US3638716A

US3638716A - Regenerator seal

Info

Publication number: US3638716A
Application number: US879729A
Authority: US
Inventors: Jack P Hart
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1969-11-25
Filing date: 1969-11-25
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01
Also published as: GB1267780A; FR2068631B1; FR2068631A1

Abstract

A rotary regenerator of the drum-matrix-type. The regenerator matrix is located and supported by two parallel rollers engaging the matrix rims at the inner or hot face of the matrix adjacent the bulkhead. The main seals are pivoted adjacent the drive rollers so that they can rotate to align with the matrix notwithstanding expansion and distortion. The angular position of the main seals is determined by aligning rollers engaging the outer or cold face of the matrix and mounted on the main seal frame. These are biased into engagement with the matrix by springs. The particular subject matter is improved structure of the main seals including the frame, roller mounts, cooling provisions, side seals, the secondary seal, and connection of the frame to the regenerator bulkhead.

Description

{mite Hart States atet [54] REGENERATOR SEAL [72] Inventor: Jack P. Hart, l-linsdale, lll.

[73] Assignee: General Motors Corporation, Detroit,

Mich.

[22] Filed: Nov. 25, 1969 [21] App]. No.: 879,729

[52] 11.8. Cl ..165/9, 165/10 [51] Int. Cl ..F28d 19/04 [58] Field of Search ..165/9, 10

[56] References Cited UNITED STATES PATENTS 3,384,156 5/1968 Addie ..l65/9 X 2,888,248 5/1959 Bubniak et al... .....l65/9 3,298,429 1/1967 Bubniak ..l65/9 Feb. l, 1972 Primary ExaminerAlbert W. Davis, Jr. AttarneyPaul Fitzpatrick and Jean L. Carpenter [5 7] ABSTRACT A rotary regenerator of the drum-matrix-type. The regenerator matrix is located and supported by two parallel rollers engaging the matrix rims at the inner or hot face of the matrix adjacent the bulkhead. The main seals are pivoted adjacent the drive rollers so that they can rotate to align with the matrix notwithstanding expansion and distortion. The angular position of the main seals is determined by aligning rollers engaging the outer or cold face of the matrix and mounted on the main seal frame. These are biased into engagement with the matrix by springs. The particular subject matter is improved structure of the main seals including the frame, roller mounts, cooling provisions, side seals, the secondary seal, and connection of the frame to the regenerator bulkhead.

3 Claims, 13 Drawing Figures fi lll luu l! y ii 1/,

1/ a; w M #7 If PATENTEU as 11972 3.638.716

SHEET 1 OF 5 A TTO/P/VEY PATENTEU FEB 1 s72 SHEET 2 OF 5 A T TO/QNEY PATENTED FEB H972 3.I638 .7l6

sum .3 or 5 I N VEN TOR A TTOPNEY PATENTEU FEB 1 i972 SHEET 5 OF 5 INVENTOR. (/25? #97 E llllll m @T MW YWHHHHM BY M A TTOQNEY REGENERATOR SEAL INTRODUCTION My invention relates to regenerators, by which I mean heat exchange devices of the sort in which a heat retaining mass is rotated so as to move alternately through the flow paths of two fluids so as to absorb heat from the hotter fluid and release it to the cooler. In some respects, it is particularly concerned with a regenerator having a drum matrix in which flow takes place radially through an annular drum, and with one suited to a gas turbine type of installation. The installation in a gas turbine involves substantial pressure differences between the two fluids, with attendant problems in supporting the matrix and sealing against leakage from high to low pressure. It also involves high temperatures.

The regenerator structure which is the subject of this application is intended for the large regenerative gas turbine engine described in Dixon et al. U.S. Pat. No. 3,455,107 for Gas Turbine Engine, July 15, 1969. My invention is particularly directed to improvements in a main seal for such a regenerator disclosed in Addie U.S. Pat. No. 3,384,156 for Rotary Regenerator, May 21, I968.

The principal objects of my invention are to improve the reliability and durability of regenerators; to provide a regenerator structure particularly adapted for gas turbine service; to provide a regenerator having improved means for supporting and driving the matrix particularly adapted to horizontal axis matrices of large size; to provide improved structure ofa main seal and its supports; to increase sealing efficiency; to reduce manufacturing costs; to facilitate assembly; to improve resistance to high-temperature gases; to accommodate relative thermal expansion of the parts; and to provide improved lubricating, sealing, and cooling structure for regenerator driving and locating arrangements.

