Needle bearing swing check valve

Abstract

The application discloses a needle bearing rotary check valve and relates to the technical field of check valves.The needle bearing rotary check valve comprises a valve body, a valve cover connected with the valve body through bolts, a pin shaft, a rocker arm, a valve clack, a bearing fixing frame and a valve seat, the bearing fixing frame is provided with a supporting part, and the outer surface of the supporting part is provided with a locking part.The device is provided with an independent bearing fixing frame outside the valve body, and the whole set of needle bearings (including an inner ring, needle pieces and an outer ring) are integrated in the bearing fixing frame to form an external and modular rotary bearing assembly.The design is different in that the professional needle bearings are responsible for the functions of bearing main radial load and rotary motion, the pure rolling of the internal needle pieces is used to replace the traditional sliding friction, and thus the problems of large opening and closing resistance, high starting pressure difference and early wear caused by sliding friction are eliminated.Meanwhile, the functions of the wear-resistant bushing and the sealing assembly located at the penetration of the valve body have been essentially changed.

Description

Technical Field

[0001] This invention relates to the field of check valve technology, and more specifically to a needle roller bearing swing check valve. Background Technology

[0002] Swing check valves are key components in fluid pipeline systems. Their core function is to achieve unidirectional shut-off by relying on the weight of the valve disc and the reverse pressure of the medium, preventing backflow. The valve disc is hinged to a rocker arm and a pin, which is supported at both ends on the valve body. The flexibility of its rotation and the durability of the support structure directly determine the valve's opening and closing performance, sealing reliability, and service life.

[0003] Traditional swing check valves generally employ a sliding friction pair consisting of a pin and a bushing or liner directly embedded in the valve body's shaft hole. This structure has certain drawbacks in actual operation: during the opening and closing process, continuous metal-to-metal sliding friction occurs between the pin and the bushing, easily generating significant swing resistance. This results in a higher starting pressure differential required for valve opening and closing, sluggish response, and inevitably causes surface wear, reducing the valve's opening and closing sensitivity.

[0004] Furthermore, as operating time accumulates, the wear gaps continue to widen, which can lead to internal leakage due to poor sealing. If the wear exceeds the tolerance, it is often necessary to carry out complex repairs or complete replacement of the valve body, resulting in extremely high maintenance costs and a large workload.

[0005] In summary, a needle roller bearing swing check valve needs to be developed to solve the above problems. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a needle roller bearing swing check valve, comprising: a valve body, a valve cover, a pin, a rocker arm, a valve disc, a bearing bracket, and a valve seat, all bolted to the valve body. The valve body and valve cover constitute the main pressure-bearing and flow channel structure of the valve. The pin, also called a trunnion, connects the valve disc and the rocker arm and transmits rotational motion. The rocker arm is a lever component that transmits fluid thrust to the valve disc and is fixedly connected to the pin. The valve disc is a disc-shaped seal, one side of which seals against the valve seat and is pushed by fluid pressure to open and close the valve. A support component is mounted on the bearing bracket, and a locking component is provided on the outer surface of the support component. The bearing bracket is a boss structure integrally cast and fixed to the valve body, providing external installation and protection space for the needle roller bearing and facilitating disassembly and maintenance. The auxiliary mechanism includes: The support component includes an inner ring, needle rollers, and an outer ring. The inner ring, needle rollers, and outer ring together constitute a standard needle roller bearing. The needle rollers include precision needle rollers and a cage, which is existing technology. The inner ring is a component that is fixed to the pin and rotates synchronously. The outer ring is a component that is fixed in the bearing holder and does not rotate. The needle rollers roll between the raceways of the inner and outer rings to greatly reduce friction. The outer surface of the outer ring is provided with a limiting bracket, which is a retaining ring fixed to the inner surface of the bearing holder to limit the axial sliding position of the entire needle roller bearing and achieve axial positioning. The locking component includes a rotating cover, which is a removable cover plate fixed to the outside of the bearing bracket by a threaded connection for sealing and protecting the internal bearing. The outer surface of the rotating cover has a threaded groove at the edge near the bearing bracket. A rubber ring is fixedly connected to the inner surface of the rotating cover. The rubber ring is a ring-shaped pad made of elastic rubber. When the rotating cover is tightened, the rubber ring is compressed and tightly fits against the outer side of the bearing outer ring, providing axial preload and preventing the bearing outer ring from rotating. The axial fitting pressure here is greater than the fluid thrust of water flow on the valve disc when the valve is opened. At the same time, the material of the rubber ring can prevent the metal cover from directly pressing on the bearing and causing wear.

