JPH11126413A - Disk storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a disk storage have a simple assembly structure while securing a high clean degree by uniformly distribution forming plural openings on the end surface of a disk support member and containing a shield ring for sealing the internal space of a motor from a clean room adjacent to these openings. SOLUTION: An outside rotator cup 17 extends downward to the extent surrounding a control magnet, and a space part between an end surface wall 17A and the end part of this magnet 13 is filled up with a prescribed filler. A bearing device of a bearing 32 consisting of two ball bearings 33 seals a motor inside space and the clean room by a magnetic fluid seal. Magnetically acting stator part and rotator part are provided nearly perfectly in the inside of the space 46 surrounded by a disk support part 66. Further, the bearing is provided on a curved spring fitted to a cap on the end part parting far from the clean room 49 of a bushing. Then, this bushing is connected integrally with an assembly flange 83.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk storage device, and more particularly, to a disk storage device having a housing forming a clean room, a storage disk disposed in the clean room, and a disk drive for driving the same. The disk drive includes a stator having windings, and an outer rotor having a permanent magnet rotor magnet and a soft magnetic yoke which coaxially surround the stator by forming a substantially cylindrical gap. And a boss having a disk support which is concentrically and non-rotatably coupled to the yoke and is provided in the clean room and accommodates at least one storage disk and which can be inserted into a center hole of the storage disk. Using the provided disk drive.

[0002]

2. Description of the Related Art In a known disk drive of this type (FIG. 3 and FIG. 4 of DE-A-3135385), a relatively strong member is provided as a boss for accommodating a storage disk, and this member is provided. A magnetically acting stator part and a rotation provided with an axially extending bearing frame in the region of the disk support, non-rotatably connected to the shaft by means of a bearing bush pressed or cast into the boss. The sub-portion, i.e. the stator winding and the small axial dimension of the motor magnet cooperating therewith, are covered together with the disk support.

[0003]

In the case of a disk storage device, the demand for reducing the space occupied by the storage device is increasing, and the demand for the cleanliness of a clean room is also increasing. In general, there is an increasing demand for simplification of an assembly structure or a manufacturing process.

Accordingly, the basic object of the present invention is to reduce the space occupied, in particular by minimizing the size of the disk storage device, especially in the axial direction, and to attain a high degree of cleanliness of the clean room, An object of the present invention is to provide a disk storage device having a mounting structure.

[0005]

This object is achieved according to the present invention by the following disk storage device. That is, a housing that hermetically defines a clean room, at least one storage disk disposed in the clean room so as to rotate about an axis and having a central hole, and mounted substantially inside the clean room. A DC motor of a non-collecting electron, wherein the DC motor comprises a stator having at least six radially extending magnetic pole pieces substantially uniformly distributed around the axis. A stator groove is formed between the pole pieces, and the DC motor further includes a stator winding having at least three phases, and the same number of coils as the number of the pole pieces. A coil is wound about a corresponding one of the pole pieces, and the DC motor further comprises a rotor mounted on the stator to rotate about the axis. Includes a surface on which a permanent magnet ring is mounted, the pole piece and the A cylindrical gap is formed between adjacent surfaces of the permanent magnet ring, and the rotor further includes a disk support member having a cylindrical portion extending through the central hole of the at least one disk. A plurality of openings substantially uniformly distributed on an end surface of the disk support member for mounting the at least one disk on the disk support member; and an internal cavity of the motor adjacent the opening. The disk storage device, further comprising a shielding ring for sealing the device from the clean room.
In this configuration, the magnetically active part of the drive motor occupies most of the space required for holding a storage disk, especially a magnetic hard disk or other type of storage disk, for example an optical storage disk. .

[0006]

DETAILED DESCRIPTION OF THE INVENTION Preferably, the DC motor further comprises at least one seal for generally reducing migration of foreign matter from the motor to the clean room. Preferably, at least one seal is arranged between the rotor and a fixed part of the disk storage device. Preferably, at least one seal is formed as a magnetic fluid seal. The other dependent claims give preferred embodiments of the invention. The stator windings and the motor magnets cooperating therewith are preferably provided in the space enclosed by the disk support at least two-thirds of their axial dimension. If the magnetically acting stator part and rotor part are almost completely in this space, a particularly space-saving overall structure is obtained.