Various ones or all of these objects may be realized, depending upon the particular installation and the characteristics of a particular design according to my invention, but the seal structure as a whole is particularly suited to realize the various objects in the locomotive turbine environment for which it is primarily intended.

The nature of my invention and the advantages thereof will be apparent to those skilled in the art from the succeeding detailed description of the preferred embodiment of the invention and the accompanying drawings thereof.

FIG. I is a somewhat schematic side view, with parts cut away, ofa regenerative gas turbine arrangement.

FIG. 2 is a sectional side view of the upper main seal and adjacent structures taken on the plane indicated by the line 2-2 in FIG. 3.

FIG. 3 is a sectional view taken on a plane substantially containing the axes of the matrix and of a set of supporting and driving rollers.

FIG. 4 is a sectional view taken substantially on the plane indicated by the line 4-4 in FIG. 2.

FIG. 5 is a sectional view taken on the the line 5-5 in FIG. 3.

FIG. 6 is a partial elevation view taken on the plane indicated by the line 6-6 in FIG. 3.

FIG. 7 is a fragmentary sectional view taken on the plane indicated by the line 7-7 in FIG. 6.

FIG. 8 is a sectional view of the seal housing taken on the plane indicated by the line 3-8 in FIG. 3.

FIG. 9 is a sectional view of bypass seal structure taken on the plane indicated by the line 9-9 in FIG. 2.

FIG. 10 is a partial view of a seal bar taken on the plane indicated by the line 10-10 in FIG. 2.

FIG. 11 is a cross section ofa main seal support taken on the planes indicated by the line 11-11 in FIG. 12.

FIG. 12 is an elevation view of the main seal support, with parts cut away and in section.

FIG. 13 is a plan view ofthe same.

Referring first to FIG. 1, which illustrates in a general or schematic way the structure of the regenerator as part of the plane indicated by gas turbine engine referred to above, a gas turbine engine includes a turbine 13 which drives a compressor 14 through a shaft 15 and also drives a power output shaft 17. The compressor supplies air to a regenerator 18 which comprises a regenerator case 19 and at least one drum-shaped regenerator matrix 21; preferably, two matrices rotating about the same horizontal axis 22 perpendicular to the axis of the turbine. The matrices are disposed generally side by side with the turbine partially within the matrices and enclosed within the regenera tor case. A bulkhead 23 and associated structure divides the interior of the regenerator case between a high-pressure chamber 25 into which the compressor discharges and a lowpressure chamber 26 into which the turbine discharges. Main support and seal assemblies 27 are mounted in the bulkhead at the places where each drum passes through the bulkhead as it is slowly rotated about the axis 22. Air compressed by the compressor flows radially inwardly through the forward roughly sector of the matrix, through combustion apparatus (not illustrated) and through turbine 13 to chamber 26 at the rear side of the bulkhead, where the turbine exhaust flows radially outward through the rear sector of the matrix to an exhaust stack 28.

REGENERATOR FIG. 1 illustrates schematically the right-hand regenerator ofthe engine, the left-hand one being simply a mirror image of the right-hand one, and the upper and lower halves of each regenerator being substantially mirror images of each other except for differences relating to oil supply and return and to the provision of a power input into one of the seal assemblies to rotate the matrix. For background to my invention, we may consider the regenerator case 19 to comprise a radially outer wall 30 broken by the entrance from the compressor 14 and by the exhaust stack 28; a rear wall 31; and a front wall principally defined by a cover plate 32, which bolts to the remainder of the regenerator case.

The matrix 21 is supported and located primarily by a drive roller 34 mounted within the upper main seal assembly 27 and by an idler roller 35 mounted within the lower main seal and support assembly 27, the radially inner face of the matrix being in engagement with these rollers to locate, support, and rotate the matrix. The assemblies 27 also include biasing or aligning rollers 37 which bear against the radially outer face of the matrix. The matrix is located along its axis of rotation by structure ofthe main seals at 27, to be described, and by locat ing rollers 38 mounted on the front and rear walls of the case and engaging the edges ofthe matrix.

The matrix 21 is shown only generally in the drawings as including rims 39 which are joined by spacers (not illustrated) and between which is located porous heat transfer material 41) which may be in the form of stacked corrugated plates of thin sheet metal. Suitable matrix structures are shown in considerable detail in Addie and Hart U.S. Pat. Nos. 3,367.405 and 3,435,888 and Hart and Tharp U.S. Pat. No. 3,456,717. For the present, it is sufficient to consider the matrix as being a rigid drum of which substantially all except the rim portions is porous to flow in the direction radially of the matrix.

