US2876989A - Turbine nozzle construction - Google Patents

Description

March 10, 1959 c. J. BERGSMA 2,87 ,989

TURBINE NOZZLE CONSTRUCTION Filed Aug. 26, 1955 2 Sheets-Sheet 1 INVENTOR. ENEE L1. EREEMA F ZQ V AM ATTUNEY March 1959 c. J. BERGSMA 2,876,989

TURBINE NOZZLE CONSTRUCTION 2 Sheets-Sheet 2 Filed Aug. 26, 1955 'JNVENTOR. CLARENCE A QEREEMA i TU N TURBINE NOZZLE CONSTRUCTION Clarence J. Bergsma, Paramus, N. L, assignor to Curtiss- Wright Corporation, a corporation of Delaware Application August 26, 1955, Serial No. 530,688

4 Claims. (Cl. 253-78) This invention relates to turbines and is particularly directed to a turbine having an annular inlet nozzle construction having a plurality of circumferentially-spaced inlet ports. U. S. Patent No. 2,607,189 to A. Chilton discloses a power plant having gas turbines of this construction, said turbines utilizing the exhaust gases from the cylinders of a piston-type internal combustion engine as the turbine motive fluid.

An object of the present invention comprises the provision of a novel turbine inlet port and nozzle construction in which stresses resulting from unequal thermal expansion and contraction of the various parts are minimized. A further object of the invention comprises the provision of such an inlet port and nozzle construction in which the inlet port can expand and contract relative to the nozzle. A still further object of the invention comprises the provision of a turbine annular nozzle construction having a plurality of circumferentially disposed segmental inlet ports with each inlet port being free to expand and contract relative to the adjacent inlet ports and relative to the annular nozzle.

Other objects of the invention will become apparent upon reading the annexed detailed description in conneetion with the drawing in which:

Fig. 1 is an axial sectional view through a gas turbine embodying the invention;

Fig. 2 is an enlarged view of a portion of Fig. 1; and

Fig. 3 is a bottom end view of Fig. 1.

Referring to the drawing, a gas turbine is illustrated as comprising a stator having an annular nozzle construction 12 for directing the turbine motive fluid against the blades 14 of a turbine rotor 16. The rotor 16 is journaled in the stator 10 by suitable bearing means not shown. The annular nozzle construction includes radially spaced inner and outer walls 18 and 20 across which circumferentially-spaced nozzle vanes 22 extend for properly directing the turbine motive fluid.

The gas turbine illustrated is designed for use as a component of a power plant such as disclosed in the aforementioned Chilton patent so that the turbine motive fluid is the exhaust gases from the cylinders of an internal combustion engine and the turbine rotor 16 is drivably connected to the crankshaft of said engine. The invention is described in connection with this specific application but as will become apparent the invention is not limited thereto.

The exhaust gases discharge from the blades 14 of the turbine through a hood 24 having an exhaust duct 26 extending therefrom. In addition a cap 28 is supported over the turbine rotor disc by a plurality of radial arms 30 extending from a supporting ring 32. The function of the cap 28 is to receive cooling air which is blown (by means not shown) through the turbine rotor between the root ends of the turbine blades, said cooling air discharging from the cap through a discharge end 34 into the exhaust hood 24. A sleeve 36 is secured to the cooling cap support ring 32, said sleeve being disposed around the outer periphery of the rotor blades 14 to provide a ate small operating clearance therebetween. The turbine rotor 16 and cooling cap 28 have been illustrated by dot and dash lines because their specific details form no part of the present invention.

The exhaust hood 24 has an annular flange 26, the cooling cap support ring 32 has an annular flange 38 and the radially outer wall 20 of the nozzle 12 has an annular flange 40, said flanges all extending radially outwardly and being clamped together by a split or two piece clamping ring 42 the ends of which are drawn together by bolts 44. The detailed construction of said flanges and the clamping ring 42 is fully described in copending, application Serial No. 224,167 filed in the name of Francis J. Wiegand on May 2, 1951, now Patent No. 2,811,331. For the purpose of the present invention it is sufiicient to note that the upper wall 46 of the ring 42 is conical and the lower wall 48 is flat so that when the halves of the ring 42 are drawn toward each other about the flanges 26, 38 and 40 said flanges are clamped together. i

As in the aforementioned Chilton'patent the turbine nozzle 12 is provided with a plurality of circumferentiallyspaced inlet ports. In accordance with the present invention, however, in lieu of the one piece inlet port construction of the Chilton patent, a plurality (threeas shown) of individual port members 50 are secured to the nozzle 12 in end-to-end relation.

Each port member 50 comprises a circular segment having a channel-shaped cross-section with the channel curved in a circular arc and having radially spaced inner and outer walls 52 and 54 respectively. Each port member 50 also has an intake pipe 55 through which exhaust gases are supplied to its port member 50 and thence through the nozzle 12 to the turbine rotor blades 14.

