Transmission structure of a gas turbine accessory gearbox

Abstract

The application provides a transmission structure of a gas turbine accessory gearbox, comprising a bearing seat, a central transmission shaft, a first bearing unit and a second bearing unit. The bearing seat is integrally formed by additive manufacturing. The central transmission shaft is obliquely arranged on the bearing seat and is suitable for transmitting power. The first bearing unit rotatably supports one end of the central transmission shaft, so that the central transmission shaft is fixedly connected with the bearing seat. The second bearing unit rotatably supports a horizontal transmission assembly in the gas turbine accessory gearbox. The second bearing unit is a roller bearing without an inner ring. The roller of the roller bearing directly contacts with a shaft neck of the horizontal transmission assembly.

Description

Technical Field

[0001] This application belongs to the field of gas turbines and relates to a transmission structure for a gas turbine accessory gearbox. Background Technology

[0002] The primary function of the accessory gear transmission structure in a gas turbine is to extract mechanical power from the main rotor of the gas turbine and, after speed change and reversal via the gear transmission system, drive key accessories such as the fuel pump, lubricating oil pump, hydraulic servo actuators, and generator. It is a crucial component ensuring the safe and stable operation of the gas turbine. With the development of gas turbines towards higher power density and compactness, the accessory gearbox needs to achieve efficient power transmission within a limited space while withstanding increasingly larger loads. Therefore, the arrangement of the transmission structure, the load-bearing capacity of the supporting bearings, and the overall structural reliability become critical design considerations.

[0003] In related technologies, the central drive section of the accessory gear transmission structure for gas turbines often employs a linearly arranged drive shaft coupled with ordinary angular contact ball bearings. However, this traditional approach has revealed several shortcomings in practical applications. First, the linear central drive shaft often requires multiple stages of transition gears to achieve proper engagement with other gears in the accessory gearbox, resulting in a large number of parts, a long transmission chain, and a certain impact on transmission efficiency. Second, in high-power-density gas turbines, the meshing of bevel gears on the central drive shaft generates significant axial forces. Ordinary single-row angular contact ball bearings have relatively limited axial load-bearing capacity, making it difficult to reliably withstand such alternating heavy loads over long periods, easily accelerating bearing wear and fatigue failure. Furthermore, during engine assembly and actual operation, misalignment between shafts is inevitable. Traditional rigid connections or ordinary bearing support structures have weak adaptability to lateral loads, causing the support bearings to bear significant additional lateral forces, further exacerbating bearing wear and overall engine vibration, and reducing the service life and operational reliability of the accessory gearbox.

[0004] In summary, existing gas turbine accessory gear transmission structures have significant shortcomings in terms of the number of parts, load-bearing capacity, and alignment adaptability, making it difficult to achieve both a compact structure and light weight while ensuring high load-bearing capacity and long-term operational reliability. Therefore, improving the central drive arrangement and bearing support method to enhance the overall performance of the accessory gearbox is of practical significance. Summary of the Invention

[0005] In view of this, to solve at least one technical problem in related technologies and other aspects, this application proposes a transmission structure for a gas turbine accessory gearbox, including a bearing housing, a central drive shaft, a first bearing unit, and a second bearing unit. The bearing housing is constructed as a single piece through additive manufacturing; the central drive shaft is constructed as an inclined arrangement on the bearing housing, suitable for transmitting power; the first bearing unit rotatably supports one end of the central drive shaft, so that the central drive shaft is fixedly connected to the bearing housing; the second bearing unit rotatably supports a horizontal transmission component within the gas turbine accessory gearbox, and the second bearing unit is a roller bearing without an inner ring, wherein the rollers of the roller bearing without an inner ring directly contact one journal of the horizontal transmission component.

[0006] According to an embodiment of this application, the first bearing unit is a double-row angular contact ball bearing. The double-row angular contact ball bearing is fitted onto the meshing end of the central drive shaft and the bearing housing. The outer ring of the double-row angular contact ball bearing is fixedly connected to the bearing housing through a flange.

