CZ306630B6 - Segmented radial bearing - Google Patents

Abstract

The segmented radial bearing has the segments (2) fixed against the circumferential and the axial displacement with the adjusting screws (3) passing radially through the body (1) of the bearing and provided with the nuts (4). Withal, between the body (1) and the bearing segments (2) there are arranged the elastic constraint elements (9). The segment (2) is, by means of the axially situated pin (8), placed pivotally on the strap (6), in whose outer peripheral portion, there is sunk the end of the adjusting screw (3) provided with the collar (5).

Description

Segmented radial bearing

Field of technology

The invention relates to an aerodynamic plain bearing, the tilting segments of which are fixed against circumferential and axial displacement by adjusting screws with nuts, wherein resilient delimiting elements are inserted between the bearing body and the segments.

Prior art

Segment bearing is the most commonly used type of aerodynamic bearing. Segment bearings are characterized by good dynamic properties; they are able to ensure the stability of the rotor in almost all conditions. In order to be able to form a sufficiently load-bearing gas film on the sliding surface of the segment, aerodynamic bearings, in contrast to hydrodynamic bearings, have only 3 segments.

Aerodynamic plain bearings are known in which the segments are tilted by rolling on their outer cylindrical surface. Although there is no wear during rolling, the production technology is demanding, because the centers of curvature of the inner and outer cylindrical surfaces of the segment are different. Especially with smaller values of bearing clearance, it is very difficult to observe the required tolerances. To this end, such segments cannot tilt in the transverse direction.

In the case of the plain bearing described in CS 230535, the pivot segments are mounted on pins mounted in recesses of the radial supports mounted in the bearing housing. The construction of this bearing is relatively complex and demanding on production accuracy. The lower segments are mounted on rigid supports, so that in the event of an impact load, eg rapid changes in position, the segments may come into contact with the rotor.

CZ 300719 discloses a sliding radial bearing with tilting segments, which consists of a bearing housing, tilting segments, adjusting pins with nuts, in which one end of the adjusting pins is arranged in the tilting segment and the other end in the bearing housing. Between the segments and the bearing body, elastic delimiting elements are inserted - flat springs, through which the adjusting pins provided with a collar abutting in the direction from the center of the bearing to the elastic delimiting element are threaded. The disadvantage of this solution is that it substantially limits the possibility of tilting the segment, both because the adjusting pin is mounted directly in the segment and because the deformation of the resilient delimiting element causes the segment to come into contact with the delimiting element at two points.

CZ 304852 describes a sliding radial bearing of essentially the same composition as the previous document. Holes for set screws are made in the bearing housing, and axial recesses are made in the segments on the side adjacent to the bearing housing. A rounded insert is arranged in each harvest, the insert having a smaller width in the longitudinal section than the width of the recess. Threaded holes are made in the inserts coaxial with the holes in the bearing housing. Adjusting screws are inserted into the threaded holes in the inserts and into the holes in the bearing housing, by means of which the degree of abutment of the inserts on the flexible delimiting elements in the direction from the center of the bearing is set. Ό In this solution, the segment rolls with its rounding after rounding of the insert, which has a smaller radius than the rounding of the segment. The problem is that when adjusting the position of the segment, and thus the play in the bearing, the insert rotates about the axis of the adjusting screw, which can be reflected in the corresponding rotation of the segment. The result is then the contact of the sliding surface of the segment with the shaft.

The object of the invention is to provide a segmented radial bearing which, in a simple arrangement, eliminates the stated disadvantages of the known solutions.

- 1 CZ 306630 B6

The essence of the invention

This task is fulfilled by a segmented radial bearing, the segments of which are fixed against circumferential and axial displacement by adjusting screws passing radially through the bearing housing and provided with nuts, wherein resilient delimiting elements are arranged between the bearing housing and the segments. The essence of the bearing lies in the fact that each segment is pivotably mounted on a yoke by means of an axially situated pin, in the outer circumferential part of which the end of the adjusting screw provided with a collar is recessed.

