![]() Combined brush seal and labyrinth seal segment for rotary machines
专利摘要:
A brush seal is comprised of arcuate seal segments having ends cut in a radial direction with bristles “canted” at an approximate 45° angle relative to radii of the segments, leaving triangular regions adjacent one end of each segment devoid of bristles at the segment interfaces. The brush seals are retrofit into conventional labyrinth seals with the backing plate for the bristles comprising a labyrinth tooth profile extending fully 360° about the seal, including those areas where bristles are not present. The sealing capacity is not substantially degraded, while affording significant sealing improvements over conventional labyrinth seals. Additionally, when retrofit into labyrinth seals with radial movement, the individual labyrinth seal segments are free to move radially independently of one another during transients. 公开号:US20010007384A1 申请号:US09/791,881 申请日:2001-02-26 公开日:2001-07-12 发明作者:David skinner;Bharat Bagepalli;Robert Cromer;Osman Dine;Norman Turnquist;Christopher Wolfe 申请人:General Electric Co; IPC主号:F01D11-001
专利说明:
[0001] This application is a continuation-in-part of application Ser. No. 08/672,665, filed Jun. 28, 1996, which in turn is a continuation-in-part of application Ser. No. 08/438,228, filed May 9, 1995, which in turn is a division of application Ser. No. 342,011, filed Nov. 16, 1994, now U.S. Pat. No. 5,474,306 and which in turn is a continuation of application Ser. No. 978,731, filed Nov. 19, 1992, now abandoned, the disclosures of which are incorporated herein by reference. [0001] TECHNICAL FIELD [0002] The present invention relates to brush seals for rotary machines such as steam and gas turbines and particularly relates to brush seals and labyrinth-brush seal combinations for use with rotary machines. [0002] BACKGROUND [0003] Rotary machines, such as steam and gas turbines, used for power generation and mechanical drive applications are generally large machines consisting of multiple turbine stages. In turbines, high pressure fluid flowing through the turbine stages must pass through a series of stationary and rotating components, and seals between the stationary and rotating components are used to control leakage. The efficiency of the turbine is directly dependent on the ability of the seals to prevent leakage, e.g., between the rotor and stator. Turbine designs are conventionally classified as either impulse, with the majority of the pressure drop occurring across fixed nozzles, or reaction, with the pressure drop more evenly distributed between the rotating and stationary vanes. Both designs employ rigid tooth, i.e., labyrinth, seals to control leakage. Traditionally, rigid labyrinth seals of either a hi-lo or straight shaft design are used. These types of seals are employed at virtually all turbine locations where leakage between rotating and stationary components must be controlled. This includes interstage shaft seals, rotor end seals, and bucket (or blade) tip seals. Steam turbines of both impulse and reaction designs typically employ rigid, sharp teeth for rotor/stator sealing. While labyrinth seals have proved to be quite reliable, their performance degrades over time as a result of transient events in which the stationary and rotating components interfere, rubbing the labyrinth teeth into a “mushroom” profile and opening the seal clearance. [0003] [0004] Another type of seal used in many environments, including rotary machines, is a brush seal. Brush seals are generally less prone to leakage than labyrinth seals. A brush seal can also accommodate relative radial movement between fixed and rotational components, for example, between a rotor and a stator, because of the flexure of the seal bristles. Brush seals also generally conform better to surface non-uniformities. The result of using brush seals is better sustained rotary machine performance than is generally possible with labyrinth seals. [0004] DISCLOSURE OF THE INVENTION [0005] In accordance with a preferred embodiment of the present invention, there is provided brush seal segments in the environment of a rotary machine such as a turbine. Brush seals per se have general applicability to rotary machines and can be used in lieu of labyrinth seals. Brush seals are advantageous in that context and provide improved sealing, while occupying considerably less axial space as compared with conventional labyrinth seals. As a result, more compact rotary machine, e.g., turbine, designs can be realized. Alternatively, by employing brush seals, the span that would normally be occupied by labyrinth teeth can be used to allow additional turbine stages, resulting in increased turbine efficiency. As a further advantage, application of brush seals at end packing locations can reduce leakage to the point that the need for a gland sealing/exhauster system, for example, in a steam turbine, is eliminated. At rotor end seals, it is also possible to use brush seals in conjunction with face seals. Further, in certain steam rotary machine applications, some leakage is desirable for cooling of components such as rotors. At these locations, brush seals can be used in conjunction with orifices or other flow bypass mechanisms to ensure that the proper amount of leakage is obtained. [0005] [0006] A typical brush seal for use in the present invention comprises a bristle pack, i.e., bristles sandwiched between two metallic plates. The bristles are generally alloy steel wires, drawn to a diameter of 0.002-0.006 inches, although the exact diameter depends on the specific seal application. Larger wire diameters are used for seals exposed to a high pressure differential between the upstream and downstream sides. The backing (downstream) plate, or in the present invention a labyrinth tooth, prevents the bristles from deflecting axially under pressure load. As a result, fence height (h) is a critical design variable. Fence height is the distance the bristles extend freely from their support, i.e., the distal end of the support plate or contact points between the bristles and the labyrinth tooth, to their free ends, which typically are in engagement with the rotating component. For a steam turbine application, where the expected maximum radial rotor deflection is approximately 0.040 inches, the fence height must therefore be a minimum of 0.040 inches. Fence heights vary significantly, particularly in gas turbines, depending on the seal location, from 0.030 for bearing seals, to 0.120 for high pressure packing seals to 0.300 for turbine interstage seals. [0006] [0007] During shaft radial excursions, the bristles must be able to temporarily deflect without buckling. In order to accommodate these excursions, the bristles are not oriented in a perfectly radial direction, but are instead canted at some angle. Typically, this angle is between 30 and 60 degrees. Increased angles are used to allow for increased radial shaft excursions. If the bristles were straight in a radial direction, the rotor would interfere with the bristles and the bristles would act as columns rather than deflect as beams. This would result in increased wear and not accommodate