The diameter of the center hole of a storage disk such as a magnetic hard disk is standardized, and its size is limited to a fixed value. On the other hand, the generation of drive energy requires some motor dimensions. For example, in the case of a known small storage disk having a center hole diameter of only 25 mm, the relationship is particularly critical. In order to prepare as many places as possible for the magnetically acting motor part in the space of the center hole of the storage disk having a limited diameter,
In a development of the invention, the wall thickness of the disk support of the boss is made as small as possible in view of the mechanical strength. In this case, the wall thickness of the disk support is preferably equal to or smaller than the wall thickness of the portion of the magnetic circuit member concentric with the disk support.

Further, taking into account the predetermined diameter of the center hole of the storage disk and the required mechanical strength of the boss for the magnetically acting motor part, it is effective to provide the largest cross section, The support preferably has a cylindrical outer peripheral surface, i.e. a peripheral surface without known bearing frames or bearing ribs.

At least the surface of the boss in the clean room is
Even if the disk drive is used for a long time, no or practically any dust should be released into the clean room by, for example, oxidizing action. The boss is a material suitable for a clean room even after machining such as cutting, grinding and polishing, that is, in the case of a storage disk in a clean room containing a storage disk without performing post-corrosion treatment after machining. Preferably, it is made of a material that conforms to the strict cleaning conditions required for the cleaning. By configuring the boss in this way, after the boss is combined with the drive motor, the outer peripheral surface of the disk support can be superfinished, for example, polished or turned, in order to align it with the axis of rotation.

This is because extremely high mechanical precision is required in a magnetic disk storage device, especially a drive device such as a hard disk, in response to an increase in track density of a track corresponding to a read / write head moving in conjunction with the storage hard disk. Is effective to guarantee. During rotation,
The boss surface shifts from the theoretical value of mechanical accuracy, and the maximum value of the difference in the radial shift of the boss surface is determined by TIR (Total Indicated).
Run-out), for example, about 5 to 15 μm, and the deviation of the displacement during operation from the average value of the radial displacement of the boss surface during rotation is usually called non-repetitive runout, and the minimum value of the deviation is , 0.2-0.5 μm (manufacturers guarantee this value). Furthermore, the radial accuracy of the cylindrical portion of the disk support portion of the boss is about 5 to 30 μm, and the flatness of the flat surface of the boss is preferably about 1 μm or less.

[0011] In order to meet the strong demands of minimizing concentric rotation or vibration of the boss in the case of disk storage, such precision machining of the assembled boss is often necessary. Bosses made of light metals, especially aluminum or aluminum alloys, have been found to be particularly effective.
The light metal boss retains suitability for a clean room without post-processing after machining. This allows the turning to be performed with the required precision, for example by means of a diamond tool, which is more economical in the case of disk supports with a cylindrical outer surface, in particular than grinding. The boss is extruded or cast, and the magnetic circuit member (yoke)
It is preferable to be thermocompression-bonded. However, in principle, it is also conceivable, for example, to bond these components to one another as another possibility of connecting the boss and the yoke.

The magnetic circuit member can be formed in a cup shape by a method known per se. In particular, an annular magnetic circuit element can be provided, in which case a magnetic shielding ring extending radially inward from the cleanroom-side axial end of the annular magnetic circuit element is suitably fitted into the boss. In this way, an effective magnetic shielding of the storage disk against the induction and drive motors requiring magnetic flux is obtained. The combination of the magnetic circuit ring member and the shielding ring can be economically manufactured in a cup shape. The shielding ring can be made relatively thin, so that the overall axial length of the drive is further reduced, and if this length is the same, the closed end of the component group consisting of bosses, magnetic circuit components and motor magnets A lot of space can be used for the end wall of the boss in the part. The magnetic circuit element can be rationally formed as a rolling ring, in particular a steel ring, or as a tube section.

