Negative pressure air bearing slider including negative...

Details Negative pressure air bearing slider including negative... Negative pressure air bearing slider including negative...

2001-04-02

2004-05-18

Davis, David (Department: 2652)

Dynamic magnetic information storage or retrieval

Head mounting

For shifting head between tracks

Reexamination Certificate

active

06738227

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a slider having a magnetic head installed thereon and floating at a predetermined height above a recording medium and, more particularly, to a negative pressure air bearing slider which maintains a stable float state by concurrently generating positive pressure and negative pressure.
2. Description of the Related Art
Magnetic recording/reproducing apparatuses such as hard disk drives include magnetic heads for recording and reproducing magnetic signals on and from a recording medium. As shown in
FIG. 1
, a magnetic head
10
is installed at a slider
20
provided at one end of a swing arm
30
. The magnetic head
10
moves to a desired track position above a disk (not shown) which is a recording medium as the swing arm
30
pivots, to perform recording or reproducing information.
In this case, the slider
20
staying on the surface of the disk begins lifting due to wind generated as the disk rotates. Since an end portion of the swing arm
30
where the slider
20
is installed is elastically biased toward the surface of the disk, when the disk stops rotating, the slider
20
lands on the surface of the disk.
The slider
20
can be lifted due to the pressure by the air entering between the surface of the disk and the slider
20
during the rotation of the disk with respect to the slider
20
. Since the air entering between the surface of the disk and the slider
20
during the rotation of the disk serves as a bearing, the slider
20
can be lifted and continuously float above the disk.
However, if only the positive pressure which lifts the slider
20
is continuously generated, the slider
20
is not maintained at the uniform height, but fluctuates unstably. Accordingly, a negative pressure bearing slider which generates negative pressure to pull the slider
20
toward the surface of the disk, concurrently with positive pressure, is widely adopted.
FIG. 2
shows the negative pressure air bearing slider
20
. As shown in the drawing, a plurality of rails
22
,
23
and
24
for generating positive pressure and negative pressure by air are provided at the slider
20
. Two front rails
22
are arranged at the front side of the slider
20
where air enters, forming an air inlet passage
21
interposed therebetween. A negative pressure rail
23
having a boomerang shape is formed at the rear side of the slider
20
. Space
28
formed between the front rails
22
and the negative pressure rail
23
is for generating positive pressure. Since the air inlet passage
21
between two front rails
22
is wider than each of air outlet passages
26
through which air is exhausted along the negative pressure rail
23
, the air stays in the space
28
. Thus, as the air is accumulated in the positive pressure space
28
, the pressure increases and affects the slider
20
. Reference numeral
24
denotes a rear rail where a magnetic head
27
is installed. Negative pressure space
25
is formed between both wings of the boomerang-shaped negative pressure rail
23
. The air in the negative pressure space
25
is exhausted together with air entering from the front side of the slider
20
, passing above the negative pressure space
25
, and exhausted toward the rear side of the slider
20
. However, since the negative pressure rail
23
serves as a barrier for entering of air from the front side, new air is difficult to enter the negative pressure space
25
. Thus, negative pressure is generated in the negative pressure space
25
. The horizontal surfaces of the rails
22
,
23
and
24
contribute to the generation of positive pressure. Consequently, the positive pressure generated by the positive pressure space
28
and the horizontal surfaces of the rails
22
,
23
and
24
and the negative pressure generated by the negative pressure space
25
make the slider
20
float at a predetermined height in a balanced state.
As shown in
FIG. 3
, an angle made by the lengthwise direction of the slider
20
and the tangential direction of a track t of a disk D is referred to as a skew angle &thgr;. Since the swing arm
30
pivots around a pivot shaft as shown in the drawing, the skew angle cannot be maintained to be zero (0) at all tracks. When the skew angle &thgr; occurs, since the slider
20
is not disposed to be symmetrical with respect to the input air, the amount of the air entering through the air inlet passage
21
and exhausted through the air exhaust passage
26
is much greater than that of the air passing above the negative pressure space
25
. That is, when the skew angle &thgr; is 0, the air entering the air inlet passage
21
is accurately collided with the middle portion of the negative pressure rail
23
and passes above the negative pressure space
25
. Otherwise, after colliding with the negative pressure space
25
, most air is exhausted through the air exhaust passages
26
. Then, since the flow of air which will take the air in the negative pressure space
25
becomes weak, so that the negative pressure in the negative pressure space
25
is lowered, the floating height of the slider
20
cannot be stably maintained. Furthermore, since the flow of air toward the rear rail
24
where the magnetic head
27
is installed is not smooth, the positive pressure of the rear rail
24
is lowered so that the slider
20
floats unstably.
When the air exhaust passage
26
is narrowed by making the horizontal surface of the negative pressure rail
23
large, to solve the above problem, although the amount of air exhausted through the air exhaust passage can be reduced, since the area contacting the disk increases, the slider
20
can be easily damaged due to friction with the disk when the disk begins and ends rotation. Thus, a slider having an improved structure which can prevent the exhaust of air in a large amount through the air exhaust passage, without increasing the contact area with the disk, is needed.
SUMMARY OF THE INVENTION
To solve the above problems, it is an object of the present invention to provide a negative pressure bearing slider having an improved structure so that the exhaust of air in a large amount through an air exhaust passage can be effectively reduced.
Accordingly, to achieve the above object, there is provided a negative pressure air bearing slider comprising a pair of front rails having a predetermined air inlet passage interposed therebetween at a front side of the slider where air enters, a negative pressure rail disposed at a rear of the front rails and forming air outlet passages connected to the air inlet passage, and forming a negative pressure space where negative pressure is generated according to a flow of air at a rear thereof, and a rear rail disposed at the rear of the negative pressure space, where a magnetic head is installed, in which a stepped portion protruding toward the air outlet passages is formed at the negative pressure rail.


REFERENCES:
patent: 5917679 (1999-06-01), Park et al.
patent: 5953181 (1999-09-01), Utsunomiya
patent: 6411468 (2002-06-01), Park et al.
patent: 6459546 (2002-10-01), Mundt et al.

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