US2862687A - Axial flow turbomachine - Google Patents

Description

Dec. 2, 1958 E. AGUET EIAL AXIAL FLOW TURBOMACHINE 2 Sheets-Sheet '1 Filed Oct. 1, 1954 INVENTORS. EM/LEAGUET. FRANZScI-MEE.

BY (ii/457A;

ATTORNEK' Dec. 2, 1958 E. AGUET ETAL 8 AXIAL FLOW TURBOMACHINE Filed Oct. 1, 1954 r 2 Sheets-Sheet 2 IN V EN TORS.

EMILE AGUET A TTOANEK Fan ZSCHAEE.

AXIAL FLOW TURBOMACHlNE Emile Aguet and Franz Schaer, Winterthur, Switzerland,

assignors to Sulzer Freres, Socit Anonyme, Winterthur, Switzerland, a corporation of Switzerland The present invention relates to an axial flow turbomachine having running blades or buckets mounted on a rotor and stationary guide buckets extending between the running buckets and being adjustably mounted on the casing of the machine, an adjusting mechanism being provided for changing the position of the guide buckets.

In a conventional machine of this type, each individual guide bucket Was provided with a threaded bolt extending through the casing and screwed thereto. This screw connection was covered by a screwed-on cap. In another conventional machine provided with adjustable guide buckets, essential parts of the adjusting mechanism were mounted on the exterior of the casing; these parts were connected with the guide buckets by driving members extending through the casing.

It is an object of the present invention to provide an adjusting mechanism for guide buckets of turbomaehines in which essential parts of the adjusting mechanism are located in a special chamber provided between the casing of the turbomachine and the rotor. In the machine according to the invention, the adjusting mechanism is protected. The casing of the machine according to the invention has an exterior substantially cylindrical surface portion which is smooth, so that, for example, it is not possible for the attendants to tear their clothes; the smooth configuration of the casing facilitates cleaning. The new arrangement makes it possible to use a mechanism consisting of a greater number of individual parts, as required for machines having a great number of guide buckets, without impairing the operational reliability, for instance by fouling.

In a preferred embodiment of the invention, the chamber for housing the adjusting mechanism comprises an Outer wall formed by the turbine casing and an inner wall which is substantially cylindrical and formed by a member which serves also as a carrier for the guide buckets, the chamber being closed at its axial ends. In this way, the adjusting mechanism is protected also against influences from within, for example foreign matter which may be carried along by the operating medium of the turbomachine.

In an embodiment of the invention, the casing and the carrier for the guide buckets are connected by means of an annular rim and a corresponding groove, the connection absorbing axial thrust. The new machine retains the advantage of certain conventional designs in which the carrier for the guide buckets changes only its length at temperature variations, but cannot be bent as is sometimes the case in machines in which the carrier for the guide buckets is connected with the casing at several points or is made in one piece with the casing.

In an embodiment of the invention, an adjusting mechanism for changing the position of all guide buckets is placed in the space between the casing and the rotor. The mechanism includes adjusting shafts which are supported on the outside of the carrier for the guide buckets and which are placed substantially parallel to the axis of nited States Patent rotation of the turbomachine, cooperating bevel gear wheels being mounted on the shafts and on the guide buckets, and all shafts being rotated by a common drive.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself however and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in conjunction with the accompanying drawing, in which Fig. l is a diagrammatic longitudinal section of a. turbomachine according to the invention;

Fig. 2 is a diagrammatic longitudinal section of a turbomachine according to the invention having a modified adjusting mechanism for the guide buckets;

Fig. 3 illustrates a detail of the mechanism according to Fig. 2;

Fig. 4 is a diagrammatic longitudinal sectional view of another modification of the turbomachine according to the invention.

The same numerals designate the same parts in all figures.

Referring more particularly to the drawing, numeral 1 designates a rotor which carries running buckets 2, and which is rotatably borne in a main machine casing 3. The latter is provided with an inlet conduit 4 and an outlet conduit 5 for the medium passing through the turbomachine. A chamber 7 is formed between the rotor 1 and a substantially cylindrical portion 6 of the casing 3, the inner wall of the chamber 7 being formed by a substantially cylindrical auxiliary casing which serves as a stationary carrier 9 for the guide buckets 8. A collar 10 is provided at the right end of the carrier 9, which collar extends into a corresponding annular groove 11 provided in the casing 3. The portion 6 of the casing 3 and the carrier 9 are provided substantially in the middle of their length with fins or protuberances 12, 13, respectively. Bolts 14 and 15 are screwed into the fin 12 and extend through longitudinal holes in the fin 13.

The bolts are so arranged that at temperature variations the carrier 9 can slide along the protuberance 12. The protuberances 12 and 13 act as bearings for receiving radial pressure. The axial ends of the chamber 7 are closed by portions 16 and 17 of the machine casing, which portions also form parts of the channels for the medium flowing through the turbomachine.

An adjusting mechanism is placed in the chamber 7 which mechanism affords simultaneous adjustment of all guide buckets 8. The mechanism includes adjusting shafts 20 which are rotatably supported at 18 and 19 by the carrier 9,pairs of bevel gears 21, 22, of which only one is shown, transmitting rotation of the shafts 20 to the guide buckets 8. At the left end of each shaft 20, a spur gear wheel 23 is mounted which meshes with a toothed rim 24 provided on a ring member 25 which is composed of two halves. Teeth 26 are provided on the exterior rim of the ring 25, the teeth 26 meshing with the teeth of a bevel gear wheel 28 supported at the end of the shaft of a driving motor 27. The shaft of the motor 27 extends through a bore 29 in the casing 3. All parts of the adjusting mechanism, except the driving motor 27, are arranged in the space 7 inside of the casing of the turbomachine.

