JPS6032430Y2 - Spindle holding structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spindle holding structure, and more particularly to a spindle holding structure in which preloading of the spindle in the radial direction is performed using an easily machined structure.

In recent years, as the capacity of magnetic disk devices has increased, the track density of the disks has tended to increase.

As described above, as the track density increases, the spindle whirling phenomenon causes off-track during R/W by the magnetic head, making it impossible to perform normal R/W operation.

In order to prevent such whirling of the spindle, an ultra-precision spindle is usually used, and the whirling can be reduced to submicron (
1/100017DI) or less.

However, when a bearing is fitted into a spindle and attached to a housing, the clearance due to the tolerance of the outer ring of the bearing and the tolerance of the inner diameter of the housing is usually several microns to several tens of microns, which requires advanced technology and many man-hours for machining, making it extremely expensive. Become.

Furthermore, whirling of the spindle cannot be completely prevented.

Conventionally, methods to prevent this kind of spindle whirling have been to apply belt-driven loads in a direction that has less influence on the theta direction of the magnetic head, that is, in a direction perpendicular to the belt drive, or to use built-in motor type spindles or rotating In the case of a type actuator, the outer ring of the bearing that fits into the spindle is pressurized from the outside by a spring to prevent whirling.

Figure 1 shows a conventional structure for applying radial preload to a bearing.

In the figure, 1 is the spindle, 2, 2 is the bearing, and 3 is the spindle.
4 is a housing, 4 is a stator (coil), and 5 is a loader (magnet), which is an example of a so-called built-in spindle.

In such a structure, when the spindle 1 is rotated, the outer ring of the bearing 2' is usually fixed and the bearing 2 needs to be preloaded, so the distance between the housing 3 and the outer ring of the bearing 2 is set to be several microns to several 10 microns so that the outer ring can slide. Because of the clearance, the spindle 1 oscillates.

In order to prevent whirling occurring in the spindle 1, a hole 7 is provided at one location in the fitting portion of the housing 3 with the bearing 2 toward the center of the bearing 2, and a radial spring 8 is provided in the hole to apply pressure.

As another example, a method has been used in which a notch 9 is provided and a radial spring (plate spring) 10 is provided in the notch to apply pressure.

However, the hole 7 for installing the radial spring 8 or 10
Alternatively, there is a problem that providing the notch 9 is not preferable in terms of processing man-hours and accuracy.

The present invention was devised in view of the above-mentioned problems, and its purpose is to provide a spindle holding structure that is easy to process, does not require dimensional accuracy, and can accurately apply preload in the radial direction. It's about doing.

In order to achieve the above object, the present invention is characterized in that, in a structure that holds a direct drive spindle of a magnetic disk drive, there is a An O-ring groove is provided in the groove, and an O-ring provided with a spherical or cylindrical bulge or a rotatable spherical, annular or other elastic body is inserted into the IWU position of the groove.

An embodiment of the present invention will be described below with reference to the drawings.

2A and 2B are sectional views showing a spindle holding structure according to the present invention, in which FIG. 2A shows a side sectional view and FIG. 2B shows a planar sectional view.

In relation to FIGS. 2A and 2B, a groove 13 into which an O-ring is inserted is provided along the inner diameter of the housing 3 in contact with the bearing 2 fitted to the spindle 1, and a spherical bulge ( hump) or rotatable spherical elastic body 1
Insert the 0'IJ ring 11 provided with 2.

The thickness of the circular part of the O-ring 11 is made smaller than the width of the groove 13, and the diameter of the bulge (bump) or rotatable spherical elastic body 12 is made slightly larger than the width of the groove 13.

The above-mentioned bulge (bump) or rotatable spherical elastic body 12
When the O-ring provided with the O-ring is inserted into the groove 13, the bulge or spherical elastic body 12 pressurizes the bearing 2 with a force that tends to push it out of the groove.

The circumferential length of the circular portion of the O-ring is larger than the circumferential length of the groove 13, and the O-ring is compressed and inserted into the groove 13, and is held by the force of outward expansion to prevent it from rotating within the groove.

In this way, the groove 13 is provided in the housing 3, and the bearing 2
A bulge (bump) or a rotatable spherical elastic body 12 is inserted between the O-ring 11 at the l location, and the bearing 2 is pressurized by the bulge or spherical elastic body 12, thereby adjusting the outer ring tolerance of the bearing 2. Even if there is a certain clearance in the inner diameter tolerance, since the spindle 1 is always pressed in one direction, whirling around during rotation of the spindle 1 can be prevented.

As explained above, with the spindle holding structure according to the present invention, there is an air gap between the housing 3 and the outer ring of the bearing 2.
A bulge or spherical elastic body 12 is provided at one location on the ring, and the bulge or spherical elastic body presses the outer ring of the bearing, thereby making it possible to accurately apply preload in the radial direction.

Further, since precision is not required in machining the O-ring groove for applying preload, its practical effects are extremely large.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing a conventional structure that applies radial preload to a bearing, Figure 2 A is a side sectional view showing the spindle holding structure of the present invention, and Figure 2 B is a plan sectional view of Figure 2 A. be. In the figure, 1 is a spindle, 2 and 2' are bearings,
3 is a housing, 4 is a stator (coil), 5 is a rotor (magnet), 7 is a hole in the center direction, 8 is a radial spring, 9 is a notch, 10 is a leaf spring, 11 is an O-ring, 12
indicates a bulge (bump) or a spherical elastic body, and 13 indicates an 01J groove.

Claims (1)

[Claim for Utility Model Registration] In a structure for holding a direct drive spindle of a magnetic disk, a groove along the circumference is provided on the inner wall of the housing at a position where the outer ring of a bearing attached to the spindle and the housing fit together. , a spindle holding structure constructed by inserting an O-ring partially bulged into the groove.