US2247378A

US2247378A - Elastic fluid turbine diaphragm supporting and centering arrangement

Info

Publication number: US2247378A
Application number: US315564A
Authority: US
Inventors: Max A Hinrichs
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1940-01-25
Filing date: 1940-01-25
Publication date: 1941-07-01
Anticipated expiration: 1958-07-01

Description

July L 1941. M. A. HINRICHS ELASTIC FLUID TURBINE DIAPHRAGM SUPPORTING AND CENTERING ARRANGEMENT Filed Jan. 25, 1940 Fig.1.

eerwtor: Max Afiinrich His Atk Patented July 1, 1941 ELASTKC FLUID TURBINE DIAPHRAGM SUP- POE/TING AND CENTERING ARRANGE- MENT Max A. Hinrichs, Millbrae, Calitl, assignor to General Electric Company, a corporation of New York Application January 25, 1940, Serial No. 315,564

4 Claims.

The present invention relates to elastic fluid turbine diaphragm supporting and centering arrangements. More specifically the: invention relates to the kind of turbine arrangements in which both the turbine casing and the diaphragms for conducting elastic fluid to the bucket wheels are made of two halves joined together with the diaphragms supported on the casing. Still more particularly the invention relates to diaphragms for conducting the elastic fluid from an extraction or mixed pressure stage to a lower stage and in which one of the dia phragm halves forms a support for a valve body forming a valve seat in cooperative relation with a valve held in the casing. In order to attain the desired operation of such arrangements they have to meet two requirements. First, the extraction'stage diaphragm has to be in concentric relation with the shaft or the rotor of the turbine to assure proper cooperation between a row of nozzles formed by the diaphragm and the buckets of the adjacent bucket wheel. Such concentric relation also assures proper operation of a packing between the diaphragm and the turbine shaft.

Second, the valve seat or seats formed on the valve body must be located ina plane parallel to corresponding surfaces on the movable valve member or members on the casing.

The object of my invention is to provide an improved construction and arrangement of extraction stage diaphragm centering and supporting arrangements whereby the aforementioned requirements aremet in a simple and satisfactory fashion. l

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing, Fig. 1 illustrates a sectional view of an extraction turbine arrangement embodying my invention; Fig. 2 is a view along lines 22 of Fig. 1; Fig. 3 illustrates an enlarged, exploded, perspective view of a part'of Fig. '2; and Fig. 4 is an enlarged sectional viewof a part of Fig. 2'.

The arrangement comprises aturbine casing having lower and upper halves l9 and II respec tively with flanged portions securely joined tol gether in a plane through the'axis of rotation by means of bolts l2. A turbine rotor is disposed within the casing and includes a high pressure bucket wheel l3 and a low pressure bucket wheel l4, both secured to a shaft l5. Elastic fluid is directed to the bucket wheels l3 and M by means of stationary diaphragms l5 and I? respectively supported on the casing. The stages it, I3 and H, M are considerably axially spaced and the lower turbine casing half H] has an opening IB between the two stages for extracting elastic fluid from the turbine or supplying elastic fluid thereto. In case the turbine is operated as an extraction turbine, part of the elastic fluid discharged from the bucket wheel I 3 is extracted through the opening It and the other part is conducted to the lower stage li, Hi. If elastic fluid is supplied through the opening l8 to the turbine, then this elastic fluid together with the. elastic fluid discharged from the bucket wheel 13 is conducted to the bucket wheel l4. Often it is desirable to control the pressure condition ahead of the bucket wheel M in response to changes in flowof fluid through the opening i8. This is accomplished in the present arrangement by a poppet valve arrangement comprising a valve. body l9 centered on and secured to the diaphragm I! by means of a plurality of bolts 26 and a weld 2| and forming valve seats 22 incooperative relation with a plurality of disk valves 23 having stems 24 guided on a cover plate 25 secured to an opening of the turbine casing. The diaphragm I! has a lower half 26 and an upper half 21, the latter. carrying the valve body It and forming a plus rality of nozzle openings 28 arranged to receive elastic fluid from the channel formed by the body l9 and conducting the fluid to the bucket Wheel l4. An outer portion of the diaphragm forms an annular projection 29 projecting into an annulargroove 30 formed by the casing H), H. The diaphragm and the casing form a radial clearance 3| between them to permit of relative expansion.

The projection 29 in the recess 30 on one side 'en-' gages a shoulder formed in the recess and on the other side forms an axial clearance 32, permitting relative axial expansion between the diaphragm and the casing. The diaphragm is forced into contact with the aforementioned shoulder in said recess by the action of steam oration. cured to the diaphragm reduce movement of the diaphragm during shipping and operation. The engagement between the diaphragm I? and the shoulder formed on the caspressure during o ing reduces leakage of elastic fluid along the inner surface of the casing. Leakage along the packing of known construction, and including a packing ring 35 having a plurality of segments held in archbound shaft is reduced by meansof a A plurality of axial crush pins 33 so excessive axial tion of the lower casing half ill,

shaft l5 and that the face 31 of the valve body l9 be parallel to the face 38 of the casing engaging the cover 25. This is accomplished in accordance with my invention by an arrangement for adjustably supporting the diaphragm on and centering it in the casing. More specifically, this arrangement includes means for vertically centering the diaphragm so that its center coincides with the center of the shaft and means for slightly rotating the diaphragm into a position in which the valve seats or the face 31 of the valve body l9 are parallel to the face 38 of the casing.

