Rotary seal structure for vehicle door bridge central inflation and deflation system

Abstract

This invention belongs to the field of air circuit sealing for off-road vehicle chassis, and particularly to a rotary sealing structure for the central inflation / deflation system of a vehicle portal axle. It includes a stationary component, a rotating component, a bearing component, and a pair of dynamically and statically mating mirror-finish silicon carbide sealing components. The stationary and rotating components are coaxially arranged, with a central through-hole inside the stationary component for compressed air to pass through. The bearing component is positioned between the stationary and rotating components to support the free rotation of the rotating component relative to the stationary component. The mirror-finish silicon carbide sealing component includes a stationary ring and a rotating ring. The stationary ring is fixed to the stationary component, and the rotating ring is fixed to the rotating component. The mirror-finished end faces of the two rings are fitted together to form a gas sealing surface. This invention achieves a non-entangled connection between the vehicle body fixed pipeline and the portal axle rotating pipeline through the relative rotation of the stationary and rotating ends, avoiding pipeline twisting and breakage, and improving system reliability.

Description

Technical Field

[0001] This invention relates to the field of air circuit sealing technology for off-road vehicle chassis, and more particularly to a rotary sealing structure for the central inflation / deflation system of a vehicle portal axle. Background Technology

[0002] Hardcore off-road vehicles are often equipped with a central tire inflation / deflation system, which can adjust tire pressure in real time according to road conditions while driving, improving their ability to pass through complex terrains. The core pipeline of this system needs to extend from the fixed end of the vehicle body (frame / air tank) to the rotating end (axle half shaft / wheel hub) to realize the delivery of high-pressure gas to the tires.

[0003] The pain points in the existing technology are: 1. Risk of pipe entanglement: The axle rotates continuously with the wheel. If the pipe is directly rigidly connected, it will twist and entangle with the wheel rotation, eventually leading to pipe breakage and air leakage, making it impossible to achieve continuous inflation and deflation.

[0004] 2. The contradiction between high-pressure sealing and rotation: The working pressure of the central inflation and deflation system is usually above 0.5MPa. Ordinary rotary seals (such as rubber oil seals and ordinary mechanical seals) cannot simultaneously meet the dual requirements of "zero leakage of high-pressure gas" and "long-term low-resistance free rotation", which can easily lead to problems such as seal failure, leakage, wear and jamming.

[0005] 3. Poor adaptability to harsh working conditions: Off-road vehicles often operate in environments with mud, sand, gravel, and alternating high and low temperatures. Existing sealing structures are insufficient in their ability to resist impurities, wear, and impact, resulting in poor reliability and high maintenance costs. Traditional piping systems often use flexible hoses for direct connection, which cannot solve the entanglement problem caused by axle rotation and has a very short service life. Some ordinary rotary joints used are mostly rubber lip seals, which are only suitable for low-pressure scenarios and cannot withstand high-pressure gases above 0.5 MPa. In addition, the lips are prone to wear and aging, resulting in a short seal life. Some mechanical seal structures use metal-to-metal hard seals, but they are not optimized for axle rotation conditions, resulting in problems such as high rotational resistance, easy wear of the sealing surface, and poor impact resistance. They cannot meet the long-term use requirements of off-road vehicles. Existing structures do not integrate integrated designs such as anti-impurity intrusion, bearing support, and preload compensation, making the structure complex and inconvenient for installation and maintenance. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art and propose a rotary sealing structure for the central inflation / deflation system of a vehicle portal axle.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A rotary sealing structure for a central inflation / deflation system of a vehicle portal axle includes a stationary component, a rotating component, a bearing component, and a pair of dynamically and statically mating mirror-finished silicon carbide sealing components. The stationary component and the rotating component are arranged coaxially, and the stationary component has a through central air hole for passing compressed air. The bearing component is disposed between the stationary component and the rotating component, and is used to support the rotating component to rotate freely relative to the stationary component; The mirror-finished silicon carbide sealing component includes a stationary ring and a rotating ring. The stationary ring is fixed to the stationary component, and the rotating ring is fixed to the rotating component. The mirror-finished end faces of the two rings fit together to form a gas sealing surface. While bearing the gas pressure in the central vent, the rotating component is allowed to rotate relative to the stationary component, thereby achieving high-pressure gas sealing and preventing gas pipe entanglement.

