US1544288A - Turbine blading - Google Patents

Description

June 30, 1925. 1,544,288

B. w. VAN ORMER TURBINE BLAD LNG Filed s- 15. 1923 Z5 27 DZ 29 4.0

\ v 38 as INVENTOR ATTORNEY Patented June 30, 1925 UNITED STATES PeTENT clerics BANKS W. VAN OB-MER, or noLs'o'M, PEN'NsYnvANIA, ASSIGNQR "ro W'EST'INGHOUSE ELECTRIC AND MANUFACTURING GQM'BANY, A con ravention or PENNSYLVANIA.

TURBINE BLADIINGV Application filed Augu t 13, 1923. S ial No. 657,129.

To all whom it may concern:

Be it known that I, BANKs W; VAN ORMER, a citizen of the United States, and a resident of Folsom, in the county of Delaware and State of Pennsylvania, have invented a new and useful Improvement in TurbineBlading, of which the following is a specification.

My invention relates to elastic-fluid turbines, and it has for its object to provide low-pressure blading for apparatus of this character which shall be capable of automatic adjustment to provide better paths for the flow of steam under variable load conditions.

A further object of my invention is to provide one or more rows of stationary lowpressure blades, each of which is capable of flexing transversely in accordance with the velocity of elastic fluid passing therethrough. V

In the operation of elastic-fluid turbines it is found that, at light loads, blading at the low-pressure end may abstract little, if any, energy from the elastic fluid owing to the fact that the energy has been very largely abstracted by preceding stages. Under such a condition, reduced velocity elastic fluid acts upon 'blading of the conventional type in such a way as to reduce the over-all efliciency of the turbine over that which would exist if the inactive blading could be omitted. In accordance with my invention, I provide transversely flexible capable of automatic adjustment in accordance with the elastic-fiuid velocity so as to provide better paths for the passage of elastic fluid under different operating conditions. In case of normal load, the transversely flexible blades flex due to the impact of elastic fluid to provide curved surfaces such as the normal blade would have for the purpose of properly directing the elastic fluid to the following row of moving blades. In case the turbine load should drop and theimpactive force of the steam against the transversely flexible blades should be sufficiently reduced, the latter blades will automatically straighten out so as to provide paths therebetween which shall permit of the passage of steam with a minimum degree of turning. In other words, it is the object of my invention to stationary. low-pressure blades which are provide low-pressure bladingwhich hall be capable of discharging elastic fluid with a minimum degree of resi's'tance'when operating at light loads.

A paratus made in accordance with m inventionis illustrated in the accompanying drawings, forming a part of this application, in which Fig, 1 is a detail sectional view of turbine blading incorporating m invention; 2 is a sectional v ew taken along the lineIL-II of Fig. 1 Fig; 3- is a view similar to Fig. 1, but showing a modifiedf'orm of my invention; and Fig. 4: is a detail View of a supporting element for use in connection with my improved blading'.

Referring now to the drawings for a better understanding of my invention, in Fig. 1-, I show a rotor 10 carrying" moving rows of blades lland 12 and a casing 01' stator 13 carrying a stationary row of blades 14. The stationary blades 14 constitute the subject of my invention a ndthey will now be described.

The stationary blades 14 are shown being made up of a plurality of hinged sections 15, 16 and 17 and, while I show three such hinged sections, it is to be understood that any suitable number may be employed.- The hinged section 15 adjacent to the row of moving blades 11, is provided with inner and outer trunnions 18 and 19 Which'fit in sockets 20 and 21 provided, respectively, 'in the inner and outer rings 22 and 23. The rings 22 and 23 are provided with rod portions 21 and 25 which fit in openings 26 and 27 provided in the shroud ring 28 and in the base ring 29, respectively; Springs 30 and 31"are arranged within the openings 26 and 27, respectively, and adjustable abut ments 32 and 33 cooperate with the outer ends of such springs so that the degree of compression thereon may be adjusted in order to vary the tendency of the rings 22 and 23 to'mo've toward the moving blades11.

