Integrated piston rod and hydraulic cylinder comprising same

Abstract

The utility model discloses an integrated piston rod and hydraulic cylinder containing it. The integrated piston rod is integrally processed and formed, and the head part constitutes a piston head main body, and a plurality of annular grooves are respectively arranged on the outer wall of the piston head main body and the tail part of the rod body for embedding and sealing guiding components. The hydraulic cylinder comprises a cylinder barrel, an integrated piston rod, a first sealing guiding component arranged on the piston head main body, a second sealing guiding component arranged on the tail part of the cylinder barrel and an end cover. The first and second sealing guiding components comprise sealing components with alternately stacked elastic sealing rings and elastic metal clamps and multi-petal split guiding components. This eliminates the split connection defects, simplifies the processing and improves the reliability; the composite sealing structure provides bidirectional sealing and wear self-compensation; the modular design allows flexible configuration of the number and position of the sealing guiding components, significantly improving the sealing performance, impact resistance and service life of the hydraulic cylinder under complex working conditions such as high-speed rotation and high side load.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder structure technology, specifically to an integrated piston rod and a hydraulic cylinder containing therein. Background Technology

[0002] In existing technologies, the piston head and piston rod of hydraulic cylinders are designed as separate units, typically connected by a nut. However, this design presents several problems: First, they are prone to loosening, especially during high-speed rotation of the cylinder, where the piston head and piston rod can easily detach, compromising safety. Second, operation is inconvenient; for example, a piston head with a diameter of 400-500 mm can weigh half a ton or even one or two tons, making it extremely difficult for workers to connect it to the piston rod. Third, sealing performance is suboptimal. Due to the weight of the piston and the fixed sealing ring, the sealing ring wears severely, affecting sealing performance. Furthermore, existing technologies use guide strips made of a mixture of polytetrafluoroethylene (PTFE) and copper powder. While these guide strips are replaceable, their soft material limits their load-bearing capacity. Under lateral forces of hundreds or tens of tons, the guide strip wears rapidly, causing direct contact and friction between the piston head and piston rod. In such cases, the sealing ring and guide strip of traditional hydraulic cylinders are in relatively fixed positions. To increase the lateral force, the hydraulic cylinder must be remanufactured, significantly reducing its assemblability and combinability. Furthermore, in existing technologies, the piston head and piston rod of hydraulic cylinders are typically designed as separate units connected by mechanical means such as threads. This structure has the following inherent defects: due to the stepped structure at the connection between the piston head and piston rod, the cutting tool cannot fully reach the right-angle area at the root during machining, creating a machining blind spot. More importantly, the piston rod surface needs to be chrome-plated or heat-treated to improve wear resistance, while the piston head needs to maintain a relatively low hardness to meet the assembly and working requirements of the seals. This separate structure makes it difficult to achieve uniform heat treatment in the right-angle transition area at the root of the piston rod, which easily leads to stress concentration in this area, becoming a weak point for fatigue fracture of the component, seriously restricting the reliability and service life of the product. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this utility model discloses an integrated piston rod and a hydraulic cylinder containing it. The integrated piston rod structure eliminates the defects of separate connections, and the composite sealing structure of the hydraulic cylinder provides bidirectional sealing and wear self-compensation. The modular design allows for flexible configuration of the number and position of sealing guide components, significantly improving the mechanical performance of the hydraulic cylinder under complex working conditions such as high-speed rotation and high side load.

[0004] To achieve the above technical objectives, on the one hand, this utility model proposes an integrated piston rod, including an integrally machined rod body, the head of which constitutes the piston head body; the outer wall of the piston head body is provided with a plurality of annular grooves along the axial direction, the annular grooves being used to embed sealing and guiding components.

[0005] The integrated piston rod structure proposed in this utility model is formed by integrally machining a single metal rod. Its head directly constitutes the piston head body, and the required annular groove is directly formed on the outer wall of the piston head body through machining.

