JPS60231012A - Foil bearing - Google Patents

Abstract

PURPOSE:To eliminate the need of a fixing member and prevent an unforeseen displacement of a foil by inserting the wound-up portion which is formed by winding the one-side part of the foil, into each groove which is formed in a housing or a rotary shaft. CONSTITUTION:Each foil 1 is shaped from one resilient material such as stainless foil or the like. Each of the foils is curved to have a radius curvature of R1 and wound along the periphery of a rotary shaft which is supported contactlessly with the foil bearing when said shaft is held in the mounted state as specified. The foil each has a wound-up portion 2 integrally formed at one side thereof. The radius R2 of the wound-up portion 2 is a little longer than the internal radius of each groove 4 which is formed in the housing 3 of the foil bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a foil bearing, which is a type of dynamic pressure gas bearing.

(b) Conventionally, in conventional foil bearings, as the foil fixing means, a separate key b is fixed to the foil a by spot welding, as shown in FIG. 7, and as shown in FIG.
It is common practice to fit this into a keyway d provided in the housing C and fix it.

However, with such a structure, the key b is attached to the foil.
Not only does this require a process for welding, but if a gap is created between the key b and the key groove d due to dimensional tolerances during machining, there is a problem in that the foil i is likely to become so-called "unsteady."

(c) Purpose The present invention was made with attention to such circumstances,
The purpose of this invention is to eliminate the inconvenience of having to attach a separate fixing member such as a key to the foil, and at the same time to provide a foil bearing with a structure that does not cause unexpected displacement of the foil even due to slight processing tolerances. There is.

(D) Structure In order to achieve the above object, the present invention has one end of the foil wound to form a winding portion at one end of the foil J, and a groove provided on the housing or the rotational shaft side. The foil is characterized in that a winding part is inserted and the winding part is brought into close contact with the groove by its elastic rotation force, so that the foil remains constant.

(E) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

First, FIG. 1 shows an example of a foil used in the present invention. This foil l is molded from a single piece of elastic material such as a thin stainless steel plate, and is curved with an appropriate bending radius R1 along the circumference of the rotating shaft that is supported in a non-contact manner on the foil bearing in a predetermined installed state. At the same time,
A winding portion 2 is formed at one end thereof. That is, the foil l is made by winding the original material a suitable number of times, for example two or three times, from one end, and integrally forming a cylindrical winding part 2 at one end. The foil 2 is made to extend from the outer end. The winding radius R1 of the winding portion 2 is adjusted to be larger than the inner radius of the groove provided on the housing side of the foil bearing.

This foil l is then attached to the inner surface of the housing 3 as shown in FIG.

For this purpose, the inner surface of the housing 3 is provided with axial grooves 4,4, . . The valley groove 4 has a predetermined inner radius and opens narrowly into the inner circumferential surface of the housing 3 in order to fix the winding portion 2 of the foil 1 in a state in which the foil 1 is led out so as not to be able to escape. Then, the winding portion 2 is slid and inserted into each lI4 from the axial direction. At this time, the foil l is further wound around the winding part 2 from the inside to reduce the winding radius R2 to be smaller than the inner radius of the groove 4, and at the same time, this causes the winding part 2 to recover elasticity. Save your power. Then, while maintaining this state, the winding a2 is inserted into the valley groove 4 in a loosely fitted state, and after the five insertions are completed, the state in which the winding part 2 is held in place is released. Then, this winding portion 2 expands due to its own elastic recovery force (spring strength) and is brought into close contact with the inner circumferential surface of the groove 4 with an appropriate pressure.

