Bearing common cavity lubrication and sealing structure and aircraft engine

Abstract

The present invention discloses a bearing common cavity lubrication and sealing structure, including a rotating shaft, a high-speed rotor for transmitting high speed and a clearance match with the rotating shaft, a front bearing seat assembly for fixing in a casing and supporting the high-speed rotor, a low-speed rotor for transmitting low speed and a rear bearing seat assembly for fixing in a casing and supporting the low-speed rotor, the rotating shaft, the high-speed rotor, the front bearing seat assembly, the rear bearing seat assembly and the low-speed rotor enclose a bearing cavity for installing multiple bearings, a lubrication assembly is arranged in the bearing cavity, the end of the front bearing seat assembly away from the rear bearing seat assembly includes a double-stage floating ring graphite sealing structure sleeved on the outside of the high-speed rotor, and the end of the rear bearing seat assembly away from the front bearing seat assembly includes a single-stage floating ring graphite sealing structure sleeved on the outside of the low-speed rotor. In addition, the present invention also discloses an aircraft engine.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engines, and in particular, to a bearing common cavity lubrication and sealing structure. In addition, the present invention also relates to an aircraft engine comprising the bearing common cavity lubrication and sealing structure. Background Art

[0002] At present, the bearing lubrication and sealing structure of aircraft engines are Figure 1 As shown, a nozzle jet is usually used to lubricate the bearing, and a grate seal device is used at the front and rear of the bearing cavity to seal the lubricating oil and prevent excessive high-temperature and high-pressure sealing gas from entering the bearing cavity. However, during the operation of the aircraft engine, since there is no follow-up effect between the rotor and the stator in the grate seal device, the vibration and deviation of the rotor cause the grate tooth tip and coating to wear, resulting in an irreversible permanent increase in the gap, which greatly reduces the reliability and service life of the aircraft engine. Moreover, most gas turbine engines are dual-rotor or even triple-rotor structures, with a large number of bearings and compact spatial distribution. Each bearing needs to include a set of lubricating oil lubrication and inter-axial sealing of the front and rear bearing cavities, and needs to be configured with an independent oil supply and return oil structure, which increases the load and complexity of the accessory lubrication system. At the same time, the number of parts in the structural layout is large, the space occupied is large, and the assembly is complex, which does not meet the requirements of high reliability, high performance and high service life of aircraft engines. Summary of the invention

[0003] The invention provides a bearing common cavity lubrication and sealing structure and an aero-engine, so as to solve the technical problems of low reliability, complex structure and short service life of the existing aero-engine.

[0004] According to one aspect of the present invention, a bearing common cavity lubrication and sealing structure is provided, comprising a rotating shaft, a high-speed rotor for transmitting high speed and having clearance with the rotating shaft, a front bearing seat assembly for fixing in a casing and rotatably supporting the high-speed rotor, a low-speed rotor for transmitting low speed and fixedly connected to the rotating shaft, and a rear bearing seat assembly for fixing in the casing and rotatably supporting the low-speed rotor. The rotating shaft, the high-speed rotor, the front bearing seat assembly, the rear bearing seat assembly and the low-speed rotor enclose a bearing cavity for mounting a plurality of bearings, a lubrication assembly for spraying lubricating oil to lubricate the plurality of bearings is arranged in the bearing cavity, the end of the front bearing seat assembly away from the rear bearing seat assembly comprises a double-stage floating ring graphite sealing structure sleeved outside the high-speed rotor for introducing high-temperature and high-pressure gas and low-temperature and low-pressure gas to seal the front end of the bearing cavity, and the end of the rear bearing seat assembly away from the front bearing seat assembly comprises a single-stage floating ring graphite sealing structure sleeved outside the low-speed rotor for introducing low-temperature and low-pressure gas to seal the rear end of the bearing cavity.

[0005] As a further improvement of the above technical solution:

[0006] Furthermore, the front bearing seat assembly includes a front bearing which is sleeved on the outside of the high-speed rotor and axially abuts against the double-stage floating ring graphite sealing structure, a front locking member which is sleeved on the high-speed rotor and axially abuts against the front bearing and is used to axially tighten and fix the inner ring of the front bearing, a front elastic support which is sleeved on the outside of the front bearing and axially abuts against the front bearing and is used to support the front bearing, a front bearing seat which is connected to the front elastic support and axially abuts against the front bearing and is used to axially limit the front bearing within the front elastic support, and a front sealing shell which is integrally formed with the front bearing seat and is used to be fixed in the casing.