[0006] This technical solution firstly completely eliminates the steps and right-angle transitions at the traditional split-part connection, allowing the piston rod to undergo overall heat treatment. This ensures uniform hardness and material properties throughout its entire length, avoiding abrupt changes in local properties. Secondly, this structure removes structural limitations from the machining of the annular grooves. Regardless of whether the heat treatment process is arranged before or after the annular groove machining, the dimensional accuracy and surface quality of all annular grooves remain consistent. Most importantly, this design fundamentally solves the stress concentration problem at the piston rod root caused by inconsistent heat treatment and geometric abrupt changes, significantly reducing the risk of fatigue fracture and substantially improving the component's reliability and service life. Furthermore, this solution simplifies the production process, eliminating the need for split manufacturing and assembly, effectively reducing manufacturing costs.

[0007] As a preferred technical solution, the cross-sectional shape of the annular groove is rectangular, V-shaped, T-shaped, or W-shaped; And / or, at least one of the annular grooves is fitted with a magnetic ring for position detection; And / or, at least one of the annular grooves is fitted with a magnetic adsorption ring for adsorbing ferromagnetic impurities.

[0008] This utility model also discloses a hydraulic cylinder containing the aforementioned integrated piston rod, comprising: Cylinder; the integral piston rod is axially movable within the cylinder; The first sealing guide structure is disposed in the annular groove of the piston head body; The second sealing guide structure is disposed in the annular groove at the tail of the cylinder; A cover plate is fixed to one end of the cylinder and forms a rodless cavity with the piston head body. The cover plate is provided with a first oil inlet. The space between the first sealing guide structure and the second sealing guide structure forms a rod cavity, and the cylinder is provided with a second oil inlet that communicates with the rod cavity.

[0009] As a preferred technical solution, the first sealing guide structure and / or the second sealing guide structure include a sealing assembly, the sealing assembly including a central sealing support block, end sealing support blocks symmetrically arranged on both axial sides of the central sealing support block, and at least one set of sealing units disposed between the central sealing support block and the end sealing support blocks; the sealing unit includes elastic sealing rings and elastic metal clips alternately stacked.

[0010] As a preferred technical solution, the cross-section of the central sealing support block is symmetrical butterfly-shaped; and / or, both the elastic sealing ring and the elastic metal clip are V-shaped; and / or, the material of the elastic metal clip is a copper-based alloy.

[0011] As a preferred technical solution, the radial height of the elastic sealing ring and the central sealing support block is greater than the radial height of the elastic metal clip, and the extended portion of them constitutes an exposed wing for interference fit with the annular groove; the adjacent exposed wings and the elastic metal clip form a chip storage groove.

[0012] As a preferred technical solution, the first sealing guide structure includes a first guide component, the second sealing guide structure includes a second guide component, and the inner side of the first guide component and the outer side of the second guide component are provided with positioning protrusions that engage with the annular groove.

[0013] As a preferred technical solution, the first and second guide components are multi-lobed split arc-shaped structures; and / or, multiple sealing components are arranged alternately with the first guide component / second guide component in the annular groove of the piston head body.

[0014] As a preferred technical solution, the main body of the first and second guide components is a steel substrate; Alternatively, the main body of the first and second guide components is a steel substrate, and a sealing groove is opened circumferentially on the outside of the first guide component or the inside of the second guide component, and a sealing ring is set in the sealing groove; Alternatively, the main body of the first and second guide components is a steel substrate, and a wear-resistant layer or tin bronze or other copper alloy layer is provided on the outside of the first guide component or the inside of the second guide component to form a copper-steel composite.

[0015] As a preferred technical solution, a pressure-resistant sealing steel ring and a static sealing ring located in an annular groove are provided between the first sealing guide structure and the piston head body, and / or between the second sealing guide structure and the cylinder.

[0016] As a preferred technical solution, a position detection system is also included, which includes a position sensor disposed on the outside of the cylinder and a magnetic ring disposed on the integrated piston rod; the cylinder is made of non-magnetic metal material.