[0008] Preferably, the stationary component is a fixed end used to connect to the inflation / deflation pipeline on the side of the vehicle body.

[0009] Preferably, the rotating component is a rotating end, used to connect to the inflation / deflation pipeline on the axle or wheel hub side, and rotates synchronously with the wheel.

[0010] Preferably, the bearing component is a rolling bearing, arranged outside the sealing component, to ensure coaxiality, reduce rotational resistance and prevent uneven wear of the sealing end face.

[0011] Preferably, both the stationary ring and the rotating ring are made of mirror-polished silicon carbide material, forming a high-precision, wear-resistant hard sealing pair that can maintain gas sealing under 0-3.0 MPa pressure.

[0012] Preferably, the central vent is a straight-through vent, where gas enters from one end of the stationary component, passes through the central region of the mirror-finished silicon carbide sealing component, and flows out from one end of the rotating component.

[0013] Preferably, it also includes an axial preload structure for applying a continuous axial preload force to the dynamic and static sealing rings, so that the sealing end faces are always in contact, compensating for wear and maintaining sealing performance.

[0014] Preferably, the stationary component has a long-axis structure. A sealing mounting seat is provided at one end of the stationary component near the rotating component for mounting a stationary ring. The stationary ring is interference-fitted / glued to the stationary component to ensure the flatness and perpendicularity of the sealing surface. A bearing mounting cavity is provided on the outer side of the sealing mounting seat for mounting bearing components, providing radial support for the rotating component and ensuring rotational coaxiality. A standard pipeline interface is provided at the outer end of the stationary component for connecting to the central inflation / deflation main pipeline on the side of the vehicle body. The mating surfaces of the stationary component and the rotating component are provided with a dustproof and mud-proof labyrinth seal structure to prevent external impurities from intruding into the sealing surface and bearing, thus improving reliability.

[0015] Preferably, the main body of the rotating component is a sleeve structure, coaxially sleeved on the outside of the stationary component, and the central hole is coaxially connected with the central hole of the stationary component to form a complete high-pressure gas channel. A sealing mounting seat is provided at one end of the rotating component near the stationary component for mounting the rotating ring. The rotating ring rotates synchronously with the rotating component and forms a pair of end face seals with the stationary ring.

[0016] Preferably, a spring preload component is installed on the rear side of the second sealing mounting base. The spring preload component has multiple sets of cylindrical helical compression springs installed inside. One end of the cylindrical helical compression spring presses against the spring seat of the rotating component, and the other end presses against the positioning structure on the stationary side. This provides a continuous and stable axial preload force for the two sets of silicon carbide sealing rings, compensates for the wear of the sealing surface, ensures that the sealing surface is always tightly fitted, and achieves high-pressure sealing. A standard pipeline interface is provided on the outer side of the rotating component for connecting the tire inflation / deflation pipeline on the portal axle side. A positioning structure is provided on the outer cylindrical surface of the rotating component for fixing it to the mounting base of the portal axle / wheel hub to ensure synchronous rotation with the wheel.

[0017] The beneficial effects of the rotary sealing structure for the central inflation / deflation system of a vehicle portal axle in this invention are as follows: 1. Completely solves the problem of pipe entanglement: By rotating the stationary end and the rotating end relative to each other, the fixed pipes of the vehicle body and the rotating pipes of the portal axle are connected without entanglement, avoiding pipe twisting and breakage, and improving system reliability.

