A method for assembling bevel gear pair of an aero-engine

Abstract

The present application belongs to the technical field of mechanical assembly, and particularly relates to a bevel gear pair assembling method for an aero-engine, which comprises the following steps: initially selecting an axial gap adjusting pad and an engagement gap adjusting pad, and installing two bevel gears to form the bevel gear pair; then measuring the engagement gap and coloring state of the bevel gear pair under a preset axial load; and finally adjusting the thickness of the engagement gap adjusting pad according to a corresponding ratio, so that the engagement gap, coloring state and axial gap of the bevel gear pair meet the assembling requirements. The present application can guide inexperienced personnel to quickly assemble and adjust the bevel gear pair after simple learning, thereby reducing the disassembly and assembly times of aero-engine parts and the assembling and adjusting time of the bevel gear pair.

Description

Technical Field

[0001] This invention belongs to the field of mechanical assembly technology, and specifically relates to a method for assembling and adjusting a bevel gear pair for an aero-engine. Background Technology

[0002] The basic requirements for the assembly and adjustment of bevel gears in a certain aircraft engine include: the axial clearance, meshing clearance, and color mark adjustment must be completed simultaneously during the assembly and adjustment of bevel gears. The axial clearance should be calculated without eliminating bearing clearance. The changes in the axial clearance, meshing clearance, and color mark of the same pair of bevel gears are interrelated, so comprehensive analysis is required when making adjustments.

[0003] In the existing technology, process adjustment shims are used instead of formal parts when assembling and adjusting bevel gears. Due to the limitations of the above basic requirements, workers need to rely on experience to select appropriate thickness meshing clearance adjustment shims and axial clearance adjustment shims to ensure meshing clearance, axial clearance and color marks after assembly. This is difficult to operate, requires multiple disassembly and assembly, and is too dependent on personnel experience. Summary of the Invention

[0004] In view of this, the present invention provides a method for assembling and adjusting bevel gear pairs in aero-engines, which can guide inexperienced personnel to quickly assemble and adjust bevel gear pairs after simple learning, thereby reducing the number of disassembly and assembly operations of aero-engine parts, reducing the assembly and adjustment time of bevel gear pairs, and lowering the assembly and adjustment threshold.

[0005] To achieve the above-mentioned technical objectives, the specific technical solution adopted by the present invention is as follows:

[0006] A method for assembling and adjusting a bevel gear pair for an aircraft engine, wherein the bevel gear pair includes two bevel gears meshing with a shaft angle of 90°;

[0007] Both the meshing clearance adjusting shim and the axial clearance adjusting shim act on the coaxial bearing on which the bevel gears are mounted, and are used to adjust the meshing clearance and axial clearance between the two bevel gears, respectively; the bevel gear pair assembly and adjustment method includes the following steps:

[0008] S101: Initially select and match the axial clearance adjustment shim and the meshing clearance adjustment shim, and install the two bevel gears to form the bevel gear pair;

[0009] S102: Measure the meshing clearance of the bevel gear pair under a preset axial load; apply a colorant to both sides of all teeth of the driving gear of the bevel gear pair;

[0010] Under a preset axial load and in the braking state of the driven bevel gear, the driving bevel gear in the bevel gear pair is rotated, and the coloring state of the bevel gear pair is obtained based on the adhesion state of the colorant on the two tooth surfaces of the driven bevel gear of the bevel gear pair.

[0011] S103: If the meshing gap does not meet the requirements, the thickness of the meshing gap adjusting shim is changed. The thickness adjustment range of the meshing gap adjusting shim is equal to 0.4-0.5 times the meshing gap to be adjusted. After the meshing gap meets the requirements, if the coloring state does not meet the requirements, the thickness of the meshing gap adjusting shim is adjusted again. The thickness adjustment range of the meshing gap adjusting shim is equal to 10 times the change in the C value of the imprint to be adjusted.

[0012] Furthermore, when adjusting the coloring state, if the thickness of one meshing gap adjustment shim is increased, the thickness of the other meshing gap adjustment shim is decreased by the same amount.

