JPS633028Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a swing arm device for moving and positioning at least one magnetic head on a rotating rigid magnetic disk of a magnetic disk storage device for recording and reproducing digital data. a swing arm rotatable about a pivot axis or a plurality of swing arms spaced apart from each other to form a swing arm assembly pivotable about a pivot axis; a frame; and a swing arm; or a bearing device that rotatably supports the swing arm assembly on the frame, and includes first and second ball bearings each having an inner race and an outer race, a pivot bearing pin, and an inner race of the ball bearing in an axial direction relative to each other. means for securing the swing arm or swing arm assembly to the bearing pin; bearing housing means for engaging the outer race of the ball bearing and connecting to the frame; compression spring means for eliminating axial play in the loaded bearing;
The present invention relates to a swing arm device in which a bearing device is constituted by a bearing housing means and a fixing means for attaching a bearing housing means to a frame.

comprising one or more rigid magnetic disks,
Magnetic disk storage devices, which are used to record and reproduce digital data on at least one side of each magnetic disk, and usually both, are used on a large scale as peripheral devices for data processing devices such as computers.

The magnetic disk rotates at a high speed of, for example, 3,600 revolutions per minute, and the magnetic head attached to the end of the carrying arm device is moved to a predetermined position on the magnetic disk by the data processing device, and is moved to a specific track on the magnetic disk. Record data to or play data from this track. The carrying arm device includes a moving arm that moves linearly in the radial direction or pivots about a pivot axis parallel to the axis of rotation of the magnetic disk. The present invention relates to the latter type of carrying arm device, referred to herein as a swing arm device.
The magnetic head must move over the magnetic disk as quickly as possible to minimize the time required to position itself on the correct track and the time required to record and read data. A magnetic disk is manufactured with high flatness, and a magnetic head is floated on an extremely thin film of air that is in close contact with the surface of the magnetic disk.

In many cases, the magnetic head is mounted on a resilient magnetic head support. This support causes the magnetic head to float on the film of air and provides an elastic load that applies precisely defined pressures to the magnetic head. In order to reduce the outer diameter dimensions of magnetic disk storage devices, attempts have been made by many manufacturers to place magnetic disks as close to each other as possible. Therefore, especially when inserting the carrying arm device between two disks, the carrying arm device must be as flat as possible and move as close as possible to the magnetic disk surface. The swing arm device must never touch the magnetic disk surface. This is because the magnetic disk becomes unusable.

Therefore, the carrying arm device of a magnetic disk storage device must be precisely manufactured with a predetermined precision.

A swing arm device of the type described above is described in US Pat. No. 4,150,407. Such known swing arm devices include one or more aluminum swing arms in the form of bifurcated levers, which arms are pivotable about a pivot axis disposed between their ends. A magnetic head unit having a magnetic head and a resilient magnetic head carrier is disposed near one end of each swing arm. The carrier is rigidly coupled to the carrying arm. A control coil is arranged at the other end of the swing arm. This control coil belongs to an electromagnetically and electrically controllable actuating means, which makes it possible to give the swinging arm a rotational movement about its rotational axis, thus moving the magnetic head approximately radially over the magnetic disk. can be done.

For models with multiple swing arms, the swing arms are spaced apart and stacked one on top of the other, and the swing arms are combined to form a swing arm assembly that is rotatable about a pivot axis. do. Each swing arm carries an individual flattened control coil which also combine to form a spaced apart control coil assembly. The swing arm assembly is supported on the frame by a bearing device. This bearing device includes two ball bearings and a bearing pin, and the inner races of the ball bearings are fixed to the bearing pins by suitable means, and the inner races are spaced apart from each other in the axial direction. Fit the outer race of the ball bearing into the bearing housing. This bearing housing is screwed to the deck of the magnetic disk storage device, and play in the axial direction of the bearing is eliminated by a compression spring provided between the outer races. A control coil moves within the permanent magnet stator. The stator includes a stator frame and a plurality of flat axially magnetized permanent stator magnets. By connecting the stator magnets to the stator frame and creating air gaps between the stator magnets for each flat control coil, each control coil can move within an axial permanent magnetic field within the air gap between the stator magnets. Iron stator end plates protruding above the control coil and stator magnets are disposed on both sides of the stator, and the outermost stator magnet is mounted thereon, and the end plates close the axial permanent magnetic field. Each control coil is constructed by wrapping a conductive material onto a plastic coil frame, and the synthetic resin forms a single structural unit with the control coil. The control coil is attached by clamping and gluing to the end of the swingarm farthest from the magnetic head.