[0007] Furthermore, the double-stage floating ring graphite sealing structure includes a front sealing track which is sleeved outside the high-speed rotor and axially abuts against the high-speed rotor, a first front graphite ring which is sleeved outside the front sealing track and axially abuts against the front bearing seat and is used for radial floating to achieve floating sealing, a second front graphite ring which is sleeved outside the front sealing track and is used for radial floating to achieve floating sealing, a mounting sleeve which is sleeved outside the first front graphite ring and axially abuts against the second front graphite ring and is used for axially limiting the second front graphite ring in the front bearing seat, a front outer clamping ring which is radially plug-fitted with the front bearing seat and axially abuts against the mounting sleeve and is used for axially limiting the mounting sleeve in the front bearing seat, and a front retaining member which is radially plug-fitted with the mounting sleeve and axially abuts against the first front graphite ring and is used for axially limiting the first front graphite ring in the front bearing seat.

[0008] Further, the front retaining member includes a front inner retaining ring plugged into the mounting bushing, a first front corrugated spring fixedly connected to the front inner retaining ring, and a first front gasket fixedly connected to the first front corrugated spring and axially abutting against the first front graphite ring; and / or the mounting bushing includes a bushing body sleeved outside the first front graphite ring, a second front corrugated spring fixedly connected to the bushing body, and a second front gasket fixedly connected to the second front corrugated spring and axially abutting against the second front graphite ring.

[0009] Furthermore, the front bearing seat is provided with a front limiting boss which extends radially inward and abuts against the front bearing axially for axially limiting the outer ring of the front bearing; and / or the front bearing seat assembly also includes a front fastener which passes through the front elastic support to be connected to the front bearing seat and is used to fix the front elastic support in the front bearing seat.

[0010] Furthermore, the rear bearing seat assembly includes a rear bearing which is sleeved on the outside of the low-speed rotor and axially abuts against the single-stage floating ring graphite sealing structure, a bearing spacer sleeve which is sleeved on the outside of the low-speed rotor and axially abuts against the rear bearing, a middle bearing which is sleeved on the outside of the low-speed rotor and axially abuts against the bearing spacer sleeve, a middle locking piece which is sleeved on the low-speed rotor and axially abuts against the middle bearing and is used to axially tighten and fix the inner ring of the middle bearing, a rear elastic support, a rear bearing seat which is connected to the rear elastic support and axially abuts against the rear bearing and is used to axially limit the rear bearing within the rear elastic support, and a rear sealing shell which is integrally formed with the rear bearing seat and is fixed in the casing, the rear elastic support is simultaneously sleeved on the outside of the middle bearing and the rear bearing, and axially abuts against the middle bearing and the rear bearing respectively for simultaneously providing radial support and axial limiting to the middle bearing and the rear bearing.

[0011] Furthermore, the single-stage floating ring graphite sealing structure includes a rear sealing track which is sleeved outside the low-speed rotor and axially abuts against the low-speed rotor, a rear graphite ring which is sleeved outside the rear sealing track and is used for radial floating to achieve floating sealing, and a rear clamping member which is plugged into the rear bearing seat and is used to axially limit the rear graphite ring in the rear bearing seat.

[0012] Furthermore, the rear retaining member includes a rear clamping ring plugged into the rear bearing seat, a rear corrugated spring fixedly connected to the rear clamping ring, and a rear gasket fixedly connected to the rear corrugated spring and axially abutting against the rear graphite ring.

[0013] Furthermore, the lubrication assembly includes an oil nozzle arranged in the bearing cavity and axially abutting against the middle bearing, a middle fastener passing through the oil nozzle and fixedly connected to the rear bearing seat for fixing the oil nozzle in the bearing cavity, an oil inlet opened in the rear bearing seat and connected to the oil nozzle, an oil inlet passage connected to the oil inlet for connecting to an oil pump, and a one-way valve arranged on the oil inlet passage for closing the oil inlet passage at a preset speed.

[0014] According to another aspect of the present invention, there is also provided an aircraft engine, which includes the above-mentioned bearing common cavity lubrication and sealing structure.

[0015] The present invention has the following beneficial effects:

