US2054142A

US2054142A - Scalable adjustable blade hydraulic

Info

Publication number: US2054142A
Authority: US
Publication date: 1936-09-15
Anticipated expiration: 1953-09-15

Description

Sept. 15, 1936. R. E. B. SHARP 2,054,142

SEALABLE ADJUSTABLE BLADE HYDRAULIC MACHINE 2 Sheets-Sheet 1 Filed Dec. 23, 1933 INVENTOR Sept. 15, 1936. R SHARP 2,054,142

SEALABLE ADJUSTABLE BLADE HYDRAULIC MACHINE Filed Dec. 23, 1933 2 Sheets-Sheet 2 INVENTOR e5. 5. 5/1 5 Patented Sept. 15, 1936 UNITED STATES PATENT OFFICE SEALABLE ADJUSTAlLE BLADE HYDRAULIC HIN E Robert E. Brunswick Sharp, Philadelphia, Pa.,

assignor to Baldwin- Southwark Corporation,

This invention relates generally to adjustable blade hydraulic machines such as turbines or pumps and more particularly to improved means for preventing or minimizing leakage past the turblue blades when they are adjusted to a horizontal shutdown position.

The hydraulic machine specifically shown herein is of the so-called propeller type, the term propeller generically referring to a combination of passages and transition space cooperating with a runner having a relatively few unshrouded blades which are relatively fiat in the direction of fluid flow thereover. It has heretofore been proposed with adjustable bladed propeller ma- IE5:v chines, particularly turbines, to shut down the same by moving the adjustable blades to a horizontal position. The difiiculty with this arrange ment isthe inability to provide a substantially tight closure of the passageway so as to prevent leakage.

It is one object of my invention to providean improved adjustable blade runner and means for effectively and simply insuring a substantially tight seal both around the periphery of the runner and along the radial edges of the adjacent blades when disposed in their shutdown position.

A further and more specific object is to provide improved sealing means adapted to be moved into contact with the runner blades at their periphery or adjacent thereto when the blades are in shutdown position and yet allow proper operating clearance between the runner and its surrounding passage wall during operation of the machine. In one specific aspect of the invention, I provide a fluid controlled expansible and contractible tubular seal imbedded in the passage wall and encircling the runner blade periphery when the blades are in their shutdown position. A further object is to maintain substantial continuity of the passage wall when the sealing means is retracted. A further object is to provide an arrangement of the foregoing type in combination with a fixed gate machine.

Another object is to provide an improved form of blade adapted to produce an effective seal sub stantially throughout the radial contact between adjacent blades when in their closed position and which at the same time will permit efficient operation of the machine. In accomplishing this improved arrangement, the runner is arranged so as to discharge less. water near the hub than would be the case in usual designs, but in accordance with my disclosure this will not appreciably affect 5 the efliciency; in fact the improved advantages resulting from my construction outweigh an such minor disadvantages.

Other objects and advantages will be more apparent to those skilled in the art from the following description of the accompanying drawings in which:

Fig. 1 is a vertical section through a hydraulic machine embodying my invention and also showing suitable blade adjusting mechanism;

Fig. 2 is a vertical section similar to Fig. 1 but showing the runner in elevation in its closed or shutdown position;

Fig. 3 is a plan view of one-half of the runner taken substantially on the line 3-3 of Fig. 2;

Figs. 4 and 5 are vertical sections through adjacent blades taken substantially on the lines 4-4 and 5-5 of Fig. l;

Fig. 6 is an enlarged sectional view of the expansib-le sealing tube.

In the particular embodiment of the invention which is shown herein merely for the purpose of illustrating one specific form among possible others that the invention might take,.1 have disclosed a turbine having upper and lower sections l and 2 of a. throat ring terminating in a draft tube 3. While my invention may be. used with turbines of various settings, yet it isparticularly applicable to a turbine of the open fiume type having fixed guide vanes 4 but are not provided with adjustable. gates or a valve for shutting down the unit. The vanes cause the infiowing fluid to have a whirling action and are supported at their outer ends by the upper bell-shaped inlet 5 while their inner ends support a guide bearing casing 6. The bearing may be of any suitable design to guide a turbine shaft I which carries an unshrouded propeller type runner whose hub is generally indicated at 8'. The outer surface of this hub preferably' forms a continuation of the preferably slightly conical bearing casing 6-.