[0017] This utility model has the following technical effects: Firstly, at the structural level, the integrated piston rod combines the traditional split piston and piston rod into a single component, fundamentally eliminating the problems of loosening, misalignment, and stress concentration that may occur due to threaded connections; moreover, it is simpler to process and manufacture and has a lower cost. Secondly, in terms of sealing performance, this utility model constructs a composite sealing system with a flexible sealing interface and a rigid elastic support as the core. The system forms a bidirectional sealing mechanism with both immediate sealing performance and long-term compensation capability through the alternating stacking of V-shaped sealing rings and elastic metal clips. In addition, the fitting design of the first sealing component and the annular groove effectively restricts circumferential rotation, making it particularly suitable for the harsh working conditions of high-speed rotating cylinders. Furthermore, the first guide assembly adopts a multi-lobed, split-segment arc structure, achieving radial positioning without the need for fasteners, and sealing strips at the joints prevent leakage. The cylinder can rotate freely at high speeds without piston detachment or abnormal wear of the sealing rings, meeting the long-life, high-reliability operation requirements of rotary cylinders under complex conditions such as high-frequency impacts and side loads. The alternating arrangement of the sealing assembly with the first and second guide assemblies further optimizes the axial force distribution, enhancing the overall stability and impact resistance of the hydraulic cylinder under complex loads. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 A three-dimensional view of the hydraulic cylinder of this utility model is shown; Figure 2 A three-dimensional view of the hydraulic cylinder barrel of this utility model is shown; Figure 3 A three-dimensional view of the integrated piston rod of this utility model is shown; Figure 4 A cross-sectional view showing the inward thrust of the hydraulic cylinder of this utility model is shown; Figure 5 This invention presents a cross-sectional view showing the hydraulic cylinder extending outwards. Figure 6 A three-dimensional view of the piston head body of this utility model is shown; Figure 7 A partial three-dimensional view of the first sealing component of this utility model is shown; Figure 8 A schematic diagram of the sealing unit of this utility model is shown; Figure 9 A partially enlarged assembly view of the piston head body, the first sealing assembly, and the first guide assembly according to one embodiment is shown. Figure 10 A partially enlarged assembly view of the piston head body, the first sealing assembly, and the first guide assembly according to another embodiment is shown. Figure 11 A three-dimensional view of the first guide component of this utility model is shown; Figure 12 A cross-sectional view of a first guide component according to one embodiment is shown; Figure 13 A cross-sectional view of a first guide component according to another embodiment is shown; Figure 14 A cross-sectional view of a first guide component according to another embodiment is shown; Figure 15 A partial cross-sectional view of the second sealing guide structure of this utility model is shown.

[0019] 1. Cylinder barrel; 1a. First oil inlet; 2. Integrated piston rod; 2a. Piston head body; 3. First sealing guide structure; 4. Second sealing guide structure; 5. Cover plate; 5a. Second oil inlet; 6. Annular groove; 7. First sealing assembly; 8. First guide assembly; 8a. Steel base; 8b. Sealing strip; 8c. Wear-resistant ring; 8d. Sealing ring; 9. Central sealing support block; 10. Elastic sealing ring; 11. Elastic metal clip; 12. End sealing support block; 13. Exposed fins; 14. Chip collection groove; 15. Pressure-resistant sealing steel ring; 16. Static sealing ring; 17. Fixed ring; 18. Position sensor; 19. Magnetic ring; 20. Magnetic adsorption ring; 21. Second sealing assembly; 22. Second guide assembly; 23. Dustproof sealing ring; 24. Chip collection groove. Detailed Implementation

[0020] To facilitate understanding of this utility model, a more comprehensive description of the present utility model will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the present utility model in any way, i.e., not limiting the scope of protection of the present utility model. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art.

[0021] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between 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.

[0022] like Figures 1-5 As shown, this embodiment provides a hydraulic cylinder, including a cylinder barrel 1 and an integral piston rod 2; the integral piston rod 2 integrates a traditional piston and piston rod by integral molding, and the head and tail of the piston rod are respectively fitted with a first sealing guide structure 3 and a second sealing guide structure 4 in series.

[0023] The piston rod head serves as the piston head body 2a, and the piston head body no longer has the boss of the traditional product, but a certain number of annular grooves 6 are uniformly opened along the axial direction on its outer wall; the cylinder barrel 1 of the hydraulic cylinder also has a certain number of annular grooves 6 uniformly opened along the axial direction on its inner wall; the corresponding sealing guide component is annular and is embedded in the annular grooves 6 of the piston rod head and the cylinder barrel 1 tail.

