US3592557A

US3592557A - Device for axially fixedly and radially displaceably mounting turbine casing parts

Info

Publication number: US3592557A
Application number: US881443A
Authority: US
Inventors: Horst Haas; Axel Remberg
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1968-12-03
Filing date: 1969-12-02
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13
Also published as: CH499012A; BE742579A

Abstract

Device for mounting the inner casing shell of a turbomachine of multishell construction so that it is axially fixed and radially displaceable and is centered with respect to the outer casing of the turbomachine includes an annular collar located on an annular shoulder formed at the inner periphery of the outer casing for holding the inner shell radially displaceably centered and steamtight, a ring member slidable over the outer periphery of the inner shell from one side of the annular collar facing the steam exhaust side of the turbomachine so as to axially fix the annular collar against displacement by steam pressure from the other side of the annular collar which faces the steam inlet side of the turbomachine, the ring member being anchored to the outer casing, the inner periphery of the outer casing being formed with an annular groove axially adjacent the one side of the annular collar, a closed holder ring having a plurality of axially extending divisions therein and comprising a plurality of ring parts radially insertable in the annular groove and formlockingly assemblable into the closed holder ring so that a face area thereof abuts the annular collar and fixes the inner shell against axial displacement, and a support ring at least partly overlapping the inner periphery of the holder ring for fixing the latter against radial displacement.

Description

United States Patent [72] Inventors Horst Hill; 773,430 4/1957 Great Britain 415/136 M Mulhdnbkuhr' Primary Examiner Henry F. Raduazo [21] A I No I Attorneys-CurtM. Avery, Arthur E, Wilt'ond, Herbert L. [22] Dec: Lerner and Daniel J. Tick I [45] Patented July 13, 197! [73] Assignee Siemens Aktlengeselbchalt Berlin, Germany [32] Priority Dec. 3, 1968 ABSTRACT: Device for mounting the inner casing shell of a [33] Germany turbomachine of multishell construction so that it is axially [31] P l8 l2 49ll.l8 fixed and radially displaceable and is centered with respect to the outer casing of the turbomachine includes an annular collar located on an annular shoulder formed at the inner DEVICE FOR AXIALLY "XEBLY AND RAmAl-LY periphery of the outer casing for holding the inner shell radigl lg's MQUNTING TURBINE CASING ally displaceably centered and steamtight, a ring member slidable over the outer periphery of the inner shell from one 7 CMIMJ DNWiIII a side of the annular collar facing the steam exhaust side of the 52 us. Cl 415/136, "lmmachine as axially the annular 415/108 placement by steam pressure from the other side of the annu- (511 Int. Cl. l. Fold 25/26 which faces the steam inlet side mrbomachine- 0 n M u 4 I 5 36 the ring member being anchored to the outer casing, the inner 134, 135 I3 108 periphery of the outer casing being formed with an annular groove axially adjacent the one side of the annular collar, :1 [56] Reference; Cited closed holder ring having a plurality of axially extending divin- ATES PATENTS sions tlltsre in :nd corriprising a plugaflity of rizg plarts radially inserta e m t e annu ar groove an ormoc mg y assem af ii hle into the closed holder ring so that a face area thereof abuts 3498727 3H9, r 5,136 the annular collar and fixes the inner shell against axial dise a placement, and a support ring at least partly overlapping the FOREIGN PATENTS inner periphery of the holder ring for fixing the latter against 222,283 /1924 Great Britain 415/136 radial displacement.

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DEVICE FOR AXIALLY FIXEDLY AND RADIALLY DISPLACEABLY MOUNTING TURBINE CASING PARTS Our invention relates to device for axially fixedly and radially displaceably mounting turbine casing parts. More particularly, our invention relates to such device for centering the inner casing shell (interior casing, guide vane carrier) with respect to the exterior casing in turbomachines of the mult ishell type of construction, preferably axial steam turbines with a pot-shaped casing which includes an interior shell divided in axial plane and an exterior casing, the interior shell being held radially displaceably centered and steamtightly by an annular collar located on an annular shoulder formed at the inner periphery of the exterior casing, the annular collar being axially fixed against steam pressure exerted at the side of the annular collar, namely at the steam inlet side of the turbine, by ring members slid over the outer periphery of the interior shell from the other side of the annular collar, namely the steam exhaust side of the turbine, and anchored to the exterior casing.

