Highly sealed cylinder assembly

Abstract

The utility model discloses a high sealing property oil cylinder assembly, including cylinder barrel and piston rod, cylinder barrel is equipped with piston cavity, and piston cavity is communicated to the piston hole that forms on cylinder barrel end wall, and the inner peripheral wall on piston hole is provided with the sealing assembly for cooperation with piston rod, and sealing assembly includes inner sealing ring and outer sealing ring, and inner sealing ring and outer sealing ring are coaxial and set up and inner sealing ring outer wall and outer sealing ring inner wall expansion tight cooperation setting, and inner sealing ring inner peripheral wall and outer sealing ring inner peripheral wall all are with piston rod outer peripheral wall abutment and set up, and the connecting structure for conducting axial and radial load is set up between inner sealing ring and outer sealing ring, and the pre -tightening spare for applying pre -tightening action to inner sealing ring and outer sealing ring to improve the abutment intensity between inner sealing ring and outer sealing ring and piston rod is set up on cylinder barrel outer peripheral wall. The utility model has solved the problem that the sealing intensity between cylinder barrel and piston rod in traditional oil cylinder assembly is lower and is easy to appear joint or sealing failure after long time use.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, specifically to a high-sealing hydraulic cylinder assembly. Background Technology

[0002] As the core actuator of a hydraulic system, the hydraulic cylinder assembly is widely used in engineering machinery, heavy machine tools, metallurgical equipment, and other fields. The sealing performance between the cylinder barrel and the piston rod directly determines the working efficiency, operational stability, and service life of the hydraulic system. Current traditional hydraulic cylinder assemblies have significant shortcomings in their sealing structures: First, most adopt a single sealing ring design, which results in poor uniformity of the contact pressure between the cylinder and piston rod and a limited sealing contact area. Under high-pressure conditions, this easily leads to sealing gaps and hydraulic oil leakage. Second, while some employ a multi-sealing ring stacked structure, they lack an effective load transmission mechanism. Axial pressure or radial vibration can easily cause misalignment of the sealing rings, significantly reducing the fit between the sealing ring and the piston rod. Third, the lack of pre-tightening compensation components means that after prolonged use, the sealing rings will experience elastic decay due to wear, failing to maintain reliable contact with the piston rod and ultimately leading to seal failure. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model provides a high-sealing hydraulic cylinder assembly, which solves the problem of low sealing strength between the cylinder barrel and piston rod in traditional hydraulic cylinder assemblies and the tendency for joints or sealing failures to occur after long-term use.

[0004] To achieve the above objectives, this utility model provides a high-sealing hydraulic cylinder assembly, including a cylinder barrel and a piston rod for cooperating with the cylinder barrel. The cylinder barrel has a piston chamber for the piston rod to move in. The piston chamber is connected to a piston hole formed on the end wall of the cylinder barrel for the end of the piston rod to pass through. A sealing assembly for cooperating with the piston rod to seal the piston chamber is provided on the inner peripheral wall of the piston hole. The sealing assembly includes an inner sealing ring and an outer sealing ring. The inner sealing ring and the outer sealing ring are coaxially arranged, and the outer wall of the inner sealing ring and the inner wall of the outer sealing ring are tightly fitted together. The inner peripheral walls of the inner sealing ring and the outer sealing ring are both in contact with the outer peripheral wall of the piston rod. A connecting structure for transmitting axial and radial loads is provided between the inner sealing ring and the outer sealing ring. A pre-tightening member is provided on the outer peripheral wall of the cylinder barrel for applying a pre-tightening force to the inner sealing ring and the outer sealing ring to improve the contact strength between the inner sealing ring and the outer sealing ring and the piston rod.

