High temperature high pressure fluid rotary seal joint

Abstract

The utility model discloses a high temperature high pressure fluid rotary seal joint. The joint includes outer tube, rotary inner tube, two rows of zirconium oxide ceramic bearing, the rotary gley ring seal assembly and the compression ring made of PI / FFKM material. The ceramic bearing effectively solves the rotary jam problem under high temperature; the double gley ring sealing lip design has the fluid power groove, and the friction and abrasion are reduced significantly while realizing the high pressure sealing; all metal parts adopt 06Cr19Ni10 stainless steel, and the corrosion resistance is ensured. The utility model solves the sealing failure, jam and abrasion problem of the prior art under 300 DEG C, 5MPa aviation kerosene medium environment through material innovation and structure optimization, and is especially suitable for the fluid transmission system of high-end equipment such as aerospace engine, and has high reliability and long life.

Description

Technical Field

[0001] This utility model relates to the field of mechanical sealing and precision manufacturing technology, specifically a high-temperature and high-pressure fluid rotary sealing joint. Background Technology

[0002] Rotary sealing joints are core components connecting stationary pipelines and rotating parts, and their performance directly determines the sealing performance, reliability, and service life of the fluid transmission system. In high-end equipment such as aero-engines, rotary joints must simultaneously meet three stringent requirements: withstand temperatures of 300℃, withstand pressures of 5MPa, and be compatible with aviation kerosene media. Existing technologies have significant shortcomings: High risk of seal failure: Conventional fluororubber seals are prone to aging and hardening at 300℃, losing elasticity and failing to maintain sealing performance; high pressure environment further aggravates wear and extrusion deformation of the sealing lip, leading to aviation kerosene leakage and affecting system safety.

[0003] High-temperature rotational jamming: Traditional metal bearings and bushings have a large difference in thermal expansion coefficients (the thermal expansion coefficient of metal is approximately 12 × 10⁻). 6 / ℃), the clearance disappears under high temperature thermal cycling, causing seizure and jamming, making it impossible to guarantee the design rotation speed of 100r / min and affecting the normal operation of the equipment.

[0004] Short wear life: Under the superposition of high speed rotation and high pressure, the friction between the seal and the rotating shaft is intensified, and the traditional sealing structure has no lubrication optimization design, resulting in a fast wear rate and difficulty in meeting the requirements of long-term operation.

[0005] Poor manufacturing process adaptability: Existing processing is not optimized for high temperature and high pressure conditions, and the accuracy of key sealing surface roughness (needs to reach 0.4μm-1.6μm) and internal flow channel size (4mm) is difficult to guarantee. In addition, there are no standardized specifications for the assembly process, resulting in poor consistency during mass production.

[0006] Therefore, there is an urgent need to develop rotary sealing joints that combine high-temperature and high-pressure sealing, anti-jamming, and low-wear characteristics, as well as matching high-precision manufacturing processes, in order to solve the existing technical bottlenecks. Utility Model Content

[0007] This utility model provides a rotary sealing joint that, through material innovation and structural optimization, achieves stable transmission of aviation kerosene under high temperature of 300℃ and high pressure of 5MPa, solving the problems of sealing failure, rotation jamming, and severe wear.

[0008] The technical solution of this utility model: A high-temperature and high-pressure fluid rotary sealing joint includes an outer cylinder (1), a rotary inner tube (2), a ceramic bearing assembly (3), a sealing assembly, a clamping ring, and a limiting component. The structure and fit of each component are as follows: Core component structural design: Outer cylinder (1): Made of 06Cr19Ni10 stainless steel (chemical composition conforms to GB / T3280-2015, C≤0.07%, Cr17.5%-19.5%, Ni8%-10.5%), with a maximum outer diameter of φ20mm and a length of 28.5mm; a circular groove (11) is opened at one end, and the bottom of the groove is connected to the radial flow channel (12) at the other end through the axial flow channel (13). The inner flow channel size is 4mm (to meet the flow requirements of aviation kerosene transmission). A connecting pipe (14) is installed at the outer end of the radial flow channel (12) as a fluid outlet; an inner annular groove (111) is provided near the opening of the circular groove (11) (for bearing outer ring limit), and a first annular step (112) is provided at the bottom of the groove (for installing the main seal).