[0013] When adjusting the coloring state, if the thickness of one meshing gap adjustment shim is reduced, the thickness of the other meshing gap adjustment shim is increased by the same amount.

[0014] Furthermore, the meshing clearance adjusting shim is disposed on the side of the coaxial bearing near the teeth of the bevel gear; the meshing clearance adjusting shim simultaneously contacts the bevel gear and the coaxial bearing;

[0015] The axial clearance adjusting shim is disposed on the side of the coaxial bearing away from the teeth of the bevel gear; the meshing clearance adjusting shim simultaneously contacts the coaxial bearing and the limiting mounting edge of the coaxial bearing.

[0016] Furthermore, the normal pressure angle between a pair of bevel gears is 18 to 22°, and the cone angle between a pair of bevel gears is 40° to 50°.

[0017] Furthermore, the thickness of the axial clearance adjusting shim is initially selected based on the following formula:

[0018] N2=H2-(B+С2)-D

[0019] In the formula:

[0020] N2—Theoretical calculated thickness of the axial clearance adjustment shim;

[0021] H2—The depth dimension of the collar of the coaxial bearing;

[0022] C2—Dimension of the protruding edge of the limiting mounting edge;

[0023] B—Inner ring width dimension of the coaxial bearing;

[0024] D—The theoretical axial clearance of the bevel gear.

[0025] Furthermore, the thickness of the meshing clearance adjusting shim is selected based on the following formula:

[0026] N1 = E - (A + B + N2 + C1 + D1) + L

[0027] In the formula:

[0028] The distance between the mating surface of the mounting housing of the E-bevel gear and the centerline of the hole for mounting the bevel gear; the distance between the support end face of the A-bevel gear and the top of the gear cone;

[0029] B - Inner ring width dimension of coaxial gear bearing;

[0030] N1 - Thickness of the meshing clearance adjustment shim;

[0031] C1 - Dimensions of the protruding part of the limiting mounting edge;

[0032] D1 - The dimension of the protruding edge from the housing mating surface to the limiting mounting edge;

[0033] The axial clearance of an L-coaxial bearing is half of its axial clearance.

[0034] Theoretical calculated thickness of N2-axial clearance adjustment shim.

[0035] Furthermore, the colorant is orange-red red lead powder.

[0036] Furthermore, the colorant comprises industrial lead tetroxide and 8B lubricating oil in a weight ratio of 1:1.

[0037] Furthermore, the preset axial load is used to remove the axial clearance of the bearing between the two bevel gears.

[0038] By adopting the above technical solution, the present invention can bring the following beneficial effects:

[0039] This invention can guide inexperienced personnel to quickly assemble and adjust bevel gear pairs after a simple learning process, reducing the number of disassembly and assembly operations, shortening the assembly and adjustment time of bevel gear pairs, and lowering the assembly and adjustment threshold. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A flowchart for the assembly and adjustment method of bevel gear pairs for aero engines;

[0042] Figure 2 A schematic diagram illustrating the working principle of a coaxial bearing press-fitting tool;

[0043] Figure 3 A schematic diagram of the tooling for measuring meshing clearance;

[0044] Figure 4 A schematic diagram of the base coloring imprint;

[0045] Figure 5 This is a schematic diagram of the bevel gear pair in its installed state.

[0046] Figure 6 A schematic diagram of a colored imprint on a driven bevel gear;

[0047] Figure 7 A schematic diagram of a colored imprint on a driven bevel gear;

[0048] Figure 8 A schematic diagram of a colored imprint on a driven bevel gear;

[0049] The components include: 1. bevel gear; 2. coaxial bearing; 3. meshing clearance adjusting shim; 4. axial clearance adjusting shim; and 5. limiting mounting edge. Detailed Implementation

[0050] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0051] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure 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 disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0052] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0053] 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.

