JP3026109B2 - Rotating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine for use when it is necessary to keep the space outside the rotating machine clean, such as a spindle motor for driving a hard disk.

[0002]

2. Description of the Related Art Maintaining cleanliness of a space outside a rotating machine is required in, for example, a hard disk drive. That is, in recent hard disk devices, the flying height of the magnetic head with respect to the hard disk surface is on the order of submicrons with further progress in miniaturization and large capacity. If dust or oil particles are scattered in the disk chamber of such a hard disk device, the surface of the hard disk or the magnetic head may be damaged. Therefore, it is necessary to keep the space outside the spindle motor in the disk chamber clean in order to prevent the damage. .

[0003] As one of the measures for this, a surface treatment such as rust prevention treatment is applied to a screw hole whose entrance is opened to the outside in a fixed column of a rotating machine, so that rust powder is scattered from the screw hole. This prevents inconveniences that may occur.

However, if the deep end of the screw hole is closed during the surface treatment, it is not easy to reliably perform the surface treatment over the entire screw hole, and the rust powder from the screw hole is not easily treated. Inconveniences such as scattering could not always be reliably prevented.

The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to provide an entire screw hole in which an entrance of a fixed column is opened to the outside. The reliability of the surface treatment effect over the surface of the rotating machine is increased, and the inconvenience such as scattering of rust powder to the outside of the rotating machine is effectively prevented.
An object of the present invention is to provide a rotating machine that can sufficiently maintain the cleanliness of the space outside the rotating machine.

[0006]

In order to achieve the above object, a rotating machine according to the present invention is a rotating machine having a fixed column having a screw hole whose entrance is open to the outside, and the rotating machine has a rotating shaft.
The axis of rotation, the axis of the fixed column, and the axis of the screw hole are aligned.
The entrance of the screw hole is aligned with the fixed column in the axial direction.
Open at the end, the back end of the screw hole and the inside of the rotating machine are fixed.
It communicates with the communicating part that opens on the side of the fixed pillar ,
Also, the screw holes are subjected to surface treatment such as rust prevention treatment ,
The communication portion is assumed to be sealed by a seal material .

[0007]

The inner end of the rotating machine and the back end of the screw hole whose entrance in the fixed column is open to the outside are open on the side of the fixed column.
Since the communication is performed by the communicating portion, the entire surface treatment of the screw hole can be performed reliably and easily. Therefore, the reliability of the effect of the surface treatment, that is, the rust prevention effect and the like is enhanced, and the inconvenience such as the scattering of rust powder to the outside of the rotating machine is effectively prevented. Also, rotate the back end of the screw hole.
The communication part that communicates with the inside of the press is sealed with a seal material.
From the entrance of the screw hole to the back end
Even if a screw is screwed in, the cut from the communication section to the inside of the rotating machine
Dust is prevented from being discharged, and the rotating
Oil particles and dust inside the screw hole entrance and its
It is more completely prevented from being led out. In addition,
If there is some trouble in the seal with the fly seal material
However, the communication between the inner end of the screw hole and the
Since it is inside the machine, it is cut by screwing into the screw hole
Powder scatters outside the rotating machine to clean the space outside the rotating machine
Impairing the performance is prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a half sectional view of a brushless spindle motor for driving a hard disk as an embodiment of the present invention.

Reference numeral 10 denotes a rotor hub on which a hard disk is externally fitted and fixed, and reference numeral 12 denotes an annular rotor magnet provided inside the outer peripheral wall of the rotor hub 10.

Reference numeral 14 denotes a fixing bracket. A fixed shaft 16 (fixed column) made of a ferromagnetic material protrudes from the center of the fixed bracket 14, and a stator core 18 is fixed to the outer periphery of the fixed bracket 14 so as to face the rotor magnet 12 with a radial gap therebetween. The stator coil 20 is wound around the stator core 18. Ball bearings 22 and 2 are provided on both sides of the fixed shaft 16 sandwiching the stator core 18.
The rotor 26 is rotatably supported via the ball bearings 22 and 24. 28 is
It is an annular bush fixed between the lower ball bearing 24 in the drawing and the outer peripheral wall of the rotor hub 10.

Reference numeral 30 denotes a lead wire of the stator coil 20, which is led out to the back side of the fixed bracket 14 through a lead hole 32 provided in the fixed shaft 16. 34
Reference numerals and 35 denote magnetic fluid seals provided on the outer side in the rotation axis direction of the two ball bearings 22 and 24.

Reference numeral 36 denotes an annular holder having a substantially L-shaped cross section.
38 is a pole piece, 40 is a permanent magnet, 42
Is a magnetic fluid magnetically held between the pole piece 38 and the outer peripheral surface of the fixed shaft 16. Reference numeral 44 denotes an annular protective cap for protecting the magnetic fluid seal 34. The annular holder 36 is fixed to the rotor hub 1 by the adhesive 45.
The protective cap 44 is fixed to the inner peripheral surface of the upper end portion and the inner peripheral surface of the lower end portion of the bush 28, and an adhesive 47 is attached to the inner peripheral side of the annular holder 36 on the outer side in the rotation axis direction of the magnetic fluid seal 34. It is fixed by.

A screw hole 46 whose axis coincides with the rotation axis of the motor is provided at an upper portion of the fixed shaft 16 in the drawing, and is opened above the fixed shaft 16. This screw hole 4
6 and the inside 48 of the motor are connected to a communicating portion 50.
And the communication part 50 is connected to the sealing material 5.
2 sealed. The surface of the screw hole 46 is subjected to a rust-proof treatment.

Since the inner end 48a of the screw hole 46 and the inside 48 of the motor communicate with each other through the communication portion 50,
The surface rust preventive treatment over the entire screw hole 46 is reliably performed. Therefore, the certainty of the rust prevention effect is increased, and inconvenience such as scattering of rust powder to the outside of the motor is effectively prevented.

