US2128805A

US2128805A - Support for elastic fluid turbines

Info

Publication number: US2128805A
Application number: US163504A
Authority: US
Inventors: John H Doran
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1937-09-11
Filing date: 1937-09-11
Publication date: 1938-08-30
Anticipated expiration: 1955-08-30

Description

A .30,1938 J. MORAN 2,128,805

I SUPPORT FOR ELASTIC FLUID TUR BINES Filed Sept. 11, 1957 Av mm Inventor": John H. Devan,

His Atfoorney Patented Aug. 30, 1938 lTED STATES 2,128,895 SUPPORT FOR ELASTIE FLUID TURBS John H. Doran, Scotia, N.

Y., assignor to General 5 Claims.

Elastic fluid turbines in order to withstand the high pressures to which they are subjected have relatively massive casings. On account of the hightemperature of the operating fluid, movements of the casing both axially and radially take place due to expansion and contraction from cold to hot and vice versa. Such movements are usually greater in an axial than in a radial direction. The eilects of temperature changes are particularly noticeable at the inlet or high pressure end of the turbine, the low pressure end being anchored. Because such movements cannot be prevented, it becomes imPOr tent to provide means for supporting the casing in such manner that as said movements are taking place and after they are completed, proper alignment of the parts is preserved.

The object of my invention is the provision of an improved means or arrangement of parts which permits the casing of an elastic fluid turbine freely to expand and contract. both axially and radially and at the same time preserves the proper alignment of them-operating parts and prevents distortion of the casing.

For a consideration of what I believe to benovel and my invention, attention is directed to the accompanying specification and the claims appended thereto.

In the attached drawing, which is illustrative of my invention, Fig. 1 is a perspective end view of a turbine and its support; Fig. 2 is a view in elevation of a slightly modified form of support, and Fig. 3 vis a detail showing how the lever arms of the supporting members are connected.

In the drawing, 3 indicates the high pressure end of the casing of an elastic fluid turbine, the parts of which may be of any suitable construction. Extending forwardly from the high pressure end of the casing andparallel to the axis of the shaft of the turbine rotor are two relatively massive arms or

extensions

5 and 5 which sup-- port the front end 0 said casing and of the parts contained therein. The rear or low pressure end of the casing may be supported in any suitable l or known way. The temperature of the low pressure or exhaust end of a turbine when operating condensing, as most large turbines do, is relatively low, and does not change greatly with changes in load, and for that reason it is entirely practical to firmly anchor the exhaust or cold end and take care of expansive movements at the inlet or hot end as in the present case. Under the arms 4 and 5 are located supporting members 6 and I each of which forms a bell "crank lever. The part of each member directly under a supporting arm is of I-beam tormation having a relatively thin web 8 extending at right angles to a plane passing vertically through the axis of the turbine. Each member is rigid in a ver tical plane so as to support the weight of the turbine without flexing. The upper end of the web has an enlarged integral head 9 forming a seat for a supporting arm of the casing, said seat and arm being united by suitable means, as for example bolts ill. The bottom end of the web is provided with an enlarged integral foot ii, the web gradually increasing in width in a transverse plane from the head to the foot. The form or shape of each member is such that the web will bend or yield by the necessary amount when the turbine casing expands'and contracts in the direction of its axis but is rigid against sidewise movements so that the anal alignment of the turbine is preserved.

The radial expansionand contraction of the turbine casing while appreciably less than the axial expansion and contraction thereot nevertheless has to be taken care of. To this end, the base, bed plate or support it has what in effect constitutes a knife edge pivot or fulcrum it for each member. Because the weight of the turbine would tend to crush a true knife edge, the pivot is rounded at upper end so as to give a greater area of support. A pivot or fulcrum. is located in a seat id formed in the foot ll of each member and extends in the same direction as the axis oi the casing. Such a construction permits the members to tilt by the very small but necessary amount when the casing expands and contracts radially. The arrangement of the pivots l3 and seats it also permit the members as a whole, where necessary or desirable, to slide back and forth as the casing expands and contracts but in many cases the vertical webs 8 will bend sumciently for the purpose. To ensure equal movements of the members, as distin-' guished from permitting one to do all or a greater I part of the tilting and thus cause objectionable disalignment of the front end or the turbine casing with respect to the rear or low pressure end, the two members are pivotally connected. Thisis accomplished by providing each member with a lever arm l5 and connecting the two arms by a pivot It. g

Referring to Fig. 2, the same general construction as that referred to above is followed but with the following diderences. Instead of having the relatively larg'e-flat surfaces of the casing arms 5 rest -directly on the heads 9 of the members, there are interposed metal supporting forms nopart of the present invention, it has been 2 amaeoc strips I! of substantially smaller surface arm. Because the supporting strips are narrower than the arms, they in efiect form fulcra and permit of a limited tilting oi the members.

