US1472070A - Turbine blading - Google Patents

Description

@@. 3Q, w23 j mm2-m@ A. T. KASLEY TURBINE BLADING` Filed July 5, '1922.

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Patented @et 3C, 1923.

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@lilill ALEXANDER] T. KASLEY, OF ESSINGTON, PENNSYLVANIA, ASSIGNOR TO WESTING- HCUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

TURBINE BLADING.

Application filed July 5, 1922.

T0 all whom t may concern:

Be it known that I, ALEXANDER T. KAS- Lnr, a citizen of the United States, and a resident of Essington, in the ,county of Delaware and State of Pennsylvania, have invented a` new and useful Improvement in Turbine Blading, of which the following is a specification.

My invention relates to turbine blading, more particularly to blading of the wide type adapted to receive. steam. at one side and to discharge it at the tips, and it has for its object to provide apparatus of the character designated which shall be rigid in construction, simple in design, and inexpensive to build.

Apparatus embodying features of my in vention is illustrated in the accompanying drawings, forming a part of this application, in which: Fig. 1 is a. sectional view of a turbine showing my improved typeof blading applied thereto; and Fig. 2 is a fragmentary elevational view as observed from the right vside of the wide bladesl in Fig. 1.

In my co-pending application, Serial No.

521,872, filed December 12, 1921 and as-V signed to lVestingho-use Electric and Manufacturing Company, there is disclosed blading of the wide type adapted to receive steam at one side and to discharge it at the tips. The wide blades disclosed in this application have inner substantially or radial portions and outer curved or spoonoutline portions arranged to expand and to discharge steam at small peripheral angles. Curved ribs or detlector members are arranged between the blades in order to define deiiecting walls to gradually change the direction of steam from an axial toward a radial direction; and, as the rib or deflecting members are in contact, sucli rib or defleeting members constitute bracing means for the blades.

As the tips of wide blading of the character referred to are arranged to discharge directly to the exhaust chamber, there. is a strong natural tendency for the st eam passing between the blades to flow in stream lines under the influence of the highly vacuous conditions fund in the exhaust chamber. This being so, the guide or deliector members need not extend entirely across the space between adjacent blades, and it is, therefore, possible to cheapen the Serial No. 572,901.

construction for the reason that it is unnecessary to accurately tit the guide or deiiector members to constitute curved deflecting walls, as set forth in myv former application. Consequently, the cost of construction int-his respect may be quite materially reduced. Of course, when the guide ribs or detlectors do not contact, the latter do not materially serve to brace the blading structure, and I have, therefore, provided lashing means at the inlet edges of the blades in order to brace the latter.

Referring now to the dra-wings for a more detailed description of my invention, I show a turbine having a rotor 10 and a casing or cylinder 11, with suitable energy-abstracting elements carried tl ereby including a last low-pressure stage, at 12, comprising a stationary row of guide blades 13 and a moving row of wide blades 14 made in accordance with my present invention.

The wide. blades 14 are adapted to receive steam liowing in an axial direction from the row of guide blades or vanes 13 and to discharge the same peripherally or at the tips. Each of the blades 14 comprises Y an inner approximately radial portion 15 and an outer curved or spoon-outline` por-- tion 16. Guide ribs 17 of any suitable type, for example, of the angle-section type, may be formed on or secured to the blade portions 15 in any suitable manner for the purpose of assisting in changing the direction of flow of steam from an axial toward a radial direction. Ahe guide ribs 1'? extend only part way across the spaces between the blades for the reason that the high vacuum condition obtaining in the exhaust chamber results in. a strong natural tendency .for the steam to tlow in stream lines toward the blade tips. I, therefore, provide guide ribs which merely assist this natural tendency.

As the guide ribs 17 do not extend across the spaces between the blades and do not contact, such guide ribs do not serve materially to brace the blading structure. It is, therefore, necessary to provide some means in order to brace or reinforce the blading structure to avoid vibration thereof. Accordingly, I have provided a plurality of lashing members 18 at the inlet edges 19 of the blades let- The inlet edges 19 are preferably inclined, as shown in Fig. 1, in order to provide extra strength to carry the lashing members or Wires. In other Words, the inclination of the entering edges 19 of the `blades presents increasing'stress areas toward the blade roots in order to carry the extra Weight dueto the lashing members.

From the foregoing, it will be apparent that l have devised'blading of the Wide type which has guide or deflect-ing members *for changing the direction of steam which are inexpensive to construct and vwhich dol not require accurate fitting. l have also vised suitable lashing means Vte be used with blading equipped With guide or deiclectoi members oit this character in order to `limit vibration of the blading structure.

While l have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other'changes and modifications, Without depart-ing from the spirit thereof, and l desire, therefore, that only suc-h limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

lflilhat l claim is: y y

l. 'In a turbine, a roiv ot blades having opposed guides on adjacent blade faces which eztend part way across Vthe space between the blades.

2. lna turbine, a row of blades having lashing means cooperating with the blades to limit vibration thereof.

et. ln a turbine, the combination of a row ot blades having opposed and spaced apart guide members on adjacent blade Jfaces and 4lashing means arranged at one side of the side and to discharge it at the tips, opposed and spaced apart guide members on adjacent blade faces for assisting in changing the direction of lovv of steam toward the tips of the blades, and lashing means cooperating` with the inletsides of the blades to limit the vibration thereof. l

6. In a turbine, the combination of a rovi or" exhaust blades adapted to receive steam at one side and to discharge it at the tips, opposed and spaced` apart guide members on adjacent blade faces to assist in changing the direction of flow of steam between the blades :toward the tips, and Vlashing means carried by the inlet edges of the blades, the inlet edges of the blades being inclined so as to provide sufficient supporting structure to Awithstand the centrifugal stresses due to the additional mass of the lashing members. 7. In a turbine, a rovv of tra'pezoidal blades having lashing means at the inclined side. 8. ln a turbine, a row of trapezoidal blades adapted to receive steam at one, Side and to discharge it at the tips, and lashing means arranged at the inclined inlet side.

9. In a turbine, a rovi7 of trapezoidal blades, opposed and spaced ,apartr giuide members carried by adjacent faces of the blades, and lashing means arranged at the inclined inlet side of the blades.

In testimony whereof, I' have hereunto subscribed my name'this 30th day of June,

ALEXANDER T. KASLEY.

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