In the present arrangement the diaphragm halves 26, 21 are centered on each other, that is, prevented from moving axially and laterally relative to each other by means of horizontal keys 40, 4| and a vertical key 42 respectively. The lower diaphragm half 25 is supported on the lower casing half III by lug arrangements 45 and 44 on opposite sides of the diaphragm. Each lug arrangement includes a lug 45 secured in a re cess 46 of the casing by means of a bolt 41 and having a portion projecting into a recess 48 in the diaphragm. The recess 48 is near the upper face of the lower diaphragm half 26 and the lug 45 in the recess 48 is engaged by a screw or threaded pin 49 screwed into a vertical bore between the face of the diaphragm half 25 and the recess 48. Prior to assembly the screws 49 of the lower diaphragm half 25 are adjusted so that the center of the diaphragm coincides with the center of. the casing. The lower diaphragm half is centered vertically in the lower casing by the lug arrangements 43, 44. The upper diaphragm half 21 prior to assembly is similarly centered verticallyin the upper casing half H by means of similar, adjustable lug arrangements 50 and 5| respectively on opposite sides of the upper diaphragm half 21. Prior to assembly the lug arrangements 59, 5! support the upper diaphragm half 21 on the casing half I l whereas subsequent to assembly of the turbine the lug arrangements 50, 5| prevent upward movement of the upper diaphragm half 21 relative to the lower diaphragm half 26. Such lug arrangements are more fully disclosed in the copending applications of Johnson and Wadden, Serial No. 315,548, and Webster, Serial No. 315,547, filed on the same date and assigned to the same assignee as the present application.

The means for circumferentially adjusting the diaphragm comprises an adjustable dowel 52 which has an enlarged lower portion 53 rigidly held in a vertical opening 54 in the bottom por- An upper portion 55 of the dowel 52 projects into a recess or slot 56 in the lower portion of the lower diaphragm half 26 and is provided with a cross pin or screw 51 adjustably secured to, in the present instance screwed into, the-upper portion 55 of the dowel pin 52. As best shown in Fig. 4, the length of the cross pin 51 is equal to the circumferential width of the recess 55 and the diameter of the upper portion 55 of the dowel pin in the present example is somewhat smaller than the circumferential width of the recess 55. Opposite sidesof the upper portion 55 through which the cross pin 51 projects are flattened to permit increased adjustment of the cross pin 51.

With such an arrangement the diaphragm may be rotated slightly by adjustment of the cross pin 51 or, from another viewpoint, adjustment of the cross pin 51 upon removal of the diaphragm from the casing necessitates slight rotation of the diaphragm. If upon assembly of the turbine casings it is found, for example, that the left-hand side (Fig. 2) of the face 31 is too low and the right-hand side (Fig. 2) of the face 31 is too high, the upper casing half is lifted from the lower casing half and the cross pin 51 is turned clockwise from the right-hand side so that the pin projects more to the left. This of necessity requires slight circumferential movement or rotation of the lower diaphragm half in clockwise direction. To permit of such movement and to assure proper support on the lugs 45, the screw 49 on the left-hand side is turned clockwise and the screw 49 on the right-hand side is turned counterclockwise. right-handed.) In this manner the lower diaphragm half is slightly turned and maintained concentric with the shaft though its upper face isno longer horizontal and in a plane with the joint of the casing halves II], II, it suflicing that the center of the lower diaphragm half coincides with the center of the shaft.

Horizontal adjustment of the lower diaphragm half requires similar adjustment of the upper diaphragm half. In the above example where the left-hand screw 49 has been turned clockwise and thereby the left-hand portion of the lower diaphragm half 26 moved upward it becomes necessary to turn the screw 49 on the left-hand side of the upper diaphragm half counterclockwise and the screw 49 on the right-hand side of the upper diaphragm half 21 clockwise.

If upon assembly of the turbine casings with the diaphragms it is found that the left-hand side of the face 31 of the valve body I9 is too high or, from another viewpoint, that the plane of the face 31 of the valve body and the plane of the face 38 of the casing converge towards the left, the adjustable cross pin 51 and the screws or pins 49 of the lug arrangements are adjusted similarly as described above except that they are then turned in the opposite direction as before.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Elastic fluid turbine diaphragm centering and supporting arrangement comprising a turbine casing, an intermediate stage diaphragm disposed within and engaging a shoulder on the casing, means controlling the flow of fluid to the diaphragm comprising a valve body forming a 2. Elastic fluid turbine diaphragm centering and supporting arrangement comprising a casing having lower and upper halves with an opening in one of the halves for extracting fluid from or supplying fluid to an intermediate stage, a diaphragm for conducting elastic fluid from such intermediate stage to the'succeeding stage, such diaphragm having two halves, means for con (All screws 49 and 51 are trolling the flow of fluid through the diaphragm comprising a valve body forming a valve seat secured to one of the diaphragm halves and a movable valve member in cooperative relation with the seat and supported on the casing, and means supporting and centering seat is parallel to the cooperating surface of the movable valve member.

3. Elastic fluid turbine diaphragm centering and supporting arrangement comprising a casing having lower and upper halves with an opening in one of the halves for extracting fluid from adjustable means supporting and centering the diaphragm on the casing, said means comprising a lug arrangement on each side of each diaally outward from the flattened sides of the other portion for engaging the wall of such recess.

MAX A. HINRICHS.