[0009] Rotating inner tube (2): made of 06Cr19Ni10 stainless steel, with an outer diameter of φ9.5mm and a length of 25mm, coaxially inserted into the circular groove (11) of the outer cylinder (1), and divided into a sealing section (21) and a bearing mounting section (22); the bearing mounting section (22) has an integrally formed annular mounting plate (221) at one end and an outer annular mounting groove (222) at the other end (used for bearing inner ring positioning), and the outer surface of the sealing section (21) needs to be polished to a roughness Ra≤0.4μm (to ensure sealing fit).

[0010] Ceramic bearing assembly (3): Uses two rows of zirconia full ball bearings (model 688CEF, size 8×16×4mm), with a high temperature range of 300℃-400℃, and has self-lubricating and anti-magnetic properties (thermal expansion coefficient of only 1.0×10⁻). 6 / ℃, to avoid high temperature jamming); the bearing is installed in the bearing mounting section (22) of the rotating inner tube (2). The inner ring of the outer bearing is axially limited by the annular clamp (221), and the inner ring of the inner bearing is limited by the hole clamp (61) in the outer annular clamp groove (222). The outer rings of the two rows of bearings are limited by the shaft clamp of the outer cylinder (1) installed in the inner annular clamp groove (111) to ensure that the rotational coaxiality is ≤0.02mm.

[0011] Sealing components: including a first sealing ring (41) and a second sealing ring (42), both of which are rotating Glyd rings for shafts (model 6×10.9×2.2mm); the inner sealing ring is made of PI (polyimide) material (long-term use at -260℃-330℃, heat distortion temperature 343℃), and the outer O-ring is made of perfluoroether rubber (FFKM, long-term operation at 300℃, compatible with aviation kerosene); the sealing lip of the Glyd ring is machined with a continuous fluid dynamic groove (groove width 0.2mm, depth 0.1mm), which can increase the unit sealing pressure and form a lubricating film to reduce friction and wear; the end face is provided with a pressure relief groove and the back is concave to prevent the sealing ring from rotating synchronously with the rotating inner tube (2) and optimize the pressure start-up performance.

[0012] Compression ring: Two ring-shaped components (06Cr19Ni10 stainless steel) are installed sequentially at the bottom of the circular groove (11) of the outer cylinder (1); a second annular step (511) is opened on the outside of the first compression ring (51) (for installing the second sealing ring 42), and a trapezoidal annular groove (521) is opened on the outside of the second compression ring (52) (to accommodate auxiliary sealing elements and form a multi-level sealing barrier). The roughness of the sealing surface of the compression ring must reach Ra≤1.6μm.

[0013] Limiting components: including hole clamp (61) and shaft clamp (62), both made of 06Cr19Ni10 stainless steel; hole clamp (61) conforms to GB / T893-2017 standard (specification φ16) and is used for limiting the inner ring of the inner ceramic bearing; shaft clamp (62) conforms to GB / T894-2017 standard (specification φ48) and is used for axial fixation of the rotating inner tube (2).

[0014] Working principle: Aviation kerosene flows in from one end of the rotating inner tube (2), enters the axial flow channel (13) of the outer cylinder (1) through its internal channel, and then flows out from the connecting pipe (14) through the radial flow channel (12); the double Douglas ring of the sealing assembly fits tightly with the sealing section (21) of the rotating inner tube (2) to form a high-pressure sealing barrier, and the hydrodynamic groove reduces friction and wear; the ceramic bearing assembly (3) ensures that the rotating inner tube (2) operates stably at 100r / min and avoids high-temperature jamming; the 06Cr19Ni10 material of the outer cylinder (1) and the rotating inner tube (2) ensures resistance to aviation kerosene corrosion, and the whole system achieves stable transmission under high temperature and high pressure. Beneficial effects

[0015] 1) Connector performance advantages: High temperature and high pressure adaptability: PI / FFKM Glyd rings and zirconia bearings can withstand high temperatures of 300℃ for a long time. Double seals + trapezoidal groove auxiliary seals can withstand high pressure of 5MPa. Aviation kerosene leakage is ≤0.01mL / min, meeting the stringent requirements of the aviation field.

