JPS63146399A - Static electricity by-passing mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for bypassing static electricity charged on a rotating body used in electronic equipment and the like.

[Prior Art] A rotating body that is supported by a bearing and rotates at high speed is electrically insulated from a stationary side by the oil film of the bearing, so that the rotating body is charged with static electricity. This static electricity causes a discharge phenomenon, and the noise generated at this time causes malfunctions in electronic circuits. As a countermeasure to this problem, a static electricity bypass mechanism has been devised that discharges static electricity charged on the rotating body.

Conventionally, this type of static electricity bypass mechanism is shown in FIGS. 3 and 4.
As shown in the figure, a shaft-shaped rotating body 5 of a spindle motor 4
A pole 7 is rotatably attached to the tip of the pole 7, and a sliding piece 10 that contacts the pole 7 is arranged below the pole 7, and the sliding piece 10
It has a structure in which it is biased and supported by a leaf spring 11 attached to a printed circuit board 9. As a result, the static electricity charged on the rotating body 5 is stored in the pole 7, and the sliding piece 10 and the leaf spring 11
was discharged to the printed circuit board 9 via.

[Problems to be Solved] The above-described conventional static electricity bypass mechanism has a structure in which the sliding piece 10 is biased and supported by the leaf spring 11, so the sliding movement is caused by contact friction between the ball 7 and the sliding piece 10. There was a drawback that the piece 10 caused resonance and generated sound. Another drawback is that the leaf spring 11 is large compared to the chip and requires a large space.

[Means for solving problems] The present invention has been made to solve the above-mentioned conventional problems, and as a means for solving the problems, the tip of the rotating body is brought into contact with a sliding piece fixed on the non-rotating side. In the static electricity bypass mechanism for discharging static electricity charged in the rotating body, a cavity opening at the tip is formed at the tip of the rotating body, and a spherical shape that rotates in contact with the sliding piece is formed in the opening of the cavity. The present invention provides an electrostatic bypass mechanism in which a biasing member for biasing the spherical body toward the sliding side is provided in the cavity.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of a magnetic disk drive equipped with an electrostatic bypass mechanism according to an embodiment of the invention, and FIG. 2 is a sectional view showing the electrostatic bypass mechanism according to an embodiment of the invention.

As shown in FIG. 1, an electrostatic bypass mechanism 1 is provided in a spindle motor 4 that rotates a magnetic disk 3 of a magnetic disk device 2. As shown in FIG.

As shown in FIG. 2, the static electricity bypass mechanism 1 is provided at the tip of a shaft-like rotating body 5 of a spindle motor 4, and has a cavity 6 that opens at the tip and is fitted into the opening of the cavity 6. a ball 7; a ball 7 provided within the cavity 6;
It is composed of a spring 8 that biases and supports the ball 7, and a sliding piece 10 that contacts the ball 7 and is fixed to the printed circuit board 9.

The cavity 6 is formed in a cylindrical shape coaxial with the rotating body 5, and its opening is located at the tip of the rotating body 5.

The ball 7 has a diameter that is approximately the same as the diameter of the cavity 6,
It is rotatably fitted into the opening of the cavity 6 with the lower hemisphere exposed to the outside.

The spring 8 is a small spiral spring. The spring 8 is mounted in the cavity 6 with its upper end in contact with the upper surface of the cavity 6 and its lower end in contact with the upper hemisphere of the ball 7. This allows the ball 7 to be moved from above to the sliding piece 10.
It biases the ball 7 to the side and elastically supports the upward movement of the ball 7.

The sliding piece 10 is fixed to the printed circuit board 9, and its upper surface is in contact with the lower end of the ball 7.

When the rotating body 5 of the spindle motor 4 rotates, static electricity is generated on the rotating body 5, but this static electricity is absorbed by the ball 7 with a small curvature.
is mostly charged. Since the ball 7 is rotating in contact with the sliding piece 10 connected to the printed circuit board 9, the static electricity charged on the ball 7 flows out to the printed circuit board 9 via the sliding piece 10.

At this time, even if the sliding piece 10 wears out or the distance between the spindle motor 4 and the printed circuit board 9 changes, the ball 7 always contacts the sliding piece 10 to eliminate static electricity within the rotating body 5. It is discharged onto the substrate 9.

[Effects of the Invention] As explained above, the present invention forms a cavity opening at the distal end of a rotating body, and a spherical body that rotates in contact with a sliding piece is provided in the opening of the cavity. Since the biasing member for biasing the spherical body toward one side of the sliding body is an electrostatic bypass mechanism provided in the cavity, generation of resonance noise can be prevented and the size of the electrostatic bypass mechanism itself can be reduced. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a side view of a magnetic disk drive equipped with an electrostatic bypass mechanism according to an embodiment of the present invention, FIG. 2 is a sectional view showing the electrostatic bypass mechanism of this embodiment, and FIG. 3 is a conventional electrostatic bypass mechanism. FIG. 4 is a diagram showing the electrostatic bypass mechanism of FIG. 3 viewed from below. 1: Static electricity bypass mechanism 5: Rotating body 6: Cavity 7: Ball 8/spring (biasing member) 9 Niblint board (non-rotating side) 10: Sliding piece

Claims (1)

[Scope of Claims] In an electrostatic bypass mechanism for discharging static electricity charged on the rotating body by bringing the tip of the rotating body into contact with a sliding piece fixed on the non-rotating side, the tip of the rotating body has an opening at the tip. form a cavity that
A spherical body that rotates in contact with the sliding piece is provided in the opening of the cavity, and a biasing member that biases the spherical body toward one side of the sliding part is provided in the cavity. Electrostatic bypass mechanism.