JPH04302860A - Spindle motor - Google Patents

Abstract

PURPOSE:To interchange only parts such as parts having flaws caused by a frame or a rotor and parts which are distorted, etc., by constituting plural interchangeable parts in a circular shape with a center of each shaft of the frame and the rotor. CONSTITUTION:The spindle motor 10 possesses the frame 11 to be fitted to a disk device A, the shaft 12 erected on the frame 11 and the rotor 14 provided freely rotatably on the shaft 12 by bearings 13 and 13. A stator 15 is provided in the frame 11. The frame is composed of a shaft supporting part 111 press- fitted or integrally formed with the shaft 12, and a fitting part 112 to be fitted to the disk device A. The fitting part 112 is a ring shape, into which the shaft supporting part 111 is press-fitted. For example, when the fitting part 112 of the frame 11 is distorted, the fitting part 112 is removed from the shaft supporting part 111, and can be interchanged with other fitting part 112 of nondistortion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor generally called a spindle motor used mainly for rotating a disk (magnetic disk, optical disk), etc.

0002

[Prior Art] Conventionally, this type of motor (not shown)
It has a frame that is attached to the disk device, and a rotor that is rotatably mounted on a shaft that is erected on the frame with a bearing. A disk is attached to the rotor. Further, the rotor is provided with a plurality of mounting holes for the disk holding cap. Since this spindle motor is used in a disk device, it requires high performance, strict dimensional control of each component, and smooth rotation of the rotor.

0003

However, such a spindle motor has the following problems. ■If the frame or rotor is damaged, if distortion is discovered during inspection, or if the dimensions are not within specified tolerances, the frame or rotor must be replaced. The entire rotor must be replaced, which increases costs. ■When machining the mounting holes of the disk holding cap, if the wall thickness between the hole and the hole into which the bearing is inserted (for example, the part indicated by reference numeral 20 in Fig. 2) is thin, this part will be cut by the number of mounting holes. , may protrude into the hole into which the bearing is inserted. For this reason, the outer ring of the bearing that is later inserted may be deformed and a protruding portion may be formed in the outer ring due to the protruding portion. Therefore, if the number of mounting holes and the number of rotating elements of the bearing are the same or different by one or so, all the rotating elements may ride on the protrusion in the outer ring almost simultaneously, and the rotor may not move smoothly. rotation is prevented, making it impossible to obtain high performance.

0004

[Means for Solving the Problems] First, the present invention includes a frame attached to a disk device, and a rotor rotatably mounted on a shaft erected in the frame by a bearing and to which a disk is attached. In the spindle motor in which the rotor has a plurality of mounting holes for disk holding caps, at least one of the frame and the rotor may be configured of a plurality of circular replaceable parts centered on the shaft. Second, the method comprises a frame to be attached to a disk device, a rotor rotatably provided on a shaft erected in the frame by a bearing and to which a disk is attached, and a disk holding cap is attached to the rotor. In a spindle motor having a plurality of holes, the above problem is solved by a configuration in which the number of the mounting holes is two or more different from the number of rotating elements of the bearing.

[0005]

[Operation] The rotor or frame can be divided into an inner part and an outer part of the circle with the axis as its center. Therefore, parts of the inner part or the outer part can be replaced. In addition, since the mounting holes of the disk holding cap are formed with a difference of two or more points from the number of rotating elements of the bearing, there is no possibility that all the rotating elements may ride on the protrusion inside the outer ring of the bearing at the same time. There isn't.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. The spindle motor 10 has a frame 11 attached to the disk device A, a shaft 12 erected on the frame 11, and a rotor 14 rotatably mounted on the shaft 12 by bearings 13, 13.

A stator 15 is provided on the frame 11 . The frame 11 is composed of a shaft support part 111 into which the shaft 12 is press-fitted or integrally molded, and a mounting part 112 to be mounted on the disk device A. The mounting portion 112 is ring-shaped and is press-fitted into the shaft support portion 111. The press-fitted portion has a circular shape centered on the shaft 12. Note that screw engagement may be used instead of press fitting.

The bearing 13 (see FIG. 2) has inner and outer rings 1
31, 132 and eight balls 133 (rotating elements). Note that the bearing 13 is a ball 133
A bearing using rollers (not shown) may be used instead.

