GB2092834A - Driving Mechanism for Magnetic Disc Drive Unit - Google Patents

Driving Mechanism for Magnetic Disc Drive Unit Download PDF

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Publication number
GB2092834A
GB2092834A GB8136443A GB8136443A GB2092834A GB 2092834 A GB2092834 A GB 2092834A GB 8136443 A GB8136443 A GB 8136443A GB 8136443 A GB8136443 A GB 8136443A GB 2092834 A GB2092834 A GB 2092834A
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GB
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Patent type
Prior art keywords
rotor
magnetic
driving
stator
hub
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Granted
Application number
GB8136443A
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GB2092834B (en )
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ebm-papst St Georgen GmbH and Co KG
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ebm-papst St Georgen GmbH and Co KG
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Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K7/00Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/08Structural association with bearings
    • H02K7/086Structural association with bearings radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B17/00Guiding record carriers not specifically of filamentary or web form, or of supports therefor
    • G11B17/02Details
    • G11B17/038Centering or locking of a plurality of discs in a single cartridge
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B23/00Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus Intermediate mediums; Apparatus or processes specially adapted for their manufacture
    • G11B23/50Reconditioning of record carriers; Cleaning of record carriers; Carrying-off electrostatic charges
    • G11B23/505Reconditioning of record carriers; Cleaning of record carriers; Carrying-off electrostatic charges of disk carriers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K11/00Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/01Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for shielding from electromagnetic fields
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K11/00Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/30Structural association with control circuits or drive circuits
    • H02K11/33Drive circuits, e.g. power electronics
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K29/00Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
    • H02K29/06Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices
    • H02K29/08Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices using magnetic effect devices, e.g. Hall-plates, magneto-resistors
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K5/00Casings; Enclosures; Supports
    • H02K5/04Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/10Casings or enclosures characterised by the shape, form or construction thereof with arrangements for protection from ingress, e.g. of water or fingers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K2211/00Specific aspects not provided for in the other groups of this subclass relating to measuring or protective devices or electric components
    • H02K2211/03Machines characterised by circuit boards, e.g. pcb

Abstract

A driving mechanism 10 for a magnetic "hard disc" memory drive unit with a driving motor 11 having a stator comprising stator lamination 58 and stator winding 29, and a rotor for driving a hub 70 for receiving at least one magnetic disc and located within a first area of the disc drive unit. A magnetic shield 57, 16, 60 is provided between the driving parts producing the magnetic fields and the portion of the area housing the disc to prevent data losses and problems during data input and output. <IMAGE>

Description

SPECIFICATION Driving Mechanism for Magnetic Disc Drive Unit The invention relates to a driving mechanism for magnetic disc memories, particularly so called "hard disc" memories with a driving motor having a stator and a rotor for driving a hub for receiving at least one hard memory disc and located within a first space of the disc memory.

So called "hard" discs are suitable for storing large quantities of data, which can be written to or read out with the aid of a magnetic head arrangement if the disc is rotated with respect to the magnetic head.

In practice, it has been found that occasionally data stored on hard discs are lost and/or problems occur when writing in or reading out the data.

This invention seeks to provide a driving mechanism for hard disc memories preventing data losses and avoiding problems during data input and output.

The invention is based on the finding that the cause of the aforementioned deficiencies can be magnetic fields emanating from the driving arrangement. These problems may be caused not only by high frequency fields, but also by low frequency fields. There can in particular be a demagnetization of the magnetic coating of the hard disc. It has been shown that the magnetic coating can be damaged even with fields above approximately 3 to 5 gauss.

According to the invention, a magnetic shield is provided between the driving parts producing the magnetic fields and the portion of the first space intended for housing the disc. Such a shield makes it possible to prevent or at least considerably reduce leakage of the magnetically active motor part in the vicinity of the disc, so that also the static or low frequency magnetic field is reduced to harmless values in the vicinity of the disc.

Preferably, in the vicinity of the axial end of the magnetically active motor part there is a magnetic shielding zone and adjacent to the other axial end of the motor a ventilation zone which is sealed relative to the first area. Thus, on one side of the driving motor an area which is substantially free from magnetic interference fields is produced, whilst on the other side of said motor a zone is obtained which in the assembled condition is separated from the first area and between which there is a forced turbulence of the ambient air which is desired for cooling purposes.

The driving motor is preferably a brushless direct current external rotor-type motor with a permanent magnetic rotor. In a rotating rotor casing there is advantageously a one-part permanent magnetic ring or a permanent magnetic band with an approximately trapezoidal radial magnetization over the pole pitch which is bent in annular manner. The permanent magnets can be in particular plastic-bound magnets or socalled rubber magnets. Such magnets are made from mixtures of hard ferrites and elastic material, particularly barium ferrite combined with elastomer.

The hub can form part of the rotating rotor casing. In such a way, the magnetic shield is appropriately located within the motor casing, so that the permanent magnet of the external rotor is preferably surrounded in bell-like manner by the magnetic shield, so that no magnetic stray fields can propagate in the direction of the hub and the discs located on the latter. To obtain a magnetic shield which on the one hand requires relatively little shielding material and on the other ensures a particularly effective suppression of the stray fields, the magnetic shield is appropriately partly formed by at least one shielding member rotating with the rotor and partly by at least one fixed shielding member.

The rotor casing can substantially be in the form of a bell, which is open on the face remote from the hub. If in such a case the rotor casing is made from magnetically non-conducting or poorly conducting material, the rotor bell is preferably at least partly lined with magnetic shielding material.

A driving mechanism of the aforementioned type generally comprises a speed control circuit and/or driving electronics, which in the case of a brushless direct current motor, particularly ensures the necessary commutation. If the magnetic shield also comprises a shielding ring connected to the motor stator, this ring can additionally be used for cooling the speed control circuit and/or driving electronics, particularly if semiconductor components are held in thermally conductive contact with the shielding ring.

