JP6246574B2 - Foil bearing unit and turbomachine - Google Patents

Description

  The present invention relates to a rotating member fixed to a shaft and rotatably supported by a foil bearing, a foil bearing unit having the same, and a turbo machine.

  A bearing that supports a main shaft of a turbo machine such as a gas turbine or a turbocharger is required to withstand a severe environment such as high temperature and high speed rotation. As a bearing suitable for use under such conditions, a foil bearing has attracted attention. In the foil bearing, a bearing surface is constituted by a thin film (foil) having low rigidity with respect to bending, and the load is supported by allowing the bearing surface to bend. When the shaft rotates, a fluid film (for example, an air film) is formed between the outer peripheral surface of the shaft and the bearing surface of the foil, and the shaft is supported in a non-contact manner.

  For example, Patent Document 1 and Patent Document 2 below show a turbo machine to which a foil bearing is applied. In these turbo machines, rotating members are fixed to the turbine shaft, and these are rotatably supported by foil bearings. The rotating member has a flange portion protruding to the outer diameter, and this flange portion is supported in the thrust direction by a foil bearing.

JP 9-510522 A Japanese National Patent Publication No. 10-511446

  When the turbine shaft of the turbomachine rotates at high speed, centrifugal force is applied to the rotating member. In particular, as described above, when the rotating member is provided with the flange portion protruding to the outer diameter, a large centrifugal force is applied to the flange portion as the turbine shaft rotates. When such a rotating member is formed of a metal material (for example, stainless steel), the weight of the flange portion increases, and the moment of inertia of the rotating member, and hence the turbine shaft, increases. Turbomachines, particularly turbochargers, are required to have high rotational responsiveness with respect to engine output. However, when the moment of inertia of the turbine shaft increases as described above, rotational responsiveness decreases. Moreover, since the centrifugal force added to a rotating member will become large when the weight of a rotating member is large, there exists a possibility that a rotating member may be damaged by a centrifugal force.

  An object of the present invention is to improve the rotational responsiveness and centrifugal strength (strength against centrifugal force) of a rotating member supported by a foil bearing.

  In order to achieve the above object, the present invention provides a rotating member fixed to a shaft and rotatably supported by a foil bearing, at least a part of which is formed of a carbon fiber reinforced composite material.

  Thus, by forming at least a part of the rotating member with the carbon fiber reinforced composite material, it is possible to reduce the weight of the rotating member as compared with the case of forming with a metal material. As a result, the moment of inertia of the rotating member is reduced, and the rotational responsiveness of the rotating member, and thus the shaft (for example, the turbine shaft) to which the rotating member is attached is enhanced. Further, since the centrifugal force applied to the rotating member is reduced by reducing the weight of the rotating member, the centrifugal strength of the rotating member is improved. In particular, if a composite material (C / C composite) of carbon fiber and carbon or graphite matrix is used as the carbon fiber reinforced composite material, the heat resistance is improved and the lubricity of carbon (graphite) constituting the base material is increased. This improves the slidability.

  Said rotating member can be made into the structure provided with the flange part supported by a thrust foil bearing in a thrust direction. Since the flange portion has a large outer diameter, the influence on the moment of inertia of the rotating member is relatively large, and the centrifugal force applied during rotation is also relatively large. In such a case, it is preferable that the flange portion is formed of a carbon reinforced fiber composite material.

  Further, the rotating member may have a structure further including a sleeve portion supported in the radial direction by a radial foil bearing. Since the sleeve portion has a smaller outer diameter than the flange portion, the influence on the moment of inertia of the rotating member is relatively small, and the centrifugal force applied during rotation is also relatively small. As described above, since the required characteristics are different between the flange portion and the sleeve portion, it is preferable to form them with different materials, that is, materials according to the respective properties. For example, when the sleeve portion is used in an application where the sleeve portion is frequently in contact with the radial foil bearing, if the sleeve portion is formed of a carbon fiber reinforced composite material, the base material is worn earlier than the carbon fiber on the outer peripheral surface of the sleeve portion. In this case, the carbon fiber protrudes relatively from the outer peripheral surface of the sleeve portion, which increases the aggressiveness to the radial foil bearing and may reduce the wear resistance. Therefore, if the sleeve portion is formed of a carbon sintered material, the slidability with the radial foil bearing can be enhanced by the solid lubricating action of carbon (graphite), and the outer peripheral surface of the sleeve portion can be evenly worn. Abrasion resistance can be increased.

