JP3049007B2 - Drive motor for disk storage device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator having a winding,
With a substantially cylindrical gap between the rotor and the rotor
Rotor with a permanent magnet motor magnet arranged coaxially with the rotor,
Motor with a soft magnetic yoke (especially
Motive) and non-rotatably coupled with the yoke concentrically with the yoke
At least one storage disk provided in a clean room
Data that can be inserted into the center hole of the storage disk to accommodate
For disk storage device with boss with disk support
It relates to a drive motor. 2. Description of the Related Art Known disk storage devices of this type (Western
FIG. 3 and FIG.
4) and a boss for storing the storage disk.
And a relatively strong member that supports the disk
With a bearing frame extending in the axial direction in the area of
Turned by press-fitted or cast bearing bushes
Magnetically acting stator part, which is non-rotatably connected to the shaft
And rotor parts, ie stator windings and co-operation therewith
Remove a small part of the axial dimension of the motor magnet
Cover with the support. [0003] The field of disk storage devices
In such cases, the demand for reducing the occupied space of the storage device increases.
I have. Accordingly, the basic object of the present invention is to
Disk storage with less space, especially in the axial direction
The size of the disk is minimized and the effective arrangement of the storage disk
・ Provide a drive motor for disk storage devices suitable for holding
It is to be. [0005] This object is achieved by the present invention.
It is achieved by the following drive motor for storage device
You. The drive motor for a disk storage device includes: (a) a substantially cylindrical shape between a stator having a winding and a stator;
Is arranged coaxially with the stator with a gap
And a rotor having a soft magnetic yoke.
(B) a boss disposed concentrically with the yoke;
Is coupled to the rotor for rotation with the rotor; (c) the boss receives at least one storage disk plate
Cylindrical shape that can be inserted through the center hole of the storage disk
Disk having a disk-shaped outer peripheral surface
(D) the rotor is along an axis of the stator and the rotor.
With or relative to the shaft extending
(E) the boss is radially attached to an outer end remote from its end wall;
An outwardly projecting boss flange; and (f) the motor is radially extended. Do Bottom cover play
(G) the bottom cover plate includes a boss flange.
A recess is housed inside to reduce the axial dimension of the motor.
(H) the top surface of the boss flange is provided with the bottom cover plate.
Located near the upper surface of the upper surface of the sheet.
You. In the case of this structure, the magnetically acting part of the drive motor
Minutes of the storage disk, especially the magnetic hard disk or its
Other types of storage disks, such as optical storage disks
Inside the cylindrical disk support of the boss which is absolutely necessary for holding
Although this space can be largely accommodated,
Give the premise. The scope of protection of the present invention is defined by the main claims.
1 and the description of each dependent claim
The present invention is limited to the embodiment.
Not something. Preferred embodiments and effects of the present invention
Aspects are as set forth in the respective dependent claims, with reference to
To supplement the description, but is further outlined below
You. Stator winding and motor magnet cooperating therewith
The stone is placed inside the space surrounded by the disc support
Preferably, it is provided. Magnetically acting stator part
The minute and rotor parts are almost completely inside this space
In some cases, the overall structure, especially with reduced axial space,
can get. The top of the boss flange is the bottom cover plate
Near the top of the top surface of the (mounting flange) (just above
Position), that is, at the minimum position.
To reduce the axial dimension of the entire disk storage device
As well as being suitable for the effective placement of storage disks.
Become That is, the storage disk is directly placed on the boss flange.
Can be installed to clean as many storage disks as possible
It can be effectively installed in a limited space in a small space.
2). A storage disk such as a magnetic hard disk
The diameter of the center hole is standardized and its size is constant
Is limited to On the other hand, the generation of driving energy
Raw production requires some motor dimensions. For example
Known small storage disks with a central hole diameter of only 25 mm
In some cases, the relationship is particularly critical. Memory with limited diameter
Magnetically acting electric motor
In order to prepare as many places as possible for the machine part,
In a development of the invention, the mechanical strength is taken into account.
Make the wall thickness of the boss disk support as thin as possible
I have. In that case, the wall thickness of the disk support
Equal to the wall thickness of the part concentric with the disk support of the member
Or smaller. [0008] Further, a predetermined straightness of the center hole of the storage disk is determined.