[0005] The advantages of adopting the above technical solution are as follows: In the above technology, the inner sealing ring and the outer sealing ring are coaxially expanded and tightened, which can improve the assembly stability of the two and avoid relative misalignment. At the same time, the inner peripheral walls of both abut against the piston rod, which can increase the sealing contact area and enhance the basic sealing effect. The connection structure can effectively transmit axial and radial loads, preventing the sealing assembly from deforming or misaligning due to load when the cylinder is working, and ensuring the overall structural integrity of the sealing assembly. The above-mentioned pre-tightening component can apply a pre-tightening force to the inner and outer sealing rings, which can compensate for the wear or elasticity decay of the sealing rings due to long-term use, continuously maintain the reliable abutment between the sealing ring and the piston rod, and avoid the formation of sealing gaps. This solves the problem of low sealing strength and easy failure of traditional cylinders, improves the overall sealing performance and service life of the cylinder assembly, and ensures the operational stability of the hydraulic system.

[0006] This utility model further comprises: the connecting structure including a first circumferential protrusion circumferentially formed on the outer wall of the inner sealing ring and a second circumferential protrusion circumferentially formed on the inner wall of the outer sealing ring; the radial cross-sectional diameter of the first circumferential protrusion is larger than that of the second circumferential protrusion; the outer and inner peripheral walls of the first circumferential protrusion are connected to the outer wall of the inner sealing ring with a smooth inclined surface to form a first force-bearing surface; the outer and inner peripheral walls of the second circumferential protrusion are connected to the inner wall of the outer sealing ring with a smooth inclined surface to form a second force-bearing surface; the inner wall of the outer sealing ring is provided with a first force-bearing groove for interlocking with the first circumferential protrusion at the position corresponding to the first circumferential protrusion; the inner peripheral wall of the first force-bearing groove abuts against the first force-bearing surface; the outer wall of the inner sealing ring is provided with a second force-bearing groove for interlocking with the second circumferential protrusion at the position corresponding to the second circumferential protrusion; the inner peripheral wall of the second force-bearing groove abuts against the second force-bearing surface.

[0007] The advantages of adopting the above technical solution are as follows: The difference in diameter between the first and second circumferential protrusions optimizes the load transmission path, allowing axial and radial loads to be transmitted more evenly between the inner and outer sealing rings, avoiding localized stress concentration. Simultaneously, the smooth inclined surface design of the first and second load-bearing surfaces reduces resistance during load transmission, improves load transmission efficiency, and prevents damage to the load-bearing surfaces due to stress concentration, ensuring the long-term reliability of the connection structure. Furthermore, the insertion of the first load-bearing groove with the first circumferential protrusion and the groove wall abutting the first load-bearing surface, and the insertion of the second load-bearing groove with the second circumferential protrusion and the groove wall abutting the second load-bearing surface, enhances the tightness of the connection between the inner and outer sealing rings, preventing relative sliding and further improving the overall deformation resistance of the sealing assembly. This ensures the fit between the sealing ring and the piston rod, preventing a decrease in sealing performance due to connection structure failure, and providing stable structural support for the sealing effect of the cylinder assembly.

[0008] This utility model further includes: a plurality of pre-tightening holes evenly distributed circumferentially on the outer peripheral wall of the cylinder, all of which are connected to the piston cavity; the plurality of pre-tightening holes are divided into two groups, one group corresponding to the position of the outer sealing ring, and the other group corresponding to the position of the inner sealing ring; the pre-tightening component includes two groups of pre-tightening rings, each pre-tightening ring being composed of a plurality of arc-shaped pre-tightening strips, with adjacent pre-tightening strips abutting and fitting together; both the outer peripheral walls of the inner and outer sealing rings have circumferentially opening and closing pre-tightening grooves, with the two groups of pre-tightening rings respectively disposed in two pre-tightening grooves; the pre-tightening strips are made of elastic rubber material; the pre-tightening component also includes a plurality of pre-tightening bolts, each of which corresponds one-to-one with a plurality of pre-tightening holes and is threadedly connected; the end wall of the pre-tightening bolt is a pre-tightening wall for abutting and fitting with the outer peripheral wall of the adjacent pre-tightening strip.