[0007] Furthermore, the pin passes through the interior of the bearing bracket in sequence, and a lip seal and an anti-wear bushing are sequentially fitted on the through portion near the valve disc. The inner lip of the lip seal is in interference contact with the pin to form a rotary seal. The lip seal is a dynamic seal installed on the inner end of the anti-wear bushing, with its inner lip in interference contact with the pin to prevent media leakage. It is made of fluororubber and generates a controllable low-friction sliding seal when the pin rotates. An O-ring is installed in the outer circumferential groove of the anti-wear bushing. The anti-wear bushing is a bushing made of wear-resistant engineering parts and is press-fitted into the through hole of the bearing bracket. The O-ring is a seal installed in the outer circumferential groove of the anti-wear bushing to achieve a static seal between the anti-wear bushing and the through hole of the bearing bracket.

[0008] Furthermore, the side of the limiting bracket near the rotating cover is fixedly connected to the inner surface of the bearing fixing bracket, and the rotating cover is connected to the inner surface of the bearing fixing bracket by the thread on its outer surface. That is, the bearing fixing bracket has an internal thread at the corresponding position on the inner side, which cooperates with the external thread of the rotating cover to realize the detachable fixing of the locking component.

[0009] Furthermore, the lip seal is installed on the inner surface of the wear-resistant bushing, the outer surface of the wear-resistant bushing is interference-fitted with the perforation of the bearing bracket, and the O-ring seal is sealingly fitted with the inner wall of the bearing bracket. This structure forms a double sealing barrier: the lip seal acts as a dynamic primary seal to block the medium, and the O-ring seal acts as a static auxiliary seal to prevent the medium from seeping out along the mating gap.

[0010] Furthermore, the locking component also includes a bend, which is a pipe fixed in the internal cavity of the pin and provides sliding guidance for the insertion rod. An alignment hole is provided at the bottom of the bend, and an insertion rod is slidably connected inside the bend. The insertion rod is a locking pin that can slide inside the bend, and its lower end can extend out of the outer surface of the pin and be inserted into the alignment hole of the inner ring, for fixing the pin and the inner ring of the needle roller bearing.

[0011] Furthermore, a compression spring is fixedly connected to the top of the insertion rod. The compression spring is a helical spring that provides bias force to the insertion rod toward the locking position (i.e., downward insertion into the alignment hole). A limit tube is fixedly connected to the top of the compression spring. The limit tube is a tubular component fixed inside the bend to limit the spring compression stroke and to guide the rigid pull rope.

[0012] Furthermore, a rigid pull rope is slidably connected to the inner wall of the limiting tube. The rigid pull rope is a traction rope made of high-strength polymer and is used to connect the insertion rod and the external pull ring. One end of the rigid pull rope is fixedly connected to a pull ring, which is a handle for the operator to manually pull to release the locked state.

[0013] Furthermore, the alignment hole is formed on the outer surface of the inner ring. The alignment hole is a through hole machined on the outer cylindrical surface of the inner ring of the needle roller bearing. The size of the insertion rod is adapted to the size of the alignment hole to ensure that the insertion rod can be smoothly inserted and transmit torque.

[0014] Furthermore, the outer surface of the limiting tube is fixedly connected to the inner wall of the bent tube.

[0015] Furthermore, the bottom end of the rigid pull rope is fixedly connected to the top of the insertion rod.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This device features an independent bearing bracket on the outside of the valve body, integrating the entire needle roller bearing assembly (including the inner ring, needle rollers, and outer ring) into a single external, modular rotary support assembly. The key difference in this design is that the primary radial load and rotational motion are entirely handled by the specialized needle roller bearing. The pure rolling motion of the internal needle rollers replaces traditional sliding friction, eliminating the problems of high opening and closing resistance, high starting pressure differential, and premature wear caused by sliding friction. Simultaneously, the anti-wear bushing and sealing assembly located at the valve body penetration point undergo a fundamental functional transformation. They no longer serve as the primary rotating load-bearing components but instead work in conjunction with the needle roller bearing: the needle roller bearing is placed in a dry environment outside the valve body, avoiding direct contact with the fluid medium inside the pipeline, thus greatly reducing corrosion and contamination damage; while the anti-wear bushing assembly focuses on achieving reliable static and dynamic seals. Even if the seals wear after long-term operation, only this low-cost standard sealing assembly needs to be replaced, without damaging the valve body or the high-value needle roller bearing. This collaborative design, which uses an external bearing to handle movement and an internal bushing for sealing, ensures valve sensitivity and long service life while achieving controllable wear and economical maintenance.

