US2746713A

US2746713A - Distributor vane operating apparatus for hydraulic turbines

Info

Publication number: US2746713A
Application number: US237633A
Authority: US
Inventors: Peyrin Henri; Casacci Severin Xavier
Original assignee: Neyrpic SA
Current assignee: Neyrpic SA
Priority date: 1950-08-04
Filing date: 1951-07-19
Publication date: 1956-05-22
Anticipated expiration: 1973-05-22

Description

May 22, 1956 Filed July 19, 1951 H. PEYRIN EI'AL DISTRIBUTOR VANE OPERATING APPARATUS FOR HYDRAULIC TURBINES 2 Sheets-Sheet l INVENTORS flew; Pegnw I Swarm java r l'asaza TTORA/E Y May 22, 1956 H. PEYRIN ETAL DISTRIBUTOR VANE OPERATING APPARATUS FOR HYDRAULIC TURBINES 2 Sheets-Sheet 2 Filed July 19 1951 INVENTOR. f/(nn aqrm 500!!! Jame! Q5 1 61 ,qrmmvEY United States Patent DISTRIBUTOR VANE OPERATING APPARATUS FOR HYDRAULIC TURBINES Henri Peyrin and Severin Xavier Casacci, Grenoble, France, assignors to Etablissements Neyrpic, Grenoble, France, a corporation of France Application July 19, 1951, Serial No. 237,633

Claims priority, application France August 4, 1950 3 Claims. (Cl. 253-155) The present invention relates to distributor vane operating apparatus for hydraulic turbines and particularly to servomotor apparatus and linkages connecting the servomotor apparatus to the vanes.

In order to direct the flow of water in a suitable manner through the turbine runner of a hydroelectric generating unit, a distributor is commonly located upstream from the turbine runner. This distributor is usually formed of flow directing vanes disposed between two rigid frames fastened upon sills which are mounted on the masonry or concrete foundation. to vary the angle of attack of the water against the blades of the turbine runner, there is commonly provided a first distributor having fixed blades and downstream therefrom a second distributor having movable blades. The simultaneous setting of these movable blades is usually accomplished by the rotation of a heavy disc called a shifting ring. The shifting ring rotates about the axis of the turbine and generator unit and is driven by means of one or more servomotors.

In turbine and generator units of the hydraulic type, the apparatus for positioning the movable vanes of the distributor is commonly large and complex. In conventional turbine and generator units, there is usually a considerable space available between the turbine and the generator, and it is always possible to provide sufiicient space for the apparatus for driving the shifting ring, however large and cumbersome that apparatus may be. It is not practical to use such arrangements with turbine and generator assemblies of the unitary submerged type, such as disclosed in the copending application of Jean Claude Guimbal, Serial No. 193,851, filed November 3, 1950, now Patent No. 2,634,375, issued April 7, 1953,, because of the necessity for giving to the assembly a streamlined exterior form having suitable hydraulic characteristics.

It is very desirable in the latter case to locate all the mechanism for rotating the distributor vanes within the interior of the turbine and generator assembly so as to utilize to the maximum the space existing between the generator and the turbine. This space must be provided because of the dimensional requirement for obtaining optimum hydraulic flow conditions past the generator and through the turbine, which a view to obtaining the best possible efficiency of the hydroelectric unit. This concentration of the apparatus within the unit is desirable not only in unitary submerged assemblies, but also in turbine and generator assemblies of other types.

An object of the present invention is to provide, in a turbine and generator assembly, an improved mechanism for operating the movable vanes of a distributor. A

further object is to provide such mechanism compactly located within the assembly so as to secure optimum hydraulic flow conditions.

This invention may be carried out in a turbine structure having a distributor section providing an outer casing and an inner casing about the axis of rotation by When it is desired locating the apparatus which positions the shifting ring, particularly the servomotors, within the interior of the inner distributor casing. The streamlined outer wall of the turbine and generator unit is provided with an enlarged diameter through the section where it is aligned with the distributor. The principal active part within this section of the inner casing is the main shaft, which is much smaller than the inner casing, the latter being enlarged for streamlining purposes. In accordance with the present invention, the space within this section of the inner casing is utilized as a location for the servomotors and the apparatus for positioning the shifting ring, so that there are no projections on the inner casing which would interfere with the smooth flow of water. There are likewise no structures on the periphery of the annular frames on which the distributor is mounted, nor is there any necessity for increasing the length of the unit to receive this apparatus. In other words, the form and the length of the unit may be determined solely from the requirements for producing smooth hydraulic flow, without any necessity of compromise for the purpose of providing a space for the apparatus which positions the shifting ring.

