A high durability rotary union

Abstract

The utility model discloses a high durability swivel joint, including sleeve metal piece and with the plastic connecting piece of metal piece cooperation, the inner wall of metal piece is equipped with the buckle that bulges inwards to the circumference, the top end of plastic connecting piece is distributed with N elastic clamping hook that is adapted with the buckle to the circumference, wherein 2N4, the axial gap between the clamping surface of elastic clamping hook and the clamping surface of buckle has after assembling, and axial gap is configured as: when the elastic clamping hook occurs elastic deformation, provides space for deformation to maintain the effective clamping state between elastic clamping hook and buckle, prevents the connection from loosening. The strength of insufficient, poor stability, poor durability etc. of the existing small size swivel joint have been solved.

Description

Technical Field

[0001] This utility model relates to the field of rotary joint technology, and in particular to a highly durable rotary joint. Background Technology

[0002] As a key component connecting the fixed and rotating flow paths, the reliability of rotary joints directly affects the stability of the fluid transfer system. Traditional rotary joints generally employ a design with six or more sets of hooks and interlocking metal parts. However, for small-sized joints, this design has the following drawbacks:

[0003] Firstly, the small size of the connector forces a reduction in the size of individual hook structures. Under the constraint of circumferential space, excessively small hooks not only fail to provide sufficient axial pull-out force, but their weak structures are also prone to irreversible plastic deformation or even fracture under stress. Especially under rotational conditions, deformed hooks lose their ability to restrain metal parts, causing a surge in the risk of connection failure.

[0004] Secondly, manufacturing tolerances and assembly errors can create irregular, sloping structures at the mating interface. Under dynamic conditions, this structure generates radial forces that can cause the clips to slip out; even slight external forces can trigger a chain reaction of loosening. More seriously, the hard contact between the plastic hook and the metal clip easily leads to stress concentration, accelerating material fatigue and failure.

[0005] While existing technologies attempt to compensate for strength by increasing the number of catches, this exacerbates spatial conflicts and uneven stress distribution. This contradiction is particularly pronounced in small-sized rotary joints, severely restricting the joint's durability and connection reliability, necessitating a new design to address these issues. Utility Model Content

[0006] To address the shortcomings of the existing technology, this utility model provides a highly durable rotary joint to solve the problems of insufficient strength, poor stability, and poor durability of existing small-sized rotary joints.

[0007] This utility model is achieved using the following technical solution:

[0008] A highly durable rotary joint includes a sleeve-shaped metal part and a plastic connector that mates with the metal part. The inner wall of the metal part is provided with an inwardly protruding buckle. The top of the plastic connector is circumferentially distributed with N elastic hooks that are adapted to the buckle, where 2≤N≤4. After assembly, there is an axial gap between the engagement surface of the elastic hook and the engagement surface of the buckle. The axial gap is configured to provide space for deformation when the elastic hook undergoes elastic deformation, so as to maintain an effective engagement state between the elastic hook and the buckle and prevent the connection from loosening.

[0009] Furthermore, the N elastic hooks are circumferentially distributed at equal intervals.

[0010] Furthermore, the axial clearance ranges from 0.5mm to 0.8mm.

[0011] Furthermore, the axial clearance is configured such that after the elastic hook undergoes elastic deformation within the expected range, the size of the axial clearance decreases, but still maintains a preset clearance.

[0012] Furthermore, the number of elastic hooks is four.

[0013] Furthermore, the elastic hook includes a root and a cantilever-beam-shaped hook body, wherein the thickness of the root is greater than the thickness of the hook body.

[0014] Furthermore, the engaging end of the buckle has a rounded corner structure.

[0015] Furthermore, the buckle has a guide ramp for guiding the resilient hook to slide in.

[0016] Furthermore, a sealing ring is provided between the connecting ends of the metal part and the plastic connector, and the sealing ring is in close contact with the guide slope.