The rotor and the boss can be fixedly connected to a shaft supported at least in part on a bearing device provided in the stator of the drive motor. In that case, the bearing bush for accommodating the shaft can be formed integrally with the magnetic circuit member (yoke) if it is formed in the shape of a cup, or in particular integrally with the boss. Therefore, no special components for the bush are required.
However, the rotor and the boss can also be rotatably mounted on a fixed shaft via a bearing device with a modified development, in which case the windings of the stator windings are rationalized outside the drive through the fixed shaft. Is taken out.

A control magnet, for example, which cooperates with a stationary magnetic field sensitive rotational position sensor device intended to generate a rectified signal and possibly additional control signals, for example a signal for a predetermined reference position of the rotor. A control magnet in the form of a ring is rationally coupled to the rotor and boss unit. In this case, it is preferable that the control magnet is provided on the axially open side of the unit including the rotor and the boss. The control magnet can be axially aligned with the motor magnet. In some cases, the motor magnet itself can also be used as the control magnet. The rotation position sensor device is preferably mounted on a printed circuit board that is axially opposed to the axially open side of the unit including the rotor and the boss. Reference numerals attached to the embodiments of the claims are for ease of understanding, and are not necessarily limited to those shown in the drawings.

[0015]

Next, preferred embodiments of the present invention will be described in more detail. The subject matter of the invention described in claim 1 mainly corresponds to the following embodiments 4 and 5, but other embodiments cooperate with each other for understanding the invention. Referred to.

(Embodiment 1) In FIGS. 1 and 2, a drive motor indicated by reference numeral 18 is a stator lamination plate 10.
Is provided. The stator laminate 10 is radially symmetric with respect to the central rotation axis 10A, and has an annular central portion 10B.
It has. The stator laminate 10 forms six stator poles 11A to 11F which are substantially T-shaped in the plan view shown in FIG. 1 and are spaced 60 ° apart from each other. ing. Instead of a laminate, for example, a sintered iron core can be used.

The pole pieces 12A to 12F of the stator poles, together with the motor magnet 13 of the permanent magnet, form a substantially cylindrical air gap 14. As shown in FIG. 1, the motor magnet 13 is radially magnetized with four poles in the circumferential direction, that is, the motor magnet 13 has four portions 13A to 13D, and has an annular shape.
There are two magnetic north poles and two magnetic south poles 15 and 16 alternately facing inwardly toward the air gap 14 of the vehicle. Pole 15,
16 has a width of approximately 180 ° electrical angle (mechanically equivalent to 90 °) in the illustrated embodiment. In this manner, a substantially rectangular or trapezoidal magnetization is obtained in the circumferential direction of the gap 14.

The motor magnet 13 is a magnetic circuit member (yoke).
And is mounted in an outer rotor cup 17 of a soft magnetic material serving as a magnetic shield, for example glued to this cup. The outer rotor cup 17 and the magnet 13 constitute the outer rotor 30. The outer rotor cup 17 has an end wall 17A and a cylindrical peripheral wall 17B. In the case of the motor magnet 13, this can in particular be a rubber magnet or a synthetic resin bonded magnet. Instead of an integral magnet ring, a shell-shaped magnet segment can be glued or otherwise fixed thereto.

Particularly suitable materials for the magnet ring or magnet segment are magnetic materials bonded with a synthetic (resin) binder,
A mixture of hard (hard) ferrite and an elastomeric material, a porcelain (ceramic) magnet material or samarium cobalt. In the illustrated embodiment, each pole extends in effect at an electrical angle of 180 °, but can be operated with smaller poles. However, to obtain high motor output, the width of the rotor poles must be at least 120 electrical degrees.

The stator poles 11A to 11F define a total of six stator grooves 20A to 20F. A three-phase stator winding is fitted in this groove. In that case, each of the three-phase windings comprises two (paired) coils 21, 22; 23, 24 and 25, 26, each deflected by an electrical angle of 120 °, each of which comprises one stator. It is wound around poles 11A to 11F.