  The rotating member as described above is fixed to a shaft arranged in the horizontal direction, for example. In this case, the fluid pressure between the foil bearing and the rotating member is low during low-speed rotation such as when the shaft is started and stopped, so the shaft and the rotating member descend due to gravity, and the outer peripheral surface of the sleeve portion and the radial foil bearing Contact (so-called touchdown) occurs. For this reason, high abrasion resistance is requested | required by the outer peripheral surface of a sleeve part. On the other hand, since the contact between the end face of the flange portion and the thrust foil bearing is relatively small, the flange portion is not required to have high wear resistance. Therefore, when the rotating member is fixed to the horizontal shaft, it is particularly preferable that the flange portion is formed of a carbon fiber reinforced composite material and the sleeve portion is formed of a carbon sintered material as described above.

  Since the end surface of the flange portion and the outer peripheral surface of the sleeve portion face the bearing surfaces of the thrust foil bearing and the radial foil bearing, respectively, their relative positional accuracy (perpendicularity, coaxiality, etc.) is important. For example, if the flange portion and the sleeve portion are formed separately and are separately fixed to the shaft, the relative positional accuracy between the end surface of the flange portion and the outer peripheral surface of the sleeve portion may deteriorate during assembly. . Therefore, if the flange portion and the sleeve portion are integrated in advance in a state in which the flange portion and the sleeve portion are in contact with each other in the axial direction, it is possible to prevent the relative positional accuracy of the two from being deteriorated when assembled to the shaft. Furthermore, if it integrates in the state which fitted the inner peripheral surface of the flange part, and the outer peripheral surface of the sleeve part, both relative positional accuracy and coupling | bonding force can be improved further.

  If the above-mentioned rotating member and the foil bearing that rotatably supports the rotating member are unitized as a foil bearing unit, the rotating member and the foil bearing can be handled integrally, so that it can be easily assembled to a turbo machine or the like. be able to.

  The rotating member as described above can be suitably used for supporting rotation of a shaft that rotates at a high speed, for example, a turbine shaft of a turbomachine.

  As described above, according to the present invention, the rotational responsiveness and centrifugal strength of the rotating member can be improved by forming the flange portion with the carbon fiber reinforced composite material.

It is a figure which shows notionally the structure of a gas turbine. It is sectional drawing which shows the support structure of the rotor in the said gas turbine. It is sectional drawing of the foil bearing unit which concerns on one Embodiment of this invention integrated in the said support structure. It is sectional drawing of the radial foil bearing integrated in the said foil bearing unit. (A) is a perspective view of the foil of the radial foil bearing, and (B) is a perspective view of a state in which three foils are temporarily assembled. It is a top view of the foil and foil holder of a thrust foil axis | shaft. (A) is a top view of a 1st thrust foil bearing, (B) is a top view of a 2nd thrust foil bearing. It is sectional drawing of a 1st thrust foil bearing. It is sectional drawing which shows the other example of a rotation member. It is sectional drawing which shows the further another example of a rotation member.