Such a device is known from the German Pat. No. DB? l,l40,947 wherein the ring members holding the interior shell against an annular shoulder formed at the inner periphery of the pot-shaped exterior casing are provided with a bayonet ring; such bayonet ring is slid, in a direction from the steam exhaust end of the interior shell, over the latter until it reaches an outer toothed collar located behind a toothed collar at the inner periphery of the exterior casing and then, by being suitably rotated, engages the teeth of the toothed collar on the exterior casing and is thereby fixed against displacement in axial direction.

It is an object of our invention to provide device for axially fixedly and radially displaceably mounting turbine casing parts which is of improved and relatively simplified construction to avoid any necessity for rotating ring members so as to effect a threadlike or bayonetlike meshing of ring members with projections from the exterior casing.

With the foregoing and other objects in view, we provide in accordance with our invention, device for mounting the inner casing shell of a turbomachine of multishell construction so that it is axially fixed and radially displaceable and is centered with respect to the outer casing of the turbomachine comprising an annular collar located on an annular shoulder formed at the inner periphery of the outer casing for holding the inner shell radially displaceably centered and steamtight, a ring member slideable over the outer periphery of the inner shell from one side of the annular collar facing the steam exhaust side of the turbomachine so as to axially fix the annular collar against displacement by steam pressure from the other side of the annular collar which faces the steam inlet side of the turbomachine, the ring member being anchored to the outer casing, the inner periphery of the outer casing being formed with an annular groove axially adjacent the one side of the annular collar, a closed holder ring having a plurality of axially extending divisions therein and comprising a plurality of ring parts radially insertable in the annular groove and form-lockingly assemblable into the closed holder ring so that a face area thereof abuts the annular collar and fixes the inner shell against axial displacement, and a support ring at least partly overlapping the inner periphery of the holder ring for fixing the latter against radial displacement.

The advantages attainable by the invention are primarily that a convenient form-locking insertability of the holder ring is provided whereby the holder ring absorbs all forces in axial direction and the support ring is virtually free of axial forces so that it is only required to protect the holder ring from falling out of its position. Because of this insertability of the holder ring, a simple fastening element can be used as support ring.

In accordance with another feature of our invention, the holder ring is formed of four ring parts whose joints extend in planes parallel to an axial plane of the turbomachine, pairs of the ring parts being of similar construction. Thus, one of the pairs of holder ring parts is initially insertable in the annular groove. and the other pair is then insertable in radial direction i.e. in the same direction in which the joints of the rings extend. Thereby the number of holder ring parts is kept at a minimum.

In accordance with a further feature of our invention, the inner shell has an axial joint, and one of the pairs of holder ring parts covers and is disposed symmetrically opposite the axial joint of the inner shell overlapping substantially twothirds of the periphery of the inner shell.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in device for axially fixedly and radially displaceably mounting turbine casing parts, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. I is a longitudinal sectional view ofa high-pressure turbine of axial superpressure construction type and with multishell casing structure having the mounting and centering device of our invention;

FIG. 2 is a cross-sectional view of FIG. I taken along the line Il-II, showing the inner casing annular collar and the joint flange of the outer casing;

FIG. 3a is a fragmentary muchenlarged view of FIG. 1 showing one of the centering pin devices;

FIG. 3b is a sectional view of FIG. 3a taken along the line IIlb-lllb in the direction of the arrows;

FIG. 3c is a cross-sectional view of FIG. 3b taken along the line lIIc-lllc in the direction of the arrows; and

FIG. SM is a schematic view illustrating the principle of the centering pin device in a radial centering plane perpendicular to the axis of the turbine shaft, wherein centering pins are pro vided above and below (as viewed in FIGS. I and 2) as well as left and right of the turbine shaft.

In the figures, like members and features are identified by the same reference numerals.