[0018] 2. Excellent high-pressure sealing performance: The mirror-finish silicon carbide end face seal can stably withstand high-pressure gas of 0-3MPa, achieving zero-leakage sealing and meeting the working pressure requirements of the central inflation / deflation system.

[0019] 3. Low rotational resistance and long service life: The design of bearing support + silicon carbide hard seal results in extremely low rotational resistance, which does not affect the normal rotation of the wheel. At the same time, the high wear resistance of silicon carbide ensures a significant increase in seal life and reduces maintenance costs.

[0020] 4. Strong adaptability to extreme working conditions: Silicon carbide materials are corrosion-resistant, wear-resistant, high temperature resistant, and impact-resistant, and can adapt to the harsh environments of off-road vehicles such as mud, sand, gravel, high and low temperatures. Their reliability is far higher than that of traditional sealing structures.

[0021] 5. Compact structure and easy installation and maintenance: The integrated coaxial design is compact and occupies little space. It can be directly integrated into the portal axle / hub position, making installation convenient and maintenance simple. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the rotary sealing structure for the central inflation / deflation system of a vehicle portal axle proposed in this invention. Figure 2This is a schematic diagram of the connection between the rotating component and the bearing support component of the rotary sealing structure for the central inflation / deflation system of a vehicle portal axle proposed in this invention. Figure 3 This is a schematic diagram of the connection between the rotating component and the bearing support component of the rotary sealing structure for the central inflation / deflation system of a vehicle portal axle proposed in this invention.

[0023] In the diagram: 1. Stationary component; 2. Rotating component; 3. Bearing component; 4. Mirror-finished silicon carbide sealing component. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] Example 1 Reference Figures 1-3 A rotary sealing structure for a central inflation / deflation system of a vehicle portal axle, comprising a stationary component 1, a rotating component 2, a bearing component 3, and a pair of dynamically and statically fitted mirror silicon carbide sealing components 4. The stationary component 1 and the rotating component 2 are arranged coaxially. The stationary component 1 has a through central air hole for compressed air to pass through. The bearing component 3 is disposed between the stationary component 1 and the rotating component 2, and is used to support the rotating component 2 to rotate freely relative to the stationary component 1; The mirror silicon carbide sealing component 4 includes a stationary ring and a rotating ring. The stationary ring is fixed to the stationary component 1, and the rotating ring is fixed to the rotating component 2. The mirror end faces of the two rings fit together to form a gas sealing surface. While bearing the gas pressure in the central vent, the rotating component is allowed to rotate relative to the stationary component, thereby achieving high-pressure gas sealing and preventing gas pipe entanglement.

[0026] In this embodiment, the stationary component 1 is a fixed end used to connect the inflation / deflation pipeline on the side of the vehicle body.

[0027] In this embodiment, the rotating component 2 is a rotating end used to connect the inflation / deflation pipeline on the axle or wheel hub side, and rotates synchronously with the wheel.

[0028] In this embodiment, the bearing component 3 is a rolling bearing, which is arranged outside the sealing component to ensure coaxiality, reduce rotational resistance and prevent uneven wear of the sealing end face.

[0029] In this embodiment, both the stationary ring and the moving ring are made of mirror-polished silicon carbide material, forming a high-precision, wear-resistant hard seal pair that can maintain gas sealing under pressures of 0-3.0 MPa.

[0030] In this embodiment, the central vent is a straight-through air passage. Gas enters from one end of the stationary component 1, passes through the central region of the mirror silicon carbide sealing component 4, and flows out from one end of the rotating component 2.

[0031] In this embodiment, an axial preload structure is also included to apply a continuous axial preload force to the dynamic and static sealing rings, so that the sealing end faces are always in contact, compensating for wear and maintaining sealing performance.

