Graphite Seal Processing Equipment and Processing Method

Abstract

This invention belongs to the field of parts processing technology, and relates to a graphite seal processing device and method. It includes a first clamping body, a sealing assembly, and a second clamping body placed coaxially in sequence. The first and second clamping bodies are respectively fitted onto the two outer end faces of the sealing assembly, and are engaged. The sealing assembly includes a first seal, a bushing, and a second seal. The first and second seals are coaxial and connected sequentially. The bushing is fitted over the outside of the connection between the first and second seals, and the structures of the first and second seals are mirror images of each other. The first clamping body is fitted onto the outer end face of the first seal, and the second clamping body is fitted onto the outer end face of the second seal. Both the first and second seals contain parts to be processed. This invention provides a graphite seal processing device and method that can effectively reduce part deformation, improve processing efficiency, and produce high-quality parts.

Description

Technical Field

[0001] This invention belongs to the field of parts processing technology, and relates to a graphite seal processing device and processing method. Background Technology

[0002] Graphite seals are crucial components for sealing the main shaft of aero engines. They are contact seals and represent one of the most advanced sealing methods currently available for aero engines. A graphite seal consists of a graphite ring and a housing. The end face of the graphite sealing ring and the end face of the sealing seat form a sealing pair, jointly achieving an axial static seal. The inner bore of the graphite sealing ring and the engine main shaft form a sealing pair, jointly achieving a radial dynamic seal.

[0003] However, as graphite is a typical brittle material, its machining process is difficult. The impact of the cutting tool on the graphite causes edge chipping and corner breakage. Moreover, the machined surface is a rough and uneven three-dimensional fractured surface with irregularly distributed surface defects and pits of varying sizes. This results in a low yield rate and long processing cycle for graphite parts, which is both time-consuming and labor-intensive. The machining cost of graphite seals is also high, which limits the application and promotion of graphite materials.

[0004] The existing graphite seal consists of two thin-walled annular parts (graphite ring and shell). One part is made of graphite, a difficult-to-machine material, and the other is a thin-walled, easily deformable shell. The required surface roughness of the machined inner hole is Ra0.4, the dimensional accuracy is 0.05mm, and the perpendicularity is 0.038mm. The main processing flow is: bonding – turning the outer diameter and inner hole – grinding the inner hole – sealing test. The key process is grinding the inner hole (small dimensional tolerance, high surface roughness, and strict perpendicularity requirements); however, in the entire processing flow, grinding the inner hole is the critical point for ensuring the performance characteristics (small dimensional tolerance, high surface roughness, and strict perpendicularity). Because this graphite seal is a thin-walled part, hand-held grinders are prone to damaging the part during grinding, causing edge chipping and corner breakage of the graphite, resulting in low yield and low efficiency. In addition, grinding is a manual operation, and perpendicularity is extremely easy to exceed tolerance, seriously affecting the sealing performance of the graphite seal and resulting in poor processing quality. Summary of the Invention

[0005] To address the technical problems of low yield and poor quality in existing graphite seal processing, this invention provides a graphite seal processing device and method that can effectively reduce part deformation, improve processing efficiency, and produce high-quality parts.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A graphite seal processing device includes a first clamping body, a sealing assembly, and a second clamping body arranged coaxially in sequence; the first clamping body and the second clamping body are respectively fitted onto the two outer end faces of the sealing assembly, the first clamping body and the second clamping body are engaged, and the sealing assembly contains a workpiece to be processed.

[0008] The sealing assembly includes a first seal, a bushing, and a second seal; the first and second seals are coaxial and connected in sequence, the bushing is fitted onto the outside of the connection between the first and second seals, and the structures of the first and second seals are mirror images of each other; the first clamp is fitted onto the outer end face of the first seal, and the second clamp is fitted onto the outer end face of the second seal; both the first and second seals contain a workpiece to be processed.

[0009] The first sealing element includes a first housing, which is fitted over the outside of a first graphite ring to be processed, and the first graphite ring to be processed and the first housing are coaxially arranged; the second sealing element includes a second housing, which is fitted over the outside of a second graphite ring to be processed, and the second graphite ring to be processed and the second housing are coaxially arranged; the first housing and the second housing are coaxial and connected in sequence, and the bushing is fitted at the connection between the first housing and the second housing; the first clamping body is fitted on the outer end face of the first housing, and the second clamping body is fitted on the outer end face of the second housing.

[0010] Furthermore, both the first clamping body and the second clamping body are hollow cylinders on the outside and hollow inside. Both the first clamping body and the second clamping body have stepped surfaces inside, and the interiors of the first clamping body and the second clamping body are interlocked.

[0011] A processing method based on the aforementioned graphite seal processing apparatus includes the following steps:

[0012] 1) The sealing assembly is clamped in the first clamping body and the second clamping body, with the two outer end faces of the sealing assembly corresponding to the inner hole step surface of the first clamping body and the inner hole step surface of the second clamping body, and flush and tightly attached.

