Auxiliary device and method for bearing assembly during butt joint of aero-engine transmission casing

Abstract

The invention belongs to the technical field of aero-engine assembly, and provides an auxiliary device and method for bearing assembly during aero-engine transmission casing butt joint, and the device comprises a positioning supporting assembly, a gear fixing assembly, a press fitting assembly and a rotary driving assembly. The positioning and supporting assembly is detachably mounted on the mounting edge of the lower transmission casing; the gear fixing assembly is arranged in the center area of the positioning and supporting assembly and matched with the transmission gear to exert axial and circumferential constraint on the transmission gear. The press-fitting assembly is in threaded connection with the threaded shaft end of the transmission gear, and the lower end of the press-fitting assembly is provided with an inner ring part and an outer ring part which abut against the inner ring end face and the outer ring end face of a to-be-assembled second bearing correspondingly. The rotation driving assembly is connected to the upper portion of the press-fitting assembly and transmits externally-applied rotation torque to the press-fitting assembly. Complete fixation of the transmission gear and synchronous press fitting of the inner ring and the outer ring of the bearing are achieved through structural design, a quantitative detection means is combined, the assembly precision and reliability are ensured, and the assembly efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine assembly technology, and relates to an auxiliary device and method for bearing assembly during the docking of aero-engine transmission housing. Background Technology

[0002] During the final assembly of an aero-engine, the precise installation of multiple transmission gears is required when the transmission housing is docked with the core engine. Among these processes, heat-fitting the bearings to the transmission gear shaft and ensuring they are properly pressed in place without tilting is a critical step that affects the operational stability and lifespan of the transmission system.

[0003] Traditional assembly methods often involve directly heating the bearing and then fitting it onto the shaft end, using simple tooling or manual hammering for press-fitting. However, this method has the following prominent problems: 1. Unstable transmission gears: During the press-fitting process, the transmission gears are prone to axial movement or circumferential rotation, which can cause the bearings to fail to be accurately positioned or even damage the mating surfaces. 2. Uneven force causing misalignment: Traditional pressing tools often only apply force to the inner or outer ring of the bearing, resulting in asynchronous force on the inner and outer rings. This can easily cause the bearing to tilt, affecting rotational accuracy and causing abnormal wear. 3. Lack of quantitative testing methods: Whether the pressing is in place mainly relies on experience to judge, and there is a lack of quantifiable testing methods, making it difficult to ensure batch consistency; 4. Low operating efficiency and poor safety: Manual operation is labor-intensive, the impact force is not easy to control, and there are safety hazards.

[0004] Therefore, there is an urgent need for a dedicated auxiliary device and matching assembly method that integrates positioning, synchronous pressing and process detection. Summary of the Invention

[0005] To address the technical problems in existing bearing assembly processes, such as unstable transmission gears, easy bearing tilting, and difficulty in controlling press-fit quality, this invention discloses an auxiliary device for bearing assembly during the docking of aero-engine transmission housings. This device enables smooth, synchronous, and precise press-fitting of bearings, and provides detectability of the assembled bearing, thereby improving assembly efficiency and reliability. Specifically, the auxiliary device includes a positioning support assembly, a gear fixing assembly, a press-fitting assembly, and a rotary drive assembly.

[0006] The positioning support assembly is detachably mounted on the mounting side of the lower transmission housing; The gear fixing assembly is located in the central area of ​​the positioning support assembly and cooperates with the transmission gear to apply axial and circumferential constraints to the transmission gear during bearing assembly. The gear fixing assembly is provided with an axial boss for axial constraint of the first bearing. The press-fit assembly is threaded to the threaded shaft end of the transmission gear, and has an inner ring and an outer ring at the lower end. The inner ring is used to press against the inner ring end face of the second bearing to be assembled, and the outer ring is used to press against the outer ring end face of the second bearing. The rotary drive assembly is connected to the upper part of the pressing assembly and transmits the externally applied rotational torque to the pressing assembly.

[0007] Furthermore, the positioning support assembly includes a mounting plate, positioning pins, and a nut. The mounting plate is positioned with the lower transmission housing by at least two of the positioning pins, and then fixed to the mounting edge of the lower transmission housing by the nut.

[0008] Furthermore, the gear fixing assembly includes a splined shaft, which is fixed in the central through hole of the positioning support assembly by screws; The splined shaft is inserted into the internal spline of the transmission gear, and one end of the splined shaft is provided with an axial boss that abuts against the end face of the inner ring of the first bearing.