The carries adiustable blades 9 preferably not more than six in number, these blades extending substantially radially from the runner axis and in spaced relation to guide vanes 4 to provide a vaneefree transition space In, whereby a solid whirling mass of water passes through the runner in a substantially axial direction. It will, of course, be understood that the turbine may be of the diagonal propeller type, wherein the flow passes through the runner with a diagonal component. The blades are adjustably supported by shafts [2 which are join-nailed in hub 8 in a well-known manner. any suitable means may be provided tor simultaneously rotating the blades about the axes of shafts l2 and as such mechanism is well-known, it will suifice to state that one form includes generally a reciprocating blade adjusting rod l3 disposed within the hollow turbine shaft 1, the lower end of said rod having a central hub M from which links l5 project upwardly to engage arms 16, these being secured to the respective shafts l2. Reciprocating movement of rod l3 will therefore cause blades 9 to rotate simultaneously from a substantially horizontal or shutdown position, such as shown in Fig. 2, to different open positions for varying degrees of load and speed. To efiect the reciprocation, there is provided a reciprocating fluid actuated iston l'I secured to rod I3 while fluid is suplied to or discharged from the opposite sides of said piston by any suitable valve controlled passages I8 and is extending upwardly to the free end of the turbine shaft.

The blades are so shaped that when disposed in their shutdown position, as shown in Fig. 2, the adjacent edges of adjacent blades will slightly overlap as shown in Fig. 3. The leading edge of the top blade is at and the trailing edge of the bottom blade is at 2|. It will also be noted from both Figs. 2 and 3 that the contacting surfaces of these edges may be formed along substantially straight radial lines thereby allowing the contacting points or surface of the blades to be easily and accurately machined to insure a substantially tight seal, although the contacting surfaces may be shaped along curved lines in accordance with the hydraulic curvature of the blades. In either case, however, the periphery 22 of the blades when in their closed position is contained substantially in a cylindrical surface, although this could be tapered depending upon the shape of the immediately surrounding wall surface which may be spherical or substantially so.

To effect a simple and yet substantially tight seal between the runner and passage wall when the blades are in their shutdown position, I have provided a tubular sealing element 25 firmly disposed in a recess 26 extending entirely around the throat ring adjacent the runner periphery, the casing if desired being split at this point to facilitate manufacture. This recess terminates in a relatively narrow slot in the wall of the throat ring, whereby the tubular seal which is preferably made of rubber may be expanded through said slot into contact with the blade periphery. This expansion may be effected by controllable means such as inlet 26' adapted to supply fluid pressure to the sealing tube from any suitable source and to release such pressure from the sealing tube to effect contraction thereof so as to provide sufficient clearance for the runner. To insure uniform expansion and contraction of the tubular member, a flexible core 21 is preferablyrsnugly inserted within the tubular member which is pref erably circular in cross-section.

In operation when the pressure in tubular seal 25 is released the tube will assume its retracted position to provide clearance for the runner periphery while at the same time maintaining a substantially continuous passage wall. The blades may then be freely adjusted by actuating the blade adjusting motor l1, thereby to reciprocate shaft l3 and rotate blades 9 about the radial axes of their shafts l2 to start or control the unit. However, when the unit is to be shut down, the motor ll would be reciprocated in the opposite direction to move the blades to the position shown ing Fig. 2, wherein they are brought into overlapping contact with each other along substantially straight radial lines. The turbine thereupon stops, after which fluid pressure is admitted to the tubular seal 26 to expand the same into sealing contact with the runner periphery. The overlapping blades in closed position have such a relatively small inclination to the horizontal that a substantially continuous circle sealing contact with the blades is obtained. As a result a substantially continuous tight peripheral seal may be maintained together with a substantially tight seal from hub to periphery along the straight contacting edges of the blades, while a substantially tight seal between the hub and blades for all posi tions thereof is effected due to the spherical shape of the hub. To obtain this radial contact, th blades are given a configuration as shown in Figs. 4 and 5, this being diiferent from usual shapes and results in the runner discharging somewhat less water in the central portion near the hub than would ordinarily be the case, but this feature i l not appreciably reduce the efficiency. On the contrary, the advantages of my improved surface contact more than offset the negligible loss of eificiency.

