JPH09298855A - Disk drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rotor portion from being displaced from a stator portion by fixing an O-shaped ring so as to project out part of the ring to a grooved strip portion and rattle other portion of the projected portion of the ring with a grooved strip portion where the ring is not fixed. SOLUTION: A grooved strip portion 11 is provided at the outer periphery of a bearing holder 2, and also a grooved strip portion 13 is provided at the inner peripheral portion 13 of a rotor bush 3 facing the grooved strip portion 11. Here, an O-shaped ring 4 is fixed and the ring 4 is formed with an elastic body such as rubber. Thus, when assembling a rotor 12 by inserting a shaft 1 to a bearing 2, even though an outer peripheral portion 14 of a groove larger than the groove strip portion 11 provided at the bearing holder 2 is larger than the inner periphery of the O-shaped ring 4, a predetermined assembly is possible with a smaller force. O-shaped ring 4 contacts to the corner of the grooved outer peripheral portion 14 in the assembly rotor 12 and the rotor cannot be pulled out easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device for information processing using a hydrodynamic bearing, and more particularly to a highly accurate and inexpensive rotor dropout prevention structure.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the rotor of a disk drive device used in a brushless motor or the like from slipping off from the stator, Japanese Patent Laid-Open No. 6-223494 discloses that a magnetic center of a core is displaced or a rotor suction yoke is separately provided. Mounting on the shaft, forming a groove on the shaft, forming a groove on the outer peripheral part of the bearing holder and attaching a fastening part on the rotor side, forming a screw on the inner periphery of the rotor and the outer peripheral part of the bearing holder, and attaching a metal stopper on the outer peripheral part of the rotor Alternatively, a structure in which thrust is provided on the rotor is disclosed.

FIG. 2 is a view showing a conventional disk drive device. 1 is a shaft, 2 is a bearing holder, 5 is a rotor yoke, 6 is a core, 7 is a coil, 8 is a magnet, 9 is a motor base, and 21 is a motor base. The convex portion 22 is a concave portion. A recess 22 is provided below the position where the rotor yoke 5 having the magnet 8 attached to the shaft 1 is fixed, and the recess 22 is provided over the entire circumference of the shaft 1. On the other hand, on the stator side fixed to the motor base 9, the core 6 on which the coil 7 is wound is attached to the bearing holder 2, and the convex portion 21 is provided at a position corresponding to the concave portion 22 provided on the shaft 1 of the bearing holder 2. It is provided. The concave portion 22 and the convex portion 21 prevent the rotor from coming off.

[0004]

In the above-described conventional example, the effect of preventing the rotor from coming off is not sufficient, separate parts having a complicated structure and expensive are required, and machining of the shaft is required. In addition, depending on the position of the rotor, there is a case where parts are damaged or accuracy is deteriorated when the rotor is not effective or when the rotor is forcibly pulled out. The present invention provides a disk drive device that solves the above problems.

[0005]

In order to solve the above-mentioned problems, a disk drive device according to the present invention is provided with a shaft, a bearing holder for rotatably holding the shaft, and a coil provided on the bearing holder. A disk drive device comprising: a stator part composed of a wound core; and a rotor part mounted on the shaft and provided with a magnet at a position facing the coil, wherein A first groove concentric with the shaft is provided, and the first groove is formed on the inner peripheral surface of the rotor.
A second groove portion is provided so as to face the groove portion of
O made of an elastic member in the groove portion or the second groove portion.
The rotor portion is fixed by fixing the O-shaped ring so that a part thereof protrudes, and the protruding portion of the O-shaped ring is loosely engaged with the groove portion on which the O-shaped ring is not fixed. Is prevented from falling off from the stator portion.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the same reference numerals are given to the same configuration as the conventional example,
Description is omitted. FIG. 1 is a diagram showing a disk drive device according to an embodiment of the present invention. 1 is a shaft, 2 is a bearing holder, 3 is a rotor bush, 4 is an O-shaped ring, 5 is a rotor yoke, 6 is a core, 7 is a coil, 8 is a magnet, 9 is a motor base, 11 and 13 are groove portions. , 14 are groove outer peripheral portions.

The operation of the disk drive device configured as described above will be described below. The bearing holder 2 attached to the motor base 9 is processed by die casting, cutting or the like with aluminum, zinc or the like. The shaft 1 supported by the bearing holder 2 constitutes a dynamic pressure bearing and constitutes the rotor 1.
2 is rotatable. A rotor bush 3 is fixed to the shaft 1 by adhesion, press fitting, caulking, or the like, and a magnet 8 for rotating the rotor 12 is provided on the inner peripheral portion of the rotor yoke 5. Further, a grooved portion 11 is provided on the outer periphery of the bearing holder 2, and a grooved portion 13 is also provided on the inner peripheral side of the rotor bush 3 facing the grooved portion 11. The O-shaped ring 4 is fixed there, but the O-shaped ring 4
Is formed of an elastic body such as rubber, so that when the shaft 1 is inserted into the bearing 2 and the rotor 12 is assembled, the groove outer peripheral portion 14 larger than the groove portion 11 provided in the bearing holder 2 is an O-shaped ring 4. Even if it is larger than the inner circumference, the predetermined assembly can be performed with less force.

The assembled rotor 12 cannot be easily pulled out because the O-shaped ring 4 hits the corner of the groove outer peripheral portion 14. Moreover, the O-shaped ring and the groove portion 11 form a labyrinth 15 to provide a sealing effect of preventing the lubricant from flowing out to the bearing formed by the shaft 1 and the bearing holder 2. When positively obtaining the sealing effect, the number can be increased by increasing the number of O-shaped rings in the vicinity of the bearing holder 2 and the rotor bush 3 as much as possible. Further, when the rotor 12 has to be pulled out and disassembled inevitably, the rotor 12 can be disassembled by forcibly pulling out the rotor 12 only by damaging the inexpensive O-shaped ring.

Alternatively, an O-shaped ring may be fixed to the groove portion 11 on the stator side, and may be loosely fitted in the groove portion 13 having a wider width.

[0010]

According to the present invention, the O-shaped ring is formed by providing elastic grooves in one of the grooves, both of which are provided with grooves on both sides of the rotor, which are concentric with each other and are concentric with each other. It is possible to prevent the rotor from slipping off by adding a simple structure in which the rotor is attached to engage with the other groove, and since the O-shaped ring is firmly attached to the groove, a sealing effect is obtained. Obtainable. Further, even when the rotor has to be pulled out and disassembled inevitably, only the O-shaped ring formed of the elastic member is damaged, and expensive parts can be disassembled without being damaged.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 shaft 2 bearing holder 3 rotor bush 4 O-shaped ring 5 rotor yoke 6 core 7 coil 8 magnet 9 motor base 11,13 groove part 14 groove outer peripheral part

Claims (1)

[Claims] 1. A stator portion comprising a shaft, a bearing holder for rotatably holding the shaft, a core wound around the bearing holder, and having a coil wound around the shaft; And a first groove portion concentric with the shaft on the outer peripheral portion of the bearing holder, and the first inner groove portion on the inner peripheral surface of the rotor. A second groove portion is provided so as to face the first groove portion, and a part of an O-shaped ring made of an elastic member protrudes from the first groove portion or the second groove portion. To prevent the rotor part from falling off from the stator part by fixing, and the protruding part of the O-shaped ring is loosely engaged with the groove part on which the O-shaped ring is not fixed. A disk drive device characterized by the above.