TILT PAD JOURNAL BEARING WITH LUBRICATION ARRANGEMENT

Abstract

A tilt pad journal bearing for supporting a rotating shaft includes an annular support ring and a plurality of arcuate pads tiltably mounted in the annular support ring and circumferentially spaced apart from each other. The tilt pad journal bearing further has a lubrication arrangement disposed between each pair of the plurality of arcuate pads. The lubrication arrangement includes a lubrication manifold connected to the annular support ring and recessed relative to a shaft support surface of adjacent arcuate pads to define an oil mixing cavity, and a plurality of lubrication nozzles protruding from the lubrication manifold into the oil mixing cavity. A cross-sectional flow area of at least one of the plurality of lubrication nozzles positioned toward a center of the lubrication manifold is larger than a cross-sectional flow area of a remainder of the plurality of nozzles.

Claims

1. A tilt pad journal bearing for supporting a rotating shaft, the tilt pad journal bearing comprising: an annular support ring; a plurality of arcuate pads tiltably mounted in the annular support ring and circumferentially spaced apart from each other, each of the plurality of arcuate pads having a mounting surface opposite a shaft support surface; and a lubrication arrangement disposed between each pair of the plurality of arcuate pads, the lubrication arrangement comprising: a lubrication manifold connected to the annular support ring and recessed relative to the shaft support surface of adjacent arcuate pads to define an oil mixing cavity, and a plurality of lubrication nozzles protruding from the lubrication manifold into the oil mixing cavity, wherein a cross-sectional flow area of at least one of the plurality of lubrication nozzles positioned toward a center of the lubrication manifold is larger than a cross-sectional flow area of a remainder of the plurality of nozzles positioned away from the center of the lubrication manifold.

2. The tilt pad journal bearing of claim 1, wherein the annular support ring has a lubricant delivery hole in fluid communication with the lubrication manifold and each of the plurality of lubrication nozzles.

3. The tilt pad journal bearing of claim 1, wherein the plurality of lubrication nozzles is three lubrication nozzles.

4. The tilt pad journal bearing of claim 1, wherein the plurality of lubrication nozzles are evenly or unevenly spaced apart from each other along the lubrication manifold.

5. The tilt pad journal bearing of claim 1, wherein at least one of the plurality of lubrication nozzles with the larger cross-sectional flow area has 33% to 200% more flow area than any of the remaining individual lubrication nozzles.

6. The tilt pad journal bearing of claim 1, wherein at least one of the plurality of lubrication nozzles has a circular cross-sectional flow area.

7. The tilt pad journal bearing of claim 1, wherein at least one of the plurality of lubrication nozzles has an oval cross-sectional flow area.

8. The tilt pad journal bearing of claim 1, wherein at least one of the plurality of lubrication nozzles has a prismatic outer shape.

9. The tilt pad journal bearing of claim 1, wherein the lubrication manifold comprises at least one threaded hole, and wherein the lubrication manifold is connected to the annular support ring via a fastener threadably engaged with the at least one threaded hole.

10. The tilt pad journal bearing of claim 1, further comprising a spherical pivot seat in contact with the mounting surface of each of the plurality of arcuate pads.

11. The tilt pad journal bearing of claim 10, wherein the spherical pivot seat is connected to an inner surface of the annular support ring.

12. The tilt pad journal bearing of claim 1, wherein an upper surface of the plurality of lubrication nozzles is recessed relative to the shaft support surface of adjacent arcuate pads.

13. The tilt pad journal bearing of claim 1, further comprising a pair of end seals connected to the annular support ring.

14. The tilt pad journal bearing of claim 1, further comprising at least one temperature transducer connected to at least one of the plurality of arcuate pads.

15. The tilt pad journal bearing of claim 13, wherein the at least one of the plurality of lubrication nozzles with the larger cross-sectional flow area is positioned in axial alignment with the at least one temperature transducer.

16. A tilt pad journal bearing for supporting a rotating shaft, the tilt pad journal bearing comprising: an annular support ring; a plurality of arcuate pads tiltably mounted in the annular support ring and circumferentially spaced apart from each other, each of the plurality of arcuate pads having a mounting surface opposite a shaft support surface; and a lubrication arrangement disposed between each pair of the plurality of arcuate pads, the lubrication arrangement comprising: a lubrication manifold connected to the annular support ring and recessed relative to the shaft support surface of adjacent arcuate pads to define an oil mixing cavity, and a plurality of lubrication nozzles protruding from the lubrication manifold into the oil mixing cavity, wherein a cross-sectional flow area of at least one of the plurality of lubrication nozzles positioned toward a center of the lubrication manifold is larger than a cross-sectional flow area of a remainder of the plurality of nozzles positioned away from the center of the lubrication manifold, and wherein an upper surface of the plurality of lubrication nozzles is recessed relative to the shaft support surface of adjacent arcuate pads, and wherein the annular support ring has a lubricant delivery hole in fluid communication with the lubrication manifold and each of the plurality of lubrication nozzles.

