JPH05109178A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To decrease a shaft shake of a hub by fixing a spindle output shaft integrated with the hub to a housing via respective ball bearings and supplying two spindle output shafts themselves at the edge parts. CONSTITUTION:The hubs 1a, 1b are integrated into one body with the hub and the spindle output shaft and are connected by interposing one steel ball 8 in a middle of two ball bearings 7a, 7b. The rotational force generated with a rotor 4 is transferred to the hum 1a, the ball bearings 7a to rotate them smoothly. At this time, in order to impart a rotation synchronized to the hub 1b, the ball bearings 7b, the hubs are fastened by interposing the steel ball 8. The hubs are formed at a nearly same length being divided into halves, so the shaft shake is less than the shaft on the other side and the workability becomes better, since the hub is formed by being integrally molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device for rotating a magnetic recording medium by a spindle motor and a hub bearing mechanism.

[0002]

2. Description of the Related Art A conventional magnetic disk device shown in FIG. 6 is a hub 1 for mounting and holding a magnetic recording medium at the center of rotation when a spindle motor rotates the magnetic recording medium.
Two ball bearings 7A, 7A, 1B are provided at both ends of the spindle output shaft 10 to rotate two magnetic recording media at the same time, and to hold the spindle output shaft 10 in rotation.
B, a cylindrical housing 6A for fixing and holding the ball bearings 7A, 7B, and an inner diameter of each of the ball bearings fixedly held at the upper end portion and the lower end portion of the housing 6A, the spindle output shaft 10 is inserted. And a hub bearing mechanism configured as described above.

[0003]

In this conventional magnetic disk device, since the spindle motor has a structure in which the hub member is attached to the spindle output shaft, a hub attaching operation is required in the assembling process. There is a problem that it is difficult to obtain the surface accuracy of the hub member.

[0004]

A magnetic disk device according to the present invention comprises a rotor of a spindle motor rotated by a drive circuit, a first hub integrated with a spindle output shaft and rotated by the rotor, and a second hub. A spindle output shaft and a connecting mechanism for connecting the ends of the first hub and the spindle output shaft, and a ball bearing fitted to each spindle output shaft and fixed to the housing.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a side view of a first embodiment of the present invention, and FIG.
3 is a detailed cross-sectional view of the embodiment of FIG.

A rotor 4 of a spindle motor rotated by a drive circuit 5, a first hub 1a integrated with a spindle output shaft and rotated by the rotor 4, and a second hub 1b.
Output shaft and first hub 1a integrated into
A steel ball 8 for connecting the ends of the spindle output shaft, and ball bearings 7a, 7b fitted and fixed to the housing 6 for each spindle output shaft.

The hub and the spindle output shaft are integrated,
The hubs 1a and 1b, which are approximately the same in length, have ball bearings 7a and 7a, which are fixedly held in the housing 6 by making holes in the end surface of the shaft.
Two ball bearings 7a, each inserted in the inner diameter of 7b,
Hubs 1a and 1b are joined with one steel ball 8 interposed in the middle of 7b. The rotational force generated by the rotor 4 is the hub 1
a, transmitted to the ball bearing 7a and smoothly rotated. At this time, since the hub 1b and the ball bearing 7b are rotated in synchronization with each other,
The steel ball 8 is interposed and it fastens. By making the same length divided into two, it has less axial contact than one shaft,
Workability is improved by forming the hub by integral processing.

FIG. 3 is a side view of the second embodiment of the present invention. The difference from the first embodiment is that the hubs 11a and 11b are
Are connected at pin 9.

FIG. 4 is a side view of the third embodiment of the present invention. The hub 12 is different from the first and second embodiments.
Ball bearing 7 in which a and 12b are provided between ball bearings 7a and 7b
bind by c.

FIG. 5 is a side view of the fourth embodiment of the present invention. The difference from the first to third embodiments is that the hub 13a is
The hub 13b is provided with a concave hole at the shaft end thereof, the hub 13b is provided with a convex pin at the shaft end thereof, and the convex pin is inserted into the concave hole.
Join a and 13b.

[0011]

As described above, according to the present invention, the spindle output shaft integrated with the hub is fixed to the housing through the respective ball bearings, and the two spindle output shafts are connected at their ends. As a result, there is an effect that the assembling work becomes easy and the shaft runout of the hub is reduced.

[Brief description of drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a detailed sectional view of the first embodiment.

FIG. 3 is a side view of the second embodiment of the present invention.

FIG. 4 is a side view of the third embodiment of the present invention.

FIG. 5 is a side view of the fourth embodiment of the present invention.

FIG. 6 is a side view of an example of a conventional magnetic disk device.

[Explanation of symbols]

1a, 1b, 11a, 11b, 12a, 12b, 13
a, 13b Hub 2a, 2b Medium 3 Shield van 4 Rotor 5 Drive circuit 6 Housing 7a, 7b, 7c Ball bearing 8 Steel ball 9 Pin 10 Spindle output shaft

Claims (2)

[Claims] 1. A rotor of a spindle motor rotated by a drive circuit, a first hub integrated with a spindle output shaft and rotated by the rotor, a spindle output shaft integrated with a second hub, and the first hub. Magnetic disk device, comprising: a coupling mechanism for coupling an end portion of the hub with the spindle output shaft; and a ball bearing fitted to each spindle output shaft and fixed to the housing. 2. The magnetic disk drive according to claim 1, wherein the ends of the spindle output shafts of the first and second hubs are connected by a ball bearing.