For securing the port members 50 to the turbine nozzle 12, the radially inner nozzle wall 18 has an inturned flange 56 and the radially inner wall 52 of each port member has an inturned flange 58. Said flanges 56 and 58 are rigidly secured together by screws 60 which thread into segmental plates 62, there being one such plate for each port member 50. In addition, the radially outer wall 54 of each port member has a flat outwardly extending flange 64 which is arranged to be clamped to the nozzle flange 40 under the clamp ring 42, said nozzle flange 40 also being flat.

With this construction although the inner edge of the segmental port member 50 is rigidly secured to the nozzle 12 by the screws 60 the outer edge of said port member is secured to the nozzle by the clamping engagement of the flat flanges 40 and 64 by means of the clamping ring 42 whereby said port member outer wall 54 can move radially relative to the nozzle as a result of relative thermal expansion and contraction of the nozzle and port member.

One end of each segmental port member has a circumferentially extension 66 which merely overlies the adjacent segmental port member end but is not rigidly secured thereto whereby the segmental port members are free to expand and contract circumferentially relative to each other.

With the aforedescribed construction the nozzle port members 50 can expand and contract relative to the nozzle 12 and relative to each other without imposing excessive stress on any of the parts. In addition, compared to the prior one piece construction, the construction of the present invention simplifies the manufacturing techniques and provides for better quality control. In said prior one piece construction the one piece port member construction was welded to the nozzle. This limited the material of the port members to one which could be welded to the nozzle material. The present invention obviously does not have this limitation and therefore the port members can be made of a better material,

The present construction is also superior to the prior one piece welded" construction, from a service and maintenance standpoint, since now any defect in a particular port rnember only requires replacement of that member.

While Ihave described my invention'in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications.

lclaim as my invention:

1. Turbine mechanism comprising a turbine inlet an nular nozzle structure having radially spaced inner and outer continuous annular walls; a plurality of individual port members for. said nozzle, said port members each having a circular segmental construction and being disposed in end-to-end relation to form an annular arrangement at the inlet side of said nozzle, the adjacent ends of said inlet port members having circumferential clearance therebetween so as to permit relative circumferential expansion and contraction of said members and each of said port members having radially spaced inner and outer walls disposed adjacent to the corresponding nozzle walls; means securingone of said nozzle Walls and the corresponding inlet port walls together; and means frictionally clamping the other of said nozzle and port member walls together, at least one wall of each such pair of clamped walls being flat so as to permit relative radial expansion and contraction therebetween.

2. Turbine mechanism comprising a turbine inlet annular nozzle structure having radially spaced inner and outer continuous annular walls; a plurality of individual port members for said nozzle, said port members each having a circular segmental construction and being disposed in end-to-end relation to form an annular arrangement at the inlet side of said nozzle, the adjacent ends of saidinlet port members having circumferential clearance therebetween so as to permit relative circumferential expansion and contraction of said members and each of said port members having radially spaced inner and outer Walls disposed adjacent to the corresponding nozzle Walls; means securing one of said nozzle Walls and the corresponding inlet port walls together; the other of said nozzle walls and each of the other of said port member walls having a radially extending flange with said port member flanges each having a flat side adjacent to a flat side of said nozzle flange; and annular ring means of channel-shaped cross-section overlying the remote sides of said flanges for trictionally clamping their adjacent flat sides together so as to permit relative radial expansion and contraction between said flanges.

3. Turbine mechanism comprising a turbine inlet annular nozzle structure having radially-spaced inner and outer continuous annular Walls; a plurality of individual inlet port members for said nozzle, said port members having a circular segmental construction and being disposed in end-to-end relation to form an annular arrangement at the inlet end of said nozzle, each of said inlet port members having radially-spaced inner and outer walls disposed adjacent to the corresponding nozzle walls, means for securing one of said nozzle walls to the adjacent port member walls; the other of said nozzle Walls and each of the other of said port member walls having a radially extending flange with said port member flanges each having a flat side disposed adjacent to a flat side of said nozzle flange; and ring means of channel-shaped crosssection having a substantially annular channel with diverging channel sides directed radially inwardly and bridging said flanges; said ring means including means for moving its diverging channel sides radially inwardly toward and about said flanges so that said channel sides overlie the remote sides of said flanges for clamping said adjacent flat flange sides together, one of said channel sides being flat so that the clamping engagement of said channel sides with said flanges does not interfere with relative radial expansion and contraction of said nozzle and port member flanges.

4. Turbine mechanism as recited in claim 3 in which the adjacent ends of said inlet port members have circumferential clearance therebetween so as to permit relative circumferential expansion and contraction of said members.

References Cited in the file of this patent UNITED STATES PATENTS 1,543,172 Losel June 23, 1925 2,253,628 Krapp Aug. 26, 1941 2,391,786 Kenney Dec. 25, 1945 2,494,328 Bloomberg Jan. 10, 1950 2,605,081 Alford July 29, 1952 2,695,131 Price Nov. 23, 1954 2,695,767 Land et a1. Nov. 30, 1954 2,713,990 Wosika July 26, 1955 FOREIGN PATENTS 679,530 Great Britain Sept. 17, 1952 880,773 France Apr. 5, 1943

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