Double-shaft transmission mechanism and aero-engine

Abstract

The application discloses a double-shaft transmission mechanism, which comprises a hollow transmission shaft arranged for connecting a turbine and a speed reducer respectively to transmit torque, a first bearing seat arranged on an axial first end of the transmission shaft to support the transmission shaft, a second bearing seat arranged on an axial second end of the transmission shaft to support the bearing seat, a ventilation shaft arranged in the transmission shaft and having an inner cavity communicated with inner cavities of the first bearing seat and the second bearing seat to balance pressure in the inner cavities of the first bearing seat and the second bearing seat, an inter-shaft supporting structure arranged on an inner wall of the transmission shaft and supporting the ventilation shaft, and an inter-shaft supporting ring arranged between the first bearing seat and the second bearing seat and fixedly sleeved on the ventilation shaft to prevent the ventilation shaft and the transmission shaft from colliding and rubbing. In addition, the application further discloses an aero-engine comprising the double-shaft transmission mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aero-engine transmission mechanism, in particular to a double-shaft transmission mechanism. Furthermore, the present application also relates to an aero-engine comprising the double-shaft transmission mechanism. BACKGROUND

[0002] In an aero-engine, a main shaft transmission mechanism penetrates through the entire aero-engine and connects a turbine and a speed reducer respectively, and mainly functions to transmit the torque generated by the turbine to the speed reducer. In the design of an aero-engine, the larger the hub diameter of the turbine disk is, the lower the overall structural strength of the turbine disk is, and the lower the service life of the turbine disk is. In order to improve the service life of the turbine disk, the hub diameter of the turbine disk is usually relatively small. The main shaft of the main shaft transmission mechanism needs to penetrate through the hub of the turbine disk, and the diameter of the main shaft of the main shaft transmission mechanism is also relatively small, and is usually designed as a flexible slender shaft with a large length-diameter ratio.

[0003] The main shaft is supported in the bearing seat by bearings. Since the rotation speed of the main shaft in the aero-engine is high, the pressure in the bearing seat is very high during the high-speed rotation of the main shaft. Therefore, a ventilation structure needs to be designed to reduce the pressure in the bearing seat. However, the existing ventilation structure is usually designed in the bearing seat, which leads to a complex internal structure of the bearing seat, a large design difficulty, and low reliability. SUMMARY

[0004] The present application provides a double-shaft transmission mechanism and an aero-engine to solve the technical problem of the complex structure of the bearing seat supporting the transmission shaft, the large design difficulty, and the low reliability in the existing aero-engine.

[0005] According to one aspect of the present application, a double-shaft transmission mechanism is provided, which comprises a hollow transmission shaft arranged for connecting a turbine and a speed reducer respectively to transmit torque, a first bearing seat arranged on the axial first end of the transmission shaft for supporting the transmission shaft, a second bearing seat arranged on the axial second end of the transmission shaft for supporting the bearing seat, a ventilation shaft arranged in the transmission shaft and having an inner cavity in communication with the inner cavities of the first bearing seat and the second bearing seat for balancing the pressure in the inner cavities of the first bearing seat and the second bearing seat, an inter-shaft supporting structure arranged on the inner wall of the transmission shaft and supporting the ventilation shaft, and an inter-shaft supporting ring arranged between the first bearing seat and the second bearing seat and fixedly arranged on the outer surface of the ventilation shaft for preventing the ventilation shaft and the transmission shaft from colliding and rubbing.

[0006] As a further improvement of the above technical solution:

[0007] Further, the outer wall surface of the inter-shaft supporting ring is arranged in an arc shape along the axial direction.

[0008] Furthermore, the inter-shaft support structure includes a first inter-shaft support sleeve sleeved on the first axial end of the ventilation shaft and connected to the inner wall of the torque transmission shaft, and a second inter-shaft support sleeve sleeved on the second axial end of the ventilation shaft and connected to the inner wall of the torque transmission shaft.

[0009] Furthermore, the first inter-shaft support sleeve and the first bearing housing are arranged accordingly, and a first ventilation hole is provided on the first axial end of the ventilation shaft, which penetrates the first inter-shaft support sleeve and the torsion transmission shaft in a radial direction to connect the inner cavity of the first bearing housing. The second inter-shaft support sleeve and the second bearing housing are arranged accordingly, and a second ventilation hole is provided on the second axial end of the ventilation shaft, which penetrates the second inter-shaft support sleeve and the torsion transmission shaft in a radial direction to connect the inner cavity of the second bearing housing.