The magnetic head moves generally radially over the magnetic disk at high speed to minimize the time required to position itself on the track and to record and read data. The swing arm or swing arm assembly therefore moves suddenly, creating significant inertial forces. The bearing arrangement must therefore be robust and stable. The present invention provides a swing arm device of the type described above. The device of the present invention is robust, stable, and has a small number of components, making it suitable as a small magnetic disk storage device intended for large-scale use, such as a peripheral device for a personal computer. The present invention arranges first and second ball bearings on both sides of the swing arm or swing arm assembly, and constitutes a bearing housing means with the first and second bearing housings for the first and second ball bearings, respectively. The present invention is characterized in that a pressing spring means is disposed between the outer race of one of the two ball bearings and the frame in order to apply a load to the ball bearing in the axial direction of the other ball bearing. . The safety of the bearing arrangement is achieved by supporting the swing arm or swing arm assembly on both sides, so that the two ball bearings are equally loaded. Compared to the known types of swing arm devices mentioned above, the symmetrical bearing arrangement results in less deformation of the bearing pin. Another advantage is that the overall mounting height of the swing arm device can be reduced.

The small number of parts required by the embodiment of the present invention is characterized by the following points: That is, the means for fixing the inner race of the ball bearing and the means for fixing the swing arm of the swing arm assembly are constituted by coupling means for pressing the inner races of the ball bearings against each other in the axial direction, and the swing arm or It is characterized by a fixed swing arm assembly.

Another simple construction and low cost embodiment is an extruded tube with a central through hole for an outer race in the ball bearing and a plurality of small diameter through holes located around the central through hole. The present invention is characterized in that each bearing housing is constructed from the above, and a fixing means for fixing the bearing housing means is constructed from a tut pin screw fitted into the small diameter through hole.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The magnetic disk storage device comprises a frame 1 to which a swing arm device 2 is rigidly attached. 2
A number of rigid magnetic disks 3 and 4 are arranged coaxially and spaced apart from each other on a common spindle 5, and
Rotate around axis 6. The swing arm device 2 and the magnetic disks 3, 4 are covered with a plastic cover 7. This cover protects the magnetic disks 3, 4 from dust and other contaminants. For the sake of simplicity, explanations and illustrations of those parts of the magnetic disk storage device that are not related to the present invention will be omitted, except for the box-shaped unit 8 that houses the electronic control circuitry necessary for the operation of the magnetic disk storage device.

The swing arm device of the present invention will be explained in detail with reference to FIG. This swing arm device is used to move and position four magnetic heads 9-12 relative to two rigid rotating magnetic disks 3,4. These magnetic heads are spaced apart from each other by a distance corresponding to the spacing between the magnetic disks 3 and 4, and are arranged on a single swing arm 14. This arm is rotatable about an axis 13. or,
The magnetic heads are mounted together in a single mounting device 15. This mounting device is provided with surfaces, recesses, and screw holes necessary for positioning and mounting the magnetic head on the swing arm. The attachment device 15 is rigidly attached to the swing arm by adhesive. For this adhesion, the method proposed in Dutch Patent Application No. 8101824 is used.

Each of the magnetic heads 9 to 12 is disposed on an elastic magnetic head support 9a to 12a, respectively, and a fixing part 9b to 12b is provided at one end of each of these supports, and a fixing bush 9C to 12C is provided to each of these fixing parts. A through hole 16 is formed in the mounting device 15, into which a fixing bush is fitted leaving a slight gap. In order to mount the magnetic head unit (consisting of a magnetic head, an elastic magnetic head support and a fixing part) on the mounting device 15, a slightly larger ball is pushed in by the associated fixing bush, so that the gap between the fixing bush and the through hole is reduced. remove. Such magnetic head units are commercially available.

Attachment device 15 and magnetic head 9 disposed thereon
The center of gravity of the assembly consisting of . Other parts of the magnetic head unit can also be arranged in this way. However, these components collectively have substantially less mass than the magnetic head and mounting system.

The mounting device 15 includes a plurality of protrusions 1 for mounting the magnetic heads 9 to 12 at regular distances from each other.
7, 18, 19, and these projections constitute a comb. The attachment device includes a plurality of parts 20, 2 that are removably attached to each other and have comb-like protrusions.
1,22. parts 20 and 22 with bolt 2
3 and 24 to be attached to the central part 21. Before connecting the magnetic heads 10, 11 to the projections 18 by means of the fixing bushes 10C, 11C, the portion 21 is glued to the swing arm 14 using the method previously described. part 2
0 and 22 to the center part 21 with bolts 23 and 24.
Before connecting the magnetic heads 9, 12 to the part 2
Connected to the protrusions 17 and 19 of 0 and 22. This makes it easier to attach the easily damaged magnetic head to the attachment device 15.