[0009] Furthermore, the press-fit assembly includes a slotted nut, the lower end face of which is provided with an annular groove, the annular groove dividing the slotted nut into a coaxial inner ring portion and an outer ring portion, the diameter of the inner ring portion being smaller than the outer diameter of the inner ring of the second bearing, and the diameter of the outer ring portion being larger than the inner diameter of the outer ring of the second bearing.

[0010] Furthermore, the rotary drive assembly includes a slotted sleeve and a handle. The lower end of the slotted sleeve is provided with a plurality of protrusions that match the upper end slot of the press-fit assembly. The handle is detachably inserted into a hole on the slotted sleeve.

[0011] Furthermore, the rotary drive assembly also includes a perforated top plate welded to the top of the slotted sleeve, wherein the perforated top plate has a through square hole in the middle as a force-bearing interface.

[0012] Furthermore, the perforated top plate and the slotted sleeve are connected by welding or integral molding.

[0013] This invention also provides a bearing assembly method for docking aero-engine transmission housing, using the aforementioned auxiliary device to assemble the bearing into place. The method includes the following steps: S1. Assemble the positioning support assembly onto the lower transmission housing, insert the splined shaft of the gear fixing assembly into the inner spline of the transmission gear, lock the transmission gear axially and circumferentially, and constrain the end face of the inner ring of the first bearing. S2. Detect the distance H between the thread end face of the transmission gear and the shoulder of the second bearing mounting position; S3. Place the second bearing to be assembled in a heating furnace and heat it to the set temperature and keep it at that temperature for a given time. At the same time, locally heat the corresponding bushing area of ​​the upper casing to the preset temperature. S4. The heated second bearing is mounted on the transmission gear shaft, and a press-fit assembly is assembled on the upper end face of the transmission gear so that the inner ring and outer ring of the press-fit assembly press against the inner ring and outer ring of the bearing respectively. The rotary drive assembly is struck to apply an initial press-fit force. S5: After the press-fitting assembly is fully screwed into the transmission gear, a press-fitting force is applied by rotating the drive assembly until the bearing is fully in contact with the shaft shoulder; S6. Remove the auxiliary device and select no less than four measuring points evenly in the circumferential direction of the second bearing. Measure the height h from the bearing inner ring end face to the shaft end face at each measuring point. Calculate the difference B2 of each measuring point using the formula Hh. Compare each B2 with the actual measured width B1 of the second bearing. If |B2–B1| of all measuring points is less than or equal to the tolerance Δ, the bearing is judged to be properly pressed and without tilting. Otherwise, the assembly is judged to be unqualified and needs to be reheated for reassembly.

[0014] Furthermore, the heating temperature of the second bearing is 70-80°C, and the holding time is 20-30 minutes; the local heating temperature of the lower casing bushing area is 60-80°C.

[0015] Furthermore, if |B2–B1| > Δ at any measuring point, it is determined that the bearing has an assembly misalignment and needs to be disassembled and reheated for reassembly.

[0016] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: 1. High stability: The combination structure of spline shaft and mounting plate effectively locks the axial and circumferential degrees of freedom of the transmission gear, avoiding press-fit disturbance; 2. Synchronous press fitting: The double-ring design of the slotted nut ensures that the inner and outer rings of the bearing are subjected to force synchronously, preventing tilting caused by uneven load. 3. Flexible operation: The rotary drive assembly combines impact pressing and manual fine adjustment functions to meet the needs of different assembly stages; 4. Quality controllable: A quantitative detection method based on the comparison of Hh difference and B1 is proposed, which can objectively judge the pressing status and eliminate human error. 5. Simple structure and strong versatility: The modular design facilitates maintenance and adaptation to different engine models, and is suitable for on-site assembly environments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an overall schematic diagram of the auxiliary device for bearing assembly during the docking of the aero-engine transmission housing according to the present invention; Figure 2 This is a flowchart of the bearing assembly method during the docking of the aero-engine transmission housing according to the present invention; The components include: 1. Mounting plate; 2. Locating pin; 3. Splined shaft; 4. Screw; 5. Nut; 6. Slotted nut; 7. Handle; 8. Slotted sleeve; 9. Perforated top plate; 100. Lower transmission housing; 200. Transmission gear; 300. Second bearing; 400. First bearing; 500. Upper housing. Detailed Implementation

[0019] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0020] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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 the invention and simplifying the description, and do not indicate or imply that the device 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 limiting the invention.

