DESCRIPTION
April 9, 1953 w . T. DENNISON 3084849
ENTRY AND BEARING AXIAL FLOW COMPRESSOR Filed May 18, 1960 2 Sheets leaves 1 FIG . 92
/ / Vl E/V7 0R WILLIAM T. Nison DEN line 4 . must M : W
LAWYERS April 9, 1963 w . T. DENNISON 3084849
ENTRY AND BEARING AXIAL FLOW COMPRESSOR 2 Sheets - 2 Sheet Filed May 18, 1960 the figure. 2
. Figure 1 May 5
i ice STATE INPUT BEARING AXIAL COMPRESSOR SUPPQRT FLQW William T. Dennison , West Hartford , Onn . , Assignor to United Aircraft Corporation , East Hartford , Connecticut , a Delaware corporation , filed May 18, 1960 29,981 Being No. '7 claims. ( @ L . 230-4122 ) This invention relates to axial compressor fiow - s , and deals more particularly with an improved construction and integrated to the air inlet and the support for the front bearing in such a machine.
The main object of this invention to provide an improved construction for supporting the front bearing an axial flow compressor in relation to the compressor casing or the mounting structure and the inner ends of the inlet guide vanes , said construction being compact in size, simple arrangement, which requires relatively few parts and enables easy access to the front of the compressor.
Another object of this invention to provide an improved support and lubrication means for the front bearing of the compressor.
A further object of this invention to provide a support structure for the front bearing of a compressor rotor through which the bearing is positioned relative to the oil sump or the lubricant scavenging chamber flows directly from the sump to the bearing result that none of the support members must be perforated or otherwise provided with apertures or passageways for the return of lubricant to the sump.
A further object of this invention to provide means for supporting the front bearing of the compressor from the inner ends of the inlet guide vanes so that the bearing is cantilevered from a single support member with the result radial that a measurable amount of flexibility is present in the bearing, such flexibility that serves to reduce the natural vibration frequency of the compressor rotor so that the rotor can be safely operated at normal speeds which are above the speed corresponding to that natural frequency.
Other objects and advantages of the invention will be apparent from the drawings and the description below.
The drawings show a preferred embodiment of the invention and this embodiment will be described , but it is understood that various changes may be made in the construction described and that the drawings and description should not be interpreted as defining or limiting the scope of the invention, the claims forming a part of this specification be invoked for this purpose.
Drawings :
. Figure 1 is a fragmentary sectional view taken in a plane passing generally through the longitudinal axis of a compressor axial fiow and showing a blade inlet and the front of the bearing support structure embodying this invention , having view taken through the inlet guide vane which contains the lubricant supply duct and parts behind the plane of the view being omitted for clarity,
. Figure 2 is a partial front view of the pallet scaled input and hinge construction is shown in Fig . 1 with the front cover is removed to more clearly show the bearing support structure ,
. Figure 3 is a fragmentary sectional view taken on line 33 'in FIG . 1 and drawn to a reduced scale of the figure. 1
. Figure 4 is a fragmentary sectional view taken through the inlet guide vane containing the lubricant duct sweeping parts behind the plane of the view being omitted for clarity , and
. Figure 5 is a partial sectional view taken along line 5-5 of Fig . April .
In the drawings where the purpose of illustration is shown a preferred embodiment of this invention, and referring first to FIGS . 1 and 2, reference numeral 10 generally indicates the air intake of the axial flow compressor . Gate 10 is of annular form and is defined by concentric , radially spaced inner and outer annular covers 12 and 14 , respectively. The outer cover 14 is adapted to be supported by the mounting structure suitable motor , not shown, by means of a flange extending radially outwards 16 formed in its upstream end and is provided with a plurality of apertures circumferentially spaced 18, 18 which serve for receiving mounting bolts or other fasteners.