radial excursions of the shaft. [0007] [0008] The bristles of brush seals are typically mounted between a pair of plates or arcuate segments, with the bristles and plates being welded to one another at the ends of the bristles remote from the tips engaging with the opposite component of the seal. Conventionally, the brush seal is cut into a number of segments, typically four, with the cuts at the ends of each of the segments oriented at the same angle as the “cant” angle of the bristles. That is, with the angle of the bristles typically being on the order of 45° relative to radii of the arcuate segments, the ends of each of the segments are likewise cut at the same angle and therefore parallel the linear extent of the bristles as they project from the segment at that segment end. As a result, the bristles lie at an angle affording the capability of accommodating radial excursions of the rotating component. By cutting the segments of the seal at the angles of the bristles, the bristles may be secured at that angle in the segments without loss of bristles, resulting in an assembled seal with a full 360° of bristles for maximum sealing effectiveness. [0008] [0009] In certain applications, however, for example conventional labyrinth seals, the labyrinth seal segments are generally cut in a radial direction for ease of manufacturing and assembly. Further, when retrofitting brush seals to existing labyrinth seals or supplying brush seals as original equipment in combination with labyrinth seals, it has been found desirable according to the present invention to cut the brush seal segment ends in a radial direction rather than in the direction of the “cant” of the bristles. This results in making surfaces at the segment end interfaces that are perfectly straight along radii of the segments with no interlocking pieces and no projections that can be damaged during assembly. However, cutting brush seal segments at the ends of the segments inconsistent with the bristle orientation angle, i.e., the cant angle, results in the loss of an area of the bristles. For example, where a brush seal is employed on a fixed component for sealing about a rotating shaft, the bristles of the brush seal are attached to the seal segments along the outer diameter and project radially inwardly at the cant angle. With the ends of the seal segments cut along radii, there are areas at the juncture of the seal segments where no “canted” bristles are present. That is, with the bristles canted, for example, at a 45° angle, and the end segments lying along radii, there is a triangular area on one end of one segment in which bristles do not project. However, in accordance with the present invention, the bristles are backed by a support plate in the form of a labyrinth tooth profile. Thus, the labyrinth tooth extends the full 360° about the seal, serving as a back-up seal in the event of bristle damage and serving as the primary seal in those areas where the bristles are absent by design. [0009] [0010] This particular design is useful as a retrofit seal with conventional labyrinth seals or may be used as a stand-alone seal. It is significant in that by cutting the end surfaces of the segments in a radial direction, the individual segments are free to move radially independently of one another. This is particularly important when the brush seals are retrofit to labyrinth seal segments that are spring-backed or held in place by pressure forces and therefore free to move radially during severe rotor/seal interferences. [0010] [0011] In a preferred embodiment according to the present invention, there is provided an annular brush seal for disposition between a rotatable component having an axis of rotation and another component about the axis, comprising a plurality of arcuate segments for forming an annulus about and lying in a plane normal to the axis and between the components, each segment including an arcuate array of discrete, generally linearly extending bristles secured to the segment and extending therefrom at angles offset from radii of the segments, each of the segments having opposite ends along radii thereof for substantial registration with ends of adjoining segments such that, upon assembly of the segments into an annulus, the opposed ends of each pair of adjoining segments lie substantially along a radius of the annulus with the bristles extending at angles offset from radii of the segments. [0011] [0012] In a further preferred embodiment according to the present invention, there is provided a rotary machine comprising a rotatable component, a component fixed against rotation, the components lying about a common axis, a brush seal about the axis and between the components, the brush seal including a plurality of arcuate segments forming an annular ring about the axis, each segment having opposite ends having end faces along radii of the axis for substantial registration with end faces of adjoining segments, such that the opposed end faces of each pair of adjoining segments lie substantially along a radius of the ring about the axis, with each segment having an arcuate array of discrete, generally linearly extending bristles secured thereto and extending from the segment at angles offset from radii of the segments at the circumferential location of the bristles. [0012] [0013] Accordingly, it is a primary object of the present invention to provide a novel and improved brush seal and combination labyrinth-brush seal for sealing between components rotatable relative to one another and particularly for retrofitting brush seals into labyrinth seals segmented for movement radially by spring or pressure forces. [0013] BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a schematic illustration of a sealing ring segment illustrating a labyrinth seal about a rotor; [0014] [0015] FIG. 2 is a schematic illustration of a labyrinth seal between a sealing ring segment and the covers for buckets or blades of a rotating component; [0015] [0016] FIG. 3 is a schematic illustration of a turbine wheel illustrating a labyrinth seal between the wheel and a fixed component of the turbine; [0016] [0017] FIG. 4 is an end elevational view of a segmented brush seal of the prior art; [0017] [0018] FIG. 5 is an enlarged cross-sectional view thereof taken generally about on line [0018] 5-5 in FIG. 4; [0019] FIG. 6 is an enlarged fragmentary view illustrating a plurality of brush seal segments aligned to form a ring about an axis; [0019] [0020] FIG. 7 is an enlarged cross-sectional view taken generally about on line [0020] 7-7 in FIG. 6; [0021] FIG. 8 is an enlarged cross-sectional view taken generally about on line [0021] 8-8 in FIG. 6; and [0022] FIG. 9 is a schematic illustration of a combined labyrinth brush seal of the present invention between sealing ring segments and a rotor. [0022] BEST MODE FOR CARRYING OUT THE INVENTION [0023] Referring now to the drawing figures, particularly to FIG. 1, there is illustrated a portion of a rotary machine, for example, a steam turbine, having a turbine shaft [0023] 10 disposed in a turbine housing 12 and which shaft 10 is supported by conventional means, not shown, within turbine