[0024] The integrated piston rod 2 structure adopted in this application has the following significant manufacturing advantages: the piston rod can be directly made from standard bar stock, and can be formed by machining the required annular groove 6 on its surface, eliminating the need for forging the piston head and then cutting it, or manufacturing the piston head and piston rod separately and then assembling them, as is the case with traditional processes. This integrated design not only eliminates the complex forging and assembly processes, but also saves materials, reduces the weight of the piston head by 15-20%, saves 30% of processing time, and eliminates the inherent defects of split structures such as looseness, misalignment errors, and stress concentration at the connection points.

[0025] In some specific embodiments, the cross-section of the annular groove 6 can be rectangular, V-shaped, T-shaped, W-shaped, etc.; among them, the rectangular groove has a better effect in bearing horizontal pressure, so that the first sealing component 7 fits better with the cylinder wall and the piston runs more smoothly.

[0026] A cover plate 5 is bolted to the side of the hydraulic cylinder near the piston head body, thereby covering the radial end face; the space between the piston head body and the cover plate 5 is the rodless chamber of the hydraulic cylinder, and the cover plate 5 has a first oil inlet 5a in the center to inject pressurized oil and air into the rodless chamber; the space between the first sealing guide structure 3 and the second sealing guide structure 4 is the rod chamber, and the cylinder wall of this section is provided with a second oil inlet 1a.

[0027] Through the above technical solution, pressurized oil enters the rodless chamber, and the oil pressure pushes the piston head body, causing the integral piston rod 2, which carries the first sealing guide structure 3, to move outward along the cylinder 1 axis. The second sealing guide structure 4, because it is embedded in the annular groove 6 at the tail of the cylinder 1, does not move axially and slides against the integral piston rod 2. When pressurized oil enters the rod chamber, the oil pressure pushes the first sealing guide structure 3 and causes the integral piston rod 2 to return axially.

[0028] The assembly sequence of the hydraulic cylinder is as follows: First, the second sealing guide structure 4 is installed in the annular groove 6 on the inner wall of the cylinder barrel 1; then, the integrated piston rod 2 and the first sealing guide structure 3 fitted on it are installed from the other side of the cylinder barrel 1; finally, the cover plate 5 is installed on this side of the cylinder barrel 1 to complete the overall encapsulation.

[0029] like Figures 6-14 As shown, this embodiment takes the first sealing guide structure 3 as an example to describe its structure in detail. The first sealing guide structure 3 includes an annular first sealing component 7 and an annular first guide component 8. In some specific embodiments, the first sealing assembly 7 adopts a multi-layered symmetrical composite structure, including a central sealing support block 9, end sealing supports 12 disposed on both axial sides of the central sealing support block 9, and at least one set of sealing units symmetrically disposed between the central sealing support block 9 and the end sealing support blocks 12; the sealing unit includes elastic sealing rings 10 and elastic metal clips 11 alternately stacked. In the radial end faces of the annular first sealing assembly 7, one inner end abuts against the annular groove 6 of the piston head body, and the other outer end contacts the inner wall of the cylinder 1.

[0030] Compared to a pure polymer sealing structure, the embedded elastic metal clip 11 significantly enhances the structural rigidity of the entire first sealing assembly 7. When subjected to high-pressure oil, the clip prevents excessive compression deformation and gap jamming of the sealing ring, improving the assembly's impact and extrusion resistance. Simultaneously, its cooperation with the annular groove 6 effectively restricts the relative circumferential rotation between the first sealing assembly 7 and the piston head body, giving the entire sealing system excellent torsional resistance, making it particularly suitable for high-speed rotating hydraulic cylinder applications.

[0031] Specifically, the central sealing support block 9 has a symmetrical butterfly-shaped cross-section, and its axial end faces are designed as inlay surfaces for precisely fitting the V-shaped elastic sealing rings 10. Each V-shaped sealing ring is separated and supported by a V-shaped elastic metal clip 11 that matches its shape.

[0032] Based on a symmetrical butterfly structure design, the elastic metal clip 11 provides balanced and effective support to the sealing rings on both sides through its elastic deformation, regardless of whether hydraulic oil is applied from the rodless or rod chamber, thus achieving excellent bidirectional sealing performance. Even in extreme cases where the elastic sealing ring 10 experiences partial failure, the metal clip, due to its non-linear elastic deformation characteristics, can still provide a certain degree of compressive support, acting as a final sealing barrier and greatly enhancing the system's safety redundancy.