Incidentally, the work of reducing the winding portion 2 of the foil 1 by the force of inwardly winding it can be easily accomplished by using an auxiliary tool such as the one shown in FIG. 4. That is, while a folded part 6 is provided in advance at the end of the foil located inside the winding part 2, a cylindrical instrument 8 having a slit 7 in the radial direction is used, and the folded part 6 is inserted into the slit 7. To reduce the winding radius R1 of the winding part 2 by inserting it into the inside of the winding part 2 in a folded state, turn this cylindrical tool 8 to stick the foil on its outer circumferential surface and wind it. The part 2 is rolled up inside. After expanding the winding portion 2 within the groove 4 of the housing 3,
This cylindrical instrument 8 may be removed.

In this way, the foil 1 is fixed to the housing 3 by inserting its winding portion 2 into the groove 4 of the housing 3 and bringing it into close contact with the groove 4 by its elastic recovery force. FIG. 3 shows the structure of the foil bearing constructed in this way, in which each foil 1 is fixed to the housing 3 by its winding portion 2, and is also placed in a floating state within the housing 3, and is subjected to rotational force through dynamic pressure. 5 in a non-contact manner.

In such a structure, since the winding part 2 formed at one end of the foil l consists of a fixing part to the groove 4 of the housing 3, there is of course no need to provide a separate fixing member, and the winding Since the turning part 2 is in close contact with the groove 114 by its own elastic recovery force, it can always fit into the groove 4 regardless of the machining tolerance of the spring 4, which may cause "wobble" in the foil 1. can be eliminated.

In addition, since the foil l extends integrally from the fixed winding part 2, this winding part 2, which acts as a spring against the deformation of the foil l, has a good elastic support function for the foil l. This has the effect of doubling the elasticity of each foil 1.

Note that the configuration according to the present invention is not limited to the structural type of the foil bearing, and is applicable to all foils and their fixing parts. FIG. 5 shows such an example, in which the rotating shaft 5 is surrounded by one 7-upper foil l', and the upper foil l' is supported by a plurality of underfoils l''. I'm trying to do that.However,
Even in such a case, winding portions 2' and 2 are provided at one end.
°°, 2'... are formed in the housing 3 in the same way as in the previous embodiment.
It can be fixed to

Also, the side to which the foil is fixed is not limited to the housing side.
As shown in Fig. 6, there are grooves 4゛, 4°'' on the rotating shaft 5 side.
It is also possible to provide φ and fix the foils l°", 1", .

In carrying out the present invention, various methods can be adopted for forming and winding the foil.
There is no particular limitation, and various methods other than the above-mentioned winding method can be applied to the means for applying springback force to the foil winding portion.

(F) Effects Since the present invention has the above-described configuration, it also eliminates the need to attach a fixing member such as a separate key to the foil.

The winding part that forms the fixing part is in close contact with the groove regardless of the processing tolerance, and it is possible to reliably prevent the foil from wobbling, thereby ensuring a stable rotational state. . Further, in the present invention, the winding portion fixed to the foil exhibits an elastic support function, and this also has the effect of improving bearing performance.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention. That is, Fig. 1 is a perspective view of the foil, Fig. 2 is a perspective view showing how the foil is assembled to the housing, Fig. 3 is a sectional view of the bearing in the assembled state of the foil, and Fig. 4 is a reduced view of the winding portion of the foil. FIG. 5 and 6 are bearing cross-sectional views showing other embodiments. 7 and 8 show a conventional example. FIG. 7 is a perspective view of the conventional foil, and FIG. 8 is a partially sectional view of the housing showing its assembled state. l, 1゛, 1 ”, 1°”...Φ foil 2.2゛, 2
″, 2°″... Winding part 311 @ Housing 4.4', 41', 4'''... Structure 5 - One rotating shaft agent Patent attorney Hiroshi Akazawa Figure 1 R1 Figure 3 Figure 2 Figure 4 Figure 5 Figure 7 Figure 6 Figure 8

Claims (1)

[Claims] One end of the foil is wound to form a wound portion at one end of the foil, and the wound portion is inserted into a groove provided on the housing or the rotating shaft, and its elastic recovery force causes the wound portion to fit into the groove. A foil bearing characterized by fixing the foils by bringing them into close contact.