housing 12. A labyrinth seal, generally designated 14, between the rotating shaft 10 and the stationary housing 12, includes a seal ring 16 disposed about shaft 10 separating high and low pressure regions on axially opposite sides of the ring. It will be appreciated that while only one seal 16 is disclosed, typically multiple-stage labyrinth seals are provided about rotor shafts. Each seal ring 16 is formed of an annular array of a plurality of arcuate seal elements 18 having sealing faces 20 and a plurality of radially projecting, axially spaced teeth 22. The teeth are of a hi-lo design for obtaining close clearances with the radial projections or ribs 24 and the grooves 26 of the shaft 10. The labyrinth seal functions by placing a relatively large number of barriers, i.e., the teeth, to the flow of fluid from a high pressure region to a low pressure region on opposite sides of the seal, with each barrier forcing the fluid to follow a tortuous path whereby pressure drop is created. The sum of the pressure drops across the labyrinth seal is by definition the pressure difference between the high and low pressure regions on axially opposite sides thereof. These labyrinth seal ring segments are typically spring-backed and are thus free to move radially when subjected to severe rotor/seal interference. In certain designs, the springs maintain the seal ring segments 16 radially outwardly away from the rotor, for example, during startup and shutdown, with fluid pressure being supplied between the seal ring segments and the rotor housing to displace the seal ring segments radially inwardly to obtain a lesser clearance with the rotor, i.e., close the seals, after the rotor has been brought up to speed. [0024] FIG. 2 illustrates a similar arrangement of a labyrinth seal employed at the tip of the rotating blades or turbine buckets for the rotating machine. Thus, in FIG. 2, the labyrinth seal teeth [0024] 22 a lie in sealing relation to a bucket cover 30 formed on one or more turbine buckets 32. The principal of operation of the labyrinth seal at this location is similar as described above. [0025] FIG. 3 illustrates a typical honeycomb-type labyrinth seal, for example, in a gas turbine. The labyrinth seal teeth [0025] 22 b are mounted on the rotor wheel 33 and lie in radial opposition to a honeycomb structure 34 forming part of the stator. Thus, it will be appreciated that the labyrinth seal teeth may be disposed on the rotating component of the rotary machine. [0026] Referring now to FIGS. 4 and 5, a typical brush seal, generally designated [0026] 36, includes a plurality of bristles 38 extending generally in a radial direction and which bristles 38 are disposed or sandwiched between a pair of seal plates 40 and 42. The bristles are generally formed of alloy steel wire drawn to a diameter of 0.002-0.006 inches, although larger-diameter wires for use in higher pressure environments may be used. From a review of FIG. 5, it will be seen that the backing plate 42 prevents deflection of the bristles 38 under the loading from an upstream direction of the flow, while the distal ends of the bristles project from the distal edge of the plate 42 to engage the opposite component, e.g., the rotating shaft or wheel of a rotary machine. The bristles 38 are preferably welded between the plates 40 and 42. Additionally, it will be seen from a review of FIG. 4 that the bristles and plates are provided in segments about the circumference of the axis of the rotating machine. [0027] Referring to FIG. 5, the bristles project from the distal end of backing plate [0027] 42 a distance h which corresponds to the maximum deflection of the rotor in a radial direction. Consequently, the distance h must be a minimum corresponding to that maximum deflection and is dependent on the expected relative radial deflection for the specific machine and seal location. It may be on the order of 0.040 inches. Note also that the upstream plate 40 is useful for maintaining the bristles in place during seal fabrication, although plate 40 is not necessary to the seal when in use if axial space is at a premium. It will also be noted in FIG. 4 that the bristles 38 extend along paths which are misaligned with the radius of the rotary machine. Thus, the bristles extend at an angle, preferably a common angle of approximately 30-60° to accommodate radial excursions of the shaft whereby the bristles may deflect without buckling. [0028] Referring back to FIG. 4, it will be seen that the seal plates [0028] 40 and 42 form a plurality of arcuate segments about the seal. As indicated, the adjoining end surfaces of the seal segments register and engage with one another along angled end faces corresponding to the angle of the bristles. That is, the end faces of the adjoining segments are cut at complementary common angles of approximately 30-60° relative to radii of the segments to correspond to the angle of the bristles. While this affords a satisfactory seal and a continuous 360° array of bristles about the seal, a brush seal of this type cannot be accommodated in labyrinth-type seals or retrofitted in labyrinth-type seals where the labyrinth seal segments per se are movable radially inwardly and outwardly under spring or fluid pressure. [0029] In accordance with the present invention and referring to FIG. 6, the brush seal [0029] 50 includes a plurality of bristles 52 extending at the typical angle, i.e., 30-60° relative to radii of the brush seal, i.e., the bristles at each circumferential position along each segment extend at a generally common angle relative to a radius extending to the bristles at such circumferential position. However, the individual brush seal segments 54 comprised of one or both of seal plates 56 and 58 have end surfaces formed along a radii of the brush seal. That is, the end surface 60 of each segment 54 lies along a radius relative to the axis of the components being sealed. This permits the segment 54 to move radially inwardly and outwardly relative to one another as necessary for labyrinth seal segments in certain turbine applications. It will also be appreciated from a review of FIG. 8 that the bristles 52 located between the seal plates 56 and 58 are secured at common ends to the plates and to one another by a weld 62. With that construction, it will be appreciated that there will be an area adjacent the adjoining segments 54 which do not have bristles, i.e., are void of bristles. That is, the bristles at the end of one segment are cut along the radial line of the segment, while the bristles of the adjoining end segment, because of the “cant” of the bristles, project at a distance a spaced from the juncture of the segments. Stated differently, the angled bristles 52 of one segment 54 immediately adjacent one end of such segment extend from one diameter to another diameter of the segment at an acute angle a relative to the end face of the segment, the latter extending along a radius of the segment. The bristles at the end of the adjoining segment are cut along a radius of the segment and hence terminate along the radial extending end face of the adjoining segment. This leaves a generally triangular area