US2986375A

US2986375A - Bladed wheels for compressors, turbines and the like

Info

Publication number: US2986375A
Application number: US640199A
Authority: US
Inventors: Edward A Stalker
Original assignee: Stalker Corp
Current assignee: Stalker Corp
Priority date: 1957-02-14
Filing date: 1957-02-14
Publication date: 1961-05-30
Anticipated expiration: 1978-05-30

Description

y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 1957 3 Sheets-Sheet 1 ATTORNEYS y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 1957 20"'| 33 3 Sheets-Sheet 2 INVENTOR.

EDWARD A. STALKER WMM%@ y 1961 E. A. STALKER 2,986,375

BLADED WHEELS FOR COMPRESSORS, TURBINES AND THE LIKE Filed Feb. 14, 1957 s Sheet-Sheet 3 INVEN TOR.

EDWARD A. STALKER W M, M

ATTORNEYS United States Edward A. Stalker, Bay City, Mich., assignor to The Stalker Corporation, a corporation of Michigan Filed Feb. 14, 1957, Ser. No. 640,199

6 Claims. (Cl. 25339) This invention relates to bladed rotary fluid machines such as compressors and turbines.

An object of the invention is to provide an axial flow bladed wheel in which the blades are integral with a central disk and each blade is connected to said disk in such a manner as to minimize distortion under the action of centrifugal force acting on each blade.

Another object is to reduce the number of brazed joints in such a wheel to a minimum.

Other objects will appear from the description, appended claims and accompanying drawings.

The above objects are accomplished by the means illustrated in the accompanying drawings in which- Fig. 1 is a fragmentary axial section through a rotary fluid machine according to this invention;

Fig. 2 is a fragmentary front view of a bladed wheel of the machine of Fig. 1 including two interdigitating series of blades;

Fig. 3 is an axial view of a central disk and its integral blades;

Fig. 4 is an enlarged fragmentary axial view of a blade and the associated portion of the central disk, before the blade is twisted;

Fig. 5 is a fragmentary radial view of a wheel rim with the blades in section at their root ends;

Fig. 6 is a fragment of a rim and blade on line 6-6 of Fig. 5;

Fig. 7 is a fragmentary axial section of a machine similar to Fig. 1 showing an alternate form of blade neck;

Fig. 8 is an enlarged view of a fragment of a blade disk showing the neck flanges;

Fig. 9 is a section through a blade on line 99 of Fig. 8;

Fig. 10 is a radial view of a fragment of the rotor rim on line 1010 of Fig. 7; and

Fig. 11 is a perspective view of a rotor of Fig. 7 partly cut away to show the interdigitation of the blades.

In US. Patent No. 2,613,910, issued October 14, 1952 to the present inventor there is disclosed a sheet metal construction for bladed wheels wherein each blade is integral with -a central disk. The neck connecting each blade to the central disk is twisted to place the root end of each blade at the proper angle with respect to the plane of the disk.

In the present invention a series of wheels are assembledgas shown in Fig. 1, each wheel including a pair of central disks with necks joining the individual blades. Each neck is formed between dies so that each radially extending element of the neck is a straight line along itsextent from the perimeter of the disk to the root secatent f) the wheel. Means are also disclosed for providing substantial fillets at the root sections of the blades.

The wheel comprises the sets of

blades

20 and 22, integral respectively with

central disks

24 and 26 of the hub means 28, the two sets being assembled face to face with the blades interdigitating to form the wheel as shown in Figs. 1 and 2. The blades 20 are connected to their disk 24 by the

necks

30 and 34 extending from the periphery 31 of the

central disks

24 and 26 to the root sections 32 of the blades. These sections are at about the radial level of the rim 33. Blades 22 are connected in like manner by the necks 34 to their disks 26.