[0054] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0055] In one embodiment of the present invention, a method for adjusting a bevel gear pair in an aero-engine is proposed. The bevel gear pair includes two bevel gears 1 meshing at a 90° angle between their shafts. A meshing clearance adjusting shim 3 and an axial clearance adjusting shim 4 both act on a coaxial bearing 2 mounted on the bevel gears 1, respectively adjusting the meshing clearance and axial clearance between the two bevel gears 1. Figure 1 As shown, the assembly and adjustment method for bevel gear pairs includes the following steps:

[0056] S101: Initially select and match the meshing clearance adjusting shim 3 and the axial clearance adjusting shim 4, install the two bevel gears 1 to form a gear pair, as follows: Figure 5 As shown;

[0057] S102: Measure the meshing clearance of the gear pair under a preset axial load; based on the colorant applied to both sides of all teeth of the driving gear of the bevel gear pair, rotate the driving bevel gear in the gear pair under the preset axial load and the braking state of the driven bevel gear 1, and obtain the coloring state of the bevel gear pair based on the adhesion state of the colorant on the two tooth surfaces of the driven bevel gear of the bevel gear pair.

[0058] S103: If the meshing clearance does not meet the requirements, change the thickness of the meshing clearance adjusting shim 3. The thickness adjustment range of the meshing clearance adjusting shim 3 is equal to 0.4-0.5 times the meshing clearance to be adjusted. If the coloring state does not meet the requirements after the meshing clearance meets the requirements, adjust the thickness of the meshing clearance adjusting shim 3 again. The thickness adjustment range of the meshing clearance adjusting shim 3 is equal to 10 times the change in the C value of the imprint to be adjusted.

[0059] In this embodiment, after the meshing clearance is adjusted to be qualified, when adjusting the coloring state, if the thickness of the meshing clearance adjustment pad 3 of one bevel gear is increased, the thickness of the meshing clearance adjustment pad 3 of the other bevel gear is reduced by the same amount.

[0060] In this embodiment, after the meshing gap is adjusted to be qualified, when adjusting the coloring state, if the thickness of one meshing gap adjusting pad 3 is reduced, the thickness of another meshing gap adjusting pad 3 is increased by the same amount.

[0061] In this embodiment, the meshing clearance adjusting shim 3 is disposed on the side of the coaxial bearing 2 near the teeth of the bevel gear 1; the meshing clearance adjusting shim 3 contacts both the bevel gear 1 and the coaxial bearing 2.

[0062] In this embodiment, the axial clearance adjusting shim 4 is disposed on the side of the coaxial bearing 2 away from the teeth of the bevel gear 1; the meshing clearance adjusting shim 3 simultaneously contacts the coaxial bearing 2 and the limiting mounting edge 5 of the limiting coaxial bearing 2.

[0063] In this embodiment, the normal pressure angle between a pair of bevel gears 1 is 18 to 22°, and the cone angle between a pair of bevel gears 1 is 40° to 50°.

[0064] In this embodiment, the thickness of the axial clearance adjustment shim 4 is initially selected based on the following formula:

[0065] N2=H2-(B+С2)-D

[0066] In the formula:

[0067] N2—Theoretical thickness of axial clearance adjustment shim 4;

[0068] H2—Depth dimension of the collar of coaxial bearing 2;

[0069] C2—Dimension of the protruding edge of the limiting mounting edge 5;

[0070] B—Inner ring width dimension of coaxial bearing 2;

[0071] D—The theoretical axial clearance of the bevel gear 1.

[0072] In this embodiment, the thickness of the meshing clearance adjustment shim 3 is selected based on the following formula:

[0073] N1 = E - (A + B + N2 + C1 + D1) + L

[0074] In the formula:

[0075] The distance from the mating surface of the mounting housing of E-bevel gear 1 to the center line of the mounting hole of bevel gear 1;

[0076] The distance from the support end face of A-bevel gear 1 to the top of the gear cone;

[0077] B - Inner ring width dimension of coaxial gear bearing 2;

[0078] The thickness of N1-meshing clearance adjustment shim 3;

[0079] C1 - Dimensions of the protruding part of the limiting mounting edge 5;

[0080] D1 - The dimension from the housing mating surface to the protruding edge of the limiting mounting edge 5;

[0081] Half of the axial clearance of L-coaxial bearing 2.