[0007] According to an embodiment of this application, the aforementioned transmission structure further includes a first bevel gear, which is mounted on the central drive shaft via a spline connection. This gear is suitable for transmitting torque and allows relative displacement between the central drive shaft and the first bevel gear, thereby isolating misalignment and thermal deformation stress caused by operating conditions.

[0008] According to an embodiment of this application, the bearing housing is provided with a lubrication oil passage, which extends to a double-row angular contact ball bearing and a roller bearing without an inner ring.

[0009] According to an embodiment of this application, a flange is provided on the outer ring of the inner ring roller bearing for fixed connection with the gas turbine accessory gearbox.

[0010] According to an embodiment of this application, the aforementioned transmission structure further includes a second bevel gear, a third bevel gear, and a spur gear arranged axially between the second bevel gear and the third bevel gear.

[0011] According to an embodiment of this application, an inner ringless roller bearing is mounted on one side journal of a spur gear, and the inner ringless roller bearing is suitable for providing rotational support for the spur gear.

[0012] According to an embodiment of this application, the aforementioned transmission structure further includes an input bevel gear suitable for connection with the main shaft of a gas turbine, the input bevel gear being supported on a bearing housing by a flanged angular contact ball bearing.

[0013] According to an embodiment of this application, the aforementioned transmission structure further includes a spur gear set, which includes a first accessory spur gear, a second accessory spur gear, and a third accessory spur gear. The spur gear set is connected to a horizontal transmission shaft and is suitable for driving a fuel pump, an oil pump, and a motor, respectively.

[0014] According to an embodiment of this application, the aforementioned transmission structure further includes an idler gear configured to mesh with a spur gear set.

[0015] According to embodiments of this application, the bearing housing is integrally formed through additive manufacturing, enabling the creation of a complex structure with an inclined mounting surface. This ensures the positioning accuracy between the bearing housing and the central drive shaft while eliminating the need for connecting parts. The central drive shaft is inclined on the bearing housing, resulting in a shorter transmission path compared to a straight arrangement. This reduces the use of intermediate transition gears, making the structure more compact. The first bearing unit rotatably supports one end of the central drive shaft on the bearing housing, achieving reliable positioning and fixed connection of the shaft. The second bearing unit uses a ringless roller bearing, where the rollers directly contact the journal of the horizontal transmission component, eliminating the need for an inner ring and saving radial space. Simultaneously, the rollers roll directly on the high-hardness journal, increasing support rigidity and reducing the number of parts, facilitating assembly. Attached Figure Description

[0016] Figure 1 This is a perspective view of the transmission structure in the embodiments of this application from a first-view perspective;

[0017] Figure 2 This is a perspective view of the transmission structure in the embodiment of this application from a second perspective;

[0018] Figure 3 This is a perspective view of the bearing housing from a first-view perspective in an embodiment of this application;

[0019] Figure 4 This is a perspective view of the bearing housing from a second perspective in an embodiment of this application.

[0020] [Meaning of Labels in the Attached Image]

[0021] 1-Input bevel gear, 2-First bevel gear, 3-Second bevel gear, 4-Third bevel gear, 5-Spur gear, 6-First accessory spur gear, 7-Second accessory spur gear, 8-Idler gear, 9-Third accessory spur gear, 10-Central drive shaft, 11-Double row angular contact ball bearing, 12-Bearing housing, 13-Angular contact ball bearing, 14-Roller bearing without inner ring, 15-Compression nut, 16-Deep groove ball bearing; A-Double row angular contact ball bearing lubrication circuit. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0023] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this application.

[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0025] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0026] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by a person with ordinary skill in the art to which this application pertains. Where the terms "first," "second," etc., are used throughout, they are used only to distinguish similar objects and should not be construed as indicating or implying their relative importance, order of precedence, or implicitly specifying the number of technical features indicated. It should be understood that the data in the descriptions of "first," "second," etc., can be interchanged where appropriate.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] In the description of this application, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted where they may cause confusion in understanding this application. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect their actual size, scale, or actual positional relationships. Additionally, any reference symbols placed within parentheses in this application should not be construed as limiting the scope of this application.