[0009] The advantages of adopting the above technical solution are as follows: The pre-tightening holes are evenly distributed circumferentially and set in two groups corresponding to the inner and outer sealing rings, allowing the pre-tightening force to be precisely applied to the inner and outer sealing rings, avoiding uneven local pre-tightening force that could lead to sealing ring deformation. The pre-tightening ring is composed of arc-shaped pre-tightening strips that abut adjacent to each other, and combined with elastic rubber material, it has good elastic deformation capability, allowing for uniform transmission of pre-tightening force under the action of the pre-tightening bolts. Simultaneously, it can adapt to minor deformations of the sealing ring, preventing excessive pre-tightening force that could damage the sealing ring. The pre-tightening groove provides a stable installation space for the pre-tightening ring, preventing displacement during cylinder operation and ensuring the continuity of the pre-tightening effect. The pre-tightening bolts are threadedly connected to the pre-tightening holes, and the end pre-tightening wall abuts against the pre-tightening strips. Precise control of the pre-tightening force can be achieved by adjusting the bolts, facilitating the replenishment of pre-tightening force during later maintenance based on the wear condition of the sealing ring, continuously maintaining the contact strength between the sealing ring and the piston rod, further improving sealing reliability, and extending the replacement cycle of the sealing assembly.

[0010] The present invention further comprises: a pre-tightening ring corresponding to the inner sealing ring is positioned near the second circumferential protrusion, and a pre-tightening ring corresponding to the outer sealing ring is positioned near the first circumferential protrusion.

[0011] The advantages of adopting the above technical solution are as follows: By positioning the pre-tightening ring corresponding to the inner sealing ring close to the second circumferential protrusion, the pre-tightening force can be directly applied to the critical connection between the inner and outer sealing rings, enhancing the tightness of the connection area and preventing loosening of the connection structure due to insufficient force. Conversely, positioning the pre-tightening ring corresponding to the outer sealing ring close to the first circumferential protrusion allows the pre-tightening force to be effectively transmitted to the mating point between the outer and inner sealing rings, further strengthening the expansion and tightening effect of the inner and outer sealing rings and preventing gaps between them. This arrangement allows the pre-tightening force and the connection structure to work synergistically, improving the overall load-bearing capacity of the sealing assembly, preventing displacement of the sealing ring under axial or radial loads, ensuring stable contact between the sealing ring and the piston rod, reducing the risk of seal failure, guaranteeing the long-term sealing performance of the cylinder assembly, optimizing the pre-tightening force transmission path, improving the efficiency of the pre-tightening component, and reducing the maintenance difficulty of the sealing assembly.

[0012] This utility model further comprises: both the inner and outer sealing rings have grooves on their inner and outer peripheral walls, and a sealing ring is provided in the groove. The inner peripheral wall of the sealing ring abuts against the outer peripheral wall of the piston rod. The sealing ring is made of elastic rubber. An annular spring is provided in the inner peripheral wall of the groove, and the inner peripheral wall of the annular spring abuts against the outer peripheral wall of the sealing ring. A sealing groove is provided circumferentially on the inner peripheral wall of the inner sealing ring, and a sealing gasket is provided in the sealing groove. The sealing gasket is annular, and its inner peripheral wall abuts against the outer peripheral wall of the piston rod.

[0013] The advantages of adopting the above technical solution are as follows: The groove provides a stable installation position for the sealing ring, preventing displacement during cylinder operation. The sealing ring, made of elastic rubber with its inner circumference abutting the piston rod, utilizes the rubber's elasticity to further fill the sealing gap and enhance the sealing effect. The annular spring, positioned on the inner circumference of the groove and abutting the sealing ring, provides continuous elastic support, compensating for deformation caused by wear and preventing a decrease in sealing capacity due to elasticity decay. Furthermore, the sealing groove on the inner circumference of the inner sealing ring provides installation space for the sealing gasket. The annular gasket, with its inner circumference abutting the piston rod, forms a multi-seal structure with the sealing ring, further increasing sealing redundancy and preventing hydraulic oil leakage due to the failure of a single sealing structure. The combination of the multi-seal structure and the elastic compensation design effectively improves the sealing reliability of the cylinder assembly, adapts to sealing requirements under different working conditions, reduces sealing failures, extends cylinder maintenance cycles, and ensures efficient operation of the hydraulic system.