This arrangement permits an inclination of the axes of the movable vanes with respect to the axis of the turbine and generator unit, without increasing the length of the unit. This inclination may be between 25 and 55, which range is particularly favorable to a conical flow of water through the turbine.

In one modification of the invention described herein, the servornotors are or the conventional type, including pistons slidably mounted in right cylinders. The cylinders are directly pivoted on the inner casing of the distributor and the piston rods operated by the pistons are pivotally connected to lugs formed on the shifting ring.

In a modified form of the invention the servomotors consist of cylinders of toric form, with toric pistons moving therein. These pistons are fixed to the shifting ring by radial arms, and the toric cylinders are fixed to the frame of the distributor.

The invention will be more fully described with reference to the annexed drawings, which show by way of example several embodiments of the invention. In these embodiments, the apparatus for rotating the distributor vanes is concentrated inside the inner casing upstream from the turbine, without external projections from the casings or from the linings of the water passages.

Fig. l is a fragmentary view taken on a longitudinal section through a portion of a turbine and generator unit constructed in accordance with the invention, with certain parts omitted for clarity.

Fig. 2 is an elevational view taken on the line 11-11 of Fig. 1, looking in the direction of the arrows, with certain parts omitted.

Fig. 3 is a view similar to Fig. 1 showing a modification of the invention.

Fig. 4 is a view similar to Fig. 2 showing still another modification of the invention.

Referring to Figs. 1 and 2, the tubine structure provides an outer casing comprising the crown rings 2 and 11 and the wall continuous therewith and provides an inner casing comprising an internal crown ring 3 and the member 7, these casings being circular in cross-section and concentric upon the axis of the turbine shaft. A distributor for the turbine is shown, including fixed vanes 1, extending between the external crown ring 2, fixed to the outer wall of the water passage, and the internal crown ring 3. The crown ring 3 is provided with an external wall 4 and an internal wall 5. The crown ring 3 is attached at 6 to the member 7.

The distributor includes pivoted vanes 3 carrying on their inner ends supporting pins 9 which are journaled in the member 7. The pivoted vanes 8 carry at their outer ends supporting pins 10 journaled in the crown ring 11 fixed to the crown ring 2. The pivot pins 9 and 10 are axially aligned. The inner ends of the pivot pins 9 carry crank arms 12 connected by pins 13 to links 14 which are connected at their opposite ends by means of pins 15 to an annulus 16 which serves as a shifting ring for the pivoted vanes 8.

The axes of the

pivot pins

9, 13 and 15 intersect at a common point located on the axis of the turbine and generator unit, so that no universal joint is needed in any of the pivot connections. In the particular case of Fig. l, the axes of the pivot pins 15 on the shifting ring are radial, which greatly facilitates their manufacture. While the linkage shown is preferred, other linkage arrangements, such as those including universal joints, may be employed.

The shifting ring 16 is provided with lugs 17, which may, for example, be four in number and symmetrically disposed. These lugs 17 form yokes for receiving pivot pins 18 which pass through piston rods 19 operated by pistons 20 which slide in right cylinders 21. The cylinders 21 and pistons 20 form fluid servomotors. The cylinders 21 are pivotally mounted at their ends opposite the piston rod 19. Preferably this pivotal mounting of the cylinders is carried out by means of pivot pins 22 located in the space between the

walls

4 and 5 of the crown ring. Suitable fluid couplings (not shown) may be provided, as is well-known in the art, to supply fluid under pressure to the opposite ends of the cylinders 21 or to drain them, as required.

When it is desired to change the angle of the vanes 10, the control valve (not shown) of the servomotors operates to supply fluid through the coupling to one end of the servomotor and to connect the other to a drain, so as to establish a difference in the fluid pressure between the two faees of the pistons 20. The pistons are displaced within their cylinders 21 and rotate the shifting ring 16, which actuates the crank arms 13 through the links 14, thereby changing the angular position of the vanes 10.