In a preferred embodiment of the bearing, the yoke engages in circumferential grooves formed on the sides of the segment, the pin passing through the segment.

To allow the transverse tilting of the segment, the pin in the segment is mounted with radial play.

The collar at the end of the adjusting screw may be flush with or embedded in the outer peripheral surface of the yoke.

In the described bearing arrangement, the segments can tilt freely regardless of the deformation shape of the elastic elements. The nuts can be used to adjust the bearing clearance during assembly, which reduces the demands on production accuracy. The flexible elements limit the transmission of vibrations and their stiffness and preload can be used to tune the dynamic properties of the bearing.

Explanation of drawings

The invention will be further elucidated with the aid of the drawings, which represent two alternative embodiments of a radial segment bearing. Giant. 1, 2 and 5 relate to a bearing in which the collars on the set screws align with the outer circumferential surface of the yokes, Figs. 3, 4 and 6 then bearings with recessed collars. In this case, FIGS. 1 and 3 are sections A-A according to FIGS. 4, FIGS. 2 and 4 are sections B-B according to FIGS. 3 and FIGS. 5 and 6 are details of the mounting of the upper segments according to FIGS. 4.

Examples of embodiments of the invention

As can be seen from Figures 1 to 6, the bearing according to the invention consists of a body 1 in which three segments 2 are accommodated, forming an opening for accommodating a shaft. Three adjusting screws 3, intended primarily to fix the position of the segments 2 in the circumferential and axial directions, pass through the radial holes inside the bearing body 1. The set screws 3 are provided with nuts 4 and have collars 5 at the ends by which they are embedded in the outer circumferential part of the yokes 6. Each yoke 6 encloses the segment 2 and extends into circumferential grooves 7 formed on the outer circumference of each segment 2. pivotally connected to the segment 2 by means of a pin 8 mounted both in the yoke 6 and in the body of the segment 2. As can be seen from Figs. 2 and 4, a radial clearance is left in the bearing of the pin 8 in the body of the segment 2, which allows the segment 2 to tilted not only around the pin 8, but also in the transverse direction.

Between the bearing housing 1 and the segments 2, delimiting elements 9 are inserted, which are leaf springs allowing the clearance between the shaft and the segments 2 to be adjusted and limiting the transmission of vibrations from the shaft to the bearing housing. To adjust the clearance, the nuts 4 of the adjusting screws 3 are used, the tightening of which increases the preload in the elastic elements 9 and increases the clearance of the shaft.

If the film thickness on a segment is reduced below a safe limit, the resilient elements 9 will allow the stirrups 6 with the segments 2 to be moved in the radial direction and thus the film layer to be renewed.

Claims (5)

PATENT CLAIMS A segmented radial bearing, the segments (2) of which are fixed against circumferential and axial displacement by adjusting screws (3) passing radially through the bearing body (Ij and provided with nuts (4), wherein bearings and segments (2) are arranged between the bearing housing (1) and the segments (2). resilient delimiting elements (9), characterized in that the segment (2) is pivotably mounted on the yoke (6) by means of an axially situated pin (8), in the outer peripheral part of which the end of the adjusting screw (3) provided with a collar (5) is recessed. . Bearing according to claim 1, characterized in that the yoke (6) engages in circumferential grooves (7) formed on the outer circumference of the segment (2), the pin (8) being accommodated in the body of the segment (2). Bearing according to Claim 1 or 2, characterized in that the pin (8) is mounted in the segment (2) with a radial play. Bearing according to one of Claims 1 to 3, characterized in that the collar (5) at the end of the adjusting screw (3) aligns with the outer circumferential surface of the yoke (6). Bearing according to one of Claims 1 to 3, characterized in that the collar (5) at the end of the adjusting screw (3) is embedded in the outer circumferential surface of the yoke (6).