[0030] Similarly, to simplify this application and aid in understanding one or more of the various disclosed aspects, in the above description of exemplary embodiments of this application, various features of this application are sometimes grouped together into a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0032] In the process of implementing this disclosure, it was discovered that the central drive shaft of traditional gas turbine accessory gearboxes is mostly arranged in a straight line, resulting in the transmission path from the engine main shaft to the accessory gearbox requiring multiple stages of transition gears, leading to a large number of parts and a large axial dimension. Simultaneously, while the straight shaft arrangement simplifies the structure of the bearing housing 12, it is difficult to adapt to compact space requirements. Furthermore, the support for the horizontal drive shaft within the gearbox typically uses needle roller bearings or ball bearings with inner rings. The inner ring occupies a certain radial space, and the interference fit between the inner ring and the journal increases the complexity of part machining and assembly. Based on these observations, this disclosure considers setting the central drive shaft to an inclined configuration, allowing it to more directly introduce power into the gearbox, thereby reducing intermediate transmission links. Simultaneously, using additive manufacturing technology to integrally form the bearing housing 12 allows for the realization of complex inclined support surfaces while ensuring structural strength. For the horizontal drive shaft, an attempt was made to eliminate the bearing inner ring, allowing the rollers to directly contact the journal, saving radial space and reducing the number of parts, thus forming the technical solution of this disclosure.

[0033] Figure 1 This is a perspective view of the transmission structure in the embodiment of this application from a first-view perspective.

[0034] This application proposes a transmission structure for a gas turbine accessory gearbox, such as... Figure 1 As shown, the assembly includes a bearing housing 12, a central drive shaft 10, a first bearing unit, and a second bearing unit. The bearing housing 12 is constructed as a single piece through additive manufacturing; the central drive shaft 10 is constructed to be inclinedly mounted on the bearing housing 12 for power transmission; the first bearing unit rotatably supports one end of the central drive shaft 10, thereby fixing the central drive shaft 10 to the bearing housing 12; the second bearing unit rotatably supports the horizontal transmission assembly within the gas turbine accessory gearbox, and the second bearing unit is a roller bearing 14 without an inner ring, wherein the rollers of the roller bearing 14 directly contact one journal of the horizontal transmission assembly.

[0035] According to an embodiment of this application, the bearing housing 12 is integrally formed by additive manufacturing, enabling the fabrication of a complex structure with an inclined mounting surface. This ensures the positioning accuracy between the bearing housing 12 and the central drive shaft 10, while eliminating the need for connecting parts. The central drive shaft 10 is inclinedly mounted on the bearing housing 12, resulting in a shorter transmission path compared to a straight arrangement. This reduces the use of intermediate transition gears, making the structure more compact. The first bearing unit rotatably supports one end of the central drive shaft 10 on the bearing housing 12, achieving reliable positioning and fixed connection of the shaft. The second bearing unit uses a ringless roller bearing 14, where the rollers directly contact the journal of the horizontal transmission component, eliminating the need for an inner ring. This eliminates the need for an additional inner ring on the journal, saving radial space. Simultaneously, the rollers roll directly on the high-hardness journal, improving support rigidity and reducing the number of parts, facilitating assembly.

[0036] Figure 3 This is a perspective view of the bearing housing from a first-view perspective in an embodiment of this application.

[0037] In some specific embodiments, such as Figure 3 As shown, the bearing housing 12 is integrally formed by additive manufacturing, which eliminates the need for connecting parts and seals required for traditional split bearing housings 12, thus reducing the number of parts.

[0038] In some specific embodiments, the central drive shaft 10 is arranged at an angle, making the transmission path more direct, reducing intermediate transition gears, and improving transmission efficiency.

[0039] In some specific embodiments, the inner ring-less roller bearing 14 directly supports the horizontal transmission assembly, eliminating the inner ring, further reducing the number of parts, and improving support stiffness, which is beneficial to improving system reliability.

[0040] In some specific embodiments, the tilt angle of the central drive shaft 10 can be any angle.