17. The tilt pad journal bearing of claim 16, wherein at least one of the plurality of lubrication nozzles with the larger cross-sectional flow area has 33% to 200% more flow area than any of the remaining individual lubrication nozzles.

18. The tilt pad journal bearing of claim 16, wherein at least one of the plurality of lubrication nozzles has a circular or oval cross-sectional flow area, and wherein at least one of the plurality of lubrication nozzles has a prismatic outer shape.

19. The tilt pad journal bearing of claim 16, wherein an upper surface of the plurality of lubrication nozzles is recessed relative to the shaft support surface of adjacent arcuate pads.

20. The tilt pad journal bearing of claim 16, further comprising a pair of end seals connected to the annular support ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 is a partial-cutaway perspective view of a multi-stage, centrifugal-flow turbomachine in accordance with a prior art embodiment;

[0038] FIG. 2 is a perspective view of a tilt pad journal bearing in accordance with some non-limiting embodiments or aspects of the present disclosure;

[0039] FIG. 3 is a perspective view of an annular support ring of the bearing shown in FIG. 1;

[0040] FIG. 4 is a perspective view of a lubrication arrangement configured for use with a tilt pad journal bearing in accordance with one non-limiting embodiment or aspect of the present disclosure;

[0041] FIG. 5 is a perspective view of a lubrication arrangement configured for use with a tilt pad journal bearing in accordance with another non-limiting embodiment or aspect of the present disclosure;

[0042] FIG. 6 is a front cross-sectional view of the lubrication arrangement shown in FIG. 4; and

[0043] FIG. 7 is a perspective view of a tilt pad journal bearing in accordance with another embodiment or aspect showing a temperature transducer.

DESCRIPTION OF THE DISCLOSURE

[0044] As used herein, the singular form of a, an, and the include plural referents unless the context clearly dictates otherwise.

[0045] Spatial or directional terms, such as left, right, inner, outer, above, below, and the like, relate to the embodiments or aspects as shown in the drawing figures and are not to be considered as limiting as the embodiments or aspects can assume various alternative orientations.

[0046] All numbers used in the specification and claims are to be understood as being modified in all instances by the term about. By about is meant within plus or minus twenty-five percent of the stated value. However, this should not be considered as limiting to any analysis of the values under the doctrine of equivalents.

[0047] Unless otherwise indicated, all ranges or ratios disclosed herein are to be understood to encompass the beginning and ending values and any and all subranges or subratios subsumed therein. For example, a stated range or ratio of 1 to 10 should be considered to include any and all subranges or subratios between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges or subratios beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less. The ranges and/or ratios disclosed herein represent the average values over the specified range and/or ratio.

[0048] The terms first, second, and the like are not intended to refer to any particular order or chronology, but refer to different conditions, properties, or elements.

[0049] All documents referred to herein are incorporated by reference in their entirety.

[0050] The term at least is synonymous with greater than or equal to.

[0051] As used herein, at least one of is synonymous with one or more of. For example, the phrase at least one of A, B, or C means any one of A, B, or C, or any combination of any two or more of A, B, or C. For example, at least one of A, B, and C includes A alone; or B alone; or C alone; or A and B; or A and C; or B and C; or all of A, B, and C.

[0052] The word comprising and comprises, and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. In the present specification, comprises means includes and comprising means including.

[0053] As used herein, the terms parallel or substantially parallel mean a relative angle as between two objects (if extended to theoretical intersection), such as elongated objects and including reference lines, that is from 0? to 5?, or from 0? to 3?, or from 0? to 2?, or from 0? to 1?, or from 0? to 0.5?, or from 0? to 0.25?, or from 0? to 0.1?, inclusive of the recited values.

[0054] As used herein, the terms perpendicular, transverse, substantially perpendicular, or substantially transverse mean a relative angle as between two objects at their real or theoretical intersection is from 85? to 90?, or from 87? to 90?, or from 88? to 90?, or from 89? to 90?, or from 89.5? to 90?, or from 89.75? to 90?, or from 89.9? to 90?, inclusive of the recited values.