Inner annular housing 12 is supported from the outer casing 14 via a plurality of inlet guide vanes 24 , 20) , as shown in Fig . 2, extend radially between the two shrouds and are arranged in an annular series of circumferentially spaced within the air inlet 10 . The inlet guide vanes 20, 20 have a cross section generally in the form of curved support surface and serve to direct the inlet air in proper operational relationship with the first stage rotor blades of the compressor. The blades of the first stage compressor rotor not shown in the figure. 1 but should be understood to lie directly to the right of the guide vane is shown therein . The guide vane is shown in Fig . 1 contains the lubricant supply conduit , as described in more detail below , but in other respects is similar to most other guide vanes 20, 20 . To distinguish the guide vane of Fig . 1, however , those not containing a lubricant supply conduit or additional elements , is designated by the reference 20a . Similarly, the guide vane shown in Fig . 4 containing the lubricant scavenging duct is designated by reference numeral 2 % to distinguish it from the other guide vanes 20, 20 . Again, both the guide vanes 20a and 20b are generally similar to the other guide vanes 20, 20 except for the addition of the lubricant supply conduits and sweeping thereof. Each guide vane is of hollow construction , as
best shown in FIGS . 3 and 5, and is closed at its inner end by an inner cover 22 and at its outer end by an outer covering 24. Opposite end portions of the fins fit into corresponding openings in the inner and outer casings 12 and 14 and are welded to the shroud , as indicated in Fig . 1.
From the figure. 1 also be seen that the outer cover 14 comprises an outer annular ring 26 and an inner annular ring 28 that collectively define an annular chamber 30 adjacent the closed outer end portions of the blades 20, 20 . Similarly, the cover 12 consists of inner annular ring 32 and an inner annular outer annular ring 34 which collectively define an annular chamber 36 adjacent the inner end portions of the blades 20, 20 . The 3t cameras and 36 serve as part of a system for the anti- airflow icing through the vanes 20, 20 and each paddle is provided with openings 38, 38 which communicate with the chambers 30 and 36 to provide air flow radially through the vanes . The anti - icing , however , is not part of this invention, the same structure in relation to the blades 20, 20 is made only by way of example, and other mounting means for the inner and outer ends the blades can be used with or without provision against icing without departing from the scope of this invention . The vanes 20, 20 need not be hollow , but when made in hollow shape is generally desirable that they each include a reinforcement 40 inside the fin extending radially along the length of the blade in engagement with the two opposite interior walls of the vane , as shown in FIGS . 3 and 5.
The compressor housing is generally indicated at 4-2 in Fig . 1 and is preferably integral with the outer annular housing 14, as shown. Housing 42 also preferably extends downstream a distance equal to about half the length of the rotor of the compressor and is at its downstream end connected to another housing portion that extends downstream to the rest of the length of the compressor to not require separate or additional compressor casing . The member 44 partially shown in Fig . 1 is the outer annular seal of the first stage compressor blades and connected to the outer annular casing 14 by a plurality of staggered pins , one of which is shown at 46.
Referring again to FIG . 1, it is seen that the cover 12 has an inner annular flange 48 integrally connected to its portion downstream edge and extending radially inward thereof. The flange 48 serves to support a cylindrical or sleeve that is connected to the support flange 48 by a plurality of bolts 52, 52 which pass through an annular flange that extends outward in the bracket 54 and through inner margin of support flange 48 . Pins 52 , 52 have nuts 56, 56 threadedly received in their upstream ends and a ring seal 58 is used between the flange 54 and the flange 48 , as shown in Fig . 1.
The bracket 50 , as shown in Fig . 1 extends axially upstream of the support flange 48 and beyond the downstream edges of the guide vanes 20 , 2t ) and serves to receive the front bearing 60 of the compressor rotor . The compressor rotor is not shown in detail in FIG . 1, but it is understood that the bearing portion 60 is in front of the rotor and integral with the bell end which is partially illustrated and is indicated at 62. The bearing portion 60 is rotatably supported relative to the carrier 50 via a roller bearing unit 64 that is positioned between the inner hole of the clamp 54) and the outer surface of the bearing portion 60 . The location of the bearing unit is such that it falls between the edges upstream and downstream of the guide vanes that is, the bearing unit is disposed in a radial plane , a plane normal to the rotation axis , which passes through the bodies of the guide vanes . The outer race 66 of the roller bearing'unit 64 is received by a corresponding hole portion 68 of the bracket 50 and held in place with respect to the holder by means of the retaining nut 70 which is threadedly connected to a portion 72 the bracket 50 which extends upstream from the bearing 64 , the outer race 66 includes a flange 74 which is held in engagementwith a shoulder holder hole by the retaining nut 70 .