[0041] According to an embodiment of this application, the first bearing unit is a double-row angular contact ball bearing 11. The double-row angular contact ball bearing 11 is fitted onto the meshing end of the central drive shaft 10 and the bearing housing 12. The outer ring of the double-row angular contact ball bearing 11 is fixedly connected to the bearing housing 12 through a flange edge.

[0042] According to embodiments of this application, the double-row angular contact ball bearing 11 simultaneously bears axial and radial forces, with a stronger axial load-bearing capacity capable of handling the large axial load generated by bevel gear meshing. The outer ring is fixedly connected to the bearing housing 12 via a flange, eliminating the need for an additional bearing clamping structure, simplifying assembly, and ensuring higher connection reliability.

[0043] In some specific embodiments, the double-row angular contact ball bearing 11 is disposed at the meshing end of the bevel gear, which can cope with load changes during startup and operation.

[0044] According to an embodiment of this application, the aforementioned transmission structure further includes a first bevel gear 2, which is mounted on the central drive shaft 10 via a spline connection. It is suitable for transmitting torque and allows relative displacement between the central drive shaft 10 and the first bevel gear 2 to isolate misalignment and thermal deformation stress caused by operating conditions.

[0045] According to embodiments of this application, the spline connection allows for minute relative displacement between the central drive shaft 10 and the first bevel gear 2. When thermal deformation or misalignment occurs during engine operation, the spline clearance can absorb the resulting additional stress, preventing lateral loads from being transmitted to the bearings and gears, and reducing the risk of tooth surface wear and bearing failure.

[0046] Figure 4 This is a perspective view of the bearing housing from a second perspective in an embodiment of this application.

[0047] According to embodiments of this application, such as Figure 4 As shown, the bearing housing 12 has a lubrication oil passage inside, which extends to the double-row angular contact ball bearing 11 and the inner ringless roller bearing 14.

[0048] According to embodiments of this application, the lubrication oil passage integrated inside the bearing housing 12 can directly deliver lubricating oil to the working surfaces of the double-row angular contact ball bearing 11 and the inner ringless roller bearing 14. Wherein, Figure 4 A shown in the diagram is the lubrication circuit for a double-row angular contact ball bearing.

[0049] In some specific embodiments, the bearing housing 12 is integrally formed through additive manufacturing. The internal lubrication channels do not require separate machining or external piping, eliminating the need for additional parts such as oil pipe joints and gaskets required in traditional structures, thus reducing the overall number of parts. The lubrication channels are directly formed inside the bearing housing 12, extending via the shortest path to the double-row angular contact ball bearing 11 and the inner ringless roller bearing 14, avoiding the risk of leakage at pipe connections and improving the sealing reliability of the lubrication system. Simultaneously, the integrally formed structure reduces assembly steps, lowering manufacturing and assembly costs.

[0050] According to an embodiment of this application, a flange is provided on the outer ring of the inner ring roller bearing 14 for fixed connection with the gas turbine accessory gearbox.

[0051] According to an embodiment of this application, the outer ring of the inner ringless roller bearing 14 is fixedly connected to the gearbox via a flange, eliminating the need for an additional bearing base or pressure plate. This structure simplifies the installation process, reduces the number of connecting parts, and ensures reliable circumferential positioning of the bearing outer ring, preventing rotation of the outer ring under working load.

[0052] Figure 2 This is a perspective view of the transmission structure in the embodiment of this application from a second perspective.

[0053] According to embodiments of this application, such as Figure 2 As shown, the aforementioned transmission structure also includes a second bevel gear 3, a third bevel gear 4, and a spur gear 5 arranged axially between the second bevel gear 3 and the third bevel gear 4.

[0054] According to an embodiment of this application, the spur gear 5 is axially arranged between the second bevel gear 3 and the third bevel gear 4, making the path of power from the input side to the output side more compact. Compared with the conventional arrangement of placing the spur gear 5 outside the bevel gears, this arrangement shortens the axial length of the gearbox, which is beneficial for the miniaturization design of the entire machine.