[0010] Furthermore, the first bearing housing includes a first support bearing supporting a first end of the torsion transmission shaft, and the first support bearing and the first inter-shaft support sleeve are correspondingly arranged; and / or the second bearing housing includes a second support bearing supporting a second axial end of the torsion transmission shaft, and the second support bearing and the second inter-shaft support sleeve are correspondingly arranged.

[0011] Furthermore, the ventilation shaft and the torque transmission shaft operate in the same direction and at the same speed.

[0012] Furthermore, the ratio of the radial wall thickness of the torsion shaft to the radial wall thickness of the ventilation shaft is 2-4.

[0013] Furthermore, the inter-shaft support ring and the torsion transmission shaft are fitted with a clearance.

[0014] Furthermore, multiple inter-shaft support rings are provided, and the multiple inter-shaft support rings are arranged at intervals along the axial direction of the ventilation shaft.

[0015] According to another aspect of the invention, an aircraft engine is also provided, which includes the aforementioned dual-shaft drive mechanism.

[0016] The present invention has the following beneficial effects:

[0017] The dual-shaft transmission mechanism of the present invention has a torsion transmission shaft whose first axial end is reliably mounted in the aircraft engine via a first bearing housing, and a second axial end of the torsion transmission shaft is reliably mounted in the aircraft engine via a second bearing housing. The torsion transmission shaft is connected to a turbine and a reducer respectively, so as to transmit the torque generated by the turbine to the reducer, so as to transmit the working power to the aircraft through the reducer. A ventilation shaft is arranged inside the torsion transmission shaft through an inter-shaft support structure, and the ventilation shaft is connected to the inner cavities of the first bearing housing and the second bearing housing respectively, so as to balance the pressure in the inner cavities of the first bearing housing and the second bearing housing. At the same time, the rotation of the ventilation shaft generates negative pressure, thereby reducing the pressure in the first bearing housing and the second bearing housing. Since both the ventilation shaft and the torsion transmission shaft are flexible, slender shafts with a large length-to-diameter ratio, they experience significant vibration amplitudes under operating conditions. Therefore, an inter-shaft support ring is fitted onto the ventilation shaft to prevent wear caused by vibration and collision between the ventilation shaft and the torsion transmission shaft during operation. This solution transmits torque through the torsion transmission shaft and reduces pressure through ventilation via the ventilation shaft. Compared to existing technologies, this solution achieves both ventilation and pressure reduction while simplifying the structure of the first and second bearing seats supporting the torsion transmission shaft, making it easier to design and ensuring high reliability. Furthermore, the inter-shaft support ring controls the vibration amplitude of the ventilation shaft, preventing collision and wear between the torsion transmission shaft and the ventilation shaft, thus significantly extending their service life. This solution is highly practical and suitable for widespread promotion and application.

[0018] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the dual-shaft transmission mechanism according to a preferred embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the inter-shaft support ring in a preferred embodiment of the dual-shaft transmission mechanism of the present invention.

[0022] Legend:

[0023] 100 Torque transmission shaft; 200 First bearing housing; 210 First support bearing; 300 Second bearing housing; 310 Second support bearing; 400 Ventilation shaft; 500 Inter-shaft support ring; 600 First inter-shaft support sleeve; 700 Second inter-shaft support sleeve. Detailed Implementation

[0024] The embodiments of the present invention will be 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.

[0025] Figure 1 This is a schematic diagram of the structure of the dual-shaft transmission mechanism according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the inter-shaft support ring in a preferred embodiment of the dual-shaft transmission mechanism of the present invention.