As shown in FIG. 1, two serially connected coils of each phase winding are provided on opposite sides in the diameter direction. Although not shown, these coils are particularly wound in two turns. As can be seen from the schematic diagram of FIG. 1, the respective overlap between the coils 21 to 26 is avoided. In this way, a particularly short coil head 27 (FIG. 2) is obtained. The groove openings 28A to 28F have an electrical angle of 3
° to 30 ° width. When the stator windings are formed, the grooves 20A to 20F are thereby substantially filled. In general, lids for groove openings 28A-28F are not required.

The structure of the electric motor shown here is based on a stator groove.
Since the depth of 20A to 20F can be made relatively small, a relatively large stator internal hole 29 can be obtained. Internal hole
The ratio between the diameter I of 29 and the stator outer diameter E of the pole piece 12 is
A minimum of 0.35 is reliably obtained. The value of I / E should be between 0.4 and
It is preferably in the range of 0.7. Preferably, the ratio of the axial length L of the stator core to the stator outer diameter E is equal to or less than one. This dimensional ratio is particularly important for stably supporting the rotor. Such support is particularly important when driving a disk storage device. In addition, the overall resistance of the stator winding is particularly low.

In order to support the rotor 30, a short shaft 32 is fixed at the center of the outer rotor cup 17 via a bearing bush 31 formed on the outer rotor cup 17, as shown in FIG. This short axis supports the stator laminate 10 via ball bearings 33 provided axially spaced from one another and bearings in a cylindrical bushing 34 fixed to an assembly flange 35.
33, 33 are held through.

The outer rotor cup 17 is provided with a cylindrical disk support 36, not shown in FIG. 1, and a boss 37 of a fixed disk storage device, particularly made of light metal, is fixed by, for example, shrink fitting. ing. One or several fixed storage disks 39, especially magnetic fixed storage disks, are attached to the disk support 36, in which case the disk support 36 is passed through the center hole 40 of the storage disk 39,
The storage disks 39 are held axially apart from one another by suitable spacers 41 and are fixed to the boss 37 by fastening means, not shown, known per se.

In the case of the embodiment shown in FIG.
The magnetically acting stator and rotor portions, i.e., the motor magnet 13 and the stator windings 21 to 26, have a space in which at least about 2/3 of their axial dimension is surrounded by the disk support 36. It has entered part 46. The wall thickness of the disk support 36 of the boss 37 is smaller than the cylindrical peripheral wall 17B forming the magnetic circuit member of the outer rotor cup 17, and therefore the motor parts 13, 17, within the well-defined central hole 40. 19
Is prepared for the largest cross section. In particular, the wall thickness of the disk support 36 is made as small as possible in terms of mechanical strength. In order to increase the dimensional stability of the boss 37,
This boss has a flange 47 at the open end of the element consisting of the boss 37, the outer rotor cup 17 and the motor magnet 13.
A radially outwardly protruding radially outwardly extending flange portion (outer edge portion) 47 that functions to support the fixed storage disk 39 adjacent to the outer peripheral portion in the axial direction.

The boss 37, together with the storage disk 39 supported thereon, is inside a clean room 49, not shown in detail, but defined by a housing part of the disk storage device in a manner known per se. . In that case, the assembly flange 35 forms part of the boundary of the clean room with respect to the lower side of FIG. The upper bearing 33 in FIG. 2 is located between the shoulder 51 of the bushing 34 and the spacer ring 52, and the side of the ring 52 opposite to the bearing 33 contacts the lower side of the bearing bush 31. The lower end of the short shaft 32 is formed in a spherical shape, and is suitably supported by a thrust bearing (not shown). Retaining ring 55 in annular groove 54 of shaft 32 near lower end 53
, And two spring washers 56 are interposed on the upper side. The spring washer 56 is in contact with the intermediate ring 57. The lower ball bearing 33 is between the intermediate ring 57 and another shoulder 58 of the bushing.