[0017] 2. This device incorporates a combined anti-wear sealing assembly consisting of an anti-wear bushing, a lip seal, and an O-ring at the critical point where the pin penetrates the valve body. This assembly solves the sealing problem of media leakage along the rotating pin axis and the wear problem caused by direct contact between the pin and the valve body (or bearing bracket). The lip seal provides dynamic rotational sealing; the O-ring provides static interface sealing. This invention avoids media leakage caused by gaps created by single seal failure or metal wear, while also preventing wear on the valve body structure, reducing the maintenance scope to standard seals that can be quickly replaced.

[0018] 3. This device achieves reliable axial clamping and protection of the outer ring of the needle roller bearing through a threaded rotating cover and an internal rubber ring. This structure solves the problem of potential axial movement or accidental rotation of external bearings under the action of fluid axial force, and eliminates the need to disassemble the valve interior for bearing inspection and maintenance. The entire bearing is directly exposed by removing the rotating cover. This invention avoids abnormal wear caused by insecure bearing fixing, and overcomes the cumbersome procedures of disassembling pipes, valve covers, and even valve discs required for traditional internal bearing maintenance, minimizing maintenance workload.

[0019] 4. This device integrates a spring-driven pin (insertion rod) and an external pull ring-operated locking mechanism inside the pin shaft. By engaging with the alignment hole on the inner ring of the bearing, circumferential fixation is achieved. This mechanism solves the connection problem between the pin shaft and the bearing inner ring, which requires both torque transmission and easy disassembly. Traditional interference fits or key connections require precision machining and pressure assembly, making on-site replacement difficult. This invention avoids the need for special tools when replacing bearings, enabling rapid on-site maintenance by simply pulling the pull ring to unlock and directly replace the bearing, significantly reducing the skill requirements and tool dependence of maintenance personnel. Attached Figure Description

[0020] Figure 1 This is the front view of the present invention; Figure 2 This is a cross-sectional view of the valve body of the present invention; Figure 3 This is a schematic diagram of the pin structure of the present invention; Figure 4 This is a schematic diagram of the bearing mounting bracket of the present invention; Figure 5 This is a schematic diagram of the structure of the support component of the present invention; Figure 6 This is a schematic diagram of the structure of the wear-resistant bushing of the present invention; Figure 7 This is a cross-sectional view of the rotating cover of the present invention; Figure 8 This is a cross-sectional view of the pin shaft of the present invention; Figure 9 This is a cross-sectional view of the bend in the present invention.

[0021] In the diagram: 1. Valve body; 2. Valve cover; 3. Pin; 4. Rocker arm; 5. Valve disc; 61. Support component; 611. Inner ring; 612. Needle roller; 613. Outer ring; 614. Limiting bracket; 615. Lip seal; 616. Anti-wear bushing; 617. O-ring seal; 62. Locking component; 621. Rotating cover; 622. Threaded groove; 623. Rubber ring; 624. Bend; 625. Alignment hole; 626. Insertion rod; 627. Compression spring; 628. Limiting tube; 629. Rigid pull rope; 630. Pull ring; 7. Bearing retainer; 8. Valve seat. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0023] For the first embodiment, please refer to... Figures 1-7 This invention relates to a needle roller bearing swing check valve, comprising: a valve body 1, a valve cover 2, a pin 3, a rocker arm 4, a valve disc 5, a bearing mounting bracket 7, and a valve seat 8, all bolted to the valve body 1. The valve body 1 and valve cover 2 constitute the main pressure-bearing and flow channel structure of the valve. The pin 3, also called a trunnion, connects the valve disc 5 to the rocker arm 4 and transmits rotational motion. The rocker arm 4 is a lever component that transmits fluid thrust to the valve disc 5 and is fixedly connected to the pin 3. The valve disc 5 is a disc-shaped seal, one side of which seals against the valve seat 8 and is pushed by fluid pressure to open and close the valve. A support component 61 is mounted on the bearing mounting bracket 7, and a locking component 62 is provided on the outer surface of the support component 61. The bearing mounting bracket 7 is a boss structure integrally cast and fixed to the valve body 1, providing external installation and protection space for the needle roller bearing and facilitating disassembly and maintenance. The auxiliary mechanism 6 includes: The support component 61 includes an inner ring 611, needle rollers 612, and an outer ring 613. The inner ring 611, needle rollers 612, and outer ring 613 together constitute a standard needle roller bearing. The needle rollers 612 include precision needle rollers and a cage, which is prior art. The inner ring 611 is a component that is fixed to the pin 3 and rotates synchronously. The outer ring 613 is a component that is fixed in the bearing retainer 7 and does not rotate. The needle rollers 612 are components that roll between the raceways of the inner and outer rings 613 to greatly reduce friction. The outer surface of the outer ring 613 is provided with a limiting bracket 614, which is a retaining ring fixed to the inner surface of the bearing retainer 7 to limit the axial sliding position of the entire needle roller bearing and achieve axial positioning. The locking component 62 includes a rotating cover 621, which is a removable cover plate fixed to the outside of the bearing bracket 7 by a threaded connection for sealing and protecting the internal bearing. The outer surface of the rotating cover 621 has a threaded groove 622 at the edge near the bearing bracket 7. A rubber ring 623 is fixedly connected to the inner surface of the rotating cover 621. The rubber ring 623 is an annular pad made of elastic rubber. When the rotating cover 621 is tightened, the rubber ring 623 is compressed and tightly fits against the outside of the bearing outer ring 613, providing axial preload and preventing the bearing outer ring 613 from rotating. The axial fitting pressure here is greater than the fluid thrust of the water flow on the valve disc 5 when the valve is opened. At the same time, the material of the rubber ring 623 can prevent the metal cover from directly pressing on the bearing and causing wear.

