CN112997015A

CN112997015A - Foil bearing

Info

Publication number: CN112997015A
Application number: CN201980074225.2A
Authority: CN
Inventors: 沃尔夫冈·布朗恩; 克里斯托夫·诺伊费尔德; 塞巴斯蒂安·魏斯
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-11-13
Filing date: 2019-10-21
Publication date: 2021-06-18
Also published as: EP3880979A1; KR20210089661A; DE102018128299A1; WO2020098866A1

Abstract

The invention relates to a foil bearing (1) for mounting a shaft, comprising a sleeve-shaped bearing housing (2), at least one elastic corrugated foil (3) arranged on the inner circumference of the bearing housing (2), and at least one cover foil (4) which covers the corrugated foil (3) and forms a bearing surface, wherein an insertion groove (5, 6) oriented from the inside to the outside is provided on the inside of the bearing housing (2) for accommodating at least two end edges (7, 8) which delimit the cover foil (4) in the circumferential direction and are arranged in the insertion groove (5, 6) in a freely movable manner in the switchable direction, and wherein at least the cover foil (4) is fixed by one or more axial fastening means in order to prevent lateral displacement from the insertion groove (5, 6). According to the invention, a circumferential groove (9) is provided on at least one axial end region of the inside of the bearing housing (2), into which a securing ring (10) of an axial fastening means, which is designed to cover at least the foils (4), can be inserted.

Description

Foil bearing

Technical Field

The invention relates to a foil bearing according to the features of the preamble of claim 1, which can be used particularly advantageously for mounting low-load shafts which are operated at high rotational speeds, for example in compressors, gas turbines, turbochargers and the like.

Background

Foil bearings are hydrodynamic or aerodynamic bearings in which, in the unloaded state, the bearing surface supporting the rotatably mounted shaft is formed by a thin and wear-resistant cover foil which is itself supported by an elastic corrugated foil arranged between the cover foil and the bearing housing. In the operation of the bearing, a hydrodynamic or aerodynamic film is formed between the shaft and the cover foil, which film carries the shaft. Only during start-up and stop-down, a direct moving contact between the shaft and the cover foil occurs.

Such a foil bearing for supporting a shaft is known, for example, from DE 102015224866 a 1. The foil bearing is formed by a sleeve-shaped bearing housing which in a first embodiment has a single elastic corrugated foil arranged at the inner circumference of the bearing housing and a single cover foil covering the corrugated foil, which cover foil forms a bearing surface for the shaft. In a second embodiment, the foil bearing has three elastic corrugated foils arranged one behind the other in the circumferential direction and at the inner circumference of the bearing housing and three cover foils covering the corrugated foils, which form three bearing surfaces for the shaft. Irrespective of the number of the foil packs, one or three pairs of insertion grooves oriented from the inside to the outside are provided on the inside of the bearing housing, in which insertion grooves the end edges of the cover foils and the corrugated foils are accommodated and can be freely moved in the direction of the insertion grooves. Since the plug-in groove is open on both axial sides, in order to prevent the foil stack from moving laterally from the plug-in groove into each end edge of the corrugated foil and the cover foil, a slot-shaped recess is additionally formed, which recess interacts with a bolt inserted into a bore through the bearing housing and the plug-in groove, respectively, which bolt serves as an axial fastening means for the foil stack.

However, a disadvantage of such foil bearings is the high production outlay and the associated relatively high production costs for cutting the recesses in the end edges of the corrugated foil and the cover foil and for introducing the pin holes for axially fastening the foil stack.

Disclosure of Invention

Based on said drawbacks of the known prior art, the invention is therefore based on the object of: a foil bearing is provided which, while maintaining the tangential mobility of the cover foil in the plug-in groove, has an inexpensive-to-manufacture axial fastening which counteracts a lateral displacement of the foil stack from the plug-in groove.