The necks 30' and 34 are formed on dies to have straight elements extending from the central disk to the root ends of the blades. That is, each neck may be considered as comprised of a series of straight line side-byside elements represented by the series of dotted lines 3'5-42, Fig. 4, each of which extends from the perimeter 31 of the central disk to the root of its respective blade in a straight line. Then each element of the neck can carry its portions of the centrifugal load of the blade without elongation from a bow in the element. Were such elements bowed along their length the blade would move outward as the centrifugal load removed the bow.

The wheel hub means 28 comprises the

central disks

24 and 26 and a rim means 33 which is comprised of the two

rings

66 and 68 each of which has an integral flange '69, 70 which together define the hub rim extending between blades and from front to rear thereof. It also includes the fillet elements 71 and 72, Figs. 5 and 6.

The rings have registering notches and 82, Fig. 5, which in registration define blade openings through which the blades extend in the general radial direction. Each opening is preferably larger than the cross section of the root end of the blade so that the fillet elements 71, 72 can be inserted on each side of the root end of the blade. These fillet elements may be solid, preferably being made of sintered metal powder, such as stainless steel or nickel for instance, so that they will absorb braze material during a brazing operation and become essentially solid and bonded to the blades and rims, and preformed as shown in Fig. 6 providing fillets which fay the side surfaces of the blades and the exterior surface of the rim. Such powder material after being impregnated provides a high damping effect against the vibration of the blades. The side legs of the rim means are secured to the central disks preferably by braze material.

The rim prevents the blades from turning or untwisting under the action of centrifugal force and since straight line elements connect the root sections of the blades to the disks the tips of the blades are stabilized at a selected radius.

The blades may have any desired cross section impressed upon them. Fig. 5 shows cambered blade sec tions whose central portions have parallel sides and faired nose and tail portions.

Fluid flows through the passages between the blades extending from the front of the wheel to the back thereof in the downstream direction. The leading edges are at the front of the wheel, i.e. at the right hand edge as shown in Fig. 5.

In another form of'the invention shown in Figs. 7-11, a

neck flange

104, 106 is formed along each side of a neck extending from one neck to the adjacent one. Each

neck

107, 108 preferably comprises straight line elements as in Fig. 4. The neck flanges add greatly to the stiffness of each neck along their general radial extent and precludes a tendency for the blades to move outward from changes in shape of the necks.

The neck flanges 104 of the rear central disk 26 extend rearward and those (106) of the front central disk 24 extend forward. See Figs. 7 and 11. This facilitates placing the central disks close together preferably in contact with annular spacers 110 as shown. The necks connect the blades 112 and 114 to their respective disks. The blades may also have blade sections varying in thickness along the greater parts of their chord lengths.

The rotors are fixed between the end disks 120 and the cylindrical spacers 122 by the tie rods 124.

While the invention has been described as embodied in a compressor wheel it can be incorporated in like manner in turbine wheels.

It will now be clear that there has been provided a novel bladed wheel wherein the blade is integral with a central disk and has a twisted portion or neck joining the blade to the disk. The neck is made to be a strong structural member by imparting the necessary twist therein by dies so that there is no how along radial lines in elements extending from the disk to the roots of the blades, the elements all being straight. Thus each neck is so formed over a major part of its width that lines extending on the surface thereof from the disk to the root section in the general radial direction are essentially straight lines. This configuration eliminates any significant displacement of the blade radially due to centrifugal force straightening out bowed elements.

While the forms of apparatus herein described con stitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing. from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In combination in an axial flow wheel for compressors, turbines and the like having an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout and extending radially outward thereof each said blade having a root section connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said necks being twisted to position said root sections of each said blade at a substantial angle with respect to said disk, each said neck tending to untwist during said rotation, and rim means positioned at said root sections extending from front to rear of said blades and therebetween, said rim means fitting closely to said blade root ends restraining said necks from untwisting, each said neck being so formed over a major part of its width that lines extending on the surface thereof from said disk to said root section in the general radial direction are essentially straight lines establishing substantially constant tip diameters for said blades during said high speed rotation.

