Rotary seal for a pneumatic wheel bearing

Abstract

The application provides a rotary seal of a pneumatic wheel hub bearing, which comprises a mounting seat, a magnetic seal ring, an air inlet pipe and an air outlet piece. The mounting seat is installed at a flange part of an inner ring of the wheel hub bearing and is connected with the air outlet piece. Two ends of the magnetic seal ring are connected with the mounting seat and the air inlet pipe respectively. The magnetic seal ring comprises a magnetic block for providing pre-tightening force. An intermediate section, which is connected with the air inlet pipe and the air outlet piece respectively, is formed between the mounting seat and the magnetic seal ring. The rotary seal of the pneumatic wheel hub bearing can solve the problems of insufficient sealing force and leakage in the starting stage.

Description

Technical Field

[0001] This invention relates to the field of pneumatic wheel hub bearings, and in particular to a rotary seal for pneumatic wheel hub bearings. Background Technology

[0002] With the increasing demand for adaptability to complex road conditions in commercial vehicles and special-purpose vehicles, central tire inflation / deflation systems have been widely promoted and applied. These systems allow for real-time adjustment of tire pressure based on road conditions, improving off-road capability, reducing tire wear, and effectively optimizing overall fuel economy. This has made them a core component of heavy-duty and off-road vehicles. As a core component of the wheel-side inflation / deflation system, the pneumatic wheel hub bearing needs to achieve airflow and dynamic sealing between the stationary inflation / deflation pipeline and the rotating wheel hub component. Its rotational sealing performance directly determines the reliability and service life of the entire inflation / deflation system. Current technology for rotating airflow sealing in pneumatic wheel hub bearings generally employs a traditional floating seal structure. This type of seal is a typical pressure-driven seal, its working principle relying on the air pressure of the medium inside the airflow to push the floating sealing ring, causing the two mating seals to... The end faces are pressed tightly together, and during equipment operation, a dynamic seal is achieved through an extremely thin air film formed between the sealing end faces. Under medium and high pressure conditions, this structure can provide sufficient sealing specific pressure by relying on sufficient medium pressure, and can achieve a good sealing effect. Therefore, it has been widely used in conventional inflation and deflation conditions. However, the floating seal of the existing technology has a significant condition dependence. Its sealing force depends entirely on the air pressure inside the air circuit. When the system is in a low-pressure condition (usually referring to an air pressure below 2 bar), such as during the system startup phase, the initial air pressure in the air circuit is insufficient to push the floating sealing ring to generate sufficient axial preload, resulting in the sealing end faces not being able to fit tightly together, with a small fit gap, which in turn causes air circuit leakage. This leakage problem will directly lead to slow tire pressure build-up during the start-up phase of the inflation and deflation system, a significant reduction in inflation and deflation efficiency, and in severe cases, even failure to reach the target tire pressure, affecting the inflation effect. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a rotary seal for an inflatable wheel hub bearing, which can solve the problems of insufficient sealing force and leakage during the startup phase.

[0004] To achieve the above objectives, the present invention provides a rotary seal for an inflatable wheel hub bearing, which further includes a mounting base, a magnetic sealing ring, an air inlet pipe, and an air outlet. The mounting base is installed at the flange portion of the inner ring of the wheel hub bearing and connected to the air outlet. The two ends of the magnetic sealing ring are respectively connected to the mounting base and the air inlet pipe. The magnetic sealing ring includes a magnetic block for providing preload, and an intermediate section is formed between the mounting base and the magnetic sealing ring, with the two ends respectively connected to the air inlet pipe and the air outlet.

[0005] The advantages of the above technical solution are: It includes a mounting base, a magnetic sealing ring, an air inlet pipe, and an air outlet. A middle section is formed between the mounting base and the magnetic sealing ring, with both ends connected to the air inlet pipe and the air outlet respectively. The magnetic sealing ring connects one end to the mounting base and the other to the air inlet pipe. Its built-in magnetic block continuously provides a stable pre-tightening force to the sealing ring and the mounting base. Whether under low-pressure conditions or during startup, it maintains a tight fit between the magnetic sealing ring and the mounting base, preventing leakage due to insufficient air pressure, unlike traditional floating seals. This effectively avoids the problem of slow tire pressure build-up caused by leakage.

[0006] The present invention can be further configured such that: the magnetic sealing ring includes a connecting groove for connecting the air intake pipe, the connecting groove includes a bottom surface located at the bottom and an air intake located at the bottom surface, the air intake forming a connection between the air intake pipe and the intermediate section. By further designing the magnetic sealing ring, a connecting groove is created to connect it to the air intake pipe. Furthermore, through the bottom surface and the air intake port, the airflow directly applies pressure to the bottom surface of the connecting groove during the intake process, thus tightly pressing the magnetic sealing ring onto the mounting base. This creates a dual sealing effect of magnetic pre-tightening and airflow pressure. This design not only ensures basic sealing during low-pressure and startup phases using the magnetic block, but also dynamically enhances the sealing performance using the pressure of the intake airflow. The greater the airflow, the stronger the clamping force, and the more reliable the seal, effectively preventing loosening and leakage caused by air pressure changes during the intake process.