[0017] Furthermore, the sealing ring has a lip-shaped cross-section.

[0018] Compared with the prior art, the beneficial effects of this utility model include at least the following:

[0019] This invention limits the number of elastic hooks to 2 to 4, avoiding excessively small individual hook sizes in small-sized structures due to an excessive number of hooks. This improves the structural strength of each individual elastic hook and reduces the risk of plastic deformation or breakage. In the snap-fit ​​structure between the sleeve-shaped metal part and the plastic connector, the circumferential snaps on the inner wall of the metal part and the elastic hooks at the top of the plastic connector interlock. The axial clearance design ensures that the elastic hooks retain sufficient space to maintain the engaged state even under stress and deformation, preventing them from detaching due to excessive deformation. The axial clearance not only allows for stress absorption through elastic deformation but also ensures that the contact surface between the elastic hook and the snap is always within the effective constraint range, preventing loosening due to insufficient rebound during rotation. This significantly improves connection reliability and product lifespan. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of a highly durable rotary joint according to an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the metal part according to an embodiment of the present utility model;

[0022] Figure 3 This is a schematic diagram of the plastic connector according to an embodiment of the present utility model;

[0023] In the diagram: 1. Metal part; 11. Buckle; 111. Guide slope; 2. Plastic connector; 21. Elastic hook; 211. Root; 212. Hook body; 3. Axial clearance; 4. Sealing ring. Detailed Implementation

[0024] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0025] The terms used to describe position and direction in this utility model are illustrated with the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this utility model.

[0026] like Figures 1 to 3 As shown, this utility model provides a highly durable rotary joint, including a sleeve-shaped metal part 1 and a plastic connector 2 that mates with the metal part 1. The inner wall of the metal part 1 is provided with an inwardly protruding buckle 11. The top of the plastic connector 2 is circumferentially distributed with N elastic hooks 21 that are adapted to the buckles 11, where 2≤N≤4. After assembly, there is an axial gap 3 between the engaging surface of the elastic hook 21 and the engaging surface of the buckle 11. The axial gap 3 is configured to provide space for deformation when the elastic hook 21 undergoes elastic deformation, so as to maintain the effective engaging state between the elastic hook 21 and the buckle 11 and prevent the connection from loosening.

[0027] In this embodiment, by limiting the number of elastic hooks 21 to 2 to 4, the size of each individual elastic hook 21 is prevented from becoming too small due to an excessive number of hooks in a small-sized structure. This improves the structural strength of each individual elastic hook 21 and reduces the risk of plastic deformation or fracture. In the latching structure between the sleeve-shaped metal part 1 and the plastic connector 2, the circumferential latches 11 on the inner wall of the metal part 1 and the elastic hooks 21 at the top of the plastic connector 2 interlock. Through the design of the axial gap 3, sufficient space is retained for the elastic hooks 21 to maintain the engaged state when subjected to deformation, preventing the elastic hooks 21 from disengaging from the latches 11 due to excessive deformation. The configuration of the axial gap 3 not only allows elastic deformation to absorb stress, but also ensures that the contact surface between the elastic hooks 21 and the latches 11 is always within the effective constraint range through the gap allowance, avoiding the problem of loosening due to insufficient rebound of the elastic hooks 21 during rotational movement.

[0028] It should be noted that the number of elastic hooks 21 is limited to 2 to 4. Specifically, they can be integrally molded onto the top of the plastic connector 2 using an injection molding process. This quantity range ensures that each elastic hook 21 has sufficient cross-sectional area to resist breakage in small-sized structures. (Reference) Figure 1 , Figure 1 In this context, S represents axial clearance 3, which refers to the space between the engaging surfaces that is not completely filled. This clearance allows the elastic hook 21 to displace under pressure without disengaging from the latch 11.

