JPH0273566A - Motor for driving magnetic disk - Google Patents

Abstract

PURPOSE:To improve impact resistance by fixing, with screws, a bracket assembly having a fitting part smaller than a stator core and a spindle assembly having a housing which has a fitting part to be fitted in it. CONSTITUTION:The spindle assembly consists of a cylindrical part holding ball bearings 102a and 102b, a spacer 114, a pre-load spring 111 and a magnetic flow seal 110, a housing 112 having a fitting part 115 at one end of the cylindrical part and provided with a tap 116 at one end of the fitting part, a hub 104 whose inner circumference surface is provided with a magnet 105 and a shaft 101 inserted in the hub 104. The bracket assembly consists of a bracket 103 having a fitting part 117 with the spindle assembly, a printed wiring board 108 on which electronic parts are mounted and a coil 107, by fixing the spindle assembly to the bracket assembly with the screws, the ball bearings 102a and 102b having a large major diameter can be used and the impact resistance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic disk drive motor (hereinafter referred to as a motor) for rotationally driving a magnetic disk of a magnetic disk device.

[Background Art] As computer systems become thinner, smaller, and larger in capacity, there is an increasing need for magnetic disk drive motors to be thinner and smaller. Further, with the spread of portable personal computers, magnetic disk drives are required to have ML resistance, and as a result, countermeasures against impact resistance of motors are required.

An example of a conventional motor will be described below with reference to the drawings.

FIG. 4 shows a sectional view of a conventional motor.

In the figure, 1 is a shaft, 2a and 2b are ball bearings attached to the shaft 1 at intervals in the axial direction, 3 is a bracket that fixes the ball bearings 2a and 2b, and 4 is attached to one end of the shaft 1. 5 is a magnet attached to the hub 4, 6 is a stator core attached to the bracket 3, 7 is a coil wound around the stator core 6, 8 is one end of the coil and a coil for supplying current. A printed circuit board with an electronic component 9 mounted thereon; 10, a magnetic fluid seal for preventing dust from entering through the ball bearings 2a, 2b disposed on the upper part of the bracket 3; and a magnetic fluid seal for preventing grease from scattering from the ball bearings 2a, 2b; Ball bearings 2a and 2 inserted into the gap between the ball bearing 2b and the bracket 3
A preload spring 12 applies preload to b, and a retaining ring 12 determines the height position of the ball bearing 2b.

The operation of the motor having such a structure will be explained next.

When a current is passed through the coil 7 wound around the stator core 6 in the magnetic field generated by the magnet 5 attached to the hub 4, the hub 4 and shaft 1 rotate together, working to drive the magnetic disk at a predetermined rotation speed. .

Problems to be Solved by the Invention However, in the conventional motor structure described above, the outer diameter of the ball bearings 2a, 2b is larger than the hub 4. Magnet 5. Since the stator core 6 and the bracket 3 are interposed between the stator core 6 and the bracket 3, it is subject to these restrictions, and a ball bearing with a large diameter cannot be used.

Therefore, there was a problem regarding impact resistance.

Moreover, if a problem occurs during assembly of the motor, the entire motor must be discarded. Also, motor mounting surface A
Since the magnetic disk support is strictly required to have surface B and height dimensional accuracy, there is a problem in that the motor mounting surface A or the magnetic disk support surface B must be machined after the motor is completed.

The present invention solves the above-mentioned conventional problems, and aims to provide a motor configuration that improves impact resistance, facilitates parts replacement, and does not require processing after assembly.

Means for Solving the Problems To achieve this object, the motor of the present invention includes a spindle assembly having a housing in which a ball bearing can be disposed on one side of the stator core, a fitting part, and a bracket assembly and a fitting part. It has an integrated configuration.

With this configuration, the outer diameter of the ball bearing is limited only by the /A bracket and the housing, allowing the use of ball bearings with larger outer diameters and making it easy to separate the spindle assembly and bracket assembly. This makes it possible to improve impact resistance and reduce costs.

Example Embodiments of the present invention will be described above with reference to the drawings.

FIG. 1 is a sectional view of a motor in one embodiment of the present invention, FIG. 2 is a sectional view of a spindle assembly, and FIG. 3 is a sectional view of a bracket assembly.

101 is a shaft, 102a and 102b are ball bearings, 103 is a bracket, 104 is a hub fixed to one end of the shaft 101, and a magnet 105 is attached to the lower end of the inner peripheral surface.