[0024] The pin 3 passes through the interior of the bearing retainer 7 in sequence, and the part of the pin 3 that passes through the bearing retainer 7 near the valve disc 5 is fitted with a lip seal 615 and an anti-wear bushing 616 in sequence. The inner lip of the lip seal 615 is in interference contact with the pin 3 to form a rotary seal. The lip seal 615 is a dynamic seal installed on the inner end of the anti-wear bushing 616, and its inner lip is in interference contact with the pin 3 to prevent media leakage. It is made of fluororubber and generates a controllable low-friction sliding seal when the pin 3 rotates. An O-ring 617 is installed in the outer circumferential groove of the anti-wear bushing 616. The anti-wear bushing 616 is a bushing made of wear-resistant engineering parts and is press-fitted into the through hole of the bearing retainer 7. The O-ring 617 is a seal installed in the outer circumferential groove of the anti-wear bushing 616 to achieve a static seal between the anti-wear bushing 616 and the through hole of the bearing retainer 7.

[0025] The side of the limiting bracket 614 near the rotating cover 621 is fixed to the inner surface of the bearing fixing bracket 7. The rotating cover 621 is connected to the inner surface of the bearing fixing bracket 7 by the thread on its outer surface. That is, the bearing fixing bracket 7 has an internal thread at the corresponding position on the inner side, which cooperates with the external thread of the rotating cover 621 to realize the detachable fixing of the locking component 62.

[0026] A lip seal 615 is installed on the inner surface of the wear-resistant bushing 616. The outer surface of the wear-resistant bushing 616 is interference-fitted with the through hole of the bearing bracket 7. An O-ring seal 617 is sealed with the inner wall of the bearing bracket 7. This structure forms a double sealing barrier: the lip seal 615 acts as a dynamic primary seal to block the medium, while the O-ring seal 617 acts as a static auxiliary seal to prevent the medium from seeping out along the mating gap.

[0027] The specific work process is as follows: When the fluid in the pipeline flows in the forward direction (i.e., the medium flows from below the valve disc 5 towards the sealing surface of the valve seat 8), its working principle is as follows: First, fluid pressure acts on the back side (i.e., the non-sealing surface) of valve disc 5, generating an upward thrust on valve disc 5. This thrust is transmitted entirely to rocker arm 4 through the rigid connection between valve disc 5 and rocker arm 4. Since the other end of rocker arm 4 is fixedly connected to pin 3, this thrust is converted into a torque that drives pin 3 to rotate.

[0028] Next, pin 3 begins to rotate under the action of rotational torque. Pin 3 is fixedly connected to the inner ring 611 of the needle roller bearing, so pin 3 directly drives the inner ring 611 to rotate synchronously. At this time, the inner raceway of the inner ring 611 contacts the needle rollers, driving countless tiny cylindrical needle rollers to rotate on their own axis and roll on the raceway between the inner ring 611 and the stationary outer ring 613. This process completely transforms the direct metal-to-metal sliding friction at the sleeve of the traditional check valve disc 5 into low-resistance rolling friction between the needle rollers and the raceway. The outer ring 613 is pressed into the inner hole of the bearing retainer 7 and is axially positioned by the limiting bracket 614, thus remaining absolutely stationary throughout the process and not rotating with the inner ring 611.

[0029] At the same time, the rotation of the pin 3 will cause the rocker arm 4 fixed thereto to swing. The rocker arm 4 will eventually push the valve disc 5 to rotate upward around the axis of the pin 3, leaving the sealing surface of the valve seat 8, thereby opening the fluid passage and allowing the medium to pass smoothly through the valve body 1.

