US1585670A - Elastic-fluid turbine - Google Patents

Description

May 25 1926.

H. J- HANZLIK ELASTIC FLUID TURBINE Filed NOV. 11, 1924 INVENTOR WITNESSES:

ATTORNEY Patented May 25, 1926.

UNITED. STATE PATENT OFFICE.

HENRY J'. HANZLIK, OF SWARTHMORE, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VAN IA.

ELASTIC-FLUID TURBINE.

Application filed November 11, 1924. Serial No. 749,289.

My invention relates to elastic-fluid turbines, more particularly to that class of turbines wherein the motive fluid is expanded in one direction through a plurality oI stages entailing an end thrust on the turbine rotor, and wherein a dummy piston with cooperating stationary and moving packing elements is employed, said dummy piston being acted upon by the motive fluid in a direction opposite to the direction of expansion to offset the end thrust on the rotor, and it has for an object the provlsion of apparatus of the character designated which shall be simple of design, easy of manufacture, and reliable of operation.

More specifically the object of my invention is the provision of a stationary blade, or packing element-carrying ring for a turbine which, in operation, shall be free from distortion due to pressure and temperature differences acting thereagainst.

In the accompanying drawing forming a part of the specification, the single figure is a fragmentary sectional view of .a turbine having my improved blade or packing element-carrying ring applied thereto.

In the design of. elastic-fluid turbines wherein the motive fluid i expanded in one axial direction through a plurality of stages, the rotor of the turbine is usually provided with a dummy piston against which the motive fluid acts in a direction opposite to the direction of expansion in order to counteract the end thrust on the rotor caused by the motive fluid acting in one direction through the various stages. The dummy piston is provided with moving rows of packing strips, or elements, which cooperate with complemental rows of elements carried by a stationary member.

In such apparatus much closer clearances are maintained between the cooperating stationary and moving parts surrounding the dummy piston than in other parts of the turbine. Where a simple ring has been employed for carrying the stationary parts, distortion thereof has occurred upon rubbing and local heating of the ring. To overcome this difliculty it has been proposed to provide the ring with a radially extending stiffening web, securing the ring to the casing at the outer periphery of the web and providing packing means between the ring and the casing at the outer periphery of the web in order to prevent leakage thereby. \Vhile this construction has served to prevent distortion due to local heating of the ring, difliculties have been encountered due to the increased area of the ring provided by the stiffening web being subjected on its two sides to different pressures and temperatures of the motive fluid. The difierent pressures and temperatures acting against the two sides of the increased area of the ring have a tendency to distort the ring by bending it outwardly toward the region of lower pressure and temperature.

In accordance with my invention I employ a ring for carrying the stationary packing elements having a radially extending stiffening web, and secure the ring by its base portion to the casing, sufficient clearance being provided between the stifiening web and the casing to permit the motive fluid to pass freely around it. Packing means are provided between the base portion of the ring and the casing so that the stifl'en ing web is subjected on both sides to the same pressure and temperature and distortion thereof is prevented.

Referring now to the drawing for a better understanding of my invention, I show in Fig. 1, at 10, a portion'of an elasticfiuid turbine embodyinga casing 11 and a rotor 12. At 13 I show a stage of impulse blading and at 14; a plurality of stages of reaction blading. Motive fluid for the turbine is admitted at 15 and is expanded through the various stages toward the left in the drawing. The action of the motive fluid being expanded through the various.v stages tends to force the rotor 12 toward the left, entailing a heavy end thrust thereon.

In order to offset the end thrust on the rotor a dummy piston 16 is provided and embodied in the rotor 12, said dummy piston being subjected to the pressure of the motive fluid entering the impulse stage 13 through the inlet 15. It will be seen that this pressure acts in a direction opposite to the direction of expansion of the motive fluid and thus counteracts the end thrust on the rotor due to the expansion of the motive fluid in one direction. In order to prevent leakage by the dummy piston 16 a plurality of moving packing elements 17-47 are provided thereon. The packing elements 1717 are usually in the form of strips surrounding the dummy piston and they cooperate with complemental stationary elements 1818 for preventing leakage by the dummy piston 16. The stationary packing element's 1818 are carried by a ringl'i) which surrounds the dummy piston 16. The ring 19 comprises an axially extending base portion 21 and a radially extending stiffening web 22, I secure the ring,

19 to the casing 11 by its base portion and to this/end I provide the base portion 21 with an outwardly turned annular flange 23 which fits into a eomplemental groove 24 formed in a shoulder 26 on the interior of the casing 11. \Vith the ring 19 secured in this manner it will be seen that the same pressure and temperature ofmotive fluid is present at all times on both sides of the web portion 22 and acts equally around the base portion. 21 so that there can be no distortion due to pressure and temperature differences.