A cylindrical magnet 16 is provided on the inner periphery of the rotor 14, and a plurality of disks D are mounted on the outer periphery. Therefore, the rotor 14 rotates together with the disk D due to the magnetic action of the stator 15 and the magnets 16. The rotor 14 is composed of a magnet mounting part 141 into which the magnet 16 is fitted, and a disk mounting part 142 into which the disk D is mounted.The magnet mounting part 141 is ring-shaped and is press-fitted into the disk mounting part 142. has been done. The press-fitted portion has a circular shape centered on the shaft 12. Note that screw engagement may be used instead of press fitting. Further, the rotor 14 has five screw holes (attachment holes) 18 (see FIG. 2) formed at equal intervals for attaching a cap 17 for holding the disk D. In this case, the number of screw holes 18 is three fewer than the number of balls 133.

Therefore, if the frame 11 or rotor 14 is damaged during assembly, if distortion is discovered during inspection, or if the dimensions are not within predetermined tolerances,
Just replace that part. For example, if the mounting part 112 of the frame 11 is distorted, remove the mounting part 112 from the shaft support part 111 and replace it with another mounting part 1 without distortion.
Just replace it with 12.

Furthermore, if there is a change in the specifications of the spindle motor 10, each part may be replaced in accordance with the change. For example, if there is a change in the number of disks D installed,
It is sufficient to replace it with another disk mounting portion 142 having a different length. Therefore, the magnet 16 and the magnet attachment part 141 can be used in common. This also applies to the frame 11. Alternatively, the part to be press-fitted into the shaft 12 may be made into a unit and manufactured in advance, and other parts may be assembled into this unit as needed.

Furthermore, the screw hole 18 is a female thread formed in a pilot hole formed in the rotor 14 by tapping. Therefore, when machining the screw hole 18, a portion between the bearing press-fit hole 19 into which the bearing is press-fitted and the screw hole 18 (the portion indicated by the reference numeral 20) protrudes into the bearing press-fit hole 19, and a protrusion 21 is generated. Something happens. Therefore, a protrusion (not shown) is formed by the protrusion 21 on the inner surface of the outer ring 132 of the bearing 13 that will be inserted later, and the balls 133 ride on the protrusion and then pass through while the rotor 14 is rotating. Become. However, since the number of screw holes 18 is three fewer than the number of balls 133, all balls 133
There is no possibility that the protrusions 20 will ride on all the protrusions 20 at the same time. Therefore, the smooth rotation of the rotor 14 is not hindered.

In FIG. 2, a gap S is provided between the outer ring 132 and the bearing press-fit hole 19, but this is exaggerated in order to make the explanation easier to understand. In reality, the protrusion 21 and the outer ring 132 are deformed, and the gap S becomes almost nonexistent.

[0014]

[Effects of the Invention] The spindle motor of the present invention provides the following effects. (2) In the invention of claim 1, only the damaged or distorted portions of the frame or rotor can be replaced. Furthermore, if there is a change in the specifications of the spindle motor, only that part can be replaced, and the other parts can be used as common parts. (2) In the invention of claim 2, all the rotating elements do not ride on the protrusion that protrudes into the outer ring of the bearing at the same time due to the protrusion that is generated when drilling the mounting hole.
The rotor can rotate smoothly.

[Brief explanation of drawings]

FIG. 1 is a sectional view taken along the axis of a spindle motor of the present invention, and is also a sectional view taken along arrow 1-1 in FIG.

FIG. 2 is a plan view of the rotor with bearings press-fitted therein.

[Explanation of symbols]

A Disk device D Disk 10 Spindle motor 11 Frame 12 Shaft 13 Bearing 14 Rotor 17 Cap (disc holding cap) 18
Screw hole (mounting hole) 133 Ball (rotating element)

Claims (2)

[Claims] 1. A frame that is attached to a disk device, and a rotor that is rotatably mounted on a shaft that is erected in the frame by means of a bearing and to which a disk is attached, the rotor having an attachment hole for a disk holding cap. What is claimed is: 1. A spindle motor in which a plurality of rotors are formed, wherein at least one of the frame and the rotor is constituted by a plurality of circular replaceable parts centered on the shaft. 2. A frame that is attached to a disk device, and a rotor that is rotatably mounted on a shaft that is erected in the frame by a bearing and to which the disk is attached, and the rotor is provided with an attachment hole for a disk holding cap. 1. A spindle motor in which a plurality of mounting holes are formed, the number of the mounting holes being two or more different from the number of rotating elements of the bearing.