Electrical discharge machining (EDM) front edge groove bearing
By setting a leading edge groove on the flexible support bushing of the bearing, the problem of heat retention in the prior art is solved by directly supplying low-temperature lubricant, which achieves tighter tolerance control and reduces mechanical failures, thus improving the performance of the rotary bearing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INGERSOLL RAND IND US INC
- Filing Date
- 2026-01-27
- Publication Date
- 2026-07-31
AI Technical Summary
Existing tilting pad bearings cannot effectively dissipate heat when mixed with lubricant, leading to frequent mechanical failures and difficulty in achieving tight tolerances.
Flexible support bearings with front edge grooves, manufactured by electrical discharge machining (EDM), directly supply low-temperature lubricant to the contact point between the rotating shaft and the high-temperature lubricant by setting grooves on the front edge of the bearing, forming a lubricant barrier and preventing heat retention.
It achieves tighter tolerance control and more consistent performance, reduces mechanical failures, and lowers the operating temperature of the rotating shaft.
Smart Images
Figure CN122480413A_ABST
Abstract
Description
Background Technology
[0001] Bearings reduce friction between moving parts and restrict relative motion in the desired direction. Mechanical systems such as rotating machines (e.g., motors, generators, compressors, etc.) use swivel bearings to allow shafts or axles to rotate freely about a fixed axis. Swivel bearings transfer axial and radial loads from the load source to the structure supporting the load source. Attached Figure Description
[0002] Specific embodiments are described with reference to the accompanying drawings. The same reference numerals used in different examples of the specification and drawings may indicate similar or identical items.
[0003] Figure 1 This is an isometric view of a drive system in a compressor assembly according to an exemplary embodiment of the present disclosure, the compressor assembly including an electrical discharge machined (EDM) bearing having a leading-edge groove (LEG).
[0004] Figure 2 This is based on exemplary embodiments of the present disclosure. Figure 1 The EDM bearing shown is a cross-sectional view taken along line 2-2.
[0005] Figure 3 This is based on exemplary embodiments of the present disclosure. Figure 1 The image shows a close-up of a cross-sectional view of the EDM bearing taken along line 3-3.
[0006] Figure 4 This is based on exemplary embodiments of the present disclosure. Figure 2 The EDM bearing shown is a partial cross-sectional view taken along line 4-4.
[0007] Figure 5 This is based on exemplary embodiments of the present disclosure. Figure 4 The enlarged view of the cross-section of the EDM bearing shown in circle 5.
[0008] Figure 6 This is based on exemplary embodiments of the present disclosure. Figure 1 The enlarged view of the cross section of the EDM bearing shown is taken along line 6-6.
[0009] Figure 7 This is a schematic diagram of a compression system employing an electrical discharge machining (EDM) bearing with a leading edge groove (LEG) according to an exemplary embodiment of the present disclosure. Detailed Implementation
[0010] Although the subject matter has been described using language specific to structural features and / or process operations, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms of implementing the claims.
[0011] Overview Rotating machines, such as compressor systems, use rotary bearings to reduce friction and distribute the load on the rotating shaft. For example, a rotary bearing in the drive system of a centrifugal compressor or rotary screw compressor may be configured to support the pinion shaft of the drive system.
[0012] Tilting pad journal bearings (TBJBs) are fluid film bearings that use a lubricant coating between the bearing and a rotating component (e.g., a rotating shaft). A TBJB may include a bent section or bearing shell connected to a pivot point of the bearing housing. A TBJB includes lubricant ports disposed between each pair of bearing shells. Typically, these bearing shells are assembled onto the bearing housing, resulting in an overlap of tolerances when these bearing shells are assembled to each other. Therefore, these bearings are difficult to achieve tighter tolerances and require more maintenance to prevent and correct mechanical failures. In a TBJB, the lubricant is delivered between the bearing shell pairs and the rotating shaft in a mixing chamber, where a high-temperature lubricant in contact with the bearing shells and shaft mixes with a low-temperature lubricant delivered through the lubricant ports to cool the high-temperature lubricant. However, this mixing of the high-temperature and low-temperature lubricants is not an efficient way to dissipate heat from the bearing shells.