Figs. 2 and 3 illustrate a modification of the adjusting mechanism in which push rods 30 are provided in lieu of the rotating shafts 20 of the modification shown in Fig. 1. The push rods extend substantially parallel to the rotation axis of the turbomachine and are connected by means of levers 32 with the guide buckets 8. The push rods 30 are actuated individually by means of levers 31 which comprise an arcuate portion having teeth 23 meshing with teeth 24' on an annular member 25-. The latter is driven by a motor 27 in the same manner as is the ring 25 of Fig. 1.

In a-further modification of the invention which is illustrated in Fig. 4, two independent adjusting mechanisms are provided and a carrier 9 for the guide buckets 8- is supported by a portion 6 of a casing 3 substantially in the longitudinal middle of the carrier by a rim and groove connection 10, 11. One of the adjusting mechanisms affords adjustment of the guide buckets of the stages of the turbomachine at the left of the groove and rim connection 11', 10', between the casing 6- and the carrier 9' for the guide buckets. The other adjusting mechanism is arranged at the right side of the rim and groove connection 10, 1'1 and affords adjustment of the guide buckets of the stages at the right end of the rotor 1. The first adjusting mechanism, at the left side of Fig. 4, corresponds to the mechanism shown in Fig. 1, the same numerals being used for identical parts. The adjusting mechanism on the right side of Fig. 4 is fundamentally the same as the mechanism shown on the left side and the same numerals are used for designating identical parts, the numerals, however, being provided with. a.

The motor 27 in all modifications may be an electric motor, a hydraulic motor, or a pneumatic motor. Motors may be omitted and the adjusting mechanism may be actuated by hand, in which case hand wheels would be provided in lieu of the motors 27.

The length of the chamber 7 depends on the construction of the adjusting mechanism. The cross-section of the chamber may be more or less tapered in the longitudinal direction of the machine, depending on the space requirements of the adjusting mechanism which is placed in the chamber.

Whereas an axial flow compressor has been described, the invention may also be used in an axial flow turbine.

While specific embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

l. A multistage axial flow turbomachine comprising a rotor, buckets mounted on said rotor, a substantially cylindrical auxiliary casing extending over substantially the whole length of said rotor, guide buckets interposed between said first mentioned buckets and adjustably mounted on said auxiliary casing, a main casing separable from said auxiliary casing and having an oblong portion forming an envelope completely enclosing said auxiliary casing, said oblong portion being radially spaced from said auxiliary casing to form a substantially cylindrical completely closed cavity, and actuating means placed in said cavity and operatively connected with said guide buckets for simultaneously adjusting the position of said guide buckets, said auxiliary casing and said main casing being interconnected by means of an annular rim and an annular groove receiving said rim for preventing axial displacement of said auxiliary casing relatively to said main casing.

2. A multistage axial flow turbomachine comprising a rotor, buckets mounted on said rotor, a substantially cylindrical auxiliary casing extending over substantially the whole length of said rotor, guide buckets interposed between said first mentioned buckets and adjustably mounted on said auxiliary casing, a main casing separable from said auxiliary casing and having an oblong portion forming an envelope completely enclosing said auxiliary casing, said oblong portion being radially spaced from said auxiliary casing to form a substantially cylindrical completely closed cavity, and actuating means placed in said cavity and operatively connected with said guide buckets for simultaneously adjusting the position of said guide buckets, said adjusting means including a plurality of shafts disposed substantially parallel to the rotation axis of the turbomachine, gears interconnecting said shafts and said guide buckets, and means for simultaneously rotating said shafts.

3. A turbomachine according to claim 2, in which said means for simultaneously rotating said shafts include an annular member having two toothed rims, drive means including a pinion engaging one of said toothed rims, and pinions individually mounted on said shafts and engaging the other of said toothed rims.

4. A multistage axial flow turbomachine comprising a rotor, buckets mounted on said rotor, a substantially cylindrical auxiliary casing extending over substantially the whole length of said rotor, guide buckets interposed between said first mentioned buckets and adjustably mounted on said auxiliary casing, 21 main casing separable from said auxiliary casing and having an oblong portion forming an envelope completely enclosing said auxiliary casing, said oblong portion being radially spaced from said auxiliary casing to form a substantially cylindrical completely closed cavity, and actuating means placed in said cavity and operatively connected with said guide buckets for simultaneously adjusting the position of said guide buckets, said actuating means including a plurality of push rods disposed substantially parallel to the rotation axis of the turbomachine, levers interconnecting said push rods and said guide buckets, and means for simultaneously axially moving said push rods.

5. A turbomachine according to claim 4, in which said means for simultaneously axially moving said push rods include an annular member having two toothed rims, drive means including a pinion engaging one of said toothed rims, and levers individually pivotally connected with said push rods and having a curved toothed marginal portion engaged by the other of said toothed rims for swinging said levers.

References Cited in the file of this patent UNITED STATES PATENTS 2,300,766 Baumann Nov. 3, 1942 2,371,706 Planiol Mar. 20,. 1945 2,424,839 Morton July 29, 1947 2,500,070 Hagen Mar. 7, 1950 2,651,492 Feilden Sept. 8, 1953 2,671,634 Morley Mar. 9, 1954 FOREIGN PATENTS 237,490 .Germany Feb. 23, 1911 621,175 Great Britain Apr. 5, 1949 701,576 Great Britain Dec. 30, 1953

Images