The assembly flange 35 comprises a printed circuit board 38 on which possibly rectifying electronics and / or other circuit elements, for example for adjusting the rotational speed, can be provided. The printed circuit board 38 includes, in particular, three rotational position sensors 4.
2, 43 and 44 are provided, which in the embodiment shown are magnetic field sensors such as Hall generators, magnetoresistive plates, magnetic diodes and the like. Particularly, a bistable connection hole integrated circuit is preferable. Rotor poles 15 and 16 with electrical angle of 180 °
, The motor magnet 13 can be used directly as a control magnet for the position sensors 42, 43, 44. In the case of the embodiment shown in FIG.
The reference numerals 42, 43, and 44 face the magnet 13 that controls this in the axial direction.

However, for example, a rotational position sensor
As shown by a broken line in FIG. 2, the magnet 13 may be provided so as to be radially opposed to the magnet 13 for controlling the magnet. The rotational position sensors 42, 43, 44 are provided at the correct positions with respect to the coils 21 to 26 in the circumferential direction so that the change of the connection state of the sensors takes place almost simultaneously with the zero crossing point of the corresponding coil voltage. This means that in the embodiment shown in FIG. 1, the rotational position sensor is connected to the groove openings 28A, 28B and
Achieved by offsetting the mechanical angle by 15 ° with respect to the center of 28C.

(Embodiment 2) The embodiment shown in FIG. 3 is shown in FIG. 2 in that a control magnet 45 different from the motor magnet 13 is provided for controlling the rotational position sensors 42, 43 and 44. Different from the embodiment. Control magnet 45, outer rotor cup
At the open end of 17, a flange 17C protruding radially outward from the peripheral wall 17B is provided radially outside the motor magnet 13 below the flange 17C. The outer rotor cup 17 and the boss 37 ', in the embodiment shown in FIG. 3, just terminate at one another at the open ends.

The terminals of one of the coils 21, 26 at the connection point of the printed circuit board 38 are schematically indicated by the reference numeral 59. A connection cable 60 is drawn out of the printed circuit board 38 through a through hole 61 of the assembly flange 35 to the outside.

(Embodiment 3) FIG. 4 shows another embodiment of the disk drive device. In this embodiment, unlike the configuration shown in FIG. 2 and FIG.
64 has an end face wall 64A adjacent to the end face wall 17A of the outer rotor cup 17 and integrally formed with the bearing bush 65 of the shaft 32.

At the end of the boss 64 far away from the end surface 64A of the disk support portion 66, a flange bent outward in the radial direction is provided.
The flange 67 is concentric with the disk support 66 and transitions to a peripheral wall 68 having a larger diameter than the disk support 66. The peripheral wall 68 surrounds the flange 17C of the outer rotor cup 17 radially outward.

The joint between the flange 17C and the peripheral wall 68 is sealed by a varnish, an adhesive or the like as indicated by reference numeral 69. In this way, as in the case of FIG. 3, dust is prevented from being radially released from the flange 17C to the outside and entering the clean room. A control magnet 45 cooperating with a rotational position sensor (of which only the sensor 42 is shown in FIG. 4) is arranged in the axial direction with the motor magnet 13, and is located on the side far from the end face 17 </ b> A of the magnet 13. Is provided.

The outer rotor cup 17 is shown in FIG.
The control magnet 45 also extends downward so as to surround it. End wall
The space between 17A and the end of magnet 13 facing this end wall is filled with an adhesive or other filler. The bearing device of the shaft 32 composed of the two ball bearings 33 is hermetically sealed with respect to the inner space of the motor and the clean room by a magnetic fluid seal.

The magnetic fluid seal 72 includes two annular magnetic pole pieces 7.
3, 74, a permanent magnet ring 75 between these two pole pieces, and a magnetic fluid (not shown) inserted between the magnet ring 75 and a portion 77 of the shaft 32. I have. This type of seal is known by the trade name "ferrofluidic seal". The seal 72 particularly effectively prevents dust from being released from the bearing device into the clean room 49. The seal 72 is provided adjacent to the bearing bush 65 but spaced apart in the axial direction. This prevents the magnetic fluid from being pulled out of the seal 72 by capillary action.

