WO1995034115A1 - Moteur d'axe a faible bruit pour unite de disque de type winchester - Google Patents

Moteur d'axe a faible bruit pour unite de disque de type winchester Download PDF

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Publication number
WO1995034115A1
WO1995034115A1 PCT/US1994/006285 US9406285W WO9534115A1 WO 1995034115 A1 WO1995034115 A1 WO 1995034115A1 US 9406285 W US9406285 W US 9406285W WO 9534115 A1 WO9534115 A1 WO 9534115A1
Authority
WO
WIPO (PCT)
Prior art keywords
stator
shaft
groove
hub
diameter
Prior art date
Application number
PCT/US1994/006285
Other languages
English (en)
Inventor
Siegbert Sadowski
Bernd Dautermann
Stephan Biallas
Original Assignee
Digital Equipment International Ltd.
Digital Equipment International Gmbh
Digital Equipment Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Digital Equipment International Ltd., Digital Equipment International Gmbh, Digital Equipment Corporation filed Critical Digital Equipment International Ltd.
Priority to PCT/US1994/006285 priority Critical patent/WO1995034115A1/fr
Publication of WO1995034115A1 publication Critical patent/WO1995034115A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
    • H02K1/187—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures to inner stators

Definitions

  • the invention relates to data storage disk drives, and particularly to the control of acoustic noise produced by the brushless DC spindle motor in a hard disk drive.
  • Winchester disk drives also known as "hard” disk drives, are used in computer applications for high volume storage of data.
  • Modern hard disk drives contain a disk assembly mounted within a compact housing. The assembly includes a special head arrangement for transferring data to and from circular tracks disposed concentrically on multiple disk surfaces while the disks are rotated on a spindle mechanism at a predetermined speed.
  • the disks are clamped to a spindle hub which is rotatably mount ⁇ ed to a shaft.
  • a motor mounted within the hub rotates the hub and disks.
  • the motor is typically of the brushless DC type, consisting of a stator fixedly attached to the shaft and a permanent magnet ring fixedly attached to the hub so that energization of the stator causes the hub, and thus the disks, to rotate.
  • a disk drive including a resilient member disposed between the stator portion of a brushless DC motor and the spindle shaft of the disk drive to reduce the transference of axial and radial disturbances produced by the motor to the spindle shaft and disk drive housing.
  • a disk drive having a hub rotatably mounted on a spindle shaft.
  • the hub has an inner surface and an outer surface for supporting a disk.
  • a motor provides rotation of the hub about the shaft.
  • the motor includes a magnet fixed to the inner surface of the hub and a stator for interaction with the magnet to provide rotation of the hub during operation of the motor.
  • a resilient member is disposed between the stator and the spindle shaft to reduce the transference of axial and radial disturbances produced by the motor to the spindle shaft and housing.
  • the resilient member may be in physical contact with the stator.
  • the disk drive further includes a stator core located between the stator and the spindle shaft.
  • the resilient member is in physical contact with the stator and the stator core.
  • the resilient member is in physical contact with the stator core and the spindle shaft.
  • two resilient members comprising rubber O-rings are disposed between the stator and the spindle shaft.
  • the disk drive includes a longitudinal stator core fixed to the shaft.
  • the core has an outer surface and two end regions.
  • a groove having a lateral depth is formed concentrically about the outer surface of the core at each end region.
  • the O-rings have a diameter greater that the lateral depth of the grooves.
  • the stator has an inner diameter which is less than the diameter of the outer sur- face of the core at a groove plus the diameter of an uncompressed O-ring.
  • the O-rings are disposed within the grooves and compressed to firmly couple the stator to the shaft.
  • the disk drive in- eludes a longitudinal stator core having an inner surface and two end regions.
  • a groove having a lateral depth is formed concentrically about the inner surface of the core at each end region.
  • the O-rings have a diameter greater that the lateral depth of the grooves.
  • the shaft has an outer diameter which is less than the diameter of the inner sur ⁇ face of the core at a groove plus the diameter of an uncompressed O-ring.
