Airfoil journal bearings with improved clamping force

Abstract

The present invention relates to an airfoil journal bearing with improved fastening force, and more specifically, to an airfoil journal bearing with improved fastening force that enables bearing assembly without a process such as welding and prevents the detachment of a bump foil provided inside a bush. According to an embodiment of the present invention, an airfoil journal bearing installed on a rotating shaft of a turbomachine or air cycle machine comprises: a bush formed in the shape of a ring made of aluminum, having a predetermined receiving space in which the rotating shaft is inserted into the inner diameter, a seating portion formed on the outer surface, and a seating groove that opens the receiving space toward the seating portion; and a bump foil having a bent portion that is rolled up and embedded in the receiving space of the bush, wherein one end is inserted into the seating portion, and a first coupling portion is formed that extends parallel to the bent portion so as to be fixed to a seating bottom portion formed in the seating portion. The present invention provides an airfoil journal bearing with improved fastening force, comprising: a top foil formed with a width and length corresponding to the bump foil and seated on the inner surface of the bump foil, and having a second coupling part corresponding to the first coupling part; wherein the bush, bump foil, and top foil are detachably provided by fastening a coupling member to a guide hole formed in the seating part while the first coupling part and the second coupling part are seated on the seating bottom part, and wherein the bush has key grooves formed at 90-degree intervals along the circumference of the outer surface of the bush in the seating groove.

Description

Technology Field

[0001] The present invention relates to an airfoil journal bearing with improved fastening force, and more specifically, to an airfoil journal bearing with improved fastening force that enables bearing assembly without a process such as welding and prevents the detachment of a bump foil provided inside a bush. Background Technology

[0002] Airfoil bearings are coupled to the rotating shafts of various types of turbo machines and utilize a basic principle in which compressed air generated during the rotation of the shaft is directed into the space between the shaft and the bearing, thereby causing the shaft to be levitated within the bearing by the force of the air.

[0003] These airfoil bearings are primarily used in high-speed turbomachines that rotate at very high speeds. They are widely used because they do not require lubrication, allowing for easy maintenance, and offer excellent load-bearing capacity.

[0004] Among these airfoil bearings, airfoil journal bearings are generally manufactured by welding together a bush, a bump foil, and a top foil. However, when manufactured through welding, there is a disadvantage that the bump foil and top foil cannot be replaced if they wear out or break.

[0005] As a technology capable of compensating for these disadvantages, Korean Registered Patent Publication No. 10-2181517 (detachable airfoil journal bearing) has been disclosed.

[0006] The disclosed detachable airfoil journal bearing is an airfoil journal bearing used in a turbomachine or air cycle machine, comprising: a bump foil (10) having a folded portion (110) formed by repeatedly folding a thin plate for manufacturing a bump foil (10) at a predetermined interval, a connecting portion (120, 210) formed extending at a predetermined acute angle at one end, and a coupling portion (130, 220) formed extending from the connecting portion (120, 210) parallel to the folded portion (110); The apparatus comprises: a top (20) formed with a width and length corresponding to the bump foil (10) and provided with a connecting part (120, 210) and a connecting part (130, 220) corresponding to the connecting part (120, 210) and the connecting part (130, 220); and a bush (30) on which the bump foil (10) and the top (20) are seated on an inner surface, wherein at one end there is a bottom fixing part that fixes the position of the bump foil (10) and the top (20), and a fixing seating part formed in intaglio on the outer surface so that the connecting part (120, 210) and the connecting part (130, 220) pass through and are fixedly coupled at a predetermined position; wherein the bump foil (10) is positioned on the inner surface of the top (20), and the top (20) and the bump foil (10) are positioned on the inner surface of the bush (30), and the It includes a detachable airfoil journal bearing characterized by the connecting portion (120, 210) and the coupling portion (130, 220) being provided to be detachably attached to the fixed seating portion by a predetermined coupling member (40).

[0007] However, with the airfoil journal bearing described above, when the rotating shaft of the turbomachine rotates, one end of the bump foil can be connected and fixed through a connecting member, but the other end is left unfixed, causing a problem where it detaches from inside the bush.