As can be seen from FIG. 4, the magnetically acting stator portion and the rotor portion are provided almost completely inside the space 46 surrounded by the disk support 66. FIG. 4 shows a thrust bearing of the shaft 32. The bearing 79 is provided on a curved spring 80 attached to a lid 81 at an end of the bushing 82 far away from the clean room 49. The bushing 82 contains the bearing 33, similar to the bushing 34 of the embodiment shown in FIGS.
Are integrally connected to an assembling flange 83 corresponding to.

The thrust bearing 79 is preferably conductive, like a curved spring. By doing so, the electrostatic charging of the shaft 32 can be discharged through the bearing 79 and the curved spring 80.

The printed board 38 is provided with a groove 85 of the assembly flange 83.
At the assembly flange 83 by a layer of adhesive 84 at To further reduce the axial height of the disk drive, the printed circuit board 38 is provided with a through hole 86 in the area of the rotational position sensor, the rotational position sensor penetrating into the groove 85 and the through hole 86. At the point of contact between the upper pole piece 73 and the inner peripheral wall 87 of the bushing 82, an additional packing, indicated by the reference 88 by a coating varnish or the like, is provided.

Embodiment 4 The embodiment shown in FIG. 5 is very similar to the embodiment shown in FIG. In this case, the difference is that the bearing bush 31 is formed integrally with the end face wall 17A of the outer rotor cup 17 which acts as a magnetic shield. The end face wall 17A has 3 deviated 120 ° from each other in the circumferential direction.
Each screw hole 90 is provided. This screw hole 90 is used for mounting a fixing device (not shown) for the fixed storage disk 39 (FIG. 2), and can receive a corresponding mounting screw (mounting means). Under the end wall 17A, there is a cover ring 91 that seals the internal space of the motor with respect to the clean room 49 at the screw hole 90. Also in this case, the space 46 surrounded by the disk support portion 36 'of the same boss 37' as in the case of FIG.
There is a stator portion and a rotor portion of the drive motor that act magnetically over most of the axial length therein. Further, a groove 47a having a substantially circular cross-section is provided near the corner of the outer peripheral surface of the cylindrical boss 37 'of the disk support portion 36' at the inner end of the flange surface of the flange portion 47 at a position surrounding the corner in the circumferential direction. Is formed.

Embodiment 5 FIG. 6 shows another modified embodiment of the present invention, which comprises an outer rotor cup.
Low remanence (soft magnetic) magnetic circuit ring member instead of 17
The present embodiment is basically different from the above-described structure in that a 94 and another shield ring 95 having the same low remanence are provided. The shielding ring 95 extends radially inward from an axial end of the magnetic circuit ring member 94 on the clean room side. Shielding ring 95
Can be considerably thinner than the wall thickness of the magnetic circuit ring member 94. A screw hole 97 functionally corresponding to the screw hole 90 of FIG. 5 is provided in the end wall 90 of the boss 99 formed integrally with the bearing bush 100 of the shaft 32.

The shielding ring 95 has a recess at the screw hole 97 so that the entire length of the screw can act on the screw hole 97.
It has 101. The filler 70 includes an upper end of the motor magnet 13 in FIG. 6, an end 96 of the magnetic circuit ring member 94,
The area between the shielding ring 95 and the radially outer portion is filled. The magnetically acting rotor and stator portions occupy more than two-thirds of the space surrounded by the cylindrical disk support 102 of the boss 99.

In the case of the magnetic circuit ring member 94, this can be a rolled ring, in particular a steel ring or tube section. This manufacture is simplified compared to the use of the outer rotor cup 17. In addition, on the one hand, the wall thickness of the shielding ring 95 can be reduced, and on the other hand, when the outer rotor cup 17 is used, the inevitable radius r at the transition point between the peripheral wall 17B and the end wall 17A (FIG. Additional axial length is saved because there is no space to require 5). The axial space that can be used is the end wall 98
Can be used to make the screw hole 97 thicker, and thus increase the length of the screw hole 97.

(Embodiment 6) In the embodiment shown in FIGS. 1 to 6, the shaft 32 rotates during operation.
Shows an embodiment having a fixed shaft.