  • the O-rings are disposed within the grooves and compressed to firmly couple the stator core to the shaft.
  • the shaft has an outer surface and two end regions.
  • a groove having a lateral depth is formed concentrically about the outer surface of the shaft at each end region of the shaft such that the grooves formed in the shaft laterally oppose the grooves formed in the stator core.
  • the outer diameter of the shaft taken at a groove in the shaft is less than the diameter of the inner surface of the core taken at a groove in the core plus the diameter of an uncompressed O-ring.
  • the O-rings are disposed between the grooves formed in the stator core and the grooves formed in the shaft and com- pressed to firmly couple the stator core to the shaft.
  • the disk drive includes a longitudinal stator core fixed to the shaft.
  • the core has an outer surface and two end regions.
  • a groove having a lateral depth is formed concentrically about the outer surface of the core at each end region.
  • the O-rings have a diameter greater that the lateral depth of the grooves.
  • the stator has an inner diameter which is less than the diameter of the outer sur ⁇ face of the core at a groove plus the diameter of an uncompressed O-ring.
  • the O-rings are disposed within the grooves and compressed to firmly couple the stator to the shaft.
  • the resilient member comprises a rubber sleeve rather than a pair of O-rings.
  • Figure 1 is a perspective view of a Winchester disk drive including a cut-away view of the disk drive spindle;
  • Figure 2 is a detailed cross-sectional view of the spindle of the disk drive of Figure 1 according to a pre ⁇ ferred embodiment of the invention
  • Figure 3 is a cross-sectional view of the spindle of Figure 2 showing the principles of the invention
  • Figure 3A is a cross-sectional view of the resilient member shown in Figure 3;
  • Figure 4 is a cross-sectional view of an alternate embodiment of a spindle according to the principles of the invention.
  • Figure 5 is a cross-sectional view of another embodi ⁇ ment of a spindle according to the principles of the inven ⁇ tion.
  • Figure 6 is a cross-sectional view of a spindle showing an alternate embodiment of the invention.
  • Figure 6A is a cross-sectional view of the resilient member shown in Figure 6;
  • Figure 7 is a cross-sectional view of an alternate embodiment of a spindle according to the principles of the invention.
  • Figure 8 is a cross-sectional view of another embodi ⁇ ment of a spindle according to the principles of the inven ⁇ tion.
  • disk drive 10 includes a housing 12 containing a spindle 16 secured to an upper baseplate 18 and lower baseplate 20.
  • the spindle 16 supports disks 21 for rotation in the housing 12 about an axis 22.
  • the indi ⁇ vidual disks 21 are separated by spacers 24 and are secured onto the outer surface 25 of a rotatable hub 26 with a clamp ring 28 and bolts 30.
  • a head assembly (not shown) is pro- vided for reading information from and writing information onto disks 21 as they rotate with the hub 26.
  • the spindle 16 includes the hub 26 mounted for rotation about an elongated, stainless steel, stationary spindle shaft 32.
  • the upper and lower ends 34 and 36 of the shaft 32 are rigidly mounted to the upper baseplate 18 and lower baseplate 20 respectively by screws, bolts, or the like.
  • Cartridge bearing assemblies 38 support the hub 26 on the shaft 32 to permit rotation of the hub 26 about the shaft 32.
  • the bearing assemblies 38 include upper bearings 40 and lower bearings 42 near the respective ends 34 and 36 of the shaft 32.
  • the motor 46 includes a stator 48 having stator laminations 52 carrying stator windings 54.
  • An annular permanent rotor magnet 56 is fixedly attached or bonded to the inner surface 58 of the hub 26.
  • Application of current to the windings 54 of the stator 48 induces magnetic flux in the stator laminations 52 which interact with the rotor magnet 56 to impart rotational motion to the hub 26 in a manner well known in the art.
  • the rotor magnet 56 and hub 26 thereby form a rotor 57.
  • Hall effect switches 55 monitor magnetic flux to control the speed of the rotor 57 in a conventional manner.
  • a resil ⁇ ient member 59 is disposed between the stator 48 and the spindle shaft 32.
  • a longitudi ⁇ nal stator core 60 is rigidly fixed to the shaft 32.
  • the stator core 60 is a plastic support piece for convenient mounting of the stator 48 on the shaft 32.