  FIG. 1 conceptually shows the configuration of a gas turbine that is a kind of turbomachine. This gas turbine mainly includes a turbine 1 and a compressor 2 that form blade cascades, a generator 3, a combustor 4, and a regenerator 5. The turbine 1, the compressor 2, and the generator 3 are provided with a common shaft 6 that extends in the horizontal direction, and the shaft 6, the turbine 1, and the compressor 2 constitute a rotor that can rotate integrally. Air sucked from the intake port 7 is compressed by the compressor 2, heated by the regenerator 5, and then sent to the combustor 4. Fuel is mixed with this compressed air and burned, and the turbine 1 is rotated by high-temperature and high-pressure gas. The rotational force of the turbine 1 is transmitted to the generator 3 via the shaft 6, and the generator 3 rotates to generate electric power, and this electric power is output via the inverter 8. Since the gas after rotating the turbine 1 is at a relatively high temperature, the heat of the gas after combustion is regenerated by sending this gas to the regenerator 5 and exchanging heat with the compressed air before combustion. Use. The gas that has been subjected to heat exchange in the regenerator 5 is discharged as exhaust gas after passing through the exhaust heat recovery device 9.

  FIG. 2 shows a foil bearing unit 10 that supports the rotor shaft 6 in the gas turbine. The foil bearing unit 10 includes a rotating member 20 fixed to the shaft 6, a radial foil bearing 30 that supports the shaft 6 and the rotating member 20 in the radial direction, and a first thrust that supports the shaft 6 and the rotating member 20 in the thrust direction. A foil bearing 40 and a second thrust foil bearing 50 are provided.

  As shown in FIG. 3, the rotating member 20 includes a sleeve portion 21 and a disk-like flange portion 22 that protrudes from the sleeve portion 21 to the outer diameter. In the example of illustration, the flange part 22 is provided in the axial direction edge part by the side of the compressor 2 of the sleeve part 21 (left side of FIG. 3). The rotating member 20 is at least partially formed of a carbon fiber reinforced composite material. In the present embodiment, the sleeve portion 21 and the flange portion 22 of the rotating member 20 are formed separately and are formed of different materials. The flange portion 22 is formed of a carbon fiber reinforced composite material, in particular, a composite material (C / C composite) of carbon fiber and carbon or graphite matrix. C / C composites are impregnated by impregnating a matrix made of carbon fiber with a matrix such as a resin, and then firing to carbonize the matrix (graphitize if necessary), It is formed by a CVD method in which carbon obtained by pyrolyzing hydrocarbons is deposited. The sleeve portion 21 is formed of, for example, a sintered material. In the present embodiment, the sleeve portion 21 is formed of a carbon sintered material obtained by firing carbon powder (particularly graphite powder).

  The sleeve portion 21 and the flange portion 22 are integrated in a state where they are in contact with each other in the axial direction. Specifically, in a state where the end surface 21c of the sleeve portion 21 and the end surface 22c provided at the inner diameter end of the flange portion 22 are in contact with each other in the axial direction, both are fixed by appropriate means such as adhesion or welding. . The rotating member 20 integrated in this way is fitted and fixed to the outer peripheral surface of the shaft 6, specifically, press-fitted and fixed. In this way, by integrating the sleeve portion 21 and the flange portion 22 in advance, the sleeve 6 and the flange portion 22 can be assembled to the shaft 6 in a state in which the relative position (perpendicularity, coaxiality, etc.) of the two is set with high accuracy.

  As shown in FIG. 4, the radial foil bearing 30 includes a cylindrical foil holder 31 and a plurality of foils 32 attached to the inner peripheral surface of the foil holder 31. A groove 31 b into which the circumferential end of the foil 32 is inserted is formed on the inner peripheral surface 31 a of the foil holder 31. The grooves 31b extend over the entire length in the axial direction of the foil holder 31 and are provided at a plurality of locations (three locations in the illustrated example) at equal intervals in the circumferential direction.

  The plurality of foils 32 are attached to the inner peripheral surface 31a of the foil holder 31 in a state of being arranged in the circumferential direction. The inner diameter surface 32a of each foil 32 functions as a radial bearing surface S1. In the illustrated example, a multi-arc radial bearing surface S1 is formed by three foils 32. No member (back foil or the like) for imparting elasticity to the foil 32 is provided between the inner peripheral surface 31a of the foil holder 31 and each foil 32, and the outer diameter surface 32b of the foil 32 and the foil holder. The inner peripheral surface 31a of 31 can be slid.