The fixed shaft 105 shown in FIG. 7 is attached to a disk storage device, not shown in detail. Axis 105
A boss 107 is rotatably supported by a first ball bearing 106. The boss 107 has an end wall 108 having a bearing bush 109 formed integrally, a disk support 110,
A reinforcing flange 111 protruding radially outward on a side far from the end wall 108 is provided. Boss 107
The magnetic circuit ring member 94 having low remanence is coupled. A shield ring 95 having low remanence is in contact with the inside of the end wall 108.

A printed circuit board 38 with a rotational position sensor, of which only the sensor 42 is shown in FIG. 7, is suspended in this case by the struts 112 (FIG. 8) on the stator laminate 10. A motor cover 114 for sealing the motor at an axial end far from the end wall 108 is supported on the fixed shaft 105 by a second ball bearing 113. Axially outside the bearings 106, 113 are ferrofluid seals 72 and 72 'of the type described in detail with reference to FIG. Magnetic fluid seal 72,
72 'is adapted to seal the bearing device against the clean room 49, in which case the entire drive motor can be placed in the clean room. Stator winding and / or printed circuit board 38
The terminals of the electronic components mounted on the shaft 105 can be pulled out by means of a cable indicated by reference numeral 115, which is housed in an axial groove 116 of the shaft 105.

The embodiment shown in FIG. 8 is basically different from the embodiment shown in FIG. 7 in that the magnetic circuit ring member 94 and the shielding ring 95 are replaced with a low remanence corresponding to the outer rotor cup 17. An integral cup 117 of material is attached to the end wall 117
A and the peripheral wall 117B.

For the two embodiments of FIGS. 7 and 8,
The magnetically acting stator and rotor portions of the drive motor are in a space surrounded by the disk support 110.

[0048]

As described above, according to the disk drive of the present invention, the occupied space is reduced, and the axial dimension is further reduced, and the sealing performance with respect to the clean room without increasing the axial dimension. And simplification of the assembling or manufacturing process can be achieved.

That is, the disk can be easily mounted on the disk support member through the plurality of openings (particularly with screws) via the fixing device, and the inner space of the motor can be easily removed from the clean room by the shielding ring. Sealable and easy to assemble.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view showing another embodiment of the apparatus of the present invention shown in FIG. 2;

FIG. 4 is an axial sectional view showing a preferred embodiment of the present invention.

FIG. 5 is an axial sectional view showing still another embodiment of the present invention.

FIG. 6 is an axial sectional view showing still another embodiment of the present invention.

FIG. 7 is an axial sectional view showing still another embodiment of the present invention.

FIG. 8 is an axial sectional view showing still another embodiment of the present invention.

[Explanation of symbols]

 10: stator laminate 10A: rotating shaft 11A to 11F: stator poles 12A to 12F: magnetic pole piece 13: electric motor magnet 17: magnetic circuit member (outer rotor cup) 17B: peripheral wall 18: drive motor 19: stator 20A Or 20F ... stator groove 21 to 26 ... stator winding 31 ... bearing bush 32 ... shaft 33 ... bearing 36, 36 '... disk support 37, 37' ... boss 38 ... printed circuit board 39 ... storage disk 42, 43, 44… Rotation position sensor device 45… Control magnet 47… Flange part (outer edge part) 49… Clean room 64… Boss 65… Bearing bush 66… Disk support part 72, 72 ′… Magnetic fluid seal 94… Magnetic circuit ring member 95… Shielding ring 99 ... Boss 100 ... Bearing bush 102 ... Disc support 105 ... Fixed shaft 106 ... Bearing 107 ... Boss 110 ... Disc support 113 ... Bearing 115 ... Wire 117 ... Back cover 117B ... Peripheral wall

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Johan von der Heide, Germany 7730 Schramberg, Marktstrasse 15

Claims (17)