Instead of constructing the hub as part of the rotor casing, according to a modified embodiment of the invention the rotor casing can be shaped like a bell open towards the hub, a rotor which is concentric to the rotor casing being connected thereto and on whose end remote from said casing is mounted the hub and the open rotor casing end is covered by means of a shielding plate.

On the face remote from the hub, the rotorpreferably carries a fan for forming the ventilation zone. Such a construction is not only particularly simple, but also leaves the circumferential face of the rotor free as a braking surface for a brake which is frequently provided with such driving mechanisms.

The magnetic tracks of hard discs are extremely close to one another. Furthermore, despite the high precision, certain tolerances and eccentricities of the discs, the hub and/or the bearing system for the rotor shaft are unavoidable. As a result, on disassembling the rotor shaft, the alignment between the magnetic head arrangement and the magnetic tracks of the disc is lost. This leads to a loss of the data stored on the disc, so that the disc must be rewritten. In order to avoid such a data loss when parts of the drive, particularly components of the driving electronics or the speed control circuit or the stator winding fail, according to the invention at least certain parts of the stator and/or rotor are detachably connected to the rotor shaft, independently of the connection between said shaft and the hub.This makes it possible to replace defective drive parts without losing the reciprocal alignment between the magnetic head arrangement and the magnetic tracks on the hard disc. To make it unnecessary to obviate the need for entering the highly clean space containing the disc plate during such a replacement, the detachable parts of the stator and/or rotor are preferably accessible from the side of the driving mechanism remote from the hub.

In conformity with a further development of the invention a rotor shaft which is connected with the rotor casing, is mounted in a mounting tube which mounting tube is sealed against the space for housing the hard disc, in order to prevent the transfer of contaminant particles, e.g. oil or grease particles, from the bearing system into the clean space for receiving the hard disc or discs. In this respect magnetic field fluid seals inserted into the mounting tube proved to be particularly effective; such magnetic fluid seals per se are known under the trade names "Ferrofluidic seal" (manufactured by the Ferrofluidics Corporation, Nashua, New Hampshire, U.S.A.) and "Magring Seal" (manufactured by the Senroflo Corporation, Lexington, Massachusetts, U.S.A.).As to further particulars, reference is made to the leaflet "Ferrofluidic Sealing Capabilities" by Ferrofluidic Corporation, 1979, the article "Tonic prevents computer amnesia" by N. C. Persson in Design News. April 18th 1977, the article "Magnetic shaft seal protects optical encoder" by David J.

Bak, in Design News, January 19th 1981 as well as the article "Magnetic-fluid seals" by R. E.

Rosensweig, G. Miskolczy and F. D. Ezekiel in Machine Design, March 28th 1968.

Functional members and/or mounting members, e.g. a magnetic flux conducting ring of a Fluidic seal, preferably may be integrated into the mounting tube, e.g. integrally cast with the latter.

A number of preferred embodiments of this invention will now be described in greater detail with reference to the accompanying drawings, wherein: Fig. 1 is a section through an embodiment of the driving mechanism according to the invention.

Fig. 2 is a section through a modified embodiment.

Fig. 3 is a section through a third embodiment similar to that of Fig. 2.

Fig. 4 is a section through an embodiment which is identical to the embodiment of Fig. 2 with the exception of sealing means being provided in the mounting tube.

Figs. 5 and 6 are sections through further modified embodiments of the invention comprising detachable rotor and stator members.

Fig. 7 is a large scale plan view of one of the cooling plates of the arrangement of Fig. 6.

Fig. 8 is a side view of the coding plate of Fig.

7.

Fig. 9 is a partial plan view of the stator winding core with a diagrammatically indicated rotation position detector in the position for rotation to the right or left.

Fig. 10 is a plan view of the rotation position detector support plate, and Fig. 11 is a side view of another modified embodiment of the driving mechanism.

The driving mechanism 10 illustrated in Fig. 1 has a brush-less direct current motor 11 with a rotor casing 14 fixed to rotor shaft 10 and concentric to the latter. A stator lamination 58 carrying a stator winding 29 forms part of the stator of motor 11. The stator lamination 58 surrounds a ring bearing 44 forming part of a central support 22. Rotor shaft 12 is mounted in ring bearing 44 with the aid of two bearings 48, 48', which are held in place by spaced retaining rings 50. A cup spring 52 bears on the bottom of bearing 48' and a retaining ring 54 located on rotor shaft 12, so that bearings 48, 48' are axially braced relative to one another. Together with an assembly flange 30, mounting tube 44 forms a one-piece die casting. As an alternative, the mounting tube 44 can be force-fitted into a hub joined to flange 30.

Rotor casing 14 not only surrounds the stator lamination 58, whilst forming a cylindrical air gap 1 5, but on the side remote from assembly flange 30 is axially extended, so that hub 70 is obtained.

Hub 70 is used for supporting and driving one or more (not shown) memory discs having a central bore, whose diameter corresponds to the external diameter of hub 70. The discs can be commercial 5+" or 8" discs. The illustrated construction makes it possible to adapt the diameter of driving hub 70 to the central bore of the discs without taking account of the necessary drive power of motor 11 and the resulting most favourable diameter of air gap 15. A printed circuit board is housed in the free space 26 within hub 70. The printed circuit board 20 is constructed in annular manner and is connected to the central support 22. Circuit board 20 carries the drive electonics and a speed control circuit, which includes inter alia a Hall IC 35 serving as a rotation position detector, output stage transistor 61 and a potentiometer 64. The soldered joints of the circuit components of the drive electronics and the speed control circuit, which are preferably produced in one operation, e.g. in a dip soldering process, are indicated at 65. Potentiometer 64 can be used inter alia for setting different operating points or for compensating component tolerances. It can be adjusted by means of a screwdriver via a bore (not shown) in flange 30 and one of the slots in stator plates 58.