  As shown in FIG. 5A, each foil 32 includes a convex portion 32c provided at one end in the circumferential direction and a concave portion 32d provided at the other circumferential end. The convex portion 32c and the concave portion 32d of each foil 32 are provided at the same position in the axial direction. As shown in FIG. 5B, the three foils 32 can be temporarily assembled into a cylindrical shape by fitting the convex portions 32c of the foils 32 into the concave portions 32d of the adjacent foils 32. In this case, when viewed in the axial direction shown in FIG. 4, one end in the circumferential direction (convex portion 32c) of each foil 32 intersects with the other circumferential end of the adjacent foil 32 (convex portions 32e on both sides in the axial direction of the concave portion 32d). It will be in the state. In the present embodiment, the convex portion 32 e at the other circumferential end of each foil 32 is inserted into the groove 31 b provided on the inner peripheral surface 31 a of the foil holder 31. A convex portion 32c at one circumferential end of each foil 32 is disposed between the outer diameter surface 32b of the adjacent foil 32 and the inner peripheral surface 31a of the foil holder 31, and functions as an underfoil portion.

  As shown in FIG. 3, the first thrust foil bearing 40 supports the flange portion 22 of the rotating member 20 from one side in the axial direction (right side in the figure), and includes a disc-shaped foil holder 41 and a foil holder 41. And a plurality of foils 42 fixed to the end face 41a. In the present embodiment, the foil holder 41 of the first thrust foil bearing 40 and the foil holder 31 of the radial foil bearing 30 are integrally formed.

  As shown in FIG. 6, each foil 42 of the first thrust foil bearing 40 includes a main body portion 42a, a fixing portion 42b provided on the outer diameter side of the main body portion 42a, a main body portion 42a, and a fixing portion 42b. A connecting portion 42c to be connected is integrally provided. The rotation direction of the main body 42a (the rotation direction of the shaft 6, the same applies hereinafter) The leading edge 42d and the rotation direction rear edge 42e are both substantially V-shaped with the central portion protruding toward the rotation direction leading side. ing. The central portions of the edges 42d and 42e of the main body 42a are rounded in an arc shape.

  The fixing portion 42b of each foil 42 is fixed to the outer diameter end of the end surface 41a of the foil holder 41 as shown in FIG. In the illustrated example, the fixing portions 42 b of the plurality of foils 42 are arranged on the same circumference, and the entire fixing portion 42 b is sandwiched and fixed by the ring-shaped fixing member 43 and the end surface 41 a of the foil holder 41. The plurality of foils 42 are arranged at equal pitches in the circumferential direction. In the illustrated example, the foils 42 are overlapped with a phase shifted by half of each foil 42. As shown in FIG. 8, the edge 42 d on the front side in the rotation direction of each foil 42 is disposed on the adjacent foil 42 (on the flange portion 22 side). That is, the rotation direction leading side portion of each foil 42 rides on the rotation direction rear side portion of the adjacent foil 42. Of the surface of the main body portion 42a of each foil 42, the portion that directly faces one end surface 22a of the flange portion 22 (the portion visible in FIG. 7A) functions as the thrust bearing surface S2. In addition, you may fix the fixing | fixed part 42b of each foil 42 to the foil holder 41 or the fixing member 43 by welding or adhesion | attachment.

  As shown in FIG. 3, the second thrust foil bearing 50 supports the flange portion 22 of the rotating member 20 from the other axial side (left side in the drawing). As shown in FIG. 7B, the second thrust foil bearing 50 includes a disc-shaped foil holder 51 and a plurality of foils 52 fixed to the end surface 51 a of the foil holder 51. Of the surface of the main body portion of each foil 52, the portion (the portion visible in FIG. 7B) that directly faces the other end surface 22b of the flange portion 22 functions as the thrust bearing surface S3. Since the other structure of the 2nd thrust foil bearing 50 is the same as that of the 1st thrust foil bearing 40, duplication description is abbreviate | omitted.