[0030] When the fluid pressure in the pipeline decreases or a reverse flow trend occurs, the valve closing process is as follows: First, the fluid pressure acting on the front of valve disc 5 disappears or reverses. At this time, under the combined action of its own weight, part of the weight of rocker arm 4, and any possible reverse fluid pressure, valve disc 5 generates a torque that closes the valve.

[0031] Next, the closing torque is transmitted in the reverse direction to the pin 3 via the rocker arm 4. Under the action of the reverse torque, the pin 3, inner ring 611, and needle roller bearing assembly also begin to rotate in the reverse direction with extremely low rolling friction resistance. The valve disc 5 then falls downwards.

[0032] Finally, the sealing surface of valve disc 5 falls precisely back onto the sealing surface of valve seat 8, and with the assistance of the reverse pressure of the medium, they fit tightly together to form a reliable seal, completely blocking the reverse flow of the medium.

[0033] Throughout the entire opening and closing cycle, the sealing and anti-wear system, consisting of the anti-wear bushing 616, the lip seal 615, and the O-ring seal 617, works together to ensure long-term operational reliability. Its specific working mechanism is as follows: First, the anti-wear bushing 616 serves as the base and the first line of defense. This bushing is pressed into the shaft hole of the bearing retainer 7 with an interference fit, and its inner hole has a precise, small clearance fit with the pin 3. This clearance is sufficient to prevent load-bearing friction between the pin 3 and the inner hole of the bushing during rotation, thus protecting the bearing retainer 7 from damage and preventing fluid leakage.

[0034] Secondly, the lip seal 615 serves as the core dynamic sealing barrier. This seal, with its outer ring 613, is fixed within the inner wall of the anti-wear bushing 616, remaining stationary. Its built-in elastic sealing lip forms an interference fit with the outer surface of the pin 3 during assembly. When the pin 3 rotates, continuous, controlled sliding friction occurs between the sealing lip and the surface of the pin 3. This tight sliding contact effectively prevents pressurized media within the valve cavity from permeating outwards along the surface of the pin 3, achieving the crucial dynamic rotary seal. The inner ring 611 of the lip seal 615 is not a smooth cylinder but is designed with multiple elastic lips. Before installation, the inner diameter of these lips is slightly smaller than the outer diameter of the pin 3. During assembly, the pin 3 needs to be "forced" through this smaller hole, causing the lips to elastically deform and always maintain a certain pressure, tightly gripping the cylindrical surface of the pin 3 (interference fit).

[0035] When pin 3 rotates, "sliding friction" occurs between the metal surface of pin 3 and the stationary rubber lip. However, because the contact pressure is controllable and the lip material itself has self-lubricating properties, this is a controlled, low-friction sliding designed for sealing.

[0036] The O-ring 617 serves as an auxiliary static seal. This O-ring is installed within the annular groove on the outer circumference of the wear-resistant bushing 616. When the wear-resistant bushing 616 is pressed into the shaft hole of the bearing retainer 7, the O-ring is compressed and deformed, completely filling the microscopic gap between the bushing and the shaft hole wall, forming an absolutely reliable static seal between them, ensuring that no medium can leak into the external environment of the valve or into the bearing cavity.

[0037] Finally, the axial locking and protection of the rotating cover 621. The rotating cover 621 is screwed onto the outer end of the bearing retainer 7 via threads. The rubber ring 623 connected to its inner end face undergoes compression deformation when tightened, applying a constant axial preload to the end face of the outer ring 613 of the needle roller bearing. This preload is calculated to be greater than the maximum axial thrust component generated by the fluid acting on the valve disc 5, thereby ensuring that the outer ring 613 of the bearing will not experience axial movement or accidental rotation under any operating condition. At the same time, the elasticity of the rubber material avoids indentations or wear that may be caused by the direct rigid pressure of the metal end cover on the precision end face of the bearing.

[0038] In this embodiment, the key component addresses the following issues: 1. Needle roller bearing (inner ring 611, needle roller, outer ring 613): The sliding friction at the hinge of valve disc 5 is changed to rolling friction, which reduces the swing resistance and starting pressure difference of valve disc 5, making it extremely sensitive to small flow changes, allowing the sealing pair to close faster and improving the sensitivity of valve disc 5.

[0039] 2. The combination of lip seal 615 and O-ring seal 617 solves the dynamic sealing problem at the point where the pin 3 passes through the valve body 1, forming a main and auxiliary double seal, which can prevent media leakage and external contaminants from entering the bearing cavity.

[0040] 3. Anti-wear bushing 616: It solves the wear problem caused by direct contact between the pin 3 and the valve body 1 (through the bearing fixing bracket 7) and protects the main structure of the valve.