[0033] Preferably, the material of the elastic sealing ring 10 includes, but is not limited to, polyurethane, nylon, polytetrafluoroethylene, rubber, etc.; the material of the elastic metal clip 11 includes, but is not limited to, copper-based alloys, spring steel, nickel-based elastic alloys, etc. In this embodiment, tin bronze, aluminum bronze, beryllium bronze, or ordinary brass is preferred because copper has a high coefficient of thermal expansion. During operation, the heat generated causes the first sealing component 7 to expand radially, which dynamically reduces the gap between the guide belt component and the hydraulic cylinder wall and piston head, achieving a self-tightening effect, improving sealing and guiding accuracy, and preventing leakage. At the same time, it can provide excellent wear resistance and a low coefficient of friction, reduce wear on the inner wall of the hydraulic cylinder, and extend the system life.

[0034] In this embodiment, the sealing ring and the elastic metal clip 11 are not simply physical superpositions, but constitute an organic, functionally integrated sealing system, solving the technical contradiction in traditional seals of the difficulty in simultaneously achieving long-term effectiveness, reliability, stability, and low friction. Specifically, firstly, this combination forms a binary structure of "flexible sealing interface" and "rigid elastic support": the sealing ring, as the flexible main body, provides excellent initial sealing and microscopic fit to the inner wall of the cylinder 1, ensuring immediate sealing; while the elastic metal clip 11, as the rigid skeleton, provides strong and lasting axial elastic force, keeping the sealing ring tightly pressed against the sealing interface at all times. This mechanism effectively overcomes the inherent defects of the purely elastic sealing ring 10, which is easily squeezed out under high pressure and has insufficient compensation after wear. Secondly, during the initial operation, the sealing ring is primarily responsible for sealing, with the elastic metal clip 11 providing continuous and adaptive axial elastic back pressure. As the sealing ring wears naturally over long-term operation, the elastic deformation of the metal clip continuously and automatically compensates for this wear, pushing the sealing ring forward and maintaining a dynamic and constant pressure on the sealing surface. This achieves a transition from relying on material elasticity to relying on structural elasticity, greatly extending the effective lifespan of the sealing system. Thirdly, this combination exhibits strong adaptability to complex operating conditions such as system pressure fluctuations, temperature changes, and mechanical vibrations. When system pressure rises sharply, the rigid support of the metal clip prevents excessive deformation and damage to the sealing ring; when temperature changes cause thermal expansion and contraction of the material, the continuous output of the elastic force of the metal clip offsets the changes in clearance. This synergistic effect ensures stable sealing performance over a wide operating range, avoiding intermittent leakage.

[0035] In some specific embodiments, such as Figure 8 The elastic metal clip 11 has a thickness of 0.2-1.0 mm, giving the component axial elasticity; the radial height of the elastic metal clip 11 is h1, and the radial height of the central sealing support block 9 and the sealing ring is h2, Δh=h2-h1 and Δh≥0.3 mm; the portion of the central sealing support block 9 and the sealing ring extending out of the elastic metal clip 11 is an exposed wing 13, which is used to fit into the annular groove 6. The inner side of the first sealing component 7 achieves circumferential sealing and positioning through the interference fit between the exposed wing 13 and the annular groove 6.

[0036] This interlocking structure effectively restricts the relative radial movement and circumferential rotation of the sealing ring and the annular groove 6, greatly enhancing the overall component's resistance to circumferential torsion and preventing loosening of the component under dynamic operating conditions. Experiments show that after approximately 2000 cycles of break-in, the burrs on the elastic metal clip 11 are eliminated, and the surface roughness of the elastic metal clip 11 decreases from Ra3.2 to Ra0.4 during the break-in process with the inner wall of the hydraulic cylinder, forming an ideal metal-elastic composite sealing interface.

[0037] A chip storage groove 14 is formed by the outward flaps of two adjacent sealing rings and the elastic metal clip 11. This groove space is used to capture and contain particulate impurities in the oil. When the integrated piston rod 2 moves axially, the outward flaps of the sealing rings near the inner wall of the cylinder 1 scrape off contaminants (such as sludge and metal shavings) attached to the inner wall of the cylinder 1. Under the action of oil pressure, the scraped impurities will enter the relatively spacious cavity of the chip storage groove 14 along with a small amount of oil. The kinetic energy of the oil flow will be significantly reduced, and heavier solid particles (such as metal shavings) will settle under gravity, while impurities such as sludge will be trapped in this space. As the outward flaps of the sealing rings move subsequently, they will close the entrance of the chip storage groove 14 again, and these impurities are effectively captured and stored in the groove, preventing them from circulating in the hydraulic system.

