JPS60263720A - Fluid bearing cylinder device - Google Patents

Abstract

PURPOSE:To enable easy removal of a foreign matter in a sleeve, by a method wherein an intermediate part, extending between herringbone type groups formed in 2 spots of axially upper and lower outer peripheral surfaces, of a stationary shaft is formed in a small size and a stepped-structure. CONSTITUTION:Herringbone type groups 5a are formed in a maximum size in 2 spots on axially upper and lower outer peripheral surfaces of a stationary shaft 5, and an intermediate part 5b extending between the 2 herringbone type groups 5a is formed in size smaller than that of the herringbone type group 5a, and a tapered part 7 is formed at a boundary between the herringbone type group 5a and the intermediate part 5b. As a result, an inner surface 6a of the bearing of a sleeve 6 is formed in a straight manner to improve its constitution, and this facilitates machining and washing and removal of a foreign matter.

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 bidet A'y-precorder.

Structure of a conventional example and its problems FIG. 1 shows a sectional view of a conventional hydrodynamic bearing cylinder device, in which 1 is a fixed cylinder that guides a magnetic tape. 2
is a fixed shaft having a herringbone type group 2a on the outer circumferential surface 21Et under which the axis is improved, and is press-fitted concentrically into the center of the fixed cylinder 1. Reference numeral 3 denotes a sleeve fitted around the fixed shaft 2 so as to be rotatable concentrically with the fixed shaft 2, and the sleeve 3 corresponds to the two herringbone groups 2a.
The intermediate portion 3b between the two bearing portions 3a is formed to have a larger diameter than the inner diameter of the bearing portion 3a. 3C is a ventilation hole connecting the outside and the inside of the intermediate portion 3b. Reference numeral 4 denotes a lubricant that is present in minute gaps such as in each herringbone type group 2a of the fixed shaft 2 and in the bearing inner surface 3a of the sleeve 3.

The operation of the hydrodynamic bearing cylinder device constructed as described above will be described below. As the rotating part including the sleeve 13 of this hydrodynamic bearing cylinder device rotates, the two bearing parts 3 a, r4 of the fixed shaft 2, the herringbone type group 2a, etc. of the fixed shaft 2, the lubricant 4 of the sleeve; Due to the pumping action of the full bearing
, the claim-centeredness is maintained, and i
j The intermediate part of the sleeve 3: ) [) and the fixed shaft 2 are J, and the IC space is a space that cannot be filled with lubricant 4, and if this space is filled with 1. r,, the lubricant material 4 is filled and the friction torque of the bearing 1g increases.J-, the air bubbles in the TA lubricant cause the herringbone type group 2a and the bearing part 3a.
This prevents lubricants from getting into the tiny gaps of the engine and preventing normal rotation.

However, with the above-mentioned configuration, it is not easy to machine the stepped inner surfaces of the bearing part 3a and the intermediate part 3b of the sleeve 3, and chips and dust remaining on the bearing part 38 and the intermediate part 3b are difficult to apply. Mastering the cleaning and removal of foreign substances such as number 31, difficult koji.

Here, if this foreign matter gets mixed into the minute gap between the herringbone type group 2a and the bearing part 3a, the herringbone type group 2t, which has been finished with high precision, and the bearing part 3a.
I! Rubbing, abrasion, IE? tr <'K R11 rotation l1f1. However, since the boundary between the bearing part 3a and the intermediate part 3b is stepped, there is no space for hanging the lubricant 4 with sufficient margin. 10 degrees to the right.

[1] An object of the present invention is to provide a hydrodynamic bearing cylinder that has a structure that facilitates the inner diameter machining of the sleeve and allows foreign matter in the sleeve to be easily removed, thereby making it possible to maintain a constant rotation of M1. The goal is to provide equipment.

Structure of the Invention In order to achieve the objective, the present invention provides herringbone type groups at two locations on the upper and lower outer circumferential surfaces in the axial direction, and
A fixed shaft having a stepped structure with a diameter smaller than the outer diameter of the herringbone type group at the intermediate part between the two herringbone type groups, and a fixed shaft rotatably fitted concentrically on the fixed shaft; The sleeve has a straight inner surface. With this, Yoshi 3 [,
The inner surface of the sleeve can be easily modified, and foreign substances that interfere with normal rotation can be easily removed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a sectional view of a hydrodynamic bearing cylinder device according to an embodiment of the present invention.