[0014] The present invention further includes: an annular retaining edge detachably connected to the piston hole opening for limiting the radial disengagement of the inner and outer sealing rings from the piston hole; a limiting groove for partial accommodation of the outer peripheral wall of the annular retaining edge is provided on the inner peripheral wall of the piston hole opening; and a plurality of riveting holes are provided on the end wall of the annular retaining edge, the riveting holes being located near the outer sealing ring; and a riveting pin is provided in the riveting hole for connection with the riveting hole by a riveting process after the inner and outer sealing rings are installed.

[0015] The advantages of adopting the above technical solution are as follows: the annular retaining edge is detachable, which facilitates the installation and subsequent replacement and maintenance of the sealing assembly without disassembling the overall structure of the hydraulic cylinder, thus reducing maintenance difficulty; the annular retaining edge can restrict the inner and outer sealing rings from radially dislodging from the piston hole, preventing the sealing assembly from falling off due to radial force during hydraulic cylinder operation, and ensuring the installation stability of the sealing assembly; the riveting hole is located close to the outer sealing ring, and the riveting pin is connected to the riveting hole through a riveting process, which can fix the annular retaining edge after the sealing assembly is installed, preventing the annular retaining edge from loosening, further strengthening the limiting effect on the sealing assembly, preventing displacement of the sealing assembly during long-term use, and ensuring stable contact between the sealing ring and the piston rod. Attached Figure Description

[0016] Figure 1 This is a partial sectional view of the side of this utility model; Figure 2 for Figure 1 Enlarged view of section A; Figure 3 This is a simplified view of the engagement state of the preload bolt and the preload ring in this utility model. Detailed Implementation

