US3901309A

US3901309A - Regenerator disk flexible rim

Info

Publication number: US3901309A
Application number: US470533A
Authority: US
Inventors: Glenn W Thebert
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1974-05-16
Filing date: 1974-05-16
Publication date: 1975-08-26
Anticipated expiration: 1992-08-26
Also published as: JPS50160854A; CA1028510A

Abstract

A flexible rim for a regenerator disk is provided by a spirally wound corrugated sheet having the peaks of the ridges of corrugations thereof partly crushed downward toward the hollows of the corrugations along crush paths extending at an angle from one edge of the sheet across the sheet, the wraps of the sheet being bonded together and to the main heat transfer matrix of the regenerator disk. The flexible rim can be used as the rim, per se, of the regenerator disk, or as a connector between the main heat transfer matrix of the regenerator disk and an outer rigid rim thereof.

Description

United States Patent 1191 Thebert Aug. 26, 1975 [5 REGENERATOR DISK FLEXIBLE RIM 75 Inventor: Glenn w. Thebert, Carmel, Ind. Dav,

Attorney, Agent, or F1rmArthur N. Kreln [73] Assignee: General Motors Corporation,

v Detro1t, M1ch. [57] ABSTRACT [22] F1160: May 1974 A flexible rim for a regenerator disk is provided by a [21] Appl. No.2 470,533 spirally wound corrugated sheet having the peaks of the ridges of corrugations thereof partly crushed downward toward the hollows of the corrugations [52] :J.S.CCI l6i/288,dli g/(l)3 along Crush paths extending at an angle from one edge [51] nt. l. 9/ of the Sheet across the sheet, the wraps of the Sheet [58] Field of Search 165/8, 10 being bonded together and to the main heat transfer matrix of the regenerator disk. The flexible rim can be [56] References and used as the rim, per se, of the regenerator disk, or as a UNITED STATES PATENTS connector between the main heat transfer matrix of 2,596,642 5/1952 Bocstad 165/10 X the regenerator disk and an outer rigid rim thereof. 3,511,309 5/1970 Clifford ct a1. 165/10 x 3,534,807 10/1970 Bracken, Jr 165/10 x 6 Clalms, 4 Drawmg Flgul'es REGENERATOR DISK FLEXIBLE RIM This invention relates to a regenerator disk for a rotary regenerator heat exchange apparatus and, in particular, to a flexible rim encircling the main heat transfer matrix core of a regenerator disk.

Rotary regenerators, particularly of the axial flow type as used in gas turbine engines, utilize heat transfer means in the form of a porous metal disk matrix which is rotated so that each element thereof passes successively through two aeriform fluid flow paths, absorbing heat from a hotter fluid and releasing it to a cooler fluid in these flow paths.

Metal matrices ordinarily are made up of crimped or corrugated metal sheets spirally wound into a disk and then brazed or otherwise bonded together so as to provide a rigid cellular or porous structure. This rigid cellular or porous structure is normally enclosed at at least the outer peripheral edges thereof by outer sealing rings or an outer ring which provide a solid rim around the periphery of the matrix.

In regenerators of the type to which this invention is particularly applicable as used in gas turbine engines, the major portion of the disk is heated to relatively high temperatures of the order of up to 1,450F. or higher, whereas the rim or radially outermost portion of the disk is contacted around the perimeter by the relatively cool air and thus is at substantially lower temperature. In addition, the regenerators are also cycled between cool and hot conditions when the engine is started and stopped. Other factors may cause temperature gradients but, in general, whatever the reasons for the differences in temperature between different radial zones of the matrix, the result is differential expansion with attendant overstressing and yielding of the parts and resulting cracking.

The conventional inner core structure or main heat transfer body of such an axial-flow regenerator matrix disk involves alternating flat and corrugated strips or alternating corrugated strips which are spirally wound to form the main heat transfer body of the matrix. One example of such an alternating flat strip and corrugated strip structure is illustrated in U.S. Pat. No. 3,276,515 for Gas Turbine Regenerator issued Oct. 4, 1966 to James H. Whitfield. In a structure of this sort, the matrix is quite rigid once the strips are brazed together. although the corrugated strip can give, the flat strip between the layers of corrugated strip is substantially unyielding. An example of alternating corrugated strips structure is illustrated in U.S. Pat. No. 3,532,157 entitled Regenerator Disk issued Oct. 6, 1970 to William S. Hubble wherein a corrugated or weakened sheet layer is substituted for the flat sheet layer in an attempt to correct the problem encountered in the use of the flat sheet layer.

Using such matrix structures, it is conventional to provide a rim around the matrix disk of the regenerator against which the conventional rim seals of the regenerator will bear. Accordingly, a primary object of this invention is to provide a regenerator disk with a rim which is circumferentially flexible.

