is circulated, via openings made in the surface of the bearing body, between the inside of the bearing body and the bearing clearance, wherein
- a ratio of bearing clearance c to groove depth h of the hydrodynamic pressure generating grooves is within a range of:
- c/h=0.5 through 2.0.
Dependencies are inferred from the claim text.