Instead of using knife edge supports iii and seats l4 therefore, as in Fig. 1, narrow supporting strips I 8 are substituted therefor and holding down bolts is provided, the latter being secured in the bed plate 82. The narrow supports in effect form fulcra and; permit of the necessary tilting movement of the members to compensate for radial expansion of the turbine casing. The

axial expansion of the casingmay be taken care of by the bending of the webs ii or the bolts to may be so adjusted and arranged as to permit movement of the members on the base or bed plate if: or a combination of both features may be employed.

In Fig. 3 is shown a suitable arrangement for connecting the lever arms iii of the supporting members and is equally applicable to the structures of Figs. 1 and 2. On opposite sides of one of the arms is secured a pair of plates it by bolts 28 and desirably in addition by a welded joint 22. The other arm is made to .fit between the plates and the parts so fitted are united by a pivot pin 23 having suitable means at its ends to hold it in place.

Since the internal mechanism of the turbine omitted but it is to be understood that it can be of any suitable type. The front end bearing for the rotor is mounted in the forwardly extending part 24 offthe casing so that the entire mass at the front end is supported by the members t and T It must be understood that the movements of the casing due to heat changes are small, so small in fact that usually it is only by accurate measurements that the extent thereof can be determined. Since expansive movements of the casing clue to temperature changes cannot be prevented, the only thing that can be done is to provide supporting, guiding and directingmeans capable of preserving the proper predetermined alignment of the casing anclits parts with respect to some fixed point. The means described above permit the desired results to be secured.

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

1. An elastic fluid turbine having a casing, parts of which move both axially and radially in response to temperature changes, a base, a pair of members extending transversely to the axis of the casing and secured thereto for supporting a part of the weight thereof and preserving the axial alignment of the casing as it expands and contracts in the direction oi its length, said members being yieldable in an axial direction and rigid in a plane perpendicular thereto, fulcrum supports for the members carried by the base permitting the members to tilt as the casing expands and contracts radially, and means connecting the members in a'manner to cause equal tilting movements thereof.

2. An elastic fluid turbine having a casing. parts of which move both axially and radially in response to temperature changes. a base, extensions on.the casing at the hot end thereof on opposite sides of its axis, a supporting member located under each extension and secured thereto for sustaining a part of the weight of the casing and preserving its alignment as it expands and contracts in an axial direction, and means located between the base and the members permitting the latterto tiltln response .to radial expansions of the casing.

3. An elastic fluid turbine having a, casing,-

parts of which move both axially and radially in response to temperature changes of the operating fluid, extenslonson the casing located on opposite sides or" its axis, a, supporting member under each extension and secured thereto, said members being rigid in a vertical plane and movable in the direction of the axis of the casing and also ina plane transverse thereto, means connecting the memhers so that movements thereof due to radial expansion of the casing are equalized, and a base common to and supporting said members.

4. An elastic fluid turbine having a casing, parts of which move both axially and radially in response to temperature changes of the operating fluid, a base, extensions secured to the casing at the hot end thereof and located on opposlm sides of its axis, a pair of members fulcrumeol on the base and engaging the extensions to support the weight of the casing, each of said members form-- ing a bell crank lever, and. means uniting corresponding lever arms of said members in a mannerto equalize their movements in a direction perpendicular to the axis of the casing.

5. An elastic fluid turbine having a casing. parts of which move both axially and radially in response to temperature changes of the operating fluid, a; base, a pair of members supported on the, base, each having a head engaging the casing, a. foot and'a web connecting the heat and foot, said web extending transversely to the axis of the casing and being rigid in a vertical plane and yieldable in an axial direction, and fulcra for the members supported by the base and extending parallel to each other and to the axis of the casing ancl'co-operating with said feet, said members tilting toward and away from each other as the casing expands and contracts radially under temperature changes. Y

JOHN H. DORAN.