Oil seal structure of steam turbine
By setting up an air supply channel and an air inlet in the turbine oil seal structure and using nitrogen positive pressure sealing, the problem of poor sealing of the turbine bearing cavity was solved, achieving a better sealing effect, preventing lubricating oil leakage and steam pollution, and improving the safety and stability of the machine.
Patent Information
- Application Number
- CN202422759837.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-13
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-13
AI Technical Summary
Poor sealing of the turbine bearing cavity leads to lubricating oil leakage and steam contamination of the lubricating oil, affecting the safe and stable operation of the machine.
Design a turbine oil seal structure with an air supply channel and an air inlet on the cover. Use nitrogen to form a positive pressure seal to prevent lubricating oil leakage and steam from entering the bearing cavity.
It achieves better sealing, prevents lubricating oil leakage and steam pollution, and improves the safe and stable operation of the steam turbine.
Smart Images
Figure CN223523794U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of steam turbines, and particularly relates to a steam turbine oil seal structure. BACKGROUND
[0002] During operation of a steam turbine, due to the high-speed rotating characteristics of the main shaft, the bearing cavity cannot be made into a completely sealed space. After the continuously supplied lubricating oil contacts the main shaft, it will present an irregular moving track, which causes frequent oil leakage of the bearing body. In addition, the bearing cavity is beside the cylinder, and steam will leak out during operation of the steam turbine. This part of steam may enter the bearing cavity, thereby polluting the lubricating oil, which poses a threat to safe and stable operation of the steam turbine. Therefore, it is necessary to solve the above technical problems. CONTENT OF THE UTILITY MODEL
[0003] The purpose of the embodiment of the application is to provide a steam turbine oil seal structure to solve the technical problem of poor sealing effect of the bearing cavity of the steam turbine in the prior art.
[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the application is to provide a steam turbine oil seal structure, comprising:
[0005] A steam turbine shaft;
[0006] A bearing body connected to the steam turbine shaft and used for supporting the steam turbine shaft;
[0007] A cover horizontally and radially split into two pieces, movably sleeved on the steam turbine shaft and connected with the bearing body, the cover cooperating with the bearing body and the steam turbine shaft to form a bearing cavity for accommodating lubricating oil, the cover further forming a gas feeding passage extending to the gap between the cover and the steam turbine shaft, the bearing body further forming an air inlet communicated with the gas feeding passage and an air outlet communicated with the bearing cavity.
[0008] Optionally, the gas feeding passage is uniformly and spacedly provided with multiple groups around the central axis of the steam turbine shaft.
[0009] Optionally, the cover is recessed on the surface around the steam turbine shaft to form a plurality of annular grooves coaxial with the steam turbine shaft;
[0010] The plurality of annular grooves are uniformly distributed along the axial direction of the steam turbine, and at least one annular groove is communicated with the gas feeding passage.
[0011] Optionally, the cover is provided with a counterbore communicated with the bearing cavity, and the counterbore is further communicated with the annular groove between the gas feeding passage and the bearing cavity.
[0012] Optionally, the steam turbine shaft is provided with a flange plate protruding along the radial direction of the steam turbine shaft, and the flange plate is located in the bearing cavity.
[0013] Optionally, the flange plate forms a groove coaxial with the turbine shaft on the surface away from the turbine shaft;
[0014] The cover forms a first extension parallel to the turbine shaft and a second extension connected to the first extension and perpendicular to the turbine shaft, at least a part of the second extension extends into the groove.
[0015] Optionally, the first extension forms a through backflow hole, the counterbore communicates with the bearing cavity through the backflow hole, and the backflow hole is located at the lowest radial position of the first extension.
[0016] Optionally, corresponding anti-rotation pin holes are formed on the cover and the bearing body respectively, and the anti-rotation pin holes are perpendicular to the axial direction of the turbine shaft.
[0017] Optionally, the turbine oil seal structure further comprises a steam baffle coaxial with the turbine shaft, and the steam baffle is connected to the side of the cover away from the bearing cavity.
[0018] Optionally, the turbine oil seal structure further comprises a distance block arranged between the steam baffle and the cover, and the steam baffle is connected to the cover through the distance block and is arranged in a spaced manner with the cover.