The swing arm has a first end 25 and a second end 26. Magnetic heads 9-12 are connected to the swing arm near the first end 25. The swing arm device includes a permanent magnet stator 27 having flat permanent magnets 28 and 29 for the stator, and these magnets are spaced apart from each other, with an air gap 30 between them as shown in FIG.
form. A flat control coil 31 made of a flat conductive material is disposed within this gap, and this coil is connected to the swing arm 14. The swing arm 14 is rotatably supported by a bearing device 32.
The flat control coil 31 is inserted into the hole 3 of the swing arm 14.
Placed within 3. The swingarm is die-cut from the aluminum sheet, and during this die-cutting operation hole 3 is
form 3. A bearing arrangement 32 is located near the second end 26 of the swing arm, and a control coil 31 is disposed between the first end 25 and the second end 26 of the swing arm.

The swing arm is constructed from a single flat sheet of material, and the thickness of the flat control coil 31 is approximately equal to the thickness of the sheet material. Swing arm hole 33
Since the shape corresponds to the outer shape of the control coil 31, the coil fits into the hole with a gap.

The control coil is glued to the swing arm 14 and secured to the wall of the hole 33 by an adhesive layer not visible in FIG. Since the control coil is located in the plane of the swing arm, the swing arm to which the control coil is glued constitutes a flat unit of approximately uniform thickness throughout. The control coil winding 34 is made of conductive material and wound around a central flat plastic coil frame 35. The conductive material is not formed from thin copper wire as in conventional control coils, but from thin aluminum strips 36. Its width is the coil thickness d
be equal to and sufficiently thin. The adhesive for gluing the control coil 31 to the wall of the hole 33 is mixed with aluminum powder to ensure sufficient heat transfer between the coil and the sheet material of the swing arm.
The two outermost magnetic heads 9 and 12 of the stacked magnetic heads 9 to 12 are shielded from spurious magnetic fields by Mumetal (trade name) shields 37 and 38. These shields project outwardly beyond their respective magnetic heads and are connected to the swing arm 14 via attachment devices 15. Opening 3 in shield
9, 40 and attach these shields to the mounting device 1.
5 parts 20, 22 together with bolts 23, respectively.
24 connects to the central part 21 of the mounting device.
An integrated circuit 41 is mounted on the lower shield 38 and processes the signals from the magnetic heads 9-12. Thus, the signal from the magnetic head can be amplified before being sent to the signal processing section of the magnetic disk storage device. Integrated circuit 41 is attached to a flexible plastic strip 43 provided with conductive tracks 42. Strip 43 is attached to shield 38 at first end 44. The plastic strip 43 is connected to the multi-contact connector 46 near the second end 45.
It is connected to the fixed connector of the frame 1 of the magnetic disk storage device through. The plastic strip 43 is provided with first and second freely movable portions 47 that do not impede movement of the swing arm 14.
4 and 45.

The bearing device 32 that rotatably supports the swing arm includes a first ball bearing 48 and a second ball bearing 49, which are connected to inner races 50, 51 and outer races 52, 53, respectively.
and has. Two inner races 50, 51 are attached to a bearing pin 54 by a snap ring 55 and a nut 56 so as to be spaced apart from each other in the axial direction. Ball bearings 48 and 49 are located on both sides of the swing arm 14. Bearing pin 5 on swing arm
An opening 57 for 4 is formed. Rings 58, 59 are disposed on each side of the swing arm to hold the swing arm between inner races 50, 51 for ball bearings 48, 49. The outer races 52, 53 of the ball bearing are engaged with a bearing housing comprising first and second housing portions 60, 61, respectively. Outer lace 52,
The axial gap between 53 is removed by pressing in the axial direction with a compression spring of the disc spring 62 type. Belleville spring 6
2 is attached to the top of the upper ball bearing 48 near the outer race 52. The ball bearings are slidably fitted into the bearing housings 60 and 61, and the disc springs 62 press both ball bearings together in the axial direction. Each bearing housing consists of a single extruded tube with a central through hole 63 for the outer races 52, 53 of the ball bearings 48, 49, and three mutually parallel holes arranged around the central hole 63. A small diameter through hole 64 is provided. Bearing housings 60, 61 are attached by tuft pin screws 65 that engage holes 64.