  The foils 32, 42, and 52 are subjected to press working, wire cutting, etching, or the like on a metal foil having a high spring property and good workability, for example, a metal foil made of a steel material or a copper alloy and having a thickness of about 20 μm to 200 μm. Formed with. In an air dynamic pressure bearing using air as a fluid film as in this embodiment, since there is no lubricating oil in the atmosphere, it is preferable to use a stainless steel or bronze metal foil.

  The foil bearing unit 10 having the above configuration is assembled in the following procedure. First, the sleeve portion 21 of the rotating member 20 is inserted into the inner periphery of the radial foil bearing 30. Thereafter, the second thrust foil bearing 50 is attached to the first thrust foil bearing 40 so as to sandwich the flange portion 22 of the rotating member 20 from both axial sides. Specifically, the fixing member 43 attached to the foil holder 41 of the first thrust foil bearing 40 and the fixing member 53 attached to the foil holder 51 of the second foil bearing 50 are contacted in the axial direction, and in this state, The foil holders 41 and 51 are fixed with bolts (not shown). Thus, the foil bearing unit 10 is completed.

  In the foil bearing unit 10 having the above-described configuration, the shaft 6 is press-fitted into the inner periphery of the rotating member 20, and part or all of the foil holders 31, 41, 51 of the foil bearings 30, 40, 50 are fixed to the housing of the gas turbine. By doing so, it is assembled to the gas turbine. At this time, since the sleeve portion 21 and the flange portion 22 of the rotating member 20 are integrated in advance, their relative positional accuracy, specifically, the outer peripheral surface 21a of the sleeve portion 21 and both end surfaces of the flange portion 22 The rotating member 20 can be attached to the shaft 6 in a state in which the perpendicularity to 22a and 22b is set with high accuracy. Further, in the foil bearing unit 10, the rotating member 20 is accommodated inside the bearing member constituted by the radial foil bearing 30 and the thrust foil bearings 40 and 50, and separation between the bearing member and the rotating member 20 is regulated. Since these are integrated, the bearing member and the rotating member 20 can be handled integrally when assembling to the gas turbine, and the assemblability is improved.

  When the shaft 6 rotates in one circumferential direction (the arrow direction in FIGS. 4 and 7), the radial bearing surface S1 of the foil 32 of the radial foil bearing 30 and the outer peripheral surface 21a of the sleeve portion 21 of the rotating member 20 are radially A bearing gap is formed, and the rotary member 20 and the shaft 6 are supported in the radial direction by the pressure of the air film generated in the radial bearing gap. At the same time, between the thrust bearing surface S2 of the foil 42 of the first thrust foil bearing 40 and one end surface 22a of the flange portion 22 of the rotating member 20, and the thrust bearing surface of the foil 52 of the second thrust foil bearing 50. A thrust bearing gap is formed between S3 and the other end face 22b of the flange portion 22 of the rotating member 20, and the rotating member 20 and the shaft 6 are supported in both thrust directions by the pressure of the air film generated in each thrust bearing gap. Is done.

  At this time, due to the flexibility of the foils 32, 42, 52, the bearing surfaces S 1, S 2, S 3 of the foils 32, 42, 52 depend on the operating conditions such as the load, the rotational speed of the shaft 6, and the ambient temperature. In order to deform arbitrarily, the radial bearing gap and the thrust bearing gap are automatically adjusted to appropriate widths according to the operating conditions. Therefore, even under severe conditions such as high temperature and high speed rotation, the radial bearing gap and the thrust bearing gap can be managed to the optimum width, and the rotating member 20 and the shaft 6 can be stably supported.

  Further, as described above, by forming the flange portion 22 of the rotating member 20 with a carbon fiber reinforced composite material, the flange portion 22 can be reduced in weight and tensile strength can be improved. Strength is increased. In particular, when the flange portion 22 has a relatively large diameter (for example, when the diameter of the flange portion 22 is larger than the axial dimension of the sleeve portion 21, see FIG. 3), the flange portion 22 is reinforced with carbon fiber as described above. Forming with a composite material is effective. In particular, by forming the flange portion 22 from a C / C composite, the heat resistance is improved and the lubricity of the carbon (graphite) that forms the base material of the flange portion 22 allows sliding with the thrust foil bearings 40 and 50. Increased mobility.