Diameter and the boss relative to the magnetically acting motor part
To provide the maximum cross-section, taking into account the required mechanical strength
The disk support is a cylindrical outer peripheral surface
That is, a peripheral surface without a known bearing frame or bearing rib is provided.
Is preferably obtained. At least the surface of the boss in the clean room is
Prolonged use of disk storage, for example, oxidizing
Discharges dust into the clean room completely or practically
Not be. Boss is machined after machining such as cutting and grinding.
Material that is also suitable for clean rooms,
The storage disk can be collected without performing post-corrosion post-processing.
Strictness required in case of storage disk in clean room
It is preferable that the material be made of a material that conforms to clean conditions. Bo
The boss is driven by this configuration
After assembling with the machine,
Super-finishing the outer surface of the disk support, eg grinding or turning
Can be processed. This is a magnetic disk storage device, especially a hard disk drive.
Drives such as hard disks increase track density
To guarantee the extremely high machine accuracy required for
It is effective for During rotation, the boss surface
Deviation from the theoretical value of the degree, the difference of the radial displacement of the boss surface
The maximum value is called TIR (Total Indicated Run-out)
For example, about 5-15 μm, the boss surface during rotation
Of the displacement during operation against the average value of the radial displacement of
The deviation is usually called non-repetitive runout, and the minimum deviation is
0.2-0.5 μm (manufacturers
Value guaranteed). Furthermore, the cylindrical part of the boss disk support part
Has a radial accuracy of about 5-30 μm,
The flatness of the surface of the part is preferably about 1 μm or less. Concentric rotation of boss in case of disk storage device
Or meet strong demands for minimizing vibration
Therefore, such precision machining of the assembled boss is often performed.
is necessary. Light metals, especially aluminum or aluminum
It has been found that a boss made of a chromium alloy is particularly effective.
Light metal bosses can be cleaned without post-processing after machining.
Maintain suitability for the clean room. This is, for example,
Turning tools while maintaining the required precision.
This can be done with a disk with a cylindrical outer surface.
In the case of a metal support, it is particularly more economical than polishing. boss
Is extruded or cast, magnetic circuit member (yoke)
It is preferable to be thermocompression-bonded. However, in principle
Other possibilities for coupling the boss and yoke include, for example,
For example, it is conceivable to bond these members to each other. The magnetic circuit member is encased in a manner known per se.
It can be formed in a top shape. Especially annular magnetic circuit
Material, in which case the annular magnetic circuit member
Magnet extending radially inward from the axial end of the clean room
A shielding ring is properly fitted into the boss. in this way
To store the necessary induction and drive motors for the magnetic flux
An effective magnetic shielding of the disk is obtained. Magnetic circuit phosphorus
The combination of the ring member and the shielding ring is economical in a cup shape.
Can be manufactured. The shielding ring should be relatively thin
This further increases the overall axial length of the drive.
If this total length is the same, the boss, magnetic
Closing the component group consisting of circuit members and motor magnets
Use a lot of space for the end wall of the boss at the end
Can be Magnetic circuit members are made of rolling rings, especially steel
Rationally or as a tube part
Can be. The rotor and the boss are at least partially driven.
Supported by a bearing device installed in the stator of the dynamic motor
It can be fixedly connected to the shaft. In that case, adjust the axis
The bearing bush to be
In this case, it is formed integrally with the magnetic circuit member (yoke).
Or, in particular, it can be formed integrally with the boss. Subordinate
Thus, no special components for the bush are required.
However, rotors and bosses are a modified development
Is rotatably supported on a fixed shaft via a bearing device
In this case, the stator winding conductors
Through the outside of the drive. The rectified signal and possibly additional control
Control signal, for example a signal for a given reference position of the rotor
A stationary magnetic field sensing rotary position sensor
In the form of a control magnet ring that cooperates with the sensor device
Type control magnet is combined with a unit consisting of a rotor and a boss.
Reasonably combined. In that case, the control magnet is connected to the rotor
Provided on the axially open side of the unit consisting of the boss
Preferably. The control magnet is axially aligned with the motor magnet.
Can be lined up. In some cases, the motor magnet itself
Can also be used as a control magnet. Rotation position sensor
The device is located in the axial direction of the unit consisting of the rotor and the boss.