[0026] like Figure 1 and Figure 2As shown, the dual-shaft transmission mechanism of this embodiment includes a hollow torque transmission shaft 100 for connecting the turbine and the reducer to transmit torque, a first bearing seat 200 sleeved on the first axial end of the torque transmission shaft 100 for supporting the torque transmission shaft 100, a second bearing seat 300 sleeved on the second axial end of the torque transmission shaft 100 for supporting the bearing seat, a ventilation shaft 400 arranged inside the torque transmission shaft 100 and whose inner cavity communicates with the inner cavities of the first bearing seat 200 and the second bearing seat 300 respectively for balancing the pressure in the inner cavities of the first bearing seat 200 and the second bearing seat 300, an inter-shaft support structure arranged on the inner wall of the torque transmission shaft 100 and supporting the ventilation shaft 400, and an inter-shaft support ring 500 arranged between the first bearing seat 200 and the second bearing seat 300 and fixedly sleeved on the outside of the ventilation shaft 400 for preventing the ventilation shaft 400 and the torque transmission shaft 100 from rubbing against each other. Specifically, in the dual-shaft transmission mechanism of the present invention, the first axial end of the torsion transmission shaft 100 is reliably mounted in the aero-engine via a first bearing housing 200, and the second axial end of the torsion transmission shaft 100 is reliably mounted in the aero-engine via a second bearing housing 300. The torsion transmission shaft 100 is connected to a turbine and a reducer respectively, so as to transmit the torque generated by the turbine to the reducer, so as to transmit the working power to the aircraft through the reducer. A ventilation shaft 400 is arranged inside the torsion transmission shaft 100 through an inter-shaft support structure, and the ventilation shaft 400 connects the inner cavities of the first bearing housing 200 and the second bearing housing 300 respectively, so as to balance the pressure in the inner cavities of the first bearing housing 200 and the second bearing housing 300. At the same time, the rotation of the ventilation shaft 400 generates negative pressure, thereby reducing the pressure in the first bearing housing 200 and the second bearing housing 300. Since both the ventilation shaft 400 and the torsion transmission shaft 100 are flexible, slender shafts with a large length-to-diameter ratio, they experience significant vibration amplitude under operating conditions. Therefore, an inter-shaft support ring 500 is fitted onto the ventilation shaft 400 to prevent wear caused by vibration and collision between the ventilation shaft 400 and the torsion transmission shaft 100 during operation. This solution transmits torque through the torsion transmission shaft 100 and provides ventilation and pressure reduction through the ventilation shaft 400. Compared to existing technologies, this solution achieves ventilation and pressure reduction while simplifying the structure of the first bearing housing 200 and the second bearing housing 300 supporting the torsion transmission shaft 100. This simplifies design, enhances reliability, and further optimizes the design. The inter-shaft support ring 500 limits the vibration amplitude of the ventilation shaft 400, preventing collision and wear between the torsion transmission shaft 100 and the ventilation shaft 400, significantly extending their service life. This design is highly practical and suitable for widespread promotion and application. It should be understood that the torsion transmission shaft 100 is a hollow shaft to facilitate the installation of the ventilation shaft 400, and the ventilation shaft 400 is also a hollow shaft to facilitate ventilation and pressure reduction. It should be understood that the inter-shaft support ring 500 can be fixedly installed on the outside of the ventilation shaft 400 by means of interference fit, small clearance + welding, or adhesive bonding.

[0027] like Figure 2As shown, in this embodiment, the outer wall surface of the inter-shaft support ring 500 is arranged in an arc shape along the axial direction. Specifically, because the outer wall surface of the inter-shaft support ring 500 is arranged in an arc shape along the axial direction, when the torsion transmission shaft 100 vibrates, it and the inter-shaft support ring 500 are in line-fit contact, which greatly reduces the contact area and thus reduces the wear of the inter-shaft support ring 500 on the torsion transmission shaft 100.

[0028] like Figure 1 As shown, in this embodiment, the inter-shaft support structure includes a first inter-shaft support sleeve 600 sleeved on the first axial end of the ventilation shaft 400 and connected to the inner wall of the torque transmission shaft 100, and a second inter-shaft support sleeve 700 sleeved on the second axial end of the ventilation shaft 400 and connected to the inner wall of the torque transmission shaft 100. Specifically, the first axial end of the ventilation shaft 400 is reliably installed inside the torque transmission shaft 100 by the first inter-shaft support sleeve 600, and the second axial end of the ventilation shaft 400 is reliably installed inside the torque transmission shaft 100 by the second inter-shaft support sleeve 700. The first inter-shaft support sleeve 600 and the second inter-shaft support sleeve 700 work together to achieve reliable installation of the ventilation shaft 400.

[0029] like Figure 1 As shown, in this embodiment, the first inter-shaft support sleeve 600 and the first bearing seat 200 are arranged accordingly. A first ventilation hole is provided on the first axial end of the ventilation shaft 400, which penetrates the first inter-shaft support sleeve 600 and the torsion transmission shaft 100 in a radial direction to connect the inner cavity of the first bearing seat 200. The second inter-shaft support sleeve 700 and the second bearing seat 300 are arranged accordingly. A second ventilation hole is provided on the second axial end of the ventilation shaft 400, which penetrates the second inter-shaft support sleeve 700 and the torsion transmission shaft 100 in a radial direction to connect the inner cavity of the second bearing seat 300. Specifically, the ventilation shaft 400 and the inner cavity of the first bearing housing 200 are connected through the first ventilation hole, and the ventilation shaft 400 and the inner cavity of the second bearing housing 300 are connected through the second ventilation hole, so that the inner cavities of the first bearing housing 200 and the second bearing housing 300 are interconnected to achieve pressure balance. The first inter-shaft support sleeve 600 and the first bearing housing 200 are arranged correspondingly, and the second inter-shaft support sleeve 700 and the second bearing housing 300 are arranged correspondingly to achieve precise control of the air duct and facilitate ventilation and pressure reduction.