[0032] In this embodiment, the stationary component 1 has a long-axis structure. A sealing mounting seat is provided at one end of the stationary component 1 near the rotating component 2 for mounting a stationary ring. The stationary ring is interference-fitted / glued to the stationary component 1 to ensure the flatness and perpendicularity of the sealing surface. A bearing mounting cavity is provided on the outer side of the sealing mounting seat for mounting a bearing component 3 to provide radial support for the rotating component 2 and ensure rotational coaxiality. A standard pipeline interface is provided at the outer end of the stationary component 1 for connecting to the central inflation / deflation main pipeline on the side of the vehicle body. The mating surfaces of the stationary component 1 and the rotating component 2 are provided with a labyrinth seal structure that is dustproof and mudproof to prevent external impurities from entering the sealing surface and bearing, thereby improving reliability.

[0033] In this embodiment, the main body of the rotating component 2 is a sleeve structure, which is coaxially sleeved on the outside of the stationary component 1. The central hole is coaxially connected with the central hole of the stationary component 1 to form a complete high-pressure gas channel. A sealing mounting seat 2 is provided at one end of the rotating component 2 near the stationary component 1 for installing the rotating ring. The rotating ring rotates synchronously with the rotating component 2 and forms a pair of end face seals with the stationary ring.

[0034] In this embodiment, a spring preload component is installed on the rear side of the sealing mounting base 2. The spring preload component has multiple sets of cylindrical helical compression springs installed inside. One end of the cylindrical helical compression spring presses against the spring seat of the rotating component 2, and the other end presses against the positioning structure on the stationary side, providing a continuous and stable axial preload force for the two sets of silicon carbide sealing rings, compensating for the wear of the sealing surface, ensuring that the sealing surface is always tightly fitted, and realizing high-pressure sealing. A standard pipeline interface is provided on the outer side of the rotating component 2 for connecting the tire inflation / deflation pipeline on the portal axle side. A positioning structure is provided on the outer cylindrical surface of the rotating component 2 for fixing it to the mounting base of the portal axle / wheel hub to ensure synchronous rotation with the wheel.

[0035] Bearing component 3 uses two sets of high-precision rolling bearings, which are installed in the bearing mounting cavity between the stationary component and the rotating component.

[0036] The function of bearings is to provide radial support for rotating parts, ensure the coaxiality of stationary and rotating parts, and prevent uneven wear on the sealing surfaces.

[0037] It significantly reduces rotational resistance, ensuring that rotating parts can rotate freely and smoothly with the wheels without jamming.

[0038] It withstands the radial load transmitted by the axle, protects the sealing surface from additional radial forces, and extends the seal life.

[0039] The bearing is a sealed bearing with built-in lubricating oil to prevent external mud, water, and impurities from entering, thus extending the bearing's service life.

[0040] The mirror-finished silicon carbide sealing component 4 consists of two sets of mirror-finished silicon carbide (SiC) sealing rings, one set being a stationary ring and the other a moving ring. The opposite end faces of the two sets of sealing rings are machined with high precision mirror finish (flatness ≤ 0.001 mm, roughness Ra ≤ 0.05 μm).

[0041] Sealing principle: Under the combined action of spring preload and high-pressure gas pressure, two sets of mirror-finished silicon carbide sealing rings fit tightly together to form a sealing surface, blocking the leakage channel of high-pressure gas; at the same time, silicon carbide material has extremely high hardness, wear resistance, corrosion resistance and high temperature resistance, and can achieve extremely low wear rate under relative rotation conditions, ensuring long-term sealing reliability.

[0042] Sealing performance: It can withstand high-pressure gas and achieve zero-leakage sealing. At the same time, it allows the two sets of sealing rings to rotate relative to each other at the axle speed. The rotational resistance is extremely low and does not affect the normal rotation of the wheels.

[0043] Material advantages: Silicon carbide has a hardness far exceeding that of traditional sealing materials (such as rubber and stainless steel), and has extremely strong resistance to wear, impact, and corrosion. It can adapt to extreme working conditions such as mud, sand, gravel, high and low temperatures in off-road vehicles, and its sealing life is 5-10 times that of traditional sealing structures.