It will of course be understood by those skilled in the art that various changes may be made in the details of construction and arrangement of parts without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. A hydraulic machine havingmeans forming a passage, an unshrouded runner disposed therein having blades adapted to be adjusted to an overlapping shutdown position, radially expansible means carried by the wall of said passage and extending continuously around the runner periphery for sealing the same only when in said shutdown position, and controllable means for effecting radial expansion or contraction of said sealing means.

2. A hydraulic machine having means forming a passage, an unshrouded runner disposed therein having blades adapted to be adjusted to an overlapping shutdown position, fluid operated radially expansible means carried by the wall of said passage and extending continuously around the runner periphery for sealing the same only when in said shutdown position, and controllable means for effecting radial expansion or contraction of said sealing means.

3. A hydraulic machine having means forming a passage, an unshrouded runner disposed therein and having blades adapted to be adjusted to an overlapping shutdown position, a radially expansible rubber tubular member carried by the wall of said passage and extending continuously around the runner periphery so as to be expanded in the sealing position against the periphery of the runner blades only when the same are in said shutdown position or to be retracted to an unsealing position, and controllable fluid pressure means for effecting said radial expansion or contraction of said tubular member.

4. A hydraulic machine having means forming a passage, an unshrouded runner disposed therein having blades adapted to be adjusted to an overlapping shutdown position, a radially expansible tubular sealing member carried by and imbedded in the wall of said passage so as to extend continuously around and adjacent to the runner periphery for sealing the same when said runner blades are in said shutdown position, and controllable means for eiiecting radial expansion or contraction of said tubular sealing member.

5. The combination set forth in claim 1 further characterized in that said sealing means includes an annular groove in the wall of said passage adjacent the runner periphery, said groove tcnnpmating in a slot in the surface of the passage wall, and a fluid expansible flexible tubular member disposed within said groove and adapted to be extruded through said slot into contact with the runner periphery or to be retracted so as to maintain a substantially continuous passage wall.

6. A hydraulic machine comprising, in combination; means forming a passage, a propeller type runner disposed therein having a relatively few unshrouded blades which are relatively fiat in the direction of fluid flow thereover, means for rotatably adjusting said blades into overlapping contacting relation to eifect a shutdown position of the machine, said blades being formed so that their line of contact is substantially continuous from periphery to hub, radially expansible means carried by the wall of said passage and extending continuously around the runner periphery for sealing the same only when the runner blades are in their closed shutdown position, and controllable means for eiiecting radial expansion or contraction of said sealing means.

7. A hydraulic machine comprising, in combination, means forming a passage. a propeller type runner disposed therein having a relatively few unshrouded blades which are relatively flat in the direction of fluid flow thereover, means for rotatably adjusting said blades into overlapping contacting relation to effect a shutdown position of the machine, said blades being formed so that their line of contact is substantially along straight radial lines, radially expansible means carried by the wall of said passage and extending continuously around the runner periphery for sealing the same only when the runner blades are in their closed shutdown position, and controllable means for eifecting radial expansion or contraction of said sealing means.

8. A hydraulic machine comprising, in combination, means forming a passage, a propeller t runner disposed therein having a relatively few unshrouded blades adjustable about axes disposed substantially normal to the runner axis and which are relatively flat in the direction of fluid flow thereover, means for rotatably adjusting said blades into overlapping contacting relation to efiect a shutdown position of the machine, said blades being formed so that their line of contact is substantially continuous from periphery to hub, radially expansible means carried by the wall of said passage and extending continuously around the runner periphery for sealing the same only when the runner blades are in their closed shutdown position, and controllable means for effecting radial expansion or contraction of said Sealing means.

ROBERT E. BRUNSWICK SHARP.