A permanent magnet stator 26 is provided, one on each side of the stator.
2 iron stator end plates 66,
67 are mounted on the stator frame, and these stator end plates protrude above the control coil 31 and stator magnets 28, 29. The stator magnet is glued to the stator end plate. The stator magnet is axially magnetized in the direction of the rotation axis 13 of the swing arm 14. Stator magnet 28 includes two oppositely polarized regions 28a, 28b.
The magnet 29 also has two oppositely polarized regions 29a, 29.
Contains b. On the side facing control coil 31, region 28a is polarized oppositely to region 29a, and region 28b is polarized oppositely to region 29a, thereby placing the portion of the control coil between the stator magnets in an oppositely polarized permanent magnetic field. The permanent magnetic field in the axial direction is 2
It is closed by two iron end plates 66, 67. It is clear that instead of the integral stator magnets 28, 29, a plurality of segmented magnets may be used. As an example, the stator magnet 28 can be configured in two parts: a region 28a belonging to one stator magnet and a region 28b belonging to another stator magnet. End plate 66 of stator 27,
67 over the bearing pin 54 and the swing arm 14
The bearing housings 60 and 61 are attached to the end plates 66 and 67 with tuft pin screws 65. Thus, the end plates 66, 67 also constitute frame plates of the bearing device 32. two end plates 66,
In addition to 67, the stator 27 has three spacers 68
~70. Three bolts 71-73 and their associated nuts 74-76 connect end plates 66, 67 and three spacers 68-7.
0 is assembled to form a rigid unit that constitutes the stator frame. Since the bearing housings 60 and 61 are attached to the stator frame, the stator frame also constitutes the frame for the completed swing arm device, and the stator end plate 67 is also used for attaching the completed swing arm device to the deck 77 of the magnetic disk storage device. Use as a base plate. Means for connecting the swing arm device 2 to the deck 77 are not shown, but include common screw means.

In the illustrated embodiment, the swing arm device is equipped with a tacho coil 78 which is connected to the swing arm 14 and is movable within a permanent magnetic field in order to generate an induced voltage that is a measure of the rotation speed of the swing arm 14. For this purpose, permanent tacho magnets 79, 80 are arranged on the outside of the stator end plate 67, and these magnets are oriented axially, i.e. along the rotation axis 13.
polarize in the opposite direction. Instead of these two magnets, a single flat magnet with oppositely polarized regions can be used. The stator end plate 67 also has the function of closing the axial magnetic field generated by the two octopus magnets 79, 80 on one side. On the side of the stator end plate 67, the bearing pin 54 is fitted with a flat octopus coil 78, such as a control coil 31, which passes through an opening 82 in the stator end plate and has a free end 81 projecting from its outside. Installed on 81,
It is possible to move within the permanent magnetic field generated by the octopus magnets 79 and 80. An iron octopus end plate 84 is arranged parallel to and at a certain distance from the stator end plate 67. The tacho coil 78 is connected to the stator end plate 67 and the tacho end plate 8.
4, leaving a gap between the flat octopus magnets 79 and 8.
Due to the movement parallel to zero, the axial permanent magnetic field of the octopus magnet is closed by the stator end plate on the one hand and the octopus end plate on the other hand. Tighten the stator end plate 84 with the pin screws 85 to 8.
8 to the underside of the deck 77, but may alternatively be attached to the stator end plate via other spacer means. The tacho magnets 79 and 80 are placed in the opening 89 of the deck 77 together with the tacho coil 78.

The two stator end plates 66, 67 are constructed from substantially similar plates and are stamped and formed from magnetizable sheet material. For this reason, the stator end plate can be manufactured in a simple manner and at low cost. The reason for this is the outstanding point that only one type of stator end plate needs to be manufactured.
Further, the requirements placed on manufacturing accuracy are not strict, and there is no need for any machining of the stator end plate after die-cutting and forming. As shown in FIG. 1, the stator magnets 28 and 29 extend slightly beyond the edges of the stator end plates 66 and 67, respectively, and
1 protrudes in a direction substantially transverse to the rotation direction.

A stop 90 is provided whose opposite sides 91, 92 cooperate with respective side walls 93, 94 of the recess 95 of the swing arm 14. Opposite sides 91, 92 of stop 90 limit rotation of the swing arm between first and second positions.
Figures 4 and 5 show the swing arm 14, respectively.
a first or inner position and a second or outer position. Stop 90 is constructed of rubber and is movable between an operating position shown in FIGS. 4 and 5 and a maintenance position shown in FIG. The stop entirely made of elastic rubber constitutes a freely rotatable stop cam that is suitably fitted to the spacer 68. For this purpose, the stop has an opening 96 slightly smaller than the outer diameter of the space 68. The aperture is eccentric so that the stop cam can rotate eccentrically between an operating position and a maintenance position. The stop cam is rotated 90 degrees in the maintenance position.