MAIN SEAL ASSEMBLY As previously stated, the function of the main support and seal assemblies 27, in addition to locating and driving the matrix is to prevent, as far as feasible, leakage of the highpressure compressor discharge air from the chamber 25 into the chamber 26. Each thus defines a frame through which the matrix passes and which is in sealing contact with the inner and outer faces of the matrix and with the edges of the matrix, which are the sides of the rims. The main seal includes a seal frame 42 (FIGS. 2 and 3) which is fixed to the

walls

31 and 32 of the regenerator case and to the bulkhead 23. This seal frame includes a rear end plate 43 which includes a slightly tapered circular boss 44 that projects through an opening in the rear wall 31. Plate 43 is secured to the rear wall by capscrews 46. The frame also includes a front end plate 47 including a boss 48 which projects through a circular opening in the front wall 32. This is secured to the front wall by capscrews 46. The seal frame 42 also includes three generally parallel struts or spacers which are fixed to the two end plates. These are an upper support 50 which bolts to the bulkhead 23, a lower support 51 which likewise bolts to the bulkhead, and a crossbar or tie bolt 52, the ends of which are bolted to the plates 43 and 47. The seal frame thus constitutes an open framework fixed to the regenerator case and bulkhead.

Within this frame a seal housing which encloses the

rollers

34 and 37 or 35 and 37, as the case may be. is mounted with slight freedom for tilting movement, generally as described in U.S. Pat. No. 3,384,156, so that the seal structure accommodates itself to changes in diameter of the matrix with temperature and so that the matrix is positively impinged between the opposed rollers on opposite faces of the matrix. The regenerator housing includes parts which seal against the matrix, this being called the primary seal. There is a secondary seal between the matrix housing or primary seal and the seal frame with respect to which it is slightly movable.

The seal housing 54 (see primarily FIGS. 2, 3, 4, 5, and 8) includes a cool face seal bar 55 extending across the outer face of the matrix, a but face seal bar 56 extending across the inner face of the matrix and two sideplates 58 which are slightly flexible plates of lnconel (trademark) which are fixed to and join together the seal bars. The assembly of these four parts thus provides a frame around the matrix 21. The seal housing 54 is mounted for slight tilting movement around an axis parallel to the axis of rotation of the matrix and the rollers by a pivot arm 59 (FIGS. 4 and 8) at each end of the housing, these pivot arms being secured by bolts 60 which pass through the sideplate 58 and into the end of the cool side seal bar 55.

The seal housing swings on pivots defined by a cylindrical boss 62 extending outward from each pivot arm.

Each boss 62 is supported by a spherical bearing 63 in a recess machined in the inner surface of the end plate 47 or 43. The spherical bearings allow for some minor dislocations of the supports for this sea] housing assembly. At the rear plate 43, the recess for the spherical bearing is closed by a plate 64. At the outer wall, an oil manifold 66 (see also FIG. 6) bolted onto the boss 48 and a circular cover plate 67 cover these spherical bearings and provide an inlet for oil. The description of the lubrication system of the seal will be deferred.

The cold side seal bar 55 is of roughly rectangular cross section, as shown most clearly in FIG. 5. The hot side seal bar 56 is split in a plane generally parallel to the surface of the matrix at 72 and includes a cover 68 held to the portion 56 and the upper edge of sideplates 58 by bolts 70. The portions 56 and 68 of the hot side seal bar define between them a chamber 71 of generally circular cross section within which is mounted the roller means 35. The sideplates 58 terminate at the split line 72 between the two parts of the hot side seal bar and the portion 56 of the seal bar is fixed to the sideplate by bolts 70 and 7d.

One of the features of the seal housing 54 is the adaptation to differential expansion of the cold side seal bar 55 and hot side seal bar 56. Since these, in the particular example are of considerable length, over 2 feet, and there is a great difference in their temperatures when the engine is operating, there is a differential expansion of about 0.16 inch between the hot and cold conditions. To accommodate this, the hot side seal bar is made about 0.l2 inch shorter than the cold side seal bar and this difference in length, as well as the accommodation to relative expansion is taken care of by flexure of the lnconel sideplates 58. These are each distorted approximately 0.06 inch toward each other at seal bar 56 in the cold condition and warped approximately 0.02 inch away from each other when hot, this making up the total relative expansion of 0.16 inch. By this structure, any such arrangements as sliding parts are superseded and the structure is considerably simplified over what would be required for other arrangements such as sliding parts or double walls to accommodate the expansion and preserve the sealing function.