[0038] When the first sealing assembly 7 is assembled into the piston head body, the exposed fins 13 preferentially contact the cylinder wall, and the spring effect of the elastic metal clip 11 provides continuous compensation. The sealing ring buffers the assembly stress through elastic deformation. Preferably, the elastic metal clip 11 is chamfered at both ends to eliminate initial burrs, while increasing the oil film formation speed by 50% and reducing the starting friction coefficient.

[0039] In some specific embodiments, a pressure-resistant sealing steel ring 15 is provided between the first sealing component 7 and the outer wall of the piston head body; the sealing steel ring and the piston head body adopt a clearance fit, which facilitates axial position adjustment to support and position the first sealing component 7. To further improve sealing reliability, a static sealing ring 16 is provided in each annular groove 6 at the bottom of the sealing steel ring to achieve effective static sealing of the annular groove 6. This structure not only allows multiple annular sealing rings to be arranged in series to enhance the system's sealing capability, but is also particularly suitable for high-speed rotating rotary cylinder conditions.

[0040] After the axial position of the first sealing component 7 is determined, clamping and positioning can be achieved by setting the first guide component 8 on one or both sides; alternatively, the first guide component 8 can be set on one side, and a fixing ring 17 for installing the position sensing component can be set on the other side to form a stable axial constraint. Preferably, the piston head body is machined with a sufficient number of annular grooves 6. The excess annular grooves 6 structure provides space for the adjustment and displacement of the sealing steel ring, and also reserves margin for functional expansion of the system.

[0041] Compared to the complex process of traditional hydraulic cylinder seals requiring heating and expansion before installation, the first sealing component 7 of this invention can be directly inserted radially into the annular groove 6 from the end of the piston head body, making the assembly process simple and efficient. This installation method avoids initial damage to the seal due to excessive stretching, significantly extending the service life of the sealing element and greatly reducing maintenance costs and time.

[0042] In some specific embodiments of this utility model, the first guide component 8 adopts a multi-lobed split arc-shaped structure, with its inner side fitted onto the outer side of the piston head body and its outer side slidingly engaging with the inner wall of the cylinder to guide the relative movement between the piston head body and the inner wall of the cylinder. The inner side of the first guide component 8 is provided with a positioning protrusion structure that matches the shape of the annular groove 6 on the piston head body to achieve radial positioning and assembly stability. Its outer side is machined into a smooth arc surface to ensure smooth relative movement with the inner wall of the cylinder 1.

[0043] In a preferred embodiment, the first guide component 8 is formed by the mating of two C-shaped arc segments. Alternatively, a three- or more-segment structure can be used depending on the actual size and assembly requirements. Each segment is reliably positioned within the cylinder 1 by engaging its corresponding annular groove 6 via its inner positioning protrusion. No additional fasteners are required, making assembly simple and eliminating the risk of detachment. After the component is installed, a sealing strip 8b must be installed at its joints to prevent hydraulic oil leakage along the parting surface.

[0044] Regarding materials and surface treatment, the main body of the first guide component 8 is a steel substrate 8a to ensure overall structural strength. To further enhance its functional performance, any of the following composite structures can be adopted: a sealing groove is opened circumferentially on the outer side of the steel substrate and a sealing ring 8d is set in the sealing groove to enhance the boundary sealing effect; or, a wear-resistant layer 8c is set on the outer and / or inner side of the first guide component 8; or, a 0.5~1.5mm thick tin bronze or other copper alloy layer is coated on the outer surface of the steel substrate through a composite welding process to form a copper-steel composite, which combines the strength of steel with the wear resistance and low friction characteristics of copper alloy; or, tin bronze or copper alloy wear-resistant layers are set on both the inner and outer sides of the steel substrate to achieve bidirectional protection of the piston head body and the inner wall of the cylinder 1, significantly extending the service life of the first guide component 8 and its mating parts.

