Method for manufacturing a top foil and a spring foil for a gas thrust bearing, a set of such top spring foils and a gas thrust bearing including such foil set

Abstract

The present invention relates to a method for manufacturing a top foil (10) and a spring foil (20) for a gas foil thrust bearing (1). Each such foil (10; 20) comprising an outer support ring (11; 21), multiple arc-shaped foil segments (12; 22) and support arms (13; 23) extending in radial direction between the support ring (11; 21) and the foil segments (12; 22). Such top foil (10) and spring foil (20) are each cut and formed from metal foil (50) in a stamping process using at least one pair (100) of a punch (60) and a die (80). According to the invention, such at least one punch-and-die pair (100) is correspondingly applied in, i.e. is shared between manufacturing both the top foil (10) and the spring foil (20) of the thrust bearing (1).

Description

[0001] METHOD FOR MANUFACTURING A TOP FOIL AND A SPRING FOIL FOR A GAS THRUST BEARING, A SET OF SUCH TOP SPRING FOILS AND A GAS THRUST BEARING INCLUDING SUCH FOIL SET

[0002] The present invention relates to a gas thrust bearing that is a layered system comprising, at least, a (smooth) top foil and a (corrugated) spring or bump foil. The present invention also relates to a method for manufacturing a set of the top foil and the spring foil for such gas thrust bearing.

[0003] Thrust bearings are used in the art to confine a rotating body such as a motor shaft in its axial direction. Typically such rotating body is further confined in radial direction by a sleeve bearing that -at least in combination with the present gas foil thrust bearing- is typically also a gas foil-type bearing.

[0004] In the gas foil-type bearing a thin film of pressurized gas is build-up and maintained between the top foil of the bearing and the rotating body due to the rotation thereof, i.e. dynamically, to provide a low friction load-bearing interface there between. During normal operation, a top side of the top foil -that is compliant in axial direction for this reason- and the rotating body do not touch, thus minimizing friction and wear and avoiding particulate contamination and lubricant handling associated with sliding or roller bearings. A bottom side of the top foil opposite the gas film is supported by a top side of the spring foil. The spring foil is resilient in the axial direction, for example by being provided with a number of axially protruding, arch-shaped elastically deformable bumps. In turn, a bottom side of the spring foil rests on a rotationally fixed base plate that can be part of the gas bearing, but that can also be an integral part of a housing of the bearing.

[0005] The top foil and spring foil are typically provided in multiple, generally arc-shaped segments that together form a substantially complete circle, supporting the rotating body. Each such foil segment can be attached, e.g. (spot) welded to the base plate at one (tangential) edge thereof and at a mutual angular interval that corresponds to 360 degrees (i.e. 2TT radians) divided by number of segments. However, in order to a / o facilitate the assembly of the gas bearing, it is also known provide the top foil and / or the spring foil with a radially outer support ring and with support arms extending (in radial inward direction) from such support ring to each respective foil segment. In the thrust bearing, the support rings of the top foil and of the spring foil mutually overlap and together are fixed relative to the said base plate, e.g. by being bolted, riveted, clinched, spotwelded, glued thereto, etc.

[0006] Specifically in case of the top foil, it is further known to provide the said foil segments thereof as an integral part, i.e. as a radially inner bearing ring. This particular design of the top foil with the radially outer support ring, the support arms and the radially inner bearing ring is for example known from the US patent No. 6,702,463. In this known design, the inner bearing ring is provided in ten sections, denoted pads in US-6,702,463. These pads are mutually separated by a pleated step in axial direction, such that each such section is inclined from a leading side (as seen in the direction of rotation of the shaft) towards a trailing side thereof. In particular such incline is directed towards the said rotating body in the direction of rotation thereof during operation. This incline helps to dynamically compress and pressurize the gas layer between the top foil of the gas thrust bearing and the rotating body.

[0007] In the art, the said gas thrust bearing foils are typically produced from metal foil by means of an appropriate metal forming process, such as in particular etching, laser cutting or stamping. Foil etching and laser cutting are favorable solutions for production flexibility, i.e. for producing different foil designs in a relatively small volume each. In these cases, the upfront invest in the production equipment for each distinctive design is comparatively low and / or the production equipment can be easily modified to each specific design at comparatively small cost. Foil stamping may, however, be preferable for higher volume production, as it provides a high process speed at low operating cost that offset the comparatively high capital cost (invest) of the stamping tooling used for stamping the top foil and the spring foil, respectively. In fact, multiple stamping punch-and-die pairs are typically applied in such tooling for progressively shaping each bearing foil, including one or more piercing punch-and-die- pairs for firstly piercing holes in the metal foil and one blanking punch-and-die-pair for finally cutting-loose the respective bearing foil from the surrounding foil material.