[0041] 4. Bearing mounting bracket 7 and rotating cover 621 module: This module solves the problems of external bearing installation, protection and pre-tightening. Its structure facilitates daily inspection, lubrication and overall replacement of bearings, avoiding the disadvantages of difficult maintenance of traditional built-in bearings.

[0042] For the second embodiment, please refer to... Figures 1-9 Based on Embodiment 1, the locking component 62 further includes a bent tube 624. The bent tube 624 is a pipe fixed in the internal cavity of the pin 3, providing sliding guidance for the insertion rod 626. An alignment hole 625 is provided at the lower part of the bent tube 624. The insertion rod 626 is slidably connected inside the bent tube 624. The insertion rod 626 is a locking pin that can slide inside the bent tube 624, and its lower end can extend out of the outer surface of the pin 3 and insert into the alignment hole 625 of the inner ring 611, thereby fixing the pin 3 to the inner ring 611 of the needle roller bearing. The outer surface of the bent tube 624 is fixedly connected to the inner surface of the pin 3.

[0043] A compression spring 627 is fixedly connected to the top of the insertion rod 626. The compression spring 627 is a helical spring that provides bias force to the insertion rod 626 toward the locked position (i.e., downward insertion into the alignment hole 625). A limit tube 628 is fixedly connected to the top of the compression spring 627. The limit tube 628 is a tubular component fixed inside the bend 624 to limit the spring compression stroke and to guide the rigid pull rope 629.

[0044] A rigid pull rope 629 is slidably connected to the inner wall of the limiting tube 628. The rigid pull rope 629 is a traction rope made of high-strength polymer, used to connect the insertion rod 626 and the external pull ring 630. One end of the rigid pull rope 629 is fixedly connected to the pull ring 630, which is a handle for the operator to manually pull to release the locked state.

[0045] Alignment hole 625 is formed on the outer surface of inner ring 611. Alignment hole 625 is a through hole machined on the outer cylindrical surface of inner ring 611 of needle roller bearing. The size of insertion rod 626 is adapted to the size of alignment hole 625 to ensure that insertion rod 626 can be smoothly inserted and transmit torque.

[0046] The outer surface of the limiting tube 628 is fixedly connected to the inner wall of the bent tube 624.

[0047] The bottom end of the rigid pull cord 629 is fixedly connected to the top of the insertion rod 626.

[0048] The specific work process is as follows: When a valve operates for an extended period, and its core moving component, the needle roller bearing, needs maintenance or replacement due to reaching the end of its service life or requiring additional lubrication, the locking mechanism added in this embodiment makes this process extremely simple and quick, requiring no large, specialized tools. Its specific operation is as follows: First, the operator manually unscrews and removes the rotating cover 621, which is threaded onto the outside of the bearing retainer 7, counterclockwise. This step removes the external encapsulation and axial clamping of the bearing assembly, exposing the internal needle roller bearing and the end of the pin 3.

[0049] Next, the operator hooks the pull ring 630 located on the end face of the pin 3 with their finger and smoothly applies a pulling force axially outward (i.e. away from the valve body 1). This pulling force is transmitted through the rigid pull rope 629 fixedly connected to it, which slides in the inner hole of the limiting tube 628, ensuring that the force is transmitted in a precise axial direction.

[0050] Subsequently, the pulling force acts directly on the tip of the insertion rod 626. Driven by the pulling force, the insertion rod 626 overcomes the preload of the compression spring 627 and slides upward along the inner wall of the bend 624. As the insertion rod 626 moves upward, its lower end (i.e., the locking end) gradually exits completely from the alignment hole 625 of the needle roller bearing inner ring 611. At this point, the circumferential lock between the pin 3 and the needle roller bearing inner ring 611 is completely released, leaving only a certain clearance fit between them.

[0051] Then, while keeping the pull ring 630 in the pulled-out position (i.e., ensuring that the insertion rod 626 remains retracted and does not interfere with the inner ring 611), the operator can directly pinch the outer ring 613 of the needle roller bearing by hand and easily pull it out along the pin shaft 3 axially (in the same direction as the pull ring 630). At this point, the old, replacement, or maintenance-required needle roller bearing assembly has been safely and completely removed.

[0052] Before installing a new or maintained needle roller bearing, the operator must ensure that the pull ring 630 is still pulled out and the insert rod 626 remains retracted under tension. This is crucial to ensure that the new bearing can be smoothly fitted into the pin 3 without colliding or interfering with the extended insert rod 626.