1 is a fixed cylinder, 4 is a lubricant, and 1 or more have the same structure as shown in FIG. Reference numeral 5 denotes a fixed shaft, and herringbone type groups ha are formed at two locations on the upper and lower outer circumferential surfaces in the axial direction as the maximum diameter. The intermediate portion 5b between these two herringbone groups 58 has a smaller diameter than the herringbone group 5a, and an i-bar shaped portion 7 is provided at the boundary between the herringbone group 5a and the intermediate portion 5b. is formed and -C is formed.

This fixed shaft 5 is arranged concentrically at the center of the fixed cylinder 1.
There are 11 people fixed -C. A sleeve 6 has a straight bearing inner surface 6a, and is fitted around the fixed shaft 1 so as to be rotatable concentrically. 6b is a ventilation hole connecting the outside and the inside of the bearing.

J of I-1 is composed of sea urchins! ,: The operation of the hydrodynamic bearing cylinder device will be explained below. When the rotating part including the sleeve 6 of this hydrodynamic bearing cylinder device rotates, the pumping action of the radial bearing formed by the two herringbone type groups 5a of the fixed shaft 5, the bearing inner surface 6a of the sleeve 6, and the lubricant 4, etc. Maintains billing integrity! This maintains normal rotation.

Also, the intermediate portion 5b of the fixed shaft 5 and the bearing inner surface 6a of the sleeve 6
The space formed by this is a space that cannot be filled with the lubricant 4, and if this space is pulled, the lubricant 4 will fill up and the bearing friction torque will increase, as well as air bubbles in the lubricant 4. This is to prevent this from getting into the minute gap between the herringbone group 5a and the inner surface of the bearing 6a and interfering with normal rotation.

Here, since the intermediate portion 5b of the fixed shaft 5 between the two bearing portions is formed to have a small diameter, the inner surface 6a of the bearing of the sleeve 6 may have a straight configuration, which facilitates machining and facilitates cleaning of foreign matter. Easy to remove and dark) 3. Also, a tapered portion 7 is formed at the boundary between the herringbone glue 75a and the intermediate portion 5b of the fixed shaft 5! :Me, the extra lubricant 4 collects in the wedge-shaped space created by the inner surface 6a of the bearing of the sleeve 6 in this tapered part 7 due to the effect of surface tension, and the lubricant 4 is inserted into the skewer with enough room. In other words, the effect of a lubricant reservoir can be obtained.

As described above, according to this embodiment, it is possible to easily process the bearing inner surface 6a of the sleeve 6, and also to easily wash and remove foreign substances. Further, the lubricant 4 can ensure sufficient suspension. Note that foreign matter attached to the fixed shaft 5 can be easily removed since it is located on the outer periphery.

Explanation beyond the effect of the invention 1p +As is clear, when it comes to the present invention, 1
, a space between the lower two bearing parts is formed by 1 and 1 at the middle part 6 of the fixed shaft: Therefore, the inner surface of the bearing of the sleeve is C well without straight, and the addition 1 is the same as B2. 4
1. It is possible to obtain the effect that it is easy to clean and remove T objects.

This provides the effect that normal rotation of the hydrodynamic bearing cylinder device is maintained.

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional hydrodynamic bearing cylinder device;
Figure (shows a fluid bearing cylinder 8 in an embodiment of the present invention)
It is a sectional view of A position. 5... Fixed shaft, 5a... Herringbone type group, 5b... Intermediate part, 6... Sleeve, 6a... Bearing inner surface, 7... J-bar shape part agent Yoshi Moriki Hiroshi

Claims (1)

[Scope of Claims] 1. Herringbone type groups are provided at two locations on the outer circumferential surface in the axial direction, and an intermediate portion between these two herringbone type groups is provided outside the herringbone type group. A cylinder device is a fluid bearing characterized by having a fixed shaft having a stepped structure with a diameter smaller than the diameter of the cylinder, and a sleeve rotatably fitted around the fixed shaft concentrically and having a straight inner surface. 2. The fixed shaft is formed with a herringbone fiQ group as the maximum diameter, and this herringbone 1! 2. The hydrodynamic bearing cylinder device according to claim 1, wherein a tapered portion is formed at the boundary between the group and the intermediate portion.