During rotation of the shifting ring 16, the cylinders 21 pivot on their pins 22.

In the modification shown in Fig. 3, the shifting ring 23 rotates on an internal guide sleeve 24.

In the modification of Fig. 4, the operation of the shifting ring 23 is performed by one or more servomotors in the form of toric cylinders 25 fixed to the wall 26 of the crown ring 3 of the distributor.

Toric pistons 27 slide within the cylinders 25 and are connected by radial arms 28 to the shifting ring 23.

Whenever the servomotors are actuated to drive their pistons, the shifting ring turns through the same angle as the toric pistons.

This invention permits the location of the control apparatus for the movable vanes on a distributor within a minimum space, which permits the use of a streamlined contour for the entire turbine and generator assembly. Furthermore, the construction of the control apparatus is simple, strong and convenient, and eliminates many operating hazards.

It should be understood that the invention is not limited to the particular modifications shown and described, but includes all variations in those structures which are included within the terms of the appended claims.

We claim:

1. Flow distributing apparatus comprising an outer casing, an inner casing, said casings being of circular cross section and concentric and defining between them an annular passage for flow of fluid therethrough, a flow controlling vane within said passage pivotally supported by said casings on an axis extending across said passage between said casings, a shifting ring disposed within said inner casing coaxial with and supported to be rotatively movable upon the common axis of said casing, said ring eing disposed in inwardly spaced parallel relation to and adjacent said inner casing and having a radius upon said axis to provide a substantial space within said ring about said axis, means operatively connecting said vane to said shifting ring for effecting pivotal movement of said vane concurrently with said rotative movement of said shifting ring upon said common axis to adjust the position of said vane in said fiow passage, a toric cylinder disposed within said inner casing and outwardly of said ring with respect to said common axis and supported with the axis of the tore thereof concentric with said common axis, a toric piston movable to and fro within said toric cylinder in the arc of the tore about said common axis, and an operative connection between said toric piston and said ring for rotatively moving said ring forwardly and reversely upon said common axis upon to and fro movement of said toric piston to adjust the position of said vane in said passage.

2. Flow distributing apparatus as defined in claim l in which said operative connection between said toric piston and said shifting ring comprises a rigid member rigidly supported by said ring and extending outwardly therefrom toward said toric piston, and an operative connection between said toric piston and said rigid member to effect movement of said member and of said ring upon said movement of said piston.

3. Flow distributing apparatus comprising an outer casing, an inner casing, said casings being of circular cross section and concentric and defining between them an annular passage for flow of fluid therethrough, a plurality of flow controlling vanes within said passage respectively supported on pivot shafts having their axes extending across said passage between said casings and supported by said casings, a shifting ring disposed within said inner casing coaxial with the common axis of said casings and supported so as to be rotatively movable upon said common axis, said ring being disposed in inwardly spaced parallel relation to and adjacent said inner casing and having a radius upon said axis to provide a substantial space within said ring about said axis, means operatively connecting said pivot shafts to said shifting ring for effecting pivotal movement of said shafts and the respective vanes concurrently with said rotative movement of said shifting ring upon said common axis to adjust the positions of said vanes in said flow passage, a toric cylinder disposed within said inner casing and between said inner casing and said ring and supported by said inner casing with the axis of the tore concentric with said common axis, a toric piston movable to and fro within said toric cylinder in the arc of the tore about said common axis, and an operative connection between said toric piston and said ring for rotatively moving said ring forwardly and reversely upon said common axis upon to and fro movement of said toric piston to adjust the positions of said vanes in said passage.

References Cited in the file of this patent UNITED STATES PATENTS 1,482,405 Moody Feb. 5, 1924 1,728,435 Moody Sept. 17, 1929 1,873,980 Ring Aug. 30, 1932 1,892,187 Drennon Dec. 27, 1932 2,055,134 Pfau Sept. 22, 1936 FOREIGN PATENTS 37,779 Norway Aug.-27, 1923 613,192 Great Britain Nov. 23, 1948