[0016] The bearing common cavity lubrication and sealing structure of the present invention has a high-speed rotor and a rotating shaft clearance fit and is used to transmit a high speed, a front bearing seat assembly is fixed in the casing and rotatably supports the high-speed rotor, a low-speed rotor is fixedly connected to the rotating shaft and is used to transmit a low speed, and a rear bearing seat assembly is fixed in the casing and rotatably supports the high-speed rotor. A bearing cavity for installing multiple bearings is formed by enclosing the rotating shaft, the high-speed rotor, the front bearing seat assembly, the rear bearing seat assembly and the low-speed rotor, and then the multiple bearings are lubricated by a lubrication assembly arranged in the bearing cavity. Multiple bearings only need one lubrication assembly to achieve lubrication, which greatly reduces the parts required for lubrication, and has a compact structure, small space occupation and high reliability. The front end of the bearing cavity is sealed by a double-stage floating ring graphite sealing structure to prevent lubricating oil from leaking through the front end of the bearing cavity to the outside of the bearing cavity, and the double-stage floating ring graphite sealing structure can simultaneously introduce high-temperature and high-pressure gas The bearing cavity is sealed by the body and low-temperature and low-pressure gas, and the high-temperature and high-pressure gas is neutralized by introducing low-temperature and low-pressure gas to prevent excessive high-temperature and high-pressure from entering the bearing cavity and affecting the cavity pressure. The rear end of the bearing cavity is sealed by a single-stage floating ring graphite sealing structure to prevent the lubricating oil from leaking into the bearing cavity through the rear end of the bearing cavity. The floating ring graphite sealing structure adapts to the rotor eccentricity through radial floating to prevent the sealing gap from permanently increasing, thereby extending the service life and reducing the lubricating oil leakage rate. This solution realizes the common cavity lubrication of multiple bearings through the coordinated cooperation of the rotating shaft, high-speed rotor, front bearing assembly, low-speed rotor and rear bearing assembly, reduces the parts required for bearing lubrication, and makes the lubrication structure simple and compact. The front end and rear end of the bearing cavity are respectively sealed by a double-stage floating ring graphite sealing structure and a single-stage floating ring graphite sealing structure. The lubricating oil leakage rate is low, the sealing structure has high reliability, long service life, strong practicality, and is suitable for wide promotion and application.

[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of the bearing common cavity lubrication and sealing in the prior art;

[0020] Figure 2 It is a structural schematic diagram of a bearing common cavity lubrication and sealing structure of a preferred embodiment of the present invention;

[0021] Figure 3 yes Figure 2 The schematic diagram of the structure of the double-stage floating ring graphite seal structure in the bearing common cavity lubrication and sealing structure shown;

[0022] Figure 4 yes Figure 2 The schematic diagram of the structure of the single-stage floating ring graphite seal structure in the bearing common cavity lubrication and sealing structure shown;

[0023] Figure 5 It is a structural schematic diagram of the lubrication assembly in the bearing common cavity lubrication and sealing structure of the preferred embodiment of the present invention.

[0024] Legend:

[0025] 100, rotating shaft; 200, high-speed rotor; 300, front bearing seat assembly; 310, double-stage floating ring graphite seal structure; 311, front sealing runway; 312, first front graphite ring; 313, second front graphite ring; 314, installation bushing; 315, front outer retaining ring; 316, front inner retaining ring; 317, first front corrugated spring; 318, first front gasket; 319, second front corrugated spring; 301, second front gasket; 320, front bearing; 330, front locking member; 340, front elastic support; 350, front bearing seat; 360, front fastener; 40 0. Low-speed rotor; 500. Rear bearing seat assembly; 510. Single-stage floating ring graphite seal structure; 511. Rear sealing runway; 512. Rear graphite ring; 513. Rear retaining ring; 514. Rear corrugated spring; 515. Rear gasket; 520. Rear bearing; 530. Bearing spacer sleeve; 540. Middle bearing; 550. Middle locking piece; 560. Rear elastic support; 570. Rear bearing seat; 600. Bearing cavity; 700. Lubrication assembly; 710. Lubricating oil nozzle; 720. Middle fastener; 730. Oil inlet; 740. Oil return port; 800. Rear locking piece. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0027] Figure 1 A schematic diagram of the structure of the bearing common cavity lubrication and sealing in the prior art; Figure 2 It is a structural schematic diagram of a bearing common cavity lubrication and sealing structure of a preferred embodiment of the present invention; Figure 3 yes Figure 2 The schematic diagram of the structure of the double-stage floating ring graphite seal structure in the bearing common cavity lubrication and sealing structure shown; Figure 4 yes Figure 2 The schematic diagram of the structure of the single-stage floating ring graphite seal structure in the bearing common cavity lubrication and sealing structure shown; Figure 5 It is a structural schematic diagram of the lubrication assembly in the bearing common cavity lubrication and sealing structure of the preferred embodiment of the present invention.