A line 31 leading to the printed circuit board 20 is connected to a d.c. voltage source. The side of circuit board 20 carrying the soldered joints 64 faces the base 40 of rotor casing 14.

In this embodiment, rotor casing 14 is made from a magnetically non-conducting or poorly conducting material, e.g an aluminium alloy die casting. A plurality of continuous segments or a one-part permanent magnet 56 is fixed to the inner surface of rotor casing 14 facing stator plate 58. The permanent magnet is preferably made from a mixture of hard ferrite, e.g. barium ferrite and an elastic material and thus forms a so-called rubber magnet. It is trapezoidally or approximately trapezoidally radially magnetized via the pole pitch with a relatively small pole clearance. A magnetic return path ring 57 is located between the rotor casing 14 and the permanent magnet 56. It is fundamentally also possible to make the rotor casing 14 from magnetically conductive material, particularly soft iron, e.g. in the form of a deep drawn part.In such a case, there is no need for the soft iron return path ring 57.

The magnetic return ring 57 is part of a magnetic shield, which also includes a shielding ring 16 and a further shielding ring 60. Shielding ring 16 is inserted between the face of permanent magnet 56 facing hub 70 and a shoulder 17 of rotor casing 14 and rotates together with the latter. However, shielding ring 60 is fixed. It is connected by means of brackets 62 to circuit board 20 and is appropriately additionally fixed by means of fastenings or glued joints 66 to the mounting tube 44 in the vicinity of a collar 68 of the stator or via not shown pins to an end plate 67 of the stator. This prevents oscillating movement of the shielding ring 60.

Return path ring 57 and the two shielding rings 16, 60 surround in bell-like manner the magnetically active part of driving mechanism 10.

This effectively prevents the propagation of magnetic stray fields in the vicinity of the discs located on hub 70. It is not possible for there to be any significant penetration of the stray field through the annular clearance between shielding ring 16, 60 and the recesses of the shielding ring 60 for the passage of the Hall IC 35 or a plurality of such Hall IC's, because the soft magnetic shielding rings attract this field to them. In the represented embodiment, the fixed shielding ring 60 is simultaneously used as a cooling plate for the output stage transistors 61 which are connected in thermally conductive manner to the shielding ring 60 also by a full surface engagement. The cooling members of the output stage transistors 61 can, if necessary, be electrically insulated from shielding ring 60, e.g.

by means of a mica disc or the like. It is also possible to subdivide the shielding ring 60 as a function of the number of output stage transistors 61 in order to obviate such an electrical insulation.

Assembly flange 40 makes it possible to mount driving mechanism 10 in the manner shown in Fig. 1 on a partition 72 of the otherwise not shown disc drive unit. Partition 72 separates the area of maximum cleanness for receiving the discs from the remainder of the interior of the apparatus. Dirt particles, grease vapours or the like which may emanate from bearing 48 consequently also have no prejudical action. The connection to the interior of the motor is provided only by a gap 71 between the rotor casing 14 and assembly flange 30. This gap 71 is relatively long.

In addition, one or more seals may optionally be provided in the vicinity of gap 71.

A fan 32 with fan blades 33 is fixed to the free end of rotor shaft 12 remote from hub 70. Fan 32 brings about an intense movement of the air in the vicinity of assembly flange 30, so that the latter is cooled. By means of mounting tube 44 and flange 30, heat due to energy losses from motor 11 is effectively conducted to the outside.

To prevent electric charging of the rotor bell which is prejudical to the operational reliability of the plate store, rotor shaft 12 is electrically connected to the apparatus shaft by means of a bearing ball 36 and a spring contact (not shown).

The embodiment of Fig. 2 functionally substantially corresponds to that of Fig. 1.

However, diverging from the latter, the rotor casing 74 is shaped like a bell, which opens out towards assembly flange 30. Hub 75, which is separate from rotor casing 74 and serves to receive one or more hard discs, is fixed to the free end of rotor shaft 12. In this embodiment, rotor casing 74 is made from magnetically conductive material and is preferably deep-drawn. It is connected to rotor shaft 12 by hub body 76, which is pressed into the central opening of the rotor bell. The permanent magnet 56 directly engages on the inner wall of rotor casing 74. A printed circuit board 79 and a substantially flat shielding plate 80 are connected to the end plate 67 of the stator by means of brackets 77, 78. In conjunction with rotor casing 74, shielding plate 80 prevents the escape of a magnetic stray field into the space taken up by the hard memory discs.

In the same way as in the case of the embodiment of Fig. 1, the steel ball bearing 48 offers a certain shielding action. Semiconductor components of the driving electronic and/or the speed control circuit which are not shown in Fig 2 can be held in thermally conductive contact with the assembly flange and/or the shielding plate 80 for cooling purposes.

An axially flat radial impeller constructed as an injection moulded part is fixed to the outside of base 81 of rotor bell 74 and in the manner indicated by arrows 83 draws air into the central area and discharges it radially outwards.

In the modified embodiment of Fig. 3, the bellshaped rotor casing 74 is detachably connected to rotor shaft 12. For this purpose, a hub body 85 fixed to rotor shaft 12 has a seat 86 for the rotor bell and an external thread 87. A screw ring 88 can be screwed into the external thread 87 and presses in a detachable manner rotor casing 74 against seat 86 of hub body 85. In an alternative embodiment (not shown), seat 86 can be a conical seat.