[0082] In this embodiment, the colorant is orange-red lead oxide powder. The colorant comprises industrial lead tetroxide and 8B lubricating oil in a weight ratio of 1:1.

[0083] In this embodiment, a preset axial load is used to remove the axial clearance of the bearing between the two bevel gears 1.

[0084] In this embodiment, before assembling the bevel gear pair, it is necessary to design a calculation formula for the initial thickness of the adjusting shim based on the design structure of the transmission device and the simulation of the engine working state, eliminate the axial clearance of the bearing on the bevel gear, and calculate the initial thickness of the adjusting shim according to the calculation formula.

[0085] In this embodiment, the coaxial bearing 2 is a ball bearing. The unsealing, inspection, cleaning, and heating of the bearing must be carried out before the bearing assembly process. Pre-operation is prohibited. If the assembly is not completed within 4 hours after the bearing is unsealed, the bearing must be resealed to prevent the bearing from being corroded.

[0086] To ensure bearing installation accuracy, specialized tooling should be used for press-fitting during bearing installation. The structure is as follows: Figure 2 This structure features a mandrel positioning function, ensuring that pressure is applied directly to the end face of the bearing's inner ring, guaranteeing uniform bearing force. After press-fitting the bearing, the tooling rebounds under spring force, facilitating disassembly. During bearing press-fitting, impacts and hammering of the bearing are strictly prohibited; the bearing rolling elements and cage must not be subjected to stress. Heat fitting of the bearing is permitted, using oil bath heating to ensure uniform heating. The maximum temperature of the oil bath must not exceed 120℃, and bearing assembly should be completed quickly after heating.

[0087] After the bearing is installed, use a feeler gauge to check the gap between the bearing end face and the bearing bushing shoulder to check whether the bearing is pressed in place. The maximum gap should not exceed 0.02mm.

[0088] After the bearing is installed, its rotational flexibility must be checked, and there should be no obvious obstruction, vibration, noise, or abnormal sounds.

[0089] Design principle of the meshing clearance measuring tool of the present invention

[0090] The measuring fixture is designed for detecting circumferential backlash. It includes functions for applying axial tensile and compressive forces, and features a meshing clearance measuring scale. The position and dimension of the measuring scale on the meshing measuring fixture should be consistent with the large end pitch circle radius of the bevel gear being measured. The structure of the dedicated meshing clearance measuring fixture is as follows: Figure 3 .

[0091] Measurement of meshing clearance in this embodiment:

[0092] Install a special meshing clearance measuring tool on the bevel gear pair consisting of large and small bevel gears 1, and apply an axial tensile force or pressure that meets the design requirements to the large or small gear (for example, when checking the maximum meshing clearance of a certain gear, use a force of (80~100)N to pull the two gears in the direction of disengagement). After eliminating the bearing clearance of bevel gear 1, align the pointer of the indicator with an indication error of no more than 0.01mm vertically with the scale line of the measuring plate of the measuring clearance measuring fixture, and then rotate the unfixed gear in both directions. The maximum reading of the meter is the circumferential clearance.

[0093] Ink stain inspection

[0094] The colorant formulation for this embodiment is as follows:

[0095] Orange-red lead oxide powder (industrial lead tetroxide HG / T 4503) is mixed with 8B lubricating oil in a 1:1 ratio (by weight).

[0096] The method for evaluating colored imprints in this embodiment is as follows:

[0097] The coloring condition of gear color marks is evaluated by the size and position of the color marks. After each pair of bevel gears is assembled, it is necessary to ensure the height C (mm) of the tooth tip without a color mark, the length L (mm) of the color mark, and the difference in the length b (mm) of the color mark on the same gear. Figure 4 As shown in the figure, the ideal coloring imprint under light load is the contact at the smaller end of the middle, that is, the imprint length is about 1 / 2 of the width, and the center of the imprint should be located about 1 / 3 of the tooth width from the smaller end.

[0098] The application requirements of the colorant in this embodiment

[0099] Apply the colorant to the tooth surface of the drive gear using a soft brush. The thin layer of pigment should be applied evenly, and the thickness of the pigment layer should be visually measured to be within the range of 0.005 mm to 0.008 mm according to the sample.