[0008] The present invention aims to reduce the cost of manufacturing of the known gas foil thrust bearing. More in particular, the present invention aims to reduce the capital cost of stamping the set of the top foil and the spring foil of such bearing.

[0009] According to the present invention, at least one punch-and-die pair is applied correspondingly in the manufacturing of both the top foil and the spring foil of the foil gas thrust bearing. By thus sharing at least the design, but preferably also the hardware of the stamping tooling between the set of bearing foils, the capital cost of foil stamping is favorably reduced.

[0010] In particular, according to the present invention, a punch-and-die pair for cutting, i.e. shaping the (predominantly radially oriented) leading and trailing edges of the foil segments, is shared between the top foil and the spring foil. As a result, the foil segments of the top foil and those of the spring foil thus manufactured have a corresponding tangential extent and contour. In particular, the leading and trailing edges of the foil segments of the top foil and the spring foil will mutually coincide in the gas foil thrust bearing, as seen along the axial direction thereof. At least before the said axially protruding bumps have been pressed into the spring foil, whereby the tangential extent of the foil segments of the bump foil would be reduced relative to such extent of the top foil segments.

[0011] Additionally or alternatively, a punch-and-die pair for cutting the radially inner and / or the radially outer (predominantly tangentially oriented) contour edges of the foil segments of the spring foil is also applied in the manufacturing of the top foil and vice- versa. As a result, the foil segments of the top foil and those of the spring foil thus manufactured will have a corresponding radially inner and / or radially outer contour. In particular, these contours will mutually coincide in the gas foil thrust bearing, as seen along the axial direction thereof.

[0012] Preferably, also a punch-and-die pair for cutting the radially inner (tangentially oriented) contour edges of the support ring between the support arms is shared by the top foil and the spring foil. It being noted that these latter three features of the radially inner and the radially outer contour edges of the foil segments and the radially inner contour edges of the support ring are typically cut simultaneously by a single punch- and-die pair.

[0013] More preferably, all of the above-discussed punch-and-die pairs, including the said blanking punch-and-die-pair for finally cutting-loose the respective bearing foil from the surrounding foil material, are correspondingly applied, i.e. are shared by the top foil and the spring foil. As a result, the support ring, the support arms, and the foil segments of the top foil and those of the spring foil will have the same outer geometry, such that -in the absence of the bumps in the bmp foil- the respective outlines thereof mutually coincide in axial direction.

[0014] The features and advantages of the present invention are further elaborated in the following detailed description of specific, however non-limiting embodiments with reference to the accompanying drawings, whereof:

[0015] Figure 1 is a schematic isometric view of a gas foil thrust bearing of known design;

[0016] Figure 2 is a plan view of a top foil that known bearing design;

[0017] Figure 3 is a plan view of a spring foil that known bearing design;

[0018] Figure 4 illustrates the conceptual setup of the generally known stamping process;

[0019] Figure 5 schematically illustrates the known method for manufacturing the spring foil for the gas thrust bearing; and

[0020] Figure 6 schematically illustrates a novel method for manufacturing a top foil for the gas thrust bearing in accordance with the present invention that can be favorably applied in combination with the spring foil manufacturing method of figure 5 to manufacture a set of the top foil and the spring foil.

[0021] In the drawings, the same or similar reference numerals indicate the same or equivalent elements.

[0022] An exemplar embodiment of the known gas foil thrust bearing 1 is illustrated in figure 1. Specifically in figure 1 , two such thrust bearings 1 are illustrated, one on each axial side of a flange 3 of a shaft 2, such that the shaft 2 is supported in either axial direction. The known thrust bearing 1 includes a top foil 10, having a top side facing the shaft flange 3, and a spring foil 20, located between the top foil 10 and a respective rotationally fixed base plate 40. Shim foils 30 are optionally present depending on the specific bearing design and / or its operating requirements. For example, a shim foil 30 may be included between the spring foil 20 and the top foil 10 for separating these in axial direction to control a compression of axially protruding bumps 26 of the spring foil 20 (see figure 3) by the top foil 10 during operation of the thrust bearing 1 .