After detaching screw ring 88, the rotor casing 74 can be drawn off without there being any modification to the reciprocal alignment between the rotor shaft 12 or a hub corresponding to hub 75 according to Fig. 2 fixed on the free end of said shaft and the magnetic head arrangement of the rigid disc memory. After removing the rotor casing 74, access can be obtained to driving electronics and a speed control circuit located on circuit board 90. If necessary, the printed wiring board 90 can be removed from the stator and replaced. If desired, the arrangement can also be such that stator lamination 58 can be removed from the mounting tube 44 together with stator winding 29.

It is obvious that the above-described embodiments can, if necessary, be modified. For example, it is possible to provide the hub 70 of the arrangement of Fig. 1 with a magnetically shielding lining in the manner indicated by dotted lines at 91. Fig. 3 shows a seal 93 above bearing 48 and its function is to prevent any grease vapours or the like from bearing 48 from passing into the space receiving the discs. A corresponding seal 93 is preferably also provided with the embodiment of Fig. 2. Seal 98 can appropriately be so constructed as a low friction lip seal. In place of this or in addition thereto, bearings 48, 48' can be constfucted as sealed precision bearings.

In the case of a brushless direct current motor 11, it can advantageously be a single-phase electronic motor with an auxiliary reluctance torque (one or two-pulse) (U.S. Patent 3,873,897) or a three-phase electronic motor of the type described in U.S. Patent 4,092,572. The idling speed of motor 111 can be 5,800 r.p.m.

and the rate of speed e.g. 3,600 r.p.m.

Advantageously, the stator has four marked, wound poles, whose pole tips are deformed in such a way that in the vicinity thereof the width of the air gap 15 is modified and consequently the auxiliary reluctance torque is produced.

The embodiment of Fig. 4 is substantially identical to that of Fig. 2. However, in order to seal the bearing system of rotor shaft 12 relative to the space receiving the disc or discs, a magnetic field seal 95 is inserted into the mounting tube 44 in the region between hub 75 and bearing 48. Magnetic fluid seal 95 consists of a pair of pole pieces 96, 97, a permanent magnet ring 98 positioned between the two pole pieces, and a magnetic liquid (not illustrated) which is introduced into an annular gap 99 between the magnet ring 98 and a sleeve 100 fixed to rotor shaft 12. Such a seal is known under the trade name "Ferrofluidic seal". Seal 95 prevents contaminant particles moving from the bearing system into the space receiving the rigid memory discs.

The embodiment of Fig. 5, in a manner similar to the embodiment of Fig. 2, comprises rotor shaft 12 which carries hub 75 at one of its ends, the rotor shaft being rotatably mounted by bearings 48, 48' in mounting tube 44 which merges into mounting flange 30. A shielding ring 101 is fixed to the lower surface of mounting flange 30 in concentric relationship relative to mounting tube 44. Rotor casing 74 and permanent magnet 56 are detachably fixed to rotor shaft 12. For this purpose a screw 102 engages a central threaded bore at the (in Fig. 5) lower end of rotor shaft 12.

The head of screw 102 engages a hub body 103 of rotor casing 74 and urges the hub body against a securing ring 104. The latter is inserting into a circumferential groove of the rotor shaft 12. Cup springs 52 abut the opposite side of ring 104.

Stator lamination 58 is detachably mounted on one end (in Fig. 5 the lower end) of mounting tube 44. Stator lamination 58 is urged against a shoulder 106 of mounting tube 44 by screws 105 which are screwed into the lower end of mounting tube 44. Only one of screws 105 is illustrated in Fig. 5. A body 107 which is connected to the stator lamination 58 carries at its free end (the upper end in Fig. 5) a printed circuit board 108 for the driving electronic unit and/or a speed control circuit.

By loosening screw 102 at first rotor casing 74 together with permanent magnet 56 may be removed from rotor shaft 12. Then, upon loosening of screws 105, the stator lamination 58 carrying stator winding 29, and the printed circuit board 108 likewise may be detached from mounting tube 44. The relative alignment between the magnetic head arrangement of the disc memory and the magnetic tracks of the memory discs mounted on hub 75 is not affected by this.

A sleeve 110 is pressed into the upper end of mounting tube 44 in the region between upper bearing 48 and hub 75. Sleeve 110 carries a permanent magnet ring 111. A magnetic liquid (not illustrated) is introduced into the gap between permanent magnet ring 111 and an extension 112 of hub 75. This magnetic liquid together with magnet ring 111 defines a Magring seal as seal 95 of the embodiment of Fig. 4, prevents the movement of grease or oil particles from the bearing system into the space receiving the hard memory discs.

Sleeve 110 need not be a separate member and may in fact be integrated into mounting tube 44. In the embodiment of Fig. 4 at least the pole piece 97 may be integrally moulded into mounting tube 44.

As follows from Fig. 5, rotor casing 74 in this embodiment does not carry blower blades or the like. In view of the high speed of rotation of rotor casing 74 used in hard memories, nevertheless a considerable ventilation effect is obtained by the rotation of the casing.

In order to further improve the magnetic shielding effect, rotor casing 74, as indicated in Fig. 5 in dotted lines, may protrude beyond permanent magnet 54 and extend into the vicinity of magnetic shielding ring 101.

In much the same way as in the embodiments of Figs. 2 to 5, the embodiment according to Figs.

6 to 9 has a rotor casing 14 made from a good magnetically conducting material and in particular mild steel. Hub 75 is not shown. Slotted supports 114 are shaped onto the upper stator end plate 65 in Fig. 6 and in the case of this embodiment, said supports carry three shielding and cooling plates 60 which are electrically separate.

In turn, the shielding and cooling plates 60 are provided with legs 11 5 for holding circuit carrier 20 constructed in the form of a printed circuit board, with rotation position detectors 35, output stage transistors 61 and further circuitry components, whereof one is indicated at 63. Core 58 carrying the stator winding, circuit carrier 20 and the shielding and cooling plate 60 in this way form a pre-assemblable unit, which can be connected to the remaining motor assemblies as an entirety and which permits a precise reciprocal angular alignment of the stator pole clearances and the rotation position detectors 35.