[0019] The turbine oil seal structure provided by the present application has the following beneficial effects: compared with the prior art, in the turbine oil seal structure provided by the present application, the cover is provided with a gas supply channel extending to the gap between the cover and the bearing body, and the bearing body is provided with an air inlet communicating with the gas supply channel, so that nitrogen gas can enter the gap between the cover and the bearing body through the air inlet on the bearing body and the gas supply channel on the cover. In this way, the lubricating oil in the bearing cavity cannot leak through the gap between the cover and the bearing body, and external steam cannot enter the bearing cavity through the gap between the cover and the bearing body, so that the turbine oil seal structure provided by the present application can form a better sealing effect, which is much better than the prior art. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0021] Figure 1 It is a schematic diagram of the overall structure of the turbine oil seal structure in the embodiments of the present application.
[0022] Figure 2 Fig. 1 is a schematic view of a front structure of a cover in an embodiment of the present application;
[0023] Figure 3 Fig. 2 is a sectional view along line A-A in Fig. 1; Figure 2
[0024] Figure 4 Fig. 3 is a schematic view of a rear structure of the cover in the embodiment of the present application.
[0025] In the drawings, reference numerals: 101, turbine shaft; 102, bearing body; 103, cover; 104, bearing cavity; 105, air feeding passage; 106, air inlet; 107, air outlet; 108, annular groove; 109, counterbore; 110, flange plate; 111, recess; 112, first extension; 113, second extension; 114, backflow hole; 115, anti-rotation pin hole; 116, steam baffle; 117, distance block; 118, clamping groove. DETAILED DESCRIPTION
[0026] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.
[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0028] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0029] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.
[0030] Please refer to Figures 1 to 4 The application provides a steam turbine oil seal structure.
[0031] The bearing body 102 is connected to the steam turbine shaft 101 and is used for supporting the steam turbine shaft 101; the cover 103 is horizontally and radially split into two parts, is movably sleeved on the steam turbine shaft 101 and is connected to the bearing body 102, the cover 103 cooperates with the bearing body 102 and the steam turbine shaft 101 to form a bearing cavity 104 used for containing lubricating oil, the cover 103 further forms a gas feeding channel 105 extending to the gap between the cover 103 and the steam turbine shaft 101, and the bearing body 102 forms an air inlet 106 communicated with the gas feeding channel 105 and an air outlet 107 communicated with the bearing cavity 104. It can be understood that, in order to facilitate installation, the bearing body 102 can be provided with two parts which are detachably connected in actual production, the bearing body 102 is designed as a structure which is horizontally and radially split into two parts in the embodiment, and a clamping groove 118 matched with the outer edge of the cover 103 is formed on the bearing body 102, in the assembly process, the lower half of the bearing body 102 is first installed on the steam turbine shell, then the lower half of the cover 103 is assembled into the lower half of the bearing body 102, the outer edge of the cover 103 is clamped into the clamping groove 118, and a rotation prevention pin is punched into a rotation prevention pin hole 115 (described later) to position the cover 103, then the upper half of the cover 103 is matched with the lower half of the cover 103, and finally the upper half of the bearing body 102 is installed and fixed, and the specific operation of the installation and connection can be achieved by using the existing steam turbine technology, and thus the detailed description is not given herein.
[0032] According to the above structure provided in the embodiment, in the steam turbine oil seal structure provided in the embodiment, since the cover 103 is provided with the gas feeding channel 105 extending to the gap between the cover 103 and the steam turbine shaft 101, and the bearing body 102 is provided with the air inlet 106 communicated with the gas feeding channel 105, the nitrogen can enter the gap between the cover 103 and the steam turbine shaft 101 through the air inlet 106 on the bearing body 102 and the gas feeding channel 105 on the cover 103, and the nitrogen positive pressure is formed in the rotating and matching gap between the cover 103 and the steam turbine shaft 101, so that the lubricating oil in the bearing cavity 104 cannot leak through the gap between the cover 103 and the bearing body 102, and the external steam cannot enter the bearing cavity 104 through the gap between the cover 103 and the bearing body 102, so that the steam turbine oil seal structure provided in the embodiment can form a better sealing effect, which is much better than the prior art. It can be understood that the nitrogen entering the bearing cavity 104 can also be discharged from the air outlet on the bearing body 102 to keep the nitrogen positive pressure in the rotating and matching gap between the cover 103 and the steam turbine shaft 101 stable.