[0022] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0024] This invention discloses an auxiliary device for bearing assembly during the docking of an aero-engine transmission housing. The auxiliary device includes a positioning support assembly, a gear fixing assembly, a pressing assembly, and a rotary drive assembly.

[0025] Among them, see Figure 1 As shown, the positioning support assembly is detachably mounted on the mounting side of the lower transmission housing 100, providing a mounting reference for the overall structure; The gear fixing assembly is located in the central area of ​​the positioning support assembly and cooperates with the transmission gear 200. It is used to apply axial and circumferential constraints to the transmission gear 200 during the bearing assembly process. The gear fixing assembly is provided with an axial boss that axially constrains the first bearing 400 to prevent it from moving or rotating. The press-fit assembly is threaded to the threaded shaft end of the transmission gear 200. The lower end is provided with an inner ring and an outer ring. The inner ring is used to press against the inner ring end face of the second bearing 300 to be assembled, and the outer ring is used to press against the outer ring end face of the second bearing 300, so as to realize synchronous force press-fit of the inner and outer rings. The rotary drive assembly is connected to the upper part of the pressing assembly and transmits the externally applied rotational torque to the pressing assembly to drive it to move axially to complete the pressing operation.

[0026] In addition, the top of the rotary drive assembly is provided with a force-receiving interface for receiving impact forces such as hammering to achieve initial rapid pressing, or for connecting a torque wrench to achieve precise torque control.

[0027] Further, see Figure 1 As shown, the positioning support assembly includes a mounting plate 1, positioning pins 2, and nuts 5. The mounting plate 1 is positioned with the lower transmission housing 100 by at least two positioning pins 2, and then fixed to the mounting edge of the lower transmission housing 100 by the nuts 5, ensuring high repeatability and stability of the device installation position.

[0028] Further, see Figure 1 As shown, the gear fixing assembly includes a splined shaft 3, which is fixed in the central through hole of the positioning support assembly by screws 4; The splined shaft 3 is inserted into the inner spline of the transmission gear 200 for circumferential locking. One end of the splined shaft 3 is provided with an axial boss that abuts against the inner ring end face of the first bearing 400 to limit the axial displacement of the transmission gear.

[0029] Further, see Figure 1 As shown, the press-fit assembly includes a slotted nut 6. The lower end face of the slotted nut 6 has an annular groove, which divides the slotted nut 6 into a coaxial inner ring portion and an outer ring portion. The diameter of the inner ring portion is smaller than the outer diameter of the inner ring of the second bearing 300, and this inner ring portion only acts on the inner ring of the bearing. The diameter of the outer ring portion is larger than the inner diameter of the outer ring of the second bearing 300, and this outer ring portion only acts on the outer ring of the bearing. The inner and outer ring portions divided by the annular groove allow for simultaneous pressing of the inner and outer rings of the bearing during tightening, avoiding assembly tilting caused by uneven loading.

[0030] Further, see Figure 1 As shown, the rotary drive assembly includes a slotted sleeve 8 and a handle 7. The lower end of the slotted sleeve 8 is provided with multiple protrusions that match the upper end slot of the pressing assembly. The pressing assembly and the slotted sleeve 8 are coupled and connected in the circumferential direction through the protrusions. The handle 7 is detachably inserted into the insertion hole on the slotted sleeve 8 for applying rotational torque manually or by a robotic arm, so as to achieve a smooth and controllable pressing process.

[0031] Furthermore, see Figure 1 As shown, the rotary drive assembly also includes a perforated top plate 9 welded to the top of the slotted sleeve 8. The perforated top plate 9 has a through square hole in the middle as a force-bearing interface, which is used to receive the impact force of the hammering tool to complete the initial pressing, or to connect an electric / pneumatic / manual torque wrench to achieve precise torque control in the final tightening stage.

[0032] Furthermore, the perforated top plate 9 and the slotted sleeve 8 are connected by welding or integral molding to ensure structural strength and force transmission efficiency.