[0055] According to an embodiment of this application, an inner ringless roller bearing 14 is mounted on one side journal of a spur gear 5, and the inner ringless roller bearing 14 is suitable for providing rotational support for the spur gear 5.

[0056] According to the embodiments of this application, the inner ring-less roller bearing 14 is directly mounted on one side of the journal of the spur gear 5, with the roller in contact with the journal surface. This eliminates the need for an inner ring, reducing the number of parts. At the same time, the journal directly serves as the raceway, providing higher support rigidity and improving reliability.

[0057] In some specific embodiments, the journal surface is hardened so that it can be used directly as a raceway. This configuration saves the radial space occupied by the bearing inner ring, while improving support stiffness and reducing cumulative assembly errors of parts.

[0058] According to an embodiment of this application, the aforementioned transmission structure further includes an input bevel gear 1, which is suitable for connection with the main shaft of a gas turbine. The input bevel gear 1 is supported on a bearing housing 12 by a flanged angular contact ball bearing 13.

[0059] According to an embodiment of this application, the input bevel gear 1 is supported on the bearing housing 12 by a flanged angular contact ball bearing 13. The flange connection facilitates the installation and removal of the bearing. The bearing bears the radial force and axial thrust from the spindle, transferring the load to the integrated bearing housing 12, thus ensuring the rotational accuracy and positioning stability of the input end.

[0060] According to an embodiment of this application, the aforementioned transmission structure further includes a spur gear set, which includes a first accessory spur gear 6, a second accessory spur gear 7, and a third accessory spur gear 9. The spur gear set is connected to a horizontal transmission shaft and is suitable for driving a fuel pump, an oil pump, and a motor, respectively.

[0061] According to an embodiment of this application, three accessory spur gears are respectively connected to a horizontal drive shaft, each independently driving the fuel pump, oil pump, and motor. This multi-output configuration can simultaneously meet the speed and power requirements of different accessories, avoiding the intermediate link of single output re-splitting, and improving the integration and power density of the transmission system.

[0062] According to an embodiment of this application, the aforementioned transmission structure further includes an idler wheel 8, which is configured to mesh with a spur gear set.

[0063] According to an embodiment of this application, the idler gear 8 meshes with a spur gear set to change the transmission direction or compensate for the center distance.

[0064] In some specific embodiments, the idler gear 8 is positioned between the spur gears, allowing the starter or generator to be placed in a suitable position in the gearbox, improving the flexibility of accessory layout and reducing the number of parts.

[0065] In some more specific embodiments, the clamping nut 15 is located at the end of the central drive shaft 10, i.e., at the end of the horizontal drive shaft (such as the shaft where the spur gear 5 is located). The clamping nut 15 axially fixes the parts on the shaft, which can precisely control the axial clearance between the bearing and the gear, and prevent the parts from loosening due to axial force. Compared with retaining rings or shaft shoulders for positioning, the clamping nut has the advantages of adjustable locking force and convenient disassembly, which is conducive to improving the assembly accuracy and operational stability of the transmission system, and reducing tooth surface wear and vibration noise caused by axial movement.

[0066] In some more specific embodiments, the deep groove ball bearing 16 is mounted on the right journal of a horizontal transmission assembly (such as a spur gear 5), forming a double-support with the inner ringless roller bearing 14, which shares part of the radial force, reduces the deflection of the transmission shaft, and ensures the uniformity of gear meshing.

[0067] In some more specific embodiments, the deep groove ball bearing has a sealing structure that prevents lubricant leakage and contaminant intrusion, thereby improving the bearing's service life and the overall reliability of the transmission system.

[0068] It should be noted that the described embodiments are merely some, not all, of the embodiments described in this application. Other embodiments obtained by those skilled in the art based on the embodiments described in this application without inventive effort are all within the scope of protection of this application.

[0069] In some specific embodiments, in the operating condition of the gas turbine accessory gearbox, the transmission process of this transmission structure includes:

[0070] During the engine start-up phase, the starter motor drives the third accessory spur gear 9 to rotate. The power is transmitted sequentially through the idler gear 8, the spur gear 5, the second bevel gear 3, and the third bevel gear 4, which drives the central drive shaft 10 and the first bevel gear 2 to rotate. The first bevel gear 2 then drives the input bevel gear 1 to rotate. The input bevel gear 1 drives the gas turbine main shaft to the ignition speed through the spline, thus achieving start-up.