[0053] First, remove the new needle roller bearing from its packaging, and if necessary, add an appropriate amount of long-life grease to its raceway. Then, align the bearing bore with the end of the pin 3 and push it smoothly inward axially (i.e., toward the valve body 1). The bearing assembly (including the inner ring 611, needle rollers, cage, and outer ring 613) slides along the outer surface of the pin 3 into the mounting cavity of the bearing retainer 7 until the end face of the outer ring 613 is in close contact with the retaining bracket 614 inside the retainer. This contact indicates that the bearing has reached the precise axial working position specified in the design.

[0054] The second step involves the operator slowly releasing the pull ring 630 after confirming that the bearing has been pushed into place. At this point, the preload of the compression spring 627 is released, and its restoring force pushes the insertion rod 626 downwards (towards the outside of the pin 3). The bottom end of the insertion rod 626 has a rounded rubber tip, a design intended to protect the delicate inner ring 611 surface and reduce friction.

[0055] At this point, two situations may occur: Scenario A (Ideal Alignment): If, during the pushing of the bearing, the alignment hole 625 on its inner ring 611 rotates precisely to the position completely aligned with the outlet of the insertion rod 626 on the pin 3, then at the instant the pull ring 630 is released and the spring force is released, the insertion rod 626, guided by its bottom rubber round head, will quickly and accurately fall completely into the alignment hole 625 with a "click." Simultaneously, the pull ring 630, connected to the insertion rod 626 via the rigid pull rope 629, will also move inward (closer to the port of the bend 624) until it is flush against the end face of the bend 624. This clear visual and audible signal intuitively indicates to the operator that locking has been completed.

[0056] Scenario B (requiring fine-tuning): More commonly, after the initial push, the alignment hole 625 is not aligned with the insertion rod 626. In this case, after releasing the pull ring 630, the rubber round head at the bottom of the insertion rod 626 will extend downward under the spring force and fit tightly against the smooth outer surface of the inner ring 611 of the needle roller bearing. Due to the presence of the rubber round head, even if it is necessary to rotate the inner ring 611 to find the alignment hole 625, the round head of the insertion rod 626 and the surface of the inner ring 611 will have a flexible contact, avoiding direct metal-to-metal scraping damage to the precision surface of the inner ring 611. If rotating the inner ring 611 is troublesome, one hand can keep the pull ring 630 in place while the other hand rotates the needle roller bearing to slowly adjust it until the final insertion rod 626 is aligned with the alignment hole 625.

[0057] Once the inner ring 611 rotates to a specific angle, the alignment hole 625 on it moves directly below the insertion rod 626. The insertion rod 626, which has been accumulating spring force, moves downward, causing its rounded end to fall into the interior of the hole. Driven by the continuous spring force, it springs fully into the alignment hole 625, completing the locking process. Similarly, the pull ring 630 will synchronously return to the port of the bend 624, providing a clear indication that the locking is complete.

[0058] Regardless of which method is used to lock the bearing, after confirming that the insertion rod 626 is inserted and the pull ring 630 has returned to its original position, the operator can proceed with the final assembly: align the rubber ring 623 on the inner side of the rotating cover 621 with the end face of the bearing outer ring 613, and then screw the rotating cover 621 clockwise into the threads of the bearing retainer 7 and tighten it. The rotating cover 621, through the rubber ring 623, applies a stable axial preload to the entire needle roller bearing assembly, ensuring no movement during operation, no rotation of the outer ring 613, and isolation from external contamination. At this point, the entire replacement and installation process for the needle roller bearing is complete, and the valve can be immediately restored to use.

[0059] Finally, the following should be added regarding this device: After a long period of operation, the lip seal 615, as a dynamic seal, may experience a marginal decrease in sealing performance due to normal aging and wear. At this point, the modular design of this device allows for further in-depth maintenance. Its core principle is to control potential wear damage to low-cost replaceable parts, thereby avoiding irreversible damage to the main pressure-bearing components such as the valve body 1 or bearing bracket 7. Specifically, the maintenance work of replacing the anti-wear bushing 616, lip seal 615, and O-ring 617 must be carried out under safe conditions—with the valve completely offline, no medium flowing in the pipeline, and no pressure—following the following steps: First, following the disassembly steps of the second embodiment described above, the operator unscrews the rotating cover 621 in sequence, pulls the pull ring 630 to release the locking mechanism, and removes the entire needle roller bearing assembly from the pin 3. At this time, the internal mounting cavity of the bearing retainer 7 is completely exposed.

[0060] Next, the operator used a screwdriver to unscrew several fastening screws that secured the retaining bracket 614 on the bearing mounting bracket 7. After removing the retaining bracket 614, the end of the anti-wear bushing 616, which was originally hidden inside, became clearly visible.