In this position, the side walls 93, 94 of the recess 95 cooperate with the opposite sides 97, 98 of the stop cam. Since the two sides are located closer to each other than the two sides 91 and 92, the swing arm 14 can be rotated over such a large range for maintenance purposes, and the magnetic heads 9 to 12 can be moved around the magnetic disks 3 and 4. Place it next to the surface. This position is also used during assembly of the magnetic disk storage device to allow the magnetic head to be attached to the device without damaging it.

In magnetic disk storage devices, multiple swing arm devices can be used, for example, on either side of a deck or frame plate, or stacked one on top of the other. Numerous embodiments are possible within the scope of the invention. For example, the ball bearings do not have to be mounted on the stator end plate, but may be mounted on another frame part, for example a separate bearing frame. In such an embodiment, the stator and the bearing arrangement with the stator or swing arm assembly may be separately mounted to the deck of the magnetic disk drive, such as the swing arm arrangement known from U.S. Pat. No. 4,150,407. .

[Brief explanation of the drawing]

Figure 1 is a plan view of a magnetic disk storage device, Figure 2 is a plan view of a magnetic disk storage device;
The figure is a side view of the device shown in FIG. 1, FIG. 3 is an exploded perspective view of the swing arm device of the present invention used in the device shown in FIGS. 1 and 2, and FIGS. FIG. 3 is a diagram showing a swing arm of the invented swing arm device. 1... Frame of magnetic disk storage device, 2...
...Swing arm device, 3, 4...Magnetic disk, 5...Spindle, 7...Plastic cover, 8...Box unit, 9-12...Magnetic head, 14...Swing arm, 15...Mounting device , 17, 19... protrusion, 20, 22... both side parts, 21... central part, 23, 24... bolt,
27... Stator, 28, 29... Stator magnet, 31... Control coil, 32... Bearing device, 3
3...hole, 35...plastic coil frame, 3
7, 38...Shield, 41...Integrated circuit, 42
... Conductive track, 43 ... Plastic strip, 46 ... Multi-contact connector, 48, 49 ...
Ball bearing, 50, 51... Inner race, 52, 53... Outer race, 54... Bearing pin, 58, 59... Ring, 60, 61... Bearing housing, 62... Belleville spring, 65... Tatsupin screw , 66, 67... Stator end plate, 68-70... Spacer, 71-73... Bolt, 74-76... Nut, 77... Swing arm device deck, 78... Octopus coil, 79,
80... Octopus magnet, 84... Octopus end plate.

Claims (1)

[Claims for Utility Model Registration] 1. At least one magnetic head 9 to 1 on a rotating rigid magnetic disk 3, 4 of a magnetic disk storage device for recording and reproducing digital data.
Swing arm device 2 for moving and positioning 2
one swing arm 14 pivotable about a pivot axis 13 or a plurality of swing arms spaced apart from one another to form a swing arm assembly pivotable about the pivot axis; and a frame 1, and a bearing device rotatably supporting the swing arm or the swing arm assembly on the frame, and first and second balls each having an inner race 50, 51 and an outer race 52, 53. bearings 48, 49, pivot bearing pin 54, inner race 50 of the ball bearing,
means 55, 56 for securing the swing arm or swing arm assembly to the bearing pin 51 axially spaced from each other; means for securing the swing arm or swing arm assembly to the bearing pin; bearing housing means 60, 61 for mating and connecting to the frame; compression spring means for removing axial play in the bearing that applies an axial load to the outer race; and fastening for attaching the bearing housing means to the frame. In the swing device, the bearing device includes: the first and second ball bearings 4;
8, 49 are arranged on either side of the swing arm 14 or the swing arm assembly, and the bearing housing means comprises first and second bearing housings 60, 61 for the first and second ball bearings, respectively. In order to apply a load to the ball bearing in the axial direction of the other ball bearing, the pressing spring means 62 is disposed between the outer race 52 of one of the two ball bearings 48 and the frame. A swing arm device characterized by: 2. The means for fixing the inner races of the ball bearings 48, 49 and the means for fixing the swing arm 14 of the swing arm assembly are coupling means 55 for pressing the inner races of the ball bearings together in the axial direction;
56, and the swing arm 14 or the swing arm assembly is fixed between the means, as claimed in claim 1. 3. An extruded tube having a central through hole 63 for one of the outer races 52, 53 of the ball bearings 48, 49 and a plurality of small diameter through holes located around the central through hole. From each of the bearing housings 60, 6
1, and a fixing means for fixing the bearing housing means is constructed from a tassel pin screw 65 fitted in the small diameter through hole.