[0033] In another embodiment of the application, please refer to Figures 1 to 4The air feeding passages 105 are evenly spaced around the central axis of the turbine shaft 101. According to the above structure provided in the embodiment, the air feeding passages 105 arranged around the turbine shaft 101 can form a better sealing effect for the turbine oil seal structure in the embodiment.
[0034] In another embodiment of the present application, referring to Figures 1 to 4 The cover 103 is recessed on the surface around the turbine shaft 101 to form a plurality of annular grooves 108 coaxial with the turbine shaft 101; the annular grooves 108 are evenly distributed along the axial direction of the turbine structure, and at least one annular groove 108 is communicated with the air feeding passage 105. According to the above structure provided in the embodiment, the annular grooves 108 can form an annular groove structure on the side surface of the cover 103 facing the turbine shaft 101, thereby forming a plurality of chambers with a positive pressure of nitrogen, which can further prevent the lubricating oil in the bearing cavity 104 from leaking; on the other hand, the nitrogen can stay in the rotating gap between the cover 103 and the turbine shaft 101 more fully, which is conducive to further improving the sealing effect of the turbine oil seal structure in the embodiment.
[0035] In another embodiment of the present application, referring to Figures 1 to 4 The cover 103 is provided with a counterbore 109 communicated with the bearing cavity 104, and the counterbore 109 is further communicated with the annular groove 108 between the air feeding passage 105 and the bearing cavity 104. According to the above structure provided in the embodiment, the counterbore 109 can collect the lubricating oil entering the annular groove 108 between the air feeding passage 105 and the bearing cavity 104 and make it flow back to the bearing cavity 104, which is conducive to further improving the sealing effect of the turbine oil seal structure in the embodiment.
[0036] In another embodiment of the present application, referring to Figures 1 to 4 The turbine shaft 101 is formed with a flange 110 protruding in the radial direction thereof, and the flange 110 is located in the bearing cavity 104. According to the above structure provided in the embodiment, the centrifugal force generated when the turbine shaft 101 rotates at a high speed can effectively throw the lubricating oil on the surface of the turbine shaft 101 radially, reducing the amount of lubricating oil entering the cover 103 axially along the surface thereof, i.e., the flange 110 formed on the turbine shaft 101 can prevent most of the lubricating oil from spreading along the axial direction of the turbine shaft 101, which is conducive to further improving the sealing effect of the turbine oil seal structure in the embodiment.
[0037] In another embodiment of the present application, referring to Figures 1 to 4, the flange 110 forms a groove 111 coaxial with the turbine shaft 101 on the surface away from the turbine shaft 101; the cover 103 forms a first extension 112 parallel to the turbine shaft 101 and a second extension 113 connected to the first extension 112 and perpendicular to the turbine shaft 101, at least a part of the second extension 113 extends into the groove 111. According to the above structure provided in the embodiment, the first extension 112 and the second extension 113 can make the path of the lubricating oil from the bearing cavity 104 to the gap between the cover 103 and the bearing body 102 more tortuous, which is conducive to further improving the sealing effect of the steam turbine oil seal structure in the embodiment.
[0038] In another embodiment of the present application, please refer to Figures 1 to 4 , the first extension 112 forms a through backflow hole 114, the counterbore 109 is communicated with the bearing cavity 104 through the backflow hole 114, and here, the backflow hole 114 is located at the lowest radial position of the first extension 112. According to the above structure provided in the embodiment, the backflow hole 114 formed on the first extension 112 can make the lubricating oil in the counterbore 109 flow back to the bearing cavity 104 more smoothly, which is conducive to further improving the sealing effect of the steam turbine oil seal structure in the embodiment.
[0039] In another embodiment of the present application, please refer to Figures 1 to 4 , the cover 103 and the bearing body 102 respectively form corresponding anti-rotation pin holes 115, the anti-rotation pin holes 115 are perpendicular to the axial direction of the turbine shaft 101. According to the above structure provided in the embodiment, the anti-rotation pin inserted into the anti-rotation pin hole 115 can effectively limit the rotation of the cover 103 around the central axis of the turbine shaft 101, which is conducive to further improving the sealing effect of the steam turbine oil seal structure in the embodiment.
