JPS61133009A - Fluid bearing cylinder device - Google Patents

Abstract

PURPOSE:To prevent micro abrasion powder from entering a fluid bearing interior when a retainer is inserted and fixed and to improve reliability by setting a rotation shaft and a sleeve slip-off preventing mechanism to a fluid bearing exterior. CONSTITUTION:A disk 2 is fixed to the rotation shaft 1, and a sleeve 3 rotates coaxially with the rotation shaft 1 as an inner periphery, while the retainer 4 is held from the outside of the disk 2. The retainer 4 is fixed on the fixed disk 2 and the rotation shaft 1, which is inserted into the sleeve 3. The moment that the rotation shaft 1 is inserted, the tip projection of the leg of the retainer enters the groove interior in the outer periphery of the sleeve 3, however, the video spindle 1 and the sleeve 3 2ill not slip off because the projecting shape is approximately L-shaped. A thrust bearing member 5 is fixed at the bottom of the sleeve 3, and then the assembly of the fluid bearing is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydrodynamic bearing cylinder device that can be used in a video tape recorder. Background Art FIG. 2 is a sectional view of a conventional hydrodynamic bearing cylinder device. It shows.

To explain this, 21 is a rotating shaft with herringbone-type groups formed on the upper and lower sides of the outer periphery, 22 is a disk fixed to the rotating shaft 21, and 23 is a sleeve on which the rotating shaft 21 rotates coaxially on the inner periphery. , 24 is a thrust ring fixed to the shaft, and 25 is a thrust bearing member that has a groove formed by etching or the like and is attached to the bottom of the sleeve 23 at right angles to the axis of the sleeve 23. , 26 is a lubricant interposed in the minute gap between the sleeve 23 and the rotating shaft 21 and the minute gap between the thrust bearing member 26 and the end face of the rotating shaft 21.

The operation of the conventional fluid bearing cylinder device configured as described above will be described below.

When the rotating shaft 21 starts rotating by the motor, the rotating shaft 2
1, pressure is generated in the lubricant 26 due to the pumping action, and the rotation shaft 2
1 rotates stably without contacting the sleeve 23 and constitutes a radial bearing.

Furthermore, pressure is generated in the lubricant 26 in the spiral group of the thrust bearing member 26 due to the pumping action, causing the rotating shaft 21 to float in the direction of the arrow in FIG. 2, thereby forming a thrust bearing.

Problems to be Solved by the Invention However, in the above configuration, the thrust ring 24 is located inside the fluid bearing to prevent the sleeve 23 and the rotating shaft 21 from coming off.
When inserting and fixing into 1, thrust ring 24 and rotating shaft 2
1. Also, due to the friction between the thrust ring 24 and the insertion jig for the thrust ring 24, minute abrasion particles are generated, and as a result, the minute abrasion particles are mixed into the lubricant 26 of the thrust bearing and radial bearing, and the fluid bearing However, there was a problem that the specified performance could not be obtained.

In view of the above-mentioned problems, the present invention provides a highly reliable fluid bearing ring device that prevents minute abrasion particles from entering the fluid bearing.

Means for Solving the Problems In order to solve the above-mentioned problems, the hydrodynamic cylinder cylinder device of the present invention has a rotating shaft with herringbone-type groups formed above and below the outer periphery, and a rotating shaft fixed to the rotating shaft. In a hydrodynamic bearing that constitutes a radial bearing by a disk having an inner periphery and a sleeve that rotates coaxially with the rotating shaft on the inner periphery, a circumferential groove is formed on the outer periphery of the sleeve, and a circumferential groove is formed on the outer periphery of the sleeve. The retained retainer is ring-shaped and has one or more legs extending from the ring in the thrust direction, and an abbreviated protrusion extending in the circumferential direction is formed at the tip of the leg. By arranging the wave-stopping protrusion inside the groove of the sleeve, a mechanism for preventing the rotating shaft and the sleeve from coming off is set outside the fluid bearing.

Effect: With the above-described configuration, the present invention prevents minute abrasion particles caused by the friction between the retainer and other parts from entering the fluid bearing when the retainer is inserted and fixed, thereby realizing a highly reliable fluid bearing. It is something to do.

Embodiments Below A hydrodynamic bearing cylinder device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a sectional view of a fluid bearing cylinder device according to an embodiment of the present invention.

In Figure 1, 1 is a rotating shaft with herringbone-type groups formed on the upper and lower sides of the outer periphery, 2 is a disk fixed to the rotating shaft 1, and 3 is a rotating shaft with the rotating shaft 1 on the inner periphery, which rotates coaxially. The sleeve -4 is a retainer held from the outside of the disk 2, 5 is a spiral group processed by etching etc., and a thrust bearing is installed on the bottom of the sleeve 3 at right angles to the axis of the sleeve 3. A member 6 is a lubricant interposed in a minute gap between the sleeve 3 and the rotating shaft 1 and a minute gap between the thrust shaft member 6 and the end face of the rotating shaft 1.

The assembled blades of the hydrodynamic bearing device of this embodiment constructed as described above will be explained below with reference to FIG. 1. Since the operation is the same as that of the conventional example, the explanation here will be omitted. First, the retainer 4 is fixed to the disk 2 fixed to the rotating shaft 1, and then the rotating shaft 1 is attached to the sleeve 3.
″f: Insert.

At the same time as the rotary shaft 1 is inserted, the distal end protrusion of the retaining leg enters into the groove on the outer periphery of the sleeve 3. Since the protrusion has an oval shape, the rotating shaft 1 and the sleeve 3 cannot be removed.

The thrust bearing member 5 is fixed to the bottom surface of the sleeve 3, and the assembly of the fluid bearing is completed.

As described above, according to this embodiment, by setting a mechanism to prevent the rotating shaft and the sleeve from coming off on the outside of the hydrodynamic bearing, when the retainer is inserted and fixed, minute abrasion particles due to the friction between the retainer and other parts are removed. This prevents the fluid from entering the inside of the fluid bearing, thereby realizing a highly reliable fluid bearing.

In this embodiment, the disk 2 and the retainer 4 are fixed by means of an oval-shaped protrusion, but they may be fixed with screws.

Effects of the Invention As described above, the present invention provides a mechanism for preventing the rotating shaft and sleeve from coming off outside the hydrodynamic bearing, thereby preventing minute abrasion particles caused by the friction between the retainer and other parts when inserting and fixing the retainer. This prevents the fluid from entering the inside of the fluid bearing and realizes a highly reliable fluid bearing.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hydrodynamic bearing cylinder device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional hydrodynamic bearing cylinder device. 1... Rotating shaft, 2... Disc, 3...
... Sleeve, 4... Retainer, 6...
...Thrust bearing member, 6...Lubricant. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
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Claims (1)

[Claims] In a hydrodynamic bearing that constitutes a radial bearing with a rotating shaft forming a herringbone type group on the upper and lower outer periphery, a disk fixed to the rotating shaft, and a sleeve on which the rotating shaft rotates coaxially on the inner periphery. A circumferential groove is formed on the outer circumferential side of the sleeve, and the retainer, which is held from the outside of the disk, is ring-shaped and has one or more legs extending from the ring in the thrust direction, and has one or more legs at the tips of the legs. It has a substantially L-shaped protrusion in the circumferential direction, and by arranging the retaining protrusion inside the groove of the sleeve, a mechanism for preventing the rotating shaft and the sleeve from coming off is set outside the fluid bearing. A fluid bearing cylinder device characterized by: