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CN-121993265-A - Sealing gas circuit and sealing system

CN121993265ACN 121993265 ACN121993265 ACN 121993265ACN-121993265-A

Abstract

The invention provides a sealing gas path, which extends between a low-pressure end of a gas compressor and a sealing cavity, and comprises a high-speed shaft inner channel, wherein the high-speed shaft inner channel is limited in the high-speed shaft by the pipe wall of the high-speed shaft, and the inner side surface of the pipe wall is provided with a pressurizing structure protruding inwards.

Inventors

  • ZHANG XIAOLIN
  • HUANG XINFENG
  • WANG YIJUN
  • CHAI JUNSHENG

Assignees

  • 中国航发商用航空发动机有限责任公司

Dates

Publication Date
20260508
Application Date
20241105

Claims (16)

  1. 1. The sealing gas circuit is characterized by extending between a low-pressure end of the gas compressor and a sealing cavity, and comprises a high-speed shaft inner channel; The high-speed shaft inner channel is limited in the high-speed shaft by the pipe wall of the high-speed shaft, and the inner side surface of the pipe wall of the high-speed shaft is provided with an inward-protruding pressurizing structure.
  2. 2. The seal air path of claim 1, wherein the seal air path is connected between a terminal bleed port of the low pressure compressor and a seal cavity bleed port.
  3. 3. The seal air path of claim 1, wherein the length of the pressurization structure extending axially along the high speed shaft is equal to the axial length of the high speed shaft.
  4. 4. The seal of claim 1 wherein the projected area of said plenum structure on said high speed shaft cross section is less than two-fifths of the projected area of said high speed shaft inner passage on said high speed shaft cross section.
  5. 5. The seal of claim 1 wherein the projected area of the area swept by the pressurization structure as it rotates with the high speed shaft on the high speed shaft cross section is greater than two-thirds of the projected area of the channel in the high speed shaft on the high speed shaft cross section.
  6. 6. The sealed air passage according to claim 1, wherein the pressurizing structure includes a first end and a second end, the first end being fixed to the inner side surface of the pipe wall, the second end being an end of the pressurizing structure radially away from the first end along the high-speed shaft; the second end and the central axis of the high-speed shaft are provided with a first gap in the radial direction of the high-speed shaft.
  7. 7. A seal air passage according to claim 2 or3, wherein a plurality of said supercharging formations are circumferentially spaced along said high speed axis on said inner side of said tube wall.
  8. 8. The sealed air passage according to claim 7, wherein the pressurization structure includes a first end and a second end, the first end being fixed to the inner side of the pipe wall, the second end being an end of the pressurization structure radially away from the first end along the high speed axis; The second ends of the plurality of booster structures are interconnected as a unit.
  9. 9. The sealed air passage according to claim 1, wherein the high-speed shaft has a low-speed shaft therein, the high-speed shaft and the low-speed shaft are coaxially arranged, and the high-speed shaft inner passage is defined between a pipe wall of the high-speed shaft and a pipe wall of the low-speed shaft; The supercharging structure comprises a first end and a second end, the first end is fixed on the inner side surface of the pipe wall of the high-speed shaft, and the second end is one end, far away from the first end, of the supercharging structure along the radial direction of the high-speed shaft; the second end and the pipe wall of the low-speed shaft are provided with a second clearance in the radial direction of the high-speed shaft.
  10. 10. The seal gas circuit of claim 9, wherein a ratio of a radial dimension of the second gap to a radial distance between the low speed shaft and the high speed shaft is greater than or equal to 0.2 and less than 0.5.
  11. 11. The seal air path of claim 1 wherein said plenum structures are distributed along a radial extension of said high speed shaft.
  12. 12. The seal air path of claim 1 wherein said pressurization structure has an angle of inclination along a direction of rotation of said high speed shaft.
  13. 13. The sealed air passage according to claim 1, wherein the pressurizing structure includes a first end and a second end, the first end being fixed to the inner side surface of the pipe wall, the second end being an end of the pressurizing structure away from the first end in a radial direction of the high-speed shaft; The first end has a width that is greater than a width of the second end, wherein the width is a dimension along the high speed axis in a circumferential direction.
  14. 14. The sealed air passage according to claim 1, wherein the pressurizing structure includes a first end and a second end, the first end being fixed to the inner side surface of the pipe wall, the second end being an end of the pressurizing structure away from the first end in a radial direction of the high-speed shaft; The portion of the pressurization structure having a minimum width is located between the first end and the second end, wherein the width is a dimension along the high speed axis in a circumferential direction.
  15. 15. The sealed off air path of claim 14, wherein a ratio of the minimum width over the pressurization structure to a maximum width over the pressurization structure is greater than two-thirds.
  16. 16. A sealing system comprising the sealing gas path of any one of claims 1-15; the sealing system further comprises an air bleed port, a disc cavity channel in the air compressor and a sealing cavity, wherein the air bleed port is arranged at the low-pressure end of the air compressor, and the sealing cavity is positioned at the periphery of the bearing cavity; the air guiding opening, the disc cavity channel, the high-speed shaft channel and the sealing cavity are sequentially communicated and used for conveying sealing air flow.