It may also be desirable to form a regenerator disk with a rigid outer rim and to provide a suitable connector between this rigid rim and the main heat transfer body of the regenerator disk, the connector being used as a connection between these elements to provide for alignment between the main heat transfer body and the rigid rim and to provide some transmission of torque between these elements. Thus, if the matrix is rotated by a central shaft and the regenerator seals bear against the outer rim, there needs to be a connection between the main body of the matrix and the rim to assure joint rotation of theseparts. In other cases, the connection may be between the heat transfer body or core of the matrix and a rim in the form of a driving gear from which torque is transmitted to rotate the matrix.

A primary object of this invention is to provide a flexible connector rim for use in a rotary regenerator matrix to interconnect the main heat transfer body of the matrix .to a rigid outer rim.

Another object of this invention is to provide a regenerator matrix, the main body of which is formed by spirally wound corrugated strips, one of the strips then being further spirally wound, with the corrugations of the strip partly crushed to provide a flexible interconnection between the main body of the matrix and an outer rim.

A further object of this invention is to provide a flexible rim connection between inner and outer parts, the flexible rim being used to center the parts relative to each other and to provide for transmission of torque therebetween while allowing the parts to conform to each other with low interface loading therebetween.

A still further object of this invention is to provide a regenerator matrix having an inner core of heat transfer material and an outer rim formed by a spirally wound sheet having uniform corrugations, the ridges of which are partly crushed along crush paths, the sheet being wound a sufficient number of turns and secured together and to the inner core to provide an outer rim of the desired radial width, the rim structure providing circumferential flexibility while conforming to the inner core.

These and other objects of the invention are obtained by a flexible rim encircling the main heat transfer body or core of a regenerator matrix, the flexible rim being fabricated as a spirally wrapped, corrugated strip with angled crush paths formed in portions of the peaks of the corrugations of the sheet to prevent nesting of the overlapping layers of the sheet. The flexible rim can be used as the rim, per se, of the matrix, when made a predetermined radial width or as a connection between the main heat transfer body of the regenerator disk and an outer rigid rim.

For a better understanding of the invention, as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings, wherein:

FIG. 1 is an axonometric view of an axial flow regenerator matrix;

FIG. 2 is a detailed sectional view, on an enlarged and exaggerated scale, taken on a radial plane indicated by the line 2-2 in FIG. 1;

FIG. 3 is a sectional view, in exaggerated scale, taken perpendicular to the axis of the matrix as indicated by the line 3-3 in FIG. 2; and,

FIG. 4 is a perspective, enlarged and exaggerated view of the crushed corrugated strip used to form the flexible rim structure of the regenerator matrix.

Referring now to the drawings, there is shown in FIG. 1 an axial flow regenerator matrix 10 which, except for the invention incorporated therein, as will be described, may be of a conventional or known type suited for use in regenerators of the type shown in US. Pat. No. 3,368,611 for Rotary Regenerator Seal with High Pressure Fluid Recovery issued Feb. 13, 1968 to Joseph W. Bracken, Jr., and Richard M. Zeek. Since such a regenerator matrix may be over two feet in diameter with a thickness of only about three inches, it will be apparent that the illustration thereof in FIG. 1 is exaggerated to show the separate elements, to be described, of this structure.

The matrix 1.0, as seen in FIG. 1, includes a cylindrical hub 11 which may include means (not shown) for connecting the hub to a matrix driving shaft, such as disclosed in US. Pat. No. 3,476,173 for Rotary Regenerator Matrix Mount and Drive issued Nov. 4, 1969 to Joseph W. Bracken, Jr., and William S. Hubble. The matrix further includes a cylindrical or diskshaped main body or inner core 12 of heat transfer material which may be defined by alternating flat and corrugated strips or, preferably, by alternating deeply corrugated and shallow corrugated strips of thin sheet metal wrapped spirally around the hub so as to define passages extending generally axially of the matrix through the corrugations. The main heat transfer body of the matrix thus comprises the inner core 12 extending from the hub 11 to a dividing cylindrical surface or boundary 14, indicated by broken line in FIG. 1. The matrix 10 may also include an outer rigid rim, herein shown as a one-piece seal ring 16 with which the rim seals, not shown, of the regenerator cooperate, which extends around the periphery of the inner core 12 of the matrix and is spaced radially from it and connected to it by a flexible rim, generally designated 20, constructed in accordance with the invention, that extends from boundary 14 radially outward, a predetermined radial width.