  • the resilient members 59 are in physical contact with the stator 48 and the stator core 60.
  • Resilient members 59 are here provided by a pair of rubber gaskets or O-rings 61. The resilient members allow for a limited amount of movement of the stator 48 relative to the shaft 32. Mechanical resonances are thus shifted to lower, less critical frequencies.
  • the stator core 60 has an outer surface 62, an inner surface 63, and two end regions 64 and 66. In the vicinity of each end region 64 and 66 there is formed concentrically about the outer surface 62 a groove 68, 70 having a lateral depth 72.
  • the O-rings 61 in their uncompressed state (see Fig.
  • the grooves 68 and 70 formed in the outer surface 62 of the stator core 60 are of a rectangular cross section 80.
  • the upper and lower walls 84 and 86 of the cross section 80 serve to prevent axial motion of the O-rings 61, providing a substantially rigid coupling of the stator 48 to the shaft 32 in the perpendicular direc- tion 88 while maintaining an effective radial decoupling of the stator 48 from the shaft 32.
  • the grooves 68 and 70 may alternatively be formed with other cross sectional shapes: for example, a notch or parabolic cross-section would pro ⁇ vide advantageous self-centering of the O-rings 61 within the grooves 68 and 70.
  • the shaft 32 has an outer surface 90 and two end regions 92 and 94. In the vicinity of each end region 92 and 94 there is formed concentrically about the outer surface 90 a groove 96, 98 having a lateral depth 100.
  • the O-rings 61 in their uncompressed state (see Fig. 3A) have a diameter 74 greater than the lateral depth 100 of the re- spective grooves 96 and 98.
  • the stator 48 is fixedly at ⁇ tached or bonded to the stator core 60.
  • the inner diameter 102 of the stator core 60 is less than the diameter 104 of the outer surface 90 of the shaft 32 at a groove 96, 98 plus the diameter 74 of an uncompressed O-ring 61.
  • the O-rings 61 disposed within the grooves 96 and 98 are compressed to firmly but resiliently couple the stator 48 to the shaft 32.
  • Axial and radial disturbances produced by the motor 46 are damped by the resilient 0- rings, thus decoupling the disturbances from the shaft 32.
  • the grooves 96 and 98 formed in the outer surface 90 of the shaft 32 are of a rectangular cross section 106.
  • the upper and lower walls 108 and 110 of the cross section 106 serve to prevent axial motion of the 0- rings 61, providing a substantially rigid coupling of the stator 48 to the shaft 32 in the perpendicular direction 88 while maintaining an effective radial decoupling of the stator 48 from the shaft 32.
  • other cross-sectional shapes for the grooves 96 and 98 such as a notch or para ⁇ bolic cross section, may be advantageous. Referring now to Figure 5 there is shown another em ⁇ bodiment.
  • This embodiment is substantially the same as the embodiment shown in Figure 4 with the addition of grooves 112 and 114 formed in the inner surface 63 of the stator core 60 in a position opposing the grooves 96 and 98 respec- tively formed in the spindle shaft 32.
  • the lateral depth 100 of the grooves 96 and 98 and the lateral depth 116 of the grooves 112 and 114 is such that an inner diameter 118 of the stator core taken at a groove 112 or 114 is less than a diameter 120 of the shaft 32 at a groove 96 or 98 plus the diameter 74 of an uncompressed O-ring 61.
  • the stator core 60 is thus firmly supported on the shaft 32 by the O-rings 61.
  • the grooves 112 and 114 formed in the inner surface 61 of the stator core 60 are of a rectan ⁇ gular cross section 122, though other cross sectional shapes may be advantageous.
  • the grooves 112 and 114 provide perpen ⁇ dicular stability while still maintaining effective radial decoupling of the stator 48 from the shaft 32.
  • the resilient member 59 disposed between the stator 48 and the spindle shaft 32 is embodied as a resilient sleeve 130, which can be composed for example of a rubber material.
  • the longitudinal stator core 60 is rigidly fixed to the shaft 32.
  • the resilient sleeve 130 is in physical contact with the stator 48 and the stator core 60.
  • the resilient sleeve 130 allows for a limited amount of movement of the stator 48 relative to the shaft 32, as did the rubber O-rings 61 of the previous embodi ⁇ ments. Mechanical resonances are thereby shifted to lower, less critical frequencies.
  • the stator core 60 has an outer surface 62 and an inner surface 63. There is formed concen ⁇ trically about the outer surface 62 a groove 168 having a lateral depth 172.