T at the end of each segment without or void of bristles where that segment joins with an adjacent segment. [0030] However, it has been found that the provision of a backing plate in the form of a labyrinth tooth profile and which labyrinth tooth profile extends 360° about the seal provides full sealing capability about the axis. Thus, the backing plate may comprise a labyrinth tooth [0030] 67 which extends the full 360° about the axis of the components being sealed. The lack of bristles at the ends of the seal segments does not seriously compromise or degrade the sealing capability. Note also that the bristles are supported against the labyrinth tooth 66, at least to the point where the tooth is tapered as at 68. Consequently, where brush seals are retrofit to labyrinth seal segments that are either spring-backed or held in place by pressure forces, the individual segments are free to move radially independently of one another, while the many benefits of a brush seal are provided without serious sealing degradation. [0031] Referring to FIG. 9, there is illustrated an example of a brush seal according to the present invention incorporated as a retrofit or as original equipment in a labyrinth seal. Thus, the labyrinth seal segments [0031] 70 about rotary shaft R may be removed from housing 72 and one or more of the teeth of the labyrinth seal replaced with a brush seal. Thus, in the illustrated form, the centrally-located labyrinth seal tooth is removed and a groove is formed for receiving the brush seal segments 54. In the direction of flow indicated at F, the labyrinth tooth 67 formed on one of the seal plates lies on the downstream side of the bristles 52 and the entire brush seal including the segments illustrated in FIG. 6 may be welded into place. With the end faces of the brush seal segments 54 lying parallel to the end faces of the labyrinth seal segments at like circumferential positions, it will be appreciated that the combined labyrinth seal segments and brush seal segments may move radially inwardly and outwardly with the tips of the bristles engaging the rotor R substantially throughout the full 360° circumference of the rotor, with the exception of those small areas T at the ends of the seal segments where bristles do not occur. The seals at those areas are provided solely by the labyrinth tooth 67. [0032] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. [0032]
权利要求:
Claims (14) [1" id="US-20010007384-A1-CLM-00001] 1. An annular brush seal for disposition between a rotatable component having an axis of rotation and another component about said axis, comprising: a plurality of arcuate segments for forming an annulus about and lying in a plane normal to said axis and between said components, each said segment including an arcuate array of discrete, generally linearly extending bristles secured to said segment and extending therefrom at angles offset from radii of said segments; each of said segments having opposite ends along radii thereof for substantial registration with ends of adjoining segments such that, upon assembly of the segments into an annulus, the opposed ends of each pair of adjoining segments lie substantially along a radius of the annulus with the bristles extending at angles offset from radii of the segments. [2" id="US-20010007384-A1-CLM-00002] 2. A brush seal according to claim 1 wherein each segment includes a pair of arcuate elements on opposite sides of the bristles with tips of the bristles extending beyond circumferentially extending edges of said elements. [3" id="US-20010007384-A1-CLM-00003] 3. A brush seal according to claim 2 wherein portions of said bristles remote from said tips are welded to said elements. [4" id="US-20010007384-A1-CLM-00004] 4. A brush seal according to claim 2 wherein portions of said bristles remote from said tips are welded to one another and to said elements. [5" id="US-20010007384-A1-CLM-00005] 5. A brush seal according to claim 2 wherein one of said elements comprises an arcuate tooth having a tapered edge terminating between said bristle tips and another of said elements. [6" id="US-20010007384-A1-CLM-00006] 6. A brush seal according to claim 5 wherein the bristles adjacent one end of each segment extend at an acute angle relative to said one end of said segment such that a portion of said tooth at said one end is without bristles overlying said tooth position. [7" id="US-20010007384-A1-CLM-00007] 7. A brush seal according to claim 6 wherein the bristles adjacent an opposite end of said segment terminate along the radially extending end thereof such that, upon assembly of said segments into said annulus, said one end and said opposite end of adjoining segments form a generally triangular-shaped area adjacent the juncture of the segments void of bristles. [8" id="US-20010007384-A1-CLM-00008] 8. A rotary machine comprising: a rotatable component; a component fixed against rotation; said components lying about a common axis; a brush seal about said axis and between said components, said brush seal including a plurality of arcuate segments forming an annular ring about said axis, each said segment having opposite ends having end faces along radii of said axis for substantial registration with end faces of adjoining segments, such that said opposed end faces of each pair of adjoining segments lie substantially along a radius of said ring about said axis; and each segment having an arcuate array of discrete, generally linearly extending bristles secured thereto and extending from said segment at angles offset from radii of said segments at the circumferential location of the bristles. [9" id="US-20010007384-A1-CLM-00009] 9. A rotary machine according to claim 8 wherein each segment includes a pair of arcuate elements on opposite sides of the bristles with tips of the bristles extending beyond circumferentially extending edges of said elements. [10" id="US-20010007384-A1-CLM-00010] 10. A rotary machine according to claim 9 wherein portions of said bristles remote from said tips are welded to said elements. [11" id="US-20010007384-A1-CLM-00011] 11. A rotary machine according to claim 9 wherein portions of said bristles remote from said tips are welded to one another and to said elements. [12" id="US-20010007384-A1-CLM-00012] 12. A rotary machine according to claim 9 wherein one of said elements comprises an arcuate tooth having a tapered edge terminating between said bristle tips and another of said elements. [13" id="US-20010007384-A1-CLM-00013] 13. A rotary machine according to claim 12 wherein the bristles adjacent one end of each segment extend at an acute angle relative to said one end of said segment such that a portion of said tooth at said one end is without bristles overlying said tooth position. [14" id="US-20010007384-A1-CLM-00014] 14. A rotary machine according to claim 13 wherein the bristles adjacent an opposite end of said segment terminate along the radially extending end thereof such that, upon assembly of said segments into said annulus, said one end and said opposite end of adjoining segments form a generally triangular-shaped area adjacent the juncture of the segments void of bristles.
