Antifouling sealed piston rod

Abstract

The utility model discloses a kind of antifouling sealing type piston rods, comprising: piston rod, cover plate and closed sleeve;Piston rod middle part outer periphery is provided with integrally formed convex ring, cover plate is used to be fixed with external cylinder body and underside is provided with integrally formed convex ring, cover plate is opened and is passed through the central hole of piston rod;Closed sleeve is capsular structure and is sleeved in the outer periphery of piston rod, its upper and lower end is respectively equipped with connecting ring, upper end connecting ring and the convex ring of piston rod are adaptively connected and fixed, lower end connecting ring and the convex ring of cover plate are adaptively connected and fixed, the capsular structure of closed sleeve is made of telescopic material, the utility model has the advantages that service life is long, maintenance efficiency is high, sealing is durable, and adaptation range is wide, suitable for oil cylinder, air cylinder and other equipment.

Description

Technical Field

[0001] This invention relates to the field of hydraulic machinery parts technology, specifically to a contamination-proof and sealing piston rod for hydraulic cylinders. Background Technology

[0002] As a core moving component of hydraulic equipment, the piston rod's anti-fouling and sealing performance directly determines the equipment's operational stability and service life. In existing technologies, to address the piston rod's sealing problem, a sealing structure for the piston rod was proposed in application number CN202121058584.X. Its core design involves fixing a first fixing block and a second fixing block at the middle and one end of the piston rod, respectively. The two fixing blocks are correspondingly connected to a first connecting block and a second connecting block, and a corrugated rubber tube is installed between the connecting blocks to achieve a sealed protection. However, this structure has obvious flaws, as follows: Stress concentration at the connection point makes it prone to damage: The two ends of the corrugated rubber hose are rigidly fixed to the connecting block without an elastic buffer structure. When the piston rod reciprocates, the tensile / compressive stress of the rubber hose is concentrated at the connection node. Long-term use will easily cause cracking and breakage, resulting in loss of sealing function. Maintenance and disassembly are cumbersome: The fixing block and the connecting block are rigidly connected by bolts. When replacing the aging corrugated rubber tube, all connecting parts need to be disassembled, which is complicated and time-consuming. Sealing performance is easily degraded: The corrugated rubber hose relies solely on its own structure for protection, without any auxiliary sealing design. After long-term exposure, it is prone to aging and hardening, which increases the gap between it and the piston rod, allowing dust to easily penetrate. Poor structural adaptability: The fixing block and piston rod are fixed as one piece, making it impossible to flexibly adjust the position of the sealing component according to different cylinder sizes, thus limiting the applicable scenarios. To address the aforementioned shortcomings, there is an urgent need for a piston rod anti-fouling sealing structure that can solve stress concentration, simplify maintenance, improve sealing durability, and has strong adaptability. Summary of the Invention

[0003] To overcome the above-mentioned defects, this utility model provides a contamination-proof and sealing piston rod, comprising: The piston rod has an integrally formed piston rod protrusion ring on its outer periphery. The cover plate is used to fix it to the external cylinder body. It has an integrally formed cover plate protrusion on its lower side and a central hole for the piston rod to pass through. The closed sleeve is a bladder-like structure fitted around the piston rod, with connecting rings at its upper and lower ends. The upper connecting ring is fitted and fixed to the piston rod protrusion ring, and the lower connecting ring is fitted and fixed to the cover plate protrusion ring. The bladder-like structure of the closed sleeve is made of a stretchable material. Furthermore, the connection method between the connecting ring and the two protruding rings is either bolt connection or screw-in connection; when bolted, the connecting ring and the corresponding protruding ring have matching bolt holes; when screwed in, the inner wall of the connecting ring and the outer circumference of the corresponding protruding ring have matching threads. Furthermore, the expandable material of the closure sleeve is elastic rubber, and the wall thickness of the bladder-like structure is 1.5-2.5mm, fitting the outer periphery of the piston rod in its natural state. Furthermore, when the cover plate is fixed to the external cylinder, the outer periphery of the cover plate is provided with an annular mounting part, and the annular mounting part has at least 3 evenly distributed mounting holes for connecting to the external cylinder by bolts. Furthermore, it also includes a sealing ring. An annular sealing groove is provided on the inner wall of the central hole of the cover plate. The sealing ring is embedded in the annular sealing groove, and the inner ring of the sealing ring is in contact with the outer circumferential surface of the piston rod. The beneficial effects of this utility model are as follows: Solving the stress concentration problem: The expandable bladder-shaped closed sleeve replaces the rigid corrugated rubber tube, which buffers the expansion and contraction stress through the deformation of the elastic material, avoids cracking of the connection node, and significantly extends the service life; Simplified maintenance: The connecting ring and the convex ring are connected by bolts or screws, and the sealing sleeve can be replaced without disassembling the entire structure, improving maintenance efficiency by more than 60%. Improved sealing durability: The elastic rubber sealing sleeve fits the piston rod in its natural state, forming a double seal with the sealing ring of the cover plate, effectively preventing dust from penetrating and reducing the rate of seal performance degradation by 50%; Enhanced adaptability: The cover plate can be flexibly connected to cylinders of different sizes through the annular mounting part, without the need to adjust the piston rod body structure, making it applicable to a wider range of scenarios. Attached Figure Description

[0004] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0005] Figure 1 : A three-dimensional view of this utility model.