  • the resilient sleeve 130 in its uncompressed state has a diameter 174 greater than the lateral depth 172 of the groove 168, so that the inner diameter 76 of the stator 48 is less than the diameter 178 of the outer surface 62 of the core 60 at the groove 168 plus the diameter 174 of the uncompressed resilient sleeve 130.
  • the groove 168 formed in the outer surface 62 of the stator core 60 is of a rectangular cross section 180.
  • the upper and lower walls 184 and 186 of the cross section 180 serve to prevent axial motion of the resilient sleeve 130, providing a substantial ⁇ ly rigid coupling of the stator 48 to the shaft 32 in the perpendicular direction 88 while maintaining an effective radial decoupling of the stator 48 from the shaft 32.
  • the groove 168 may alternatively be formed with other cross sectional shapes: for example, a trapezoic cross-section would provide advantageous self-centering of the sleeve 130 within the groove 168.
  • the resilient sleeve 130 is in physical contact with the spindle shaft 32 and the stator core 60.
  • the shaft 32 has an outer surface 90.
  • the resilient sleeve 130 in its uncompressed state (see Fig. 6A) has a diameter 174 greater than the lateral depth 200 of the groove 196.
  • the stator 48 is fixedly attached or bonded to the stator core 60.
  • the inner diameter 202 of the stator core 60 is less than the diameter 204 of the outer surface 90 of the shaft 32 at the groove 196 plus the diameter 174 of the uncompressed resilient sleeve 130.
  • the resilient sleeve 130 disposed within the groove 196 is compressed to firmly but resiliently couple the stator 48 to the shaft 32.
  • Axial and radial disturbances produced by the motor 46 are damped by the resilient sleeve 130, thus decoupling the disturbances from the shaft 32.
  • the groove 196 formed in the outer surface 90 of the shaft 32 is of a rectangular cross section 206.
  • the upper and lower walls 208 and 210 of the cross section 206 serve to prevent axial motion of the resilient sleeve 130, providing a substantially rigid coupling of the stator 48 to the shaft 32 in the perpendicular direction 188 while maintaining an effective radial decoupling of the stator 48 from the shaft 32.
  • other cross-sectional shapes for the groove 196 such as a trapezoic cross sec ⁇ tion, may be advantageous.
  • FIG. 8 there is shown another em ⁇ bodiment.
  • This embodiment is substantially the same as the embodiment shown in Figure 7 with the addition of a groove 212 formed in the inner surface 63 of the stator core 60 in a position opposing the groove 196 formed in the spindle shaft 32.
  • the lateral depth 200 of the groove 196 and the lateral depth 216 of the groove 212 is such that an inner diameter 218 of the stator core taken at the groove 212 is less than a diameter 220 of the shaft 32 at the groove 196 plus the diameter 174 of the uncompressed resilient sleeve 130.
  • the stator core 60 is thus firmly supported on the shaft 32 by the resilient sleeve 130.
  • the groove 212 formed in the inner surface 61 of the stator core 60 is of a rectangular cross section 222, though other cross sectional shapes may be advantageous.
  • the grooves 212 and 196 provide perpendicular stability while still maintaining effective radial decoupling of the stator 48 from the shaft 32.
  • the resilient coupling of the stator 48 to the spindle shaft 32 has been described in terms of its useful ⁇ ness in Winchester disk drives, it may be found useful to provide a resilient member between the stator and shaft in any application where it is desirable to reduce the trans ⁇ ference of acoustic noise from a brushless DC motor to a housing.
  • the resilient coupling of the stator 48 to the spindle shaft 32 can be implemented in a variety of ways to be effective in motors employing various spindle designs.
  • the stator core 60 shown in Figures 3 and 4 provides a convenient mechanism for mounting the stator 48 on the shaft 32 but is not required.
  • the resil ⁇ ient couplings could reside in direct physical contact with the stator 48 and the shaft 32, with grooves being formed in either the stator 48, the shaft 32, or both.
  • the resilient member 59 is effectively constructed of a rubber material, other materials may also be effective, such as flexible plastics.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Permanent Magnet Type Synchronous Machine (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