Installed on the printed circuit board facing the open side in the axial direction
Preferably. Note that the embodiments described in the claims are attached.
Reference numbers are for ease of understanding and must be
It is not intended to limit the invention to the illustrated one. Now, the present invention will be described in further detail with reference to preferred embodiments.
This will be described in detail. It should be noted that the invention described in claim 1 of the claims
The subject of the present invention mainly corresponds to the embodiment of Example 4 below.
However, other embodiments are also cooperated for understanding the invention.
Referred to as (Embodiment 1) In FIG. 1 and FIG.
The dynamic motor comprises a stator 19 with a stator laminate 10.
You. The stator laminated plate 10 has a radiation pair with respect to the center rotation axis 10A.
And has an annular central portion 10B. Stator lamination
The plate 10 forms six stator poles 11A to 11F,
Are substantially T-shaped in the plan view shown in FIG.
They are provided at an angular interval of 60 ° from each other. Laminate board
Alternatively, for example, a sintered iron core may be used. The pole pieces 12A to 12F of the stator poles are permanent.
A substantially cylindrical air gap 14 is formed with the magnet 13 of the motor.
I do. The motor magnet 13 is arranged in a circumferential direction as shown in FIG.
It is magnetized radially with four poles, ie the motor magnet 13
An annular motor magnet 13 comprising four parts 13A to 13D
Two magnetic norths alternately inward facing the air gap 14
There are poles and two magnetic south poles 15 and 16. Pole 15,
In the illustrated embodiment, reference numeral 16 denotes a substantially electrical angle of 180 ° (machine).
(Equivalent to 90 ° mechanically). like this
And a substantially rectangular or trapezoidal shape around the space 14
Magnetization is obtained. The motor magnet 13 is a magnetic circuit member (yoke).
Soft magnetic material that acts as and as a magnetic shield
Mounted in an outer rotor cup 17 consisting of
Glued to the cigarette cup. Outer rotor cup 17
And the magnet 13 constitute the outer rotor 30. Outer rotor bracket
The pump 17 has an end wall 17A and a cylindrical peripheral wall 17B.
I have. This is especially true for the motor magnets 13, especially for rubber magnets.
Or a synthetic resin bonded magnet. Integrated
Glue shell-shaped magnet segments instead of
Or otherwise secured thereto. Particularly suitable for magnet rings or magnet segments
Materials used are magnetic materials in synthetic binders, hard ferrous
Mixture of iron and elastomer material, magnetic magnet material or
Is samarium cobalt. In the illustrated embodiment
Means that each pole actually extends to an electrical angle of 180 °,
It can work with narrower poles. Only
In order to obtain high motor output,
The width must be at least 120 electrical degrees. The stator poles 11A to 11F have a total of six
The stator grooves 20A to 20F are divided. Three phases in this groove
Of the stator winding is fitted. In that case, three-phase winding
Are two coils 21, 22;
3, 24 and 25, 26, each of which comprises one
It is wound around stator poles 11A to 11F. As shown in FIG. 1, each phase winding is connected in series.
Two coils are provided on the diametrically opposite sides of each other.
Have been. These coils are not shown, but
Is wound in two rolls. As can be seen from the schematic diagram of FIG.
In addition, the overlap between the coils 21 to 26 is avoided.
I have. In this way, a particularly short coil head 27 (see FIG.
2) is obtained. The groove openings 28A to 28F have an electrical angle of 3
° to 30 ° width. Shape stator winding
When done, the grooves 20A to 20F will be quite full
It is. Generally, the lids for the groove openings 28A through 28F are not necessary.
Absent. The structure of the electric motor shown here is based on a stator groove.
20A to 20F depth can be made relatively small
Therefore, a relatively large stator internal hole 29 is 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. Axial direction of stator core
The ratio of the length L to the stator outer diameter E is equal to or less than 1.
It is preferably smaller than this. This size ratio
Especially important for stable support. Such support
Is especially important when driving disk storage.
You. Moreover, the overall resistance of the stator windings is particularly low.
You. To support the rotor 30, as shown in FIG.
In the center of the outer rotor cup 17, the outer rotor
A short shaft 32 is formed via a bearing bush 31 formed in the cup 17.
