Oil cavity bleed air anti-icing system and turbofan engine

Abstract

The present invention discloses a lubricating oil chamber bleed air anti-icing system and a turbofan engine, comprising a power shaft, a first lubricating oil chamber for lubricating a rotor-stator bearing at the front end of the power shaft, a second lubricating oil chamber for lubricating a rotor-stator bearing at the rear end of the power shaft, an axial chamber opened in the power shaft, and an intake cone chamber surrounded by an intake cone and a fan wheel. The first lubricating oil chamber and the second lubricating oil chamber are respectively connected to the axial chamber, an oil-gas separator is arranged on the connecting end of the axial chamber and the intake cone chamber, and the end of the axial chamber facing away from the intake cone chamber is closed. The gas in the first lubricating oil chamber and the second lubricating oil chamber flows through the axial chamber, the oil-gas separator and the intake cone chamber in turn and is discharged from the first exhaust hole on the intake cone. The lubricating oil filtered by the oil-gas separator flows into the first lubricating oil chamber through the axial chamber. The combination of the lubricating oil chamber ventilation system and the intake cone anti-icing system can simplify the pipeline design and reduce the number of parts, thereby reducing the design and processing difficulty of corresponding structural parts on the turbofan engine.

Description

Technical Field

[0001] The present invention relates to the field of aviation engine technology, and in particular to a lubricating oil cavity bleed air anti-icing system. In addition, the present invention also relates to a turbofan engine comprising the lubricating oil cavity bleed air anti-icing system. Background Art

[0002] In turbofan engines, there are two types of ventilation designs for the oil cavity: Figure 1 As shown, the interconnected ventilation design of the lubricating oil chambers is as follows: the first lubricating oil chamber 1 is located between the fan disk 100 and the diverter casing, responsible for lubricating and cooling the first ball bearing 71, the third bearing 73, and the second bearing 72; the second lubricating oil chamber 2 is located at the bearing of the turbine disk 300, responsible for lubricating and cooling the fourth rod bearing 74 and the fifth rod bearing 75. The first lubricating oil chamber 1 is connected to the ventilation pipe 39 via a first centrifugal ventilation structure 91, and the second lubricating oil chamber 2 is connected to the ventilation pipe 39 via a second centrifugal ventilation structure 92. The first and second lubricating oil chambers 1 and 2 are connected through the power shaft 3 and the ventilation pipe 39. The left ends of the power shaft 3 and the ventilation pipe 39 are sealed with a plug 37, which discharges the gas in the first and second lubricating oil chambers 1 and 2 to the right. The independent ventilation design of the lubricating oil chambers is as follows: centrifugal ventilation structures are designed on the casings of the first and second lubricating oil chambers 1 and 2 to provide independent ventilation for each lubricating oil chamber.

[0003] The anti-icing structure design of the intake cone of a turbofan engine is generally based on drawing air from the fan disk or turbine disk, and then directing the gas to the intake cone through the opening on the power shaft. Figure 2 This anti-icing structure uses air bleed from the rear of the rectifier. The first-stage fan disk 101 accelerates and pressurizes the incoming air. Some of the air enters the first plenum 105 through the gap between the rectifier 102 and the second-stage fan disk 103, and then enters the second plenum 107 through the vent 106 on the second-stage fan disk 103. The boundary of the second plenum 107 is bounded by the power shaft 3, the second-stage fan disk 103, and the support 104. The rotor and stator are sealed by a grate seal or graphite seal. The air in the second plenum 107 enters the power shaft through the circumferential opening 38 on the power shaft 34, and then flows to the atmosphere through the first exhaust hole 81 of the intake cone 8 at the left end, thus achieving the anti-icing effect of the intake cone. The air bleed from the rear of the turbine disk is similar to the air bleed from the fan disk. It enters the plenum through the gap between the turbine disk and the guide, then enters the axial chamber 31 of the power shaft 3 and flows forward to the intake cone 8.