Description

Sealing gas circuit and sealing system Technical Field The specification relates to aeroengine bearing chamber sealing technology, especially relates to a sealing gas circuit and sealing system. Background In order to ensure safe operation of the aeroengine bearing, lubricating oil needs to be supplied into the bearing cavity. Because the boundary of the bearing cavity is the joint surface of the rotor and the stator, a leakage gap exists, and a comb tooth sealing structure is generally adopted to avoid oil leakage. If the lubricating oil leaks, the lubricating oil consumption is increased, the economy of the engine is reduced, and on the other hand, the explosion can occur in a high-temperature area, so that the safety of the engine is affected. The comb teeth sealing structure is a non-contact dynamic sealing structure which utilizes the sudden expansion and the sudden contraction of the passage to increase the airflow resistance so as to limit the leakage of fluid. In order to ensure the sealing performance of the sealing structure of the comb teeth, the pressure of the sealing cavity positioned at the periphery of the bearing cavity is required to be larger than the pressure in the bearing cavity, and a certain pressure difference exists between the inside and the outside of the bearing cavity. Meanwhile, in order to ensure the safe operation of the bearing in the bearing cavity, the temperature of sealing air flow entering the bearing cavity from the sealing cavity is required to be not more than a limit value, so that the combustion and coking of lubricating oil in the bearing cavity are avoided. The sealing air flow temperature is required to be not more than a limit value while a certain pressure difference exists between the inside and the outside of the bearing cavity, and a certain contradiction exists between the sealing air flow temperature and the limit value. In order to ensure the pressure difference between the inside and the outside of the bearing cavity, the sealing air flow is led from the high-pressure end of the air compressor, which can lead to the higher temperature of the sealing air flow, and in order to ensure that the temperature of the sealing air flow does not exceed a limit value, the sealing air flow is led from the low-pressure end of the air compressor, which can inevitably lead to insufficient pressure difference between the inside and the outside of the bearing cavity. Therefore, how to design the sealing air path for sealing the air flow to ensure the sealing performance and the safe operation of the bearing is a considerable technical problem. Disclosure of Invention The invention aims at providing a sealing gas circuit capable of guaranteeing the temperature and the pressure of sealing gas flow. The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. One embodiment of the invention provides a sealing gas circuit, which extends between a low-pressure end of a gas compressor and a sealing cavity and comprises a high-speed shaft inner channel, wherein the high-speed shaft inner channel is limited in the high-speed shaft by the pipe wall of the high-speed shaft, and an inward-protruding pressurizing structure is arranged on the inner side surface of the pipe wall of the high-speed shaft. In some embodiments, the seal gas path is connected between the terminal bleed port of the low pressure compressor and the seal cavity bleed port. In some embodiments, the length of the pressurization structure extending axially along the high speed shaft is equal to the axial length of the high speed shaft. In some embodiments, the projected area of the plenum structure on the high speed axis cross section is less than two-fifths of the projected area of the channels in the high speed axis on the high speed axis cross section. In some embodiments, the projected area of the area swept by the boost structure with rotation of the high speed shaft on the high speed shaft cross section is greater than two-thirds of the projected area of the passage in the high speed shaft on the high speed shaft cross section. In some embodiments, the pressurization structure comprises a first end and a second end, wherein the first end is fixed on the inner side surface of the pipe wall, the second end is one end of the pressurization structure, which is far away from the first end along the radial direction of the high-speed shaft, and the second end and the central axis of the high-speed shaft are provided with a first gap along the radial direction of the high-speed shaft. In some embodimen