类似技术:
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同族专利:
公开号 | 公开日 US6257586B1|2001-07-10| EP0816725A1|1998-01-07| US5749584A|1998-05-12| US6435513B2|2002-08-20| CA2205846A1|1997-12-28|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题 US6571470B1|2001-12-06|2003-06-03|General Electric Company|Method of retrofitting seals in a gas turbine| EP1387043A2|2002-07-29|2004-02-04|General Electric Company|Sealing for steam turbine diaphragm and methods of retrofitting| EP1387039A2|2002-07-30|2004-02-04|General Electric Company|Sealing of nozzle slashfaces in a steam turbine| US6821086B1|2003-06-03|2004-11-23|General Electric Company|Turbomachine seal assembly and method therefor| US6854736B2|2003-03-26|2005-02-15|Siemens Westinghouse Power Corporation|Seal assembly for a rotary machine| EP1387044A3|2002-07-30|2005-10-26|General Electric Company|Endface gap sealing of steam turbine bucket tip static seal segments and retrofitting thereof| EP1614862A1|2004-07-07|2006-01-11|Hitachi, Ltd.|Gas turbine and gas turbine cooling and sealing method| US20070114727A1|2005-11-21|2007-05-24|General Electric Company|Seal member, assembly and method| US20130234397A1|2012-03-08|2013-09-12|Mitsubishi Heavy Industries, Ltd.|Shaft sealing apparatus| US20140154060A1|2012-12-05|2014-06-05|General Electric Company|Turbomachine seal assembly and method of sealing a rotor region of a turbomachine| CN103969687A|2014-05-19|2014-08-06|国家电网公司|Steam turbine generator unit steam seal rub-impact on-line monitoring device| US10854826B2|2014-10-08|2020-12-01|Universal Display Corporation|Organic electroluminescent compounds, compositions and devices|US768593A|1903-03-24|1904-08-30|Gen Electric|Turbine-generator.| US779785A|1903-12-24|1905-01-10|Gen Electric|Packing for elastic-fluid turbines.| US910472A|1907-06-24|1909-01-19|Gen Electric|Elastic-fluid turbine.| US957887A|1908-09-28|1910-05-17|Gen Electric|Packing for elastic-fluid-turbine shafts.| US980282A|1909-07-26|1911-01-03|Gen Electric|Leakage-reducing device for steam-turbines.| US1352277A|1919-01-09|1920-09-07|Gen Electric|Elastic-fluid turbine| US1352278A|1920-03-03|1920-09-07|Gen Electric|Elastic-fluid turbine| US1505647A|1920-11-05|1924-08-19|Gen Electric|Packing for elastic-fluid turbines and the like| US1594838A|1921-08-29|1926-08-03|Kegresse Adolphe|Dust cap| US1505924A|1922-05-19|1924-08-19|Gen Electric|Shaft packing for elastic-fluid turbines and the like| US1536014A|1923-03-23|1925-04-28|Gen Electric|Packing for elastic-fluid turbines and the like| US1689735A|1923-10-05|1928-10-30|Losel Franz|Labyrinth gland construction| US1651855A|1924-06-24|1927-12-06|Gen Electric|Elastic-fluid turbine| US1670071A|1924-09-29|1928-05-15|Gen Electric|Shaft packing| US1857961A|1927-12-15|1932-05-10|Westinghouse Electric & Mfg Co|Bi-metal packing| US1895930A|1931-08-27|1933-01-31|Gen Electric|Shaft packing| US2242673A|1938-10-01|1941-05-20|Westinghouse Electric & Mfg Co|Turbine gland| US2336323A|1942-03-12|1943-12-07|Gen Electric|Sealing arrangement for elastic fluid turbines and the like| US2543615A|1947-04-24|1951-02-27|Clark Bros Co Inc|Gas seal for rotating shafts| US2600991A|1949-06-14|1952-06-17|Gen Electric|Labyrinth seal arrangement| US2709338A|1953-01-16|1955-05-31|Rolls Royce|Double-walled ducting for conveying hot gas with means to interconnect the walls| GB1010338A|1962-09-11|1965-11-17|Lucas Industries Ltd|Means for supporting the downstream end of a combustion chamber in a gas turbine engine| GB1103479A|1966-11-24|1968-02-14|Rolls Royce|Fluid seal device| US3759038A|1971-12-09|1973-09-18|Westinghouse Electric Corp|Self aligning combustor and transition structure for a gas turbine| IT1063035B|1975-05-09|1985-02-11|Maschf Augsburg Nuernberg Ag|APPARATUS FOR REALIZING THE PROCEDURE TO ELEVATE THE DYNAMIC POWER LIMIT OF STEAM OR GAS TURBINES OR COMPRESSORS| US4195476A|1978-04-27|1980-04-01|General Motors Corporation|Combustor construction| US4202554A|1978-05-17|1980-05-13|Rolls-Royce Limited|Brush seals| DE2938484C2|1979-09-22|1982-06-16|Fa. Carl Freudenberg, 6940 Weinheim|Sealing ring| GB2070700B|1980-03-01|1983-10-05|Rolls Royce|Gas turbine seals| GB2076935B|1980-05-31|1984-07-25|Rolls Royce|Seals| US4422288A|1981-03-02|1983-12-27|General Electric Company|Aft mounting system for combustion transition duct members| FR2517013B1|1981-11-21|1987-02-27|Crane Packing Ltd|SEALING| GB2254378B|1981-12-30|1993-03-31|Rolls Royce|Gas turbine engine ring shroud ring mounting| DE3215334C1|1982-04-24|1983-06-09|Dr. Johannes Heidenhain Gmbh, 8225 Traunreut|Encapsulated measuring device| ZA834537B|1982-06-30|1984-06-27|Skf Uk Ltd|Seals for bearings| US4567730A|1983-10-03|1986-02-04|General Electric Company|Shielded combustor| DE3514382C1|1985-04-20|1986-06-12|Motoren Turbinen Union|Brush seal| DE3606284C2|1985-07-31|1987-05-14|Mtu Muenchen Gmbh|| DE3606283C2|1985-07-31|1987-05-14|Mtu Muenchen Gmbh|| GB2191825B|1986-06-18|1989-12-13|Rolls Royce Plc|Means for retaining a brush seal in a housing| GB2198195B|1986-12-06|1990-05-16|Rolls Royce Plc|Brush seal| GB8712681D0|1987-05-29|1987-07-01|Cross Mfg Co 1938 Ltd|Brush seals| GB2212228B|1987-11-13|1991-08-07|Rolls Royce Plc|Enhanced performance brush seals| US4785623A|1987-12-09|1988-11-22|United Technologies Corporation|Combustor seal and support| FR2624953B1|1987-12-16|1990-04-20|Snecma|COMBUSTION CHAMBER FOR TURBOMACHINES HAVING A DOUBLE WALL CONVERGENT| DE3812533A1|1988-04-15|1989-10-26|Josef Seelen|SEAL FOR BLOW TUBE OR SHAFT| DE3828363C2|1988-08-20|1992-02-27|Mtu Muenchen Gmbh|| US5002288A|1988-10-13|1991-03-26|General Electric Company|Positive variable clearance labyrinth seal| US5029876A|1988-12-14|1991-07-09|General Electric Company|Labyrinth seal system| US4989886A|1988-12-30|1991-02-05|Textron Inc.