[0028] like Figure 2As shown, the bearing common cavity lubrication and sealing structure of this embodiment includes a rotating shaft 100, a high-speed rotor 200 for transmitting a high speed and having a clearance fit with the rotating shaft 100, a front bearing seat assembly 300 for fixing in a casing and rotatably supporting the high-speed rotor 200, a low-speed rotor 400 for transmitting a low speed and fixedly connected to the rotating shaft 100, and a rear bearing seat assembly 500 for fixing in a casing and rotatably supporting the low-speed rotor 400. The rotating shaft 100, the high-speed rotor 200, the front bearing seat assembly 300, the rear bearing seat assembly 500 and the low-speed rotor 400 are enclosed to form a plurality of shafts for mounting. The bearing cavity 600 of the bearing is provided with a lubrication assembly 700 for injecting lubricating oil to lubricate multiple bearings. The end of the front bearing seat assembly 300 away from the rear bearing seat assembly 500 includes a double-stage floating ring graphite sealing structure 310 sleeved on the outside of the high-speed rotor 200 for introducing high-temperature and high-pressure gas and low-temperature and low-pressure gas to seal the front end of the bearing cavity 600. The end of the rear bearing seat assembly 500 away from the front bearing seat assembly 300 includes a single-stage floating ring graphite sealing structure 510 sleeved on the outside of the low-speed rotor 400 for introducing low-temperature and low-pressure gas to seal the rear end of the bearing cavity 600.Specifically, in the bearing common cavity lubrication and sealing structure of the present invention, the high-speed rotor 200 is clearance-matched with the rotating shaft 100 and is used to transmit high speed, the front bearing seat assembly 300 is fixed in the casing and rotatably supports the high-speed rotor 200, the low-speed rotor 400 is fixedly connected to the rotating shaft 100 and is used to transmit low speed, the rear bearing seat assembly 500 is fixed in the casing and rotatably supports the high-speed rotor 200, and the rotating shaft 100, the high-speed rotor 200, the front bearing seat assembly 300, the rear bearing seat assembly 500 and The low-speed rotor 400 encloses a bearing cavity 600 for installing multiple bearings, and then the multiple bearings are lubricated by a lubrication assembly 700 arranged in the bearing cavity 600. Multiple bearings only need one lubrication assembly 700 to achieve lubrication, which greatly reduces the number of parts required for lubrication. The structure is compact, the space occupied is small, and the reliability is high. The front end of the bearing cavity 600 is sealed by a double-stage floating ring graphite sealing structure 310 to prevent the lubricating oil from leaking out of the bearing cavity 600 through the front end of the bearing cavity 600. The double-stage floating ring graphite sealing structure 310 The structure 310 can simultaneously introduce high-temperature and high-pressure gas and low-temperature and low-pressure gas for sealing. The high-temperature and high-pressure gas is neutralized by introducing low-temperature and low-pressure gas to prevent excessive high temperature and high pressure from entering the bearing cavity 600 and affecting the cavity pressure. The rear end of the bearing cavity 600 is sealed by the single-stage floating ring graphite sealing structure 510 to prevent the lubricating oil from leaking into the bearing cavity 600 through the rear end of the bearing cavity 600. The floating ring graphite sealing structure adapts to the rotor eccentricity through radial floating to prevent the sealing gap from permanently increasing, thereby extending the service life and reducing the lubricating oil leakage rate. In this solution, the rotating shaft 100, the high-speed rotor 200, the front bearing 320 assembly, the low-speed rotor 400 and the rear bearing 520 assembly cooperate with each other to achieve lubrication of multiple bearings in the same cavity, reduce the parts required for bearing lubrication, and make the lubrication structure simple and compact. The front end and the rear end of the bearing cavity 600 are respectively sealed by the double-stage floating ring graphite sealing structure 310 and the single-stage floating ring graphite sealing structure 510, with a low lubricating oil leakage rate, high reliability of the sealing structure, long service life, strong practicality, and suitable for wide promotion and application. Optionally, the bearing common cavity lubrication and sealing structure also includes a rear locking piece 800, and the low-speed rotor 400 is axially pressed against the rotating shaft 100, and then the low-speed rotor 400 is axially pressed and fixed by the rear locking piece 800 to fasten the low-speed rotation speed to the rotating shaft 100.

[0029] like Figure 2As shown, in this embodiment, the front bearing seat assembly 300 includes a front bearing 320 that is sleeved on the outside of the high-speed rotor 200 and axially abuts against the double-stage floating ring graphite sealing structure 310, a front locking member 330 that is sleeved on the high-speed rotor 200 and axially abuts against the front bearing 320 and is used to axially tighten and fix the inner ring of the front bearing 320, a front elastic support 340 that is sleeved on the outside of the front bearing 320 and axially abuts against the front bearing 320 and is used to support the front bearing 320, a front bearing seat 350 that is connected to the front elastic support 340 and axially abuts against the front bearing 320 and is used to axially limit the front bearing 320 in the front elastic support 340, and a front sealing shell that is integrally formed with the front bearing seat 350 and is used to be fixed in the casing. Specifically, the high-speed rotor 200 is rotatably supported by the front bearing 320, the inner ring of the front bearing 320 is axially pressed against the high-speed rotor 200, and then the inner ring of the front bearing 320 is axially pressed and fixed by the front locking member 330 to achieve axial limitation of the inner ring of the front bearing 320, and the front elastic support 340 is used to support the front bearing 320 to buffer and absorb the vibration of the rear bearing 520 and the middle bearing 540 during operation, prevent vibration transmission, and improve reliability, and the outer ring of the front bearing 320 is axially pressed against the front elastic support 340, and then the front bearing seat 350 is axially pressed against the outer ring of the front bearing 320 to achieve axial limitation of the outer ring of the front bearing 320, and at the same time, since the front sealing shell and the front bearing seat 350 are integrally formed, the volume of the bearing cavity 600 is expanded, and the accumulated oil in the bearing cavity 600 is prevented from leaking into the bearing cavity 600 through the interference fit surface between the front sealing shell and the front bearing seat 350, and at the same time, the number of parts is reduced, which is convenient for assembly.