[0044] (a) Installation method 1. Fix the stationary component 1 to the portal axle mounting base with bolts, and connect it to the central inflation / deflation main pipeline on the side of the vehicle body, ensuring that there is no relative movement at the fixed end.

[0045] 2. Fix the rotating component 2 to the mounting base of the portal axle / wheel hub with bolts to ensure that the rotating component rotates synchronously with the wheel, and connect the tire inflation / deflation line on the axle side.

[0046] 3. After installation, check the coaxiality of the stationary and rotating parts to ensure smooth bearing operation and proper sealing surface contact.

[0047] 4. Conduct a high-pressure airtightness test: Introduce 1.0MPa compressed air into the center hole, maintain the pressure for 120 minutes, check for no leakage, and ensure that rotating part 2 can rotate freely, which indicates that the installation is qualified.

[0048] (II) Work Process 1. When the vehicle is in motion, the portal axle / wheel hub drives the rotating component 2 to rotate synchronously, while the stationary component 1 remains fixed. The two sets of mirror silicon carbide sealing rings rotate relative to each other. Under the action of spring preload and high-pressure gas pressure, the sealing surfaces are always tightly fitted, preventing high-pressure gas leakage.

[0049] 2. The high-pressure air of the central inflation / deflation system enters through the central hole of the stationary component, passes through the central channel of the two sets of sealing rings, and is delivered to the central hole of the rotating component 2. Finally, it is delivered to the tire through the portal axle side pipeline to realize the inflation / deflation of the tire.

[0050] 3. The spring preload component continuously provides axial preload to the sealing surface, compensating for wear on the sealing surface and ensuring long-term stability of sealing performance.

[0051] 4. The bearing support components ensure the coaxiality of rotating parts, reduce rotational resistance, and the labyrinth seal structure prevents external mud, water, sand and gravel from entering the sealing surface and bearing, thus improving the overall service life.

[0052] (III) Verification of Technical Parameters Working pressure: 0-3MPa, with a maximum pressure of 3.0MPa.

[0053] Operating speed: Suitable for the highest speed of the gantry axle of off-road vehicles (≤3000r / min).

[0054] Sealing performance: Zero leakage.

[0055] Operating temperature: -70℃~+180℃, adaptable to extreme high and low temperature environments.

[0056] Service life: Under off-road conditions, the sealing life is ≥15,000 hours, which is far longer than that of traditional sealing structures.

[0057] Example 2 The difference from Example 1 is that the sealing ring material can be selected from other high-performance ceramic materials such as silicon nitride and tungsten carbide, depending on the working conditions.

[0058] Disc springs and wave springs can be used to replace cylindrical helical springs in the spring preload component to optimize the preload characteristics.

[0059] Adding a lubricating medium (such as a solid lubricant) between the sealing surfaces further reduces rotational resistance and extends seal life.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rotary sealing structure for a central inflation / deflation system of a vehicle portal axle, characterized in that, It includes a stationary component (1), a rotating component (2), a bearing component (3), and a pair of mirror-finished silicon carbide sealing components (4) that are dynamically and statically matched. The stationary component (1) and the rotating component (2) are arranged coaxially. The stationary component (1) has a through central air hole for passing compressed air. The bearing component (3) is disposed between the stationary component (1) and the rotating component (2) to support the rotating component (2) to rotate freely relative to the stationary component (1); The mirror silicon carbide sealing component (4) includes a stationary ring and a rotating ring. The stationary ring is fixed to the stationary component (1), and the rotating ring is fixed to the rotating component (2). The mirror end faces of the two rings fit together to form a gas sealing surface. While bearing the gas pressure in the central vent, the rotating component is allowed to rotate relative to the stationary component, thereby achieving high-pressure gas sealing and preventing the gas pipe from tangling.