Fixed, this short axis is axially spaced from each other
The stator laminate 10 is supported and assembled via the ball bearing 33
Retained in cylindrical bushing 34 fixed to flange 35
Have been. The outer rotor cup 17 is illustrated in FIG.
Not particularly light metal with cylindrical disc support 36
Boss 37 of fixed disk storage device
And is fixed, for example, by shrink fitting. Disk support
The holding unit 36 includes one or several fixed storage disks 39,
A magnetic fixed storage disk is attached to the
The disk support 36 is passed through the center hole 40 of the storage disk 39,
The storage disks 39 are mutually axially oriented by suitable spacers 41
At a distance from the public
It is fixed to the boss 37 by a known fastening means. In the case of the embodiment shown in FIG.
Magnetically acting stator and rotor sections of the
That is, the motor magnet 13 and the stator windings 21 to 26 are
About 2/3 or more of the axial dimension is
Into the space 46 surrounded by the above. Boss 37 De
The wall thickness of the disk support portion 36 is
It is smaller than the cylindrical peripheral wall 17B forming the circuit member,
Motor parts 13, 17, 19 in the well-defined center hole 40
Is prepared for the largest cross section. In particular, disk support
The wall thickness of the part 36 is as small as permissible in terms of mechanical strength
Dimensioned. In order to increase the dimensional stability of the boss 37,
This boss consists of boss 37, outer rotor cup 17 and electric motor
At the open end of the element consisting of magnet 13
Acts to support the adjacent fixed storage disk 39 in the axial direction.
You. Supports a thick flange 47 projecting outward in the radial direction
are doing. The boss 37 has a storage disk supported thereon.
Although not shown in detail, together with the
To the housing of the disk storage device by known methods
Therefore, it is located inside the clean room 49 partitioned. In that case,
The upright flange 35 is one of the boundaries of the clean room with respect to the lower side of FIG.
Forming part. The upper bearing 33 in FIG.
Between the shoulder 51 of the thing 34 and the spacer ring 52,
The side of bearing 52 opposite bearing 33 is located under bearing bush 31.
In contact. The short axis 32 has a lower end formed in a spherical shape.
And is preferably supported by a thrust bearing (not shown).
I have. Retaining ring 55 in annular groove 54 of shaft 32 near lower end 53
Are provided, and two spring washers 56 support the upper side thereof.
You. The spring washer 56 is in contact with the intermediate ring 57. Of the lower
The ball bearing 33 has an intermediate ring 57 and another shoulder 58 of the bushing 34.
Between. The assembly flange 35 may be a rectifier
Slave device and / or other turns, for example for adjusting the speed
A printed circuit board 38 on which circuit elements can be provided.
You. The printed circuit board 38 includes, in particular, three rotational position sensors 4.
2, 43 and 44 are provided, and this sensor is used in the illustrated embodiment.
For example, Hall generators, magnetic resistance plates, magnetic diodes
And a magnetic field sensor such as a magnetic field sensor. Especially integration of bistable connection holes
Circuits are preferred. Rotor poles 15 and 16 with electrical angle of 180 °
To control the position sensors 42, 43, and 44.
The motor magnet 13 can be used directly as the control magnet.
Wear. In the case of the embodiment shown in FIG.
42, 43, and 44 are axially opposed to the magnet 13 that controls this.
ing. However, for example, a rotational position sensor
As shown by the dashed line in FIG.
It can be provided to face the magnet 13 to be controlled in the radial direction.
Wear. Rotational position sensors 42, 43, 44 are connected
Changes at about the same time as the zero crossing point of the corresponding coil voltage.
As is done, the coils 21 to 26 in the circumferential direction
It is provided in the correct position. This is the embodiment shown in FIG.
, The rotational position sensor is connected to the groove openings 28A, 28B and
By deviating by 15 ° mechanical angle from the center of 28C
Is achieved. (Embodiment 2) In the embodiment shown in FIG. 3, the rotational position sensors 42, 43 and 44 are controlled.
A control magnet 45 separate from the motor magnet 13 is provided for control.
This is different from the embodiment shown in FIG. control
The magnet 45 is provided at the open end of the outer rotor cup 17.