[0013] This disclosure relates to a leading edge groove (LEG) bearing for a flexible bearing bush with electrically discharged (EDM) machining. The bearing housing includes a housing portion and a bush portion machined from the same housing. The bush portion includes a LEG disposed at the leading edge of the inner circumference of the respective bush. The LEG is configured to deliver lubricant to a rotating shaft supported by the bearing, wherein the lubricant is delivered directly between the respective bush and the rotating shaft, thereby reducing the operating temperature of the rotating shaft. Additionally, positioning the groove on the leading edge of the bush forms a lubricant barrier that prevents the ingress of high-temperature lubricant from adjacent bushes (which previously contacted the rotating shaft), thereby transferring heat away from the bushes.
[0014] The bearing bush portion comprises a flexible support bush machined from the common housing element of the bearing. EDM-machined bushes allow for tighter tolerances and minimize mechanical failures by eliminating additional components such as tilting bushes. Therefore, the bearings disclosed herein achieve more precise bearing clearances and more consistent performance.
[0015] Detailed description of exemplary embodiments refer to Figure 1 and Figure 7 The illustration shows a compressor system 100 having at least one compressor main unit 50 and a drive system 102. The drive system 102 includes a gearbox 108 configured to drive a rotational shaft 110 about a rotational axis 100X. In an embodiment, the gearbox 108 includes at least one pinion 104 and an electrical discharge machining (EDM) bearing 120 having a leading edge groove (LEG). The gearbox 108 may include a gearbox housing and a large gear, wherein the large gear is configured to drive at least one pinion 104.
[0016] EDM bearing 120 is configured to support rotation of shaft 110 while minimizing friction between shaft 110 and bearing 120. It should be understood that although the exemplary embodiment discusses EDM bearing 120 as part of drive system 102 in compressor system 100, EDM bearing 120 can be used in other applications using rotating shafts, such as in rotating machines like motors, generators, and pumps. In the illustrated exemplary embodiment, the bearing is a journal bearing.
[0017] EDM bearing 120 includes a bearing housing 122 and a sealing plate 112 disposed at a distal end 123 of the bearing housing 122. The bearing housing 122 includes an outer surface 116, an inner surface 118, a housing portion 124 (e.g., a portion of the bearing housing 122), and a bearing bush portion 126 (e.g., a portion of the bearing housing 122 including a bearing bush). The inner surface 118 of the bearing housing 122 is adjacent to the rotating shaft 110. Figure 1 As shown, the bearing housing 122 includes a lubrication ring 114 defined on the circumference of its outer surface 116. The lubrication ring 114 is fluidly connected to a gearbox port (not shown) of a lubricant cooling system 60 that supplies lubricant to the gearbox 108, thereby supplying lubricant to the EDM bearing 120.
[0018] The bearing portion 126 includes at least one flexible support bearing 128 machined as a single piece by electrical discharge machining (EDM), such that the flexible support bearing 128 is integral with the outer shell portion 124 of the bearing housing 122. A flexible pivot stem 125 machined between the outer shell portion 124 and the bearing portion 126 connects the two bearing portions (outer shell portion 124 and bearing portion 126) together. The flexible pivot stem 125 allows the flexible support bearing to dynamically support the rotating shaft 110 based on the load applied to the shaft during operation. In the illustrated embodiment, the bearing portion 126 includes four (4) flexible support bearings 128, with cavities 129 formed between pairs of flexible support bearings 128. In other embodiments (not shown), the bearing portion 126 may include one or more flexible support bearings 128 that generally surround and support the surface of the rotating shaft 110. For example, the bearing portion 126 may include two (2) flexible bearings 128, three (3) flexible bearings 128, five (5) flexible bearings 128, etc.