[0004] At present, the oil cavity ventilation and intake cone anti-icing functions of turbofan engines are separated independently. For small and medium-sized turbofan engines, the two-way system will inevitably increase the complexity and number of parts of the turbofan engine, resulting in increased difficulty in the design and processing of engine parts; in addition, the oil cavity ventilation will cause partial oil loss through the centrifugal ventilation structure, resulting in increased oil consumption. Summary of the Invention

[0005] The present invention provides an oil cavity bleed air anti-icing system and a turbofan engine to solve the technical problems that the oil cavity ventilation and air inlet cone anti-icing functions of the existing turbofan engine are independently separated, which increases the difficulty of designing and processing the guide of small and medium-sized turbofan engines, and the oil cavity ventilation passes through the centrifugal ventilation structure, causing partial oil loss and increasing the consumption of lubricating oil.

[0006] According to one aspect of the present invention, a lubricating oil chamber air bleed anti-icing system is provided, comprising a power shaft, a first lubricating oil chamber for lubricating a rotor-stator bearing at the front end of the power shaft, a second lubricating oil chamber for lubricating a rotor-stator bearing at the rear end of the power shaft, an axial chamber opened in the power shaft, and an intake cone chamber surrounded by an intake cone and a fan wheel, the first lubricating oil chamber and the second lubricating oil chamber are respectively connected to the axial chamber, an oil-gas separator is arranged on the connecting end of the axial chamber and the intake cone chamber, the end of the axial chamber facing away from the intake cone chamber is closed, the gas in the first lubricating oil chamber and the second lubricating oil chamber flows through the axial chamber, the oil-gas separator and the intake cone chamber in turn and is discharged from the first exhaust hole on the intake cone, and the lubricating oil filtered by the oil-gas separator flows into the first lubricating oil chamber through the axial chamber.

[0007] In this embodiment, the oil-gas separator includes the shell arranged in the axial chamber, the end cover forming a filter chamber with the shell, a locking piece for connecting the shell and the end cover, and a metal sponge arranged in the filter chamber, an air inlet hole is provided on the end cover, an air outlet hole is provided on the end face of the shell, and an oil drain hole for discharging lubricating oil into the axial chamber is provided on the cylindrical surface of the shell.

[0008] In this embodiment, a limiting convex ring is provided on the inner wall surface of the power shaft, and a boss adapted to the limiting convex ring is provided on the outer cylindrical surface of the shell. The limiting convex ring and the boss cooperate to define the axial position of the oil-gas separator.

[0009] In this embodiment, a first circumferential hole for connecting the first lubricating oil chamber and the axial center chamber and a second circumferential hole for connecting the second lubricating oil chamber and the axial center chamber are provided on the power shaft. The inner circular wall surface of the power shaft includes a first guide surface and a second guide surface. The first guide surface expands from the oil-gas separator to the first circumferential hole, and the second guide surface expands from the second circumferential hole to the first circumferential hole.

[0010] In this embodiment, the second circumferential hole has an aperture d , the number of openings is n , given the required heated air temperature at the inlet cone T 0. Pressure P 0 and flowQ 0, the temperature of the gas in the second lubricating oil chamber T 1 and pressure P 1, then the aperture of the second circumferential hole d The calculation formula is as follows:

[0011]

[0012] in, C is the pressure drop coefficient through the metal sponge 54, C d is the orifice flow coefficient, R The gas constant of air is 287 J / (kg·K).

[0013] In this embodiment, an air inlet ring is also included. The air inlet ring and the oil-gas separator form an air inlet chamber for guiding the gas filtered by the oil-gas separator to the front end of the intake cone chamber. The air inlet ring is provided with an air inlet hole for connecting the air inlet chamber and the intake cone chamber.

[0014] In this embodiment, one end of the air induction ring is threadedly connected to the power shaft, and the other end is connected to the tip of the intake cone via a locking screw. The locking screw is provided with a second exhaust hole arranged along the axial direction of the power shaft.

[0015] In this embodiment, a sealing ring is arranged between the air induction ring and the power shaft and / or between the oil-gas separator and the power shaft.

[0016] In this embodiment, a limit block is provided on the end face of the shell, and a slot adapted to the limit block is provided on the air induction ring. The limit block cooperates with the slot to limit the circumferential rotation of the oil-gas separator.

[0017] According to another aspect of the present invention, a turbofan engine is provided, which includes the above-mentioned oil cavity bleed air anti-icing system.