Flange 17 protruding radially outward from the peripheral wall 17B
C, on the outside of the motor magnet 13 in the radial direction,
Have been killed. Outer rotor cup 17 and boss 37 '
In the embodiment shown in FIG.
It has just ended. One of the cores at the connection point of the printed circuit board 38
The terminals of the coils 21, 26 are schematically indicated by the reference 59.
I have. From the printed circuit board 38, the connection cable 60 is
It is drawn out through a through hole 61 of the flange 35. (Embodiment 3) FIG. 4 shows another embodiment of the disk storage device.
Here, unlike the configuration shown in FIG. 2 and FIG.
A boss 64 corresponding to the boss 37 is provided on the outer rotor cup 17.
The bearing bush 65 of the shaft 32 is adjacent to the end wall 17A of
It has a formed end wall 64A. From the end surface 64A of the disk support 66 of the boss 64
At the far end, a boss hula that is bent radially outwards
There is a flange 67, and this boss flange 67
66, which is concentric with the disk support 66
It transitions to a peripheral wall 68 having a diameter. Outer wall 68 is radially outward
In the section, the flange 17C of the outer rotor cup 17 (yoke)
Flange). The upper surface of the boss flange 67
Bottom cover plate (assembly flange or motor support
(Housing member) 83
The boss flange 67 is located in the recess of the bottom cover plate 83.
Substantially contained. Outside the peripheral wall 68 of the boss flange 67
The peripheral surface is in contact with the inner wall surface of the recess of the bottom cover plate
They cooperate to form a void (seal). The joint between the flange 17C and the peripheral wall 68 is
By varnish, glue, etc. as shown by joint 69
Sealed. By doing so, the FIG.
As in the case, dust is radiated outward from the flange 17C.
It is prevented from being released and entering the clean room. Rotation
Position sensor (of which only sensor 42 is shown in FIG. 4)
Control magnet 45, which cooperates with the motor magnet 13,
Side arranged in the axial direction and far from the end face 17A of the magnet 13
It is provided in. 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 the magnet 13 facing this end wall
The gap is filled with glue or other filler
ing. The bearing device of the shaft 32 composed of two ball bearings 33
To the motor interior space and clean room
Sealed against. The magnetic fluid seal 72 includes two annular magnetic pole pieces 7.
3, 74, and the permanent magnet rest between these two pole pieces
Between the magnet ring 75 and a part 77 of the shaft 32.
And a magnetic fluid (not shown). this
The format seal is “Ferrofluidic Sea”
The seal 72 is a dust bearing.
Especially effectively prevented from being released into the clean room 49 from the storage
I do. This seal 72 is adjacent to the bearing bush 65 but is
It is provided at intervals in the direction. Do this
And the magnetic fluid is sealed by capillary action.
Is prevented from being pulled out. As can be seen from FIG. 4, the magnetically acting solid
The stator and rotor parts are almost completely
It is provided inside the space 46 surrounded by the holding portion 66. Further
FIG. 4 shows a thrust bearing of the shaft 32. This axis
The catch 79 is located at the end of the bushing 82 far away from the clean room 49.
It is provided on a curved spring 80 attached to the lid 81. Boo
Thing 82 is a bushing of the embodiment shown in FIGS.
The bearing 33 is housed in the same way as the
Are integrally connected to an assembling flange 83 corresponding to. The thrust bearing 79 is electrically conductive like a curved spring.
It is preferable that it is a property. By doing this,
To charge the shaft 32 electrostatically.
Can be discharged. The printed board 38 is provided with a groove 85 of the assembly flange 83.
Bonded to the assembly flange 83 by a layer of adhesive 84 located at
ing. Reducing the axial height of disk storage devices
Therefore, the printed circuit board 38 is out of the range of the rotational position sensor.
The rotation position sensor has a groove 85 and a through hole 86.
I'm stuck inside. The upper pole piece 73 and bushing 82
The contact area between the inner peripheral wall 87 and the coating
Additional packing indicated by reference 88 by varnish etc.
Is provided. Embodiment 4 The embodiment shown in FIG. 5 is significantly similar to the embodiment shown in FIG.
You. In this case, the bearing bush 31 acts as a magnetic shield.