MATRIX-ENGAGING ROLLERS The chamber 71 within the hot side seal bar 56 provides an enclosure for the roller means 35 in the lower seal assembly 27, which is illustrated in the figures. This roller means includes a hollow shaft 75, the ends of which are supported in spherical roller bearings 76, one of which is axially fixed in the front end plate 47 between the oil manifold 66 and a retainer 78 bolted to the inner side of plate 47. The bearing 76 at the rear wall 31 is mounted, with clearance for some sliding move ment to accommodate relative thermal growth, between retainer 78 and an oil drain cover plate 79, these being bolted to the rear end plate 43. The retainer 78 bears piston ring seals 80 which bear against the cylindrical inner periphery 82 of the ends of the portions 56 and 68 of the hot side seal bar. These piston ring seals prevent leakage to or from the cavity 7! and are radially yielding to permit slight relative motion of the seal housing 54 with respect to the shaft 75.

The hot side matrix roller means 35 includes two rollers 83 preferably of the contour illustrated clearly in F IG. 3. These rollers are pressed onto the somewhat reduced end portions of shaft 75 and are positively coupled to the shaft by face splines at 84. The outer ends of the rollers 83 bear piston ring seas 86 which coact with the inner surface of retainer 78. The bearings 76 abut the outer ends of the rollers 83 and are retained on the shaft respectively by a bolted-on plate 87 and by an oil inlet adapter 88. This mounting of the roller means 35 carries the load exerted on the shaft 75 by the matrix directly to the bearings '76 outboard of the matrix and generally in alignment with the plane of

walls

31 and 32. The bearings being thus located outboard are farther from the extremely hot matrix than would otherwise be the case, which is desirable from the standpoint of endurance of the hearings. Note that these spherical bearings also allow for some wracking or distortion of the structure by which the shaft 75 is supported without unduly loading or harming the bearings.

The shaft '75 and rollers 83 are further protected from heat radiated from the matrix by an insulating jacket defined by thermal insulating material retained by a thin sheet metal shell or facing. The insulating material at 90 on the faces of the rollers is retained by rivets 91 and the insulating material at 92 which covers the shaft 75 between the rollers is retained by a thin sheet metal cover, the ends of which abut the covers of the insulation 90.

The oil inlet adapter 88 which is bolted to the shaft 75 has on its outer periphery gear teeth 94 which are provided for the purpose of driving a matrix rotation sensor (not illustrated) of the type disclosed in US. Pat. No. 3,537,258.

Proceeding now to the arrangement of the cold side roller means 37 which is directly supported on the cold side seal bar 55; the roller 37 is mounted within an annular recess in the end of the seal bar and is supported both by a radial needletype bearing and by a ball thrust bearing, the former taking the radial loads and the ball bearing the axial loads. The inner race of ball bearing 95 is held by a washer and nut 96 on a stub shaft 97 projecting into a recess 98 in the seal bar from the roller 37. The outer race of bearing 95 is held against the shoulder of recess 98 by a retainer ring 100 bolted to the seal bar. The radial bearing 102 has an inner race held in place against a shoulder within recess 98 by a bolted-on cap i103, and the outer race of the radial bearing is retained by a second bolted-on cap 104. This structure provides for ready installation, removal, and service of the rollers or the bearings for them. Piston ring seals 106 prevent leakage of oil to the exterior of the seal bar.

Since the housing 54 on which rollers 37 are mounted can swing about the pivots 62, the rollers can be pressed against the outer surface of the matrix rim 39 and are so pressed by a biasing device 107 including a plunger 108 which bears against a boss 109 on the cool side seal bar 55. The biasing device will not be further described herein but is fully explained in the above-mentioned U.S. Pat. No. 3,384,156. The hot side roller means 34 of the upper seal assembly is similar to that described but is positively rotated through a quill shaft PRIMARY SEAL This leads to a description of the primary seal arrangements for minimizing leakage of air through the interior of seal housing 54 from high pressure to low pressure. In the structure of this seal, the seal bars 55 and 56 coact directly with the matrix, without any removable shoes or facings. Thus, the hot side seal bar 56 has a convex sealing surface 110 (FIGS. 2 and 5) and the cool side seal bar 55 has a slightly concave surface 111 immediately adjacent the matrix 21. These surfaces lie immediately adjacent to labyrinth seal strips (not shown) in the matrix and cooperate with them in known manner.