[0045] The first guide component 8 and the annular groove 6 cooperate to generate a radial constraint force; the stepped surface of the groove forms an axial mechanical barrier, which doubles the inhibition of the axial displacement of the sealing guide component.

[0046] In practical applications, both the first sealing component 7 and the first guiding component 8 can be configured as multiple sets, and sequentially fitted into the annular groove 6 on the outer side of the piston head body in a series configuration. To adapt to different cylinder models and varying working conditions, a sufficient number of annular grooves 6 can be pre-machined on the piston head body, allowing users to flexibly adjust the installation quantity and axial arrangement of each component according to actual wear conditions and sealing requirements.

[0047] As a preferred embodiment, multiple first sealing components 7 and first guide components 8 can be arranged in an alternating manner to form a modular alternating structure of "first guide component 8 - first sealing component 7 - first guide component 8". This layout can evenly distribute the guiding and sealing functions in the axial dimension, which not only ensures the overall stability of the piston movement, but also effectively improves the hydraulic cylinder's resistance to eccentric loads and pressure shocks through multi-point support, thereby enhancing the system's reliability under complex working conditions.

[0048] Based on the above technical solution, compared to the threaded connection between the piston and piston rod in the prior art, the integrated piston rod 2 of this application is applicable to rotary cylinders. During high-speed rotation, the piston and piston rod in the prior art may detach under high centrifugal force, causing accidents, or the piston head may wear down the sealing ring, leading to rapid damage. However, the integrated piston rod 2 of this application avoids this situation, and the setting of the sealing guide component does not affect the overall performance of the sealing guide. Because the piston head body does not need to be threadedly locked to the piston rod, the cylinder can rotate freely without detaching or falling off, making it suitable for applications requiring rotation.

[0049] In some specific embodiments of this utility model, the hydraulic cylinder can be configured with a position sensing system to achieve precise control of the piston stroke. The system includes a position sensor 18 fixed to the outside of the cylinder barrel 1 and a magnetic ring 19 fitted on the piston head body; when the piston head body moves axially, it drives the magnetic ring 19 to move synchronously; when the magnetic ring 19 approaches the effective sensing area of ​​the position sensor 18, the sensor immediately sends a switching signal to the control unit (such as a PLC or a solenoid valve), triggering the actuator to act, so that the piston rod stops accurately at a predetermined position.

[0050] Preferably, the position sensor 18 is a reed switch or a Hall sensor; the matching magnetic ring 19 is preferably installed in an annular groove on the outer side of the piston head body. To ensure reliable transmission of the magnetic field signal, the cylinder 1 is preferably made of a non-magnetic metal material, such as austenitic stainless steel, aluminum, or copper alloy. In addition, fixing rings 17 can be provided in the annular grooves 6 on both sides of the magnetic ring 19 to achieve axial positioning of the magnetic ring 19 and effectively isolate the hydraulic oil to prevent it from affecting the performance of the magnet.

[0051] In a preferred embodiment of this invention, a magnetic adsorption ring 20 is fitted into one or more annular grooves 6 between the first sealing component 7 and the first guiding component 8. A preset gap is maintained between the outer circumferential surface of the adsorption ring and the inner wall of the cylinder 1, forming a chip-containing space for accommodating and depositing metal shavings and other solid impurities in the oil.

[0052] The magnetic attraction ring 20 effectively adsorbs ferromagnetic particles in the hydraulic oil and traps them within the chip-holding space, preventing these impurities from diffusing with the oil circulation to the friction pairs inside the hydraulic cylinder. This design significantly reduces the risk of abnormal wear on critical sealing and guide surfaces, effectively extending the overall service life and operational reliability of the hydraulic cylinder.

[0053] Figure 15 As shown, the second sealing guide structure 4 includes multiple annular second sealing components 21 and annular second guide components 22. The second sealing components have the same structure as the first sealing components. A pressure-resistant sealing steel ring and a static sealing ring located in the annular groove are provided between the second sealing guide structure and the cylinder. The second guide component is also a multi-lobed split structure with a smooth inner wall and a wear-resistant layer between it and the integrated piston rod. The outer side of the second guide component has a positioning protrusion that matches the annular groove, and its inner side slides with the tail of the piston rod to guide the relative movement between the tail of the piston rod and the cylinder. A dustproof sealing ring 23 is provided between the outermost second guide component and the integrated piston rod. A chip groove 24 for storing impurities can also be provided between any two adjacent second guide components 22.