[0019] Reference Figure 3 and Figure 4 Lubricant overflowing from lubrication ring 114 is guided to shaft 110 through lubrication port 130. Lubrication port 130 includes housing channel 132 in housing portion 124, connecting nozzle 133, and bearing channel 134 in bearing portion 126. In embodiments, connecting nozzle 133 may include flexible materials, including but not limited to silicone, rubber, and / or other elastomers or flexible polymers. Connecting nozzle 133 may include, for example, Figure 3 The threaded connector shown may be connected between the lubrication ports 130 by an interference fit. In other embodiments, the nozzle 133 may be directly machined between the housing channel 132 and the bearing channel 134 using EDM.
[0020] As shown, each flexible support bearing 128 includes and defines a leading edge groove 140 in its inner surface 118, which is parallel to the axis of rotation 110X. The leading edge groove is fluidly connected to a corresponding lubrication port 130 via an opening 142. Upon overflow, the leading edge groove directly lubricates the rotating shaft 110 before the cooler lubricant entering the gearbox 108 mixes with the hotter lubricant already in contact with the flexible support bearing 128. The fresh lubricant provides a barrier to prevent the hotter lubricant from transferring between adjacent flexible support bearings 128. This direct supply of fresh lubricant inhibits thermal retention between the rotating shaft 110 and the inner surface 118 of the bearing 120. Specifically, in some embodiments, direct lubricant supply can partially reduce thermal retention between the rotating shaft 110 and the inner surface 118 of the bearing 120. In other embodiments, direct lubricant supply can completely prevent thermal retention between the rotating shaft 110 and the inner surface 118 of the bearing 120.
[0021] exist Figure 4 In the illustrated embodiment, the leading edge groove 140 on each flexible support bearing 128 has the same width and depth. However, in other embodiments, at least one leading edge groove 140 may have a different width and / or depth than the others. For example, a loaded flexible support bearing 128 or a bearing supporting most of the load on the rotating shaft 110 may have a wider and / or deeper leading edge groove 140 than an unloaded flexible support bearing 128 or a bearing not supporting most of the load on the rotating shaft 110.
[0022] like Figure 5 and Figure 6 As shown, the leading edge groove 140 extends toward the distal end 131 of the flexible support bearing 128. The leading edge groove 140 can open toward the distal end 131 of the flexible support bearing 128, allowing lubricant to flow through the flexible support bearing 128 and discharge through the leading edge groove 140 toward the distal end 123 of the bearing housing. The lubricant discharged through the distal end 131 of the flexible support bearing 128 returns to the gearbox 108 and is delivered to the lubricant cooling system 60. Figure 7 The fluid is cooled and recirculated to another location in the drive system 102 or compressor system 100.
[0023] As shown, the inner surface 118 of the EDM bearing 120 includes a sleeve 144 configured to reduce friction between the EDM bearing 120 and the rotating shaft 110. In embodiments, the sleeve 144 is formed of a material different from that of the bearing housing 122. For example, in one embodiment, the bearing housing 122 and the flexible support bushing 128 comprise steel (e.g., chromium steel, stainless steel, carbon steel), ceramics (e.g., silicon nitride), polymers, or combinations thereof, while the sleeve 144 comprises tin-based babbitt. In other embodiments, the babbitt may be another alloy comprising at least one of tin, copper, antimony, or combinations thereof. The sleeve 144 may be attached to the inner surface 118 of the bearing before the leading edge groove 140 is machined to the flexible support bushing 128. In other embodiments, the EDM bearing 120 does not include the sleeve 144. In other embodiments, sleeve 144 includes sleeve groove 146 that allows lubricant overflowing from front edge groove 140 to drain and flow freely toward sealing plate 112.