[0006] Figure 2 Front view of this utility model.

[0007] In the diagram: 1-piston rod, 11-piston rod protrusion ring, 2-sealing sleeve, 21-connecting ring, 3-cover plate, 31-cover plate protrusion ring. Detailed Implementation

[0008] All the devices selected in this application (parts whose specific structures are not specified) are general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0009] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0010] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0011] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0012] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0013] In addition, in the various embodiments of this utility model, each functional unit can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0014] Example 1, as Figure 1 , Figure 2 As shown, the anti-fouling sealing piston rod of this embodiment includes: piston rod 1, cover plate 3 and sealing sleeve 2. 1. Dimensions of piston rod and piston rod crown The piston rod 1 is made of 45# steel with a heat treatment process, achieving a hardness of HRC28-32, which meets the strength requirements of conventional hydraulic equipment. The diameter of the piston rod 1 body is set at 30mm, a common specification for conventional small and medium-sized hydraulic cylinders. A piston rod convex ring 11 is integrally formed on the outer circumference of the middle part of the piston rod 1. The thickness of the piston rod convex ring 11 is set at 6mm. After adjustment from the original design of 8mm, the 30mm diameter piston rod 1 is matched with a thickness of 6mm, which ensures the connection strength and avoids the piston rod convex ring 11 being too thick, causing wrinkles in the sealing sleeve 2. The outer diameter of the piston rod convex ring 11 is set at 42mm, which is 12mm larger than the piston rod 1 body, reserving space for the installation of the connecting ring 21, while avoiding the outer diameter being too large and increasing the tensile load on the sealing sleeve 2. 2. Dimensions of the cover plate and its protruding ring The cover plate 3 is made of gray cast iron HT200 with a compressive strength ≥200MPa, suitable for the cylinder end wall support requirements. The overall diameter of the cover plate 3 is set at 80mm, which is suitable for the cylinder end wall size of the piston rod 1 with a diameter of 30mm. The diameter of the conventional cylinder end wall is 2.5-3 times the diameter of the piston rod 1. The cover plate 3 has an annular mounting part on its outer periphery, with a width of 15mm and four evenly distributed mounting holes with a diameter of 8mm. After the original design was adjusted by 10mm, the M6 ​​bolts are adapted to the 8mm hole diameter. For the gray cast iron cover plate 3, the M6 ​​bolts can avoid insufficient strength of the cover plate 3 due to excessively large hole diameter. The center distance of the mounting hole is 8mm from the edge of the cover plate 3 to ensure that the edge of the cover plate 3 does not crack when the bolts are tightened. The cover plate 3 has an integrally formed cover plate protrusion ring 31 on its lower side. The size of the cover plate protrusion ring 31 is exactly the same as that of the piston rod protrusion ring 11, with a thickness of 6mm and an outer diameter of 42mm, to ensure the compatibility of the connecting ring 21. The cover plate 3 has a central hole with a diameter of 32mm, which is 2mm larger than the diameter of the piston rod 1. This provides clearance for the reciprocating movement of the piston rod 1 to avoid jamming. At the same time, a clearance of ≤2mm can reduce dust from seeping into the central hole. An annular sealing groove is provided on the inner wall of the center hole of the cover plate 3. The width of the annular sealing groove is set to 4mm and the depth is set to 2.5mm. After the original design of 5mm×3mm is adjusted, the conventional cross-sectional size of the nitrile rubber sealing ring is 3mm×3mm. The 4mm×2.5mm groove can ensure that the sealing ring has a compression of 0.5mm after being embedded, which not only ensures the sealing effect, but also avoids the cover plate 3 wall thickness being insufficient due to the groove being too deep. A nitrile rubber sealing ring with a cross-section of 3mm×3mm is embedded in the annular sealing groove. The sealing ring has a Shore A hardness of 70-75, which is suitable for the conventional sealing requirements of the hydraulic cylinder. The inner ring of the sealing ring is tightly fitted with the outer circumference of the piston rod 1, with a compression of 0.3-0.5mm, forming an effective primary seal.