Downstream of the bearing unit 64 is a seal 76 which closes the space between the bearing and the bracket 50 to prevent the escape of lubricant therebetween. 76 seal plate comprises two annular seals 78, 73 which are held in axially spaced relation by a spacer 80 , and two annular graphite seals 82, 32 each of which engages with the holder hole 50 and a radial face in a corresponding one of the plates together July 8, 78 . Right latch plate July 8 engages a rib formed on the 3-4 of bearing 60 , while the other plate gasket engages the downstream end of the outer race 86 of the bearing 6 ring outer race 86 , the two plate seals 78 , 7S ' and spacer 80 are in turn held in place in the bearing part 60 by means of a retaining nut 88 which is threadably received by the end portion upstream of the bearing part 60 . Loosening movement of the retaining nut 88 is prevented by a tablock 90 . The bearing part is hollow and the upstream end portion thereof is closed by a circular cap 92v is held in place by a shoulder 94 and a retaining ring 96 .
From the foregoing and by reference to FIG . 1 , note that the support flange 48 serves as the only support for the radial support 5i ) and the bearing 64, and it was also observed that the bearing 64 - is upstream of the flange 43 in order to be supported Similarly on a cantilever . In this regard it is noted that the oil supply duct , later described , form no substantial part of the structural support for the support. The cantilever support arrangement for the bearing 64 provides for a certain amount of flexibility in the bearing and thus provides a compressor rotor natural frequency lower than would be the case if the bearing supports sturdier has generally been the case with prior constructions . Rotor speed corresponding to the lowest natural frequency of the vibration produced by this mounting arrangement has been found to be sufficiently below the normal operating speed of the rotor so that the rotor in normal operation will function safe and well above its natural frequency . Moreover, since the bearing 64 is axially aligned with the guide vanes , the radial loads imposed on the support act along radial lines passing through the guide vanes so that torque loads on the shrouds , vanes and other engine parts are minimized .
Besides the advantages achieved by the bearing support structure with respect to the lowest natural frequency , the structure shown at present has more advantages in relation to the provision of means for lubricating the bearing 64 . Since the bearing 64 is subjected to the relatively severe operating conditions , it is desirable to be lubricated by a pressurized spray system . Referring to FIG . 1 , this system includes an oil supply conduit 98 extending through the guide vane 29th . At its outer end of conduit 98 extends beyond the outer cover 24 of the flap 20a has associated therewith a suitable connector 160 for receiving a complementary connector 102 which connects the conduit 98 to another conduit 104 which leads a source of pressurized lubricant . The inner end of conduit 98 extends inwardly beyond the inner cover 22 of the truck 20a and is supported by a sleeve surrounding 106 attached to the cover 22 , the sleeve 106 containing a stamp 1118 which is coupled to the surface outside the conduit 98 . The conduit 98 extends inwardly beyond the inner end of the sleeve 106 and has at its end portion a nozzle 110 having an orifice 112. Port 112 is directed in a generally downstream direction to spray lubricant from the conduit 5 8 on the annular space between the support 50 and the bearing journal 64 portion'60 . Between the inner end of conduit 98 and the nozzle orifice 112 is a filter screen or lubricant 114. The nozzle 119 is , as shown in Fig . 2 secured by threaded fasteners 115, 115 to a tab 116 formed on the upstream end of the bracket 50 and extending radially outwardly therefrom .