[0017] This utility model provides a high-sealing hydraulic cylinder assembly, including a cylinder barrel 1 and a piston rod 2 for cooperating with the cylinder barrel 1. The cylinder barrel 1 has a piston chamber 11 for the piston rod 2 to move in. The piston chamber 11 is connected to a piston hole 111 formed on the end wall of the cylinder barrel 1 for the end of the piston rod 2 to pass through. A sealing assembly for cooperating with the piston rod 2 to seal the piston chamber 11 is provided on the inner peripheral wall of the piston hole 111. The sealing assembly includes an inner sealing ring 3 and an outer sealing ring 4. The inner sealing ring 3 and the outer sealing ring 4 are coaxially arranged, and the outer wall of the inner sealing ring 3 and the inner wall of the outer sealing ring 4 are tightly fitted together. The inner peripheral walls of the inner sealing ring 3 and the outer sealing ring 4 are both in contact with the outer peripheral wall of the piston rod 2. A connecting structure for transmitting axial and radial loads is provided. A pre-tightening member is provided on the outer peripheral wall of the cylinder 1 to apply a pre-tightening force to the inner sealing ring 3 and the outer sealing ring 4 to improve the contact strength between the inner sealing ring 3 and the outer sealing ring 4 and the piston rod 2. The connecting structure includes a first circumferential protrusion 31 circumferentially formed on the outer wall of the inner sealing ring 3 and a second circumferential protrusion 41 circumferentially formed on the inner wall of the outer sealing ring 4. The radial cross-sectional diameter of the first circumferential protrusion 31 is larger than that of the second circumferential protrusion 41. The outer and inner peripheral walls of the first circumferential protrusion 31 are smoothly inclined to the outer wall of the inner sealing ring 3, forming a first force-bearing surface 32. The outer and inner peripheral walls of the second circumferential protrusion 41 are also smoothly inclined to the outer wall of the inner sealing ring 3, forming a first force-bearing surface 32. The inner walls of the sealing ring 4 are connected by a smooth inclined surface and form a second force-bearing surface 42. The inner wall of the outer sealing ring 4 is provided with a first force-bearing groove 43 for interlocking with the first circumferential protrusion 31 at the position of the first circumferential protrusion 31. The inner peripheral wall of the first force-bearing groove 43 abuts against the first force-bearing surface 32. The outer wall of the inner sealing ring 3 is provided with a second force-bearing groove 33 for interlocking with the second circumferential protrusion 41 at the position of the second circumferential protrusion 41. The inner peripheral wall of the second force-bearing groove 33 abuts against the second force-bearing surface 42. A plurality of pre-tightening holes 12 are evenly distributed circumferentially on the outer peripheral wall of the cylinder 1. The plurality of pre-tightening holes 12 are all connected to the piston cavity 11. The plurality of pre-tightening holes 12 are divided into two groups, one of which contains a plurality of pre-tightening holes 12. The pre-tightening element includes two sets of pre-tightening rings 5, each composed of several arc-shaped pre-tightening strips 51. Adjacent pre-tightening strips 51 abut against each other. Both the outer peripheral walls of the inner sealing ring 3 and the outer peripheral walls of the outer sealing ring 4 have circumferentially opening pre-tightening grooves 52. The two sets of pre-tightening rings 5 ​​are respectively disposed in two pre-tightening grooves 52. The pre-tightening strips 51 are made of elastic rubber. The pre-tightening element also includes several pre-tightening bolts 53, each corresponding to one of the pre-tightening holes 12 and threadedly connected. The end wall of each pre-tightening bolt 53 is a pre-tightening wall 531 for abutting against the outer peripheral wall of the adjacent pre-tightening strip 51.The pre-tightening ring 5 corresponding to the inner sealing ring 3 is positioned near the second circumferential protrusion 41, and the pre-tightening ring 5 corresponding to the outer sealing ring 4 is positioned near the first circumferential protrusion 31. Both the inner circumferential walls of the inner sealing ring 3 and the outer sealing ring 4 have grooves 13. A sealing ring 131 is disposed in each groove 13. The inner circumferential wall of the sealing ring 131 abuts against the outer circumferential wall of the piston rod 2. The sealing ring 131 is made of elastic rubber. An annular spring piece 132 is disposed in the inner circumferential wall of the groove 13. The inner circumferential wall of the annular spring piece 132 abuts against the outer circumferential wall of the sealing ring 131. A sealing groove 14 is circumferentially formed on the inner circumferential wall of the inner sealing ring 3. A sealing gasket 141 is provided, which is annularly arranged and whose inner peripheral wall abuts against the outer peripheral wall of the piston rod 2. An annular retaining edge 21 is detachably connected to the opening of the piston hole 111 to prevent the inner sealing ring 3 and outer sealing ring 4 from radially dislodging from the piston hole 111. A limiting groove 15 is circumferentially formed on the inner peripheral wall of the opening of the piston hole 111 to partially accommodate the outer peripheral wall of the annular retaining edge 21. A plurality of riveting holes 22 are circumferentially formed on the end wall of the annular retaining edge 21, located near the outer sealing ring 4. Riveting pins 23 are provided in the riveting holes 22 for connection via a riveting process after the inner sealing ring 3 and outer sealing ring 4 are installed.

[0018] The foregoing has shown and described the basic principles and main features of this utility model, as well as its advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications may be made to this utility model without departing from its spirit and scope. All such changes and modifications fall within the scope of protection of this utility model as defined by the appended claims and their equivalents.

Claims

1. A high-sealing hydraulic cylinder assembly, comprising a cylinder barrel and a piston rod for cooperating with the cylinder barrel, wherein the cylinder barrel has a piston chamber for the piston rod to move in, the piston chamber is connected to a piston hole formed on the end wall of the cylinder barrel for the end of the piston rod to pass through, and a sealing assembly for cooperating with the piston rod to seal the piston chamber is provided on the inner peripheral wall of the piston hole, characterized in that: The sealing assembly includes an inner sealing ring and an outer sealing ring. The inner sealing ring and the outer sealing ring are coaxially arranged, and the outer wall of the inner sealing ring is tightly fitted with the inner wall of the outer sealing ring. The inner circumferential walls of both the inner and outer sealing rings abut against the outer circumferential wall of the piston rod. A connecting structure for transmitting axial and radial loads is provided between the inner and outer sealing rings. A pre-tightening member is provided on the outer circumferential wall of the cylinder for applying a pre-tightening force to the inner and outer sealing rings to improve the abutment strength between the inner and outer sealing rings and the piston rod.