[0018] The present invention has the following beneficial effects:

[0019] The lubricating oil cavity air bleed anti-icing system of the present invention is characterized in that the first lubricating oil cavity and the second lubricating oil cavity are internal spaces of the engine that carry the oil supply and oil return mechanisms. Due to the evaporation of lubricating oil in the process of cooling the bearings, the lubricating oil cavity is filled with an oil-gas mixture. In addition, the rotor and stator need to be sealed for air bleed, and part of the sealed gas inevitably enters the first lubricating oil cavity and the second lubricating oil cavity, thereby increasing the cavity pressure of the first lubricating oil cavity and the second lubricating oil cavity. The mixed gas of the first lubricating oil cavity and the second lubricating oil cavity can be ventilated through the axial cavity of the power shaft, so that the first lubricating oil cavity and the second lubricating oil cavity are ventilated. The cavity pressure of the second lubricating oil cavity is balanced, and the mixed gas in the axial cavity can be filtered through the oil-gas separator to recover the lubricating oil particles contained therein, and flow back to the first lubricating oil cavity through the axial cavity, which can reduce the lubricating oil consumption. At the same time, the filtered gas is introduced into the intake cone cavity to heat the intake cone to achieve the purpose of anti-icing the intake cone; the combination of the lubricating oil cavity ventilation system and the intake cone anti-icing system can simplify the pipeline design and reduce the number of parts, thereby reducing the design and processing difficulty of the corresponding structural parts on the turbofan engine, and is especially suitable for small and medium-sized turbofan engines.

[0020] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a structural diagram of the existing lubricating oil cavity communication ventilation system;

[0023] Figure 2 It is a structural diagram of an existing intake cone anti-icing system;

[0024] Figure 3 2 is a schematic structural diagram of an oil cavity bleed air anti-icing system according to a preferred embodiment of the present invention;

[0025] Figure 4 2. It is a structural schematic diagram of an air entrainment ring according to a preferred embodiment of the present invention;

[0026] Figure 5 is a schematic structural diagram of a power shaft according to a preferred embodiment of the present invention;

[0027] Figure 6 It is a structural schematic diagram of an oil-gas separator according to a preferred embodiment of the present invention.

[0028] Legend:

[0029] 100, fan wheel; 101, first-stage fan wheel; 102, rectifier; 103, second-stage fan wheel; 104, support seat; 105, first air collecting cavity; 106, vent hole; 107, second air collecting cavity; 200, high-pressure compressor rotor wheel; 300, turbine disk; 1, first lubricating oil cavity; 2, second lubricating oil cavity; 3, power shaft; 31, axis chamber; 32, first circumferential hole; 33, second circumferential hole; 34, limiting convex ring; 35, first guide surface; 36, second guide surface; 37, plug cover; 38, circumferential opening; 39, ventilation pipe; 4, intake cone chamber; 5, oil Gas separator; 51. Shell; 52. End cover; 53. Locking piece; 54. Metal sponge; 55. Air inlet; 56. Air outlet; 57. Oil drain hole; 58. Boss; 59. Limit block; 6. Air bleed ring; 61. Air bleed hole; 62. Locking screw; 63. Second exhaust hole; 64. Slot; 65. Sealing ring; 66. Air bleed chamber; 67. Locking nut; 71. First bearing; 72. Second bearing; 73. Third bearing; 74. Fourth bearing; 75. Fifth bearing; 8. Air intake cone; 81. First exhaust hole; 91. First centrifugal ventilation structure; 92. Second centrifugal ventilation structure. DETAILED DESCRIPTION

[0030] 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.

[0031] Please also refer to Figures 4 to 6 The lubricating oil cavity bleed air anti-icing system of this embodiment includes a power shaft 3, a first lubricating oil cavity 1 for lubricating the rotor-stator bearings (first bearing 71, second bearing 72, and third bearing 73) at the front end of the power shaft 3, a second lubricating oil cavity 2 for lubricating the rotor-stator bearings (fourth bearing 74 and fifth bearing 75) at the rear end of the power shaft 3, an axial chamber 31 opened in the power shaft 3, and an intake cone chamber 4 surrounded by an intake cone 8 and a fan impeller 100 (the intake cone 8 is connected to the fan impeller 100, and the fan impeller 100 is locked by a locking nut). 67 is connected to the power shaft 3), the first lubricating oil chamber 1 and the second lubricating oil chamber 2 are respectively communicated with the axial chamber 31, and an oil-gas separator 5 is arranged on the communicating end between the axial chamber 31 and the intake cone chamber 4. The end of the axial chamber 31 away from the intake cone chamber 4 is closed by a plug cover 37. The gas in the first lubricating oil chamber 1 and the second lubricating oil chamber 2 flows through the axial chamber 31, the oil-gas separator 5 and the intake cone chamber 4 in turn and is discharged from the first exhaust hole 81 on the intake cone 8. The lubricating oil filtered by the oil-gas separator 5 flows into the first lubricating oil chamber 1 through the axial chamber 31.