  Moreover, the slidability with the radial foil bearing 30 is improved by forming the sleeve portion 21 of the rotating member 20 from a carbon sintered material. In particular, as in this embodiment, when the rotating member 20 is fixed to the shaft 6 extending in the horizontal direction, the outer peripheral surface 21a of the sleeve portion 21 is the radial foil bearing 30 when the shaft 6 is rotated at a low speed such as when the shaft 6 is started or stopped. Therefore, it is effective to improve the slidability by forming the sleeve portion 21 with a carbon sintered material.

  In addition, since the bearing surfaces S1 to S3 of the foils and the rotating member 20 are in sliding contact with each other at the time of low-speed rotation immediately before the shaft 6 is stopped or immediately after starting, a DLC film, titanium aluminum nitride is provided on one or both of them. A low friction coating such as a film or a molybdenum disulfide film may be formed. Further, when the shaft 6 rotates, vibrations of the shaft 6 can be suppressed by minute sliding between the foils 32, 42, 52 and the foil holders 31, 41, 51. In order to adjust the frictional force due to this micro-sliding, the above-described low friction coating may be formed on one or both of the foils 32, 42, 52 and the foil holders 31, 41, 51. Good.

  The present invention is not limited to the above embodiment. For example, the rotating member 120 shown in FIG. 9 not only brings the flange portion 22 and the sleeve portion 21 into contact with each other in the axial direction but also fits the inner peripheral surface of the flange portion 22 and the outer peripheral surface of the sleeve portion 21. It is integrated in the state. Specifically, a small-diameter outer peripheral surface 21b is provided on one end side in the axial direction of the outer peripheral surface 21a of the sleeve portion 21, and the small-diameter outer peripheral surface 21b of the sleeve portion 21 is fitted to the inner peripheral surface 22d of the flange portion 22, and the sleeve The shoulder surface (end surface 21 c) between the outer peripheral surface 21 a of the portion 21 and the small-diameter outer peripheral surface 21 b is brought into contact with the end surface 22 c of the flange portion 22.

  Thus, in addition to the contact between the end surface 21c of the sleeve portion 21 and the end surface 22a of the flange portion 22, by fitting the small-diameter outer peripheral surface 21b of the sleeve portion 21 and the inner peripheral surface 22d of the flange portion 22, The relative positional accuracy between the two is further enhanced, and the contact area between the two is increased to increase the coupling force. In particular, in the present embodiment, the radial thickness of the small-diameter outer peripheral surface 21b of the sleeve portion 21 is thinner than other regions. For this reason, since the small-diameter outer peripheral surface 21b is expanded in diameter and pressed against the inner peripheral surface 22d of the flange portion 22 by press-fitting into the shaft 6, the coupling force between the sleeve portion 21 and the flange portion 22 is further enhanced.

  The rotating member 220 shown in FIG. 10 is provided with a protruding portion 21d protruding toward the outer diameter between the outer peripheral surface 21a and the small-diameter outer peripheral surface 21b of the sleeve portion 21, and the end surface 21c of the protruding portion 21d is connected to the flange portion 22. It is made to contact | abut to the end surface 22c of the inner diameter end. Thereby, the contact area of the contact part of the axial direction of the sleeve part 21 and the flange part 22 can be expanded, and both relative positional accuracy and coupling | bonding force can further be improved. In addition, the protrusion part 21d may be provided in the perimeter of the sleeve part 21, and may be provided in the several places spaced apart in the circumferential direction.

