A small clearance bolt assembly method

Abstract

A small gap bolt assembly method, comprising: pre-setting three process positioning pins with three different structures; after pre-treating the bolt head, using the first process positioning pin to uniformly correct the concentricity of the sealing disc and the turbine disc bolt connection hole; using the second process positioning pin to uniformly correct the concentricity of the drum shaft, the sealing disc and the turbine disc connection hole; using the third process positioning pin to inspect the bolt hole system after assembly; after inspection, installing the formal bolt in the position except the process bolt, disassembling the process bolt and replacing the formal bolt. According to the method, the small gap bolt of a certain type of high-pressure turbine rotor balance assembly is assembled, and no deep spiral line is found on the bolt rod after disassembly, and the surface quality is good, effectively solving the problems of assembly quality and efficiency of small gap bolts.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical assembly, in particular to a small gap bolt assembly method. BACKGROUND

[0002] The high pressure turbine rotor assembly of an aero-engine is assembled by turbine disc, sealing disc, drum shaft and other parts, and is connected by bolts and nuts. Generally, the gap between the bolt rod and the diameter of the part connecting hole is about 0.5mm, but after using small gap bolts, the radial theoretical gap between the bolt rod and the part connecting hole is only 0.1mm. Since the bolts need to pass through three part connecting holes to connect each part together, due to the inevitable position difference of each part connecting hole, the theoretical gap between the bolt and the part connecting hole is only 0.02mm. The conventional visual assembly method cannot guarantee that the bolt is completely aligned with the assembly hole, and the interference between the bolt and the hole wall will cause the rod to be squeezed and produce obvious depth spiral lines, which cannot guarantee the surface quality requirements. SUMMARY

[0003] The purpose of the present application is to provide a small gap bolt assembly method to solve the problem that the conventional visual assembly method cannot guarantee that the bolt is completely aligned with the assembly hole, and the interference between the bolt and the hole wall will cause the rod to be squeezed and produce obvious depth spiral lines, which cannot guarantee the surface quality requirements.

[0004] To achieve the above purpose, the present application adopts the following technical scheme:

[0005] A small gap bolt assembly method, comprising:

[0006] Pre-setting three process positioning pins with three different structures;

[0007] After pretreating the bolt head, using the first process positioning pin to uniformly correct the concentricity of the sealing disc and the turbine disc bolt connecting hole;

[0008] Using the second process positioning pin to uniformly correct the concentricity of the drum shaft, sealing disc and turbine disc connecting hole;

[0009] Using the third process positioning pin to check the bolt hole system after assembly;

[0010] After checking, installing the formal bolt in the position except the process bolt, disassembling the process bolt and replacing the formal bolt.

[0011] Further, pre-setting three process positioning pins with three different structures:

[0012] During assembly, three positioning pins are used for positioning, numbered in the first, second and third order, and process bolts are used to correct the plate nuts of part of the holes.

[0013] Further, the bolt head is pretreated:

[0014] Mark the sequence number on the bolt head with a marker pen and apply lubricating grease on the threaded part before assembly.

[0015] Further, use the first type of positioning pin to uniformly correct the concentricity of the bolt connection holes of the sealing disc and the turbine disc:

[0016] Install the sealing disc on the turbine disc assembly, uniformly install 8 first type of positioning pins, tighten the positioning pins with a wrench, uniformly correct the concentricity of the bolt connection holes of the sealing disc and the turbine disc, then uniformly install 8 process bolts, limit the axial tightness of the parts, and then disassemble the process bolts and the first type of positioning pins.

[0017] Further, use the second type of positioning pin to uniformly correct the concentricity of the drum shaft, sealing disc, and turbine disc connection holes:

[0018] Install the sealing disc on the drum assembly, uniformly install 8 second type of positioning pins, make the rod part of the positioning pin fit with the inner wall of the drum shaft, sealing disc bolt hole, uniformly correct the concentricity of the drum shaft, sealing disc, and turbine disc connection holes, uniformly tighten 8 process bolts symmetrically, and limit the axial tightness of the parts.

[0019] Further, use the third type of process positioning pin to inspect the assembled bolt hole system:

[0020] Use the third type of process positioning pin to inspect the assembled bolt hole system to ensure the accurate position of the turbine disc, sealing disc, and drum shaft assembly holes, and then disassemble the second and third type of positioning pins.

[0021] Further, after checking, install the formal bolts except for the process bolt positions:

[0022] Install the formal bolts except for the 8 process bolt positions, manually tighten to self-locking, and measure the height of the bolt head to the drum shaft end surface to meet the preset requirements to ensure no interference;

[0023] Further, tighten the bolts until the bolt head fits with the drum shaft end surface, then unscrew the bolts, check the bolt rod part for spiral line marks, and replace the bolts that do not meet the requirements and reassemble according to the above steps.

[0024] Further, the preset requirement is 16mm.

