US2638312A

US2638312A - Turbine wheel

Info

Publication number: US2638312A
Application number: US716147A
Authority: US
Inventors: Jedrzykowski Edmund
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1946-12-13
Filing date: 1946-12-13
Publication date: 1953-05-12
Anticipated expiration: 1970-05-12

Description

E. JEDRZYKOWSKI TURBINE WHEEL May 12, 1953 Filed Dec. 15, 1946 2 Sheets-Sheet l INVENTOR. gylomsyz PM May 12, 1953 E. JEDRZYKOWSKI 1 163 3 TURBINE WHEEL Filed Dec. 13, 1946 2 Sheets-Sheet 2 INVENTOR. 2271222025 efea r yloz Asjz Patented May 12, 1953 UNITED STATES PATENT OFFICE International Harvester Company, a

tion of New Jersey corpora- Application December 13, 1946, Serial No. 116,147

7 Claims.

This invention concerns gas turbines or blowers, and relates more particularly to an improved wheel therefor with separately formed blades and means for attaching the blades to the wheel.

The general object of the invention is the provision of an improved turbine or blower wheel susceptible of production with intricately shaped blades by a method free of costly machining steps.

A more specific object is the provision of an improved turbine wheel structure wherein the shanks of separately formed turbine blades are retained within peripheral slots of the wheel by a novel arrangement of welding metal disposed within end face recess means of the wheel.

Another object is the provision of a new turbine wheel blade comprising vane and shank portions individually shaped as desired from a single piece of suitable material.

A further object is the provision of a turbine wheel having blade-receiving slots formed in the circular periphery thereof in a fashion extending between opposite end faces of the wheel and curved about individual axes extending perpendicularly to the axis of the wheel; and the invention also encompasses the process of forming these peripheral slots.

These and other desirable objects encompassed by the invention together with numerous advantages will become apparent from the ensuing description and the annexed drawings, wherein:

Fig. 1 is an end elevational view of a turbine wheel embodying features of the present invention.

Fig. 2 is a side view of the turbine wheel of Fig. l, partly in elevation and partly in section.

Figs. 3, 4, and are sectional views taken respectively on the lines 33, 4-4, and 55 of Fig. 2.

Fig. 6 is a fragmentary end elevational view of a turbine wheel structure embody ng a modified form of the invention.

Fig. 7 is a fragmentary side view of the wheel structure shown in Fig. 6, partly in elevation and partly in section.

Figs. 8 and 9 are sectional views taken on with a shaft 13. The wheel [2 has a series of slots I4 formed in its circular periphery in circumferentially spaced relation." These slots extend completely between opposite end'faces l5 and IQ of the wheel I2 and thereby form a series of circumferentially spaced teeth I! upon the wheel periphery, the slots constituting spaces between said teeth. Opposite end surfaces of the teeth Il constitute radial extensions of the opposite end faces I5 and [6 of the wheel.

Recess means in the form of a pair of circular recesses l8 and 19 are formed in the wheel end face l6 concentrically with'the 'wheel axis and of such diameter that the recess means [8 intersects solely the extension portions of the face l6 upon the ends of the teeth H while the recess means I9 is formed partly upon the main portion of the face 5 and" partly upon the radial extensions of this face carried by the ends of the teeth l1. Both of therecess means 18 and I9 communicate with the slots or spaces between the teeth ll. Recess means inthe form of circular recesses 2| and 22, respectively, corresponding to the recesses l8 and I9, is formed in the opposite end of the wheel. Notches 23 are formed in the outer ends of the teeth ll. These notches may be formed by a cutting tool while the wheel I2 is rotated upon a turning lathe.

Identical blades 25 are-assembled in the slots M of the wheel l2. These blades are forged or stamped from single pieces of metal. Each blade 25 has an end portion comprising a transversely curved vane or bucket 26 and an opposite planar end portion 21 constituting a shank insertable into one of the wheel slots M. The concave face 28 of each vane 26 is upon the obverse face of its blade, while the convex face 29 of each blade is on the reverse face ofits blade. Figs. 1 and 4 illustrate that the blade shanks 21 are offset inwardly, toward the obverse faces of the blades, from the reverse faces of their blades. A dished or concavo-convex rib 3| projects rearwardly from the reverse face of each blade shank 21 and extends lengthwise of the blade as illustrated in Fig. 2 into joining relationwith the associated vane 26. These ribs 3| which rigidify the blade structure are accommodated by the tooth notches 23 when the blades are assembled with the wheel proper l2. 7