Referring now to the drawings, and particularly to FIGS. I and 2 thereof, there is shown the device of our invention for axially fixedly and radially displaceably mounting and centering an inner casing shell 1, having shell halves la and 1b, with respect to an outer casing 2 of an axial reaction turbine. The turbine has a multishell type of construction with a tank or potlike casing, a casing part 2a of the outer tank being at the steam delivery end 3 of the turbine, and a casing part 2b of the outer tank being at the steam exhaust end 4 of the turbine. The inner shell I is formed as a combined guide vane carrier inner casing with the steam delivery end 3 and the steam exhaust end 4 of the turbine, a stepped space or blading channel 6 being located between the turbine shaft 5 and the inner casing shell 1. Runner blade rings 7 are fastened in axial succession to the shaft 5, and guide vane rings 8 are fastened in axial succession to the inner periphery of the inner casing shell I. The latter has a sealing shell 9 at the steam delivery end 3 that is provided at the inner periphery thereof with an axial labyrinth seal Ill and is additionally formed with pressure-relieving channels I l. interconnecting the blading channel 6 with a space I2 located between the inner casing shell I and the outer casing part 2a so that the space I2 is subjected to a pressure intermediate the delivered steam pressure at 3 and the exhaust steam pressure at 4. Shaft seals I3 and I4 in the form of sealing shells are provided at the ends of the outer casing 2 located respectively, at the steam delivery end 3 and the steam exhaust end 4 of the turbine. The shaft seals I3 and 14 are provided at the inner periphery thereof with axial labyrinth seals I5. Sealing covers 16 and I7 likewise serving as shaft seals are sealingly fastened to suitable flanges on the ends of the outer casing 2 located at the steam delivery and exhaust ends 3 and 4, respectively, of the turbine. Also provided are hereinafter further described radial pins or bolts 18, received in eccentric bushings and having slide blocks or rings [8a at the free ends thereof, for adjustably mounting the inner shell 1 in a radial plane 19 or the sealing shells l3 and 14 in radial planes 20 and 21, respectively, so as to be axially and radially centrally heat displaceable. Elastic, U-shaped sealing rings 22 are disposed between the sealing shells l3 and 14, on the one hand, and adjacent engagement shoulders 23 formed in the outer housing casing 2. Exhaust steam is discharged through an exhaust pipe 24 which can be connected to a succeeding turbine stage or an intermediate superheater. The outer casing parts 20 and 2b are connected at radially extending flanged joint 25 secured by flange bolts diagrammatically represented by the dot-dash lines 26, the flanged joint 25 being also provided with a U-shaped elastic sealing ring 27. The steam flows in the direction of the arrows 28 from fresh steam inlets (not shown), connected steamtightly and heat transferably to the inner shell 1, into the inflow chamber or steam chest 29 wherefrom it travels through the blading channel 6 expending power and dropping in pressure until it reaches the exhaust chamber 30 wherefrom it is discharged through the exhaust pipe 24.

In the vicinity of the cutting plane NJ], the inner shell 1, which, as shown in FIG. 2, is formed with an axial joint 0 at which nonillustrated flanges are clamped together by means of flange bolts 31, is held radially displaceably centered and steamtight with an annular collar 32 (FIG. 1) at an annular shoulder 33 formed on the inner periphery of the outer casing 2. By means of ring members, which are anchored to the outer housing 2 and are slipped over the outer pe iphery of the inner shell 1 from the end thereof located adjacent the steam exhaust end 4 of the turbine, the annular collar 32 is axially fixed against displacement by the steam pressure prevalent at the steam inflow end 3 of the turbine According to our invention, axially adjacent to the side of the annular collar 32 facing toward the exhaust end 4 of the turbine there is located at the inner periphery of the outer housing 2 an annular groove 34. A holder ring 35 divided several times in axial direction is provided. Ring parts or