[0055] The present disclosure is directed to, in general, a bearing 200, which may be a tilt pad journal bearing having a lubrication arrangement for increased bearing performance. The lubrication arrangement is configured to direct lubricant, such as oil, to the rotating shaft. Certain preferred and non-limiting embodiments or aspects of the components of the bearing 200 are illustrated in FIGS. 2-6. The present disclosure is also directed to, in general, a turbomachine that utilizes the aforementioned bearing 200. The bearing 200 is configured to be contained within a casing of a turbomachine. In some embodiments or aspects, the bearing 200 may be configured for use with a turbomachine, such as the turbomachine 10 shown in FIG. 1. A plurality of bearings 200 may be spaced apart in multiple stages along the axial length of the shaft of the turbomachine.

[0056] With reference to FIGS. 2-3, the bearing 200 includes an annular support ring 202 and a plurality of arcuate pads 204 supported in the annular support ring 202. The annular support ring 202 may be a monolithic structure having a central opening 206. In some embodiments or aspects, the annular support ring 202 may be a modular component constructed from a plurality of discrete ring or arc segments that are combined together to form the annular support ring 202. The discrete ring or arc segments may be removably connectable together one or more fasteners. In some embodiments or aspects, dowels, pins, or other structures may be provided for locating the discrete ring or arc segments relative to each other.

[0057] With continued reference to FIGS. 2-3, the bearing 200 further includes a pair of side plates 208 axially spaced from each other on opposing sides of the annular support ring 202. The side plates 208 are ring-shaped and include a central aperture 210 sized to receive a rotor shaft, such as the shaft 20 of the turbomachine 10 shown in FIG. 1. The side plates 208 are configured to be removably connectable to the respective opposing sides of the annular support ring 202. In some embodiments or aspects, the side plates 208 may be integrally formed with the annular support ring 202. Each side plate 208 has a plurality of openings 209 (shown in FIG. 3) configured to receive a corresponding plurality of retaining fasteners 212 (shown in FIG. 2) for axially and radially retaining the arcuate pads 204. In some embodiments or aspects, each arcuate pad 204 may be secured by a pair of retaining fasteners 212. In use, the side plates 208 axially and radially retain the plurality of arcuate pads 204 and suppress axial leakage of lubricant, as discussed herein. As such, each of the side plates 208 defines an end seal.

[0058] With reference to FIG. 2, the arcuate pads 204 are received within the central opening 206 of the annular support ring 202 and are circumferentially spaced apart from each other such that a gap or space 214 exists between adjacent arcuate pads 204. In some embodiments or aspects, the bearing 200 may have five arcuate pads 204. In other embodiments or aspects, the bearing 200 may have more or fewer arcuate pads 204. Each of the plurality of arcuate pads 204 has a mounting surface 216 (shown in FIG. 7) opposite a shaft support surface 218. The mounting surface 216 is configured for tiltably supporting the arcuate pad 204 on an inner surface 220 (shown in FIG. 3) of the annular support ring 202 via a spherical pivot seat, as described hereinafter. The shaft support surface 218 is configured to be in bearing contact with the rotor shaft supported by the bearing 200.

[0059] As shown in FIG. 7, the mounting surface 216 of each arcuate pad 204 has a pocket configured for contacting a spherical pivot seat 222 that is received within a pocket 224 (shown in FIG. 3) on the annular support ring 202. The spherical pivot seat 222 may be secured within the pocket 224 by a fastener 226 extending through a hole 228 (shown in FIG. 3) in the annular support ring 202. The spherical pivot seat 222 is configured to facilitate tilting movement of the actuate pads 204 about an axis that is parallel to a longitudinal axis of the bearing 200.

[0060] With reference to FIG. 2, the bearing 200 has a lubrication arrangement 232 disposed between each pair of the plurality of arcuate pads 204. The lubrication arrangement 232 is configured to deliver a lubricant, such as lubricating oil, to the rotor shaft. The discussion of the lubrication arrangement 232 will be with respect to a single lubrication arrangement 232, with an understanding that all of the lubrication arrangements 232 of the bearing 200 are preferably constructed in an identical manner.

