JPH09112548A - Hard disk driving device furnished with complex bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard disk driving device which has a good rotating property by a user using a bearing device into which fellow parts are already assembled, as it is, for a motor. SOLUTION: Balls 4 are filled between an outer peripheral rolling groove 2b formed on the inner peripheral surface of an outer ring 3; and an inner peripheral rolling groove 2a formed on the large diameter outer periphery of a two-step shaft 1 having the large diameter part 1a and the small diameter part 1b. To a complex bearing device composed by filling balls 8a between an inner peripheral rolling groove 6a formed on the outer periphery of an inner ring 7a fitted to the large diameter part 1b of the two-step shaft 1, and an outer peripheral rolling groove 6b formed on the end inner surface of a sleeve outer ring 5 consisting of a tube body, the hub 12 of a rotor 11 in a motor is fitted and fixed.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an improvement of a motor bearing in a hard disk drive.

[0002]

2. Description of the Related Art A spindle motor, for example, is used as a motor for a hard disk drive. The motor includes a shaft, a rotor, a base and a yoke holder, and the shaft is
The bearing is supported by a bearing device including inner and outer rings and balls provided on a sleeve of the bearing.

In the conventional bearing device, as shown in FIG. 6, in addition to two ball bearings A and B, cylindrical spacers C are individually manufactured as components, and these components are hard disk drives for users. Delivered to the device manufacturer,
The same manufacturer assembles these parts on the shaft D.

[0004]

As described above, in the bearing device for the motor in the conventional hard disk drive device, the manufacturer of the hard disk drive device must assemble the two ball bearings to the shaft through the spacers as described above. There is a problem.

(A) The shaft must be manufactured in accordance with the inner diameter of the inner ring of the ball bearing, and the shaft rigidity is restricted.

(B) It is necessary to finish the parallelism and flatness of both end faces of the spacer with high accuracy. (c) The contact between both end surfaces of the spacer and the end surface of the ball bearing outer ring must be uniform, and the processing and work for that purpose are not easy. (d) If the above conditions are not satisfied, shaft runout and disk runout may occur, and a hard disk drive device with high rotational performance cannot be obtained.

According to the present invention, such a problem can be solved, and a bearing device in which parts are already assembled can be used as it is for a motor in a manufacturer of a hard disk drive device to provide a hard disk drive device having good rotation performance. I chose

[0008]

According to a first aspect of the present invention, a hard disk drive device has an outer peripheral rolling groove formed on an inner peripheral surface of an outer ring and a large diameter of a two-stage shaft having a large diameter portion and a small diameter portion. Fill the ball between the inner circumference rolling groove formed on the outer circumference of the part,
Balls are filled between the inner peripheral rolling groove formed on the outer periphery of the inner ring fitted in the small diameter portion of the two-stage shaft and the outer peripheral rolling groove formed on the inner surface of the end portion of the sleeve outer ring made of a cylindrical body. The hub of the rotor of the motor of the hard disk drive is fitted and fixed to the composite bearing device.

According to a second aspect of the hard disk drive device of the present invention, an outer peripheral rolling groove formed on the inner peripheral surface of one end of a sleeve outer ring made of a cylinder, and a large diameter of a two-stage shaft having a large diameter portion and a small diameter portion. A ball is filled between the inner circumference rolling groove formed on the outer circumference of the part, and the inner ring of the ball bearing filled with balls between the inner ring and the outer ring is fitted to the small diameter part of the two-stage shaft, to a composite bearing device, The hub of the rotor in the motor of the hard disk drive is fitted and fixed.

In the first type, all the balls have the same diameter by making the outer diameter of the inner ring fitted in the small diameter portion of the two-stage shaft of the bearing device the same as that of the large diameter portion of the two-stage shaft. . In the second type, the outer diameter of the inner ring of the ball bearing is the same as the outer diameter of the large diameter portion of the two-stage shaft, and the outer and inner diameters of the outer ring are the same as the outer and inner diameters of the sleeve outer ring, respectively. By doing so, all balls have the same diameter.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an external perspective view of a hard disk drive device, and FIG. 2 shows a first embodiment of a hard disk drive device equipped with an outer rotor type motor of the present invention.
In the figure, reference numeral 1 indicates a two-stage shaft having a large diameter portion 1a and a small diameter portion 1b in the bearing device, and an inner peripheral rolling groove 2a is formed on the outer periphery of the large diameter portion.