segments

35a, 35b, 35c and 35d (FIG. 2) which, with an inner shell 1 inserted in the outer casing 2 and its annular collar 32 abutting the annular shoulder 33, are insertable radially in the annular groove 34 and are assemblable form-lockingly into the closed holder ring 35, The holder ring 35, with the face area 36 thereof covering the annular collar 32, fixes the inner shell 1 in axial direction, and is fixed in turn, in radial direction by a support ring 37 at least partly overlapping the inner periphery thereof which prevents the ring parts 35a to 35d thereof from slipping out and prevents them from turning about due to axial forces. The support ring 37, in turn, is not stressed in axial direction by steam forces, and requires, therefore, only to be secured in axial direction by small pin screws 38 or similar fastening members. Advantageously the holder ring 35 is composed ofthe aforementioned four ring parts 35a to 35d, whose joints 39 extend in planes parallel to the axial joint 0 of the inner shell 1, pairs of the ring parts, as shown in FIG. 2, namely the ring parts 35a and 350, on the one hand, and 35b and 35d, on the other hand, having the same construction. The axial joint 0 of the inner shell l can coincide with a horizontal plane extending through the center of the shaft 5. but can also lie, however, in a vertical axial plane, as viewed in FIG. 2. As shown, the pair of ring parts 350 and 35c covering the axial joint a ofthe inner shell 1 extends over about two-thirds the periphery of the inner shell I; furthermore, the ring parts 350 to 35d are disposed symmetrically with respect to the joint a as well as to the axial plane perpendicular thereto, the assembly and manufacture being facilitated because of the similar structural components.

Advantageously, the annular collar 32 of the inner shell 1 is held by the holder ring 35 against an elastic U-shaped sealing ring 40 which is inserted in an annular groove 4| located axially adjacent the annular collar 32 at the side thereof facing the steam inflow end 3. The base of the U'shaped sealing ring 40, as shown in FIG. 1, a uts the base of the groove 4i, and the legs of the U-shaped ring 40 abuts the annular collar 32 or the groove sides 41a in the outer casing 2 which are located opposite the annular collar 32.

Centering blocks 42 (FIG. 2) are located between the annular collar 32 and the outer casing 2 and are inserted in corresponding casing pockets 43a and 43b, respectively, at the outer casing 2 and the inner shell I. The centering blocks 42 are drawn against the outer casing 2 by screw bolts 44 and are provided at the lateral sides thereof extending in axial direction with slide keys 45 on which the inner shell 1 can slide in radial direction. Correspondingly, radial gaps 46 are provided between the inner shell l and the centering blocks 42 or between the inner shell 1 and the outer casing 2. The centering blocks 42 are disposed in the form of a cross symmetrical to the axis of the shaft 5. Due to the thickness of the slide keys 45 an accurate adjustment can also be made in the plane 19(FlG. i} perpendicular to the axis of the shaft 5 with respect to the centering in that plane.

Assembly is effected relatively easily by means of the mounting and centering device of our invention. The vertical position of the shaft 5 provided with the inner shell I and the shaft seal 13 can be lowered somewhat into the outer casing part 2a when inserting the elastic sealing rings shells 23, the elastic sealing ring 40 having been previously placed in the groove 41 therefor, and the sealing blocks 42 having been previously fastened to the outer casing 2. Centering can then be effected in the planes l9, 20 and ll-Il, whereupon the

ring parts

35b and 35d of the holder ring 35 are initially inserted and, thereafter, the ring parts 35a and 35c. The support ring 37 is then inserted and axially fixed. The casing part 2b with the sealing shell 14 can thereafter be mounted.

In FIG. 3d there is illustrated the principle of radial pin cen tering in a schematic and perspective view between a generally identified inner shell 1 and a generally identified outer casing 2. The rotary axis of the turbine is identified by the reference character 1. As indicated, four suspension or centering

points

21, 22,23 and Z4 are provided per centering plane, each of the centering points being afforded a relative displacement of both

housing parts

1 and 2 with respect to one another in the peripheral direction as indicated by the doubleheaded arrows t, in the radial direction as indicated by the double-headed arrows r and in the axial direction as indicated by the double-headed arrows a. Ofthe just-mentioned arrows, the arrows t are shown respectively extended to imply that they relate to an adjustment in the peripheral direction at as sembly, which is a fixed adjustment, while the broken arrows a and r are meant to imply that a radially central heat movable relative displacement, due to dissimilar thermal expansions between the inner casing l on the one hand and the outer casing 2 on the other hand is possible in axial and radial direction during the operation of the turbine. The use of the