[0023] A spacer ring 4 is provided between the two gas thrust bearings 1 , in particular between the respective top foils 10 thereof, concentric with the said shaft flange 3. Bolts 5 are provided to hold together the complete bearing assembly, consisting of the two thrust bearings 1 with the spacer ring 4 there between. During operation, i.e. by the rotation of the shaft flange 3, a gas such as air is drawn into the bearing assembly through recesses 6 in the spacer ring 4, whereby gas pressure is build-up between the shaft flange 3 and the top foils 10 to either axial side thereof. By this gas pressure that increases in relation to a decreasing separation between the shaft flange 3 and a respective top foil 10, the shaft 2 is confined in either axial direction in principle without any physical contact between the shaft flange 3 and the top foils 10.

[0024] The top foil 10 of the known gas foil thrust bearing 1 is illustrated in more detail in figure 2. The top foil comprises a radially outer support ring 11 , a radially inner bearing ring 12 and several support arms 13 extending there between. The top foil support ring 11 is provided with holes 14 for accommodating the said bolts 5. The bearing ring 12 defines a central opening 15 for accommodating the shaft 2.

[0025] In its illustrated embodiment, the bearing ring 12 is provided in six arc-shaped sections 16, separated by creases 17 that each define a step in axial direction between two adjacent such sections 16. The creases 17 are defined such that each respective section 161 of the bearing ring 12 is inclined from its respective leading side 162 to its respective trailing side 163 toward the shaft flange 3 in the direction of rotation thereof during operation.

[0026] The spring foil 20 of the known gas foil thrust bearing 1 is illustrated in more detail in figure 3. The spring foil 20 comprises a radially outer support ring 21 , several arc-shaped bump segments 22 that are located in a circle on the radial inside of the support ring 21 and support arms 23 that respectively extend between the support ring 21 and each respective bump segment 22. The spring foil support ring 21 is provided with holes 24 for accommodating the said bolts 5. Together the bump segments 22 define a central opening 25 for accommodating the shaft 2. A radial clearance is typically provided between such central opening 25 and the shaft 2 for allowing the (bearing) gas to flow through and cool the thrust bearing 1 during operation.

[0027] In its illustrated embodiment, the spring foil 20 is provided with six bump segments 22 in total. Each bump segment 22 is provided in three strips 221 , 222, 223 that are separately attached to a respective support arm 23 and that extend from such support arm 23 in the said direction of rotation of the shaft flange 3. Each bump segment strip 221 ; 222; 223 is provided with 2 or 3 sequential arch-shaped bumps 26; 261 , 262, 263 that project out of a main plane of the spring foil 20 towards the top foil 10 and that thereby resiliently support a respective one of the top foil sections 16 during operation.

[0028] In particular for a relatively large production volume, the top foil 10 and the spring foil 20 are preferably manufactured by means of stamping, i.e. by means of a number of sequential piercing and blanking steps. In figure 4 the known stamping process is schematically illustrated by way of a simplified cross section of a stamping tooling 90 for one such piercing and blanking step. The stamping tooling 90 is shown to include a punch 60, a blank holder 70 and a die 80. The blank holder 70 and the die 80 each define a respective cavity 71 , resp. 81 , wherein the punch 60 is contained.

[0029] On the left side in figure 4 the stamping tooling 90 is shown in an open state, wherein the punch 60 is fully retracted into the blank holder 70 and wherein the blank holder 70 and the die 80 are mutually separated, allowing a strip 50 of metal foil to be inserted there between. In the actual blanking stroke of the stamping tooling 90 that is illustrated on the right side in figure 4, first the blank holder 70 and the die 80 are moved towards one another until the metal foil strip 50 is held in place there between. Then, the actual cutting of a piece 51 from the foil strip 50 takes place by the forced movement of the punch 60 relative to die 80, until the punch 60 has pierced through the foil strip 50 into the cavity 81 of the die 80. In the shown arrangement of the stamping tooling 90, the cut piece 51 is removed from the stamping tooling 90 via the cavity 81 of the die 80. It is, however, also known to apply a counter-punch (not shown) in the die cavity 81 acting on the opposite side of the foil strip 50 relative to the punch 60. In this case, the cut piece 51 is lifted out of the die cavity 81 of the die 80 by the corresponding upward movement of such counter-punch when the stamping tooling 90 is returned to its open state.