[0071] During normal engine operation, the gas turbine main shaft drives the input bevel gear 1 to rotate via splines. The input bevel gear 1 drives the first bevel gear 2 to rotate. The first bevel gear 2 transmits power to the second bevel gear 3 and the third bevel gear 4 via the central drive shaft 10. The power is then split by the spur gear 5 and drives the first accessory spur gear 6, the second accessory spur gear 7, and the third accessory spur gear 9 via the idler gear 8, thereby driving the fuel pump, the lubricating oil pump, and the motor.

[0072] Throughout the operation, the bearing housing 12 is integrally formed through additive manufacturing, and its internal integrated lubrication circuit lubricates the double-row angular contact ball bearing 11 and the inner ringless roller bearing 14; the spline connection between the central drive shaft 10 and the first bevel gear 2 is used to isolate the additional stress caused by thermal deformation and misalignment; the double-row angular contact ball bearing 11 bears axial and lateral loads; the rollers of the inner ringless roller bearing 14 directly contact the journal of the horizontal transmission assembly, providing support for the spur gear 5.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A transmission structure for a gas turbine accessory gearbox, comprising: The bearing housing (12) is constructed to be integrally formed by additive manufacturing; The central drive shaft (10) is configured to be inclined on the bearing housing (12) for transmitting power; The first bearing unit rotatably supports one end of the central drive shaft (10) so that the central drive shaft (10) is fixedly connected to the bearing seat (12); The second bearing unit rotatably supports the horizontal transmission assembly within the gas turbine accessory gearbox. The second bearing unit is a ringless roller bearing (14), and the rollers of the ringless roller bearing (14) directly contact one journal of the horizontal transmission assembly.

2. The transmission structure according to claim 1, wherein, The first bearing unit is a double-row angular contact ball bearing (11). The double-row angular contact ball bearing (11) is fitted onto the meshing end of the central drive shaft (10) and the bearing housing (12). The outer ring of the double-row angular contact ball bearing is fixedly connected to the bearing housing (12) through the flange edge.

3. The transmission structure according to claim 1 further includes: The first bevel gear (2) is mounted on the central drive shaft (10) via a spline connection. It is suitable for transmitting torque and allows relative displacement between the central drive shaft (10) and the first bevel gear (2) to isolate misalignment and thermal deformation stress caused by working conditions.

4. The transmission structure according to claim 2, wherein, The bearing housing (12) is provided with a lubrication oil passage, which extends to the double-row angular contact ball bearing (11) and the inner ringless roller bearing (14).

5. The transmission structure according to claim 1, wherein, The outer ring of the roller bearing (14) without an inner ring is provided with a flange for fixed connection with the gas turbine accessory gearbox.

6. The transmission structure according to claim 1 further includes: The second bevel gear (3), the third bevel gear (4), and the spur gear (5) arranged axially between the second bevel gear (3) and the third bevel gear (4).

7. The transmission structure according to claim 6, wherein, The inner ringless roller bearing (14) is fitted onto one side journal of the spur gear (5), and the inner ringless roller bearing (14) is suitable for providing rotational support for the spur gear (5).

8. The transmission structure according to claim 1, wherein, It also includes an input bevel gear (1) suitable for connection to the main shaft of the gas turbine, the input bevel gear (1) being supported on the bearing housing (12) by a flanged angular contact ball bearing (13).

9. The transmission structure according to any one of claims 1-8 further includes a spur gear set, the spur gear set including a first accessory spur gear (6), a second accessory spur gear (7) and a third accessory spur gear (9), the spur gear set being connected to the horizontal transmission assembly for driving the fuel pump, the lubricating oil pump and the motor respectively.

10. The transmission structure according to claim 9 further includes an idler wheel (8) configured to mesh with the spur gear set.

Images