reference characters

19, 20, 2| is meant to bring out that the aforedescribed centering principle is applicable for the centering pin devices in the radial centering

planes

19, 20, 21 of FIG, l. Accordingly, the hereinafter following description of FIGS. 30 to 3c is applicable for all of the aforementioned centering pin devicesv As is shown in FIGS. 3a to Be in detail, the outer casing 2 is formed with a radial bore 18c wherein a cylindrical bushing 18:! formed with a flange 18c is inserted. The bushing 18d is provided with an eccentric bore 18f whose eccentricity e is clearly shown in FIG. 3c. The hollow cylindrical centering pin or bolt 18 is inserted n this eccentric bore 18f, and the lower end of the eccentric pin 18 is fitted in a sliding block or ring or an adjusting spring 18a. The sliding ring 180 is slidingly guided in the axial direction of the turbine with sliding surfaces [8b thereof extending in the axial direction of the turbine against corresponding opposing surfaces 23h of longitudinal grooves 23l formed in the inner shell 1. In order that the slide blocks or rings be prevented from slipping within the sliding surfaces l8h of the inner shell 1 when the respective centering pin device is installed, they are secured with a set screw I80 (FIG. 30) within a recess [81 formed in the inner casing I so that, as shown, adequate clearance for movement of the respective slide blocks or rings 18a in the axial direction is provided. The radial pins or bolts 18 are provided at their outer periphery with grooves 182 through which a possible wear or binding between the

parts

18 and 18d which are radially displaceable relative to one another can be suppressed. A cover 18k is tightly fastened by bolts [83 from the outside on the outer casing 2 to seal the casing bore 18c and is pressed by an annular bead 184 formed thereon against corresponding opposing surfaces formed on the outer casing 2. As shown in FIGS. 3a and 36, relative motion in the radial direction between the radial pins 18 and bushings 18d as well as between the pins I8 and the sliding blocks or rings 18a in radial direction is afforded as represented by the arrow r of FIG. 3d. Furthermore, relative motion in axial direction between the sliding blocks or rings Ida and the respective opposing surfaces I811 at the inner casing 2 is afforded in direction of the arrow :1, as shown in FIG. 34. The adjustment, i.e. the centering, of the inner shell I with respect to the outer casing 2 is effected, with the covers 18!: removed, by turning the respective bushings [M in their bore 18c. When the foregoing measures are carried out in all four centering points Z1 to 24 of a centering plane (FIG. 3d), all desired relative positions of the inner shell 1 with respect to the outer casing 2 can then be attained within the desired adjustment limits, i.e. a raising or lowering or a lateral displacement or a rotation in the peripheral direction of the inner shell 1 relative to the outer casing 2.

We claim:

I. Device for mounting the inner casing shell of a turbomachine of multishell construction so that it is axially fixed and radially displaceable and is centered with respect to the outer casing of the turbomachine comprises an annular collar located on an annular shoulder formed at the inner periphery of the outer casing for holding the inner shell radially displaceably centered and steamtight. a ring member slidable over the outer periphery of the inner shell from one side of said annular collar facing the steam exhaust side of the turbomachine so as to axially fix said annular collar against displacement by steam pressure from the other side of said annular collar which faces the steam inlet side of the turbom'achine, said ring member being anchored to the outer casing, the inner periphery of the outer casing being formed with an annular groove axially adjacent said one side of said annular collar, a closed holder ring having a plurality of axially extending divisions therein and comprising a plurality of ring parts radially insertable in said annular groove and form-lockingly assemblable into said closed holder ring so that a face area thereof abuts said annular collar and fixes the inner shell against axial displacement, and a support ring at least partly overlapping the inner periphery of said holder ring for fixing the latter against radial displacement.