According to the invention, this object is achieved in a foil bearing according to the preamble of claim 1 in that a circumferential groove is provided at least one axial end region of the inner side of the bearing housing, into which groove a securing ring of an axial fastening means configured to cover at least the foil can be inserted.

Preferred embodiments and advantageous developments of the foil bearing formed according to the invention are described in the dependent claims. In accordance with claim 2, it is proposed in the foil bearing designed according to the invention that the plug-in groove is designed to be open on both axial sides in the inner side of the bearing housing and that a circumferential groove for a securing ring for axially securing at least the cover foil on both sides is formed in both axial end regions of the inner side of the bearing housing. Alternatively, it is also possible, however, for the plug-in groove in the inner side of the bearing housing to be closed on one axial side and for only the end region of the other open axial side to be provided with a circumferential groove, into which only one securing ring for axially securing at least the cover foil is inserted.

According to claim 3, a further feature of the foil bearing formed according to the invention is that the securing ring has a rectangular profile cross section with a radial height such that the plug groove which is open on both axial sides can be covered over at least one third and up to 100% of its radial extent. The design of the securing ring with such a radial height should ensure that: at least the cover foil is reliably secured against lateral displacement from the plug-in groove despite its tangential movability in the plug-in groove and at the same time precludes contact between the shaft to be supported and the securing ring.

A suitable development of the foil bearing constructed according to the invention, also according to claim 4, is: the circumferential grooves each have an opening in the bearing housing facing the axial side of the bearing housing, into which a tool can be introduced when the securing ring is detached. The opening is preferably designed as a milled-out section which reaches the bottom of the plug-in groove and has a length which is suitable for placing a tool for removal on the end of the securing ring.

Finally, as an advantageous embodiment of the foil bearing designed according to the invention, it is also proposed in claim 5 that the end edge of the at least one corrugated foil is designed flat and is arranged, together with the end edge of the cover foil, tangentially movably in an insertion groove on the inside of the bearing housing and is axially fixed by means of a fixing ring. By fixing the end edge of the at least one corrugated foil together with the end edge of the cover foil in the plug-in groove in the inner side of the bearing housing, it is advantageously not necessary to fix the at least one corrugated foil separately in the bearing housing.

The foil bearing formed according to the invention thus has the following advantages over foil bearings known from the prior art: the foil bearing has an inexpensive axial fastening against lateral displacement of the foil stack from the plug-in groove, while maintaining the tangential mobility of the cover foil in the plug-in groove in the inner side of the bearing housing, by means of a securing ring which can be inserted into a circumferential groove in the bearing housing.

Drawings

A preferred embodiment of a foil bearing constructed in accordance with the present invention is described in detail below with reference to the accompanying drawings. Shown here are:

FIG. 1 shows a side view of a foil bearing constructed in accordance with the present invention, along with a supported shaft;

FIG. 2 shows a perspective view of a foil bearing constructed in accordance with the invention when the foil set is installed;

FIG. 3 shows a perspective view of a foil bearing constructed in accordance with the present invention after the mounting of a retaining ring;

fig. 4 shows a cross-section of a bearing housing of a foil bearing constructed in accordance with the present invention.

Detailed Description

Fig. 1 shows a foil bearing 1 for mounting a shaft, not shown in detail, which is formed from a sleeve-shaped bearing housing 2, three elastic corrugated foils 3 arranged in succession in the circumferential direction on the inner circumference of the bearing housing 2, and three cover foils 4 which each cover the corrugated foils 3 and form a bearing surface. Furthermore, fig. 2 and 3 show that three pairs of plug-in

grooves

5, 6 are provided on the inside of the bearing housing 2, said grooves being oriented from the inside to the outside and serving to receive

flat end edges

7, 8 of the cover foil 4, and said

end edges

7, 8 being arranged in said grooves so as to be freely movable in the axial direction. The end edges, not shown in detail, of the corrugated foils 3 are likewise formed flat here and are arranged together with the

end edges

7, 8 of the cover foils in the plug-in

grooves

5, 6 in the inner side of the bearing housing 2.