Around the clamp 50 is an annular manifold chamber 118 or sweep lubricant . The inner surface of the inner annular housing 12 including the inner flap covers 22 , 22, defines the outer periphery of the scavenging chamber 118, while the support flange 48 defines the right wall of the chamber. The left wall of the chamber is defined by a circular front cover 120 which is secured to a flange 122 extends radially inwardly at the upstream edge of the inner annular housing 12. The support 50 projects freely in the center of the chamber 118 with the result that the upstream side of the bearing 64 is in direct communication along its circumference with the chamber 118 and the inner surface of the inner annular housing 12 which serves as the periphery of the chamber . Therefore, the spent oil or lubricating media can flow directly from the bearing 64 to the outer portions and bottom of the chamber 118 without passing through any member or structural members . This means that none of the structural support members for the bearing has to be perforated or otherwise provided with passages to allow the flow of lubricant to the compression chamber. This, of course , is important in reducing the stress concentration factors unknown to the structure of the compressor.
Lubricant drains into the bottom of the sump or scan camera 118 is removed therefrom by means of a scanning conduct 124 extending radially through the vane 20b, the pallet 2% being located at the lowermost position or six o'clock in the air inlet , as shown in Fig . Two . As shown in the figures. 4 and 5, the waste collection pipe 124 has a flattened cross-section at its inner end and has a mouth 126 positioned adjacent the inner surface of the cover 12 , the cover being in - vane 22 , considered part of the inner surface of the cover 12 , so that the lubricant which is installed on the bottom of the chamber 118 will be withdrawn therefrom through the mouth 126. At its lower end scanning conduit 124 extends through the outer cover 24 and has associated therewith a coupling member 128 which receives a complementary coupling member 130 for connecting the waste collection conduit to another conduit 132 that returns the lubricant to the lubricant .
In addition to providing for proper lubrication of the bearing 64 which is also observed that the lubrication system as described above is integrated with the bearing support structure that both the support structure and the lubrication system forms a compact arrangement of the parts take up little space and require fewer components .
The invention claimed is:
1. The combination of an axial flow compressor , radially spaced inner and outer annular cover concentrically disposed to define an annular air inlet to said compressor , a plurality of guide vanes extending radially arranged in an annular array circumferentially spaced apart from said cover interior and exterior and having their inner ends fixedly secured to said inner cover and outer ends fixedly secured to said outer cover , an annular supporting portion connected to an edge only of said inner cover and extending radially inwardly thereof, a cylindrical support bracket connected to the radially inner portion of said support bracket and extending axially therefrom toward the other edge portion of said inner cover , a rotor which has a bearing part forwardly positioned within said support , and an antifriction bearing between said support and said part of the rotor journal for rotatably supporting portion of said magazine with respect to said support , said bearing being axially spaced from said mounting flange and located in a radial plane passing through said guide vanes so that said bearing is supported flexibly cantilevered from said flange for supporting said cylindrical support .
Two . The combination of an axial flow compressor , radially spaced inner and outer annular cover concentrically disposed to define an annular air inlet to said compressor , a plurality of guide vanes extending radially arranged in an annular array circumferentially spaced apart from said cover inner and outer ends and having inside fixedly secured to said inner cover and outer ends fixedly secured to said outer cover , a flange connected to the annular support only said inner cover along the edge portion of downstream of the latter and extending radially inwardly thereof, a support bracket connected to the cylindrical inner edge of the bearing flange and extending axially at a distance upstream thereof and beyond the edges water downstream of said inlet guide vanes, a rotor having a forward bearing portion positioned within said cylindrical support , and an antifriction bearing between said support and said rotor journal portion for rotatably supporting said journal portion with respect to said support , somedistance said bearing is located upstream of said mounting flange in a radial plane passing through said guide vanes so that said bearing is flexibly supported in cantilever fashion from said flange for supporting said cylindrical holder.