The sections 17 adjacent tothe moving row of blades '12 are provided With'tlunnions 35 and 36 which'fit openings 37 and 38, provided, respectively, in the shroud ring 28 and in the base or holding ring 29.

From the structure described, it will be and 29 are preferably made in sections which are connected together by rigid radial webs 42, as may be seen from Fig-.4.

In Fig. 3, I show a further modified form of my invention in which the transversely flexible blades are each made in a single piece, thereby avoiding the hinged construction and the necessity of using twopart, supporting-ring structures. view, I show transversely flexible stationary blades 45 carried byinner and outer rings 46 and 47-, respectively, the ring '46 serving as a shroudring and the ring 47 being secured to the stator 13 in a manner similar to the ring 29 already referred to. The blades have inner trunnions 48 and outer trunnions 49 which fit openings 50 and 51, respectively, in the rings 46 and 47 respectively. The entrance sides of the blades 45 are provided with trunnions 52 and 53 which fit slots 54 and 55, respectively, in the rings 46 and 47, respectively. The slots 54 and 55 are of sufliclent length sothat, when the trunnions52 and 53 are at the forward ends thereof, the blades 45 completely straighten out; When the trunnions 52 and 53 occupy the rear ends of the slots 54 and 55, the blades 45 are curved transversely. Blades made in'accordance with this modification are made of some flexible material, preferably steel, and are necessarily thin enough in cross-section to bend when'subjected to the impact of motive fluid.

The operation of apparatus made in accordance wlth my inventlon 1s as follows:

After passage through the higher pressurestagesof the turbine, elastic fluid enters the moving row of blades 11, then passesbetween the transversely flexible blades 14, of Fig. 1,, or 45 of Fig.3, and'then enters between the last row of moving blades 12 from which it is discharged'to the exhaust. \Vith sufiiciently light loads, steam leaves the moving row of blades 11 at such low velocity that the impactive force thereof against the transversely flexible blades is overbalanced' by the effective force of the springs 30 and 31, of Fig. 1, or of the inherent flexibility of the blades 45, of Fig; 3, with the result that the transversely flexible bladesstraighten out to provide substantially straight paths for the flow of steam therebetween.

The transversely flexible blades, there- 4 fore. serve to provide paths having mini- In this preceding blading. The reason for this is 7 that passing of relatively inert steam in curved paths between stationary blades is avoided. With a suflicient increase in load,

the velocity of steam discharged from the i row of blades 11 increases; and, with a sufficient velocity increase, the impactive force of the steam acting against the transversely flexible blades, becomes sufiicient to cause the latter to assume a normally trans versely curved outline in order to present inlet edges at the proper angle for the reception of steam from the blades 11- and to present outlet edges at the proper angle for the discharge of steam for entrance between the blades 12. 1

It is to be understood that the two types of construction for the transversely flexible stationary blades are referred to by way of example only, and that any suitable construction might be used so long as these blades are capable of flexingin this way for the purposestated. I

WVhile I have shown my invention in but two forms, 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 departingv from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposedby the prior art, or as are specifically set forth in the appended claims.

What I claim is:

1. In a turbine, the combination of'a row of moving blades followedby a row of transversely flexible stationary blades.

2. In a turbine, the combination of a row of moving blades followed by a row of trans versely flexible blades and means for normally exerting a straightening-out influence on the latter.

3. In a turbine, a row of stationary blades each of which consists of a' plurality of hinged sections, and spring means normally tending to straighten out the sections.

4. In a turbine, a row of stationary blades,

each of which consists ofa plurality of hinged sections, means for-supporting the,

rear section of each blade, and spring means tendmg normally to move the forward section so as to straighten out the hinged sectransverse contours from the inlet to the outlet edges thereof are dependent upon the velocity of motive fluid discharged by the moving blades.

7 In a turbine, the combination of a roW of moving blades, a row of stationary transversely adjustable blades following the mov ing blades and Whose transverse contours are dependent upon the velocity of motive fluid discharged by the moving blades, and further blading following blades.

said adjustable 10 In testimony whereof, I have hereunto subscribed 1923 my name this 30th day of July

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