JPH03255214A - Fluid bearing device - Google Patents

Abstract

PURPOSE:To accomplish the quality improvement, miniaturization, weight, reduction and remarkable cost reduction of the device by fixing the thrust pad and the sleeve of the fluid bearing of a rotating head cylinder by press-fitting a ring-shaped member. CONSTITUTION:A shaft 2 and a sleeve 3 which have been fixed by pressure fitting or shrinkage fitting are insertedly fitted in a lower drum 1, and a thrust pad 4 being abutted on the end surface 2a of the shaft or being indirectly in contact with it via oil is fixed to the sleeve by using a ring-shaped member 6 made up of a sheet metal or resin or the like, in other words the thrust pad and the sleeve of a thrust fluid bearing are fixed by pressure-fitting the ring- shaped member, thus the in quality improvement, miniaturization weight lightening, and remarkable cost reduction of the device can be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydrodynamic bearing device that can be used in a rotary head drum device of a video tape recorder and a rotary recording type digital audio tape recorder.

BACKGROUND OF THE INVENTION FIG. 3 is a sectional view of a rotary head drum device using a conventional hydrodynamic bearing device. 1 is a fixed drum for guiding the magnetic tape; 2 is a fixed drum having a spherical or flat end surface 2a and two herringbone-shaped groups 2b processed by etching or the like on the upper and lower outer peripheral surfaces in the axial direction; 1
The shaft is coaxially press-fitted into the center of the 3
2 is a sleeve that is rotatable coaxially with respect to the shaft 2 and has a bearing surface 3a; 4 is a thrust receiver fixed to the upper end of the sleeve 3; 20 is one or more pieces that fix the thrust receiver 4 and the sleeve 3; For the thrust receiver, use the fixing screw, 5
is a lubricant present in the minute gap between the herringbone groove 2b and the bearing surface 3a and the minute gap between the end surface 21L of the shaft 2 and the thrust receiver 4.

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

When the rotating part including the sleeve 3 of this hydrodynamic bearing device rotates, the centripetal nature of the rotating part is maintained by the pumping action of the hydrodynamic bearing composed of the herringbone group 2b, the bearing surface 31L, and the lubricant 5. shaft 2
The pivot bearing constituted by the end face 2a, the thrust receiver 4, and the lubricant 5 supports the load in the cis-thrust direction and maintains normal rotation.

Problem to be Solved by the Invention However, in the above configuration, since the thrust receiver 4 is fixed with a screw 20, it is necessary to provide a tap 21 for a fixing screw on the sleeve 3. It is difficult to reduce the size and weight of the device, and it requires a plurality of taps and screws, making it expensive.

In view of the above problems, the present invention provides a hydrodynamic bearing device in which a thrust receiver is fixed without using screws.

Means for Solving the Problems In order to solve the above-mentioned problems, the hydrodynamic bearing device of the present invention provides a thrust bearing for making contact with the spherical or flat end surface of the shaft or floating the oil in groups. A ring-shaped member is press-fitted into the thrust receiver and the outer peripheral end face and side surface of the sleeve to fix the thrust receiver.

Function: By fixing the thrust receiver with a ring-shaped member, the present invention makes it possible to reduce the size and weight of the sleeve, and at the same time, it is possible to rationalize the hydrodynamic bearing.

Embodiment Hereinafter, a hydrodynamic bearing device according to an embodiment of the present invention will be explained with reference to FIGS. 1 and 2. 3 in FIG. 1, the same members as those in the conventional example shown in FIG. 3 are given the same numbers and detailed explanations will be omitted.

FIG. 2 is an exploded perspective view of the main parts. Shaft 2 and sleeve 3 fixed to lower drum 1 by press fit or shrink fit
A ring-shaped member 6 made of sheet metal, resin, etc. is used to insert the thrust receiver 4, which is in contact with the end surface 2a of the shaft or is in indirect contact with the end surface 2a of the shaft, through oil. A ring-shaped member 6 is uniformly press-fitted into the outer peripheral end surface and side surface 3b of the receiver 4 and the sleeve 3 under optimal conditions to fix the thrust receiver 4.

With this configuration, one or more thrust receivers were conventionally fixed with the fixing screws 20, but the thrust receivers can be fixed in one process, and at the same time, the thrust receivers can be fixed with the fixing screws 20. One or more taps 21 that were required for this purpose are also no longer required. and said tap 2
The spacer of the tap that was required in step 1 is no longer necessary, and there is an advantage that this problem can be solved, although it was difficult to remove cutting chips using a conventional tap. The ring-shaped member 6 has a ring-shaped cap shape, but only the ring-shaped part that presses the thrust receiver has a protrusion like that shown in 6a in Fig. 2 O). A similar effect can be obtained by press-fitting or the like. In short, it is sufficient to have a structure that securely holds the slanut plate so that it does not move by press-fitting.

Effects of the Invention As described above, the rotating hekudo cylinder of the present invention has a rotating head configured to extremely easily fix the thrust receiver of the fluid bearing and the sleeve by press-fitting a ring-shaped member and to ensure highly accurate installation. Since it is a cylinder device, the conventional tapping work on the end face of the sleeve and the screw fastening work for fixing the thrust receiver and the sleeve can be eliminated, and in particular, the present invention improves the quality of the rotating head cylinder, makes it smaller and lighter, and reduces the cost. This is extremely advantageous in practice because it can be reduced.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a rotary head cylinder according to an embodiment of the present invention, Fig. 2 (&) is an exploded perspective view of its main parts,
FIG. 3B is a perspective view showing another shape of the ring-shaped member 6, and FIG. 3 is a sectional view of a conventional rotating cylinder.

Claims (1)

[Claims] a hydrodynamic fluid bearing consisting of a plurality of bearing surfaces provided on the outer peripheral surface of a shaft and the inner peripheral surface of a sleeve rotatable coaxially with the shaft; and a thrust receiver fixed to the spherical end surface of the shaft and the end surface of the sleeve. A hydrodynamic bearing or a thrust bearing consisting of a pivot bearing, or a hydrodynamic bearing device configured to provide a group on the shaft end surface to levitate the thrust and the shaft end surface, the thrust bearing and the outer peripheral end surface and side surface of the sleeve. A hydrodynamic bearing device characterized in that a ring-shaped member is press-fitted to fix a thrust receiver.