[0033] This invention also provides a bearing assembly method for docking aero-engine transmission housing, using the aforementioned auxiliary device to assemble the bearing into place. See [link to relevant documentation]. Figure 2 As shown, the method includes the following steps: S1. Assemble the positioning support assembly onto the lower transmission housing 100, insert the splined shaft 3 of the gear fixing assembly into the inner spline of the transmission gear 200, lock the transmission gear 200 axially and circumferentially, and axially constrain the inner ring end face of the first bearing 400. S2. Detect the distance H between the threaded end face of the transmission gear 200 and the shoulder of the mounting position of the second bearing 300; S3. Place the second bearing 300 to be assembled in a heating furnace and heat it to the set temperature and keep it at the temperature for a given time. At the same time, locally heat the bushing area of ​​the upper casing 500 to the preset temperature. S4. The heated second bearing 300 is mounted on the shaft of the transmission gear 200. A press-fit assembly is installed on the upper end face of the transmission gear 200 so that the inner ring and outer ring of the press-fit assembly press against the inner and outer rings of the bearing respectively. The rotary drive assembly is struck to apply an initial press-fit force. S5: After the press-fitting assembly is fully screwed into the transmission gear 200, a press-fitting force is applied by rotating the drive assembly until the bearing is fully in contact with the shaft shoulder. S6. Remove the auxiliary device and select no less than four measuring points evenly in the circumferential direction of the second bearing 300. Measure the height h from the bearing inner ring end face to the shaft end face at each measuring point. Calculate the difference B2 of each measuring point using the formula Hh. Compare each B2 with the actual width B1 of the second bearing 300 as measured. If |B2–B1| ≤ tolerance Δ of all measuring points, the bearing is judged to be properly pressed and without tilting; otherwise, the assembly is judged to be unqualified and needs to be reheated for assembly.

[0034] Furthermore, the heating temperature of the second bearing 300 is 70-80°C, and the holding time is 20-30 minutes; the local heating temperature of the bushing area of ​​the lower casing 500 is 60-80°C.

[0035] Furthermore, if |B2–B1| > Δ at any measuring point, it is determined that the bearing has an assembly misalignment. It needs to be disassembled and reassembled by heating. Forced correction is strictly prohibited to avoid abnormal wear or premature failure of the bearing during operation.

[0036] Furthermore, in step S4, the impact force can be applied by striking the top plate 9 of the opening with a rubber hammer or a copper rod, with 3 to 5 impacts, each with uniform force, to prevent local stress concentration. Furthermore, in step S5, when the handle 7 is rotated manually or by a robotic arm using torque control, the rotation speed is controlled within 10 to 15 rpm to ensure a smooth and impact-free pressing process.

[0037] The embodiments of the present invention achieve the following technical effects: 1. High stability: The combination structure of spline shaft and mounting plate effectively locks the axial and circumferential degrees of freedom of the transmission gear, avoiding press-fit disturbance; 2. Synchronous press fitting: The double-ring design of the slotted nut ensures that the inner and outer rings of the bearing are subjected to force synchronously, preventing tilting caused by uneven load. 3. Flexible operation: The rotary drive assembly combines impact pressing and manual fine adjustment functions to meet the needs of different assembly stages; 4. Quality controllable: A quantitative detection method based on the comparison of Hh difference and B1 is proposed, which can objectively judge the pressing status and eliminate human error. 5. Simple structure and strong versatility: The modular design facilitates maintenance and adaptation to different engine models, and is suitable for on-site assembly environments.

[0038] Obviously, those skilled in the art should understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Various modifications and variations of the embodiments of the present invention are possible for 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 protection scope of the present invention.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An auxiliary device for bearing assembly during the interfacing of an aeroengine gearbox, characterized in that, Comprise: Positioning support assembly, gear fixing assembly, press-fitting assembly and rotary drive assembly; The positioning support assembly is detachably mounted on the mounting edge of the lower transmission case (100); The gear fixing assembly is arranged in the central region of the positioning support assembly and cooperates with the transmission gear (200) to apply axial and circumferential constraints to the transmission gear (200) during bearing assembly, and an axial boss for axially constraining the first bearing (400) is arranged on the gear fixing assembly; The press-fitting assembly is threadedly connected to the threaded shaft end of the transmission gear (200), and the lower end is provided with an inner ring portion and an outer ring portion, the inner ring portion is used to press the inner ring end face of the second bearing (300) to be assembled, and the outer ring portion is used to press the outer ring end face of the second bearing (300); The rotary drive assembly is connected to the upper part of the press-fitting assembly to transmit the externally applied rotary torque to the press-fitting assembly.