[0061] With reference to FIGS. 4-5, the lubrication arrangement 232 includes a lubrication manifold 234 and a plurality of lubrication nozzles 236 protruding from the lubrication manifold 234. Each of the lubrication nozzles 236 is in fluid communication with the lubrication manifold 234 (see FIG. 6). In some embodiments or aspects, the plurality of lubrication nozzles 236 may be three lubrication nozzles 236. In other embodiments or aspects, the plurality of lubrication nozzles 236 may be more or less than three lubrication nozzles 236.

[0062] With reference to FIG. 2, the lubrication manifold 234 is configured to be connected to the annular support ring 202. For example, the lubrication manifold 234 has a pair of threaded holes 238 (shown in FIGS. 4-5), each of which is configured to threadably receive a fastener 240 that extends through a corresponding hole 241 on the annular support ring 202 (see FIGS. 2-3).

[0063] As shown in FIG. 6, the annular support ring 202 has a lubricant delivery hole 242 in fluid communication with the lubrication manifold 234 and each of the plurality of lubrication nozzles 236. In this manner, lubricant can be delivered from a lubricant source to the lubrication nozzles 236 via the lubricant delivery hole 242 and the lubrication manifold 234. In some embodiments or aspects, a seal may be provided at the interface between the lubrication manifold 234 and the annular support ring 202 to prevent side leakage of lubricant.

[0064] With reference to FIGS. 4-5, each of the lubrication nozzles 236 has a hollow structure configured for delivering lubricant to the rotor shaft via the lubrication manifold 234. The plurality of lubrication nozzles 236 are evenly spaced apart from each other along the lubrication manifold 234. In other embodiments or aspects, the plurality of lubrication nozzles 236 may be unevenly spaced apart from each other along the lubrication manifold 234. A cross-sectional flow area of at least one of the plurality of lubrication nozzles 236 positioned toward a center of the lubrication manifold 234 (i.e., a central lubrication nozzle 236a) is larger than a cross-sectional flow area of a remainder of the plurality of nozzles 236 positioned away from the center of the lubrication manifold 234 (i.e., outer lubrication nozzles 236b, 236c). In this manner, more lubricant can be delivered through the central lubrication nozzle 236a relative to outer lubrication nozzles 236b, 236c. This arrangement provides more efficient cooling of the bearing pad 204, thereby enabling the highest temperature reduction overall, as well as the highest temperature reduction per oil flowrate. In some embodiments or aspects, the central lubrication nozzle 236a with the larger cross-sectional flow area has 33% to 200% more flow area than any of the remaining individual lubrication nozzles 236b, 236c.

[0065] In some embodiments or aspects, at least one of the plurality of lubrication nozzles 236 has a circular cross-sectional flow area (FIG. 4). In other embodiments or aspects, at least one of the plurality of lubrication nozzles 236 has an oval cross-sectional flow area (FIG. 5). In further embodiments or aspects, at least one of the plurality of lubrication nozzles 236 may have any other geometric shape of the cross-sectional flow area. At least one of the plurality of lubrication nozzles 236 has a prismatic outer shape. For example, the outer cross-sectional shape of at least one of the plurality of lubrication nozzles 236 may be square, rectangle, or another shape.

[0066] With reference to FIG. 6, an upper end 246 of each of the plurality of lubrication nozzles 236 is recessed relative to the shaft support surface 218 of adjacent arcuate pads 204 by a distance X to provide a clearance space relative to the rotor shaft. Furthermore, the lubrication manifold 234 is recessed relative to the upper end 246 of each of the plurality of lubrication nozzles 236 and shaft support surface 218 of adjacent arcuate pads 204 to define an oil mixing cavity 248. The oil mixing cavity 248 is configured to receive hot lubricant that may drain from the adjacent arcuate pads 204 so that it may be mixed with the cooler lubricant delivered from the lubrication nozzles 236. In this manner, an overall bearing metal temperature can be reduced.

[0067] With reference to FIG. 7, at least one temperature transducer 250 is connected to at least one of the plurality of arcuate pads 204. The at least one temperature transducer 250 is configured for measuring the operating temperature of the bearing 200. In some embodiments or aspects, the at least one temperature transducer 250 may be in axial alignment with at least one of the plurality of lubrication nozzles 236 with the larger cross-sectional flow area.

[0068] While various aspects of the disclosed bearing and turbomachine were provided in the foregoing description, those skilled in the art may make modifications and alterations to these aspects without departing from the scope and spirit of the invention. For example, it is to be understood that this disclosure contemplates that, to the extent possible, one or more features of any aspect can be combined with one or more features of any other aspect. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of equivalency of the claims to be embraced within their scope.