[0030] like Figure 3As shown, in this embodiment, the double-stage floating ring graphite sealing structure 310 includes a front sealing track 311 sleeved outside the high-speed rotor 200 and axially abutting against the high-speed rotor 200, a first front graphite ring 312 sleeved outside the front sealing track 311 and axially abutting against the front bearing seat 350 for radial floating to achieve floating sealing, a second front graphite ring 313 sleeved outside the front sealing track 311 for radial floating to achieve floating sealing, and a second front graphite ring 314 sleeved outside the first front graphite ring 312 and axially abutting against the second front bearing seat 350. The graphite ring 313 includes a mounting sleeve 314 for axially limiting the second front graphite ring 313 in the front bearing seat 350, a front outer retaining ring 315 which is radially plug-fitted with the front bearing seat 350 and axially abuts against the mounting sleeve 314 for axially limiting the mounting sleeve 314 in the front bearing seat 350, and a front retaining member which is radially plug-fitted with the mounting sleeve 314 and axially abuts against the first front graphite ring 312 for axially limiting the first front graphite ring 312 in the front bearing seat 350. Specifically, the front sealing track 311 is sleeved on the outside of the high-speed rotor 200, and the first front graphite ring 312 and the second front graphite ring 313 are sleeved on the outside of the front sealing track 311 to float radially with the rotation of the front sealing track 311 to achieve floating sealing and prevent rotor-static collision wear. The second front graphite ring 313 is axially limited in the front bearing seat 350 by installing the bushing 314, and the installing bushing 314 is axially limited in the front bearing seat 350 by the front outer retaining ring 315. The first front graphite ring 312 is axially limited in the front bearing seat 350 by the front clamping member. They are compactly assembled with high reliability. High-temperature and high-pressure gas is introduced through the sealing gap between the first front graphite ring 312 and the front sealing track 311 for sealing. Low-temperature and low-pressure gas is introduced through the sealing gap between the second front graphite ring 313 and the front sealing track 311 for sealing. The high-temperature and high-pressure gas is neutralized by the low-temperature and low-pressure gas to prevent excessive high-temperature and high-pressure gas from entering the bearing cavity 600 and affecting the strong pressure. Optionally, the front bearing seat 350 is provided with an air inlet for connecting the sealing gap between the second front graphite ring 313 and the front sealing track 311 to introduce low-temperature and low-pressure gas. Optionally, the sealing gap between the first front graphite ring 312 and the front sealing track 311 is larger than the sealing gap between the second front graphite ring 313 and the front sealing track 311 to meet the requirements of high-speed, high-temperature and high-pressure working conditions. Optionally, the outer diameter of the second front graphite ring 313 is larger than the inner diameter of the mounting bushing 314 to prevent the second front graphite ring 313 from being installed in the mounting bushing 314 by mistake.

[0031] like Figure 3As shown, in this embodiment, the front retainer includes a front inner retainer ring 316 plugged with the mounting bushing 314, a first front corrugated spring 317 fixedly connected to the front inner retainer ring 316, and a first front gasket 318 fixedly connected to the first front corrugated spring 317 and axially abutting against the first front graphite ring 312. Specifically, the front inner retainer ring 316 is plugged with the mounting bushing 314, and the first front corrugated spring 317 and the first front gasket 318 are axially abutted against the first front graphite ring 312, so that the first front graphite ring 312 is axially limited in the mounting bushing 314, and the first front corrugated spring 317 reduces the noise and vibration of the first front graphite ring 312 when it moves.

[0032] like Figure 3 As shown, in this embodiment, the installation bushing 314 includes a bushing body sleeved outside the first front graphite ring 312, a second front corrugated spring 319 fixedly connected to the bushing body, and a second front gasket 301 fixedly connected to the second front corrugated spring 319 and axially abutting against the second front graphite ring 313. Specifically, the second front corrugated spring 319 and the second front gasket 301 axially abut against the second front graphite ring 313 to axially limit the second front graphite ring 313 in the front bearing seat 350, and the second front corrugated spring 319 reduces the noise and vibration of the second front graphite ring 313 during movement.

[0033] like Figure 2 As shown, in this embodiment, the front bearing seat 350 is provided with a front limiting boss which is formed by radially extending inward and axially abutting against the front bearing 320 and is used to axially limit the outer ring of the front bearing 320. Specifically, the outer ring of the front bearing 320 is axially limited by the front limiting boss, so that the front bearing 320 is axially limited in the front elastic support 340.

[0034] like Figure 2 As shown, in this embodiment, the front bearing seat assembly 300 further includes a front fastener 360 that penetrates the front elastic support 340 to connect with the front bearing seat 350 and is used to fix the front elastic support 340 in the front bearing seat 350. Specifically, the front elastic support 340 is fixed in the front bearing seat 350 by the front fastener 360. Optionally, the front fixing member is a bolt or a screw.