[0016] Anti-jamming and low wear: Zirconia ceramic bearings have a low coefficient of thermal expansion, completely preventing high-temperature seizing; the Glyd ring hydrodynamic grooves reduce the coefficient of friction by 30%, and combined with optimization based on the Achard wear theory (wear coefficient K=0.18, material hardness H=50MPa), the wear volume per unit time is only 3.3264×10⁻ 6 m³ / s, with a service life more than twice that of traditional structures.

[0017] Corrosion resistance and compactness: 06Cr19Ni10 stainless steel is resistant to aviation kerosene corrosion and has a compact overall size (outer cylinder φ20mm×28.5mm), making it suitable for space-constrained scenarios in aviation equipment.

[0018] 2) Manufacturing process advantages: Controllable precision: The process is divided into roughing, semi-finishing and finishing stages, combined with diamond tools and grinding technology. The surface roughness of the key sealing surface reaches Ra0.4μm-1.6μm, and the dimensional tolerance reaches IT5-IT6, ensuring sealing and rotation performance.

[0019] High batch adaptability: Standardized processing using CNC equipment, pre-processing and assembly processes are replicable, single production can reach 200,000 pieces, with a pass rate of ≥98%, meeting the needs of industrial mass production.

[0020] Cost optimization: 06Cr19Ni10 material has a high cost performance, and the integrated processing reduces the number of parts. Assembly does not require special tools, which reduces manufacturing costs and the difficulty of later maintenance. Attached Figure Description

[0021] Figure 1 This is an axial cross-sectional view of the rotary sealing joint of this utility model.

[0022] Figure 2 This is a cross-sectional schematic diagram of the outer cylinder in this utility model.

[0023] Figure 3 This is a cross-sectional schematic diagram of the rotating inner tube of this utility model.

[0024] Figure 4 This is a cross-sectional schematic diagram of the rotating Glyph of this utility model.

[0025] Figure 5 This is a cross-sectional schematic diagram of the first clamping ring of this utility model.

[0026] Figure 6 This is a cross-sectional schematic diagram of the second clamping ring of this utility model.

[0027] Figure 7 This is a three-dimensional schematic diagram of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings. As shown in Figures 1 to 7, a high-temperature and high-pressure fluid rotary sealing joint includes an outer cylinder (1), a rotary inner tube (2), a ceramic bearing assembly (3), a sealing assembly, a clamping ring, and a limiting component. The outer cylinder (1) is made of stainless steel, with a circular groove (11) at one end and a radial flow channel (12) at the other end. The bottom of the circular groove (11) is connected to the radial flow channel (12) through an axial flow channel (13). The circular groove (11) has an inner annular groove (111) near the opening, and a first annular step (112) at the bottom of the circular groove (11). The rotary inner tube (2) is coaxially inserted into the circular groove (11) and includes a sealing section (21) and a bearing mounting section (22). One end of the bearing mounting section (22) has an annular retaining plate (221), and the other end has an outer annular groove (222). The ceramic bearing assembly (3) consists of two rows of zirconia full-ball bearings. The bearing is installed on the bearing mounting section (22). The outer bearing inner ring is limited by the annular retaining plate (221), and the inner bearing inner ring is limited by the retaining member in the outer annular retaining groove (222). The two rows of bearing outer rings are limited by the retaining member in the inner annular retaining groove (111). The sealing assembly includes a first sealing ring (41) and a second sealing ring (42), both of which are shaft rotating Glyd rings, composed of a PI inner ring sealing ring and an FFKMO type ring. The first sealing ring (41) is installed in the first annular step (112), and the second sealing ring (42) is installed on the clamping ring. The clamping ring consists of two stainless steel ring components, which are installed in the circular groove (11) in sequence. The retaining member includes a hole retainer (61) and a shaft retainer (62). The hole retainer is in the outer annular retaining groove (222), and the shaft retainer (62) is in the inner annular retaining groove (111). The bearing mounting end extends a certain length beyond the outer side of the annular clamp, and this length is used for subsequent connection and installation. A platform is also designed on both sides of the annular clamp to facilitate locking and rotating operations.

[0029] The outer cylinder (1) has a maximum outer diameter of φ20mm and a length of 28.5mm; the rotating inner tube (2) has an outer diameter of φ9.5mm and a length of 25mm, and the outer surface roughness of the sealing section (21) is ≤0.4μm; the outer cylinder (1) is made of 06Cr19Ni10 stainless steel; the inner flow channel size of the rotating inner tube is 4mm, and the zirconia full ball bearing model is 688CEF; the clamping ring is a 06Cr19Ni10 stainless steel ring component.

[0030] The rotating glyph has a continuous hydrodynamic groove on its sealing lip, a pressure relief groove on its end face, and a concave shape on its back. The clamping ring includes a first clamping ring (51) and a second clamping ring (52). The first clamping ring (51) has a second annular step (511) on its outer side. The second sealing ring (42) is installed in the second annular step (511). The second clamping ring (52) has a trapezoidal annular groove (521) on its outer side. The trapezoidal annular groove is designed to avoid components such as hole clips.

[0031] The manufacturing process technology solution for the above-mentioned rotary sealing joint includes the following steps: 1) Raw material preparation and testing: Purchase 06Cr19Ni10 stainless steel blanks (pipes / plates), zirconia full-ball bearings (model 688CEF), and PI / FFKM Glyd ring semi-finished products; the 06Cr19Ni10 stainless steel must conform to GB / T3280-2015 standard, with mechanical properties meeting the requirements of yield strength ≥205MPa and tensile strength ≥520MPa; the zirconia ceramic bearing hardness ≥1200HV, and the dimensional deviation of the Glyd ring semi-finished products ≤±0.05mm.

[0032] Raw material quality inspection: The element content of stainless steel is detected by a spectrometer to ensure that the composition is qualified; internal defects of stainless steel blanks are detected by ultrasonic testing (no cracks or inclusions); the rotational flexibility of bearings is tested (no jamming or abnormal noise).

[0033] 2) Machining of key components: Outer cylinder (1) processing: Rough machining: Fix the stainless steel plate to the CNC lathe fixture, use carbide tools to turn the outer circle (leave 0.3-0.5mm finishing allowance) and end face, drill the axial flow channel (13) and radial flow channel (12) (pre-drill φ3.5mm, leave 0.5mm allowance), and mill the round groove (11) (leave 0.2mm allowance for depth).

[0034] Semi-finishing: Change to high-speed steel tool, turn the outer circle to φ20.1mm, finish mill the circular groove (11) to the design depth, and drill and expand the flow channel to φ3.8mm; use CNC milling machine to process the inner annular groove (111) and the first annular step (112), and control the groove width tolerance within ±0.02mm.

[0035] Finishing: Use diamond tools to turn the outer circle to φ20mm (tolerance IT6), grind the inner wall of the flow channel to roughness Ra≤0.8μm; polish the inner wall of the circular groove (11) and the sealing surface of the first annular step (112) to ensure roughness Ra≤1.6μm; ultrasonic cleaning to remove chips and burrs.

[0036] Machining of the inner tube (2): Rough machining: After the stainless steel pipe is fixed, turn the outer diameter to φ9.8mm (leaving a 0.3mm allowance), cut the length to 25.3mm (leaving a 0.3mm allowance), and drill the inner hole (flow channel) to φ3.8mm.

[0037] Semi-finishing: Turn the outer circle to φ9.6mm, finish the length to 25.1mm, mill the transition surface between the sealing section (21) and the bearing mounting section (22), and machine the outer annular groove (222) (leaving a 0.05mm allowance for groove depth).

[0038] Finishing: The outer circle is ground to φ9.5mm (tolerance IT5), and the outer surface of the sealing section (21) is polished to a roughness Ra≤0.4μm; the outer annular groove (222) is precision milled to the design size and the cutting length is 25mm; after ultrasonic cleaning, it is dried.

[0039] Clamping ring machining: Rough turning: Turn the outer diameter and inner hole of the stainless steel blank (leaving a 0.2mm allowance for each), and cut the thickness to the design dimension + 0.1mm.

[0040] Finish turning: Turn to the design size (tolerance IT7), mill the second annular step (511) of the first clamping ring (51) and the trapezoidal annular groove (521) of the second clamping ring (52), and control the surface roughness of the sealing surface to Ra≤1.6μm; clean and set aside.