The cool side seal also includes a guide strip to cooperate with rubbing strips on the matrix labyrinth seal bars as disclosed in U.S. Pat. No. 3,367,405. The structure and mounting of the guide strip in my seal is improved over that of the patent. As shown most clearly in FIGS. 3 and 5, a guide strip 112 is mounted in a slot 113 in the seal bar 55. It comprises a wear strip 114 of hard material such as a cemented carbide. The strip is mounted in a holder defined by a carrier 115 and two angle section pieces 116 bolted to the carrier 115 and which bear against a flange on the wear strip 114. It will be seen that this carrier structure reinforces and protects the carbide strip, which is relatively brittle. A spacer 118 lies between the carrier 115 and the bottom of slot 113. The spacer and carrier are retained in place by two long capscrews 119 which extend through bores in the hot side seal bar and through holes in the spacer 118 into threaded holes in the carrier 115. The spacer 118 may be removed to provide clearance for the thicker end of the guide strip to be removed in the event of need for repair or replacement. Also, the spacer 118 may act as a shim and by selective assembly be used to correct the clearance between the guide strip and the thickness of the matrix. The wear strip is located between a lug 117 on the seal bar and a cap 121 bolted to the carrier 115.

To minimize leakage along the edges of the matrix; that is, the outer faces of the matrix rims, two side shoes mounted on the inner surface of a sideplate 58 are biased against each edge of the matrix. Referring to FIGS. 3, 4, 8, and 10, two generally rectangular side shoes in the form of metal plates 120 are located in a recess 122 in each sideplate 58. These shoes closely approach each other at their adjacent edges. At their remote edges, each plate has two tangs 123 (FIG. 8) which are received in a slot 124 extending from the corner of the recess 122. The engagement of these tangs in the slots holds the side shoes against the edge of the recess 122 and holds them against the force tending to move them with the matrix due to friction between the shoe and the face of the matrix rim. Each shoe 120 is biased into sliding contact with the matrix by a spring assembly 126 fixed to the outer surface of sideplate 58.

Each spring assembly includes a cylinder 127 threaded into the plate 58, a plunger 128 extending through the plate into contact with the center of the side shoe 120, a compression spring 130, and an abutment 131 threaded in the cylinder 127. A thin deformable lock plate holds the cylinders 127 against unscrewing from the plate 58. Note cylinder 127 is closed by the abutment 131 so that there is no leakage from within the recess 122 to the exterior of plate 58 from which it could bleed to low pressure. Also, the springs 130 are protected to a considerable extent from the heat of the matrix. With the arrangement of side shoes described, the assembly is suitable for movement of the matrix in either direction and the four side shoe assemblies may all be the same.

Since it is contemplated that the regenerator will be used in a locomotive in which case there may be substantial shock loads on the engine in traversing rough track, the seal assemblies 27 include bumper stops which protect the side shoes 120 against possible heavy loads from a shifting matrix. Referring to FIG. 4, a bumper stop 132 is mounted on the end plate 43 and the end plate 47 adjacent the margin of the

boss

44 or 48. Each bumper stop includes a head 134 and a hollow stem 135, the stem being swivel mounted in a spherical bearing 136 retained in a recess in the plate by a snapring and held on the stem by a snapring 139. A captive compression spring 138 biases the bumper stop to lie perpendicular to the plate, but it can swivel slightly to accommodate to slight coning ofthe rim.

If the stop is engaged by the matrix rim, it stops movement of 7 the rim toward the end plate before the side shoes bottom in the recesses 122.

BYPASS AND ROLLER CAVITY SEALS The regenerator includes bypass seals at each rim of the matrix which seal between the matrix and the front and rear walls of the regenerator case. These seals preferably are of the type described in McCreary U.S. Pat. No. 3,360,275. The bypass seals are interrupted at the main or bulkhead seal assemblies 27 and some provision needs to be made in the main seal to prevent flow of gas past the outer edge of the matrix. Ends of the bypass seal 140 at the main seal are illustrated in FIG. 2. A short bypass seal segment 142 (FIGS. 2 and 9) mounts on each of the rear and front end plates 43 and 47. This is put in place after the seal is installed in the frame 42 and the frame into the regenerator. An angle bracket 143 is bolted to the wall 43 or 47. A seal retainer 144 is bolted to the angle bracket. The seal retainer 144 may be adjusted both radially and axially of the matrix by adjustment of the bolts in the holes through which they pass in the angle bracket and seal retainer. A seal block 146 caged within the seal retainer is biased into contact with the inner surface of the matrix rim by leaf springs 147. The seal block is trapped in the direction circumferentially of the matrix by a channel-shaped member 148 held by screws 149.