[0008] If the bump foil detaches from the inside of the bush, the top foil rotating together with it may wear out rapidly, and since this wear can shorten the bearing's lifespan, there is a need for technology to prevent the bump foil from detaching. The problem to be solved

[0009] The problem that the present invention aims to solve is to provide an airfoil journal bearing with improved fastening force that can easily fix both ends of a bump foil without welding to prevent the bump foil from detaching, in order to solve the conventional problems described above.

[0010] The technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0011] The airfoil journal bearing with improved fastening force according to the present invention, as a means of solving the problem to achieve the above objective, is an airfoil journal bearing installed on a rotating shaft of a turbomachine or air cycle machine, comprising: a bush formed in the shape of a ring made of aluminum, having a predetermined receiving space in which the rotating shaft is inserted in the inner diameter, a seating portion formed on the outer surface, and a seating groove that opens the receiving space toward the seating portion; and a bump foil having a bent portion that is repeatedly bent at a predetermined interval, rolled up and embedded in the receiving space of the bush, with one end inserted into the seating portion, and a first coupling portion formed extending parallel to the bent portion so as to be fixed to a seating bottom portion formed in the seating portion. The present invention provides an airfoil journal bearing with improved fastening force, comprising: a top foil formed with a width and length corresponding to the bump foil and seated on the inner surface of the bump foil, and having a second coupling part corresponding to the first coupling part; wherein the bush, bump foil, and top foil are detachably provided by fastening a coupling member to a guide hole formed in the seating part while the first coupling part and the second coupling part are seated on the seating bottom part, and wherein the bush has key grooves formed at 90-degree intervals along the circumference of the outer surface of the bush in the seating groove.

[0012] In addition, the present invention provides an airfoil journal bearing with improved fastening force, characterized in that when fastening is performed with a first coupling portion formed at one end of the bump foil seated on the seated bottom portion, the seated wall portion formed on the seated portion and the two ends of the first coupling portion are spaced apart, thereby forming a predetermined gap on both sides of the seated groove.

[0013] In addition, an airfoil journal bearing with improved fastening force is provided, characterized in that an anti-detachment portion is formed at the other end of the bump foil, extending to a width corresponding to the gap formed on both sides of the seating groove.

[0014] In addition, an airfoil journal bearing with improved fastening force is provided, characterized in that wall coupling portions are formed at both ends of the above-mentioned anti-detachment portion and are fitted into predetermined gaps formed on both sides of the above-mentioned seating groove.

[0015] In addition, the above bump foil is configured by combining two or more in a direction orthogonal to the axis center, wherein the bend portions of each of the two or more bump foils are arranged in an alternating manner, and the above anti-detachment member is provided on one or more of the two or more bump foils. This provides an air foil journal bearing with improved fastening force.

[0016] In addition, the above bump foil is configured by combining two or more in a direction orthogonal to the axis center, wherein the fold portions of each of the two or more bump foils are arranged in an alternating manner, and an insertion fixing portion extending to a predetermined width is formed at the other end of each bump foil embedded inside the bushing, thereby providing an air foil journal bearing with improved fastening force.

[0017] In addition, the present invention provides an airfoil journal bearing with improved fastening force, characterized in that the insertion fixing portions are arranged to face each other at the other ends of each bump foil, and when the bump foil is embedded inside the bush, the end of the insertion fixing portion is formed with a length such that it can be inserted between one end of the bump foil and the bush. Effects of the invention

[0018] The airfoil journal bearing with improved fastening force according to the present invention, as described above, allows for the rapid assembly of the bush, bump foil, and top foil without complex processes such as welding, and enables easy and convenient replacement even if the bump foil and top foil are worn or damaged.

[0019] In addition, since it prevents the bump foil from coming off inside the bush when the turbomachine's rotating shaft rotates, maintenance costs for the bearing are reduced and long-term use is possible.