[0032] In the lubricating oil cavity bleed air anti-icing system of this embodiment, the first lubricating oil cavity 1 and the second lubricating oil cavity 2 are the internal spaces of the engine that carry the oil supply and oil return mechanisms. Due to the evaporation of lubricating oil in the process of cooling the bearings, the lubricating oil cavity is filled with oil-gas mixture. In addition, the rotor and stator need to be sealed and bleed air, and part of the sealed gas inevitably enters the first lubricating oil cavity 1 and the second lubricating oil cavity 2, increasing the cavity pressure of the first lubricating oil cavity 1 and the second lubricating oil cavity 2. The mixed gas in the first lubricating oil cavity 1 and the second lubricating oil cavity 2 can be ventilated through the axial chamber 31 of the power shaft 3, so that the first lubricating oil cavity 1 The pressure in the second lubricating oil chamber 2 is balanced, and the mixed gas in the axial chamber 31 can be filtered and the lubricating oil particles therein can be recovered through the oil-gas separator 5, and flow back to the first lubricating oil chamber 1 through the axial chamber 31, which can reduce the lubricating oil consumption; at the same time, the filtered gas is introduced into the intake cone chamber 4 to heat the intake cone 8, so as to achieve the purpose of anti-icing the intake cone 8; the combination of the lubricating oil chamber ventilation system and the intake cone anti-icing system can simplify the pipeline design and reduce the number of parts, thereby reducing the design and processing difficulty of the corresponding structural parts on the turbofan engine, and is particularly suitable for small and medium-sized turbofan engines.

[0033] like Figure 4 、 Figure 5 and Figure 6 As shown, in this embodiment, the oil-gas separator 5 includes a shell 51 arranged in the axis chamber 31, an end cover 52 that forms a filter chamber with the shell 51, a locking member 53 for connecting the shell 51 and the end cover 52, and a metal sponge 54 arranged in the filter chamber, an air inlet 55 is provided on the end cover 52, an air outlet 56 is provided on the end surface of the shell 51, and an oil drain hole 57 for draining the lubricating oil into the axis chamber 31 is provided on the cylindrical surface of the shell 51; the mixed gas in the axis chamber 31 enters the oil-gas separator 5 from the air inlet 55 on the end cover 52, and the mixed gas passes through the metal sponge 54. When the oil-gas separator 54 is in contact with the metal sponge 54, the lubricating oil adheres to the metal sponge 54. As the power shaft 3 drives the oil-gas separator 5 to rotate, the centrifugal force causes the lubricating oil attached to the metal sponge 54 to be flung toward the inner cylindrical wall of the housing 51 and then, through the oil drain hole 57 in the housing 51, into the axial chamber 31 of the power shaft 3. The gas separated from the lubricating oil enters the intake cone chamber 4 through the outlet hole 56 on the end surface of the housing 51, thereby achieving the anti-icing function of the intake cone 8. The oil-gas separator 5 can filter and recover lubricating oil particles entrained in the mixed gas, preventing them from being discharged into the atmosphere through the first exhaust hole 81 in the intake cone 8. Optionally, the outlet hole 56 is arranged coaxially with the power shaft 3, and the intake hole 55 is arranged in the high-radius area of ​​the end cover 52. This ensures that when the mixed gas flows through the metal sponge 54 from the intake hole 55, the airflow direction is from the high-radius area to the low-radius area, and the lubricating oil attached to the metal sponge 54 flows from the low-radius area to the high-radius area, thereby improving the oil-gas separation. Optionally, the locking member 53 is a screw, a bolt or a rivet.