It can also be seen in fig. 2 that the plug-in

grooves

5, 6 are formed open on both axial sides in the interior of the bearing housing 2 and that two

circumferential grooves

9, 11, which are clearly visible in fig. 4, are formed in the axial end region of the interior of the bearing housing 2, into which grooves two

securing rings

10, 12, which are formed as axial securing means for the corrugated foils 3 and the cover foils 4, are inserted. As is shown in fig. 3, the

fastening rings

10, 12 have a rectangular profile cross section with a radial height such that the

plug grooves

5, 6 which are open on both axial sides are covered up to 100% of their radial extent. The foil set formed from the corrugated foil 3 and the cover foil 4 is thus reliably secured in the bearing housing 2 despite its tangential movability in the plug-in

grooves

5, 6, so as to prevent lateral displacement from the plug-in

grooves

5, 6, and at the same time to exclude contact between the shaft to be supported and the

securing rings

10, 12.

Finally, it can also be seen in fig. 3 that the

circumferential grooves

9, 11 each have an opening 13 in the bearing housing 2 facing the axial side of the bearing housing 2, into which a tool can be introduced when the

securing rings

10, 12 are detached. It is clearly visible that the openings are designed as milled sections which reach the bottom of the

plug grooves

5, 6 and have a length which is suitable for placing a tool for removal on the end of the

securing rings

10, 12.

Description of the reference numerals

1 foil bearing

2 bearing housing

3 corrugated foil

4 cover foil

52 to the wall of the container

62 of the socket

74 end edge

84 end edge

9 groove

10 fixed ring

11 groove

12 fixed ring

13 opening

Claims

1. Foil bearing (1) for mounting a shaft, comprising a sleeve-shaped bearing housing (2), at least one elastic corrugated foil (3) arranged at the inner circumference of the bearing housing (2), and at least one cover foil (4) which covers the corrugated foil (3) and forms a bearing surface, wherein an insertion groove (5, 6) which is oriented from the inside to the outside is provided at the inside of the bearing housing (2) and is intended for accommodating at least two end edges (7, 8) which delimit the cover foil (4) in the circumferential direction and are arranged in the insertion groove (5, 6) so as to be freely movable in the radial direction, wherein at least the cover foil (4) is fixed against lateral displacement from the insertion groove (5, 6) by means of one or more axial fastening means,

it is characterized in that the preparation method is characterized in that,

at least one axial end region of the inside of the bearing housing (2) is provided with a circumferential groove (9) into which at least a securing ring (10) of an axial fastening mechanism, which is designed as a cover foil (4), can be inserted.

2. Foil bearing (1) according to claim 1,

it is characterized in that the preparation method is characterized in that,

the plug-in grooves (5, 6) are open on both axial sides in the inner side of the bearing housing (2), and circumferential grooves (9, 11) for fixing rings (10, 12) for axially fastening at least the cover foil (4) on both sides are formed in both axial end regions of the inner side of the bearing housing (2).

3. Foil bearing (1) according to claim 2,

it is characterized in that the preparation method is characterized in that,

the fastening rings (10, 12) have a rectangular profile cross section with a radial height such that the plug grooves (5, 6) which are open on both axial sides can be covered over at least one third up to 100% of their radial extent.

4. Foil bearing (1) according to claim 3,

it is characterized in that the preparation method is characterized in that,

the circumferential recesses (9, 11) each have an opening (13) in the bearing housing (2) facing the axial side of the bearing housing (2), into which a tool can be inserted when the fastening rings (10, 12) are removed.

5. Foil bearing (1) according to claim 4,

it is characterized in that the preparation method is characterized in that,

the end edge of the at least one corrugated foil (3) is formed flat and is arranged in the plug-in groove (5, 6) in the inner side of the bearing housing (2) in a manner that it can move freely in a tangential direction together with the end edge (7, 8) of the cover foil and is axially fixed by the fixing ring (10, 12).