  Moreover, in the above embodiment, the case where the sleeve portion 21 of the rotating member 20 is formed of a carbon sintered material and the flange portion 22 is formed of a carbon fiber reinforced composite material has been described. Depending on the characteristics, the part formed of the carbon fiber reinforced composite material may be changed. For example, when the shaft 6 is arranged in the vertical direction (not shown), the end surface 22b (or the end surface 22a) of the flange portion 22 and the thrust foil bearing 50 (or the thrust foil bearing 40) during low speed rotation such as when the shaft is started and stopped. ) And slide. On the other hand, the contact between the outer peripheral surface 21a of the sleeve portion 21 and the radial foil bearing 30 is relatively small. Therefore, when the rotating member 20 is fixed to the vertical shaft 6, the flange portion may be formed of a carbon sintered material having excellent slidability, and the sleeve portion 21 may be formed of a carbon fiber reinforced composite material. .

  Further, in the above embodiment, the sleeve portion 21 and the flange portion 22 of the rotating member 20 are formed separately, but they may be integrally formed with a carbon fiber reinforced composite material.

  Moreover, although the case where the radial foil bearing 30 was comprised with the multi-arc bearing was shown in the above embodiment, it is not restricted to this, While attaching the circumferential direction one end of each foil to the internal peripheral surface 31a of the foil holder 31, Uses a so-called leaf-type radial bearing foil with the other end in the circumferential direction of the foil as a free end, or a so-called bump foil-type radial bearing foil with a corrugated back foil on the outer diameter of a cylindrical top foil. May be. Further, the configuration of the thrust foil bearing is not limited to the above, and, for example, a bump foil type thrust foil bearing in which a wave type back foil is disposed between the top foil and the foil holder may be used.

  The application object of the foil bearing unit 10 according to the present invention is not limited to the gas turbine described above, and can be used as a bearing for supporting a rotor of a supercharger, for example. In addition, the foil bearing according to the present invention is not limited to a turbo machine such as a gas turbine or a turbocharger, and it is difficult to lubricate with a liquid such as a lubricating oil. It can be widely used as a bearing for a vehicle such as an automobile, which is used under a restriction that it is difficult to provide or resistance due to shearing of a liquid becomes a problem, and further, as a bearing for industrial equipment.

  Each of the foil bearings described above is an air dynamic pressure bearing that uses air as a pressure generating fluid. However, the present invention is not limited to this, and other gases can be used as the pressure generating fluid, or water or oil can be used. A liquid such as can also be used.

6 shaft 10 foil bearing unit 20 rotating member 21 sleeve portion 22 flange portion 30 radial foil bearing 31 foil holder 32 foil 40 first thrust foil bearing 41 foil holder 42 foil 43 fixing member 50 second thrust foil bearing 51 foil holder 52 foil 53 Fixed member S1 Radial bearing surface S2 Thrust bearing surface S3 Thrust bearing surface

Claims (7)

A rotating member having a sleeve portion and a flange portion; a radial foil bearing having the sleeve portion inserted into an inner periphery thereof; and a first thrust foil bearing and a second thrust foil bearing disposed on both axial sides of the flange portion. A foil bearing unit comprising a bearing member having
A sleeve portion of the rotating member is fixed to a shaft disposed in a horizontal direction;
A foil bearing unit in which a flange portion of the rotating member is formed of a carbon fiber reinforced composite material. The foil bearing unit according to claim 1, wherein the carbon fiber reinforced composite material is a C / C composite. Foil bearing unit according to claim 1, wherein the formation of said sleeve portion and the flange portion of a different material. The foil bearing unit according to claim 3, wherein the flange portion is formed of a carbon fiber reinforced composite material, and the sleeve portion is formed of a carbon sintered material. The foil bearing unit according to any one of claims 1 to 4 , wherein the flange portion and the sleeve portion are formed separately and integrated in a state in which both are in contact with each other in the axial direction. Furthermore, the foil bearing unit of Claim 5 integrated in the state which fitted the inner peripheral surface of the said flange part, and the outer peripheral surface of the said sleeve part. The turbomachine provided with the foil bearing unit in any one of Claims 1-6 , and the axis | shaft to which the said rotating member was fixed.

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