[0034] like Figure 5 and Figure 6As shown, in this embodiment, a limiting convex ring 34 is arranged on the inner wall surface of the power shaft 3, and a boss 58 adapted to the limiting convex ring 34 is arranged on the outer cylindrical surface of the shell 51. The limiting convex ring 34 and the boss 58 cooperate to limit the axial position of the oil-gas separator 5; it can prevent the oil-gas separator 5 from axial movement in the axial chamber 31, reduce the vibration of the power shaft 3, and ensure the stability of the power shaft 3.

[0035] like Figure 3 and Figure 6 As shown, in this embodiment, the power shaft 3 is provided with a first circumferential hole 32 for connecting the first lubricating oil chamber 1 with the axial chamber 31, and a second circumferential hole 33 for connecting the second lubricating oil chamber 2 with the axial chamber 31. The inner circumferential wall of the power shaft 3 includes a first guide surface 35 and a second guide surface 36. The first guide surface 35 expands from the oil-gas separator 5 toward the first circumferential hole 32, and the second guide surface 36 expands from the second circumferential hole 33 toward the first circumferential hole 32. This ensures that the maximum inner diameter of the axial chamber 31 is at the opening of the first circumferential hole 32. The lubricating oil filtered and separated by the oil-gas separator 5 can flow smoothly toward the first circumferential hole 32 under the action of centrifugal force and return to the lubricating oil chamber 011 through the first circumferential hole 32. Optionally, the first circumferential holes 32 are staggered along the circumference of the power shaft 3, ensuring the oil return and ventilation capabilities of the first circumferential hole 32 without weakening the strength of the power shaft 3. Optionally, the second circumferential holes 33 are staggered along the circumference of the power shaft 3 to enhance the ventilation capacity of the second circumferential holes 33. Optionally, both the first guide surface 35 and the second guide surface 36 are conical surfaces to guide the lubricating oil toward the first circumferential hole 32. Optionally, the first guide surface 35 and the second guide surface 36 each form a stepped inner hole to guide the lubricating oil toward the first circumferential hole 32. Optionally, both the first guide surface 35 and the second guide surface 36 are guide grooves formed on the inner wall of the power shaft 3 and facing the first circumferential hole 32 to guide the lubricating oil toward the first circumferential hole 32. Optionally, in some cases where it is inconvenient to provide the second circumferential hole 33 on the power shaft 3 at the bearing of the turbine disk 300, the second circumferential hole 33 can be provided in the middle section of the power shaft 3.

[0036] The design of the holes for ventilation on the power shaft 3 must first consider whether the number and location of the holes meet the requirements of the power shaft 3 under high and low cycle fatigue stress. The location and number of the holes are planned by presetting the total opening area to ensure that the mixed gas can heat the intake cone 8 after passing through the metal sponge 54 for filtration, ensuring that the anti-icing effect of the intake cone 8 can meet the use requirements. In this embodiment, the aperture of the second circumferential hole 33 connecting the second lubricating oil cavity 2 and the shaft chamber 31 is d , the number of openings of the second circumferential hole 33 is n , given the required heated air temperature at the inlet cone 8 T 0. Pressure P 0 and flow Q 0, the temperature of the gas in the second lubricating oil chamber 2T 1 and pressure P 1, then the aperture of the second circumferential hole 33 is d The calculation formula is as follows:

[0037]

[0038] in, C is the pressure drop coefficient through the metal sponge, C d is the orifice flow coefficient (related to the orifice shape and Reynolds number, usually determined by experiment), R The gas constant of air is 287 J / (kg·K).

[0039] like Figure 3 As shown, in this embodiment, the oil cavity air bleed anti-icing system also includes an air bleed ring 6, which and the end face of the shell 51 of the oil-gas separator 5 form an air bleed chamber 66 for guiding the gas filtered by the oil-gas separator 5 to the front end of the intake cone chamber 4, and an air bleed hole 61 is provided on the air bleed ring 6 for connecting the air bleed chamber 66 and the intake cone chamber 4; the mixed gas passes through the oil-gas separator 5 forward and enters the air bleed chamber 66, and then enters the intake cone chamber 4 through the air bleed hole 61 on the air bleed ring 6, which can ensure the anti-icing effect of the front end of the intake cone 8.

