Gas Compressor

Abstract

The arrangement is described in use in a gas compressor which is of the axial flow type, having a plurality of stages of compression, and an overhung rotor. The arrangement comprises vane mounting rings, for emplacement within a cylindrical housing, in which the stator vanes are pinned. Further, each vane is set in an elastomer for dampening or to accommodate for vibratory movement thereof. A housing and frame enclose and support the working elements of the compressor, the elements being so supported and enclosed as to allow for relative movements of the housing without causing distortion of said elements.

Parent Case Text

This is a division of application Ser. No. 235,501; filed Mar. 17, 1972 now U.S. Pat. No. 3,773,430.

Description

This invention pertains to stator vane mounting arrangements for use in gas compressors, and in particular to gas compressors of the axial flow type where stator vanes are subject to vibration-induced failures a plurality of stages of compression.

It is an object of this invention to set forth a stator vane mounting arrangement which especially accommodates for vibratory movement of stator vanes. Especially it is an object of this invention to teach means for dampening vibratory movement of stator vanes.

Another object of this invention is to set forth an arrangement for mounting stator vanes in a stator housing, for use in a gas compressor, comprising a vane mounting ring, said ring having a recess formed therein for receiving a vane therewithin; a vane having an end thereof disposed within said recess; pin means securing said vane end in said recess; and resilient means enveloping said vane end and dampening said vane against vibration.

Further objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying figures, in which:

FIG. 1 is an axial view, partly in cross-section, of an arrangement for mounting stator vanes in use in a embodiment of a gas compressor, according to the invention;

FIG. 2 is an enlarged view of a detailed area of FIG. 1; and

FIGS. 3 and 4 are side and plan views depicting the stator vane and mounting ring arrangements.

As shown in the figures, the novel gas compressor 10 comprises a housing 12 having a base 14 for supporting the housing thereupon. A pair of oppositely disposed gas inlet flanges 16 are mounted to each side of the housing, the flanges defining inlet ports 18 which open on a chamber 20 defined within the housing. At the axial outlet end of the compressor is mounted a gas discharge flange 22 having an outlet port 24 formed therein.

Upstream of the inlet end are carried coupling means and a bearing housing assembly (not shown), the two being supported in a casing 26 which is fixed to the compressor base 14. An over-hung, axially extending rotor and shaft assembly 28 is rotatably supported at but one axial end in the bearing housing, for rotary, gas-compressing movement within a compression chamber 30, and includes pluralities of radially disposed blades 32. A vaned stator 34, concentrically disposed about the rotor and shaft assembly, is mountedly supported within the compressor housing, by means of a cylindrical housing 36 which carries vane mounting rings 38 therewithin. The stator 34 comprises a plurality of such vane mounting rings in juxtaposition, each of which has fixed therein a plurality of vanes 40. All of the vanes 40 are of uniform length; however, the stator mounting rings 38 are of uniformly varying cross-section, from the inlet end to the outlet end of the compression chamber so that, toward the outlet end, progressively less of the vanes 40 protrudes into the compression chamber 30. Each vane 40 is pinned into its respective mounting ring 38 and, further, each vane head 42 is set in an elastomer 44 for the purpose of damping vane vibration.

The housing base 14 comprises a vertical plate 46 which has passageways (not shown) formed therein for the admittance of ambient atmosphere as a sealant and also for introducing lubricating oil. Also, the lubricating oil is conducted by drilled passageway 48 from annular seals 50,50a set about the shaft of the rotor and shaft assembly 28 and subsequently drains into the bearing housing assembly.

The rotor and shaft assembly 28 comprises a plurality of juxtapositioned blade mounting rings 52, each of the rings having a plurality of the blades 32 mounted therein and radially extending away therefrom. Each blade 32 at the head end thereof has a forked extension 54 which is bored through to receive a pin 56. Further, each blade mounting ring has a plurality of boreholes 58 formed therethrough for retaining opposite ends of the blade-retaining pins. Each blade, at the head end thereof, has a laterally extending tang 60 which protrudes into a complementary, interfacing recess 62 provided therefor in an adjacent blade head end. Finally, the forked extensions 54 of adjacent blades have cooperative, arcuate cut-outs 64 formed therein with an elastomeric insert 66 therebetween. The pinning of the forked extensions, and the elastomeric inserts, cooperate to allow the blades to swing through a small arc to accommodate for vibration.

The rotor shaft has a hollow extension 68 about which the rotor blade mounting rings 52 are mounted.

At the outlet end of the gas compressor is disposed a diffuser shell 72 which is open at both, opposite, ends. One end is in direct open communication with the outlet end of the compression chamber 30, and the end opposite opens directly onto the outlet port 24. One end, the outlet end of this diffuser shell, is retained by a circumferential shoulder 74 formed within the outlet flange and about the outlet port. The diffuser shell outlet end and the circumferential shoulder have a compliant, sealant medium 76 therebetween. Further, the compressor housing has a radially and inwardly extending weldment 78 which abuttingly receives a radial ring 80 formed about and extending from the diffuser shell, said weldment and ring having an O-ring seal 82 therebetween.

Another ring 82 is welded within the outlet end of the housing, intermediate the weldment 78 and the outlet end of the diffuser shell 72, to present a flat-surfaced annulus for slidably supporting the diffuser shell therewithin. Four ribs 86 (only one is shown), equally spaced therebetween about the rotor axis, are fixed at either ends thereof to the annulus of ring 84 and the weldment 78 to provide further support for the diffuser shell therewithin and for the outlet end of the compressor.

The blade mounting rings 52 of the rotor, and the vane mounting rings 38 of the stator as well, are each independently replaceable. The innermost blade mounting ring (i.e., the one nearest the inlet end of the compression chamber) is set up against a circumferential shoulder 88 formed in the outer surface of the rotor shaft extension 68. Successive adjacently-disposed blade mounting rings 52 are set against the innermost one, along the shaft axis. The last or outermost blade mounting ring is secured on the rotor shaft extension by a retainer plate 90 bolted (by means not shown) to the shaft extension.

The vane mounting rings 38 of the stator, similarly are set one against the one adjacent thereto, with the innermost one set against a radial shoulder 92 formed in a cylindrical stator housing 36. The outermost vane mounting ring is secured in position by means of a bi-stepped retainer ring 96. One step 98 of the retainer ring abuttingly receives the outlet end of the stator housing 94, and the retainer ring is secured to said stator housing thereat. The other step 100 of the retainer ring, being disposed on a face of the ring opposite the first-mentioned step, abuttingly receives the inlet end of the diffuser shell 72. O-ring seals are disposed in both steps to fluid seal the joints formed thereat with the abutting components.

The novel stator vane mounting arrangement herein described in conncation with a compressor, due to the independent replaceability of the vane mounting rings 38, renders maintenance and repair easy, and accommodates a facile re-rating of the compressor. Simply by replacing given outermost mounting rings with dummy rings or spacers, or by wholly substituting differently-dimensioned and/or configured vanes -- in replacement mounting rings, -- the performance of the compressor can be altered.

While we have described our invention in connection with a specific embodiment thereof, it is to be clearly understood that this is done only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the appended claims.

Claims

1. An arrangement for mounting stator vanes in a stator housing, for use in a gas compressor, comprising:

a vane mounting ring, said ring having a recess formed therein for receiving a vane therewithin;

a vane having an end thereof disposed within said recess, with a pin therethrough securing said vane end to said ring and in said recess; and

resilient means enveloping said vane end in said recess and dampening said

2. An arrangement, according to claim 1, wherein: said resilient means

3. An arrangement, according to claim 2, wherein: said elastomer wholly envelops said vane end and fills said recess.