[0013] 2) Grind the inner hole of the workpiece to be processed in the sealing assembly clamped in step 1).

[0014] Furthermore, the clamping process in step 1) is as follows: the right end face of the first seal and the left end face of the second seal are respectively placed against the left end face of the bushing and the right end face of the bushing to form a sealing assembly; then the first seal, the bushing and the second seal are installed into the first clamping body and the second clamping body, and the first clamping body is fastened to the second clamping body by threads.

[0015] Furthermore, in step 2), the inner hole of the first clamping body and the inner hole of the second clamping body are slightly larger than the inner hole size on the first graphite ring.

[0016] The beneficial effects of this invention are:

[0017] 1. The processing device provided by the present invention is highly operable, can ensure the perpendicularity of the parts, and has good sealing performance; the processing quality is good; in addition, when grinding the inner hole on the graphite ring, the inner hole of the first clamping body and the second clamping body can protect the sealing assembly, effectively avoid the deformation of the graphite ring during grinding, the parts are not easily damaged by clamping, and the edge chipping and corner breaking of the graphite can be avoided, thus improving the processing efficiency.

[0018] 2. The sealing assembly provided by the present invention includes a first seal, a bushing and a second seal. The number of parts processed at one time is two, and the processing efficiency is increased from the original 45% to 96%, which is a significant improvement in efficiency. Attached Figure Description

[0019] Figure 1 This is an exploded view of the processing apparatus provided by the present invention;

[0020] Figure 2 This is an exploded view of the assembly of the first and second seals.

[0021] Figure 3 This is an assembly diagram of the first and second sealing elements of the present invention;

[0022] in:

[0023] 1—First clamping body; 2—First sealing element; 21—First housing; 22—First graphite ring; 3—Bushing; 4—Second sealing element; 41—Second housing; 42—Second graphite ring; 5—Second clamping body. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] See Figures 1-3 A graphite seal processing device includes a first clamp 1, a sealing assembly, and a second clamp 5 placed coaxially in sequence; the first clamp 1 and the second clamp 5 are respectively fitted onto the two outer end faces of the sealing assembly, the first clamp 1 and the second clamp 5 are engaged, and the sealing assembly contains the workpiece to be processed.

[0026] The sealing assembly includes a first seal 2, a bushing 3, and a second seal 4; the first seal 2 and the second seal 4 are coaxial and connected sequentially, the bushing 3 is fitted over the outside of the connection between the first seal 2 and the second seal 4, and the structures of the first seal 2 and the second seal 4 are mirror images of each other; a first clamping body 1 is fitted over the outer end face of the first seal 2, and a second clamping body 5 is fitted over the outer end face of the second seal 4. Both the first seal 2 and the second seal 4 contain a workpiece to be processed.

[0027] The first seal 2 and the second seal 4 are placed back to back, and the bushing 3 is placed between the first seal 2 and the second seal 4, that is, the right end face of the first seal 2 rests on the left end face of the bushing 3, and the left end face of the second seal 4 rests on the right end face of the bushing 3. The first seal 2, the bushing 3 and the second seal 4 form a sealing assembly.

[0028] The first sealing element 2 includes a first housing 21, which is fitted over the outside of the first graphite ring 22 to be processed, and the first graphite ring 22 to be processed and the first housing 21 are coaxially arranged; the second sealing element 4 includes a second housing 41, which is fitted over the outside of the second graphite ring 42 to be processed, and the second graphite ring 42 to be processed and the second housing 41 are coaxially arranged; the first housing 21 and the second housing 41 are coaxial and connected in sequence, and the bushing 3 is fitted at the connection between the first housing 21 and the second housing 41; the first clamping body 1 is fitted on the outer end face of the first housing 21, and the second clamping body 5 is fitted on the outer end face of the second housing 41.

[0029] Both the first clamping body 1 and the second clamping body 5 are hollow cylinders. Both the first clamping body 1 and the second clamping body 5 have stepped surfaces inside, and the interiors of the first clamping body 1 and the second clamping body 5 are interlocked.

[0030] A processing method for a graphite seal processing device includes the following steps:

[0031] 1) The sealing assembly is clamped in the first clamping body 1 and the second clamping body 5, with the two outer end faces of the sealing assembly corresponding to the inner hole step surface of the first clamping body 1 and the inner hole step surface of the second clamping body 5, and flush and tightly attached.

[0032] 2) Grind the inner hole of the workpiece to be processed in the sealing assembly clamped in step 1).

[0033] The clamping process in step 1) is as follows: the right end face of the first sealing element 2 and the left end face of the second sealing element 4 are respectively placed against the left end face and the right end face of the bushing 3 to form a sealing assembly; then the first sealing element 2, the bushing 3 and the second sealing element 4 are installed into the first clamping body 1 and the second clamping body 5, and the first clamping body 1 is fastened to the second clamping body 5 by threads.

[0034] In step 2), the inner hole of the first clamping body 1 and the inner hole of the second clamping body 5 are slightly larger than the inner hole size of the first graphite ring 22 to be processed.