Bypass seals are also provided on the hot side seal (see FIGS. 3 and 10). Referring to FIG. 10, an opening 150 in the hot side seal bar 56 provides foraccess of the roller 83 to the matrix rim. Two L-shaped cavity shoes 151 float in cor responding L-shaped slots cut in the inner face 110 of the seal bar. These are biased into engagement with the inner surface of the matrix rim by compression spring 152 trapped in recesses in the seal bar. Between the L-shaped cavity shoes 151 and each edge of the seal bar, floating shoes 154 are mounted in slots cut in the seal assembly. These are biased into contact with the matrix by trapped compression springs 155.

MAIN SEAL MOUNTING AND SECONDARY SEALS We may now consider the arrangement by which the seal frame 42 is mounted on the bulkhead 23, and also the secon dary seals which seal between the seal frame 42 and the seal housing 54 which are capable of slight relative movement.

As pointed out previously, the seal frame 42 includes an upper (hot side) support 50 and a lower (cool side) support 51, these being fixed to the end plates 43 and 47, and being fixed to the bulkhead 23 when the seal frame is assembled into the regenerator. The supports form a part of the arrangement by which the secondary seal is mounted as will be seen. Structurally, the support 51 is quite simple, as there is no great temperature problem on the cool side. For this reason, only the upper support 50 will be described in detail.

The seal support which is on the inside of the matrix, which is the upper support in the lower seal and support assembly described here, faces severe temperature problems. It is exposed to hot exhaust gas from the turbine and to radiation from the engine combustion chambers. Also, the seal bar to which it is connected is in contact with the surface of the matrix which is quite hot. The seal support is bolted to the regenerator bulkhead which acts as a heat sink and which is cooled to some extent by the compressor discharge air which flows in contact with the face of the bulkhead, and is thus substantially cooler than the seal.

It is, of course, quite important that the whole arrangement be as nearly as possible airtight to minimize leakage of the compressed air to the engine exhaust.

Referring now generally to FIG. 2 and particularly to F IGS. 1 1, 12, and 13, the upper seal support 50 is an assembly which makes provision for relative thermal expansion between the seal frame 42 and the bulkhead 23 to which it is fixed. It includes a straight support bar which has integral with it at each end a head 158. Tapped holes 159 in the rear face of the support bar receive bolts which pass through the bulkhead and fix it to the bulkhead, such bolts (for the lower Support) being indicated at 160 in FIG. 2. Bolts 161 pass through the end plates 43 and 47 and into tapped holes in the outer surface of the heads 158 to fix the seal frame to the bulkhead.

A seal bar 162 is mounted on the support bar 156 by an arrangement which centers it in the direction axially of the matrix while allowing relative expansion between the

parts

156 and 162. Bar 156 has a horizontally projecting flange 163 which is divided into sections by a number of expansion slots 164. This compensates for the fact that the flange is more highly heated than the body of the bar. The rear edge of bar 162 is slotted to provide an upper flange 166 and a lower flange 167 which fit over and under the flange 163 of the support bar. There is, thus, a tongue and groove connection between these two parts. The seal bar is fixedly located with respect to the support bar at the midpoint by a dowel 168 which is a close fit in reamed bores in the

flanges

166, 163, and 167. Additional locating pins 170 disposed along the structure between pin 168 and each head 158 are fitted in holes in the flange 163 but are in holes 171 elongated axially of the matrix in the

flanges

166 and 167 so that relative expansion of the support bar and seal bar are permitted.

Capscrews 172 which pass with clearance through holes in

flanges

166 and 163 are threaded into holes in the flange 167. These hold

flanges

166 and 167 together so that they bear against the flange 163 to limit a leakage path around the flange 163. These flanges also close off in great part the leakage path defined by the slots 164 in the support bar 156.

A filler strip 174 is mounted below flange 163 and retained in part by an abutment 175 on the support bar. This also serves to block off the slots 164. The filler strip 174 is ultimately retained in place on the support bar by a secondary seal retainer 176 (FIG. 2) which is bolted to the underside of support bar 156. The filler strip 174 is in two sections aligned end to end with a small gap between them at the middle, and each section is located in the direction axially of the matrix by a pin 177 at one end. The pin holds the end of the filler strip adjacent head 158 closely against the end of the slot.

When the engine is assembled, the forward face of the bulk head is lagged or insulated to reduce heat transfer to the bulkhead from the compressed gas and combustion apparatus. Also, the forward face of the support bar 156 is covered with insulation. Thus, the temperature of the main body of the support bar, exclusive of the flange 163, and of the bulkhead is determined largely by the exhaust temperature. The seal bar 162 becomes considerably hotter but, as pointed out, this may expand relative to the support bar without departing from its location which is fixed by the pin 168.