[0041] Sealing components and bearing pretreatment: Glyd ring processing: The PI inner ring sealing ring is laser-engraved with hydrodynamic grooves (groove width 0.2mm, depth 0.1mm), and the groove spacing deviation is ≤±0.01mm; the FFKMO ring is assembled with the PI inner ring and preheated in a 300℃ oven for 2 hours (to eliminate internal stress and improve dimensional stability).

[0042] Ceramic bearing treatment: Ultrasonic cleaning of the inner and outer rings and balls of the bearing (to remove oil and impurities), drying, and application of high-temperature grease (resistant to 300℃). Manually rotate the bearing to ensure it rotates smoothly without jamming.

[0043] Assembly process: The connecting pipe is first welded to the outer cylinder to avoid damage to internal components caused by high temperatures during subsequent welding.

[0044] Bearing assembly: Insert the two rows of zirconia bearings into the bearing mounting section (22) of the rotating inner tube (2) in sequence. After the inner bearing is close to the outer annular groove (222), insert the hole clamp (61) for positioning; the outer bearing is close to the annular clamp (221) to ensure that the distance deviation between the two bearings is ≤ ±0.03mm.

[0045] Sealing and clamping ring assembly: Insert the first sealing ring (41) into the first annular step (112) of the outer cylinder (1) (lip facing the fluid inlet); insert the second sealing ring (42) into the second annular step (511) of the first clamping ring (51), and then insert the first clamping ring (51) and the second clamping ring (52) into the circular groove (11) of the outer cylinder (1) in sequence, and press them into place using a 500N press (to ensure that the seals are not deformed and fit tightly).

[0046] Final assembly: Insert the inner rotating tube (2) with the bearing assembled into the circular groove (11) of the outer cylinder (1) coaxially, so that the outer bearing outer ring is inserted into the inner annular groove (111); install the shaft clamp (62) to limit the axial position of the inner rotating tube (2), manually rotate the inner tube to check the flexibility (rotation resistance ≤5N, no jamming); perform air tightness test (hold pressure at 5MPa for 30min, leakage ≤0.01mL / min).

[0047] Quality Inspection and Packaging: Dimensional inspection: Use a coordinate measuring machine to inspect the key dimensions of the outer cylinder (1), rotating inner tube (2), and clamping ring (such as the outer diameter of the outer cylinder and the diameter of the inner tube sealing section) to ensure that they meet the design requirements; use a surface roughness tester to inspect the roughness of the sealing surface.

[0048] Performance test: Place the connector in a 300℃ high temperature chamber and connect it to an aviation kerosene pipeline (pressure 5MPa). Drive the inner tube (2) to rotate at 100r / min for 2 hours to test the sealing performance (no leakage) and rotational stability (speed deviation ≤ ±5r / min).

[0049] Packaging: Qualified products are packaged in anti-static packaging, labeled with model number, batch number, and production date, and stored in the warehouse.

[0050] Component fabrication example: Outer cylinder (1): 06Cr19Ni10 stainless steel plate (thickness 25mm) is selected and processed by rough turning (outer circle φ20.5mm) - semi-finish milling (circular groove depth 15mm) - finish grinding (flow channel φ4mm, Ra0.8μm). The inner annular groove (111) has a groove width of 1.5mm (tolerance ±0.02mm).

[0051] Rotating inner tube (2): 06Cr19Ni10 stainless steel pipe (outer diameter φ10mm), after processing, the sealing section (21) has an outer diameter of φ9.5mm (IT5, tolerance -0.005mm), a roughness of Ra0.4μm, and an outer annular groove (222) with a groove depth of 1mm.

[0052] Sealing components: PI inner ring laser-engraved hydrodynamic grooves (0.5mm spacing), FFKMO ring (75 Shore A hardness), preheated at 300℃ for 2 hours after assembly, dimensional deviation ≤ ±0.03mm after cooling.

[0053] Ceramic bearing (3): Model 688CEF, zirconia full-ball structure, after cleaning, coated with high-temperature grease (model KLUBERISOFLEXTOPASL32), rotational resistance ≤3N.

[0054] Assembly example: The connecting pipe is first welded to the outer cylinder; Bearing assembly: Insert two zirconia bearings into the bearing mounting section (22) of the rotating inner tube (2) in sequence, and insert the bearing clip (61) (φ16) on the outer side of the inner bearing for positioning; check that the coaxiality of the two bearings is ≤0.02mm.