2. In combination in an axial flow wheel for compressors, turbines and the like having an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout and extending radially outward thereof each said blade having a root section connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said wheel being adapted for high speeds of rotation with accompanying flow of said fluid in a generally axial direction, said necks being twisted to position said root sections of each said blade at a substantial angle with respect to said disk, each said neck tending to untwist during said operation, rim means positioned at said root sections extending from front to rear of said wheel and therebetwecn, said rim means fitting closely to said blade root ends restraining said necks from untwisting, each said neck being so formed over a major part of its width that lines extending on the surface thereof from said disk to said root section in the general radial direction are essentially straight lines, and flanges at each side of said necks extending from said root section substantially to said disk establishing substantially constant tip diameters for said blades during said operation at said high speeds of rotation.

3. In combination in an axial flow wheel for compressors, turbines and the like having an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout and extending radially outward thereof each said blade having a root section connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said wheel being adapted for operation at high speeds of rotation with accompanying flow of said fluid in a generally axial direction, said necks being twisted to position said root sections of each said blade at a substantial angle with respect to said disk, each said neck tending to untwist during said operation, rim means positioned at said rotor sections extending from front to rear of said wheel and therebetween, said rim means fitting closely to said blade root ends restraining said necks from untwisting, each said neck elements being so formed over a major part of its width that lines extending on the surface thereof from said disk to said root section in .the general radial direction are essentially straight lines, and flanges at each side of said necks each extending continuously from said root section of a said blade radially inward along the perimeter of said plate and radially outward along the adjacent said neck establishing sub stantially constant tip diameters for said blades during said operation at said high speeds of rotation.

4. In combination in an axial flow wheel for compressors, turbines and the like having an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout each connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said blades having blade surfaces and root sections for operation at high tip speeds with accompanying flow of said fluid in a generally axial direction, said necks being twisted to position said root sections of each said blade at a substantial angle with respect to said disk, each said neck tending to untwist during said operation, and rim means positioned at said root sections extending from front to rear of said wheel and therebetween, said rim means fitting closely to said blade root ends restraining said necks from untwisting, each said neck being so formed over a major part of its width that lines extending on the surface thereof from said disk to said root section in the general radial direction are essentially straight lines.

5. In combination in an axial flow wheel for compressors, turbines and the like having an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout each connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said blades having blade surfaces and root sections for operation at high tip speeds with accompanying flow of said fiuid in a generally axial direction, each said neck being twisted to position each said root section of each said blade .at a substantial angle with respect to said disk, each said neck tending to untwist during said operation, rim means positioned at said root sections extending from front to rear of said wheel, each said neck being so formed over a major part of its width that lines extending on the surface thereof from said disk to said root section in the general radial direction are essentially straight lines, and flanges at each side of said necks extending from said root sections substantially to said disk establishing substantially constant tip diameters for said blades during said operation at said high tip speeds.

6. In combination in an axial flow wheel for compressors, turbines and the like defining an axis of rotation, a blade disk having a plurality of blades peripherally spaced thereabout each connected to said disk by a neck, said blades, said necks and said disk being formed integrally from a single piece of sheet metal, said blades having blade surfaces and root sections for operation at high tip speeds with accompanying flow of said fluid in a generally axial direction, said necks being twisted to root sections substantially to said disk establishing subposition said root sections of each said blade at a substantially constant tip diameters for said blades during stantial angle with respect to said disk, each said neck said operation at said high tip speeds.

tending to untwist during said operation, rim means positioned at said root sections extending from front to rear 5 R fer nc Cit d i the fil f hi patent of said wheel, each said neck being so formed over a UNITED STATES PATENTS major part of its width that lines extending on the surface thereof from said disk to said root section in the 1 3- Stalk 1953 general radial direction are essentially straight lines, and 2,678,537 Stalker May 13,

flanges at each side of said necks extending from said 10 2,801,071 'P July 30, 1957