[0020] And the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0021] Figure 1 is a drawing showing an air blower product. FIG. 2 is a drawing showing an air blower equipped with an airfoil journal bearing with improved fastening force according to an embodiment of the present invention. Figure 3 is a drawing showing the appearance of a conventional airfoil journal bearing. Figure 4 is a drawing showing the bump foil of a conventional airfoil journal bearing detached. FIG. 5 is a diagram showing the configuration of an airfoil journal bearing with improved fastening force according to an embodiment of the present invention. FIG. 6 is a diagram showing the experimental results of an airfoil journal bearing with improved fastening force according to an embodiment of the present invention. FIG. 7 is a perspective view of an airfoil journal bearing with improved fastening force according to an embodiment of the present invention. FIG. 8 is a partial enlarged view of an airfoil journal bearing with improved fastening force according to an embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, various embodiments of this document are described with reference to the accompanying drawings. However, this is not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives to the embodiments of this document. In relation to the description of the drawings, similar reference numerals may be used for similar components.

[0023] In this document, expressions such as "have," "can have," "include," or "can include" refer to the existence of the relevant feature (e.g., numerical values, functions, actions, or components, etc.) and do not exclude the existence of additional features.

[0024] In this document, expressions such as “A or B,” “at least one of A or / and B,” or “one or more of A or / and B” may include all possible combinations of items listed together. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” may refer to cases including (1) at least one A, (2) at least one B, or (3) both at least one A and at least one B.

[0025] The terms used in this document are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this document. Terms used in this document that are defined in general dictionaries may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this document. In some cases, even terms defined in this document may not be interpreted to exclude the embodiments of this document.

[0026] It is understood that various modifications can be made by those skilled in the art without departing from the essence of the invention as claimed in the claims of the present invention, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.

[0027] According to an embodiment of the present invention, an air foil journal bearing installed on a rotating shaft of a turbomachine or air cycle machine comprises: a bush (10) formed in the shape of a ring made of aluminum material, having a predetermined receiving space (13) in which the rotating shaft is inserted into the inner diameter, a seating portion (11) formed on the outer surface, and a seating groove (11d) that opens the receiving space (13) toward the seating portion (11); and a bump foil (20) having a bent portion (23) in a state where the bent shape is repeated at a predetermined interval, which is rolled up and embedded in the receiving space (13) of the bush (10), and one end inserted into the seating portion (11), and a first coupling portion (21) formed extending parallel to the bent portion (23) so as to be fixed to a seating bottom portion (11b) formed on the seating portion (11). The present invention provides an air foil journal bearing with improved fastening force, comprising: a top foil (30) formed with a width and length corresponding to the bump foil (20) and seated on the inner surface of the bump foil (20), and having a second coupling part (31) corresponding to the first coupling part (21); wherein the bush (10), bump foil (20), and top foil (30) are detachably provided by fastening a coupling member (12) to a guide hole (11c) formed in the seating part (11) while the first coupling part (21) and the second coupling part (31) are seated on the seating bottom part (11b); and wherein the bush (10) is characterized in that a key groove (14) is formed at 90-degree intervals along the circumference of the outer surface of the bush (10) from the seating groove (11d).

[0028] The airfoil journal bearing with improved fastening force according to the present invention can be configured by fastening a bush (10), a bump foil (20), and a top foil (30), and can be configured to be detachable through a fastening structure of a first coupling part (21) and a second coupling part (31) formed on the seating part (11) of the bush (10) and the bump foil (20) and the top foil (30).

[0029] In the first coupling part (21) and the second coupling part (31), a first through hole (22) and a second through hole (32) into which the coupling member (12) is inserted may be formed to realize the above-mentioned fastening structure.

[0030] In the case of a conventional airfoil journal bearing, the width of the fastening configuration corresponding to the first coupling part (21) and the second coupling part (31) of the present invention is configured to be the same as the width of the bump foil (20) and the top foil (30) and is fastened to the bush (10). Since the part that fixes the bush (10), the bump foil (20), and the top foil (30) is configured to be very wide, the fastening part cannot move flexibly with respect to the rotation of the rotation axis, resulting in a problem of severe noise / vibration / wear.