[0055] Sealing assembly: The first sealing ring (41) is inserted into the first annular step (112) of the outer cylinder (1), and the fit gap is checked with a feeler gauge to be ≤0.01mm; the first pressing ring (51) (with the second sealing ring 42) and the second pressing ring (52) are pressed into place with a 500N press (pressing stroke 5mm) to ensure that there is no loosening after pressing.

[0056] Assembly: Rotate the inner tube (2) into the outer tube (1). After the outer ring of the bearing is inserted into the inner annular groove (111), install the shaft clip (62) (φ48). Manually rotate the inner tube. The rotation is flexible and without jamming (vibration amplitude ≤0.1mm when the speed is 100r / min).

[0057] Performance test example: High temperature and high pressure test: The connector was placed in a 300℃ high temperature chamber (model BINDERFD115), connected to an aviation kerosene (RP-3) pipeline, the pressure was set to 5MPa, and the inner tube was driven to rotate at 100r / min for 2 hours. The test was then performed by an ultrasonic leak detector (model SONATESTULTRAPROBE15000), and no leaks were found.

[0058] Wear test: After 100 hours of continuous operation, the wear depth of the Glyd ring was measured to be ≤0.05mm, and the sealing performance still met the requirement of 5MPa pressure holding for 30min without leakage; the rotational resistance of the ceramic bearing was ≤4N, with no obvious wear.

Claims

1. A high-temperature, high-pressure fluid rotary sealing joint, characterized in that, The assembly includes an outer cylinder (1), a rotating inner tube (2), a ceramic bearing assembly (3), a sealing assembly, a clamping ring, and a limiting component. The outer cylinder (1) is made of stainless steel, with a circular groove (11) at one end and a radial flow channel (12) at the other end. The bottom of the circular groove (11) is connected to the radial flow channel (12) through an axial flow channel (13). The circular groove (11) has an inner annular groove (111) near the opening, and a first annular step (112) at the bottom of the circular groove (11). The rotating inner tube (2) is coaxially inserted into the circular groove (11) and includes a sealing section (21) and a bearing mounting section (22). One end of the bearing mounting section (22) has an annular retaining plate (221), and the other end has an outer annular groove (222). The ceramic bearing assembly (3) consists of two rows of zirconia full-ball bearings, installed on the bearing mounting section (22). The inner ring of the outer bearing is made of... The annular mounting plate (221) limits the inner ring of the inner bearing, which is limited by the limiting member in the outer annular groove (222). The outer rings of the two rows of bearings are limited by the limiting member in the inner annular groove (111). The sealing assembly includes a first sealing ring (41) and a second sealing ring (42), both of which are rotating Glyd rings for shafts, composed of a PI inner ring sealing ring and an FFKMO type ring. The first sealing ring (41) is installed in the first annular step (112), and the second sealing ring (42) is installed on the clamping ring. The clamping ring consists of two stainless steel ring components, which are installed in the circular groove (11) in sequence. The limiting member includes a hole clamp (61) and a shaft clamp (62). The hole clamp is installed in the outer annular groove (222), and the shaft clamp (62) is installed in the inner annular groove (111). A connecting pipe (14) is installed at the outer end of the radial flow channel (12) as a fluid outlet.

2. The rotary sealing joint according to claim 1, characterized in that, The outer cylinder (1) has a maximum outer diameter of Ф20mm and a length of 28.5mm; the rotating inner tube (2) has an outer diameter of Ф9.5mm and a length of 25mm, and the outer surface roughness of the sealing section (21) is ≤0.4μm; the outer cylinder (1) is made of 06Cr19Ni10 stainless steel; the inner flow channel size of the rotating inner tube is 4mm, and the zirconia full ball bearing model is 688CEF; the clamping ring is a 06Cr19Ni10 stainless steel ring component.

3. The rotary sealing joint according to claim 1, characterized in that, The rotating glyph has a continuous hydrodynamic groove on its sealing lip, a pressure relief groove on its end face, and a concave shape on its back. The clamping ring includes a first clamping ring (51) and a second clamping ring (52). The first clamping ring (51) has a second annular step (511) on its outer side. The second sealing ring (42) is installed in the second annular step (511). The second clamping ring (52) has a trapezoidal annular groove (521) on its outer side.

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