The blade shanks are so constructed and arranged that when they are inserted into the wheel slots N, no part of said shanks obstruct the circular recess means [8, l9, 2i, and 22. This is accomplished by forming

notches

32 and 33 in opposite edges of the shanksfor circumferential registry with the recess means l8 and 2|, and by forming cut-away

portions

34 and 35 for respective re istration with the circular recess means is! and 22. Notches 32-43 and cut-away portions 3 .l35 provide clearance spaces registering with the recess means l8, 19. 2|, 22 and thus avoid obstructing circumferential continuity of this recess means. 7 I I While the blades are held in assembly with the wheel proper H! by temporary means (not shown) welding metal is laid within the unobstructed rooves or recess means l8, l9, 2|, and 22 and caused to establish a welded union between the sides of said recess means and the sides of the h blade shank notches 32 and-33 and the sides'fof. the blade shank cut-

away portions

34 and 35. Excess welding material is ground away for causing the

rings

35, 31, 38. and 39 of metal filling the recess means to present a surface flush with that of the wheel faces i5 and it. Each of these welding metal rings is vioined to the blades and the outer, 3t and 38. of said rings further function as keys within theashank notches 32'. and 33 for resisting the great centrifugal force exerted by these blades when the wheelistructure is rotated at tremendous speed in operation.

The second form of turbine wheel structure illustrated in Figs. 6 to 11 has a wheel proper 12c correspondin to the wheel 12 of the first embodiment. The end faces of the wheel lZa contain recess means I911 and 22a corresponding to the recess means i9 and 22' in the first embodiment, and circular rings 3la'and 39a of weldin metal are disposed in the recess means in welding relation thereto and to cut-away portions AI and 42 of shanks 43 of turbine blades 44.

Both the shanks 53 and buckets or vanes 45 of the blades M are transversely curved as illustrated in 3 and 9, the obverse facesof the blades including the concave sides of the'vanes and shanks while the reverse faces of theblades include convex sides of the vanes and the shanks.

Because of the blades M being transversely curved throughout their length, the need for a reinforcin rib as 3! in the first embodiment is avoided. However, it is necessary for'the blade shank receiving slots 46 to be curved as illustrated in Fig. 10 to conform to the blade shanks. Curved slots are formed by using a crown saw or milling tool M as illustrated in Figs. 10 and 11. This tool is rotated about an axis a--a which is spaced transversely from the axis 1) of the wheel 12a and is directed perpendicularly to the axis 17: see Fig. 11. This places one edge portion 4B of the circular cutter i! substantially in radial alignment with the axis'b for properly cutting the slots 45 when the wheel and cutter are moved toward one another axiallyof the axis a/a. In performing the notch cutting operations, the wheel In is intermittently rotated for successively carrying circular peripheral portions thereof (wherein the slots 46 are to be cut) into registry with the cutter portion 48. While each of these peripheral portions in which the slots are to be cut is in re istry with the cutter portion 48, the rotating cutter and the wheel i211 are relatively moved along the axis aa, first for cutting the slot and then for separating the cutter and the wheel preparatory to the succeeding indexing movement of the wheel.

Turbine wheels constructed according to the present invention need have only the blades thereof made of the costly relatively hard heat resisting metal. The wheel i2 may be made of a softer, less expensive and more easily machined metal.

In addition to the saving in material cost of the complete Wheel unit H including the blades. the fabricating or forming operations performed upon the blades involve a minimum of machining and are otherwise relatively economical.

Having thus described a limited number of embodiments of the invention with the view of clearly and concisely illustrating the same, I claim:

1. In combination, a turbine wheel having circumferentially spaced peripheral slots communicating between opposite end faces of such wheel. said wheel also having recess means extendin circumferentially of the wheel within at least one of said end faces in intersecting relation with end portions of said slots, blades associated with said slots, said blades including shanks respectively disposed in said slots and having notched edges disposed. substantially flush with the end faces of said wheel, the notches; of said blade shanks registering with said recess means circumferentialh of the wheel, and means for anchoring said shanks in said slots comprising a rin of weldin metal disposed in said recess means and in the shank notches. and said ring of metal having a weld union with the sides of said recess means and with the sides of said notches.