[0030] like Figure 1As shown, in this embodiment, the first bearing housing 200 includes a first support bearing 210 supporting the first end of the torsion transmission shaft 100, and the first support bearing 210 and the first inter-axial support sleeve 600 are correspondingly arranged; and / or the second bearing housing 300 includes a second support bearing 310 supporting the axial second end of the torsion transmission shaft 100, and the second support bearing 310 and the second inter-axial support sleeve 700 are correspondingly arranged. Specifically, the first end of the torsion transmission shaft 100 is rotatably supported in the first bearing housing 200 by the first support bearing 210, and the second end of the torsion transmission shaft 100 is reliably supported in the second bearing housing 300 by the second support bearing 310. The first support bearing 210 and the second support bearing 310 work together to achieve reliable support for the torsion transmission shaft 100. The corresponding arrangement of the first support bearing 210 and the first inter-axial support sleeve 600, and the corresponding arrangement of the second support bearing 310 and the second inter-axial support sleeve 700, enables precise control of the air duct and facilitates ventilation and pressure reduction.

[0031] In this embodiment, the ventilation shaft 400 and the torque transmission shaft 100 operate in the same direction and at the same speed. Specifically, by ensuring that the ventilation shaft 400 and the torque transmission shaft 100 operate in the same direction and at the same speed, relative movement between the shaft support ring 500 and the torque transmission shaft 100 is avoided, minimizing wear on the torque transmission shaft 100 caused by the shaft support ring 500. It should be understood that since the function of the ventilation shaft 400 is ventilation and the function of the torque transmission shaft 100 is torque transmission, even if the operating direction and speed are the same, the difference in diameter and radial wall thickness of the two shafts will still result in different vibration amplitudes and mode shapes, thus posing a risk of wear between the two shafts.

[0032] like Figure 1 As shown, in this embodiment, the ratio of the radial wall thickness of the torque transmission shaft 100 to the radial wall thickness of the ventilation shaft 400 is 2-4. Specifically, by ensuring that the ratio of the radial wall thickness of the torque transmission shaft 100 to the radial wall thickness of the ventilation shaft 400 is 2-4, the reliability of the torque transmission shaft 100 and the ventilation shaft 400 during operation is ensured. When the ratio of the radial wall thickness of the torque transmission shaft 100 to the radial wall thickness of the ventilation shaft 400 is less than 2, the strength of the torque transmission shaft 100 is too low, and it cannot transmit torque, or the ventilation flow of the ventilation shaft 400 is too small. When the ratio of the radial wall thickness of the torque shaft to the radial wall thickness of the ventilation shaft 400 is greater than 4, the ventilation flow of the ventilation shaft 400 is too small, and the pressure reduction capacity is poor.

[0033] like Figure 1 As shown, in this embodiment, the inter-shaft support ring 500 and the torsion transmission shaft 100 are fitted with a clearance fit. Specifically, the clearance fit ensures convenient assembly while limiting the amplitude of the ventilation shaft 400 under operating conditions.

[0034] In this embodiment, multiple inter-shaft support rings 500 are provided, and the multiple inter-shaft support rings 500 are arranged at intervals along the axial direction of the ventilation shaft 400. It should be understood that the inter-shaft support rings 500 are installed at the position where the radial clearance is minimal due to the different vibration modes between the ventilation shaft 400 and the torsion transmission shaft 100 under working conditions. By calculating the working speeds of the ventilation shaft 400 and the torsion transmission shaft 100, the vibration modes of the ventilation shaft 400 and the torsion transmission shaft 100 at different critical speeds are obtained, and then the corresponding number of inter-shaft support rings 500 are installed accordingly. When the first critical speed is exceeded, one inter-shaft support ring 500 is installed, and when the second critical speed is exceeded, at least three inter-shaft support rings 500 are required to minimize the vibration amplitude of the ventilation shaft 400.