|Braided filamentary sealing element| US5026075A|1989-02-16|1991-06-25|Westinghouse Electric Corp.|Radial seal| GB8907695D0|1989-04-05|1989-05-17|Cross Mfg Co|Seals| US5029875A|1989-07-07|1991-07-09|Textron Inc.|Fluid seal structure| JPH03209068A|1990-01-10|1991-09-12|Hitachi Ltd|Brush form seal| US4989869A|1990-03-28|1991-02-05|Lamar Lackey|Golf Tee| GB9008917D0|1990-04-20|1990-06-20|Cross Mfg Co|Brush seals| US5066025A|1990-06-18|1991-11-19|Hanrahan Paul R|Brush seal assembly| US5074748A|1990-07-30|1991-12-24|General Electric Company|Seal assembly for segmented turbine engine structures| GB9020317D0|1990-09-18|1990-10-31|Cross Mfg Co|Sealing devices| US5106104A|1990-10-11|1992-04-21|General Electric Company|Constant pressure drop multiple stage brush seal| US5076590A|1990-11-26|1991-12-31|The United States Of America, As Represented By The Administrator Of The National Aeronautics And Space Administration|High temperature, flexible pressure-actuated, brush seal| GB2250789B|1990-12-12|1994-03-30|Rolls Royce Plc|Brush seal arrangement| GB2250790B|1990-12-12|1994-04-27|Rolls Royce Plc|Brush seal| GB9103459D0|1991-02-19|1991-04-03|Cross Mfg Co|Brush seal assembly| US5176389A|1991-02-21|1993-01-05|United Technologies|Segmented brush seal| US5110033A|1991-02-21|1992-05-05|United Technologies Corporation|Segmented brush seal| US5374068A|1991-05-07|1994-12-20|General Electric Co.|Method for providing uniform radial clearance of labyrinth seals between rotating and stationary components| US5114159A|1991-08-05|1992-05-19|United Technologies Corporation|Brush seal and damper| US5181728A|1991-09-23|1993-01-26|General Electric Company|Trenched brush seal| US5201530A|1991-10-18|1993-04-13|United Technologies Corporation|Multi-layered brush seal| FR2690493B1|1992-04-23|1996-10-25|Snecma|BRUSHED ANNULAR JOINT.| US5318309A|1992-05-11|1994-06-07|General Electric Company|Brush seal| US5400586A|1992-07-28|1995-03-28|General Electric Co.|Self-accommodating brush seal for gas turbine combustor| US5335920A|1992-08-20|1994-08-09|General Electric Company|Brush seal| US5474306A|1992-11-19|1995-12-12|General Electric Co.|Woven seal and hybrid cloth-brush seals for turbine applications| US5401036A|1993-03-22|1995-03-28|Eg & G Sealol, Inc.|Brush seal device having a recessed back plate| US5351971A|1993-05-21|1994-10-04|Eg&G Sealol, Inc.|Brush seal device having a floating backplate| GB9317083D0|1993-08-17|1993-09-29|Rolls Royce Plc|A brush seal| US5547340A|1994-03-23|1996-08-20|Imo Industries, Inc.|Spillstrip design for elastic fluid turbines| US5524340A|1994-09-13|1996-06-11|General Electric Co.|Method for modifying a turbine diaphragm for use with a reduced rotor lan diameter| US5597167A|1994-09-28|1997-01-28|United Technologies Corporation|Brush seal with fool proofing and anti-rotation tab| US5509780A|1995-03-08|1996-04-23|General Electric Co.|Apparatus and method for providing uniform radial clearance of seals between rotating and stationary components| GB2301635B|1995-04-12|1998-09-16|Gec Alsthom Ltd|Shaft seal arrangement| US5599026A|1995-09-06|1997-02-04|Innovative Technology, L.L.C.|Turbine seal with sealing strip and rubbing strip| US5630590A|1996-03-26|1997-05-20|United Technologies Corporation|Method and apparatus for improving the airsealing effectiveness in a turbine engine|US6131911A|1992-11-19|2000-10-17|General Electric Co.|Brush seals and combined labyrinth and brush seals for rotary machines| US5961279A|1996-05-31|1999-10-05|Atlantic Richfield Company|Turbine power plant having minimal-contact brush seal augmented labyrinth seal| US6318728B1|1997-07-11|2001-11-20|Demag Delaval Turbomachinery Corporation|Brush-seal designs for elastic fluid turbines| US6027121A|1997-10-23|2000-02-22|General Electric Co.|Combined brush/labyrinth seal for rotary machines| US6079945A|1997-11-10|2000-06-27|Geneal Electric Company|Brush seal for high-pressure rotor applications| US6045134A|1998-02-04|2000-04-04|General Electric Co.|Combined labyrinth and brush seals for rotary machines| DE69922567T2|1998-04-01|2005-12-08|Mitsubishi Heavy Industries, Ltd.|Sealing arrangement for a gas turbine| US6220814B1|1998-07-16|2001-04-24|Siemens Westinghouse Power Corporation|Turbine interstage sealing arrangement| US6168162B1|1998-08-05|2001-01-02|General Electric Co.|Self-centering brush seal| US6105966A|1998-08-10|2000-08-22|General Electric Company|Brush seal segment| US6250640B1|1998-08-17|2001-06-26|General Electric Co.|Brush seals for steam turbine applications| US6030175A|1998-09-23|2000-02-29|General Electric Company|Hybrid seal and rotary machine containing such hybrid seal| US6116608A|1998-11-12|2000-09-12|General Electric Co.|Apparatus for guiding solid particles through a brush seal in a turbine| US6250641B1|1998-11-25|2001-06-26|General Electric Co.|Positive biased packing ring brush seal combination| US6170831B1|1998-12-23|2001-01-09|United Technologies Corporation|Axial brush seal for gas turbine engines| US6168377B1|1999-01-27|2001-01-02|General Electric Co.