Rotating device

Abstract

A rotating device includes a shaft body having a shaft, a first flange extending in the radial direction from the side face of the shaft, and a second flange extending outwardly of the radial direction from another end side, a freely rotatable bearing body including a shaft encircling member present between the second flange and the first flange in the axial direction, a radial dynamic pressure generating groove provided in either one of the shaft and the shaft encircling member, a first thrust dynamic pressure generating groove provided in either one of the first flange and the shaft encircling member, and a lubrication medium. An end of the region where the radial dynamic pressure generating groove is formed and which is distant from the second flange is located outwardly of the region where the first thrust dynamic pressure generating groove is disposed in the axial direction.

What is claimed is: 
     
         1 . A rotating device configured to rotate a recording disk to be mounted on a hub, the rotating device comprising:
 a shaft body comprising;
 a shaft; 
 a first flange extending outwardly in a radial direction from a side face of the shaft at a first end thereof; 
 a second flange extending outwardly in the radial direction from a side face of the shaft at a second end thereof; and 
 a flange encircling member which extends toward the first flange from an outer periphery of the second flange in an axial direction, and is joined together with the second flange; 
   a bearing body comprising:
 a shaft encircling member which is present in a space between the first flange and the second flange in the axial direction so as to encircle the shaft, is freely rotatable relative to the shaft, and is encircled by the flange encircling member with a clearance; and 
 a ring portion that encircles a part of the first flange; 
   a radial dynamic pressure generating groove provided in either one of an outer periphery of the shaft and an inner periphery of the shaft encircling member; and   a first thrust dynamic pressure generating groove provided in either one of a surface of the first flange and a surface of the shaft encircling member, which surfaces face with each other in the axial direction,   wherein:   a space that holds lubricant is formed between the shaft body and the bearing body;   the radial dynamic pressure generating groove includes a protruding section that protrudes in an opposite direction to the second flange in the axial direction from a surface where the first thrust dynamic pressure generating groove is formed;   the clearance between the flange encircling member and the shaft encircling member in the radial direction widens toward the first flange in the axial direction; and   the shaft includes a seat abutting with an end face of the first flange, the seat being provided at the first end side and above the protruding section in the axial direction.   
     
     
         2 . The rotating device according to  claim 1 , wherein:
 the hub includes a groove which is engageable with a disk clamper and is provided annularly in an outer periphery of the hub, the outer periphery of the hub being engageable with a center hole of the recording disk, and the clamper clamping the recording disk to the outer periphery of the hub; and   the protruding section is located inwardly in the radial direction relative to the groove.   
     
     
         3 . The rotating device according to  claim 1 , further comprising a disk clamper that fastens the recording disk to the hub,
 wherein the protruding section at least partially overlaps a portion of the disk clamper in the axial direction, with the disk clamper being fastened to the hub.   
     
     
         4 . The rotating device according to  claim 1 , further comprising:
 a disk clamper that fastens the recording disk to the hub; and   a coil covered by the hub and provided in an unrotatable manner,   wherein the coil is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         5 . The rotating device according to  claim 1 , further comprising:
 a disk clamper that fastens the recording disk to the hub; and   a magnet fixed to the hub,   wherein the magnet is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         6 . The rotating device according to  claim 1 , wherein:
 the shaft includes an overlap portion where an external piece formed with a hole in the axial direction, and an internal piece to be retained in the hole in the axial direction overlap in the axial direction;   the bearing body includes an inclined face formed in an outer periphery of the shaft encircling member;   the inclined face overlaps the overlap portion in the axial direction;   the inclined face has a larger inclination than an inclination of the flange encircling member; and   the inclined face is disposed outwardly in the radial direction and downwardly in the axial direction relative to the protruding section.   
     
     
         7 . The rotating device according to  claim 1 , further comprising a base that supports the shaft body in a fixed manner, wherein:
 the base comprises a base protrusion that encircles the flange encircling member; and   a protruding end of the base protrusion is located in the axial direction between the seat of the shaft and the flange encircling member.   
     
     
         8 . A rotating device configured to rotate a recording disk to be mounted on a hub, the rotating device comprising:
 a shaft body comprising;
 a shaft; 
 a first flange extending outwardly in a radial direction from a side face of the shaft at a first end thereof; 
 a second flange extending outwardly in the radial direction from a side face of the shaft at a second end thereof; and 
 a flange encircling member which extends toward the first flange from an outer periphery of the second flange in an axial direction, and is joined together with the second flange; 
   a bearing body comprising:
 a shaft encircling member which is present in a space between the first flange and the second flange in the axial direction so as to encircle the shaft, is freely rotatable relative to the shaft, and is encircled by the flange encircling member with a clearance; and 
 a ring portion that encircles a part of the first flange; 
   a radial dynamic pressure generating groove provided in either one of an outer periphery of the shaft and an inner periphery of the shaft encircling member; and   a first thrust dynamic pressure generating groove provided in either one of a surface of the first flange and a surface of the shaft encircling member, which surfaces face with each other in the axial direction,   wherein:   a space that holds lubricant is formed between the shaft body and the bearing body;   the radial dynamic pressure generating groove includes a protruding section that protrudes in an opposite direction to the second flange in the axial direction from a surface where the first thrust dynamic pressure generating groove is formed;   the clearance between the flange encircling member and the shaft encircling member in the radial direction widens toward the first flange in the axial direction;   the hub includes a groove which is engageable with a disk clamper and is provided annularly in an outer periphery of the hub, the outer periphery of the hub being engageable with a center hole of the recording disk, and the clamper clamping the recording disk to the outer periphery of the hub; and   the protruding section is located inwardly in the radial direction relative to the groove.   
     