[0100] The axial loading force (preset load) in this embodiment is implemented as follows:

[0101] A pair of bevel gears can be used as Figure 3 The axial load applied by the meshing clearance measuring tool shown

[0102]

[0103] Force is applied to eliminate clearance in the primary and driven wheel bearings.

[0104] This embodiment measures the number of engagement turns during the colored state:

[0105] Before measurement, rotate the driving gear evenly more than 5 times to ensure stable meshing of the bevel gear pair, guarantee the uniformity of the meshing clearance, and ensure that the colored imprint is evenly attached to the tooth surface of the driven gear.

[0106] During the inspection of gear color marks, the color contact marks on the working surface of the driven gear are inspected under the condition that the driven gear is slightly braked by the above-mentioned meshing clearance measuring tool. By applying a certain light load resistance torque, the test tooth surface is guaranteed to maintain stable contact and consistency of color mark size.

[0107] The method for adjusting the color imprint in this embodiment is shown in Table 1.

[0108] Table 1. Adjustment method for coloring marks on a certain bevel gear pair (after meshing clearance adjustment is qualified).

[0109]

[0110] Inspect the colored marks on the tooth surface of the driven bevel gear, and use invisible tape to transfer the tooth surface marks into the assembly record, or record them by means of photos, videos, etc.

[0111] The specific method for adjusting the meshing clearance and color imprint in this embodiment is as follows:

[0112] a) Generally, the meshing clearance should be adjusted first, and the contact imprint should be adjusted after the meshing clearance is qualified.

[0113] b) Adjust the thickness of the shims to ensure proper meshing clearance and color imprints C, K, L, b.

[0114] Requirements: During assembly and adjustment, process adjustment shims of different thickness groups should be used. After the meshing clearance and color imprint are within acceptable limits, install the corresponding thickness adjustment shims. The thickness interval of the process adjustment shims is generally 0.05mm or 0.1mm.

[0115] c) Check the meshing clearance by assembling the initially selected adjusting shims and obtain the initial measured value of the meshing clearance. Compare the initial meshing clearance with the required meshing clearance to obtain the difference in meshing clearance, and calculate the new adjusting shim thickness using an empirical formula.

[0116] d) Empirical formula for calculating the adjustment amount of the adjusting shim:

[0117] The change in the adjusting shim = (0.4 to 0.5) times the change in the meshing clearance.

[0118] Note: This formula is applicable to the meshing adjustment of spur bevel gear 1 with a normal pressure angle of 20° and a cone angle δ between 40° and 50°.

[0119] e) The meshing clearance can be adjusted by adjusting only one bevel gear 1's adjusting shim, or by adjusting both bevel gear 1's adjusting shims simultaneously. The method is as follows: "Increasing the thickness of the adjusting shims of both bevel gear 1 simultaneously" will decrease the meshing clearance; "decreasing the thickness of the adjusting shims of both bevel gear 1 simultaneously" will increase the meshing clearance; "increasing the thickness of one adjusting shim while decreasing the thickness of the other adjusting shim" will keep the meshing clearance unchanged.

[0120] f) After the meshing clearance is adjusted to be within acceptable limits, adjust the coloring marks. To ensure that the meshing clearance remains unchanged, adjust the coloring marks by "increasing the thickness of one adjusting shim while decreasing the thickness of another adjusting shim".

[0121] g) Methods for adjusting the position of the coloring mark: Increasing the thickness of the moving gear adjustment shim will cause the moving gear tooth surface to move closer to the tooth tip along the tooth height direction, and the mating gear tooth surface to move closer to the tooth root along the tooth height direction; Decreasing the thickness of the moving gear adjustment shim will cause the moving gear tooth surface to move closer to the tooth root along the tooth height direction, and the mating gear tooth surface to move closer to the tooth tip along the tooth height direction.