Three . The combination of an axial flow compressor , radially spaced inner and outer annular cover concentrically disposed to define an annular air inlet to said compressor , a plurality of guide vanes extending radially arranged in an annular array circumferentially spaced being - 7 and said inner support housing , a rotor having a forward bearing portion of said carrier positioned within a bearing support betweensaid magazine and said rotor portion for rotatably supporting said magazine portion of said support with respect to a lubricant supply conduit means extending radially through one of said guide vanes and inwardly beyond said inner housing and having a nozzle at its inner end arranged to spray lubricant said conduit means on said support , and a conduit for collecting waste lubricant which extends radially through the other of said guide vanes and having an inner surface adjacent said opening therein for receiving lubricant coating which is collected in said chamber adjacent to said surface of the latter.
April . The combination of an axial flow compressor , radially spaced inner and outer annular cover concentrically disposed to define an annular air inlet to said compressor , a plurality of guide vanes extending radially arranged in an annular array circumferentially spaced apart from said cover inner and outer ends and having inside fixedly secured to said inner cover and outer ends fixedly secured to said outer cover , a flange connected to the annular support only said inner cover along the edge portion of downstream of the latter and extending radially inwardly thereof, a support bracket connected to the cylindrical inner edge of the bearing flange and extending axially at a distance upstream thereof in superposed relationship with said cover axially inward so that an open annular space is defined between said support and said inner cover , a rotor having a forward bearing portion of said carrier positioned within a bearing between said support and said rotor portion magazine for rotatably supporting said journal portion with respect to said support , said bearing is axially spaced upstream from said mounting flange in order to be supported in cantilever fashion and said annular support itself be of such length as to extend axially upstream most beyond said bearing lubricant nozzle portion connected to the upstream end of said support and arranged for spraying lubricant in a generally downstream direction in said bearing , and means of lubricant supply conduit for delivering lubricant pressure to said nozzle and duct means extending through one of said guide vanes and inwardly beyond said inner cover for connection to said nozzle .
May . The combination of an axial flow compressor , means defining an annular inlet means to said compressor and includes an annular cover inside, a support member connected to said annular inner housing only along the edge portion downstream of the latter and extending radially inwardly thereof, a cylindrical support member connected to said support and extending axially upstream thereof at radially and axially spaced relationship to said inner cover overlying a compressor rotor having bearing part positioned within said support , and a bearing between said support and said part of the magazine for rotatably supporting said journal portion with respect to said support , said inner cover and said annular support member defining respectively the outer peripheral wall and the radial wall downstream of a compaction lubricant annular chamber in which said support projects chamber of said annular supporting member with the result that the upstream side of said bearing is in direct communication with the outer periphery of said lubricant compaction chamber along the entire circumference thereof so that the lubricant of the bearing 7 can flow directly to said waste collection chamber without passing through any structural member or members. j 6 . The combination as defined in claim 5, further characterized by a lubricant removal conduit extending through one of said guide vanes and having an opening adjacent the inner surface of said inner shell for the drainage of lubricant from said chamber . 7
July . The combination of an axial flow compressor , radially spaced inner and outer annular cover concentrically disposed to define an annular air inlet to said compressor , a plurality of guide vanes extending radially arranged in an annular array circumferentially spaced apart from said cover inner and outer ends and having inside to'said fixedly secured inner cover and outer ends fixedly secured to said outer cover , a support flange annular portion connected to the downstream edge of said inner cover and extending radially inwardly thereof, a support bracket connected to the cylindrical inner edge of the bearing flange and extending axially at a distance upstream thereof at radially and axially spaced relationship with said inner cover overlying a rotor having a forward bearing portion of said carrier positioned within a bearing between said support and said rotor portion magazine for rotatably supporting portion of said magazine with respect to said support , said clamp and said annular support portion forward bearing having their upstream ends spaced at a distance downstream of the upstream edge portion of said inner cover , means for supplying lubricant to said bearing , a cover connected to the upstream edge portion of said inner cover to cover closes the upstream end of said deck and defines an annular wall of a collection chamber lubricantleaving said bearing , the other walls of said chamber is defined by the inner surface of said inner cover , said annular support flange and said bracket annular support .
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