Integrated with the end wall 17A of the outer rotor cup 17
Is different. In the end wall 17A, around
Three screw holes 90 that are offset 120 ° from each other
You. The screw hole 90 is provided for the fixed storage disk 39 (FIG. 2).
Used for mounting a fixing device not shown. End face
Under the wall 17A, a space inside the motor at the screw hole 90 is provided.
There is a cover ring 91 that seals the space between the clean room 49.
Also in this case, the same disk support portion of the boss 37 'as in FIG.
Most of the axial length in the space 46 surrounded by 36 '
The stator part of the drive motor that acts magnetically over
And the rotor part. Embodiment 5 FIG. 6 shows another modified embodiment of the present invention.
This replaces the outer rotor cup 17 with a low remanence
Magnetic circuit ring member 94 and another similar low remanence
And the above-mentioned structure is basically
Is different. The shielding ring 95 is a magnetic circuit ring member
Extending radially inward from the axial end of the 94 clean room side
I have. The wall thickness of the shielding ring 95 is determined by the magnetic circuit ring member 94.
Can be significantly thinner than the wall thickness. Functionally diagram
The screw hole 97 corresponding to the screw hole 90 of No. 5 is
Provided on the end face wall 90 of the boss 99 integrally formed with the
Have been. The shield ring 95 is provided with a screw
Recess 101 capable of creating the entire screw length of hole 97
It has. The filler 70 is provided by the motor magnet 13 shown in FIG.
Of the magnetic circuit ring member 94 and the shielding rib.
Is filled in the area between the radial outer part of the ring 95
I have. Magnetically acting rotor and stator parts
Is the space surrounded by the cylindrical disk support 102 of the boss 99
Account for more than two-thirds of the total. In the case of the magnetic circuit ring member 94, this is rolled.
Ring, especially steel ring or tube part can be
You. This production is simpler than using an outer rotor cup 17
Be transformed into In addition, on the other hand, the wall thickness of the shielding ring 95
On the other hand, the outer rotor
When using the step 17, the transfer between the peripheral wall 17B and the end face wall 17A is performed.
It requires an inevitable radius γ (Figure 5) at the line
No additional space, saving additional axial length
Is done. The axial space that can be used is the end wall 98
To increase the thickness of the screw hole 97 and thus increase the length of the screw hole 97.
Can also be used. (Embodiment 6) In the case of the embodiment shown in FIGS.
7 and 8 show an embodiment with a fixed shaft.
Is shown. The fixed shaft 105 shown in FIG. 7 is illustrated in detail.
Not attached to disk storage. Axis 105
Boss 107 is rotatably supported by the first ball bearing 106
Have been. The boss 107 is formed with a bearing
An end wall 108 with a shoe 109, a disk support 110,
Radially outward on the side far from the end wall 108
And a protruding reinforcing flange 111. Boss 107
The magnetic circuit ring member 94 having low remanence is coupled. end
A low remanence shielding ring 95 is in contact with the inside of the face wall 108.
I have. FIG. 7 shows only the sensor 42.
A printed circuit board 38 with a rotational position sensor is used in this case.
Is suspended from the stator laminate 10 by a support 112 (FIG. 8).
ing. The fixed shaft 105 has an axial direction far away from the end wall 108.
A motor lid 114 for sealing the motor at the
It is supported by a two-ball bearing 113. Bearings 106, 113
On the outside, a magnetic fluid of the type described in detail with reference to FIG.
There are seals 72 and 72 '. Magnetic fluid seal 72, 72 '
Is designed to seal the bearing device against the clean room 49
In that case, the entire drive motor can be placed in a clean room.
it can. Install on stator windings and / or PCB 38
The terminals of the attached electronic components are indicated by reference numeral 115.
Cable that can be pulled out.
The bull is placed in an axial groove 116 of the shaft 105. The embodiment shown in FIG. 8 corresponds to the embodiment shown in FIG.
The fundamental difference from the magnetic circuit ring member 94 and
Instead of shielding ring 95, corresponds to outer rotor cup 17
An integrated cup 117 made of low remanence material
A and the peripheral wall 117B. For the two embodiments of FIGS. 7 and 8,
Magnetically acting stator part and rotor of drive motor
The part is in the space surrounded by the disc support 110
It is in. As described above, the disk of the present invention
According to the drive motor for the storage device, the occupied space is reduced,
The axial dimension is further reduced, and the axial dimension is further increased.