[0054] The main body of the second guide component is a steel substrate, and a sealing groove is opened circumferentially on the inner side of the second guide component and a sealing ring is provided in the sealing groove; or, the main body of the second guide component is a steel substrate, and a wear-resistant layer or tin bronze or other copper alloy layer is provided on the inner side of the second guide component to form a copper-steel composite.

[0055] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. For those skilled in the art, several simple improvements can be made without departing from the concept of the present invention, and all such improvements should be considered to fall within the scope of protection of the present invention.

Claims

1. A one-piece piston rod, characterized in that, It includes a rod body that is integrally machined, the head of which constitutes the piston head body; the outer wall of the piston head body is provided with a plurality of annular grooves along the axial direction, the annular grooves being used to embed sealing guide components.

2. The one-piece piston rod as described in claim 1, characterized in that, The cross-sectional shape of the annular groove is rectangular, V-shaped, T-shaped, or W-shaped; And / or, at least one of the annular grooves is fitted with a magnetic ring for position detection; And / or, at least one of the annular grooves is fitted with a magnetic adsorption ring for adsorbing ferromagnetic impurities.

3. A hydraulic cylinder comprising the integral piston rod as described in claim 1, characterized in that, include: Cylinder; The integrated piston rod is axially movable within the cylinder. The first sealing guide structure is disposed in the annular groove of the piston head body; The second sealing guide structure is disposed in the annular groove at the tail of the cylinder; A cover plate is fixed to one end of the cylinder and forms a rodless cavity with the piston head body. The cover plate is provided with a first oil inlet. The space between the first sealing guide structure and the second sealing guide structure forms a rod cavity, and the cylinder is provided with a second oil inlet that communicates with the rod cavity.

4. The hydraulic cylinder according to claim 3, characterized in that, The first sealing guide structure, and / or the second sealing guide structure, includes a sealing assembly. The sealing assembly includes a central sealing support block, end sealing support blocks symmetrically arranged on both axial sides of the central sealing support block, and at least one set of sealing units disposed between the central sealing support block and the end sealing support blocks. The sealing unit includes elastic sealing rings and elastic metal clips that are alternately stacked.

5. The hydraulic cylinder according to claim 4, characterized in that, The cross-section of the central sealing support block is symmetrical butterfly-shaped; and / or, both the elastic sealing ring and the elastic metal clip are V-shaped; and / or, the material of the elastic metal clip is a copper-based alloy.

6. The hydraulic cylinder according to claim 5, characterized in that, The radial height of the elastic sealing ring and the central sealing support block is greater than the radial height of the elastic metal clip, and their extended portions form exposed wings for interference fit with the annular groove; adjacent exposed wings and elastic metal clips enclose each other to form a chip storage groove.

7. The hydraulic cylinder according to claim 4, characterized in that, The first sealing guide structure includes a first guide component, and the second sealing guide structure includes a second guide component. The inner side of the first guide component and the outer side of the second guide component are provided with positioning protrusions that engage with the annular groove.

8. The hydraulic cylinder according to claim 7, characterized in that, The first and second guide components are multi-lobed split arc-shaped structures; and / or, multiple sealing components are arranged alternately with the first guide component / second guide component in the annular groove of the piston head body; and / or, the main body of the first and second guide components is a steel substrate. Alternatively, the main body of the first and second guide components is a steel substrate, and a sealing groove is opened circumferentially on the outside of the first guide component or the inside of the second guide component, and a sealing ring is set in the sealing groove; Alternatively, the main body of the first and second guide components is a steel substrate, and a wear-resistant layer or tin bronze or other copper alloy layer is provided on the outside of the first guide component or the inside of the second guide component to form a copper-steel composite.

9. The hydraulic cylinder according to claim 3, characterized in that, A pressure-resistant sealing steel ring and a static sealing ring located in an annular groove are provided between the first sealing guide structure and the piston head body, and / or between the second sealing guide structure and the cylinder. And / or, it also includes a position detection system, the position detection system including a position sensor disposed on the outside of the cylinder and a magnetic ring disposed on the integral piston rod; the cylinder is made of a non-magnetic metal material.

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