[0029] This invention reduces the number of elastic hooks 21 and adds an axial gap 3, increasing the volume of the elastic hooks 21 by approximately 50% within the same installation space, effectively distributing the load. In existing technologies, the design of the elastic hooks 21 and the latch 11 being completely fitted together can easily lead to rigid compression under dynamic conditions. This embodiment, however, transforms rigid contact into elastic contact through a gap design, eliminating the risk of misalignment caused by assembly errors. It effectively solves the problem of insufficient strength in miniature rotary joints caused by an excessive number of elastic hooks 21, allowing each individual elastic hook 21 to absorb energy through elastic deformation under stress, preventing permanent damage. The introduction of the axial gap 3 ensures stable contact of the engagement structure under dynamic conditions, effectively suppressing the slippage force generated by rotational motion, significantly improving connection reliability and product lifespan.

[0030] In a preferred embodiment, the N elastic hooks 21 are circumferentially distributed at equal intervals. By setting the elastic hooks 21 to be circumferentially distributed at equal intervals, each elastic hook 21 forms a symmetrical mechanical support structure in the circumferential direction. This equidistant distribution feature allows each elastic hook 21 to evenly distribute the force when the rotary joint is subjected to circumferential loads, avoiding plastic deformation caused by overload of individual elastic hooks 21 due to uneven distribution. The equidistant layout also optimizes the structural arrangement within the limited circumferential space. Under the premise of ensuring the minimum number of elastic hooks 21 (2≤N≤4), the spatial symmetry design effectively suppresses the off-center loading phenomenon that may occur during assembly, ensuring that the contact pressure distribution between each elastic hook 21 and the metal part 1 buckle 11 is balanced, thereby improving the overall stability of the connection structure.

[0031] In a preferred embodiment, the axial clearance 3 has a size range of 0.5mm-0.8mm.

[0032] In this embodiment, the axial clearance 3 is limited to a specific range to provide precise spatial control for the elastic deformation of the elastic hook 21. When the axial clearance 3 is set to 0.5mm-0.8mm, it ensures that the elastic hook 21 has sufficient deformation margin under normal stress to avoid plastic deformation, while also avoiding the risk of engagement failure due to excessive clearance. The selection of this size range is based on a balance between the material's elastic modulus and the structural strength of the elastic hook 21, ensuring that within the expected deformation range, the engagement surfaces can release stress concentration through the clearance while maintaining sufficient contact pressure to maintain an effective engagement state. In particular, the lower limit of this value range of 0.5mm prevents assembly interference caused by excessively small clearance, while the upper limit of 0.8mm avoids connection loosening caused by excessively large clearance. By limiting the clearance range, deformation space and connection reliability are balanced in a small-sized structure, solving the problem of elastic hook 21 failure due to size reduction.

[0033] In a preferred embodiment, the axial gap 3 is configured such that after the elastic hook 21 undergoes elastic deformation within the expected range, the size of the axial gap 3 decreases, but still maintains a preset gap.

[0034] In this embodiment, reducing the axial clearance 3 means allowing the elastic hook 21 to undergo elastic deformation under normal force to absorb stress. By maintaining the preset clearance, both excessive clearance leading to engagement failure and complete disappearance of the clearance causing plastic deformation or fracture are avoided. The design of reserving a preset clearance ensures that the elastic hook 21 maintains an effective engagement state during repeated deformation, solving the risk of connection loosening due to tolerance accumulation or material creep in small-sized structures, and improving the stability and reliability of the rotary joint during long-term use. Specifically, the preset clearance in this embodiment is preferably 0.2mm-0.3mm.