Un accouplement élastique est prévu entre le stator et l'axe d'une unité de disque de type Winchester pour réduire la transmission à l'axe et au boîtier des vibrations axiales et radiales produites par le moteur, ce qui se traduit par une réduction concomitante du bruit acoustique.
PCT/US1994/006285 1994-06-09 1994-06-09 Moteur d'axe a faible bruit pour unite de disque de type winchester WO1995034115A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US1994/006285 WO1995034115A1 (fr) 1994-06-09 1994-06-09 Moteur d'axe a faible bruit pour unite de disque de type winchester

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1994/006285 WO1995034115A1 (fr) 1994-06-09 1994-06-09 Moteur d'axe a faible bruit pour unite de disque de type winchester

Publications (1)

Publication Number Publication Date
WO1995034115A1 true WO1995034115A1 (fr) 1995-12-14

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Application Number Title Priority Date Filing Date
PCT/US1994/006285 WO1995034115A1 (fr) 1994-06-09 1994-06-09 Moteur d'axe a faible bruit pour unite de disque de type winchester

Country Status (1)

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WO (1) WO1995034115A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0911943A1 (fr) * 1997-09-26 1999-04-28 Minebea Co., Ltd. Moteur pour l'entraínement d'un disque magnétique

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2350721A1 (fr) * 1976-05-04 1977-12-02 Skf Kugellagerfabriken Gmbh Moteur electrique a rotor exterieur
EP0149228A2 (fr) * 1983-12-28 1985-07-24 Papst-Motoren GmbH & Co. KG Moteur électrique, en particulier moteur à courant continu sans collecteur
GB2252209A (en) * 1991-01-23 1992-07-29 Panavision Int Lp Noise and vibration dampened electric motor such as for use with a sound movie camera
US5227686A (en) * 1991-04-12 1993-07-13 Nagano Nidec Corporation Spindle motor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2350721A1 (fr) * 1976-05-04 1977-12-02 Skf Kugellagerfabriken Gmbh Moteur electrique a rotor exterieur
EP0149228A2 (fr) * 1983-12-28 1985-07-24 Papst-Motoren GmbH & Co. KG Moteur électrique, en particulier moteur à courant continu sans collecteur
EP0425478A2 (fr) * 1983-12-28 1991-05-02 Papst Licensing GmbH Moteur à rotor extérieur, en particulier moteur à courant continu sans collecteur
GB2252209A (en) * 1991-01-23 1992-07-29 Panavision Int Lp Noise and vibration dampened electric motor such as for use with a sound movie camera
US5227686A (en) * 1991-04-12 1993-07-13 Nagano Nidec Corporation Spindle motor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0911943A1 (fr) * 1997-09-26 1999-04-28 Minebea Co., Ltd. Moteur pour l'entraínement d'un disque magnétique
US6137196A (en) * 1997-09-26 2000-10-24 Minebea Co., Ltd. Motor for driving magnetic disk

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