2. The rotary sealing structure for the central inflation / deflation system of a vehicle portal axle according to claim 1, characterized in that, The stationary component (1) is a fixed end used to connect the inflation / deflation pipeline on the side of the vehicle body.

3. The rotary sealing structure for the central inflation / deflation system of a vehicle portal axle according to claim 2, characterized in that, The rotating component (2) is a rotating end used to connect the air inlet / outlet pipe on the axle or wheel hub side and rotates synchronously with the wheel.

4. The rotary sealing structure for the central inflation / deflation system of a vehicle portal axle according to claim 3, characterized in that, The bearing component (3) is a rolling bearing, arranged outside the sealing component, to ensure coaxiality, reduce rotational resistance and prevent uneven wear of the sealing end face.

5. The rotary sealing structure for the central inflation / deflation system of a vehicle portal axle according to claim 4, characterized in that, Both the stationary ring and the moving ring are made of mirror-polished silicon carbide material, forming a high-precision, wear-resistant hard seal pair that can maintain gas sealing under pressures of 0-3.0 MPa.

6. The rotary sealing structure for a central inflation / deflation system of a vehicle portal axle according to claim 5, characterized in that, The central vent is a straight-through air passage. Gas enters from one end of the stationary component (1), passes through the central area of ​​the mirror silicon carbide sealing component (4), and flows out from one end of the rotating component (2).

7. The rotary sealing structure for a central inflation / deflation system of a vehicle portal axle according to claim 6, characterized in that, It also includes an axial preload structure, which is used to apply a continuous axial preload to the dynamic and static sealing rings, so that the sealing end faces are always in contact, compensating for wear and maintaining sealing performance.

8. The rotary sealing structure for a central inflation / deflation system of a vehicle portal axle according to claim 7, characterized in that, The stationary component (1) has a long shaft structure. A sealing mounting seat is provided at one end of the stationary component (1) near the rotating component (2) for installing a stationary ring. The stationary ring is interference-fitted / glued to the stationary component (1) to ensure the flatness and perpendicularity of the sealing surface. A bearing mounting cavity is provided on the outer side of the sealing mounting seat for installing a bearing component (3) to provide radial support for the rotating component (2) and ensure rotational coaxiality. A standard pipeline interface is provided at the outer end of the stationary component (1) for connecting to the central inflation / deflation main pipeline on the side of the vehicle body. The mating surfaces of the stationary component (1) and the rotating component (2) are provided with a labyrinth seal structure that is dustproof and mudproof to prevent external impurities from entering the sealing surface and bearing, thereby improving reliability.

9. The rotary sealing structure for a central inflation / deflation system of a vehicle portal axle according to claim 8, characterized in that, The main body of the rotating component (2) is a sleeve structure, which is coaxially sleeved on the outside of the stationary component (1). The central hole is coaxially connected with the central hole of the stationary component (1) to form a complete high-pressure gas channel. A sealing mounting seat is provided at one end of the rotating component (2) near the stationary component (1) for installing the rotating ring. The rotating ring rotates synchronously with the rotating component (2) and forms a pair of end face seals with the stationary ring.

10. The rotary sealing structure for a central inflation / deflation system of a vehicle portal axle according to claim 9, characterized in that, The rear side of the sealing mounting base 2 is equipped with a spring preload component: multiple sets of cylindrical helical compression springs are installed inside the spring preload component. One end of the cylindrical helical compression spring presses against the spring seat of the rotating component (2), and the other end presses against the positioning structure on the stationary side, providing continuous and stable axial preload force for the two sets of silicon carbide sealing rings, compensating for the wear of the sealing surface, ensuring that the sealing surface is always tightly fitted, and realizing high-pressure sealing. The outer side of the rotating component (2) is provided with a standard pipeline interface for connecting the tire inflation / deflation pipeline on the portal axle side. The outer cylindrical surface of the rotating component (2) is provided with a positioning structure for fixing to the mounting base of the portal axle / wheel hub, ensuring synchronous rotation with the wheel.

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