[0035] The present invention proposes a graphite sealing component processing device with the following clamping process: two graphite sealing ring parts are respectively placed against the two end faces of the bushing 3 for positioning, and the inner hole reference of the graphite sealing component is transformed to the outer circle of the shell. The outer circle of the shell and the end face of the bushing 3 are then converted to be mutually referenced, i.e., the perpendicularity of the outer circle of the shell to the end face of the bushing 3. The two fixed graphite sealing components and the bushing are then installed together into the first clamping body 1 and the second clamping body 5 (the other two end faces of the two graphite sealing components are flush and close to the bottom surface of the inner hole step of the first clamping body 1 and the second clamping body 5, respectively). The first clamping body 1 and the second clamping body 5 are then fastened by internal and external threads to fix the two graphite sealing components in the entire clamping body. The inner hole of the component (graphite ring) is then ground (the inner hole of the clamping body is similar in size to the inner hole of the component, leaving a grinding allowance for the component).

[0036] After testing and verification on multiple batches of parts on site, the use of this special grinding fixture not only ensures the surface roughness of the parts but also avoids the problem of excessive perpendicularity. The processing efficiency has been increased from 45% to 96%, showing a significant improvement in efficiency.

[0037] In order to better promote and apply this invention, the following specific measures are taken for different incoming materials:

[0038] (1) For parts with the same outer diameter but different lengths, design and manufacture inner and outer clamping bodies with different thread matching depths or adjust the length of the bushing, install them in the clamping body, and process similar structural parts.

[0039] (2) For parts with different outer diameters, when the outer diameter of the part is larger than the inner diameter of the device, redesign the inner and outer clamping bodies and bushings; when the outer diameter of the part is smaller than the inner diameter of the device, design a corresponding outer diameter adjustment bushing, install it into the inner diameter of the device, and continue the above operations.

[0040] (3) For different inner hole sizes of parts, when the inner hole size of the part is larger than the inner hole size of the device, redesign the inner and outer clamping bodies; when the inner hole size of the part is smaller than the inner hole size of the device, ensure that the clamping is aligned and continue the above operation.

Claims

1. A graphite seal processing apparatus, characterized in that, It includes a first clamping body (1), a sealing assembly, and a second clamping body (5) placed coaxially in sequence; the first clamping body (1) and the second clamping body (5) are respectively fitted onto the two outer end faces of the sealing assembly, the first clamping body (1) and the second clamping body (5) are snapped together, and the sealing assembly contains a workpiece to be processed; The first clamping body (1) and the second clamping body (5) are both hollow cylinders. The first clamping body (1) and the second clamping body (5) are both provided with stepped surfaces. The first clamping body (1) and the second clamping body (5) are interlocked. The sealing assembly includes a first seal (2), a bushing (3), and a second seal (4); the first seal (2) and the second seal (4) are coaxial and connected in sequence, the bushing (3) is fitted onto the outside of the connection between the first seal (2) and the second seal (4), and the structures of the first seal (2) and the second seal (4) are mirror images of each other; the first clamping body (1) is fitted onto the outer end face of the first seal (2), and the second clamping body (5) is fitted onto the outer end face of the second seal (4); both the first seal (2) and the second seal (4) contain a workpiece to be processed. The first sealing element (2) includes a first housing (21), which is fitted around the first graphite ring (22) to be processed, and the first graphite ring (22) to be processed and the first housing (21) are coaxially arranged; the second sealing element (4) includes a second housing (41), which is fitted around the second graphite ring (42) to be processed, and the second graphite ring (42) to be processed and the second housing (41) are coaxially arranged; the first housing (21) and the second housing (41) are coaxial and connected in sequence, and the bushing (3) is fitted at the connection between the first housing (21) and the second housing (41); the first clamping body (1) is fitted on the outer end face of the first housing (21), and the second clamping body (5) is fitted on the outer end face of the second housing (41).

2. A processing method based on the graphite seal processing apparatus of claim 1, characterized in that, The processing method includes the following steps: 1) The sealing assembly is clamped in the first clamping body (1) and the second clamping body (5), with the two outer end faces of the sealing assembly flush and tightly against the inner hole step surface of the first clamping body (1) and the inner hole step surface of the second clamping body (5). 2) Grind the inner hole of the workpiece to be processed in the sealing assembly clamped in step 1).

3. The processing method according to claim 2, characterized in that, The clamping process in step 1) is as follows: the right end face of the first sealing element (2) and the left end face of the second sealing element (4) are respectively placed against the left end face and the right end face of the bushing (3) to form a sealing assembly; then the first sealing element (2), the bushing (3) and the second sealing element (4) are installed into the first clamping body (1) and the second clamping body (5), and the first clamping body (1) is fastened to the second clamping body (5) by threads.

4. The processing method according to claim 3, characterized in that, In step 2), the inner hole of the first clamping body (1) and the inner hole of the second clamping body (5) are both slightly larger than the inner hole size on the first graphite ring (22) to be processed.

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