US2281318A - Bladed structure - Google Patents

Description

April 28, 1942. NEUFELD BLADED STRUCTURE Filed Nov. 25, 1940 Inventor. Ja'kob Ne ufeld,

Has Attorney.

Patented Apr. 28, 1942 Jakob N eufeld, Berlin- Spandau,

ration of New York Application November 25, 1940,

Germany, as

signor to General Electric Company, a corpo- Serial lgo. 367,123

In Germany December 9, 193

2 Claims.

The present invention relates to bladed structures comprising a plurality of blades securely fastened to a support. Structure of this type are used in the form of bucket wheels for elastic fluid turbines. More specifically, the invention relates to the type of bladed structures or bucket wheels in which a row of buckets is supported on an undercut groove of a disk or drum. To insert the bases of the buckets into the undercut groove, a portion of the support has to be cut away to form anotch. The last bucket or like element to be inserted and supported in the notch has to be firmly anchored therein.

The object .of my invention is to provide an improved construction and arrangement of bladed structures of the type above specified whereby a firm support of the element located in the notch is assured. This is accomplished in accordance with my invention by the provision of an arrangement in which the element located in the notch is provided with projections extending laterally and radially therefrom for engaging the inner end faces of adjacent elements. 'I'o permit insertion of the notch closing member or block, other elements, preferably spacers between adjacent blades, are made in several parts to permit their insertion subsequent to the insertion of the notch closing element.

For a better understanding 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 front view partly broken away of a bucket wheel for elastic fluid turbines; Fig. 2 is a section along line 2-2 of Fig. 1; Fig. 3 is a top view of Fig. 1; Fig. 4 is a section parallel to the face of the bucket wheel disk; Fig. 5 is a section along line 55 of Fig. 4; Fig. 6 is a section along line 66 of Fig. 4; and Fig. 7 is a perspective view of the notch block of Fig. 1.

The arrangement comprises a support or disk Ill. The disk is machined to form an undercut annular groove H with shoulders l2 on opposite sides of the groove to define supports for buckets connected thereto. A plurality of buckets |3, |4, l5, l6, l7 and I8 are secured to the disk I0. Each bucket has a blade l9 projecting from the support and an undercut base 29 located in the groove H of the disk and engaging the shoulders l2, thus forming in substance a dovetail connection. Adjacent buckets are spaced by spacers 2|, 22, 23, 24, and 26. The bucket spacers are shaped to conform to the bases of the buckets and to engage the shoulders |2 of the support. To permit insertion of the buckets and the spacers, a portion of the shoulders I2 is cut away, thus forming a notch 27 indicated in,

dotted lines in Figs. 2 and 3. One of the spacers or buckets which is finally inserted in the notch has to be firmly anchored to remain in position against centrifugal or other forces acting thereon during operation. In the present example the member finally inserted is the spacer 24.

According to my invention the spacer 24 which broadly constitutes a notch block is provided with an inward projection 28 extending circumferentially to engage the end faces of adjacent members (Fig. 4), in the present instance the end faces of the blades l5 and I6. The projection 28 is oval and located in an oval recess 29 formed in the bottom of the groove I In order topermit insertion of the notch member or spacer 24, the spacers 23 and 25 between bucket blades l4, I5 and I6, I! respectively are made in several parts. Each of the spacers 23, 25, as shown in Fig. 5, comprises two halves 30 and 3| and an intermediate or Wedge member 32. The halves 30, 3| have .outer projections 33, 34 which are turned over to lock the wedge member 32 in position. During assembly the bucket blades and spacers alternately are inserted through the notch 21 and slid along the groove After insertion of the buckets l4 and I! the succeeding buckets l5 and I6 are inserted and slid towards the buckets l4 and I! respectively. Thereupon the notch block or spacer 24 is inserted with the projection 28 located in the recess 29. Upon assembly of the notch block 24 the adjacent buckets 5 and I6 are slid towards the spacer 24. Finally, the spacers 23 and 25 are assembled. To this end the halves 30, 3| are inserted into the groove H and pushed outward in opposite directions into engagement with the shoulders I2. Thereupon the wedge 32 is entered between the halves 30, 3| and. the projections 33, 34 of these halves are turned .over to engage the end face of the wedge 32 and to retain the latter in position.

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

1. Bladed structure comprising a support forming an undercut groove with a notch and a recess in the bottom of the groove adjacent the notch, a plurality of blade and spacer members between the blades having portions engaging and filling the groove, the spacer member filling the notch having an extension located in the recess and engaging the end faces of adjacent members, at least one other spacer member being made in two halves to permit assembly with groove, and a spacer between each pair of adjathe support subsequent to assembly of the spacer cent buckets having an undercut portion engagmember located in the notch, and means locking ing the shoulders and located in the groove, one said halves to the support. of the spacers filling the notch having an exten- 2. Elastic fluid turbine bucket wheel comprission located in the recess and engaging the end ing a disk having an undercut groove forming a faces of adjacent buckets, two other spacers beshoulder with a notch in the shoulder and a reing made in two halves to permit assembly subcess in the bottom of the groove adjacent the sequent to the assembly of the notch spacer, and notch, a plurality of buckets having undercut a wedge locking the two halves to the disk. bases engaging the shoulders and located in the 10 JAKOB NEUFELD.

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