[0061] Subsequently, the exposed end of the anti-wear bushing 616 is firmly gripped by the jaws of a specialized pulling tool (such as pliers or a small hydraulic puller). A steady axial pulling force is applied using the tool to pull the original anti-wear bushing 616 out of its interference fit with the bearing retainer 7 shaft hole. Once the bushing is removed, the lip seal 615 installed at its inner end and the O-ring seal 617 in its outer circumferential groove are also pulled out.

[0062] Then, the removed old components are disposed of. A brand new wear-resistant bushing 616, a lip seal 615 pre-installed in its inner groove, and an O-ring 617 pressed into its outer circumferential groove are assembled as a ready component assembly. After applying a small amount of grease to the outer surface of the new wear-resistant bushing 616 and the inner surface of the lip seal 615, an installation tool is used to smoothly press it axially into the shaft hole of the bearing retainer 7 until the designed depth is reached.

[0063] After completing the above replacement, restore the installation in the reverse order: first, put the limit bracket 614 back in its original position and tighten it with screws; then, according to the installation steps of the second embodiment, install the needle roller bearing and ensure that the insertion rod 626 is locked with the alignment hole 625; finally, tighten the rotating cover 621.

[0064] This maintenance process highlights another core advantage of this device: it successfully shifts the potential wear path endpoint from the non-replaceable and costly valve body 1 main structure to specially designed, independently replaceable, low-cost sealing and anti-wear components. Through this standardized process, even if seal replacement is necessary, only standard parts are involved, eliminating the need to replace the entire valve or perform complex on-site machining, thereby significantly reducing maintenance costs and downtime throughout the equipment's lifecycle.

[0065] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A needle roller bearing swing check valve, comprising: The valve body (1), valve cover (2), pin (3), rocker arm (4), valve disc (5), bearing bracket (7), and valve seat (8) are bolted to the valve body (1), characterized in that: a support component (61) is installed on the bearing bracket (7), and a locking component (62) is provided on the outer surface of the support component (61). The support component (61) includes an inner ring (611), a needle roller (612) and an outer ring (613), and the outer surface of the outer ring (613) is provided with a limiting frame (614). The locking component (62) includes a rotating cover (621), on the outer surface of the rotating cover (621) near the edge of the bearing fixing bracket (7) a threaded groove (622) is provided, and a rubber ring (623) is fixedly connected to the inner surface of the rotating cover (621).

2. The needle roller bearing swing check valve according to claim 1, characterized in that: The pin (3) passes through the interior of the bearing bracket (7) in sequence, and the part of the pin that passes through the bearing bracket (7) near the valve disc (5) is fitted with a lip seal (615) and an anti-wear bushing (616) in sequence. The inner lip of the lip seal (615) is in interference contact with the pin (3) to form a rotary seal. An O-ring (617) is installed in the outer circumferential groove of the anti-wear bushing (616).

3. The needle roller bearing swing check valve according to claim 1, characterized in that: The limiting bracket (614) is fixed to the inner surface of the bearing fixing bracket (7) on the side near the rotating cover (621), and the rotating cover (621) is threaded to the inner surface of the bearing fixing bracket (7) through the thread on its outer surface.

4. The needle roller bearing swing check valve according to claim 2, characterized in that: The lip seal (615) is installed on the inner surface of the wear-resistant bushing (616), the outer surface of the wear-resistant bushing (616) is interference-fitted with the through hole of the bearing bracket (7), and the O-ring seal (617) is sealed with the inner wall of the bearing bracket (7).

5. The needle roller bearing swing check valve according to claim 1, characterized in that: The locking component (62) also includes a bend (624), with an alignment hole (625) provided below the bend (624), and an insertion rod (626) slidably connected inside the bend (624).

6. The needle roller bearing swing check valve according to claim 5, characterized in that: A compression spring (627) is fixedly connected to the top of the insertion rod (626), and a limit tube (628) is fixedly connected to the top of the compression spring (627).

7. The needle roller bearing swing check valve according to claim 6, characterized in that: The inner wall of the limiting tube (628) is slidably connected to a rigid pull rope (629), and one end of the rigid pull rope (629) is fixedly connected to a pull ring (630).

8. The needle roller bearing swing check valve according to claim 5, characterized in that: The alignment hole (625) is formed on the outer surface of the inner ring (611), and the size of the insertion rod (626) is adapted to the size of the alignment hole (625).

9. The needle roller bearing swing check valve according to claim 6, characterized in that: The outer surface of the limiting tube (628) is fixedly connected to the inner wall of the bend (624).

10. The needle roller bearing swing check valve according to claim 7, characterized in that: The bottom end of the rigid pull rope (629) is fixedly connected to the top of the insertion rod (626).

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