As can be gathered in detail from Figs. 7 and 8, each of the shielding and cooling plates 60 has two groups of rectangular recesses 11 6, 117.

Each of the plates 60 is held by two supports engaged either in recesses 11 6 or recesses 11 7 as a function of the motor rotation direction. Each of the plates 60 is in good thermally conducting connection with in each case one of the output stage transitors 61 of circuit carrier 20. Openings 11 8 are provided in the shielding and cooling plates 60 for fixing the output stage transistors 61. Plates 60 also contain a guidance opening 11 9, through which is passed one of the rotation position detectors 35, preferably Hall IC's soldered to circuit carrier 20. Rotation position detector 35 is stuck in guidance opening 11 9 in order to ensure a particularly stable seat.Each of the plates 60 is provided with a group of three legs 11 5 stamped from the sheet metal material forming the shielding and cooling plate and are bent upwards at right angles with respect to the plane of the plate. Attachments 120 of legs 11 5 are inserted through corresponding recesses in circuit carrier 20 and are soldered to the latter.

These attachments 120 form shoulders on which rest the circuit carrier 20. Here again, the soldering of attachments 120 appropriately takes place in one operation, e.g. by dip soldering, with the production of the soldered joints between circuit carrier 20 and the circuitry components of the driving electronic and control circuit.

It has proved advantageous in practice to displace the rotation position detector or detectors 35 by a certain lead angle, i.e. by a certain amount counter to the rotation direction with reference to the stator pole clearances in the centre of the stator slot. As a result, the commutating signal is necessarily advanced compared with the induced voltage and consequently the commutated current rise delayed by the winding inductance is compensated. For example, for a rotor rotation direction 122 (Fig. 9) with reference to the slot centre 123 the rotation position detector 35 should have the position indicated at 124.

However, in the case of an opposite rotor rotation direction 125 a corresponding advance is sought by displacing rotation position detector 35 in the opposite direction to point 126 with reference to slot centre 123. This differing alignment of the rotation position detectors with respect to the stator pole clearances as a function of the desired rotation direction is brought about here in a very simple way in that the slotted supports 114 provided with detents 127 can alternatively be engaged in recesses 11 6 or recesses 11 7, which for example have a reciprocal angular distance of 120. Together with recesses 116 or 117, slotted supports 114 form snap connections. If necessary, they can be detached by compressing the legs of the slotted supports until the detents can pass through recesses 116 or 117.

In the embodiment of Fig. 6, for the reasons indicated thereinbefore, rotor casing 14 and winding core 58 are constructed so as to be detachable together with circuit carrier 20. To this end, a hub 128 is connected to rotor casing 14 e.g. by caulking or wedging and is placed on the lower end of rotor shaft 12 in Fig.

6. This end of rotor shaft 12 passes into a reduced diameter external thread portion 129. A standard nut, e.g. a hexagonal nut 130 is screwed onto the threaded portion 129 and by means of washer 131 presses the hub against the retaining ring 54. The end face of threaded portion 129 is rounded and, in conjunction with a not illustrated contact, can be used for eliminating electrostatic charges from shaft 12.

For the detachable fixing of winding core 58 the bottom stator lamination of the e.g. riveted bundle of laminations 59 is formed by a lamination 132 with an internal diameter which is the same or smaller than the internal diameter of mounting tube 44. This lamination 132 engages on the lower end face of mounting tube 44 in Fig.

6. In this area, it is provided with three circumferentially distributed holes 133. Selftapping screws 105 engaging in cored holes 134 of mounting tube 44 project through hole 133.

As a result of the cooperation of screws 105 with holes 133 of stator lamination 132, torsion between mounting tube 44 and winding core 58 is effectively prevented. After removing screws 105, winding core 58 together with the stator winding (not illustrated in Fig. 6), circuit carrier 20 and shielding and cooling plates 60 can be effortlessly removed from mounting tube 44 without a detaching device being required.

Whereas in the embodiment of Fig. 6, the connection between winding core 58 and shielding and cooling plates 60 takes place by means of the support 114 on end plate 67, it is possible for example possible for the rivets 135 (Fig. 9), which are electrically insulated from the stator laminations or which are made from insulating material and serve to hold together the bundle of stator laminations, to project over the end face of winding core 58 of Fig. 6 and then the shielding and cooling plate can be fixed to said projecting rivet ends.

A layer 138 (Fig. 6) made from a soft damping material is inserted between the bundle of stator laminations 59 and that part of the mounting tube 40 which carries the latter. This damping material prevents vibrations and noise resulting therefrom.

If the drive electronics and an optionally provided control circuit are arranged separately from motor 11, in the embodiment of Fig. 6 in place of the shielding and cooling plate 60 carrying the circuit board 20 a carrier plate 150 of the type shown in Fig. 10 can be clipped to three of the slotted supports 114. Plate 140 then only carries the rotation position detectors 35 35 constituted in the present embodiment by three Hall IC's at a reciprocal angular distance of 600. In much the same way as with shielding and cooling plate 60 carrier plate 140 is provided with three groups of rectangular recesses 141, 142, having e.g. a reciprocal angular distance of 120. When supports 114 are engaged either in recesses 141 or in recesses 142, a desired lead angle for one or other motor rotation direction can be set for commutating purposes.In this case, magnetic shielding can, for example, be provided in that in the area between end plate 67 and the bottom of flange 30 a not shown shielding ring is provided.