[0030] As the blank holder 70 is in principle optional, the essential parts of the stamping tooling 90 are the punch 60 and the die 80, i.e. a punch-and-die pair 100. In practice, multiple such punch-and-die pairs 100 are typically applied in the stamping tooling 90 for progressively shaping each bearing foil. For example, one or more punching punch-and-die-pairs 100 can be included for firstly piercing holes in the foil strip 50 and one blanking punch-and-die-pair for finally cutting-loose the respective bearing foil from the foil strip 50. In this latter respect it is noted that in case of the said punching or piercing process step, the cut piece 51 is removed as scrap, whereas in case of the blanking process step the cut piece 51 is the actual product. Moreover, the punch 60 of a respective punch-and-die pair 100 can include multiple cutters, each received in a respective one of a corresponding number of die cavities 81. Hereby, multiple holes can be cut simultaneously, such as the twelve slits 52 and two holes 53 mentioned hereinafter.

[0031] In figure 5 such progressive stamping process is illustrated in relation to the spring foil 20. The overall stamping tooling 90 for manufacturing the spring foil 20 is shown to be provided with four stamping stations I, II, III, IV that each include a respective one of four punch-and-die-pairs 100 in total.

[0032] In the first stamping station I that is a piercing process step, six pairs of two, essentially tangentially oriented slits 52 are cut in the foil strip 50. These two slits 52 separate the three bump segment strips 221 , 222, 223 of a respective one of the six bump segments 22 in the final product 20 in radial direction. In this first stamping station I also two alignment holes 53 are cut, one on either side of the foil strip 50, for receiving alignment pins 91 of the stamping tooling 90 to accurately align the foil strip 50 relative to the stamping tooling 90.

[0033] In the second stamping station II that is also a piercing process step, six essentially radially oriented slits 54 are cut in the foil strip 50. These latter slits 54 each represent a (leading) edge of a respective one of the six support arms 23 in the final product 20. In this second stamping station II also four further holes 55 are cut that represent the said bolt holes 24 of the spring foil 20.

[0034] In the third stamping station III that is again a piercing process step, a central hole 56 is cut in the foil strip 50, as well as six, tangentially elongated, further holes 57, located radially outward of the said two slits 52 that were cut in the first stamping station I. This central hole 56 represents the said central opening 25 of the spring foil 20, whereas these further holes 57 define the radially outer contour of the bump segments 22, the radially inner contour of the support ring 21 , as well as another (i.e. trailing) edge of the support arms 23 and of the spring foil 20.

[0035] In the fourth stamping station IV that is a blanking process step, the complete radially outer contour 58 of the spring foil 20 is cut, whereby it is cut loose from the foil strip 50 and removed from the stamping tooling 90 as schematically indicated by the arrow in figure 5.

[0036] It is noted that the above discussed implementation of the stamping process and tooling 90 is illustrative only. Other implementations of such process and tooling, in particular in terms of the specific number and / or the specific setup of the stamping stations applied therein, are possible. In fact, even a pressing station for forming the bumps 26 of the spring foil 20 can conceivably be integrated therein, in particular directly preceding the said fourth stamping station IV of blanking the outer contour of the spring foil 20.

[0037] The capital cost of such stamping tooling 90 for manufacturing the spring foil 20 is high, because of the multiple punch-and-die pairs 100 that are required. All the more so, in combination with a stamping tooling dedicated to the manufacturing of the top foil 10. In fact, such tooling cost may in practice be prohibitively high in relation to a limited or uncertain production volume, as will often be the case for applications of the gas foil thrust bearing 1 . However, according to the present invention, such capital cost can be favorably lowered for the economic production of small volumes, by sharing the stamping tooling 90 between the spring foil 20 and the top foil 10 of the gas foil thrust bearing 1 , preferably both such bearings on either side of the shaft flange 3.

[0038] In particular according to the invention and as illustrated in figure 6, the top foil 10 is favorably manufactured using mostly identical stamping tooling 90 as used for the spring foil 20, but with the sole exception of the said first stamping station I. In particular, in case of the top foil 10, the said six pairs of two, essentially tangentially oriented slits 52 are not cut. Otherwise the same stamping tooling 90 and punch-and- die pairs 100 therein are used, such that the respective outer geometry of the top foil 10 and the spring foil 20 will also be the same, at least essentially. In this latter respect it is noted that by the provision of the arch-shaped bumps 26 in the arc-shaped foil segments 22 of the spring foil 20, the tangential extend of these foil segments 22 will be somewhat less than that of corresponding the arc-shaped foil segments 12 of the top foil 10. Nevertheless, as seen in axial direction, the radially outer and the radially inner contour of the respective foil segments 12; 22 of the top foil 10 and of the spring foil 20 coincide in the thrust bearing 1 , as do the said (leading and trailing) edges of their respective support arms 13; 23 and the radially outer and the radially inner contour of their respective support rings 11 ; 21 including the said bolt holes 14; 24 therein.