[0035] In a preferred embodiment, the number of elastic hooks 21 is four. By limiting the number of elastic hooks 21 to four, the structural space layout is optimized while ensuring engagement stability. Compared to the traditional design using six or more elastic hooks 21, the setting of four elastic hooks 21 allows each elastic hook 21 to achieve a larger structural size within a limited circumferential space, thereby significantly improving the tensile strength and deformation resistance of a single elastic hook 21. Combined with the equidistant circumferential distribution, this configuration ensures that each elastic hook 21 evenly distributes the load, avoiding the risk of plastic deformation due to local stress concentration. At the same time, the layout of four elastic hooks 21 satisfies the constraint condition of 2≤N≤4, and by reducing the number of elastic hooks 21, it reduces the tolerance accumulation effect caused by multiple hooks during assembly, thereby maintaining an effective engagement state between the elastic hooks 21 and the metal part 1 latch 11.

[0036] In a preferred embodiment, the elastic hook 21 includes a root portion 211 and a cantilever beam-shaped hook body 212, wherein the thickness of the root portion 211 is greater than the thickness of the hook body 212.

[0037] In this embodiment, by optimizing the local structure of the elastic hook 21, the strength of key stress areas is enhanced while ensuring the overall elasticity of the elastic hook 21. The design of the root 211 being thicker than the hook body 212 allows the root 211 to have higher bending strength due to its increased cross-sectional size when subjected to pull-out force, avoiding the risk of fracture caused by stress concentration. The cantilever beam-shaped hook body 212 structure allows for controllable elastic deformation during assembly through the deformation capability of its specific geometry. At the same time, the thickness difference between the root 211 and the hook body 212 creates a stiffness gradient, maintaining the elastic deformation space required for engagement while suppressing plastic deformation through the increased thickness of the root 211. The combination of these two aspects achieves a balance between elasticity and strength of the elastic hook 21 under repeated stress conditions, solving the problem of vulnerability of the root 211 caused by the size reduction of the elastic hook 21.

[0038] In a preferred embodiment, the engaging end of the buckle 11 is provided with a rounded corner structure. By providing a rounded corner structure at the engaging end of the buckle 11, the defects of right angles or sharp corners in traditional buckles 11 are eliminated. The rounded corner structure can effectively reduce local stress concentration when the buckle 11 contacts the elastic hook 21, avoiding material fatigue or fracture caused by stress concentration; at the same time, the rounded corner structure can guide the elastic hook 21 to slide more smoothly into the buckle 11 during assembly, reducing the risk of plastic deformation caused by hard impact. This design not only improves the mechanical strength of the mating interface between the buckle 11 and the elastic hook 21, but also prevents abnormal force components caused by minor misalignment or deformation by optimizing the geometry of the contact surface, thereby maintaining the stability of the engaging structure.

[0039] In a preferred embodiment, the buckle 11 has a guide ramp 111 for guiding the elastic hook 21 to slide in. By providing the guide ramp 111 on the buckle 11, the ramp structure can guide the sliding path of the elastic hook 21 during assembly. The inclination angle and surface morphology of the guide ramp 111 are specially designed so that when the elastic hook 21 of the plastic connector 2 is axially pressed into the metal part 1, its hook body 212 forms a progressive fit with the contact surface of the buckle 11. This structure eliminates the stress concentration points that may be generated at the edge of the traditional right-angle buckle 11, and converts the lateral component force on the elastic hook 21 during deformation into a normal force along the ramp, thereby reducing the risk of plastic deformation of the root 211 of the elastic hook 21. The guiding effect of the guide ramp 111 can also compensate for the misalignment deviation caused by the machining tolerance of the parts, ensuring that multiple elastic hooks 21 can slide into the corresponding buckle 11 positions synchronously and smoothly, avoiding uneven assembly stress caused by local jamming.

[0040] In a preferred embodiment, a sealing ring 4 is provided between the connecting ends of the metal part 1 and the plastic connector 2, and the sealing ring 4 is in close contact with the guide slope 111.