[0035] like Figure 2As shown, in this embodiment, the rear bearing seat assembly 500 includes a rear bearing 520 sleeved on the outside of the low-speed rotor 400 and axially abutting against the single-stage floating ring graphite sealing structure 510, a bearing spacer sleeve 530 sleeved on the outside of the low-speed rotor 400 and axially abutting against the rear bearing 520, a middle bearing 540 sleeved on the outside of the low-speed rotor 400 and axially abutting against the bearing spacer sleeve 530, a middle locking member 550 sleeved on the low-speed rotor 400 and axially abutting against the middle bearing 540 for axially tightening and fixing the inner ring of the middle bearing 540, The rear elastic support 560, the rear bearing seat 570 connected to the rear elastic support 560 and axially abutting against the rear bearing 520 for axially limiting the rear bearing 520 within the rear elastic support 560, and the rear sealing shell integrally formed with the rear bearing seat 570 for fixing within the casing, the rear elastic support 560 is simultaneously sleeved outside the middle bearing 540 and the rear bearing 520, and axially abuts against the middle bearing 540 and the rear bearing 520 respectively for radially supporting and axially limiting the middle bearing 540 and the rear bearing 520 at the same time. Specifically, the inner ring of the rear bearing 520 axially abuts against the single-stage floating ring graphite sealing structure 510, the bearing spacer sleeve 530 axially abuts against the inner ring of the rear bearing 520, the inner ring of the middle bearing 540 axially abuts against the bearing spacer sleeve 530, and the middle locking member 550 axially abuts against the inner ring of the middle bearing 540 to tightly fix the inner ring of the middle bearing 540, so as to limit the axial direction of the inner ring of the rear bearing 520, the bearing spacer sleeve 530 and the inner ring of the middle bearing 540 on the low-speed rotor 400, and support the middle bearing 540 and the rear bearing 520 by the rear elastic support 560, so as to support the rear bearing 520 and the middle bearing 540. The vibration of the bearing 520 and the middle bearing 540 during operation is buffered and absorbed to prevent vibration transmission and improve reliability. The rear elastic support 560 is axially pressed against the outer ring of the middle bearing 540 and the outer ring of the rear bearing 520 respectively, and the rear bearing seat 570 is axially pressed against the outer ring of the rear bearing 520 to achieve axial limitation of the outer ring of the rear bearing 520. At the same time, since the rear sealing housing and the rear bearing seat 570 are integrally formed, the volume of the bearing cavity 600 is expanded to prevent the accumulated oil in the bearing cavity 600 from leaking into the bearing cavity 600 through the interference fit surface of the rear sealing housing and the rear bearing seat 570, and the number of parts is reduced to facilitate assembly. Optionally, the rear bearing seat 570 is provided with a rear limiting boss that extends radially inward and is axially pressed against the rear bearing 520 for axially limiting the outer ring of the rear bearing 520.

[0036] like Figure 4As shown, in this embodiment, the single-stage floating ring graphite sealing structure 510 includes a rear sealing track 511 sleeved outside the low-speed rotor 400 and axially against the low-speed rotor 400, a rear graphite ring 512 sleeved outside the rear sealing track 511 for radial floating to achieve floating sealing, and a rear clamping member plugged with the rear bearing seat 570 for axially limiting the rear graphite ring 512 in the rear bearing seat 570. Specifically, the rear sealing track 511 is sleeved outside the low-speed rotor 400, and the rear graphite ring 512 is sleeved outside the rear sealing track 511, so that the sealing track 511 rotates and then floats radially, so as to achieve floating sealing, prevent rotor-static collision wear, and the rear graphite ring 512 is axially limited in the rear bearing seat 570 by the rear clamping member, and they are assembled compactly with high reliability.

[0037] like Figure 4 As shown, in this embodiment, the rear clamping member includes a rear clamping ring 513 plugged with the rear bearing seat 570, a rear corrugated spring 514 fixedly connected to the rear clamping ring 513, and a rear gasket 515 fixedly connected to the rear corrugated spring 514 and axially abutting against the rear graphite ring 512. Specifically, the rear corrugated spring 514 and the rear gasket 515 axially abut against the rear graphite ring 512 to axially limit the rear graphite ring 512 in the rear bearing seat 570, and the rear corrugated spring 514 reduces the noise and vibration of the rear graphite ring 512 when it moves.