     
         9 . The rotating device according to  claim 8 , wherein the protruding section at least partially overlaps a portion of the disk clamper in the axial direction, with the disk clamper being fastened to the hub. 
     
     
         10 . The rotating device according to  claim 8 , further comprising a coil covered by the hub and provided in an unrotatable manner,
 wherein the coil is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         11 . The rotating device according to  claim 8 , further comprising a magnet fixed to the hub,
 wherein the magnet is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         12 . The rotating device according to  claim 8 , wherein:
 the shaft includes an overlap portion where an external piece formed with a hole in the axial direction, and an internal piece to be retained in the hole in the axial direction overlap in the axial direction;   the bearing body includes an inclined face formed in an outer periphery of the shaft encircling member;   the inclined face overlaps the overlap portion in the axial direction;   the inclined face has a larger inclination than an inclination of the flange encircling member; and   the inclined face is disposed outwardly in the radial direction and downwardly in the axial direction relative to the protruding section.   
     
     
         13 . The rotating device according to  claim 8 , further comprising:
 a magnet fixed to the hub; and   a magnetic material provided in an unrotatable manner, formed of an iron-steel plate with a soft magnetism, and including an area facing with the magnet in the axial direction in a non-contact manner therewith,   wherein the magnetic material is disposed outwardly in the radial direction and downwardly in the axial direction relative to the protruding section.   
     
     
         14 . The rotating device according to  claim 8 , wherein an adhesive is present between the first flange and the shaft. 
     
     
         15 . A rotating device configured to rotate a recording disk to be mounted on a hub, the rotating device comprising:
 a shaft body comprising;
 a shaft; 
 a first flange extending outwardly in a radial direction from a side face of the shaft at a first end thereof; 
 a second flange extending outwardly in the radial direction from a side face of the shaft at a second end thereof; and 
 a flange encircling member which extends toward the first flange from an outer periphery of the second flange in an axial direction, and is joined together with the second flange; 
   a bearing body comprising:
 a shaft encircling member which is present in a space between the first flange and the second flange in the axial direction so as to encircle the shaft, is freely rotatable relative to the shaft, and is encircled by the flange encircling member with a clearance; and 
 a ring portion that encircles a part of the first flange; 
   a radial dynamic pressure generating groove provided in either one of an outer periphery of the shaft and an inner periphery of the shaft encircling member; and   a first thrust dynamic pressure generating groove provided in either one of a surface of the first flange and a surface of the shaft encircling member, which surfaces face with each other in the axial direction,   wherein:   a space that holds lubricant is formed between the shaft body and the bearing body;   the radial dynamic pressure generating groove includes a protruding section that protrudes in an opposite direction to the second flange in the axial direction from a surface where the first thrust dynamic pressure generating groove is formed;   the clearance between the flange encircling member and the shaft encircling member in the radial direction widens toward the first flange in the axial direction;   the rotating device further comprises a disk clamper that fastens the recording disk to the hub; and   the protruding section at least partially overlaps a portion of the disk clamper in the axial direction, with the disk clamper being fastened to the hub.   
     
     
         16 . The rotating device according to  claim 15 , further comprising a coil covered by the hub and provided in an unrotatable manner,
 wherein the coil is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         17 . The rotating device according to  claim 15 , further comprising a magnet fixed to the hub,
 wherein the magnet is provided inwardly in the radial direction relative to the disk clamper so as not to overlap the disk clamper in the radial direction with the disk clamper being fastened to the hub, and outwardly in the radial direction relative to the protruding section.   
     
     
         18 . The rotating device according to  claim 15 , wherein:
 the shaft includes an overlap portion where an external piece formed with a hole in the axial direction, and an internal piece to be retained in the hole in the axial direction overlap in the axial direction;   the bearing body includes an inclined face formed in an outer periphery of the shaft encircling member;   the inclined face overlaps the overlap portion in the axial direction;   the inclined face has a larger inclination than an inclination of the flange encircling member; and   the inclined face is disposed outwardly in the radial direction and downwardly in the axial direction relative to the protruding section.   
     
     
         19 . The rotating device according to  claim 15 , further comprising:
 a magnet fixed to the hub; and   a magnetic material provided in an unrotatable manner, formed of an iron-steel plate with a soft magnetism, and including an area facing with the magnet in the axial direction in a non-contact manner therewith,   wherein the magnetic material is disposed outwardly in the radial direction and downwardly in the axial direction relative to the protruding section.   
     
     
         20 . The rotating device according to  claim 15 , wherein an adhesive is provided between the first flange and the shaft.