In the embodiment of Fig. 1 a hub 145 with a cast-in bush 146 is pressed onto the upper end of rotor shaft 12, which is provided with a milled edge 144. The internal diameter of hub 145 is larger by a relatively small amount than the external diameter of mounting tube 44 and, as shown at 147, the inner area of the hub is widened conically in a downward direction. Base 148 of hub 145 is spaced from the upper end plates of mounting tube 44 and this distance is greater than the distance between the inner peripheral wall of the hub from the outer peripheral wall of the mounting tube. A plurality of bores 149, of which only one is shown in Fig.

11, extends parallel to the rotation axis through base 148 of hub 145. It has been found that this construction leads to a particularly effective formation of a desired air flow in the vicinity of the rigid memory discs located on hub 145.

Claims (48)

Claims
1. A driving mechanism for a magnetic disc memory drive unit comprising a driving motor having a stator and a rotor, a hub driven by the rotor for receiving at least one magnetic memory disc, and a magnetic shield between the hub and driving parts of the motor producing a magnetic field.
2. A driving mechanism according to Claim 1, wherein adjacent to one axial end of the said parts of the motor is provided a magnetic shielding area and adjacent to the other axial end of the motor is provided a ventilation zone sealed with respect to the space for the disc.
3. A driving mechanism according to Claim 1 or Claim 2, wherein the driving motor is a brushless direct current motor.
4. A driving mechanism according to any one of the preceding Claims, wherein the rotor is constructed as a permanent magnetic external rotor with an all-round rotor casing and at least one permanent magnet housed in the rotor casing.
5. A driving mechanism according to Claim 4, wherein the hub is part of the rotating rotor casing.
6. A driving mechanism according to Claim 5, wherein at least part of the magnetic shield is housed within the rotor casing.
7. A driving mechanism according to any one of the Claims 4 to 6, wherein the permanent magnet of the external rotor is surrounded in belllike manner by the magnetic shield.
8. A driving mechanism according to any one of the preceding Claims, wherein the magnetic shield is partly formed by at least one shielding member rotating with a rotor and partly by at least one fixed shielding member.
9. A driving mechanism according to any one of Claims 6 to 8, wherein the rotor casing is made from magnetically non-conductive or poorly conductive material, and the permanent magnet is enveloped by a magnetic flux return ring which forms part of the magnetic shielding member and runs substantially radially in the rotor casing.
10. A driving mechanism according to any one of Claims 6 to 9, wherein the rotor casing is substantially shaped like a bell, which is open on the face remote from the hub, and is at least partly lined with magnetic shielding material.
11. A driving mechanism according to Claim 10, wherein a shielding ring rotating with the rotor casing is present between the face of the permanent magnet facing the hub and a shoulder of the rotor casing wall.
12. A driving mechanism according to Claims 8 and 11, wherein the magnetic shield additionally has a shielding ring connected to the motor stator.
13. A driving mechanism according to Claim 12 having semiconductor components at least one of which is held in thermally conductive contact with the fixed shielding ring.
14. A driving mechanism according to Claim 4, wherein the rotor casing is shaped like a bell open towards the hub, a rotor shaft which is concentric to the rotor casing is connected thereto, the hub can be placed on the end thereof remote from the rotor casing and the open end of the rotor casing is covered by means of a shielding plate.
15. A driving mechanism according to Claim 14, wherein the rotor shaft is mounted in a tube bearing concentric thereto, which is connected to a motor assembly flange and the shielding plate is substantially flat and fitted to the assembly flange.
16. A driving mechanism according to Claim 15 having semiconductor components, wherein the assembly flange carries a printed circuit board for the semiconductor components, the shielding plate is positioned adjacent to the printed circuit board and at least one of the semiconductor components is held in firmly conductive contact with the assembly flange and/or with the shielding plate.
17. A driving mechanism according to any one of Claims 14 to 16, wherein the rotor casing is made from magnetically conductive material and itself forms part of the magnetic shield.
18. A driving mechanism according to any one of Claims 2 to 17, wherein on the face remote from the hub, the rotor carries a fan.
19. A driving mechanism according to Claim 1 8 when appendant to any one of Claims 14 to 17, wherein an impeller is fixed to the radially directed outside of the bell-shaped rotor casing.
20. A driving mechanism according to Claim 18 or Claim 19, wherein the fan is constructed as an axially flat radial blower.
21. A driving mechanism according to any one of the preceding Claims, having a rotor shaft forming part of the rotor and mounted in a bearing system, wherein at least a part of the stator and/or rotor is detachably connected to the rotor shaft, independently of the connection between the rotor shaft and the hub.
22. A driving mechanism according to Claim 21, wherein the detachable parts of the stator and/or the rotor are accessible from the side of the driving mechanism remote from the hub.
23. A driving mechanism according to any one of the preceding Claims, wherein the rotor comprises a permanent magnet constituted by a one-part permanent magnetic ring or a permanent magnetic band with an approximately trapezoidal radial magnetization, which ring or band is curved in an annular manner.
24. A driving mechanism according to any one of the preceding Claims, wherein the rotor comprises a permanent magnet including a ferrite, preferably barium ferrite combined with an elastomer.
25. A driving mechanism according to any one of the preceding Claims, wherein a rotor shaft connected to the rotor casing is mounted in a mounting tube, said mounting tube being sealed against the space for housing the memory disc.
26. A driving mechanism according to Claim 25, wherein the mounting tube includes a magnetic fluid seal.
27. A driving mechanism according to Claim 26, wherein functional members and/or mounting members of the magnetic fluid seal are integrated into the mounting tube.
28. A driving mechanism according to Claim 4 and Claim 21 or 22, wherein the rotor casing is detachably connected to the rotor shaft mounted in a mounting tube and the stator lamination is detachably mounted on the mounting tube.
29. A driving mechanism according to Claim 28, wherein a printed circuit board for a driving electronic unit and/or a speed control circuit is connected to the stator lamination and is detachable from the mounting tube together with the stator lamination.
30. A driving mechanism according to Claim 3 and any one of Claims 4 to 29, wherein a circuit carrier is provided for the drive electronics and/or a control circuit, whose output stage transistors are associated with cooling plates electrically separate from one another and the cooling plates are fitted to a stator winding core and in turn support the circuit carrier.
31. A driving mechanism according to Claim 30, wherein the cooling plates are fitted to the stator winding core by means of snap connections.
32. A driving mechanism according to Claim 31, wherein the snap connections are detachably constructed.
33. A driving mechanism according to Claim 31 or 32, wherein the circuit carrier carries one or more position rotation detectors and the snap connections can be randomly engaged in one of at least two differently reciprocal angular alignment positions between the stator winding core and the circuit carrier supported on the cooling plate.
34. A driving mechanism according to any one of Claims 30 to 33, wherein supports projecting from one end face of the winding core are provided for connecting the stator winding core to the cooling plates and said supports can engage in recesses of the cooling plates.
35. A driving mechanism according to Claim 34, wherein the supports are shaped onto a stator end plate.
36. A driving mechanism according to any one of Claims 30 to 35, wherein legs are stamped and bent from the cooling plates for supporting the circuit carrier, said legs also being inserted and soldered in recesses of the circuit carrier.
37. A driving mechanism according to any one of Claims 33 to 36, wherein the position rotation detector or detectors are inserted through guidance openings in the cooling plate.
38. A driving mechanism according to Claim 37, wherein the rotation position detector or detectors are fixed with respect to the guidance openings and are preferably stuck in the said guidance openings.
39. A driving mechanism according to any one of Claims 3 to 12,14, 15 and 17 to 28, with drive electronics arranged separately from the driving motor, wherein a carrier plate for at least one rotation position detector can be provided to a stator winding core by means of supports in alternatively one of at least two different reciprocal angular alignment positions between the winding core and the carrier plate.
40. A driving mechanism according to Claim 28, wherein the bundle of stator laminations has in the vicinity one one end face at least one lamination, whose internal diameter is the same as or smaller than the internal diameter of the mounting tube and is provided with holes through which can be inserted fixing elements cooperating with the mounting tube.
41. A driving mechanism according to any one of Claims 28 to 40, wherein a soft damping material is placed between the bundle of stator laminations and that part of the mounting tube carrying the bundle of stator laminations.
42. A driving mechanism according to any one of the preceding claims, wherein the hub has a central opening widening conically towards the driving motor and air passage openings are formed in the base of the hub for an air flow passing through the central opening.
43. A disc drive unit for a magnetic disc, comprising a space for a magnetic disc, a drive motor having a rotor and a stator, a hub driven by the motor for driving the magnetic disc in the space, and a magnetic shield between the space and driving parts of the motor producing a magnetic field.
44. A driving mechanism for magnetic disc memories with a driving motor having a stator and a rotor for driving a hub for receiving at least one magnetic memory disc and located within a first space of the disc memory, wherein between the driving parts producing the magnetic field and the portion of the first space for housing the memory disc magnetic shields are provided.
45. A unit or mechanism as claimed in Claim 43 or Claim 44, and including the further limitation of any one of Claims 2 to 42.
46. A disc drive unit for a magnetic disc, comprising a space for a magnetic disc,#a drive motor having a stator, a drive shaft, and a rotor mounted on the drive shaft, a hub on the drive shaft for driving the magnetic disc in the space, at least a part of the stator and/or the rotor being capable of being removed from the motor without the necessity of removing the drive shaft and hub assembly, and a magnetic shield being provided between the said space for the magnetic disc and the parts of the motor producing a magnetic field.
47. A unit or mechanism as claimed in any one of the preceding Claims, wherein the magnetic disc is a hard disc.
48. A unit or mechanism for a magnetic disc substantially as hereinbefore described with reference to, and as illustrated by any one of the accompanying drawings.
GB8136443A 1980-12-05 1981-12-03 Driving mechanism for magnetic disc drive unit Expired GB2092834B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE3045972 1980-12-05
DE19813144629 DE3144629C2 (en) 1980-12-05 1981-11-10