[0007] The present invention can be further configured such that: the mounting base includes an annular protrusion, the magnetic sealing ring includes an annular groove, the annular groove is sleeved on the protrusion, and the magnetic block is disposed at the bottom of the annular groove and is disposed opposite to the protrusion.

[0008] By further designing the mounting base, the annular protrusion on the mounting base is interlocked with the annular groove of the magnetic sealing ring, achieving radial positioning and axial fit between the two. This simplifies assembly, ensures high coaxiality, and effectively reduces the impact of assembly deviations on sealing performance. Simultaneously, the magnetic block is positioned at the bottom of the annular groove and arranged opposite to the protrusion, allowing the magnetic force to act directly and evenly on the protrusion, ensuring a stable and uniform pre-tightening force between the magnetic sealing ring and the mounting base, thereby guaranteeing sealing reliability under low-pressure conditions.

[0009] The present invention can be further configured such that: a first recess extending circumferentially is provided at both the inner and outer diameters of the protrusion, and a first auxiliary sealing ring is provided in the first recess to elastically abut against the first recess and the annular groove.

[0010] By further designing the design, a first recess extending circumferentially is provided on both the inner and outer diameters of the protrusion, and a first auxiliary sealing ring is installed in the recess. This allows the auxiliary sealing ring to elastically abut against the annular grooves of both the recess and the magnetic sealing ring. Based on the main seal of the magnetic seal, two circumferential auxiliary seals are formed, further blocking the gas leakage channel and ensuring the sealing effect.

[0011] The present invention can be further configured such that: a second recess extending circumferentially is provided in the connecting groove, and a second auxiliary sealing ring is provided in the second recess that elastically abuts against the second recess and the air intake pipe.

[0012] By further designing the system, a second circumferential recess is provided in the connecting groove, and a second auxiliary sealing ring is installed in the recess. This allows the sealing ring to elastically abut against both the second recess and the air intake pipe, forming a complete and continuous circumferential seal at the air intake position. This reliably seals the gap between the air intake pipe and the connecting groove, preventing gas leakage from the air intake interface.

[0013] The present invention can be further configured such that: a connecting plate is provided on the intake pipe, the connecting plate is sleeved on the intake pipe, and the connecting plate is provided with threaded holes on both sides of the intake pipe for connecting with bolts to form the inner ring of the wheel hub bearing.

[0014] By further configuring the connection plate to the wheel hub bearing, the intake pipe can be securely fixed. After the bolts are tightened, the connection plate can provide stable axial and radial constraints on the intake pipe, preventing it from loosening, shifting, or deflecting when the bearing is running.

[0015] The present invention can be further configured to include a gasket, the gasket being sleeved on the intake pipe, and the gasket being disposed between the connecting plate and the inner ring of the wheel hub bearing.

[0016] By further configuring the gasket between the connecting plate and the inner ring of the wheel hub bearing, the clearance between the mating surfaces can be eliminated, preventing damage to the flange end face from the rigid connection and increasing the stability of the intake pipe.

[0017] The present invention can be further configured such that: the air outlet component includes a mounting block and an air guide component, the mounting block is embedded in the mounting base, and the air guide component is screwed to the mounting block.

[0018] By further configuring the connection, a screw connection is made between the screw connection and the mounting block embedded in the mounting base. On the one hand, the mounting block ensures the stability of the connection, and on the other hand, the screw connection facilitates disassembly and maintenance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a side view of an embodiment of the present invention; Figure 3 This is an embodiment of the present invention. Figure 2 Sectional view at point AA; Figure 4 This is an embodiment of the present invention. Figure 3 An enlarged view of part a; Figure 5 This is a schematic diagram of the structure of the abutment block according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the abutment block according to an embodiment of the present invention; The components include: mounting base 1; middle section 11; protrusion 12; first recess 121; magnetic sealing ring 2; magnetic block 21; connecting groove 22; bottom surface 221; air inlet 222; second recess 223; annular groove 23; friction ring 24; air inlet pipe 3; air outlet 4; mounting block 41; air guide 42; first auxiliary sealing ring 5; second auxiliary sealing ring 6; connecting plate 7; screw hole 71; and gasket 8. Detailed Implementation

[0020] An embodiment of the present invention, a rotary seal for a pneumatic wheel hub bearing, is provided as an example. Figure 1-6 As shown: It includes a mounting base 1, a magnetic sealing ring 2, an air inlet pipe 3, and an air outlet 4. The mounting base 1 is installed at the flange of the inner ring of the wheel hub bearing and connected to the air outlet 4. The two ends of the magnetic sealing ring 2 are respectively connected to the mounting base 1 and the air inlet pipe 3. The magnetic sealing ring 2 includes a magnetic block 21 for providing preload, and a middle section 11 is formed between the mounting base 1 and the magnetic sealing ring 2, with the two ends respectively connected to the air inlet pipe 3 and the air outlet 4.