[0040] In another embodiment of the present application, please refer to Figures 1 to 4 , the steam turbine oil seal structure further comprises a steam baffle 116 coaxial with the turbine shaft 101, the steam baffle 116 is connected to the side of the cover 103 away from the bearing cavity 104. According to the above structure provided in the embodiment, the steam baffle 116 connected to the cover 103 can more effectively prevent the steam generated by the steam turbine from entering the bearing cavity 104, which is conducive to further improving the sealing effect of the steam turbine oil seal structure in the embodiment.
[0041] In another embodiment of the present application, please refer to The steam turbine oil seal structure further comprises a distance block 117 arranged between the steam baffle 116 and the cover 103, and the steam baffle 116 is connected to the cover 103 through the distance block 117 and is arranged in a spaced manner with the cover 103. According to the above structure provided in the embodiment, the steam baffle 116 arranged in a spaced manner with the cover 103 can form a better blocking effect on steam, which is conducive to further improving the sealing effect of the steam turbine oil seal structure in the embodiment.
[0042] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A steam turbine oil seal structure, characterized by, The steam turbine oil seal structure comprises: a steam turbine shaft (101); a bearing body (102) connected to the steam turbine shaft (101) and used for supporting the steam turbine shaft (101); a cover (103) horizontally split into two parts, movably sleeved on the steam turbine shaft (101) and connected to the bearing body (102), the cover (103) cooperating with the bearing body (102) and the steam turbine shaft (101) to form a bearing cavity (104) for containing lubricating oil, and the cover (103) further forms a gas feeding passage (105) extending to the gap between the cover (103) and the steam turbine shaft (101), and the bearing body (102) forms an air inlet (106) communicated with the gas feeding passage (105) and an air outlet (107) communicated with the bearing cavity (104).
2. The steam turbine oil seal structure according to claim 1, wherein: the gas feeding passage (105) is evenly spaced in multiple groups around the central axis of the steam turbine shaft (101).
3. The steam turbine oil seal structure according to claim 2, wherein: the cover (103) is recessed on the surface surrounding the steam turbine shaft (101) to form a plurality of annular grooves (108) coaxial with the steam turbine shaft (101); the plurality of annular grooves (108) are evenly distributed along the axial direction of the steam turbine, and at least one of the annular grooves (108) is communicated with the gas feeding passage (105).
4. The steam turbine oil seal structure according to claim 3, wherein: the cover (103) is provided with a counterbore (109) communicated with the bearing cavity (104), and the counterbore (109) is further communicated with the annular groove (108) between the gas feeding passage (105) and the bearing cavity (104).
5. The steam turbine oil seal structure according to claim 4, wherein: the steam turbine shaft (101) is formed with a flange (110) protruding in the radial direction of the steam turbine shaft (101), and the flange (110) is located in the bearing cavity (104).
6. The steam turbine oil seal structure according to claim 5, wherein: the flange (110) is formed with a groove (111) coaxial with the steam turbine shaft (101) on the surface away from the steam turbine shaft (101); the cover (103) is formed with a first extension (112) parallel to the steam turbine shaft (101) and a second extension (113) connected to the first extension (112) and perpendicular to the steam turbine shaft (101), and at least a portion of the second extension (113) extends into the groove (111).
7. The steam turbine oil seal structure according to claim 6, wherein: the first extension (112) is formed with a return hole (114) extending therethrough, the counterbore (109) is communicated with the bearing cavity (104) through the return hole (114), and the return hole (114) is located at the lowest position in the radial direction of the first extension (112).
8. The steam turbine oil seal structure according to claim 1, wherein: Corresponding anti-rotation pin holes (115) are formed on the cover (103) and the bearing body (102) respectively, and the anti-rotation pin holes (115) are perpendicular to the axial direction of the steam turbine shaft (101).
9. The steam turbine oil seal structure of claim 1, wherein: The steam turbine oil seal structure further comprises a steam baffle (116) coaxial with the steam turbine shaft (101), and the steam baffle (116) is connected to the side of the cover (103) away from the bearing cavity (104).
10. The steam turbine oil seal structure of claim 9, wherein: The steam turbine oil seal structure further comprises a distance block (117) arranged between the steam baffle (116) and the cover (103), and the steam baffle (116) is connected to the cover (103) through the distance block (117) and is arranged in a spaced manner with the cover (103).