Space-saving and effective storage and
To minimize the axial dimension of the entire storage device
can do. According to the present invention, the disk support of the boss is also provided.
The outer peripheral surface of the holding part can be super finished after assembling the boss and the motor,
Magnetic with low placement of storage disk on top of boss flange
Stricter with increasing track density of disk storage
Can meet the demands of machine accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing one embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. 2 and FIG.
3, 7 and 8 are stored inside the recess of the cover plate
It is not an example showing a boss flange that has been
It is referred to as showing a specific example of the configuration. 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. [Description of Signs] 10 ... Stator laminated plate 10A ... Rotating shafts 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 ... stators 20A to 20F ... stator grooves 21 to 26 ... stator windings 31 ... bearing bushes 32 ... shafts 33 ... bearings 36 and 36 '... disk support parts 37 and 37' ... bosses 38 ... printed circuit boards 39 ... storage Disks 42, 43, 44 Rotational position sensor 45 Control magnet 49 Clean room 64 Boss 65 Bearing bush 66 Disk support 72, 72 'Magnetic fluid seal 94 Magnetic circuit ring member 95 Shield ring 99 Boss 100 bearing bush 102 disk support 105 fixed shaft 106 bearing 107 boss 110 disk support 113 bearing 115 conductor 117 magnetic circuit member (outer rotor cup) 117B peripheral wall

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Johan von der Heide, Marktstraße, 7730 Schramberg, Germany 15 (56) References JP-A-57-53876 (JP, A) JP-A-56 JP-A-166760 (JP, A) JP-A-56-107364 (JP, A) JP-A-58-22571 (JP, A) JP-A-52-54404 (JP, A) JP-A-59-165283 (JP, A) ) Actually open 59-1190 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 19/20

Claims (1)

(57) [Claims] (A) A rotor having permanent magnets and a soft magnet yoke, which is arranged coaxially with the stator with a substantially cylindrical gap formed between the stator having windings and the stator. And (b) a boss disposed concentrically with the yoke, the boss being coupled to the rotor so as to rotate with the rotor, and (c) the boss comprising at least one boss. A disk support portion having a cylindrical outer peripheral surface that can be inserted into the central opening of the storage disk plate to receive the storage disk plate of (a). Being rotatable with or relative to a shaft extending along the axis of the stator and rotor, (e) the boss being radially outward at an outer end remote from its end wall; A protruding boss flange, and (f) Recess electric motor is to include a bottom cover plate for spreading radially as support housing member electric motor, (g) the bottom cover plate, to shorten the axial dimension of the electric motor and accommodates the boss flange inside (H) a drive motor for a disk storage device, wherein an upper surface of the boss flange is disposed at a position above and near an upper surface of the bottom cover plate. 2. 2. The drive of claim 1 wherein said boss is cup-shaped with a substantially cylindrical peripheral wall and includes only a cylindrical disk support having said radially projecting flange at an outer end thereof. Electric motor. 3. 3. The drive motor according to claim 1, wherein a bearing bush is formed on the end wall of the cup-shaped boss. 4. 4. The boss according to claim 1, wherein the outer peripheral surface of the disk support portion is super-finished after the assembly of the boss and the drive motor for centering with a rotating shaft. A disk drive motor according to claim 1. 5. The drive motor according to any one of claims 1 to 4, wherein the boss is extruded or cast. 6. The drive motor according to claim 5, wherein the boss is thermocompression-bonded to the yoke. 7. 7. A drive motor according to claim 1, wherein a control magnet is coupled to the device including the rotor and the boss and cooperates with a sensor mounted on a printed circuit board. 8. The drive motor according to claim 7, wherein the printed circuit board is accommodated in a recess of the bottom cover plate. 9. The drive motor according to any one of claims 1 to 8, wherein the rotor is an outer rotor. 10. The drive motor according to claim 1, wherein the bottom cover plate is formed as an assembly flange. 11. The shaft is a bearing tube or slot in which the bearing is housed.
Extending through the bottom cover plate radially
The inner end is fixed to or integral with the bearing tube or sleeve
The method according to any one of claims 1 to 10, wherein
The drive motor according to claim 1.