[0031] In the applicant's prior art, to solve these problems, as shown in FIG. 3(a) and FIG. 3(b), the bump foil (20) and top foil (30) are fastened to the bush (10) through the coupling member (12) and the guide hole (11c), thereby being fixed to the bush (10) by point contact rather than surface contact, and the widths of the first coupling part (21) and the second coupling part (31) are formed narrower than the widths of the bump foil (20) and top foil (30), so that the bush (10), bump foil (20), and top foil (30) are configured to be in a more flexible coupling state than conventional bearings.

[0032] Through this configuration, the fluidity of the bump foil (20) was increased, which could reduce the occurrence of noise / vibration / wear. However, as shown in FIG. 3, the first connecting part (21) and the second connecting part (31) of the bump foil (20) were connected to a connecting part (A) that is extended at a predetermined acute angle, so a situation occurred where the fastening force between the bump foil (20) and the bush (10) was somewhat weakened. As a result, as shown in FIG. 4, the other end of the bump foil (20) was detached from the bush (10), and when the other end of the bump foil (20) was detached from the bush (10), the wear of the top foil (30) proceeded rapidly, causing a problem of reduced bearing life.

[0033] Accordingly, the applicant removed the configuration of the connecting part (A) formed at an acute angle connected to the first connecting part (21) and the second connecting part (31) as shown in FIG. 5, and moved the Key groove (14), which was formed at the 6 o'clock direction in FIG. 3 (b), to the 3 o'clock direction.

[0034] As a result of testing with the above configuration, as shown in FIG. 6, the phenomenon of the bump foil (20) coming out of the bush (10) was reduced, significantly reducing the defect rate, and assembly became easier due to the removal of the connecting part (A).

[0035] Additionally, an airfoil journal bearing with improved fastening force is provided, characterized in that when the first coupling portion (21) formed at one end of the bump foil (20) is fastened while being seated on the seating bottom portion (11b), the seating wall portion (11a) formed on the seating portion (11) and the two ends of the first coupling portion (21) are spaced apart, thereby forming a predetermined gap on both sides of the seating groove (11d).

[0036] In addition, an airfoil journal bearing with improved fastening force is provided, characterized in that an anti-detachment portion (25) is formed at the other end of the bump foil (20) and extends to a width corresponding to the gap formed on both sides of the seating groove (11d).

[0037] In addition, an airfoil journal bearing with improved fastening force is provided, characterized in that a wall coupling part (24) is formed at both ends of the above-mentioned anti-detachment part (25) and is fitted into a predetermined gap formed on both sides of the above-mentioned seating groove (11d).

[0038] As shown in FIG. 8, the other end of the bump foil (20) may be provided with a detachment prevention part (25), and the wall joint part (24) formed on the detachment prevention part (25) may be configured to be fitted into a predetermined gap formed on both sides of the seating groove (11d).

[0039] The above wall coupling part (24) can be seated on the mounting wall part (11a) by being fitted into a predetermined gap formed on both sides of the mounting groove (11d). By fitting the wall coupling part (24) into the mounting wall part (11a) while seated thereon, the other end of the bump foil (20) can be fixed without detaching from the bush (10) when the rotating shaft of the turbo machine rotates. In addition, when the first coupling part (21) and the second coupling part (31) are fastened through the coupling member (12) while seated on the mounting bottom part (11b), the wall coupling part (24) is fitted into a predetermined gap formed on both sides of the mounting groove (11d) and can tightly grip both ends of the first coupling part (21) and the second coupling part (31), thereby increasing the fastening force and reducing vibrations generated in the bearing.

[0040] Additionally, the bump foil (20) is configured by combining two or more of them in a direction orthogonal to the axis center, wherein the bend portions (23) of each of the two or more bump foils (20) are arranged in an alternating manner, and the anti-detachment portion (25) is provided on one or more of the two or more bump foils (20), thereby providing an air foil journal bearing with improved fastening force.

[0041] The above bump foil (20) may be composed of two or more combined parts, and each bump foil (20) may be provided with the anti-detachment part (25), or only one bump foil (20) may be provided with the anti-detachment part (25).

[0042] The number of the above anti-detachment parts (25) can be configured by adjusting it according to the user's discretion, as long as the bump foil (20) does not detach to the side of the bush (10).