[0025] Further, disassemble the process bolts and replace them with formal bolts:

[0026] Disassemble the 8 process bolts, replace them with formal bolts, uniformly limit all bolts to 2 / 3 torque requirement, and then uniformly limit them to torque requirement.

[0027] Compared with the prior art, the present application has the following technical effects:

[0028] The present application can reduce the interference between the bolt and the connecting hole, avoid the damage of the bolt, and improve the one-time assembly qualification rate of the assembly. It has strong adaptability and on-site promotion value.

[0029] According to the method, the small-gap bolt of the balance assembly of a certain type of high-pressure turbine rotor is assembled, and no deep spiral line is found on the bolt rod part after disassembly, and the surface quality is good, effectively solving the assembly quality and efficiency problem of the small-gap bolt. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a flowchart.

[0031] Figure 2 is a schematic view of the first pin correcting the hole position of the high-pressure turbine disc and the turbine front sealing disc.

[0032] Figure 3 is a schematic view of the second pin correcting the hole position of the drum shaft and the sealing disc

[0033] Figure 4 is a schematic view of the third pin checking the installation position of the turbine rotor hole. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0035] In the description of the present application, it should be understood that the terms "include" and "contain" indicate the existence of described features, whole, steps, operations, elements and / or components, but do not exclude the existence or addition of one or more other features, whole, steps, operations, elements, components and / or sets thereof.

[0036] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, unless otherwise clear from the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0037] It should be further understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items, and that the term "or" as used herein refers to and encompasses any one of the associated items, but not necessarily including all possible combinations of the associated items. It should also be further understood that the term "comprising" as used herein is used in the inclusive sense of "including" and / or "comprising" and not by way of limitation. The term "consisting essentially of as used herein is used in the inclusive sense of "consisting essentially of, and not by way of limitation. The term "consisting of as used herein is used in the limiting sense of "consisting of, and not by way of limitation. It should also be further understood that the term "coupled" as used herein refers to any connection, coupling, or attachment between two or more elements, and that the term "couples" or "coupling" as used herein refers to any connection, coupling, or attachment between two or more elements. It should also be further understood that the term "if can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting" depending on the context. Similarly, the phrase "if it is determined" or "if (a stated condition or event) is detected" can be interpreted to mean "when it is determined" or "in response to determining" or "when (the stated condition or event) is detected" or "in response to detecting (the stated condition or event)", depending on the context.

[0038] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various ranges or elements, these ranges or elements should not be limited by these terms. These terms are only used to distinguish one range or element from another. For example, a first range could be termed a second range without departing from the scope of the embodiments.

[0039] The word "if as used herein can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if (a stated condition or event) is detected" can be interpreted to mean "when it is determined" or "in response to determining" or "when (the stated condition or event) is detected" or "in response to detecting (the stated condition or event)", depending on the context.

[0040] Various structural diagrams according to the disclosed embodiments of the present application are shown in the accompanying drawings. These diagrams are not drawn to scale, in which certain details are shown in a somewhat exaggerated manner for the purpose of clarity and understanding, and certain details can be omitted. The shapes of various regions, layers, and the relative size and positional relationship between them shown in the drawings are only exemplary, and in actuality, they can deviate due to manufacturing tolerances or technical limitations, and a person skilled in the art can additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0041] The present application provides a small gap bolt assembly method, comprising:

[0042] Three process positioning pins with three different structures are preset;

[0043] After the bolt head is pretreated, the first process positioning pin is used to uniformly correct the concentricity of the bolt connection hole of the sealing disc and the turbine disc;

[0044] The second process positioning pin is used to uniformly correct the concentricity of the connection hole of the drum shaft, the sealing disc, and the turbine disc;

[0045] The third process positioning pin is used to inspect the bolt hole system after assembly;

[0046] After verifying that everything is correct, install the standard bolts in the positions where the process bolts were removed, disassemble the process bolts, and replace them with standard bolts.

[0047] The specific assembly process is as follows:

[0048] 1) Before assembly, mark the sequence number on the bolt head with a marker and apply grease to the threaded part.

[0049] 2) Install the sealing disc onto the turbine disk assembly, evenly insert eight first-type tapered locating pins, tighten the locating pins with a wrench, and evenly align the concentricity of the bolt connection holes between the sealing disc and the turbine disk. Figure 2 As shown. Then, eight process bolts are evenly distributed and installed to limit the force and ensure that the parts are axially tight. Then, the process bolts and the first type of locating pin are disassembled.

[0050] Figure 2 Schematic diagram of the first type of pin-aligned high-pressure turbine disk and turbine front sealing disk hole position.

[0051] 3) Install the drum assembly into the sealing disc stop, and evenly distribute eight second-process locating pins to ensure the pin rods fit against the drum shaft and the inner wall of the sealing disc bolt holes. Evenly distribute and correct the concentricity of the connecting holes of the drum shaft, sealing disc, and turbine disc (e.g., ...). Figure 3 (As shown). Eight process bolts are evenly distributed and symmetrically tightened to limit the force and ensure that the parts are axially close together.

