Method for working magnetic disk mount portion of motor hub of the hard disk drive apparatus, thus obtained motor hub, and motor including the same

Abstract

A grinding operation is effected by rotating the motor hub in high speed around the central axis thereof, and urging the outer peripheral surface of a grinding wheel rotated in high speed around the central axis against the upper surface of the outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk. The surface of the flange can be worked in high precision. Thus, a compact, large capacity, and reliable hard disk drive apparatus is to be provided by reducing the rotational runout of the magnetic disk incorporated within the hard disk drive apparatus.

What is claimed is:  
     
         1 . A method for working a magnetic disk mount portion of a motor hub of the hard disk drive apparatus including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, the method being characterized in that: 
 the motor hub is rotated in high speed around the central axis thereof, and outer peripheral surface of a grinding wheel rotated in high speed around the central axis thereof is urged on the upper surface of the outwardly extending flange.    
     
     
         2 . The method for working a magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 1 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub through the displacement of the carriage.  
     
     
         3 . The method for working the magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 1 , wherein said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         4 . The method for working the magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 1 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub by pivoting the rotationally driving apparatus with respect to the carriage as well as the displacement of the carriage.  
     
     
         5 . A method for working a magnetic disk mount portion of a motor hub of the hard disk drive apparatus including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, the method being characterized in that: 
 the motor hub is rotated in high speed around the central axis thereof, and the grinding wheel is also rotated in high speed around the central axis thereof, the grinding wheel includes a pair of tapered surfaces extending axially outwardly to reduce the diameter thereof and orthogonal with each other from an edge defined at the intersection of the tapered surfaces, wherein the grinding operation is effected by urging the tapered surfaces against the disk fitting surface and the upper surface of the outwardly extending flange respectively.    
     
     
         6 . The method for working a magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 5 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub through the displacement of the carriage.  
     
     
         7 . The method for working the magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 5 , wherein said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         8 . The method for working the magnetic disk mount portion of the motor hub of the hard disk drive apparatus as claimed in  claim 5 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the grinding wheel is urged against the magnetic disk mount portion of the hub by pivoting the rotationally driving apparatus with respect to the carriage as well as the displacement of the carriage.  
     
     
         9 . A motor hub of the hard disk drive apparatus comprising a magnetic disk mount portion including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, the motor hub being characterized in that: 
 the motor hub is rotated in high speed around the central axis thereof, and the upper surface of the outwardly extending flange is adapted to be ground by the outer peripheral surface of the grinding wheel rotated in high speed around the axis thereof.    
     
     
         10 . The motor hub of the hard disk drive apparatus as claimed in  claim 9 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the magnetic disk mount portion of the hub is ground through the displacement of the carriage.  
     
     
         11 . The motor hub of the hard disk drive apparatus as claimed in  claim 9 , wherein said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         12 . The motor hub of the hard disk drive apparatus as claimed in  claim 9 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage, and by displacing the carriage.  
     
     
         13 . A motor hub of the hard disk drive apparatus comprising a magnetic disk mount portion including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, the motor hub being characterized in that: 
 the motor hub is rotated in high speed around the central axis thereof, and the grinding wheel is also rotated in high speed around the central axis thereof, the grinding wheel includes a pair of tapered surfaces extending axially outwardly to reduce the diameter thereof and orthogonal with each other from an edge defined at the intersection of the tapered surfaces, wherein the grinding operation is effected by urging the tapered surfaces against the disk fitting surface and the upper surface of the outwardly extending flange respectively.    
     
     
         14 . The motor hub of the hard disk drive apparatus as claimed in  claim 13 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the magnetic disk mount portion of the hub is ground through the displacement of the carriage.  
     
     
         15 . The motor hub of the hard disk drive apparatus as claimed in clam  13 , wherein said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         16 . The motor hub of the hard disk drive apparatus as claimed in  claim 13 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so an to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage, and by displacing the carriage.  
     
     
         17 . A motor for the hard disk drive apparatus including a motor hub around the outer periphery of which a magnetic disk or a plurality of magnetic disks are to be provided, the motor hub is journalled on a base through a bearing apparatus, the motor being characterized in that the motor hub is provided with a magnetic disk mount portion including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, wherein the upper surface of the outwardly extending flange of the motor hub rotated in high speed around the central axis thereof is adapted to be ground by an outer peripheral surface of a grinding wheel rotated in high speed around the central axis thereof.  
     
     
         18 . The motor for the hard disk drive apparatus as claimed in  claim 17 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the magnetic disk mount portion of the hub is ground through the displacement of the carriage.  
     
     
         19 . The motor for the hard disk drive apparatus as claimed in  claim 17 , wherein said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         20 . The motor for the hard disk drive apparatus as claimed in  claim 17 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage, and by displacing the carriage.  
     
     
         21 . A motor for the hard disk drive apparatus including a motor hub around the outer periphery of which a magnetic disk or a plurality of magnetic disks are to be provided, the motor hub is journalled on a base through a bearing apparatus, the motor being characterized in that the motor hub is provided with a magnetic disk mount portion including a cylindrical disk fitting surface around which a central aperture of a magnetic disk or disks are to be fit, and an outwardly extending flange for supporting on its upper surface the lower surface of the central portion of the magnetic disk, wherein the disk fitting surface and the upper surface of the outwardly extending flange of the motor hub rotated in high speed around the central axis thereof are adapted to be ground by a pair of tapered surfaces of a grinding wheel rotated in high speed around the central axis thereof, the tapered surfaces extending axially outwardly with reducing the diameter thereof from an edge define a right angle at the edge defined therebetween.  
     
     
         22 . The motor for the hard disk drive apparatus as claimed in  claim 21 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, wherein the magnetic disk mount portion of the hub is ground through the displacement of the carriage.  
     
     
         23 . The motor for the hard disk drive apparatus as claimed in  claim 21 , wherein Said grinding wheel is attached to the spindle of the rotationally driving apparatus connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage.  
     
     
         24 . The motor for the hard disk drive apparatus as claimed in  claim 21 , wherein said grinding wheel is attached to a spindle of the rotationally driving apparatus connected to the carriage displaceable in X, Y, and Z directions, and the rotationally driving apparatus is connected to the carriage so as to pivot around the axis extending orthogonal to the central axis of the motor hub, wherein the magnetic disk mount portion of the hub is ground by pivoting the rotationally driving apparatus with respect to the carriage, and by displacing the carriage.