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GB2092834A true true GB2092834A (en) 1982-08-18
GB2092834B GB2092834B (en) 1984-12-12

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GB (1) GB2092834B (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0098010A1 (en) * 1982-06-28 1984-01-11 Atasi Corporation Unitary assembly, including spindle mount, transducer actuator support structure and magnetic shielding, for disc drive
EP0098009A1 (en) * 1982-06-28 1984-01-11 Atasi Corporation Memory storage apparatus having improved housing and base plate arrangement
DE3347360A1 (en) * 1983-12-28 1985-07-11 Papst Motoren Gmbh & Co Kg electric motor
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EP0151260A1 (en) * 1984-02-07 1985-08-14 Siemens Aktiengesellschaft Magnetic disc memory comprising a stack of discs with double sided bearing within a partially resilient casing
EP0151258A1 (en) * 1984-02-07 1985-08-14 Siemens Aktiengesellschaft Divided housing with peripheral ring seal for magnetic disc memory
EP0253626A2 (en) * 1986-07-18 1988-01-20 Fujitsu Limited Magnetic disc device
USRE38601E1 (en) 1980-05-10 2004-09-28 Papst Licensing, GmbH & Co. KG Disk storage device having a radial magnetic yoke feature
USRE38662E1 (en) 1980-05-10 2004-11-30 Papst Licensing Gmbh & Co. Kg Disk storage device having a sealed bearing tube
USRE38673E1 (en) 1980-05-10 2004-12-21 Papst Licensing Gmbh & Co. Kg Disk storage device having a hub sealing member feature
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Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE37058E1 (en) 1980-05-10 2001-02-20 Papst Licensing Gmbh & Co. Kg Disk storage device having contamination seals
GB2127231B (en) * 1982-07-27 1987-08-19 Papst Motoren Gmbh & Co Kg Drive motor unit for signal-processing devices especially information-storage-disk devices
JPH0782699B2 (en) * 1984-06-01 1995-09-06 パプスト ライセンシング ゲーエムベーハー Disk drive
DE3546933B4 (en) * 1984-06-01 2005-02-03 Papst Licensing Gmbh & Co. Kg Recording disc drive system - has inside out type DC motor with discs supported on external rotor
JP2544710Y2 (en) * 1987-11-25 1997-08-20 日本電産 株式会社 Spindle motor
JPH04200248A (en) * 1990-11-29 1992-07-21 Mitsubishi Electric Corp Disk drive
US6271988B1 (en) 1997-01-04 2001-08-07 Papst Licensing Gmbh & Co. Kg Disk storage device with improved spindle torque and acceleration
US6344946B1 (en) 1997-04-01 2002-02-05 Papst Licensing Gmbh Disk storage device with improved spindle torque and acceleration
FR3038160A1 (en) * 2015-06-29 2016-12-30 Valeo Systemes Thermiques electric motor of an air drive device and air drive device