The slots 164 in flange 163 allow it to expand without distorting the structure or setting up undesirable stresses. Likewise, the filler strip 174 can expand with respect to the other parts. As will be seen, this structure provides for a minimum of thermal stress or distortion while positively locating and supporting the main seal.

The secondary seal retainer 176 is a rectangular frame made in two parts so that it can be fitted around the matrix and which is bolted to the support bars 50 and 51. Another secondary seal support frame, likewise in two parts, identified as 178, is bolted to the seal housing 54. The support frames define outer and inner grooves to receive the rectangular secondary seal. The secondary seal 179 is a rectangular frame of thin sheet metal with wires welded to the edges to define a somewhat flexible strip bridging the gap between the seal housing and the seal frame. By slight flexure or slight slippage of this seal in the slots in which it is mounted, the gap between the seal housing and the bulkhead is closed against the difference between highand low-pressure sides of the regenerator and the slight rocking movement of the seal housing is permitted. It will be noted that a portion of this secondary seal which extends past the edges of the matrix is shown in FIG. 4.

The seal bar 162 bears two projections 180 and is cut away between them to define a keyway 181 at the center plane of the matrix. A lug 183 on the seal housing 54 enters this keyway to locate the seal housing axially of the matrix. A similar lug 184 on the cold side of the seal housing enters a similar keyway in the lower support 51.

Small retainer plates 186 may be tack-welded to the surface of the seal bar 162 opposite to filler strip 174 to prevent any possibility of pin 168 dropping out, particularly when the pin is used in the upper seal in which position it is inverted with respect to that shown in FIGS. 11 and 12.

CIRCULATION OF LUBRICATING AND COOLING OIL Proper circulation of oil to the bearings of the rotatable structures for lubrication and also within the seal housing for cooling'is quite important, particularly since it should be remembered that in the preferred embodiment the temperature at the hot side of the matrix is over l,0O0 F. My main seal structure provides improved arrangements for circulating the oil and also for coupling the seal to the oil supply and return conduits in the regenerator. In this connection, the structure shown is that of the lower matrix seal and support assembly, but the structure of the upper matrix seal and support assembly is essentially the same so far as the lubrication is concemed.

Referring first to FIGS. 3, 6, and 7, the oil is fed to oil manifolds 66 mounted on the outer front end plate 47 by a pipe (not shown) coupled to an inlet conduit 187. Some of this oil is fed through a bore 188 in a nipple 190 which projects into a recess in the oil inlet adapter 88 bolted to shaft 75. The junction between these two is sealed by piston ring seals as shown. The oil continues through the central passage in the oil inlet adapter into the relatively large central bore 191 in the hollow shaft 75. Some of this oil flows outwardly through radial metering passages 192 and 194 near the ends of the shaft and along the reduced portions of the periphery of the shaft to the spherical bearings 76 by way of slots (not shown) in the face of roller 83. An outlet for the oil which has flowed through bearings 76 is provided at 195 in the lower portion of the oil manifold 66. The oil which is flowed through the other spherical bearing 76 flows into the space within oil drain cover plate 79 mounted on end plate 43. Also, some oil under pressure flows through a metering hole 196 in plate 87 fixed to the end of shaft 75. This metering hole determines the amount of oil which simply flows through the passage 1511, apart from that required for lubrication, to contribute to the cooling of the hot side roller.

The oil drain from the inner side of the matrix which, in the installation referred to, is between the two matrices and relatively inaccessible, includes an automatic plug-in arrangement by which the return oil line couples to a drain line (not illustrated). This structure includes a spring bellows 202 to which are fixed two heads or

flanges

203 and 204. Head 203 is bolted over an opening in the lower part of oil drain cover plate 79. Flange 204 bears a seal 206 in its outer face which bears against the structure to which it is connected and so held by the spring force of the bellows, these bellows also serving to take up any changes in dimension. Alignment of the oil drain connection with the fixed structure of the engine is assured by a pilot 207 comprising two crossed plates with tapered outer ends, thus providing a spider through which the oil can flow freely.

Oil is supplied to lubricate the cool side rollers 37 from manifold 66 through pivot 62. A passage 208 in the oil manifold communicates with a spigot 210 which enters a recess 211 in the pivot 62 from which it flows through a series of drilled intercommunicating passages, identified as 212 in the

pivot arm

59 and 213 in the cool side seal bar 55, into a distributing passage 215 extending from end to end of the cool side seal bar concentric with the axis of rollers 37. This oil flows outwardly through metering holes 216 in caps 103 and thus to the needle bearings 102. Oil can flow outwardly through small passages 218 in the stub shaft 97 to the ball thrust bearing 95, leakage of the oil being prevented by seals 106. The lower portions of the bearing recesses 98 are jointed by an oil drain passage 219 which intersects the downwardly extending central vent passage 220 which communicates through a flexible bellows 222 with a line 224 to a sump (not illustrated).