2. The high-sealing hydraulic cylinder assembly according to claim 1, characterized in that: The connection structure includes a first circumferential protrusion formed on the outer wall of the inner sealing ring and a second circumferential protrusion formed on the inner wall of the outer sealing ring. The radial cross-sectional diameter of the first circumferential protrusion is larger than that of the second circumferential protrusion. The outer and inner peripheral walls of the first circumferential protrusion are connected to the outer wall of the inner sealing ring with a smooth inclined surface to form a first force-bearing surface. The outer and inner peripheral walls of the second circumferential protrusion are connected to the inner wall of the outer sealing ring with a smooth inclined surface to form a second force-bearing surface. The inner wall of the outer sealing ring is provided with a first force-bearing groove for interlocking with the first circumferential protrusion at the position corresponding to the first circumferential protrusion. The inner peripheral wall of the first force-bearing groove abuts against the first force-bearing surface. The outer wall of the inner sealing ring is provided with a second force-bearing groove for interlocking with the second circumferential protrusion at the position corresponding to the second circumferential protrusion. The inner peripheral wall of the second force-bearing groove abuts against the second force-bearing surface.

3. The high-sealing hydraulic cylinder assembly according to claim 2, characterized in that: The cylinder has a plurality of pre-tightening holes evenly distributed circumferentially on its outer peripheral wall. Each of the pre-tightening holes is connected to the piston cavity. The pre-tightening holes are divided into two groups, one group corresponding to the outer sealing ring and the other group corresponding to the inner sealing ring. The pre-tightening component includes two groups of pre-tightening rings, each consisting of a plurality of arc-shaped pre-tightening strips. Adjacent pre-tightening strips are abutted together. Both the outer peripheral walls of the inner and outer sealing rings have circumferentially opening and closing pre-tightening grooves. The two groups of pre-tightening rings are respectively disposed in two pre-tightening grooves. The pre-tightening strips are made of elastic rubber. The pre-tightening component also includes a plurality of pre-tightening bolts, each corresponding to a pre-tightening hole and threadedly connected. The end wall of the pre-tightening bolt is a pre-tightening wall for abutting together with the outer peripheral wall of the adjacent pre-tightening strip.

4. A high-sealing hydraulic cylinder assembly according to claim 3, characterized in that: The pre-tightening ring corresponding to the inner sealing ring is positioned near the second circumferential protrusion, and the pre-tightening ring corresponding to the outer sealing ring is positioned near the first circumferential protrusion.

5. A high-sealing hydraulic cylinder assembly according to claim 1, characterized in that: Both the inner and outer sealing rings have grooves on their inner and outer peripheral walls. A sealing ring is placed in each groove, and the inner peripheral wall of the sealing ring abuts against the outer peripheral wall of the piston rod. The sealing ring is made of elastic rubber. An annular spring is placed in the inner peripheral wall of the groove, and the inner peripheral wall of the annular spring abuts against the outer peripheral wall of the sealing ring. A sealing groove is circumferentially formed on the inner peripheral wall of the inner sealing ring, and a sealing gasket is placed in the sealing groove. The sealing gasket is annular, and its inner peripheral wall abuts against the outer peripheral wall of the piston rod.

6. A high-sealing hydraulic cylinder assembly according to claim 1, characterized in that: The piston hole opening is detachably connected to an annular retaining edge for limiting the radial disengagement of the inner and outer sealing rings from the piston hole. A limiting groove is provided circumferentially on the inner peripheral wall of the piston hole opening for partial accommodation of the outer peripheral wall of the annular retaining edge. A plurality of riveting holes are provided circumferentially on the end wall of the annular retaining edge. The riveting holes are located near the outer sealing ring. A riveting pin is provided in the riveting hole for connecting with the riveting hole through a riveting process after the inner and outer sealing rings are installed.

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