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3329845A (en) * 1964-03-16 1967-07-04 Lear Jet Corp Self-shielding motor
DE2143752C3 (en) * 1971-09-01 1980-10-02 Papst-Motoren Kg, 7742 St Georgen
BE791363A (en) * 1971-11-15 1973-05-14 Xerox Corp Devices for thermal compensation unit of a memory disk
US4115715A (en) * 1974-04-08 1978-09-19 Papst-Motoren Kg Brushless d. c. motor
DE7523655U (en) * 1975-05-12 1980-10-09 Papst-Motoren Kg, 7742 St Georgen Motor with a scheibenlaeuferrotor
JPS5125108A (en) * 1974-08-27 1976-03-01 Sony Corp Kaitenhetsudosochi
US4062049A (en) * 1976-04-02 1977-12-06 Burroughs Corporation Integrated Disk File Module and memory storage system
US4101945A (en) * 1976-09-07 1978-07-18 Sycor, Inc. Drive spindle assembly for disc file
DE2944212C2 (en) * 1978-11-03 1994-10-20 Papst-Motoren Gmbh & Co Kg, 7742 St Georgen, De
US4275339A (en) * 1979-12-21 1981-06-23 International Business Machines Corporation Bifilar brushless DC motor

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* Cited by examiner, † Cited by third party
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USRE38673E1 (en) 1980-05-10 2004-12-21 Papst Licensing Gmbh & Co. Kg Disk storage device having a hub sealing member feature
USRE38662E1 (en) 1980-05-10 2004-11-30 Papst Licensing Gmbh & Co. Kg Disk storage device having a sealed bearing tube
EP0098009A1 (en) * 1982-06-28 1984-01-11 Atasi Corporation Memory storage apparatus having improved housing and base plate arrangement
EP0098010A1 (en) * 1982-06-28 1984-01-11 Atasi Corporation Unitary assembly, including spindle mount, transducer actuator support structure and magnetic shielding, for disc drive
EP0149228A2 (en) * 1983-12-28 1985-07-24 PAPST-MOTOREN GmbH &amp; Co. KG Electric motor, in particular a commutatorless direct current motor
EP0425478A2 (en) * 1983-12-28 1991-05-02 PAPST LICENSING GmbH External rotor motor, in particular collectorless direct-current motor
EP0149228A3 (en) * 1983-12-28 1986-03-05 Papst-Motoren Gmbh & Co. Kg Electric motor, in particular a commutatorless direct current motor
DE3347360A1 (en) * 1983-12-28 1985-07-11 Papst Motoren Gmbh & Co Kg electric motor
USRE33813E (en) * 1983-12-28 1992-02-04 Papst-Motoren Gmbh & Co. Kg Electric motor, particularly a brushless direct current motor
EP0425478A3 (en) * 1983-12-28 1992-10-07 Papst-Motoren Gmbh & Co. Kg Electric motor, in particular collectorless direct-current motor
EP0151260A1 (en) * 1984-02-07 1985-08-14 Siemens Aktiengesellschaft Magnetic disc memory comprising a stack of discs with double sided bearing within a partially resilient casing
US4703374A (en) * 1984-02-07 1987-10-27 Siemens Aktiengesellschaft Magnetic disk memory having a disk pack seated at both sides in resiliently-designed housing
US4692827A (en) * 1984-02-07 1987-09-08 Siemens Aktiengesellschaft Divided housing for a magnetic disk drive comprising a peripheral sealing ring
WO1985003593A1 (en) * 1984-02-07 1985-08-15 Siemens Aktiengesellschaft Berlin Und München Storage device for a disk stack of a magnetic disk memory
EP0151258A1 (en) * 1984-02-07 1985-08-14 Siemens Aktiengesellschaft Divided housing with peripheral ring seal for magnetic disc memory
EP0253626A2 (en) * 1986-07-18 1988-01-20 Fujitsu Limited Magnetic disc device
EP0253626A3 (en) * 1986-07-18 1989-05-24 Fujitsu Limited Magnetic disc device
WO2009071371A1 (en) * 2007-12-03 2009-06-11 Robert Bosch Gmbh Electric motor having a motor housing
FR3036889A1 (en) * 2015-05-29 2016-12-02 Valeo Systemes Thermiques Electric motor with electronic switching and forced air device corresponding
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Also Published As

Publication number Publication date Type
DE3144629C2 (en) 1991-08-08 grant
GB2092834B (en) 1984-12-12 grant
DE3144629A1 (en) 1982-07-08 application
DE3153746C2 (en) 1995-04-13 grant

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Effective date: 20011202