[0039] Further, according to the invention, the said first stamping station I can still be present in the stamping tooling 90 for manufacturing the top foil 10, however, with the cutters for cutting the said slits 52 not being applied therein. In this case, the two alignment holes 53 on either side of the foil strip 50 are still cut in the first blanking station I. This has the advantage that not only the design of the stamping tooling 90 can be largely shared between a set of the top foil 10 and of the spring foil 20 of the gas foil thrust bearing 1 , but favorably also the (physical) stamping tooling 90 itself. Multiple such foil sets 10, 20 can thus be manufactured with the same stamping tooling 90 in a gas foil thrust bearing 1 production run, while (manually) removing these latter punches from the stamping tooling 90 for producing the top foils 10, respectively installing these in the stamping tooling 90 for producing the spring foils 20.

[0040] Yet further, also the base plates 40 can potentially be manufactured with the same stamping tooling 90 as the said foils 10, 20 by applying (only) the cutters for the said further holes 55, for the said central hole 56 and for the complete radially outer contour 58 (and removing all other punches).

[0041] It is noted that the bump segments 22 of the spring foil 20 are mostly loaded in axial direction by being compressed by the arc-shaped foil segments 12 of the top foil 10 under influence of the gas pressure that is build-up between the top foil 10 and the shaft flange 3 during operation. Hence, the support arms 23 of the known spring foil 20 are aligned with the radial direction, as illustrated in figure 3. Thus, when -in accordance with the present invention- the top foil 10 is manufactured with the same stamping tooling 90 as the spring foil 20, also the support arms 13 of the top foil 10 will be aligned with in the radial direction.

[0042] In case of the top foil 20, however, the arc-shaped foil segments 12 thereof are loaded opt a considerable extent also in tangential direction. Namely, not a drag force is exerted by the gas inside the bearing during normal operation, but also a friction force occurs in that direction when there is physical contact with the shaft flange 3 at starting or stopping of the shaft rotation. To accommodate these tangential forces with minimal (bending) stress, i.e. to optimally transfer it via the support arms 13 to the support ring 11 , the support arms 13 of the top foil 10 (and thus also the support arms 23 of the spring foil 20) are oriented not only in radial direction, but to a substantial extent also in tangential direction. In figures 5 and 6 this design aspect is included in the trailing edge of the support arms 13; 23 that is oriented at an angle of approximately 45 degrees relative to the radial and tangential directions. However, preferably also the leading edge of the support arms 13; 23 is oriented at such angle (not illustrated), at least where it extends between the radially inner contour of the support ring 13; 23 and the radially outer contour of the foil segments 12; 22. The remainder of such leading edge between the radially outer and the radially inner contour of the foil segments 12; 22 is preferably aligned with the radial direction.

[0043] The present invention, in addition to the entirety of the preceding description and all details of the accompanying figures, also concerns and includes all the features of the appended set of claims. Bracketed references in the claims do not limit the scope thereof but are merely provided as non-binding examples of the respective features. The claimed features can be applied separately in a given product or a given process, as the case may be, but it is also possible to apply any combination of two or more of such features therein. The invention(s) represented in the present disclosure is (are) not limited to the embodiments and / or the examples that are explicitly mentioned herein, but also encompasses amendments, modifications, and practical applications thereof, in particular those that lie within reach of the person skilled in the relevant art.

Claims

CLAIMS1. A method for manufacturing a top foil (10) and a spring foil (20) for a gas foil thrust bearing (1), in particular for stamping such bearing foils (10; 20), wherein the top foil (10) and the spring foil (20) are each cut from metal foil (50) using at least one pair (100) of a punch (60) and a die (80), characterized in that the said one punch-and-die pair (100) is correspondingly applied in manufacturing, i.e. in stamping both the top foil (10) and the spring foil (20) of the thrust bearing (1).

2. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 1 , characterized in that the top foil (10) and the spring foil (20) are each cut from metal foil (50) in two or more process steps, while using distinct punch-and-die pairs (100) in each such process step, characterized in that at least two of the said distinct punch-and-die pairs (100) are correspondingly applied in manufacturing both the top foil (10) and the spring foil (20) of the thrust bearing (1).

3. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 1 , characterized in that the top foil (10) and the spring foil (20) are each cut from metal foil (50) in three or more process steps, while using distinct punch-and-die pairs (100) in each such process step, characterized in that with the exception of one such punch-and-die pair (100), the said punch-and-die pairs (100) are correspondingly applied in manufacturing both the top foil (10) and the spring foil (20) of the thrust bearing (1).

4. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 1 , 2 or 3, characterized in that the top foil (10) and the spring foil (20) are each provided with an outer support ring (11 ; 21), with an inner ring of arc-shaped foil segments (12; 22) and with support arms (13; 23) that each extend between the support ring (11 ; 21) and a respective foil segment (12 ;22), and in that the said correspondingly applied punch-and-die pair (100), respectively one of the said correspondingly applied punch-and-die pairs (100) is destined for cutting a tangentially leading trailing edge of the support arms (13; 32) of both the top foil (10) and the bump foil (20).

5. The method for manufacturing the top foil (10) and the spring foil (20) of the gasfoil thrust bearing (1) according to claim 1 , 2 or 3, characterized in that the top foil (10) and the spring foil (20) are each provided with an outer support ring (11 ; 21), with an inner ring of arc-shaped foil segments (12; 22) and with support arms (13; 23) that each extend between the support ring (11 ; 21) and a respective foil segment (12 ;22), and in that the said correspondingly applied punch-and-die pair (100), respectively one of the said correspondingly applied punch-and-die pairs (100) is destined for cutting a tangentially leading or trailing edge of the foil segments (12; 22) of both the top foil (10) and the bump foil (20), preferably is destined for cutting both these tangential edges.

6. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 1 , 2 or 3, characterized in that the top foil (10) and the spring foil (20) are each provided with an outer support ring (11 ; 21), with an inner ring of arc-shaped foil segments (12; 22) and with support arms (13; 23) that each extend between the support ring (11 ; 21) and a respective foil segment (12 ;22), and in that the said correspondingly applied punch-and-die pair (100), respectively one of the said correspondingly applied punch-and-die pairs (100) is destined for cutting a radially inner or outer edge of the foil segments (12; 22) of both the top foil (10) and the bump foil (20), preferably is destined for cutting both these radial edges.

7. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 1 , 2 or 3, characterized in that the top foil (10) and the spring foil (20) are each provided with an outer support ring (11 ; 21), with an inner ring of arc-shaped foil segments (12; 22) and with support arms (13; 23) that each extend between the support ring (11 ; 21) and a respective foil segment (12 ;22), and in that the said correspondingly applied punch-and-die pair (100), respectively one of the said correspondingly applied punch-and-die pairs (100) is destined for cutting the radially inner edges of the support ring (11 ; 21) between the support arms (13; 23) of both the top foil (10) and the bump foil (20).

8. The method for manufacturing the top foil (10) and the spring foil (20) of the gas foil thrust bearing (1) according to claim 4, 5, 6 and / or 7, characterized in that a further punch-and-die pair (100) is applied therein that is destined for cutting the radially outer edge of the support ring (11 ; 21), i.e. for cutting-loose the respective bearing foil from the surrounding foil material, of both the top foil (10) and the bump foil (20).

9. A set of a top foil (10) and a spring foil (20) for a gas foil thrust bearing (1)manufactured with the method of any one of the claims 1-810. A set of a top foil (10) and a spring foil (20) for a gas foil thrust bearing (1), in particular the set according to claim 9, which top foil (10) and which spring foil (20), each comprise an outer support ring (11 ; 21), multiple arc-shaped foil segments (12;22) and support arms (13; 23) extending in radial direction between the support ring (11 ; 21) and the foil segments (12; 22), characterized in that the support arms (13; 23) and / or the foil segments (12; 22) and / or the support ring of both the top foil (10) and the bump foil (20) have the same outer geometry, as seen in axial direction.

11. A gas foil thrust bearing (1) including the top foil (10) and the spring foil (20) manufactured with the method of any one of the claims 1-8.

12. A gas foil thrust bearing (1) including the set of the top foil (10) and the spring foil (20) according to claim 9 or 10.

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