In order to prevent leakage by the ring 19 into the outer end-of the turbine casing, I provide packing means 27 which fits into complemental grooves formed in the base portion of the ring 21 and the casing 11 and prevents leakage thereby.

.From the foregoing it' will be apparent that I have invented an improved packing element-carrying ring for a turbine dummy piston, together with means for securing said ring to the casing whereby the entire area of the outer portion of thering is subjected at all times to the same pressure and temperature and distortion is prevented.

Vhile I have shown my invention in but one form, it will be obvious to those skilled in the artthat it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire therefore that only such limitations shall be placed thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What Iclaim is:

1. In a turbine having a casing and a rotor, said rotor embodying a dummy piston, a stationary packing element-carrying ring surrounding the dummy piston, said ring having a base portion for carrying the stationary packing-elements, and a radially extending web portion for stiffening the ring, means securing the stationary packing element-carrying ring to the casing only atthe base portion of the ring, whereby the same pressure and temperature exists on both sides of the web portion.

2. In a turbine having a casing and a rotor, said rotor embodying a dummy pis ton, a stationary packing element-carrying .ring surrounding the dummy piston, said ring comprising an axiallyextending base portion anda radially ext-ending web portion, an annular shoulder on the casing adjacent to the ring, and means cooperating between the base portion of the ring and the annular shoulder on the casing for supporting the ring.

3. In a turbine having a easing and a rotor, said rotor embodying dummy piston, a stationary packing element-carrying ring surrounding the dummy piston, said ring comprising an axially extending base portion and a nidially extending web portion, an annular shoulder on the casing adjacent to thering, means cooperating between the base portion of the ring and the annular shoulder on the casing for supporting the ring, and packing means between the casing and the ring. a

i. In aturbine having a casing and a rotor, said rotor :embodyinga dummy piston, a stationary packing elementcarrying ring surrounding the dummy piston, said ring comprising an axially extending base portion and a radially extending web portion, an annular shoulder on the casing ad jacent to the ring, said shoulder having an annular groove provided therein, and a flange on the base of the ring fitting into the annular groove.

5. In a turbine having a casing and a rotor, said rotor embodying adummy piston, a stationary packing element-carrying ring surrounding the dummy piston, said ring comprising an axially extending base portion and a radially extending web portion, an annular shoulder on the casing adj acent to the ring, said shoulder having an annular groove provided therein, a flange on the base of the ring fitting into the annular groove, and packingmeans between the base of the ring and thecasing.

6; In a turbine having a casing and a rotor, said rotor embodying a dummy piston, a stationary packing element-carrying ring surrounding the dummy piston, said ring comprising an axiallyextending base portion and a radially extending web portion, an annular shoulder on the casing adjacent to and overhanging the base of the ring, said shoulder having an annular groove provided therein, a radially extending flange on the base ofthe ring fitting into the annular groove, and'packing means between'the base of the ring and the casing.

7. In a turbine embodying a rotor, a casing and a plurality of energy abstracting stages wherein the motive fluid is expanded while moving in an axial direction, a dummy piston included with the rotor, means for subjecting the dummy piston to the expansive force of the motive fluid in a direction opposite to the direction of expansion, a plurality of rows of cooperating moving and stationary packing means for preventing leakage by the dummy piston, a ring comprising an ax ally extend ng base portion for carrying the stationary packing means and a radially extending Web portion for stiffening the ring, an outwardly turned flange on the base portion of the ring, the shoulder on the casing adjacent the base portion of the ring, said shoulder being bored With an annular groove fitting over the outwardly turned flange on the base portion of the ring, and a packing strip disposed between the base of the ring and the casing.

8. In a turbine embodying a casing, a rotor, a plurality of stages through Which the motive fluid is expanded in one direction and a dummy piston on the rotor against which the motive fluid acts in a direction opposite to the direction of expanelements cooperating with the moving blades for preventing leakage by the dummy piston, a ring having a radially extending stiflening Web and a base portion for carrying the stationary packing elements, a flange on the base portion of the ring, and a shoulder on the casing having a complemental bore fitting over the flange.

In testimony whereof, I have hereunto subscribed my name this twenty-fourth day of October 1924.

HENRY J. HANZLIK.

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