As best seen with reference to FIGS. 2, 3 and 4, the flexible rim 20 of the regenerator matrix, in accordance with the invention, when used as a connector is formed by at least two spiral coils or wraps of a strip 22 having somewhat triangular shaped, deep corrugations with regular and equally curved ridges and hollows, the corrugations trending axially of the matrix, the peaks of the ridges of the corrugations being crushed as at 22a in relatively narrow, overlapping paths to provide crushed tracks angled at an angle other than a right angle from the edges of the strip and extending there-' across, whereby the crushed tracks will extend across a plurality of corrugations. Preferably, a portion of each peak of a ridge of a corrugation is crushed so that this otherwise peak portion of the corrugation is deformed downward into the valleys or hollows on opposite sides of the ridge to lie substantially in the same plane as the hollows of the corrugations, that is, the plane of the sheet material forming the base or the ho]- lows of the corrugations. It will be seen with reference to FIG, 2 that the angled crushed tracks in the outermost wrap of sheet 22, the upper wrap with reference to this figure, will prevent nesting of the corrugations on the next wrap therein, since a portion of each of the peaks of the corrugations on this next wrap, the lower wrap with reference to FIG. 2, will abut against the crushed portions of the outer wrap. The wraps of the sheet 22 with the angled crushed paths thereon would be secured together as by brazing to each other and to the inner core 12 to form an integral heat exchange matrix structure.

So as to retain the advantages of the corrugated sheet 22, which may, for example, be as little as only three inches wide to correspond to the axial thickness of the regenerator disk, the crushed tracks are relatively nar row and in order to prevent the formation of a continuous circumferential high strength band, each crushed track is angled to extend across only a limited number of corrugations. As best seen in FIG. 4, a crushed track starts at one edge of the sheet and extends at an angle thereacross to run out at the opposite edge, with the next crushed track then partly overlapping circumferentially the first track, but being axially spaced therefrom with reference to the axis of the matrix structure.

The flexible rim 20, as described, could be formed as a separate element and then used to connect two parts, such as the main body of a matrix to an outer rim. However, in the preferred embodiment of a regenerator disk, as shown, the main heat transfer body or inner core 12 thereof is fabricated of alternating turns of a first strip 22 having relatively large corrugations trending axially of the matrix and a second or separator strip 24 having relatively small corrugations trending axially of the matrix. The direction of the corrugations is the same on both strips. However, as will be apparent from FIG. 2, the corrugations on the first strip 22 have ap proximately three times the width and about six times the depth of the corrugations on the second or separator strip 24, these two strips would be spirally wound around the hub 11 to the radial boundary 14 and suitably secured together as by brazing to form an integral inner core. After this, the second or separator sheet 24 is no longer used, but the free end of the first strip 22 with its deep corrugations is then crushed in a suitable manner whereby the strip 22 now forms the strip 22 with its crushed 22a tracks and then this strip 22 is spirally wound a suitable number of turns around the inner core 12 to provide the flexible rim 20, after brazing or otherwise securing the thus wrapped sheet 22 together and to'the inner core 12. The rim 20 will thus provide a low spring rate band which conforms to the inner core 12. The rim 16 can thereafter be connected to the main heat transfer body 12 of the matrix with the rim 20 as the connector therebetween in any suitable manner as, for example, by the use of radial extending pins, not shown, coupling the rim 16 to the rim 20 in the manner disclosed in U.S. Pat. No. 3,534,807 for Regenerator Rim Spacer issued Oct. 20, 1970 to Joseph W. Bracken, Jr., which is incorporated herein by reference.

Although in the embodiment illustrated, the flexible rim 20 is used as a connector between the main heat transfer body or inner core 12 and the outer rigid rim 16, in an alternate embodiment of the invention, not specifically illustrated since it can readily be described with reference to FIG. 1, the outer rim 16 is not used and, instead, the rim 20 is fabricated with sufficient spiral wraps of the sheet 22 with the crushed tracks across its corrugation to form a rim structure of sufficient radial width to provide the rim, per se, of the regenerator disk matrix. That is, the regenerator matrix 10, in this embodiment, would only include the hub 11, inner core 12 and rim 20. Thus, the rim 20, fabricated with the spirally wound, corrugated strip sheet 22 with the curshed 22a tracks thereon, can be used to provide a rim, per se, ofa radial width corresponding, for example, to the radialwidth of the sealing outer rim 16 plus the radial width from boundary 14 to the inner cylindrical edge of outer rim 16, with reference to FIG. 1. For example, using a sheet 22 of stainless steel approximately 0.002 inch thick, with originally uniform corrugations of from 0.060 to 0.130 inch deep (the radial dimension of the corrugations transverse to the general plane of the strip sheet), and with the crushed 22a tracks formed thereon, the sheet 22 could be spirally wrapped a sufficient number of turns and then bonded together and to the inner core 12 to provide, for example, a 0.75 inch radial wide rim with which the rim seals, not shown, of the regenerator would cooperate.

The spiral wraps of sheet 22 of rim 20, whether used as a rim, per se, or as a connector, will provide circumferential (tangential) flexibility and it will readily conform to the inner core 12 with low interface loading. Flexibility of the structure of rim 20 is provided by the geometry of the corrugated strip sheet 22 which permits elastic distortion within the yield strength of the material of sheet 22.