[0015] 3. Dimensions of the sealing sleeve and connecting ring The sealing sleeve 2 is made of oil-resistant nitrile rubber with a Shore A hardness of 65-70, which has good elasticity and oil resistance. The sealing sleeve 2 has a bladder-like structure with a wall thickness of 2mm, maintaining the original size. The 2mm wall thickness is sufficient for nitrile rubber to withstand reciprocating expansion and contraction deformation, while avoiding cracking due to excessive thinness. It is suitable for the wrapping requirements of the 30mm diameter piston rod 1. The length of the sealing sleeve 2 in its natural state is set at 80mm, which is suitable for the normal length of the exposed section of the piston rod 1, ensuring that the sealing sleeve 2 is not overstretched when the piston rod 1 is fully extended and does not produce excessive wrinkles when it is minimally retracted. The upper and lower ends of the closed sleeve 2 are provided with connecting rings 21. The connecting rings 21 are made of brass H62 material, which has good ductility, is easy to process threads, and has excellent vulcanization bonding with nitrile rubber. The outer diameter of the connecting ring 21 is set to 42mm, which is consistent with the outer diameter of the piston rod protrusion ring 11 and the cover plate protrusion ring 31, so as to avoid the connecting ring 21 protruding and causing uneven force on the closed sleeve 2. The thickness of the connecting ring 21 is set to 5mm to ensure the strength of the connecting ring 21, while reducing the axial dimension of the overall structure. The two connection methods of connecting ring 21 with piston rod protrusion ring 11 and cover plate protrusion ring 31 are dimensionally compatible: Bolted connection: The connecting ring 21 and the corresponding piston rod protrusion ring 11 and cover plate protrusion ring 31 are all provided with 4 evenly distributed φ5mm bolt holes. The original design of φ6mm has been adjusted to fit M4 hexagon socket head cap screws. For the 5mm thick connecting ring 21, the M4 bolts have sufficient thread depth and do not penetrate the connecting ring 21. The center distance of the bolt hole is 6mm from the edge of the connecting ring 21. The surface of the connecting ring 21 is provided with a 1.5mm deep groove. The bolt head is embedded in the groove to ensure that the bolt head does not protrude and avoids scratching the sealing sleeve 2. Screw-in connection: The inner wall of the connecting ring 21 is machined with an M42×1.5 internal thread to match the outer diameter of the piston rod convex ring 11 and the cover plate convex ring 31 (42mm). The 1.5mm pitch is convenient for screwing into the brass connecting ring 21 while ensuring thread strength. The outer circumference of the piston rod convex ring 11 and the cover plate convex ring 31 is machined with matching external threads. The thread mating surfaces are coated with 0.1-0.2mm thick polytetrafluoroethylene sealant to enhance sealing and prevent thread seizing. The advantages of this embodiment are specifically reflected in: Compared to the corrugated rubber tube of CN202121058584.X, the stretchable bladder structure has a fatigue life that is more than 30% longer. When replacing the sealing sleeve, only the bolts of the connecting ring need to be removed or the connecting ring needs to be unscrewed, reducing the operation time to less than 10 minutes; The dual-sealing structure reduces dust infiltration by more than 90%, and in dusty mining conditions, the surface cleanliness retention rate of the piston rod is increased to 85%. The cover plate can be adapted to equipment with cylinder end wall diameters of 150-300mm via the annular mounting part, eliminating the need for customized fixing blocks of different specifications and providing a wide range of compatibility.

[0016] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A contamination-resistant, sealing piston rod, characterized in that, include: The piston rod (1) has an integrally formed piston rod protrusion ring (11) on its outer periphery. The cover plate (3) is used to fix the external cylinder body. It has an integrally formed cover plate protrusion ring (31) on its lower side. The cover plate has a central hole for the piston rod (1) to pass through. The closed sleeve (2) is a bladder-like structure and is fitted around the piston rod (1). It has connecting rings (21) at its upper and lower ends respectively. The upper connecting ring (21) is adapted to and fixedly connected to the piston rod protrusion ring (11), and the lower connecting ring (21) is adapted to and fixedly connected to the cover plate protrusion ring (31). The bladder-like structure of the closed sleeve (2) is made of a stretchable material.

2. The anti-fouling sealing piston rod according to claim 1, characterized in that, The connection method between the connecting ring (21) and the piston rod protrusion ring (11) and the cover plate protrusion ring (31) is bolt connection or screw-in connection; when bolt connection is used, the connecting ring (21) and the corresponding protrusion ring are provided with matching bolt holes; when screw-in connection is used, the inner wall of the connecting ring (21) and the outer circumference of the corresponding protrusion ring are provided with matching threads.

3. The anti-fouling sealing piston rod according to claim 2, characterized in that, The expandable material of the closed sleeve (2) is elastic rubber, and the wall thickness of the bladder structure is 1.5-2.5mm. In its natural state, it fits the outer periphery of the piston rod (1).

4. The anti-fouling sealing piston rod according to claim 3, characterized in that, When the cover plate (3) is fixed to the external cylinder, the outer periphery of the cover plate is provided with an annular mounting part, and the annular mounting part is provided with at least 3 evenly distributed mounting holes for connecting to the external cylinder by bolts.

5. The anti-fouling sealing piston rod according to claim 4, characterized in that, It also includes a sealing ring. The inner wall of the center hole of the cover plate (3) is provided with an annular sealing groove. The sealing ring is embedded in the annular sealing groove, and the inner ring of the sealing ring is in contact with the outer circumferential surface of the piston rod (1).

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