[0122] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for assembling and adjusting a bevel gear pair for an aircraft engine, wherein the bevel gear pair comprises two bevel gears meshing with a shaft angle of 90°; Both the meshing clearance adjusting shim and the axial clearance adjusting shim act on the coaxial bearing on which the bevel gears are mounted, and are used to adjust the meshing clearance and axial clearance between the two bevel gears, respectively; characterized in that, The assembly and adjustment method for the bevel gear pair includes the following steps: S101: Initially select and match the axial clearance adjusting shim and the meshing clearance adjusting shim, install the two bevel gears and form the bevel gear pair; wherein, the thickness of the axial clearance adjusting shim is initially selected based on the following formula: N2 = H2 - (B + C2) - D In the formula: N2—Theoretical calculated thickness of the axial clearance adjusting shim; H2—Depth dimension of the bearing collar; C2—Dimension of the protruding edge of the limiting mounting edge; B—Inner ring width dimension of the coaxial bearing; D—The theoretical axial clearance of the bevel gear; Meanwhile, the thickness of the meshing clearance adjusting shim is selected based on the following formula: N1= E - (А+В+ N2 +С1 + D1) + L In the formula: E - The distance between the mating surface of the bevel gear mounting housing and the centerline of the bevel gear mounting hole; A - The distance from the support end face of the bevel gear to the top of the gear cone; B - Inner ring width dimension of the coaxial gear bearing; N1 - Thickness of the meshing clearance adjustment shim; C1 - Dimensions of the protruding part of the limiting mounting edge; D1 - The dimension of the protruding edge from the housing mating surface to the limiting mounting edge; L - Half of the axial clearance of the coaxial bearing; Theoretical calculated thickness of N2-axial clearance adjustment shim; S102: Measure the meshing clearance of the bevel gear pair under a preset axial load; apply a colorant to both sides of all teeth of the driving gear of the bevel gear pair; Under a preset axial load and in the braking state of the driven bevel gear, the driving bevel gear in the bevel gear pair is rotated, and the coloring state of the bevel gear pair is obtained based on the adhesion state of the colorant on the two tooth surfaces of the driven bevel gear of the bevel gear pair. S103: If the meshing gap does not meet the requirements, the thickness of the meshing gap adjusting shim is changed. The thickness adjustment range of the meshing gap adjusting shim is equal to 0.4-0.5 times the meshing gap to be adjusted. If the coloring state does not meet the requirements after the meshing gap meets the requirements, the thickness of the meshing gap adjusting shim is adjusted again. The thickness adjustment range of the meshing gap adjusting shim is equal to 10 times the change in the imprint C value to be adjusted. The meshing clearance adjusting shim is disposed on the side of the coaxial bearing near the teeth of the bevel gear; the meshing clearance adjusting shim simultaneously contacts the bevel gear and the coaxial bearing; The axial clearance adjusting shim is disposed on the side of the coaxial bearing away from the teeth of the bevel gear; the meshing clearance adjusting shim simultaneously contacts the coaxial bearing and the limiting mounting edge of the coaxial bearing.

2. The method for assembling and adjusting a bevel gear pair in an aero-engine according to claim 1, characterized in that, When adjusting the coloring state, if the thickness of one meshing gap adjustment shim is increased, the thickness of the other meshing gap adjustment shim is decreased by the same amount. When adjusting the coloring state, if the thickness of one meshing gap adjustment shim is reduced, the thickness of the other meshing gap adjustment shim is increased by the same amount.

3. The method for assembling and adjusting a bevel gear pair in an aero-engine according to claim 1, characterized in that, The normal pressure angle between a pair of bevel gears is 18~22°, and the cone angle between a pair of bevel gears is 40°~50°.

4. The method for assembling and adjusting a bevel gear pair in an aero-engine according to claim 1, characterized in that, The colorant is orange-red red lead powder.

5. The method for assembling and adjusting a bevel gear pair for an aero-engine according to claim 4, characterized in that, The colorant comprises industrial lead tetroxide and 8B lubricating oil in a weight ratio of 1:

1.

6. The method for assembling and adjusting a bevel gear pair for an aero-engine according to claim 1, characterized in that, The preset axial load is used to remove the axial clearance of the bearing between the two bevel gears.

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