[0040] like Figure 4 and Figure 5 As shown, in this embodiment, one end of the air inlet ring 6 is threadedly connected to the power shaft 3, and the other end is connected to the tip of the intake cone 8 via a locking screw 62. The locking screw 62 is provided with a second exhaust hole 63 arranged along the axis of the power shaft 3. On the one hand, the locking screw 62 passes through the tip of the intake cone 8 and is threadedly connected to the air inlet ring 6, ensuring the connection strength of the intake cone 8 and reducing vibration of the intake cone 8. On the other hand, the second exhaust hole 63 in the locking screw 62 can discharge filtered air from the tip of the intake cone 8, thereby enhancing the anti-icing effect of the tip of the intake cone 8. Optionally, a clamping groove is provided along the circumference of the locking screw 62 to facilitate tightening and removal by the operator.

[0041] like Figure 6 As shown, in this embodiment, a sealing ring 65 is disposed between the air inlet ring 6 and the power shaft 3 to prevent leakage of the mixed oil and gas through the gap between the air inlet ring 6 and the power shaft 3, ensuring that lubricating oil particles in the mixed gas are fully recovered. Optionally, a sealing ring 65 is disposed between the oil-gas separator 5 and the power shaft 3 to prevent leakage of the mixed oil and gas through the gap between the oil-gas separator 5 and the power shaft 3, ensuring that lubricating oil particles in the mixed gas are fully recovered.

[0042] like Figure 5 and Figure 6As shown, in this embodiment, at least one limit block 59 is arranged on the end face of the shell 51, and a groove 64 adapted to the limit block 59 is arranged on the air ring 6. When the air ring 6 is tightened to the power shaft 3, the limit block 59 and the groove 64 cooperate to limit the circumferential rotation of the oil-gas separator 5; it can avoid the relative rotation of the power shaft 3 and the oil-gas separator 5, ensure that the oil-gas separator 5 can throw the lubricating oil attached to the metal sponge 54 out of the oil drain hole 57, and at the same time avoid the wear caused by the relative rotation of the oil-gas separator 5 and the power shaft 3, thereby ensuring the service life of the power shaft 3 and the dynamic oil-gas separator 5.

[0043] A turbofan engine includes the above-mentioned oil chamber air bleed anti-icing system; the first oil chamber 1 and the second oil chamber 2 are the internal spaces of the engine that carry the oil supply and oil return mechanisms, and the mixed gas in the first oil chamber 1 and the second oil chamber 2 can be ventilated through the axial chamber 31 of the power shaft 3, so that the cavity pressure of the first oil chamber 1 and the second oil chamber 2 is balanced; the two ends of the air bleed ring 6 are respectively connected to the power shaft 3 and the air intake cover 8, and the air bleed ring 6 cooperates with the power shaft 3 to clamp the oil-gas separator 5, thereby limiting the axial position of the oil-gas separator 5 and limiting the rotation of the oil-gas separator 5 relative to the power shaft 3, which can reduce the vibration of the air intake cover 8 and the power shaft 3; the mixed gas in the axial chamber 31 The gas can be filtered through the oil-gas separator 5 to recover the lubricating oil particles contained therein, and the recovered lubricating oil is thrown into the axial chamber 31 through the oil drain hole 57 on the shell 51. The lubricating oil in the axial chamber 31 is collected to the first circumferential hole 32 through the first guide surface 35 and the second guide surface 36, and then flows back to the first lubricating oil chamber 1 through the first circumferential hole 32, which can reduce the lubricating oil consumption. At the same time, the filtered gas is introduced into the intake cone chamber 4 to heat the intake cone 8, so as to achieve the purpose of anti-icing the intake cone 8; the combination of the lubricating oil chamber ventilation system and the intake cone anti-icing system can simplify the pipeline design and reduce the number of parts, thereby reducing the design and processing difficulty of the corresponding structural parts on the turbofan engine.

