JPS60220218A - Liquid bearing device - Google Patents

Abstract

PURPOSE:To prevent a scattering of a lubricant due to a vibration by providing a spiral groove at an end of a shaft or a thrust receiving member, and providing a ring forming a clearance between itself and a periphery of the fixed shaft. CONSTITUTION:The thrust receiving member 21 is abutted against the end surface 18A of the fixed shaft 18, and is secured to the end surface of a sleeve 20A. The spiral groove 33 is provided at a portion where the end surface 18A of the shaft is abutted against the thrust receiving member 21, and the lubricant 36 is retained between the thrust receiving member 21 and the end surface 18A. A ring 27 which is rotated together with the disk 20, while in contact with the thrust receiving member 21, a ring 27 which rotates with the disk 20 is provided between the disk 20 and the fixed shaft 18, thereby making it difficult to scatter the lubricant 36.

Description

[Detailed description of the invention] Industrial applications 2・7 The present invention relates to a hydrodynamic bearing device using a lubricant.

1 to 3 show the structure of an example in which a conventional hydrodynamic bearing device is applied to a rotating head device of a video tape recorder (hereinafter referred to as a VTR cylinder). In the figure, a fixed shaft 1 is press-fitted into the center of the lower cylinder 2, and a disk 3 is rotatably inserted into the fixed shaft 1.
The upper part has a thrust receiver 4, an upper cylinder 5, and a magnetic helad e. A rotary lance 7 is attached to the lower part of the disk 3 to transmit the video signal taken out from the magnetic tape to the fixed side via a rotating magnetic head 6. A fixed-side rotary i-lance 8 for receiving the video signal is attached to constitute a rotating-side unit 10.

Further, a C ring 9 shown in FIG. 3 is fixed to the tip of the fixed shaft 1 to prevent the rotating unit 10 from being pulled out.

Further, an armature magnet 113 of a direct drive type motor is further attached to the disc 3, and a fixed side coil unit 12 is attached to the lower cylinder 2 opposite to it.
This constitutes a direct drive motor 13. The armature magnet 11 always attracts the stationary coil unit 12 with a force of 600 to 900 grams.

Note that radial groups 14A are formed at two locations on the upper and center portions of the fixed shaft 1 by etching or the like.

14B is machined, and the tip surface 1A of the fixed shaft 1 is precisely machined to be flat and at right angles, and a single row as shown in FIG. The spiral group 16 is processed by etching or the like. Since lubricant is applied to each of the group parts 14A, 14B, and 1503 locations, the motor 13 drives the rotating unit 10.
When the unit 10 is rotated, pressure is generated by the pumping action of the three group parts, and the rigidity of the oil film increases, so that the rotating unit 10 completely floats relative to the fixed shaft 1 and rotates. Here radial group 14A
, 14B and the disk 3 is called a radial bearing 16, and the bearing part made up of the thrust receiver 4 and the tip end surface 1A is called a thrust bearing 17.

However, this type of hydrodynamic bearing device needs to withstand long-term vibrations during transportation and falling shocks that occur during use. It vibrates in the vertical direction shown in
At this time, the lubricant of the thrust bearing 17 is scattered around, resulting in a shortage of lubricant.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a highly reliable hydrodynamic bearing device that is resistant to vibrations and drops.

Structure of the Invention The hydrodynamic bearing device of the present invention abuts the shaft, the sleeve, and the shaft end surface, the thrust bearing fixed to the sleeve has a member, and the shaft end surface or the thrust bearing has a spiral group on either one of the members. , a lubricant is held at 51 mm, a space is provided near the shaft end face of the sleeve, a C-shaped ring is fixed to the shaft within this space, and this C-shaped ring and the thrust receiver are inserted into the space between the members. In addition, a ring is fixed to a sleeve, and a gap is provided between the inner circumference of the sleeve and the outer circumference of the shaft to hold lubricant, making it a hydrodynamic bearing device that is resistant to vibrations and drop impacts.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. In the figure, 18 is a fixed shaft, 18A is a tip end surface, and 19
is the lower cylinder, 2o is the disk, 2OA is the sleeve part, 20B is the cavity, 21 is the thrust receiver, 22 is the upper cylinder, 23 is the magnetic head, 24 is the rotary transformer on the rotating side, 25 is the rotary transformer on the fixed side, 26 is C
29 is an armature magnet, 30 is a fixed side coil unit, and 29.30 constitutes a direct drive motor 31. Also 20, 21.22゜23.24
．． 29 constitutes a rotation side unit 28. 32A, 3
2B is a radial group, 33 is a spiral group,
A thrust bearing 35 is composed of 18A, 21 and 33, and 18
, 20, 32A, and 32B constitute a radial bearing 34. Further, the thrust bearing 36 and the radial bearing 34 are each independently filled with lubricants 36 and 37 such as oil or grease. The CIJ ring 26 prevents the rotating unit 28 from coming off.

Next, the ring 27, which is the main point of the present invention, will be described. In the present invention, a ring 27 that contacts the thrust receiver 21 and rotates together with the disk 20 is provided between the disk 2o and the fixed shaft 18, so that even if vibration or the like is applied to the hydrodynamic bearing device, the lubricant 36 will not be scattered. <The lubricant 36 is always held at least in the gap between the ring 27 and the shaft 18. In addition, the spiral group 33 has the effect of collecting the lubricant in the center, and by providing the spiral groove 38 on either the outer circumference near the upper part of the fixed shaft 18 or the inner circumference of the ring 27, the scattered lubricant can be more reliably removed. It is collected in the thrust bearing 35. Reference numeral 20c is a ventilation hole, which prevents the lubricant 37 from being pushed out by volumetrically expanded air when the atmospheric pressure changes.

The ring 27 is made of elastic synthetic resin such as PES (polyether sulfone) or PBT (polybutylene terephthalate), which has excellent spring properties, oil resistance, and creep resistance.

Although the embodiment has been described in the case where the shaft tip surfaces IA and 18A are planar bearings, the same applies even if they are spherical bearings or trapezoidal bearings.

As described above, by providing a ring coaxially with the shaft and creating a gap between the inner periphery of the ring and the outer periphery of the shaft to retain lubricant, we have created a fluid bearing device that is safe against vibrations and drop impacts. obtained,
Its practical effects are significant.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional hydrodynamic bearing device, Fig. 2 is a plan view of a conventional spiral group, Fig. 3 is a plan view of the same C-ring, and Fig. 4 is an embodiment of the present invention. cross section,
FIG. 6 is an enlarged view of the main part. 18...axis, 18A...river/tip surface, 20 peaks/
・Disc, 20A...Sleeve, 20B...
・Vacancy, 21... Thrust receiver is a member, 26...
・C-shaped ring, 27...Ring, 33...
...Spiral group 36.37...Lubricant. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A shaft, a sleeve, and a thrust bearing that is in contact with the end face of the shaft and fixed to the end face of the sleeve has a member, and the shaft end face or the thrust bearing has a spiral group on either one of the contact surfaces of the member. The thrust receiver retains a lubricant between the member and the shaft end surface, a space is provided near the shaft end surface of the sleeve, a C-shaped ring is fixed to the shaft within the space, and the C-shaped ring is fixed to the shaft within the space. The C-shaped ring in the cavity and the thrust bearing are fixed to a sleeve, and a gap for retaining lubricant is provided between the inner periphery of the ring and the outer periphery of the shaft. . (2) The hydrodynamic bearing device according to claim 1, further comprising a conveying groove configured to collect lubricant scattered in the gap at the center of rotation.