106 is a stator core fixed to the bracket 103,
A coil 107 is wound. 108 is a printed circuit board, 109 is an electronic component, 110 is a magnetic fluid seal, 111
is a preload spring.

Each of the above-mentioned components is a functional part similar to each component described in the conventional example shown in FIG. The spindle assembly includes ball bearings 102a and 102b.

Spacer 114. Preload spring 111. Magnetic fluid seal 11
0, a fitting part 115 at one end of the cylindrical part, and a tap 116 at one end of the fitting part 115.
It consists of a housing 112, which has a magnet 105 on its inner circumferential surface, and a shaft 101 into which the hub 104 is inserted. hl is measured. The bracket assembly has a fitting part 1 with the spindle assembly.
Bracket 103 with 17. It consists of a printed circuit board 108 to which electronic components 109 are soldered, and a stator core 106 around which a coil 107 is wound.
The height h2 between the motor mounting surface A and the surface of the spindle assembly pot support is measured. The spindle assembly is a bracket♀■
It is fixed three-dimensionally with screws 113.

Therefore, the motor of the present invention also has a hub 10 similar to the conventional example.
The rotational position of the magnet 105 provided on the inner peripheral surface of the magnet 105 is detected by an electronic component 109 including a position detection element, and the electronic circuit distributes current to the coil 107 to generate torque, thereby rotating the magnet 107.

As described above, according to this embodiment, the spindle assembly having the housing 112 having the fitting portion 115 is attached to the screw 1.
By fixing the ball bearing to the bracket assembly at 13, a ball bearing having a larger outer diameter than the conventional ball bearing can be used, thereby improving +TifTi properties. In addition, since the spindle assembly and bracket can be easily separated using the screw 113, if a problem develops in either the spindle assembly or the bracket, there is no possibility of an abnormality occurring. You only need to replace the solid body (there is no need to discard the entire motor.Moreover, by selecting the height hl bracket in the spindle assembly Since the height of the motor can be kept within the required dimensional tolerance and no machining is required after the motor is completed, costs can be reduced.

In this embodiment, the spindle assembly is provided with a tap 116 and fixed to the bracket assembly with screws, but the spindle assembly may be fixed to the bracket by press-fitting or adhesive bonding.

In this case, by arranging the ball bearing on the stator core, a ring with a large outer diameter can be used, thereby improving impact resistance.

Advantages of the Invention As is clear from the above description, the present invention includes a bracket assembly having a mating portion smaller than the stator core, and a housing having a mating portion that is mated with a plano 7 piece assembly smaller than the stator core. By providing the spindle assembly, impact resistance can be improved. In addition, by providing a tap at one end of the housing and fixing the spindle assembly to the bracket assembly with screws, parts replacement is easy, and machining is not required after the motor is completed, reducing production costs. Accordingly, it is possible to realize a magnetic disk drive motor that can obtain excellent effects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a motor for driving a magnetic disk according to an embodiment of the present invention, FIG. 2 is a sectional view of a spindle assembly, and FIG. 3 is a sectional view of a bracket assembly. FIG. 4 is a sectional view of a conventional magnetic disk drive motor. 101...Shaft, 102a, 102b...
... Ball bearing, 103 ... Bracket, 104 ... Hub, 105 ... Magnet, 106 ... Stator core, 112 ...
...Housing, 113 ...Screw, 11
5,117...Fitting part, 116...
·Tap. Name of agent: Patent attorney Shigetaka Awano

Claims (1)

[Claims] (1) In a magnetic disk drive motor equipped with at least one magnetic disk having an opening in the center,
It has a shaft rotatably supported by a ball bearing, a hub that is fixed to the shaft and has a portion for attaching the magnetic disk, and has a magnet provided on its inner circumferential surface, and a coil that faces the inner circumferential surface of the magnet is wound thereon. a housing having a cylindrical portion that supports the ball bearing and a housing having a fitting portion with the bracket assembly that is smaller than the inner diameter of the stator core; and a spindle assembly;
A magnetic disk drive motor in which the bracket assembly and the spindle assembly are integrated at a fitting portion. (2) A magnetic disk drive motor according to claim 1, wherein a tap is cut in the fitting portion of the spindle assembly and is fixed to the bracket assembly with a screw.