As will be apparent, the structure just described provides for adequate lubrication of the moving parts and for circula tion of some oil for cooling purposes while providing for ready assembly of the seal into the regenerator and coupling of the oil lines.

CONCLUSION it should be clear to those skilled in the art from the foregoing that the seal described and claimed herein represents a number of significant improvements over prior art devices and is particularly suited to the requirements of gas turbine regenerator installations.

The detailed description of the preferred embodiment of the invention for the purpose of explaining the principles thereof is not to be considered as limiting or restricting the invention, as many modifications may be made by the exercise of skill in the art.

lclaim:

l. A main seal for a rotary regenerator including a case, a bulkhead, a rotatable annular radial-flow matrix, and main seals cooperating with the matrix at the bulkhead; the main seal comprising, in combination, a housing including a first seal bar extending across the hotter face of the matrix, a second seal bar extending across the cooler face of the matrix, and sideplates connecting and rigidly fixed to the seal bars and adapted to extend across the edges of the matrix; the sideplates being adapted to undergo flexure to accommodate relative thermal expansion of the lengths of the seal bars; means connecting the sideplates to the case so as to support the sideplates from the case and the seal bars from the sideplates; and roller means engaging one face of the matrix mounted on the housing and supported by the sideplates.

2. A main seal for a rotary regenerator including a case, a bulkhead, a rotatable annular radial-low matrix having hotter and cooler faces, and main seals cooperating with the matrix at the bulkhead; the main seal comprising, in combination, a housing including a first seal bar extending across the hotter face of the matrix, a second seal bar extending across the cooler face of the matrix, and sideplates connecting and rigidly fixed to the seal bars and adapted to extend across the edges of the matrix; the sideplates being supported by the case and supporting the seal bars and being adapted to undergo flexure to accommodate relative thermal expansion of the lengths of the seal bars; the main seal also including two sets of matrix-engaging rollers engaging the said faces, one set being mounted in each seal bar, one set of rollers being rotatably supported by the case independently of the housing and the other set of rollers being supported by the sideplates.

3. A main seal for a rotary regenerator including a case, a bulkhead, a rotatable annular radial-flow matrix, and main seals cooperating with the matrix at the bulkhead; the main seal comprising, in combination, a housing including a first seal bar extending across and in sealing relation to the hotter face of the matrix, a second seal bar extending across and in sealing relation to the cooler face of the matrix, and sideplates connecting and rigidly fixed to the seal bars and extending across the edges of the matrix, the seal bars being rigid columnar structures and the sideplates being adapted to undergo flexure to accommodate relative thermal expansion of the lengths of the seal bars; the main seal also including two sets of matrix-engaging rollers engaging the hotter and cooler faces of the matrix, respectively, to locate and support the matrix, one of the said sets of rollers being supported by the said housing.

Claims

1. A main seal for a rotary regenerator including a case, a bulkhead, a rotatable annular radial-flow matrix, and main seals cooperating with the matrix at the bulkhead; the main seal comprising, in combination, a housing including a first seal bar extending across the hotter face of the matrix, a second seal bar extending across the cooler face of the matrix, and sideplates connecting and rigidly fixed to the seal bars and adapted to extend across the edges of the matrix; the sideplates being adapted to undergo flexure to accommodate relative thermal expansion of the lengths of the seal bars; means connecting the sideplates to the case so as to support the sideplates from the case and the seal bars from the sideplates; and roller means engaging one face of the matrix mounted on the housing and supported by the sideplates.

2. A main seal for a rotary regenerator including a case, a bulkhead, a rotatable annular radial-flow matrix having hotter and cooler faces, and main seals cooperating with the matrix at the bulkhead; the main seal comprising, in combination, a housing including a first seal bar extending across the hotter face of the matrix, a second seal bar extending across the cooler face of the matrix, and sideplates connecting and rigidly fixed to the seal bars and adapted to extend across the edges of the matrix; the sideplates being supported by the case and supporting the seal bars and being adapted to undergo flexure to accommodate relative thermal expansion of the lengths of the seal bars; the main seal also including two sets of matrix-engaging rollers engaging the said faces, one set being mounted in each seal bar, one set of rollers being rotatably supported by the case independently of the housing and the other set of rollers being supported by the sideplates.