[Claims] 1. A housing defining a clean room in a sealed manner, at least one storage disk disposed in the clean room for rotation about an axis and having a central hole, and substantially inside the clean room. And a non-collector DC motor mounted on the DC motor, the DC motor comprising a stator having at least six radially extending magnetic pole pieces substantially uniformly distributed about the axis. A stator groove is formed between each of the pole pieces, and the DC motor further includes a stator winding having at least three phases, and a number of coils equal to the number of the pole pieces. ,
One coil is wound around a corresponding one of the pole pieces, and the DC motor further comprises a rotor mounted on the stator to rotate about the axis; The rotor includes a surface on which a permanent magnet ring is mounted, wherein a cylindrical air gap is formed between the pole piece and an adjacent surface of the permanent magnet ring, wherein the rotor includes a cylindrical air gap. A disk support member having a cylindrical portion extending through the center hole, wherein a plurality of openings are substantially uniform on an end surface of the disk support member for mounting the at least one disk on the disk support member. The disk storage device, further comprising: a shielding ring that is formed adjacent to the opening and seals an internal space of the electric motor from the clean room adjacent to the opening. 2. The disk storage device according to claim 1, wherein said DC motor further comprises at least one seal for generally reducing migration of foreign matter from said motor to said cleanroom. 3. The disk storage device according to claim 2, wherein said at least one seal includes at least one seal between said rotor and a fixed portion of said disk storage device. 4. The disk storage device according to claim 2, wherein said at least one seal comprises a magnetic fluid seal. 5. The disk storage device according to claim 1, wherein said permanent magnet ring is magnetized so as to form at least four radially magnetized permanent magnets of alternating polarity. . 6. A method according to claim 1, wherein a pole gap is defined between magnetic poles in each of said permanent magnets, and a circumferential length of each magnetic pole gap is smaller than a circumferential length of a pair of adjacent permanent magnets. 5. Disk storage according to 5. 7. The disk storage device according to claim 5, wherein the magnetization of the permanent magnet in the radial direction changes substantially trapezoidally in the circumferential direction. 8. The disk storage device according to claim 5, wherein said permanent magnet ring comprises a substantially radially oriented permanent magnet material. 9. Each of said pole pieces is substantially T-shaped and comprises a first radial portion having a relatively narrow circumferential length and a second radial portion having a relatively large circumferential length. Wherein the second radial portions of adjacent pole pieces are circumferentially separated from each other by an intermediate gap, the circumferential length of the intermediate gap being the circumferential length of each of the radial portions. 9. The disk storage device according to claim 1, wherein the length of the disk storage device is smaller than the length of the disk storage device. 10. The rotor according to claim 1, wherein said rotor is an external rotor.
10. The disk storage device according to any one of claims 9 to 9. 11. The magnetic recording medium according to claim 1, wherein said coils are arranged on said pole piece as a plurality of sets evenly distributed in a radial direction.
The disk storage device according to any one of claims 10 to 13. 12. The system further comprising a control circuit fixedly disposed with respect to the stator, wherein the plurality of sets of coils are selectively energized to interact with the permanent magnet ring. 12. The disk storage device of claim 11, wherein the rotor is rotated about the axis such that all coils in each of the sets are energized substantially simultaneously when energized. 13. The motor further comprises a magnetically conductive member fixed to the surface of the rotor, the magnetically conductive member reducing at least a part of a flow of magnetic flux from the motor to the clean room. 13. A disk drive as claimed in any preceding claim, including a radial wall portion coaxially surrounding an axial end of the permanent magnet ring to cause the ring. 14. The disk storage device according to claim 13, wherein an outer diameter of said magnetic conduction member is larger than an outer diameter of a cylindrical portion of said disk support member. 15. The disk storage device according to claim 1, wherein said cylindrical portion of said disk support member coaxially surrounds said permanent magnet ring. 16. The disk storage device according to claim 14, wherein said shielding ring is integrally formed as a part of said disk support member, and said opening is a screw hole. 17. The disk of claim 16, wherein the rotor further includes a disk support outer edge integrally formed as part of the disk support member and extending radially away from the disk support member. The support outer edge has a surface substantially orthogonal to the axis, the surface of which has a radial surface of the at least one disk mounted on the surface of the disk support outer edge. The disk storage device according to any one of claims 1 to 16, wherein a groove is formed at a position close to and surrounding the corner of the circumferential surface in the circumferential direction.