An outer ring 3 is provided with a ball 4 between the outer peripheral rolling groove 2b formed on the inner peripheral surface of the outer ring and the inner peripheral rolling groove 2a of the large diameter portion, and is assembled to the large diameter portion. Reference numeral 5 denotes a sleeve outer ring that surrounds the two-stage shaft, and has an outer peripheral rolling groove 6b on the inner peripheral surface of the upper and outer end portions.
The outer peripheral rolling groove 6b is formed between the outer peripheral rolling groove 6b and the inner peripheral rolling groove 6a formed on the outer periphery of the inner ring 7a fitted to the small diameter portion 1b of the two-stage shaft. It has been assembled to. Further, by making the outer diameter of the inner ring 7a fitted in the small diameter portion 1b of the two-stage shaft 1 the same as that of the large diameter portion 1a of the two-stage shaft, all the balls 4, 8a have the same diameter.

In this embodiment, for example, the inner ring 7a is previously slidably fitted in the small diameter portion 1b of the two-stage shaft,
Next, an appropriate preload (preload) is applied to the inner ring from the upper end surface, and with this preload applied, the inner ring 7a is fixed to the small diameter part of the two-stage shaft with an adhesive or the like, and the outer ring, the sleeve outer ring and the inner ring are two-staged. Attach to the shaft.

Shaft 1 of bearing device assembled in this way Casing 10 in hard disk drive device
Is fixedly erected on the base 10a of the motor, and then the hub 12 formed on the lower surface of the center of the rotor 11 of the motor is fitted and fixed to the outer rings 3 and 5 of the bearing device. Reference numeral 13 is a magnet, 14 is a stator yoke in which a coil for energization is wound,
Reference numeral 15 is a yoke holder, 16 is a swing arm having a magnetic head 17 at its tip, and 18 is a magnetic disk.

FIG. 3 shows a hard disk drive device according to a second embodiment of the present invention, which uses another bearing device. In this embodiment, the two-stage shaft 1 in the bearing device is also used.
An inner circumferential rolling groove 2a is formed on the outer circumference of the large diameter portion.

An outer peripheral rolling groove 2b is formed on the inner peripheral surface of the lower end of the sleeve outer ring 5 which surrounds the two-stage shaft. The outer peripheral rolling groove 2b and the inner peripheral rolling groove 2a of the large diameter portion of the shaft are formed. A ball 4 is filled in between.

An inner ring 7a and an outer ring 7b are provided in the small diameter portion of the two-stage shaft.
And the inner ring 7a of the ball bearing 7 filled with balls 8b is fitted and fixed between the inner and outer rings. The outer diameter of the inner ring 7a of the ball bearing 7 is made the same as the outer diameter of the large diameter portion 1a of the two-stage shaft 1, and the outer ring 7b has the same outer diameter and inner diameter as the outer diameter and inner diameter of the sleeve outer ring 5, respectively. The balls 4 and 8b have the same diameter because of the diameter.

In this embodiment, for example, the inner ring 7a of the ball bearing is preliminarily slidably fitted in the small diameter portion 1b of the two-stage shaft, and then an appropriate preload (preload) is applied to the inner ring 7a from the upper end surface. Inner ring 7 with this preload applied
A is fixed to the small diameter part of the two-stage shaft with an adhesive, etc.
Assemble the outer ring and inner ring of the sleeve on the two-stage shaft. Reference numerals 9a and 9b in the drawing denote rolling grooves of the ball bearing inner and outer rings, and the balls are held by retainers (not shown).

In the above-mentioned first and second embodiments, all the balls have the same diameter, but balls having different diameters may be used on the large diameter side and the small diameter side.

The above is an example in which the motor of the hard disk drive device is of the outer rotor type, but in the case of an inner rotor type motor in which the magnet 13 is provided outside the hub 12 of the rotor 11 as shown in FIGS. There is also.