[0038] like Figure 2 and Figure 5As shown, in this embodiment, the lubrication assembly 700 includes a lubricating oil nozzle 710 arranged in the bearing cavity 600 and axially abutting against the middle bearing 540, a middle fastener 720 penetrating the lubricating oil nozzle 710 and fixedly connected to the rear bearing seat 570 for fixing the lubricating oil nozzle 710 in the bearing cavity 600, an oil inlet 730 opened in the rear bearing seat 570 and connected to the lubricating oil nozzle 710, an oil inlet passage connected to the oil inlet 730 for connecting to an oil pump, and a one-way valve arranged on the oil inlet passage for closing the oil inlet passage at a preset speed. Specifically, the lubricating oil nozzle 710 is fixed in the bearing cavity 600 through the middle fastener 720, and the lubricating oil in the oil pump is passed into the lubricating oil nozzle 710 through the oil inlet passage and the oil inlet port 730, and then the lubricating oil is respectively delivered to the front bearing seat assembly 300 and the rear bearing seat assembly 500 through the lubricating oil nozzle 710 to lubricate the bearing. When the rotor speed is lower than the preset speed, the sealing gas can no longer play a sealing effect. By closing the one-way valve to close the oil inlet passage, the lubricating oil of the oil pump is prevented from entering the bearing cavity 600, and the oil accumulation in the bearing cavity 600 is prevented from leaking out of the bearing cavity 600 through the sealing gap, thereby greatly reducing the lubricating oil consumption. Optionally, the middle fastener 720 is a screw or a bolt. Optionally, a return oil port 740 is provided in the front bearing seat 350 for connecting the return oil passage to guide the lubricating oil back to the oil pump. Optionally, the lubrication assembly 700 further includes an oil return pump connected to the oil return oil circuit, an oil tank connected to the oil return pump, and an oil supply pump connected to the lubricating oil tank and the oil inlet circuit respectively. When the rotor speed is lower than a preset speed, the one-way valve is closed to prevent the lubricating oil pumped by the oil supply pump from entering the bearing cavity 600, while the oil return pump continues to pump oil to reduce the oil accumulation in the bearing cavity 600 and prevent the lubricating oil from leaking out of the bearing cavity 600 through the gap in the graphite sealing structure. Optionally, the middle fastener 720 and the front fastener 360 are staggered in the circumferential direction to prevent mutual interference during assembly.

[0039] The aircraft engine of this embodiment includes the bearing common cavity lubrication and sealing structure in any of the above embodiments. Specifically, by adopting the above bearing common cavity lubrication and sealing structure to lubricate and seal the bearing 540 in the aircraft engine, the internal structure is simplified, the assembly difficulty is reduced, the lubricating oil leakage rate is reduced, the service life is extended, the reliability is improved, the practicability is strong, and it is suitable for wide promotion and application.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bearing common cavity lubrication and sealing structure, characterized in that: The invention comprises a rotating shaft (100), a high-speed rotor (200) which is clearance-matched with the rotating shaft (100) and is used to transmit a high rotation speed, a front bearing seat assembly (300) which is fixed in a casing and is used to rotationally support the high-speed rotor (200), a low-speed rotor (400) which is fixedly connected to the rotating shaft (100) and is used to transmit a low rotation speed, and a rear bearing seat assembly (500) which is used to be fixed in the casing and is used to rotationally support the low-speed rotor (400), wherein the rotating shaft (100), the high-speed rotor (200), the front bearing seat assembly (300), the rear bearing seat assembly (500) and the low-speed rotor (400) enclose a bearing cavity (600) for mounting a plurality of bearings. ), a lubrication assembly (700) for spraying lubricating oil to lubricate multiple bearings is arranged in the bearing cavity (600), the end of the front bearing seat assembly (300) away from the rear bearing seat assembly (500) includes a double-stage floating ring graphite sealing structure (310) sleeved outside the high-speed rotor (200) for introducing high-temperature high-pressure gas and low-temperature low-pressure gas to seal the front end of the bearing cavity (600), and the end of the rear bearing seat assembly (500) away from the front bearing seat assembly (300) includes a single-stage floating ring graphite sealing structure (510) sleeved outside the low-speed rotor (400) for introducing low-temperature low-pressure gas to seal the rear end of the bearing cavity (600); The front bearing seat assembly (300) comprises a front bearing (320) sleeved outside the high-speed rotor (200) and axially abutting against the double-stage floating ring graphite sealing structure (310), a front locking member (330) sleeved on the high-speed rotor (200) and axially abutting against the front bearing (320) and used to axially abut against the inner ring of the front bearing (320), a front elastic support (340) sleeved outside the front bearing (320) and axially abutting against the front bearing (320) and used to support the front bearing (320), a front bearing seat (350) connected to the front elastic support and axially abutting against the front bearing (320) and used to axially limit the front bearing (320) within the front elastic support (340), and a front sealing housing integrally formed with the front bearing seat (350) and used to be fixed in the casing; The double-stage floating ring graphite sealing structure (310) comprises a front sealing track (311) sleeved outside the high-speed rotor (200) and axially abutting against the high-speed rotor (200), a first front graphite ring (312) sleeved outside the front sealing track (311) and axially abutting against the front bearing seat (350) for radial floating to achieve floating sealing, a second front graphite ring (313) sleeved outside the front sealing track (311) and axially abutting against the second front graphite ring (313), and a second front graphite ring (314) sleeved outside the first front graphite ring (312) and axially abutting against the second front graphite ring (314). ) for axially limiting the second front graphite ring (313) in the front bearing seat (350), a front outer retaining ring (315) which is radially plug-fitted with the front bearing seat (350) and axially abutted against the mounting bushing (314) for axially limiting the mounting bushing (314) in the front bearing seat (350), and a front retaining member which is radially plug-fitted with the mounting bushing (314) and axially abutted against the first front graphite ring (312) for axially limiting the first front graphite ring (312) in the front bearing seat (350).