Although the flexible rim 20, of the invention, is shown on the outer pereiphery of an axial flow matrix, it should be relaized that it is applicable to use on a radial flow matrix.

What is claimed is:

l. A rotary regenerator matrix including an annular body of heat transfer material of a structure porous to fluid flow through the body and adapted to receive heat from a fluid flowing through the body, store heat, and to deliver heat to a fluid flowing through the body and, a flexible rim of a spirally wrapped, corrugated sheet encircling said body, the spiral wraps of said corrugated sheet being bonded to each other and to said body, the peaks of the corrugations of said corrugated sheet being crushed in paths angled across a plurality of corrugations and extending from one edge of said corrugated sheet thereacross.

2. A rotary regenerator matrix according to claim 1 further including a rigid rim encircling said flexible rim and connected thereto for rotation therewith, said flexible rim providing a circumferential flexible connection between said body and said rigid rim.

3. A flexible rim on the annular main heat transfer body of a rotary regenerator matrix comprising a corrugated sheet having deep, substantially straight, parallel, regular and curved ridges and hollows, the peaks of said ridges being partially crushed in paths angled across a plurality of corrugations and extending from one edge of said corrugated sheet to the opposite edge of said sheet, said corrugated sheet with said crushed peaks being spirally wound about said main heat transfer body in a plurality of wraps with said wraps of said corrugated sheet being secured together and to said main heat transfer body, said ridges and said hollows of said corrugated sheet extending substantially parallel to the axis of said main heat transfer body.

4. A rotary regenerator matrix structure of annular form porous to flow of fluid generally parallel to the axis of the matrix and effective to block fluid flow circumferentially around the axis, said matrix structure including a first annular section comprising first and second spiral wound strips with each turn of said first strip disposed between adjacent turns of said second strip and with said strips abutting face to face and fixed together into a rigid, elastic structure, said first strips having corrugations trending generally axially of the matrix and with substantial depth radially of said matrix to separate radially the turns of said second strip and define fluid flow passages through said corrugations, said second strip having corrugations parallel to those of said first strip and of relatively small depth compared to those of said first strip and, a second section annular comprising spiral wraps of said first strip, with the peaks of the corrugations of said first strip crushed in paths angled across a plurality of corrugations and extending from one edge of said first strip to the opposite side of said first strip, said first strip with said crushed paths thereon being spirally wrapped at least two turns in abutting face to face relation and fixed together into a rigid, circumferentially flexible rim for said first section.

5. A rotary regenerator matrix structure according to claim 4 further including a rigid rim encircling said second section of said matrix and connected thereto for rotation therewith, said second section of said matrix providing a circumferentially flexible connection between said first section of said matrix and said rigid rim.

6. A rotary regenerator matrix comprising, in combination, an annular body of heat transfer material of structure pervious to fluid flow through the body and adapted to receive heat from a fluid flowing through the body, store heat, and deliver heat to a fluid flowing through the body, a rigid rim extending circumferentially of said body adjacent to but spaced from the outer peripheral surface thereof, and an interconnecting flexible rim coupling said body to said rigid rim and effectivve to transmit torque between said body and said rigid rim, said flexible rim comprising at least two wraps of a corrugated sheet having deep corrugations with a portion of the peaks of said corrugations crushed in angled paths across a plurality of corrugations of the sheet whereby to prevent nesting of the corrugations of one wrap into the corrugations of the next radially outward wrap of said corrugated sheet forming said flexible rim.

UNITED sTATE PATENT AND TRADEMARK OFFICE GERTIFICATE OF CORRECTION PATENTNO. 2 3,901,309

D ED I August 25, 1975 INV,ENTOR(5) 1 Glenn W. Thebert It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1-, line 47, "although" should read Although Column 4- line 63, "cur" should read cru- Column 5, line 21, "pereiphery" should read periphery Column 6, line 18, "section annu lar" should read annular section and,

Column 6, li-ne 44, "effectivve" shoulcl read effective Signed and Scaled this sixth Day of April1976 [SEAL] Attest:

RUTH. C. MASON C. MARSHALL DANN Arresting Officer Commissioner vj'Patents and Trademarks

Claims

1. A rotary regenerator matrix including an annular body of heat transfer material of a structure porous to fluid flow through the body and adapted to receive heat from a fluid flowing through the body, store heat, and to deliver heat to a fluid flowing through the body and, a flexible rim of a spirally wrapped, corrugated sheet encircling said body, the spiral wraps of said corrugated sheet being bonded to each other and to said body, the peaks of the corrugations of said corrugated sheet being crushed in paths angled across a plurality of corrugations and extending from one edge of said corrugated sheet thereacross.