2. Mounting device according to claim 1 wherein said holder ring comprises four ring parts having joints extending in planes parallel to an axial plane of the turbomachine, pairs of said ring parts being of similar structure.

3. Mounting device according to claim 2 wherein the inner casing shell has an axial joint, and one of said pairs of holder ring parts covers and is disposed symmetrically opposite the axial joint of the inner shell, said one pair of holder ring parts extending over substantially two-thirds of the periphery of the inner shell.

4. Mounting device according to claim 1 wherein an annular groove is fonned in the outer casing axially adjacent said annular collar at said other side thereof facing the stem inlet side, said annular collar being held by said holder ring against an elastic U-shaped sealing ring received in said annular groove, the base of said U-shaped sealing ring abutting the base of said groove and the legs of said U-shaped sealing ring respectively abutting said annular collar and a side of said groove located 0 posite said annular collar.

5. Mountlng evtce according to clatm I including casing pockets located between said annularcollar and the outer casing, centering blocks respectively received in said casing pockets, said holder ring simultaneously fixing said centering blocks in addition to the inner shell, against axial displacement, said centering blocks being disposed in the form of a cross symmetrical to the turbomachine axis, said centering blocks being actuable for mounting the inner shell radially centrally heat transferably and for adjusting the inner shell in respective radial planes at assembly thereof.

6. Mounting device according to claim I, including fastening means extending in axial direction for fixing said support ring to the outer casing against axial displacement, said fastening means being received in bores having axes disposed in an annularjoint between said support ring and the outer casing.

7. Mounting device according to claim 6 wherein said fastening means are set screws.

UNITED STATES PATENT OFFICE R CERTIFICATE OF CORRECTION Patent NO. 3:59 :55? Dated July 13, 1971 I v Horst Haas and Axel Remberg It: is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading, page 1, column 1 the German priority number should read P l8 l2 90.8

Signad and seaied this 23rd day of November 1971.

(SEAL) Attest:

EDWARD M F LETC HER JR Attesting Officer ROBERT GOTTSCHALK Acting Commissioner of Patents

Claims

1. Device for mounting the inner casing shell of a turbomachine of multishell construction so that it is axially fixed and radially displaceable and is centered with respect to the outer casing of the turbomachine comprises an annular collar located on an annular shoulder formed at the inner periphery of the outer casing for holding the inner shell radially displaceably centered and steamtight, a ring member slidable over the outer periphery of the inner shell from one side of said annular collar facing the steam exhaust side of the turbomachine so as to axially fix said annular collar against displacement by steam pressure from the other side of said annular collar which faces the steam inlet side of the turbomachine, said ring member being anchored to the outer casing, the inner periphery of the outer casing being formed with an annular groove axially adjacent said one side of said annular collar, a closed holder ring having a plurality of axially extending divisions therein and comprising a plurality of ring parts radially insertable in said annular groove and formlockingly assemblable into said closed holder ring so that a face area thereof abuts said annular collar and fixes the inner shell against axial displacement, and a support ring at least partly overlapping the inner periphery of said holder ring for fixing the latter against radial displacement.

4. Mounting device according to claim 1 wherein an annular groove is formed in the outer casing axially adjacent said annular collar at said other side thereof facing the stem inlet side, said annular collar being held by said holder ring against an elastic U-shaped sealing ring received in said annular groove, the base of said U-sHaped sealing ring abutting the base of said groove and the legs of said U-shaped sealing ring respectively abutting said annular collar and a side of said groove located opposite said annular collar.

5. Mounting device according to claim 1 including casing pockets located between said annular collar and the outer casing, centering blocks respectively received in said casing pockets, said holder ring simultaneously fixing said centering blocks in addition to the inner shell, against axial displacement, said centering blocks being disposed in the form of a cross symmetrical to the turbomachine axis, said centering blocks being actuable for mounting the inner shell radially centrally heat transferably and for adjusting the inner shell in respective radial planes at assembly thereof.

6. Mounting device according to claim 1, including fastening means extending in axial direction for fixing said support ring to the outer casing against axial displacement, said fastening means being received in bores having axes disposed in an annular joint between said support ring and the outer casing.