|Method and apparatus for eliminating thermal bowing of steam turbine rotors| JP4337965B2|1999-02-09|2009-09-30|ゼネラル・エレクトリック・カンパニイ|Labyrinth and brush combination seal for rotating machinery| US6286211B1|1999-03-24|2001-09-11|General Electric Company|Method for making a brush-tooth seal| US6139019A|1999-03-24|2000-10-31|General Electric Company|Seal assembly and rotary machine containing such seal| BR0105575B1|2000-04-06|2010-06-15||set of retractable packing segments for an apparatus that extracts work from the expansion of a gaseous working fluid.| US7032903B1|1999-04-06|2006-04-25|Turbocare, Inc.|Brush-seal designs for turbines and similar rotary apparatus| US6226975B1|1999-09-14|2001-05-08|Steven G. Ingistov|Turbine power plant having a floating brush seal| US6261057B1|1999-10-04|2001-07-17|General Electric Company|Arrangement and method for accurately radially locating a turbine brush seal| US6308958B1|1999-10-12|2001-10-30|General Electric Company|Arrangement and method for radially positioning a turbine brush seal| US6290232B1|1999-11-16|2001-09-18|General Electric Co.|Rub-tolerant brush seal for turbine rotors and methods of installation| DE60028335T2|1999-12-27|2007-02-01|General Electric Co.|Brush seal and segment for rotary machines such as gas turbines| US6367806B1|1999-12-27|2002-04-09|General Electric Company|Seal arrangement for a rotary machine such as a turbine| US6331006B1|2000-01-25|2001-12-18|General Electric Company|Brush seal mounting in supporting groove using flat spring with bifurcated end| US6471472B1|2000-05-03|2002-10-29|Siemens Canada Limited|Turbomachine shroud fibrous tip seal| US6378873B1|2000-06-02|2002-04-30|General Electric Company|Low flow fluid film seal for hydrogen cooled generators| US6394459B1|2000-06-16|2002-05-28|General Electric Company|Multi-clearance labyrinth seal design and related process| CZ20021732A3|2000-09-20|2002-10-16|General Electric Company|Steam-type gas turbine subassembly and method for enhancing turbine performance| US6464230B1|2000-10-19|2002-10-15|General Electric Company|Flexible magnetic rubber brush seal for generators| US6502824B2|2000-12-15|2003-01-07|General Electric Company|Brush seal for a bearing cavity| US6431827B1|2000-12-21|2002-08-13|General Electric Company|Bucket tip brush seals in steam turbines and methods of installation| US6728989B2|2001-01-27|2004-05-04|Applied Materials Inc.|Labyrinth seal for bearing in brush mounting assembly for semiconductor wafer scrubber| JP4719370B2|2001-03-30|2011-07-06|イーグル・エンジニアリング・エアロスペース株式会社|Brush seal device| US6547522B2|2001-06-18|2003-04-15|General Electric Company|Spring-backed abradable seal for turbomachinery| US6550777B2|2001-06-19|2003-04-22|General Electric Company|Split packing ring segment for a brush seal insert in a rotary machine| US6589012B2|2001-09-24|2003-07-08|General Electric Company|Method and apparatus for eliminating thermal bowing using brush seals in the diaphragm packing area of steam turbines| US6634650B2|2001-11-16|2003-10-21|Applied Materials, Inc.|Rotary vacuum-chuck with water-assisted labyrinth seal| US7677847B2|2002-03-26|2010-03-16|Siemens Aktiengesellschaft|Sealing assembly for a spindle| US6669202B1|2002-06-27|2003-12-30|General Electric Co.|Multi-core brush seal assembly for rotary machines| US20040046327A1|2002-09-05|2004-03-11|Menendez Robert P.|Labyrinth/brush seal combination| US20040094900A1|2002-11-15|2004-05-20|Turnquist Norman Arnold|Brush seal for static turbine components| US6790001B2|2002-11-22|2004-09-14|General Electric Company|Brush seal arrangement for high pressure applications| US6779799B2|2002-11-27|2004-08-24|General Electric Company|Sealing apparatus for electrical generator ventilation system| US6877956B2|2002-12-23|2005-04-12|General Electric Company|Methods and apparatus for integral radial leakage seal| US6969231B2|2002-12-31|2005-11-29|General Electric Company|Rotary machine sealing assembly| GB2410533B|2004-01-28|2006-02-08|Rolls Royce Plc|Sealing arrangement| US20050172438A1|2004-01-29|2005-08-11|Applied Materials, Inc.|Methods and apparatus for installing a scrubber brush on a mandrel| US20080284107A1|2004-05-04|2008-11-20|Flaherty Andrew L|Ceramic Brush Seals| US20060088409A1|2004-10-21|2006-04-27|General Electric Company|Grouped reaction nozzle tip shrouds with integrated seals| US7596395B2|2004-10-21|2009-09-29|Nokia Corporation|Depressible hinge and mobile stations using same| US7194809B2|2005-04-18|2007-03-27|Patents Holding Company|Quick release blade and knife| EP1734230A1|2005-06-13|2006-12-20|Siemens Aktiengesellschaft|Turbomachine| US7604241B2|2005-09-22|2009-10-20|General Electric Company|Seals for turbines and turbo machinery| US8407846B2|2006-03-07|2013-04-02|Applied Materials, Inc.|Scrubber brush with sleeve and brush mandrel for use with the scrubber brush| US20100143102A1|2008-02-18|2010-06-10|General Electric Company|Compliant plate seal with self-correcting behavior| US8382119B2|2006-08-15|2013-02-26|General Electric Company|Compliant plate seals for turbomachinery| US7419164B2|2006-08-15|2008-09-02|General Electric Company|Compliant plate seals for turbomachinery| EP1895107A1|2006-08-29|2008-03-05|ABB Turbo Systems AG|Exhaust gas turbine with segmented shroud ring| US7703774B2|2006-09-12|2010-04-27|General Electric Company|Shaft seal using shingle members| US20080107525A1|2006-11-02|2008-05-08|General Electric Company|Shaft seal formed of tapered compliant plate members| US8540479B2|2007-01-11|2013-09-24|General Electric Company|Active retractable seal for turbo machinery and related method| US7976026B2|2007-04-30|2011-07-12|General Electric Company|Methods and apparatus to facilitate sealing in rotary machines| US20110189000A1|2007-05-01|2011-08-04|General Electric Company|System for regulating a cooling fluid within a turbomachine| US20080309019A1|2007-06-13|2008-12-18|General Electric Company|Sealing assembly for rotary machines| US8256575B2|2007-08-22|2012-09-04|General Electric Company|Methods and systems for sealing rotating machines| US7909335B2|2008-02-04|2011-03-22|General Electric Company|Retractable compliant plate seals| US8205333B2|2008-03-06|2012-06-26|General Electric Company|Method and system for fabricating a seal ring| US8262348B2|2008-04-08|2012-09-11|Siemens Energy, Inc.