[0052] 4) Use a third type of pin to inspect the assembled bolt hole system, such as... Figure 4 As shown, ensure the turbine disc, sealing disc, and drum shaft assembly hole positions are accurate, and then disassemble the second and third types of locating pins.

[0053] 5) Install the official bolts (except for the 8 process bolt positions), manually tighten them until they are self-locking, and measure the height from the bolt head to the end face of the drum shaft to ensure that it meets the requirement of 16mm and there is no interference.

[0054] 6) Tighten the bolts until the bolt heads are flush with the end face of the drum shaft. Then unscrew the bolts and check the bolt shanks for any spiral marks. Replace any bolts that do not meet the requirements and reassemble according to the steps above.

[0055] 7) Disassemble the 8 process bolts and replace them with the standard bolts according to steps 5) and 6).

[0056] 8) Limit the force on all bolts symmetrically and evenly to 2 / 3 of the required torque, and then limit the force on all bolts symmetrically and evenly to the required torque.

[0057] This embodiment, through the methods described above, including designing dedicated locating pins, defining assembly steps, and controlling assembly torque, can reduce interference between bolts and connecting holes, avoid bolt damage, and improve the first-time assembly pass rate of components. It has strong adaptability and field application value.

[0058] This method was used to assemble the small-gap bolts of a certain type of high-pressure turbine rotor balancing assembly. After disassembly, the bolt shank was inspected and no deep helical lines were found. The surface quality was good, which effectively solved the assembly quality and efficiency problems of small-gap bolts.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for assembling small-gap bolts, characterized in that, include: Three different structural and process positioning pins are pre-set; After pre-treating the bolt heads, the first process is used to evenly distribute locating pins to correct the concentricity of the bolt connection holes between the sealing disc and the turbine disc; The second process uses evenly distributed positioning pins to correct the concentricity of the connecting holes of the drum shaft, sealing disc, and turbine disc. The third process locating pin is used to inspect the assembled bolt hole system; After verifying that everything is correct, install the standard bolts in the positions where the process bolts were removed, disassemble the process bolts, and replace them with standard bolts. The first process uses evenly distributed locating pins to correct the concentricity of the bolt connection holes between the sealing disc and the turbine disc: Install the sealing disc onto the turbine disk assembly, evenly insert 8 first-type process locating pins, tighten the locating pins with a wrench, evenly correct the concentricity of the bolt connection holes between the sealing disc and the turbine disk, then evenly insert 8 process bolts, limit the force to ensure the parts are axially tight, and then disassemble the process bolts and the first-type locating pins. The second process uses evenly distributed positioning pins to correct the concentricity of the connecting holes of the drum shaft, sealing disc, and turbine disc: The drum assembly is inserted into the sealing disc stop, and eight second-process positioning pins are evenly installed to make the pin rods fit against the inner walls of the drum shaft and sealing disc bolt holes. The concentricity of the connecting holes of the drum shaft, sealing disc and turbine disc is evenly corrected, and eight process bolts are evenly tightened symmetrically to limit the force and ensure that the parts are axially tight. Use the third process locating pin to inspect the assembled bolt hole system: Use the third type of locating pin to inspect the assembled bolt hole system to ensure that the assembly holes of the turbine disc, sealing disc, and drum shaft are in accurate position. Then disassemble the second and third types of locating pins. After verifying that everything is correct, install the standard bolts in the positions excluding the process bolts: In addition to installing the permanent bolts at the eight process bolt positions, manually tighten them until they are self-locking, and measure the height from the bolt head to the end face of the drum shaft to ensure that it meets the preset requirements and that there is no interference.

2. The method for assembling small-gap bolts according to claim 1, characterized in that, Three different types of locating pins with different structures are pre-set: Three types of locating pins are used for positioning during the assembly process, and they are numbered as the first, second and third types. Process bolts are used to correct the support plate nuts of some holes.

3. The method for assembling small-gap bolts according to claim 1, characterized in that, Pre-treatment of bolt heads: Before assembly, mark the sequence number on the bolt head with a marker and apply grease to the threaded part.

4. The method for assembling small-gap bolts according to claim 1, characterized in that, Tighten the bolts until the bolt head fits against the end face of the drum shaft. Then unscrew the bolts and check for any spiral marks on the bolt shank. Replace any bolts that do not meet the requirements and reassemble the machine according to the steps described above.

5. The method for assembling small-gap bolts according to claim 1, characterized in that, The preset requirement is 16mm.

6. The method for assembling small-gap bolts according to claim 1, characterized in that, Disassemble the process bolts and replace them with the standard bolts: Disassemble the 8 process bolts, replace them with the standard bolts, symmetrically and evenly limit the force on all bolts to 2 / 3 of the torque requirement, and then symmetrically and evenly limit the force on all bolts to the torque requirement.

Images