[0021]

In the motor of the hard disk drive device of the present invention, one end of the sleeve of the bearing device acts as an outer ring, and the sleeve is a sleeve outer ring of a composite body in which one outer ring is integrally formed. Then, it has the following actions and effects.

(A) In the motor, since the inner ring, outer ring, sleeve outer ring and ball of the composite bearing device have already been assembled to the shaft by the bearing manufacturer, the manufacturer of the hard disk drive device does not need to assemble these parts. By fitting and fixing the motor hub to the sleeve outer ring of the bearing device, the rotor of the motor can be easily attached to the bearing device. (b) In addition, since the inner circumferential rolling groove is formed directly on the outer circumference of the large diameter portion of the two-stage shaft in the bearing device, the conventional inner ring is not required, and therefore the shaft has a part with a large diameter. It can be made into a two-stage shaft, and the shaft rigidity can be increased. (c) Since the shaft can be made to have a large diameter and high rigidity, the resonance (resonance point) will be high, resonance with other members in the motor can be prevented, and the rotation performance and reliability of the motor will be improved. A hard disk drive device that can be improved and has less surface wobbling can be provided. (d) Only one conventional ball bearing is required for the bearing device, so only one inner ring is required, and the number of parts of the bearing device can be reduced. (e) Since the inner peripheral rolling groove is directly formed on the outer circumference of the large diameter part of the shaft, the inner ring is not required on the large diameter part side. Therefore, the outer diameter of the outer ring can be reduced by the amount of the inner ring. It is possible,
It is possible to provide a hard disk drive device that can meet the highest demand for smaller size.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a hard disk drive device.

FIG. 2 is a longitudinal sectional view showing a first embodiment of an outer rotor type motor of a hard disk drive device according to the present invention.

FIG. 3 is a longitudinal sectional view showing a second embodiment of an outer rotor type motor of a hard disk drive device according to the present invention.

FIG. 4 is a vertical cross-sectional view showing a first embodiment of an inner rotor type motor of a hard disk drive device according to the present invention.

FIG. 5 is a longitudinal sectional view showing a second embodiment of the inner rotor type motor of the hard disk drive device according to the present invention.

FIG. 6 shows a structure of a conventional bearing, (a) is a vertical sectional view showing a ball bearing and a spacer before assembly, and (b) is a vertical sectional view showing a state in which the ball bearing and the spacer are assembled to a shaft.

[Explanation of symbols]

 1 Two-step shaft 1a Large diameter part 1b Small diameter part 2a Inner peripheral rolling groove 2b Outer peripheral rolling groove 3 Outer ring 4 Ball 5 Sleeve Outer ring 6a Inner peripheral rolling groove 6b Outer peripheral rolling groove 7 Ball bearing 7a Inner ring 7b Outer ring 8a, 8b Balls 9a, 9b Rolling grooves 10 Casing 10a Casing base 11 Rotor 12 Hub 13 Magnet 14 Stator yoke 15 Yoke holder 16 Swing arm 17 Magnetic head 18 Magnetic disk

Claims (2)

[Claims] 1. A ball is filled between an outer circumferential rolling groove formed on the inner circumferential surface of an outer ring and an inner circumferential rolling groove formed on the outer circumference of a large diameter portion of a two-stage shaft having a large diameter portion and a small diameter portion. Then, a ball is filled between the inner peripheral rolling groove formed on the outer periphery of the inner ring fitted to the small diameter portion of the two-stage shaft and the outer peripheral rolling groove formed on the inner surface of the end portion of the sleeve outer ring made of the cylindrical body. A hard disk drive device equipped with a composite bearing device in which a rotor hub of a motor is fitted and fixed to the composite bearing device. 2. An outer circumferential rolling groove formed on the inner circumferential surface of one end of a sleeve outer ring made of a tubular body, and an inner circumferential rolling groove formed on the outer circumference of the large diameter portion of a two-stage shaft having a large diameter portion and a small diameter portion. To the composite bearing device in which the inner ring of the ball bearing having the balls filled between the inner ring and the outer ring is fitted in the small diameter portion of the two-stage shaft,
A hard disk drive device including a composite bearing device in which a rotor hub of a motor is fitted and fixed.