JPS6252780A - Spindle - Google Patents

Abstract

PURPOSE:To watch the splash of a magnetic fluid and to test the splash of the magnetic fluid generating in the assembling of a spidle by using a transparent material between the spindle and a shaft. CONSTITUTION:A ring-shaped yoke 7 interposing a ring-shaped magnet 8 to face with a shaft 1 is provided at a housing 3, and a magnetic fluid 9 is poured between the yoke 7 and the shaft 1. The above constitution is the same as the conventional one, however, in the constitution, a transparent plastic ring 10 is inserted with pressure or sticked and fixed between the spindle hub 2 and the shaft 1. The accuracy of the spindle is not reduced even when the plastic ring 10 is interposed between the spindle hub 2 and the shaft 1, and especially, a fact that the coefficient of linear expansion of plastic is larger than that of metal, though it is the fault of the plastic, only affects the size of the outer diameter of the hub 2 because it is formed in a ring shape, not affecting the rotation accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spindle used in a magnetic disk device or the like (hereinafter simply referred to as the device) for rotating a disk at high speed and steadily.

[Conventional technology]

Conventionally, this type of spindle was manufactured by press-fitting a shaft 1 into a hub 2 and arranging a ball bearing 4 into a housing 3 as shown in FIG.
Preload is added to Dg-le bearing 4 with preload sill 5. The ball bearing 4 on the stone gear 6 side is fixed by press-fitting the stone gear e-6 into the shaft 1.

Since this type of spindle is mainly used in magnetic disk drives, an air seal is provided with magnetic fluid to prevent grease and grease vapor generated from the gill bearing 4, as well as air from outside the device case from entering the device. has been done. FIG. 2 is an enlarged view of the magnetic fluid part of the spindle. To explain FIG.
, the magnet 8 and the yoke 7 constitute a magnetic circuit. As a result, by introducing the magnetic fluid 9 into the minute gap between the shaft 1 and the yoke 7, the magnetic fluid 9 remains between the shaft 1 and the yoke 9 without scattering even when the shaft 1 rotates. In this way, air can be blocked between the shaft 1 and the yoke 7 despite the rotational movement of the shaft 1.

[Problem that the invention seeks to solve]

Since the above-mentioned conventional spindle uses magnetic fluid, if the magnetic fluid were to be scattered during assembly, it could not be confirmed that the magnetic fluid had been scattered. As a result, the magnetic fluid inside the spindle hub is scattered to the outside of the spindle knob as the spindle rotates, and in the case of magnetic disk drives, this can lead to serious accidents such as collision between the magnetic disk and the magnetic head. The present invention solves the above-mentioned problems and provides a spindle in which scattering of magnetic fluid can be visually observed.

[Means for solving problems]

The present invention provides a spindle in which a ring-shaped yoke sandwiching a ring-shaped magnet is installed in a housing so as to face the shaft, and in which a magnetic fluid is poured between the yoke and the shaft. This is a spindle characterized by being provided with a ring.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, a ring-shaped yoke 7 sandwiching a ring-shaped magnet 8 is installed in the housing 3 so as to face the shaft 1, and a magnetic fluid 9 is poured between the yoke 7 and the shaft 1. The configuration is the same as before. In the present invention, a transparent plastic ring 10 is press-fitted or adhesively fixed between the spindle knob 2 and the shaft 1 as shown in the figure.

4 is the goal bearing, 5 is the preload spring, 6 is the
is Stotsunoku.

In the present invention, even if the transparent plastic ring 10 is interposed between the spindle knob 2 and the shaft 1, the precision of the spindle does not deteriorate, and the ring shape also overcomes the disadvantage of plastics, in particular that their coefficient of linear expansion is larger than that of metals. Therefore, it only affects the size of the outer diameter of the knob 2 and does not affect the rotation accuracy at all.

〔Effect of the invention〕

As explained above, the present invention has the advantage that by using a transparent material between the spindle knob and the shaft, the scattering of magnetic fluid can be visually observed, and the scattering of magnetic fluid that occurs when assembling the spindle can be inspected. There is.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3, which is a partially enlarged view of the figure, is a sectional view showing a conventional example. 1...Shaft, 2...Hub, 3...Housing, 10...Transparent glass ring. Figure 2

Claims (1)

[Claims] (1) In a spindle in which a ring-shaped yoke sandwiching a ring-shaped magnet is installed in a housing so as to face the shaft, and a magnetic fluid is poured between the yoke and the shaft, there is a space between the hub of the spindle and the shaft. A spindle characterized by a transparent ring.