2. The auxiliary device for bearing assembly during the aero-engine gearbox docking, according to claim 1, characterized in that, The positioning support assembly comprises a mounting plate (1), a positioning pin (2) and a nut (5), the mounting plate (1) is positioned with the lower transmission case (100) through at least two positioning pins (2), and then fixed on the mounting edge of the lower transmission case (100) through the nut (5).

3. The apparatus of claim 1, wherein, The gear fixing assembly comprises a spline shaft (3), and the spline shaft (3) is fixed in the central through hole of the positioning support assembly through a screw (4); The spline shaft (3) is inserted into the inner spline of the transmission gear (200), and one end of the spline shaft (3) is provided with the axial boss for abutting against the inner ring end face of the first bearing (400).

4. The apparatus of claim 1, wherein, The press-fitting assembly comprises a slotted nut (6), and the lower end face of the slotted nut (6) is provided with an annular groove, the annular groove divides the slotted nut (6) into the coaxial inner ring portion and the outer ring portion, the diameter of the inner ring portion is smaller than the outer diameter of the inner ring of the second bearing (300), and the diameter of the outer ring portion is greater than the inner diameter of the outer ring of the second bearing (300).

5. The apparatus of claim 1, wherein, The rotary drive assembly comprises a slotted sleeve (8) and a handle (7), the lower end of the slotted sleeve (8) is provided with a plurality of convex grooves matched with the upper end groove of the press-fitting assembly, and the handle (7) is detachably arranged in the insertion hole of the slotted sleeve (8).

6. The auxiliary device for bearing assembly during the aero-engine gearbox docking, according to claim 5, characterized in that, The rotary drive assembly further comprises an open-top plate (9) welded on the top of the slotted sleeve (8), and a square hole as a force interface is arranged in the middle of the open-top plate (9).

7. The auxiliary device for bearing assembly during the aeroengine gearbox docking, according to claim 6, characterized in that, The open-top plate (9) and the slotted sleeve (8) are connected by welding or one-piece forming.

8. A method of bearing assembly for an aeroengine gearbox during docking, characterised in that, Comprise: S1, assemble the positioning support assembly to the lower transmission case (100), insert the spline shaft (3) of the gear fixing assembly into the inner spline of the transmission gear (200), axially and circumferentially lock the transmission gear (200), and axially constrain the inner ring end face of the first bearing (400); S2, detect the distance H between the threaded end face of the transmission gear (200) and the shaft shoulder of the second bearing (300) installation position; S3, the second bearing (300) to be assembled is placed in a heating furnace to heat to a set temperature and keep warm for a given time, while the corresponding bushing area of the upper gearbox shell (500) is locally heated to a preset temperature; S4, the heated second bearing (300) is sleeved on the shaft of the transmission gear (200), and a press-fitting assembly is assembled on the upper end surface of the transmission gear (200), so that the inner ring part and the outer ring part of the press-fitting assembly are tightly pressed against the inner ring and the outer ring respectively, and the initial press-fitting force is applied by knocking the rotary driving assembly; S5: When the press-fitting assembly is completely rotated into the transmission gear (200), the press-fitting force is applied by the rotary driving assembly until the bearing is completely attached to the shaft shoulder; S6, remove the auxiliary device, evenly select not less than four measuring points in the circumferential direction of the second bearing (300), measure the height h from the inner ring end surface of the bearing to the shaft end surface at each measuring point, calculate the difference B2 of each measuring point by the formula H-h, and compare each B2 with the actual width B1 of the second bearing (300); if |B2-B1|≤tolerance Δ for all measuring points, it is determined that the bearing is press-fitted in place and has no inclination; otherwise, the assembly is unqualified and needs to be re-heated and assembled.

9. The method of bearing assembly for an aeroengine drive gearbox interface at time of mating according to claim 8, wherein, The heating temperature of the second bearing (300) is 70-80℃, and the holding time is 20-30 minutes; the local heating temperature of the bushing area of the lower gearbox shell (500) is 60-80℃.

10. The method of bearing assembly for an aeroengine drive gearbox interface at time of mating according to claim 8, wherein, If |B2-B1| > Δ for any one measuring point, it is determined that the bearing is assembled with inclination and needs to be disassembled and re-heated and assembled.

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