[0021] The magnetic sealing ring 2 includes a connecting groove 22 for connecting the air intake pipe 3. The connecting groove 22 includes a bottom surface 221 located at the bottom and an air inlet 222 located at the bottom surface. The air inlet 222 forms a connection between the air intake pipe 3 and the intermediate section 11.

[0022] The mounting base 1 includes an annular protrusion 12, and the magnetic sealing ring 2 includes an annular groove 23, which is fitted onto the protrusion 12. The magnetic block 21 is disposed at the bottom of the annular groove 23 and is disposed opposite to the protrusion 12. In this embodiment, the magnetic sealing ring 2 is made of fluororubber to ensure elasticity, and its sealing surface has a roughness Ra≤0.8μm. The magnetic block 21 is made of neodymium iron boron material to provide a constant preload of 0.3N. The magnetic sealing ring 2 also includes a friction ring 24, which is disposed at the bottom of the annular groove 23 adjacent to the magnetic block 21 and abuts against the protrusion 12. The friction ring 24 reduces the friction between the magnetic sealing ring 2 and the protrusion 12.

[0023] The protrusion 12 is provided with a first recess 121 extending circumferentially at both the inner and outer diameters, and a first auxiliary sealing ring 5 is provided in the first recess 121 to elastically abut against the first recess 121 and the annular groove 23.

[0024] The connecting groove 22 is provided with a second recess 223 extending circumferentially, and a second auxiliary sealing ring 6 is provided in the second recess 223 to elastically abut against the second recess 223 and the air intake pipe 3.

[0025] The intake pipe 3 is provided with a connecting plate 7, which is sleeved on the intake pipe 3. The connecting plate 7 is provided with screw holes 71 on both sides of the intake pipe 3 for connecting with bolts to form a connection with the inner ring of the wheel hub bearing.

[0026] The intake pipe 3 is provided with a gasket 8, which is sleeved on the intake pipe 3 and is located between the connecting plate 7 and the inner ring of the wheel hub bearing. In this embodiment, the intake pipe 3 is made of seamless aluminum tube of 6063 aluminum alloy as the main body to avoid the deformation problem of flexible tubes, adapt to heavy-load vibration conditions, and the intake pipe 3 is provided on both opposite sides of the inner ring of the wheel hub bearing for easy connection.

[0027] The air outlet component 4 includes a mounting block 41 and an air guide component 42. The mounting block 41 is embedded in the mounting base 1, and the air guide component 42 is screwed to the mounting block 41.

[0028] The above examples are merely one preferred embodiment of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included within the protection scope of the present invention.

Claims

1. A rotary seal for an inflatable wheel hub bearing, characterized in that: It includes a mounting base, a magnetic sealing ring, an air inlet pipe, and an air outlet. The mounting base is installed at the flange of the inner ring of the wheel hub bearing and connected to the air outlet. The two ends of the magnetic sealing ring are respectively connected to the mounting base and the air inlet pipe. The magnetic sealing ring includes a magnetic block for providing preload, and a middle section is formed between the mounting base and the magnetic sealing ring, with the two ends respectively connected to the air inlet pipe and the air outlet.

2. The rotary seal of the pneumatic wheel hub bearing according to claim 1, characterized in that: The magnetic sealing ring includes a connecting groove for connecting the air intake pipe. The connecting groove includes a bottom surface at the bottom and an air inlet at the bottom surface. The air inlet forms a connection between the air intake pipe and the intermediate section.

3. The rotary seal of the pneumatic wheel hub bearing according to claim 2, characterized in that: The mounting base includes an annular protrusion, the magnetic sealing ring includes an annular groove, the annular groove is fitted onto the protrusion, and the magnetic block is disposed at the bottom of the annular groove and is disposed opposite to the protrusion.

4. The rotary seal of the pneumatic wheel hub bearing according to claim 2 or 3, characterized in that: The protrusion has a first recess extending circumferentially at both its inner and outer diameters, and a first auxiliary sealing ring is provided in the first recess to elastically abut against the first recess and the annular groove.

5. The rotary seal of the pneumatic wheel hub bearing according to claim 2 or 3, characterized in that: The connecting groove is provided with a second recess extending circumferentially, and the second recess is provided with a second auxiliary sealing ring that elastically abuts against the second recess and the air intake pipe.

6. The rotary seal of the pneumatic wheel hub bearing according to claim 1, characterized in that: The intake pipe is provided with a connecting plate, which is sleeved on the intake pipe. The connecting plate is provided with threaded holes on both sides of the intake pipe to cooperate with bolts to form a connection with the inner ring of the wheel hub bearing.

7. The rotary seal of the pneumatic wheel hub bearing according to claim 6, characterized in that: It includes a gasket, which is fitted onto the intake pipe and positioned between the connecting plate and the inner ring of the wheel hub bearing.

8. The rotary seal of the pneumatic wheel hub bearing according to claim 1, characterized in that: The air outlet component includes a mounting block and an air guide component. The mounting block is embedded in the mounting base, and the air guide component is screwed to the mounting block.

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