[0041] In this embodiment, by adding a sealing ring 4 at the connection end between the metal part 1 and the plastic connector 2, and tightly abutting the sealing ring 4 against the guide slope 111 of the buckle 11, this design achieves a dual technical effect. First, the sealing ring 4 directly abutting the guide slope 111 effectively fills the assembly gap between the metal part 1 and the plastic connector 2, eliminating the problem of discontinuity in the sealing interface caused by tolerance or deformation, thereby preventing fluid leakage from the connection end. Second, the tight abutting action of the sealing ring 4 against the guide slope 111 suppresses the outward component force generated by the guide slope 111 when under force, preventing the elastic hook 21 from slipping off along the guide slope 111 due to the component force, thus maintaining the stable engagement state of the buckle 11 and the elastic hook 21. In addition, the sealing ring 4 is located at the connection end between the metal part 1 and the plastic connector 2, directly covering the mating area of ​​the buckle 11 and the elastic hook 21, compensating for gap changes caused by elastic deformation during dynamic rotation, further improving the durability of the connection structure.

[0042] In a preferred embodiment, the sealing ring 4 has a lip-shaped cross-section. By designing the sealing ring 4 with a lip-shaped cross-section, its unique geometric characteristics enhance the sealing performance. When subjected to axial pressure, the lip-shaped sealing ring 4 can undergo radial expansion deformation, thereby more tightly fitting the guide slope 111 and inner wall surface of the metal part 1. This structure is particularly suitable for conditions with assembly tolerances or component deformation: when a slight displacement occurs between the metal part 1 and the plastic connector 2 due to force, the lip-shaped sealing ring 4 can continuously compensate for the gap change through its own elastic deformation, preventing the sealing interface from detaching. Furthermore, compared to the traditional rectangular cross-section sealing ring 4, the tip contact form of the lip-shaped structure effectively reduces the frictional resistance of the contact surface, maintaining the sealing effect during rotational motion while reducing wear of the sealing ring 4 due to friction.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and alterations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A highly durable rotary joint, comprising a sleeve-shaped metal part (1) and a plastic connector (2) that mates with the metal part (1), wherein the inner wall of the metal part (1) is provided with an inwardly protruding buckle (11), characterized in that, The top of the plastic connector (2) has N elastic hooks (21) that are adapted to the buckle (11) in a circumferential direction, where 2≤N≤4. After assembly, there is an axial gap (3) between the engagement surface of the elastic hook (21) and the engagement surface of the buckle (11). The axial gap (3) is configured to provide space for deformation when the elastic hook (21) undergoes elastic deformation, so as to maintain the effective engagement state between the elastic hook (21) and the buckle (11) and prevent the connection from loosening.

2. The highly durable rotary joint according to claim 1, characterized in that, The N elastic hooks (21) are circumferentially distributed at equal intervals.

3. The highly durable rotary joint according to claim 1, characterized in that, The axial clearance (3) has a size range of 0.5mm-0.8mm.

4. The highly durable rotary joint according to claim 1, characterized in that, The axial gap (3) is configured such that after the elastic hook (21) undergoes elastic deformation within the expected range, the size of the axial gap (3) decreases, but the preset gap is still maintained.

5. The highly durable rotary joint according to any one of claims 1-4, characterized in that, The number of elastic hooks (21) is 4.

6. The highly durable rotary joint according to claim 5, characterized in that, The elastic hook (21) includes a root (211) and a cantilever-beam-shaped hook body (212), wherein the thickness of the root (211) is greater than the thickness of the hook body (212).

7. The highly durable rotary joint according to claim 1, characterized in that, The engaging end of the buckle (11) has a rounded corner structure.

8. The highly durable rotary joint according to claim 1, characterized in that, The buckle (11) has an inlet ramp (111) for guiding the elastic hook (21) to slide in.

9. The highly durable rotary joint according to claim 8, characterized in that, A sealing ring (4) is also provided between the connection end of the metal part (1) and the plastic connector (2), and the sealing ring (4) is in close contact with the guide slope (111).

10. The highly durable rotary joint according to claim 9, characterized in that, The sealing ring (4) has a lip-shaped cross-section.

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