Since the communicating portion 50 for communicating the inner end portion 46a of the screw hole 46 with the inside 48 of the motor is sealed by the sealing material 52, the screw is inserted from the entrance of the screw hole 46 toward the inner end portion 46a. Even if it is screwed in, the communication part 5
Discharge of chips and the like from 0 to the motor interior 48 is prevented,
Further, through the communication portion 50, oil fine particles, dust and the like in the motor interior 48 are more completely prevented from being led out to the entrance of the screw hole 46 and the outside thereof.

FIG. 2 is a sectional view of a main part of another brushless spindle motor for driving a hard disk according to an embodiment of the present invention. In this motor, a second annular surface 64 is provided further below and inside a first annular surface 62 provided below and inside an annular upper end surface of the rotor hub 60.
The base 68a of the annular holder 68 in the second annular surface 6
The adhesive 70 is applied over the upper side of the base 68a and the first annular surface 62 in the state of being located at 4, so that the annular holder 68 is fixed.

FIG. 3 is a cross-sectional view of a main part of another brushless spindle motor for driving a hard disk according to an embodiment of the present invention. In this motor, the rotor hub 80
An annular surface 84 is provided further inward and downward of the inclined surface 82 extending inward and downward from the inner edge of the annular upper end surface of the magnetic fluid seal 86. Upper side of 88a and inclined surface 8
The annular holder 88 is fixed by applying the adhesive 90 over the steps 2 and 3.

According to the structure shown in FIGS. 2 and 3, the bases 68a and 88 of the annular holders 68 and 88 are provided.
Since the seal withstand pressure at the portion a and the adhesives 70 and 90 is increased, the resistance to sudden environmental changes such as heat shock is improved.

FIG. 4 is a cross-sectional view of a main part of another brushless spindle motor for driving a hard disk according to an embodiment of the present invention. In this motor, the bent base 104a of the protective cap 104 is positioned on the annular step 102 provided inside the upper end of the rotor hub 100, and an adhesive 106 is applied on the bent base 104a to thereby protect the protective cap 104. Trying to fix it firmly.

Further, the outer diameter of the upper pole piece 108 is reduced to provide an annular gap between the pole piece 108 and the inner peripheral surface of the rotor hub 100, and an adhesive 110 is applied to the annular gap to thereby form the magnetic fluid seal 112. The fixation is strengthened.

FIG. 5 is a cross-sectional view of a main part of still another brushless spindle motor for driving a hard disk according to an embodiment of the present invention. In this motor, an inclined surface 122 inclined outward and downward is provided inside the upper end of the rotor hub 120,
By fitting the outer peripheral portion of the annular protective cap 124 having an elastic portion by bending the outer peripheral portion inside the inclined surface 122, and supporting the lower end of the bent portion 124 a of the protective cap 124 with the upper surface of the upper pole piece 126. The protective cap 124 is held. With such a configuration, the protection cap 124 can be easily provided. Note that, if necessary, the inclined surface 122 and the outer peripheral portion of the protective cap 124 may be bonded with an adhesive.

By cutting out the inner peripheral portion of the rotor hub 120 located outside the outer peripheral portion of the upper pole piece 126, an annular gap is provided between the outer peripheral portion of the upper pole piece 126 and the rotor hub 120. By applying the adhesive 128 to the gap, the magnetic fluid seal 13 can be formed.
2 is strengthening the fixation.

[0024]

According to the rotating machine of the present invention, since the inner end of the rotating machine is communicated with the inner end of the screw hole of which the entrance of the fixed column is open to the outside by the communicating portion, the entirety of the screw hole is covered. The certainty of the surface treatment effect is increased, and problems such as scattering of rust powder to the outside of the rotating machine are effectively prevented. The communication section
Since it is sealed with a sealing material, insert a screw into the screw hole.
Even if it is screwed in, the discharge of chips and the like from the communication
Is prevented and the oil inside the rotating machine is
Particles and dust are guided out of the screw hole entrance and outside.
Is completely prevented. Even if the seal material
If there are any obstacles in the
Since the inside of the hole communicates with the back end of the
Impairment of the cleanliness of the space outside the machine is prevented. This
Demonstrates excellent effect in maintaining the cleanliness of the space outside the rotating machine
Therefore, for example, in a case where it is necessary to maintain the cleanliness of the space outside the rotating machine , for example, when a hard disk as a recording medium is driven by being held on the outer peripheral portion of a rotor hub in a sealed disk chamber of a hard disk device. Optimal.

[Brief description of the drawings]

FIG. 1 is a half sectional view of a brushless spindle motor.

FIG. 2 is a sectional view of a main part of a brushless spindle motor.

FIG. 3 is a sectional view of a main part of a brushless spindle motor.

FIG. 4 is a sectional view of a main part of the brushless spindle motor.

FIG. 5 is a sectional view of a main part of the brushless spindle motor.

[Description of sign]

 16 Fixed shaft 46 Screw hole 46a Back end 48 Inside 50 Communication part 52 Sealing material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-121112 (JP, A) JP-A-1-61850 (JP, U) JP-A-1-116501 (JP, U) JP-A 4-116 80265 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 5/10 H02K 21/22

Claims (1)

(57) [Claims] 1. A rotating machine having a fixed column having a screw hole whose entrance is open to the outside, wherein a rotation axis of the rotating machine, an axis of the fixed column, and the screw hole are provided.
Are aligned, and the entrance of the screw hole is
An opening is provided at one end in the axial direction, and a deep end of the screw hole and the inside of the rotating machine communicate with each other through a communication portion that opens on a side surface of the fixed column. A rotating machine which has been subjected to processing and wherein the communication portion is sealed with a sealing material .