2. In combination, a turbine wheel having circumferentially spaced teeth projecting radially therefrom, said teeth having opposite ends constituting radial extensions of opposite end faces of said wheel, said teeth also having notches within their radial outer ends, blades for notches. each blade having an obverse side and. a reverse side, each blade having a vane at one end and a shank at the other end offset inwardly from the reverse face of its vane, and a rib on the reverse face of the shank to serve as a rigidifyine connecting means between vane and shank, said blades being assembled with the wheel by the disposal of said blade shanks respectively in the spaces between said teeth, said ribs being disposed respectively within said notches of the teeth, and means for anchoring said shanks in said assembly comprising recess means in at least one of said end faces communicative with the spaces between said teeth, and welding metal in said recess means in welded union with the side walls thereof and with the blade shanks.

3. In combination, a turbine wheel having circumferentially spaced teeth projecting radially therefrom, said teeth having opposite ends constituting radial extensions of opposite end faces of said wheel, said teeth also having notches within their radial outer ends, blades for said notches. each blade having an obverse side and a reverse side, each blade having a transversely curved vane at one end and a planar shank at the other end, the concave side of each vane being on the obverse side of its blade, and said shanks being oilset inwardly from the reverse face of their associ ated vanes, each blade also comprising a concave concave rib extending axially thereof along the reverse face of its shank and joining with its vane, the concave side of each rib being on the obverse side of its blade, said blades being assembled with the wheel by the disposal of said blade shanks respectively in the spaces between said teeth, said ribs being disposed respectively within said notches of the teeth, and means for anchoring said shanks in said assembly comprising recess means in at least one of said end faces communicative with the spaces between said teeth, and welding metal in said recess means in welded union with the side walls thereof and with the blade shanks.

4. A turbine blade having obverse and reverse sides, one end of said blade being transversely curved and constituting a vane of which the concave face is upon the obverse side of the blade, the other end of said blade constituting a shank offset inwardly from the reverse face of said vane, said blade also comprising a rib on the reverse face of said shank and extending lengthwise of the blade into joining relation with the vane.

5. The combination set forth in claim 4 wherein said rib is a concavo-convex structure of which the concave side forms a portion of the obverse side of said blade.

6. A turbine blade having obverse and reverse sides, an end portion of said blade being transversely curved and comprising a vane of which the concave side is upon the obverse side of said blade, the opposite end portion of said blade being substantially planar and comprising a blade shank oifset inwardly from the convex side of said vane, said blade also comprising a concavo-convex rib projecting rearwardly from the reverse side of said shank and extending lengthwise of the blade into joining relation with said vane, and the concave side of said rib being a portion of the obverse face of said blade.

'7. In combination, a turbine wheel having circumferentially spaced peripheral slots communicating between opposite end faces of such wheel, said wheel also having recess means extending circumferentially within at least one of said end faces in intersecting relation with ends of said slots, blades associated with said slots, said blades having shanks respectively disposed in said slots, said blade shanks having opposite edges respectively in flush relation with the wheel end faces, said blade shanks having notch-forming surface portions within the edge thereof at said end of the wheel and forming boundaries for portions of said recess means, and means for anchoring said shanks in said slots comprising a ring of welding metal disposed in said recess means where said ring has a weld union with the end face of the wheel, and said ring extending continuously across and through the notches in the edges of the blade shanks where such ring has a weld union with said surface portions of the blade shanks.

EDMUND JEDRZYKOWSKI.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 596,792 Schmidt Jan. 4, 1898 746,061 Fullager Dec. 3, 1903 1,012,749 Sweet Dec. 26, 1911 1,050,187 Westinghouse Jan. 14, 1913 1,149,658 London et a1. Aug. 10, 1915 1,347,031 Guy July 20, 1920 1,398,461 Kerr Nov. 19, 1921 1,440,395 Ljungstrom Jan. 2, 1923 2,255,486 Doran Sept. 9, 1941 2,354,653 Allen Aug. 1. 1944 2,394,124 Warren Feb. 5, 1946 2,405,146 Huber Aug. 6, 1946 2,428,301 Surerus Sept. 30, 1947 FOREIGN PATENTS Number Country Date 675,222 Germany Feb. 9, 1937