2. The bearing common cavity lubrication and sealing structure according to claim 1 is characterized in that: The front retaining member comprises a front inner retaining ring (316) pluggably matched with the mounting bushing (314), a first front corrugated spring (317) fixedly connected to the front inner retaining ring (316), and a first front gasket (318) fixedly connected to the first front corrugated spring (317) and abutting against the first front graphite ring (312) in the axial direction; and / or The mounting bushing (314) comprises a bushing body sleeved outside the first front graphite ring (312), a second front corrugated spring (319) fixedly connected to the bushing body, and a second front gasket (301) fixedly connected to the second front corrugated spring (319) and abutting against the second front graphite ring (313) in the axial direction.

3. The bearing common cavity lubrication and sealing structure according to claim 1 is characterized in that: The front bearing seat (350) is provided with a front limiting boss which extends radially inward and abuts against the front bearing (320) in the axial direction and is used for axially limiting the outer ring of the front bearing (320); and / or The front bearing seat assembly (300) further comprises a front fastener (360) which is penetrated through the front elastic support (340) to be connected to the front bearing seat (350) and is used to fix the front elastic support (340) inside the front bearing seat (350).

4. The bearing common cavity lubrication and sealing structure according to any one of claims 1 to 3, characterized in that: The rear bearing seat assembly (500) comprises a rear bearing (520) sleeved outside the low-speed rotor (400) and axially abutting against the single-stage floating ring graphite seal structure (510), a bearing spacer sleeve (530) sleeved outside the low-speed rotor (400) and axially abutting against the rear bearing (520), a middle bearing (540) sleeved outside the low-speed rotor (400) and axially abutting against the bearing spacer sleeve (530), a middle locking member (550) sleeved on the low-speed rotor (400) and axially abutting against the middle bearing (540) and used for axially pressing and fixing the inner ring of the middle bearing (540), and a rear spring member (560). A rear elastic support (560), a rear bearing seat (570) connected to the rear elastic support and axially abutting against the rear bearing (520) for axially limiting the rear bearing (520) within the rear elastic support (560), and a rear sealing housing integrally formed with the rear bearing seat (570) and fixed within the casing, wherein the rear elastic support (560) is simultaneously sleeved outside the middle bearing (540) and the rear bearing (520), and axially abuts against the middle bearing (540) and the rear bearing (520) respectively, so as to simultaneously provide radial support and axial limitation for the middle bearing (540) and the rear bearing (520).

5. The bearing common cavity lubrication and sealing structure according to claim 4 is characterized in that: The single-stage floating ring graphite sealing structure (510) comprises a rear sealing track (511) sleeved outside the low-speed rotor (400) and axially abutting against the low-speed rotor (400), a rear graphite ring (512) sleeved outside the rear sealing track (511) and used for radial floating to realize floating sealing, and a rear clamping member plugged into the rear bearing seat (570) and used for axially limiting the rear graphite ring (512) in the rear bearing seat (570).

6. The bearing common cavity lubrication and sealing structure according to claim 5 is characterized in that: The rear retaining member comprises a rear retaining ring (513) plugged into and matched with the rear bearing seat (570), a rear corrugated spring (514) fixedly connected to the rear retaining ring (513), and a rear gasket (515) fixedly connected to the rear corrugated spring (514) and abutting against the rear graphite ring (512) along the axial direction.

7. The bearing common cavity lubrication and sealing structure according to claim 4 is characterized in that: The lubrication assembly (700) comprises an oil nozzle (710) arranged in the bearing cavity (600) and axially abutting against the middle bearing (540), a middle fastener (720) penetrating the oil nozzle (710) and fixedly connected to the rear bearing seat (570) for fixing the oil nozzle (710) in the bearing cavity (600), an oil inlet (730) opened in the rear bearing seat (570) and connected to the oil nozzle (710), an oil inlet passage connected to the oil inlet (730) for connecting to an oil pump, and a one-way valve arranged on the oil inlet passage for closing the oil inlet passage at a preset speed.

8. An aircraft engine, characterized in that: The invention comprises the bearing common cavity lubrication and sealing structure as described in any one of claims 1 to 7.

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