[0024] Refer again Figure 1 A sealing plate 112 is disposed at the distal end 131 of the flexible support bearing 128. The flexible support bearing is confined between two (2) sealing plates 112, wherein the sealing plates 112 are configured to prevent lubricant flowing in the flexible support bearing 128 from leaking from the bearing 120 before carrying away heat from the bearing 120. The sealing plates 112 also allow controlled discharge of lubricant flowing through the flexible support bearing 128. For example, in an embodiment, the inner radius R of the sealing plate 112 relative to the axis of rotation 110X is... SP The inner radius R of the flexible support bearing bush 128 relative to the axis of rotation 110X is greater than that of the bearing bush 128. PP This allows the lubricant to flow freely through the flexible support bearing 128 into the front edge groove 140 and out into the gearbox 108.
[0025] exist Figure 7 In the illustrated embodiment, the compressor system 100 includes four (4) compressor units 50. However, it should be understood that in other embodiments, the compressor system 100 may include fewer or more compressor units 50. It should also be understood that the EDM bearing 120 may be used in other applications, and is not limited to, the compressor system 100.
[0026] While the accompanying drawings and foregoing description have illustrated and described the subject matter of the invention in detail, these illustrations and descriptions should be considered exemplary rather than restrictive. It should be understood that only partial embodiments have been shown and described, and all changes and modifications consistent with the spirit of the subject matter of the invention are protected. When reading the claims, it should be understood that the use of terms such as “a,” “an,” “at least one,” or “at least a portion” does not imply that the claims are limited to a single item unless expressly specified in the claims. Unless otherwise specified or limited, the terms “connection” and “linkage” and their variations are used broadly to cover direct and indirect installation, connection, support, and coupling. Furthermore, “connection” and “linkage” are not limited to physical or mechanical connections or couplings.
Claims
1. An electrical discharge machining (EDM) bearing, the EDM bearing comprising: A housing extending about a rotation axis, the housing defining at least one lubricant port connected to the outer periphery of the housing and extending radially toward the rotation axis; EDM flexible support bearing bush, which is machined from the housing, is configured to provide support for a rotation axis rotating about the rotation axis in a first direction, and has a lubricant channel aligned with the lubricant port; as well as A leading edge groove is machined on the inner circumference of the EDM flexible support bearing and is in fluid communication with the lubricant channel, the leading edge groove being configured to deliver lubricant to the rotating shaft.
2. The EDM bearing according to claim 1, wherein, The front edge groove is provided on the front edge of the EDM flexible support bearing, and the lubricant is delivered directly between the rotating shaft and the EDM flexible support bearing.
3. The EDM bearing according to claim 1, wherein, The lubricant channel includes a housing channel defined through the housing portion of the housing and a bearing channel defined through the EDM flexible support bearing, wherein the housing channel and the bearing channel are connected by a connecting nozzle.
4. The EDM bearing according to claim 3, wherein, The connecting nozzle is directly machined into the EDM flexible support bearing bush.
5. The EDM bearing according to claim 1, wherein, The EDM bearing also includes a sealing plate configured to retain the lubricant flowing through the EDM flexible support bearing bush.
6. The EDM bearing according to claim 5, wherein, The inner radius of the sealing plate relative to the axis of rotation is greater than the inner radius of the EDM flexible support bearing relative to the axis of rotation.
7. The EDM bearing according to claim 5, wherein, The EDM bearing also includes a sleeve disposed between the EDM flexible support bearing shell and the rotating shaft.
8. The EDM bearing according to claim 7, wherein, The sleeve includes a sleeve groove aligned with the front edge groove, the sleeve groove being configured to discharge the lubricant overflowing from the front edge groove toward the sealing plate.
9. A compressor system, the compressor system comprising: A compressor main unit, the compressor main unit being configured to rotate about a rotation axis; and A drive system configured to drive the compressor main unit, the drive system comprising: A rotating shaft, which is connected to the compressor main unit, and The electrical discharge machining (EDM) bearing according to any one of claims 1 to 8, wherein the EDM bearing is configured to support the rotating shaft.