Foil Bearing, Method for Setting a Gap Geometry of a Foil Bearing, and Corresponding Production Method of a Foil Bearing

Abstract

A foil bearing includes a bearing back, a foil arrangement, and a setting mechanism. The bearing back includes a passage opening configured to receive a shaft, such that a gap is formed between the shaft and the bearing back. The foil arrangement defines a first inner circumference and includes a first segment-shaped foil arranged in the gap adjacent to the bearing back, a second segment-shaped foil arranged in the gap adjacent to the first segment-shaped foil, and a third segment-shaped foil arranged in the gap between the shaft and the second segment-shaped foil. The setting mechanism is configured to set the first inner circumference.

Claims

1. A foil bearing, comprising: a bearing back including a passage opening configured to receive a shaft, such that a gap is formed between the shaft and the bearing back; a foil arrangement defining a first inner circumference and including a first segment-shaped foil arranged in the gap adjacent to the bearing back, a second segment-shaped foil arranged in the gap adjacent to the first segment-shaped foil, and a third segment-shaped foil arranged in the gap between the shaft and the second segment-shaped foil; and a setting mechanism configured to set the first inner circumference.

2. The foil bearing as claimed in claim 1, wherein the setting mechanism includes a first screw enabling the foil arrangement to be positioned in an axial direction and/or a radial direction.

3. The foil bearing as claimed in claim 1, wherein the third segment-shaped foil encloses at least 340° between a first edge at a first end of the third segment-shaped foil and a second edge at a second end of the third segment-shaped foil.

4. The foil bearing as claimed in claim 1, wherein the setting mechanism is at least partially arranged in the bearing back.

5. The foil bearing as claimed in claim 1, wherein the setting mechanism includes a first end position and a second end position and is configured to be continually adjusted between the first end position and the second end position.

6. The foil bearing as claimed in claim 5, wherein the third segment-shaped foil touches the shaft when the setting mechanism is in the second end position.

7. The foil bearing as claimed in claim 5, wherein: when the setting mechanism is in the second end position, the setting mechanism forces a second circumference of the foil arrangement; the second circumference is different from the first inner circumference; and the second circumference is reduced by a factor of 0.999 in relation to the first inner circumference when the setting mechanism is in the first end position.

8. The foil bearing as claimed in claim 1, wherein the second segment-shaped foil is configured as a metal fabric.

9. A method for setting a gap geometry of a foil bearing, the foil bearing including a bearing back, a foil arrangement, and a setting mechanism, the method comprising: determining an operating state and/or a rotational speed of a shaft mounted in a passage opening of the bearing back so as to form a gap geometry between the shaft and the bearing back; determining a suitable setting of the gap geometry using the determined operating state and/or prevails, and/or the rotational speed; and positioning the setting mechanism so as to adjust the determined gap geometry, wherein the foil arrangement defines a first inner circumference and includes a first segment-shaped foil arranged in the gap geometry adjacent to the bearing back, a second segment-shaped foil arranged in the gap geometry adjacent to the first segment-shaped foil, and a third segment-shaped foil arranged in the gap geometry between the shaft and the second segment-shaped foil.

10. The foil bearing as claimed in claim 1, wherein the foil bearing is formed by: providing the bearing back; providing the first, second and third foil segment-shaped foils; providing the setting mechanism; arranging the setting mechanism within the bearing back; and arranging the first, second, and third segment-shaped foils within a cavity defined by the bearing back.

11. The foil bearing as claimed in claim 2, wherein the setting mechanism further includes a second screw.

12. The foil bearing as claimed in claim 11, wherein the setting mechanism further includes a third screw.

13. The method as claimed in claim 9, further comprising: setting the first inner circumference with the setting mechanism.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further features and advantages of the present invention are explained below using embodiments with reference to the figures.

[0027] In the figures:

[0028] FIG. 1 shows a schematic cross-sectional view of a foil bearing according to an embodiment of the present invention;

[0029] FIG. 2 shows a schematic cross-sectional partial view of FIG. 1;

[0030] FIG. 3 shows a schematic cross-sectional view of an example of a foil bearing;

[0031] FIG. 4 shows a schematic cross-sectional view of an example of a foil bearing;

EMBODIMENTS OF THE INVENTION

[0032] The same reference signs denote identical or functionally identical elements in the figures.

[0033] FIG. 1 shows a schematic cross-sectional view of a foil bearing 100 according to an embodiment of the present invention.

[0034] The foil bearing 100 is bounded in this case by a bearing hack 101. The setting mechanism 110 is arranged within the bearing back 101 and formed by screws 105a-c which are each arranged in a bore 111a-c. A passage opening 102 in which a shaft 103 is arranged centrally is formed within the bearing back. The shaft 103 is surrounded by a uniform gap S with a constant width in the circumferential direction. The foil arrangement 107 is formed within the gap, between an inner surface O of the bearing back 101 and the shaft 103. The foil arrangement 107 comprises three foils, a first foil 107a, a second foil 107b and a third foil 107c. The first foil 107a is designed here as the bottom foil, the second foil 107b as the bump foil and the third foil 107c as the top foil.

[0035] In this embodiment, the foils 107a-c are designed in the shape of segments of a cylinder. However, it should be noted that the foils 107a-c can also be of another shape without departing from the scope of protection of the invention. The foils 107a-c each have a first edge 109a and a second edge 109b. In the drawing, which is not true to scale, the edges 109a and 109b enclose an angle of 320° or 40°. That is to say that the foils encircle an angle of 320° of a full circle and that foils are not arranged in the remaining region of 40°. In practice, an angle of approx. 345° would generally result.

[0036] FIG. 1 shows the setting mechanism 110 and the screws 105a-c in a first position in which the screws 105a-c end flush with the inner surface of the bearing back. The foils 107a-c therefore lie against the inner surface O of the bearing back 101, and a gap S of maximum width is set by the setting mechanism 110 and/or by the screws 105a-c.

[0037] FIG. 2 shows a schematic cross-sectional view of a cutout of a foil bearing 100 according to FIG. 1.

[0038] In FIG. 2, the setting mechanism 110 is formed by a screw 105a. FIG. 2 shows the screw 105a in a further position which differs from the first position according to FIG. 1. The screw 105a here is screwed deeper into the bore 111a of the bearing back 101, and therefore the screw no longer ends flush with the inner surface of the bearing back 101, but rather protrudes from said inner surface. The foil arrangement 107 is therefore pushed away from the inner surface O of the bearing back 101 by the screw 105a. Accordingly, smaller circumference of the foil arrangement 107 is forced.

[0039] Although the present invention has been described with reference to preferred exemplary embodiments, it is not restricted thereto. In particular, the materials and topologies mentioned are merely by way of example and are not restricted to the explanatory examples.

[0040] The design of the foil bearing is not restricted to the above-described embodiments, but rather can be adapted as desired to the particular application. For example, the number of screws of a setting mechanism can be adapted to the prevailing conditions. Furthermore, the shape of the foil bearing, of the bearing back, of the foil arrangement and of the shaft is not restricted to the cylinder shape illustrated.

[0041] The invention can be used in all foil bearings, the construction of which includes a bump foil and a top foil. In addition, the invention can also be used in what are referred to as mesh foil bearings. In the case of a mesh foil bearing, the bump foil is replaced by a metal fleece.