[0043] FIGS. 9 and FIGS. 10 are drawings showing the configuration of an airfoil journal bearing with improved fastening force according to another embodiment.

[0044] As shown in FIGS. 9 and 10, an insertion fixing part (26) extending to a predetermined width may be formed at the other end of each bump foil (20) embedded inside the bush (10).

[0045] The above insertion fixing part (26) can be positioned to face each other at the other end of each bump foil (20), and when the bump foil (20) is embedded inside the bush (10), the end of the insertion fixing part (26) can be formed with a length such that it can be inserted between one end of the bump foil (20) and the bush (10).

[0046] When the insertion fixing part (26) is inserted between one end of the bump foil (20) and the bush (10) and the bush (10) is connected through the coupling member (12), the insertion fixing part (26) can be fixed by the pressure applied by one end of the bump foil (20), and even if the rotation axis rotates inside the bush (10), the other end of the bump foil (20) can be fixed in the correct position without deviating from the bush (10).

[0047] For convenience, a groove of a predetermined depth may be formed on the inner surface of the bush (10) into which the insertion fixing part (26) is inserted so that the insertion fixing part (26) can be easily inserted.

[0048] The foregoing description has broadly detailed the features and technical advantages of the present invention to better facilitate a better understanding of the claims of the invention to be described below. Those skilled in the art will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the claims and their equivalents should be interpreted as being included within the scope of the present invention.

[0049] Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. Explanation of the symbols

[0050] A : Connection 1 : Airfoil journal bearing 10 : Bush 11 : Landing 11a: Mounting wall 11b: Mounting bottom 11c : Guide hole 11d : Seating groove 12 : Connecting member 13 : Receiving space 14 : Key Home 20 : Bump Foil 21: First connecting part 22: First penetrating hole 23 : Bent section 24 : Wall joint section 25: Anti-detachment part 26: Insertion fixing part 30 : Top foil 31 : Second connecting part 32: Second penetration hole

Claims

Claim 1 An airfoil journal bearing installed on a rotating shaft of a turbomachine or air cycle machine, comprising: a bush formed in the shape of a ring made of aluminum, having a predetermined receiving space in its inner diameter into which the rotating shaft is inserted, a seating portion formed on its outer surface, and a seating groove that opens the receiving space toward the seating portion; and a bump foil having a bent portion that is rolled up and embedded in the receiving space of the bush, wherein one end is inserted into the seating portion, and a first coupling portion is formed extending parallel to the bent portion so as to be fixed to a seating bottom portion formed in the seating portion. and a top foil formed with a width and length corresponding to the bump foil and seated on the inner surface of the bump foil, and provided with a second coupling part corresponding to the first coupling part; wherein the bush, bump foil, and top foil are provided to be detachably connected by fastening a coupling member to a guide hole formed in the seating bottom part while the first coupling part and the second coupling part are seated thereon, and wherein the bump foil is configured such that two or more are joined in a direction orthogonal to the axis center, and the fold portions of each of the two or more bump foils are arranged to be staggered from each other, and an insertion fixing part extending to a predetermined width is formed at the other end of each bump foil embedded inside the bush, and wherein the insertion fixing part is configured to be inserted between one end of the bump foil and the bush while the bump foil is embedded inside the bush, and is interposed between a plurality of first coupling parts formed on one end of the bump foil and supported by the first coupling parts, thereby suppressing the detachment of the other end of the bump foil. An airfoil journal bearing with improved fastening force, characterized in that a groove of a predetermined depth is formed on the inner surface of a bush at the position where the insertion fixing part is inserted, and key grooves are formed in the bush at 90-degree intervals along the circumference of the outer surface of the bush from the seating groove. Claim 2 An airfoil journal bearing with improved fastening force according to claim 1, characterized in that when fastening is performed with a first coupling portion formed at one end of the bump foil seated on the seated bottom portion, the seating wall portion formed on the seated portion and the two ends of the first coupling portion are spaced apart, thereby forming a predetermined gap on both sides of the seating groove. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete

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