|Turbine blade tip gap reduction system| US20090304493A1|2008-06-09|2009-12-10|General Electric Company|Axially oriented shingle face seal for turbine rotor and related method| US7932633B2|2008-10-22|2011-04-26|General Electric Company|Apparatus for transferring energy using power electronics and machine inductance and method of manufacturing same| US8080973B2|2008-10-22|2011-12-20|General Electric Company|Apparatus for energy transfer using converter and method of manufacturing same| US8142141B2|2009-03-23|2012-03-27|General Electric Company|Apparatus for turbine engine cooling air management| US8277172B2|2009-03-23|2012-10-02|General Electric Company|Apparatus for turbine engine cooling air management| US8505923B2|2009-08-31|2013-08-13|Sealeze, A Unit of Jason, Inc.|Brush seal with stress and deflection accommodating membrane| US8317459B2|2009-09-17|2012-11-27|General Electric Company|Systems, methods, and apparatus for providing a magnetic seal| US20110070072A1|2009-09-23|2011-03-24|General Electric Company|Rotary machine tip clearance control mechanism| US8043012B2|2009-09-30|2011-10-25|General Electric Company|Seal arrangement and a brush seal for a wind turbine| US8561997B2|2010-01-05|2013-10-22|General Electric Company|Adverse pressure gradient seal mechanism| GB2480680B|2010-05-28|2012-10-03|Alstom Technology Ltd|Labyrinth seal| US8434766B2|2010-08-18|2013-05-07|General Electric Company|Turbine engine seals| US8459653B2|2010-11-05|2013-06-11|General Electric Company|Seal assembly segment joints| US9290097B2|2010-11-05|2016-03-22|Robert Louis Steigerwald|Apparatus for transferring energy using onboard power electronics with high-frequency transformer isolation and method of manufacturing same| US20120251290A1|2011-03-31|2012-10-04|General Electric Company|Aspirating face seal, and a related method thereof| US20130075976A1|2011-09-22|2013-03-28|Todd A. Davis|Compliant mounting of an axial face seal assembly| US20130170979A1|2012-01-04|2013-07-04|General Electric Company|Double ended brush seal assembly for a compressor| US9151174B2|2012-03-09|2015-10-06|General Electric Company|Sealing assembly for use in a rotary machine and methods for assembling a rotary machine| ES2547340T3|2012-08-10|2015-10-05|MTU Aero Engines AG|Gas turbine grade| US20140205440A1|2013-01-18|2014-07-24|General Electric Company|Compliant plate seals for rotary machines| DE102013219832B3|2013-09-30|2015-03-12|MTU Aero Engines AG|Brush seal for a turbo machine| CN104074558B|2014-05-23|2016-01-20|浙江大学|A kind of rotary brush labyrinth casing| US9963991B2|2014-10-01|2018-05-08|United Technologies Corporation|Brush seal plate| US9896955B2|2015-04-13|2018-02-20|United Technologies Corporation|Static axial brush seal with dual bristle packs| US9945295B2|2015-06-01|2018-04-17|United Technologies Corporation|Composite piston ring seal for axially and circumferentially translating ducts| US9976420B2|2015-07-23|2018-05-22|General Electric Company|Aspirating seal assembly and method of assembling| KR101695125B1|2016-01-11|2017-01-10|두산중공업 주식회사|Structure for a multi-stage sealing of a turbine| US10557359B2|2016-11-03|2020-02-11|United Technologies Corporation|Seal assembly| US11028717B2|2017-06-26|2021-06-08|Raytheon Technologies Corporation|Bearing assembly for gas turbine engines| RU190835U1|2019-02-07|2019-07-15|Сергей Владимирович Ушинин|CELLULAR PRIVAL SEAL OF STEAM TURBINE|
法律状态:
2003-03-04| CC| Certificate of correction| 2006-01-03| FPAY| Fee payment|Year of fee payment: 4 | 2010-03-29| REMI| Maintenance fee reminder mailed| 2010-08-20| LAPS| Lapse for failure to pay maintenance fees| 2010-09-20| STCH| Information on status: patent discontinuation|Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 | 2010-10-12| FP| Lapsed due to failure to pay maintenance fee|Effective date: 20100820 |
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申请号 | 申请日 | 专利标题 US97873192A| true| 1992-11-19|1992-11-19|| US08/342,011|US5474306A|1992-11-19|1994-11-16|Woven seal and hybrid cloth-brush seals for turbine applications| US08/438,228|US6010132A|1992-11-19|1995-05-09|Hybrid labyrinth and cloth-brush seals for turbine applications| US67266596A| true| 1996-06-28|1996-06-28|| US08/719,667|US5749584A|1992-11-19|1996-09-25|Combined brush seal and labyrinth seal segment for rotary machines| US08/839,737|US6257586B1|1992-11-19|1997-04-15|Combined brush seal and labyrinth seal segment for rotary machines| US09/791,881|US6435513B2|1992-11-19|2001-02-26|Combined brush seal and labyrinth seal segment for rotary machines|US09/791,881| US6435513B2|1992-11-19|2001-02-26|Combined brush seal and labyrinth seal segment for rotary machines| 相关专利
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