[0044] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A lubricating oil cavity bleed air anti-icing system, characterized in that: The invention comprises a power shaft (3), a first lubricating oil chamber (1) for lubricating a bearing between a front rotor and a stator of the power shaft (3), a second lubricating oil chamber (2) for lubricating a bearing between a rear rotor and a stator of the power shaft (3), an axial chamber (31) opened in the power shaft (3), and an intake cone chamber (4) surrounded by an intake cone and a fan wheel, wherein the first lubricating oil chamber (1) and the second lubricating oil chamber (2) are respectively communicated with the axial chamber (31), and the axial chamber (31) is connected to the intake cone. An oil-gas separator (5) is arranged on the connecting end of the chamber (4), and the end of the axial chamber (31) away from the intake cone chamber (4) is closed. The gas in the first lubricating oil chamber (1) and the second lubricating oil chamber (2) flows through the axial chamber (31), the oil-gas separator (5) and the intake cone chamber (4) in sequence and is discharged from the first exhaust hole (81) on the intake cone. The lubricating oil filtered by the oil-gas separator (5) flows into the first lubricating oil chamber (1) through the axial chamber (31).

2. The oil cavity bleed air anti-icing system according to claim 1, characterized in that: The oil-gas separator (5) includes a shell (51) arranged in the axial chamber (31), an end cover (52) that forms a filter chamber with the shell (51), a locking member (53) for connecting the shell (51) and the end cover (52), and a metal sponge (54) arranged in the filter chamber, an air inlet (55) is provided on the end cover (52), an air outlet (56) is provided on the end surface of the shell (51), and an oil discharge hole (57) for discharging lubricating oil into the axial chamber (31) is provided on the cylindrical surface of the shell (51).

3. The oil cavity bleed air anti-icing system according to claim 2, characterized in that: A limiting convex ring (34) is provided on the inner wall surface of the power shaft (3), and a convex shoulder (58) adapted to the limiting convex ring (34) is provided on the outer cylindrical surface of the housing (51). The limiting convex ring (34) cooperates with the convex shoulder (58) to limit the axial position of the oil-gas separator (5).

4. The oil cavity bleed air anti-icing system according to claim 2 or 3, characterized in that: The power shaft (3) is provided with a first circumferential hole (32) for connecting the first lubricating oil cavity (1) and the axial chamber (31), and a second circumferential hole (33) for connecting the second lubricating oil cavity (2) and the axial chamber (31). The inner circular wall of the power shaft (3) includes a first guide surface (35) and a second guide surface (36). The first guide surface (35) expands from the oil-gas separator (5) to the first circumferential hole (32), and the second guide surface (36) expands from the second circumferential hole (33) to the first circumferential hole (32), so that the maximum inner diameter of the axial chamber (31) is at the opening position of the first circumferential hole (32).

5. The oil cavity bleed air anti-icing system according to claim 4, characterized in that: The second circumferential hole (33) has a diameter d , the number of openings is n , given the required heated air temperature at the inlet cone T 0. Pressure P 0 and flow Q 0, the temperature of the gas in the second lubricating oil cavity (2) T 1 and pressure P 1, then the aperture of the second circumferential hole (33) is d The calculation formula is as follows: ； in, C is the pressure drop coefficient through the metal sponge (54), C d is the orifice flow coefficient, R The gas constant of air is 287 J / (kg·K).

6. The oil cavity bleed air anti-icing system according to claim 4, characterized in that: The air inlet ring (6) is further provided. The air inlet ring (6) and the oil-gas separator (5) form an air inlet chamber (66) for guiding the gas filtered by the oil-gas separator (5) to the front end of the intake cone chamber (4). The air inlet ring (6) is provided with an air inlet hole (61) for connecting the air inlet chamber (66) and the intake cone chamber (4).

7. The oil cavity bleed air anti-icing system according to claim 6, characterized in that: One end of the air induction ring (6) is screwed to the power shaft (3), and the other end is connected to the tip of the air inlet cone via a locking screw (62). The locking screw (62) is provided with a second exhaust hole (63) arranged along the axial direction of the power shaft (3).

8. The oil cavity bleed air anti-icing system according to claim 6, characterized in that: A sealing ring (65) is arranged between the air induction ring (6) and the power shaft (3) and / or between the oil-gas separator (5) and the power shaft (3).

9. The oil cavity bleed air anti-icing system according to claim 6, characterized in that: A limit block (59) is provided on the end surface of the housing (51), and a slot (64) adapted to the limit block (59) is provided on the air induction ring (6). The limit block (59) cooperates with the slot (64) to limit the circumferential rotation of the oil-gas separator (5).

10. A turbofan engine, characterized in that: The oil cavity bleed air anti-icing system comprises the one described in any one of claims 1 to 9.

Images