[0035] The aero-engine of this embodiment includes the aforementioned dual-shaft transmission mechanism. Specifically, by employing the aforementioned dual-shaft transmission mechanism to transmit torque and achieve ventilation and pressure reduction, the structure of the first bearing housing 200 and the second bearing housing 300 is greatly simplified, and the ventilator shaft 400 and the torque transmission shaft 100 are prevented from rubbing against each other. It is highly practical and suitable for widespread promotion and application.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual-shaft transmission mechanism, characterized in that, The device includes a hollow torque transmission shaft (100) for connecting a turbine and a reducer to transmit torque, a first bearing housing (200) for supporting the torque transmission shaft (100) on its first axial end, a second bearing housing (300) for supporting the bearing housing on its second axial end, and a bearing housing arranged inside the torque transmission shaft (100) with its inner cavity connected to the inner cavity of the first bearing housing (200) and the second bearing housing (300). The ventilation shaft (400) is connected to the cavity to balance the pressure in the inner cavity of the first bearing housing (200) and the inner cavity of the second bearing housing (300); the inter-shaft support structure is arranged on the inner wall of the torsion transmission shaft (100) and supports the ventilation shaft (400); and the inter-shaft support ring (500) is arranged between the first bearing housing (200) and the second bearing housing (300) and fixedly sleeved on the outside of the ventilation shaft (400) to prevent the ventilation shaft (400) and the torsion transmission shaft (100) from rubbing against each other. Both the ventilation shaft (400) and the torsion transmission shaft (100) are flexible, slender shafts; The outer wall surface of the inter-shaft support ring (500) is arranged in an arc shape along the axial direction; The ventilation shaft (400) and the torque transmission shaft (100) operate in the same direction and at the same speed. The ratio of the radial wall thickness of the torsion shaft (100) to the radial wall thickness of the ventilation shaft (400) is 2-4; The inter-shaft support ring (500) and the torsion transmission shaft (100) are clearance-fitted; Multiple inter-shaft support rings (500) are provided, and the multiple inter-shaft support rings (500) are arranged at intervals along the axial direction of the ventilation shaft 400. The inter-shaft support rings (500) are installed at the position where the radial clearance is the smallest due to the different vibration modes between the ventilation shaft (400) and the torsion transmission shaft (100) under working conditions. By calculating the working speed of the ventilation shaft (400) and the torsion transmission shaft (100), the vibration modes of the ventilation shaft (400) and the torsion transmission shaft (100) under different order critical speeds are obtained, and then the corresponding number of inter-shaft support rings (500) are installed accordingly.

2. The dual-shaft transmission mechanism according to claim 1, characterized in that, The inter-shaft support structure includes a first inter-shaft support sleeve (600) sleeved on the first axial end of the ventilation shaft (400) and connected to the inner wall of the torsion transmission shaft (100), and a second inter-shaft support sleeve (700) sleeved on the second axial end of the ventilation shaft (400) and connected to the inner wall of the torsion transmission shaft (100).

3. The dual-shaft transmission mechanism according to claim 2, characterized in that, The first inter-shaft support sleeve (600) and the first bearing housing (200) are arranged accordingly. A first ventilation hole is provided on the first axial end of the ventilation shaft (400) to penetrate the first inter-shaft support sleeve (600) and the torsion transmission shaft (100) in a radial direction to connect the inner cavity of the first bearing housing (200). The second inter-shaft support sleeve (700) and the second bearing housing (300) are arranged accordingly. A second ventilation hole is provided on the second axial end of the ventilation shaft (400) to penetrate the second inter-shaft support sleeve (700) and the torsion transmission shaft (100) in a radial direction to connect the inner cavity of the second bearing housing (300).

4. The dual-shaft transmission mechanism according to claim 3, characterized in that, The first bearing housing (200) includes a first support bearing (210) supporting the first end of the torsion transmission shaft (100), and the first support bearing (210) and the first inter-shaft support sleeve (600) are correspondingly arranged; and / or The second bearing housing (300) includes a second support bearing (310) supporting the second axial end of the torsion transmission shaft (100), and the second support bearing (310) and the second interaxial support sleeve (700) are arranged accordingly.

5. The dual-shaft transmission mechanism according to any one of claims 1-4, characterized in that, Multiple inter-shaft support rings (500) are provided, and the multiple inter-shaft support rings (500) are arranged at intervals along the axial direction of the ventilation shaft (400).

6. An aircraft engine, characterized in that, Includes the dual-shaft transmission mechanism as described in any one of claims 1-5.

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