Flange and end cover gapless alignment oil cylinder

Abstract

The utility model provides a flange and end cover gapless counterpoint oil cylinder which comprises a cylinder barrel, an upper end cover, a lower end cover, a pair of cylinder barrel flanges and a pair of cylinder barrel check rings, the cylinder barrel check rings are adjustably arranged in the cylinder barrel flanges, the cylinder barrel flanges are in threaded connection with the two ends of the cylinder barrel through the cylinder barrel check rings, and the upper end cover and the lower end cover are in threaded connection. The cylinder barrel flange at one end is in bolted connection with the upper end cover, and the cylinder barrel flange at the other end is in bolted connection with the lower end cover; the inner side end face of the upper end cover and the inner side end face of the lower end cover are attached to the corresponding inner side end faces of the cylinder barrel flanges respectively. According to the flange and end cover gapless alignment oil cylinder, gapless fit between the oil cylinder flange and the upper end cover and between the oil cylinder flange and the lower end cover can be ensured, so that the sealing performance of the oil cylinder is improved, and the defect that assembling and positioning of an ultra-long valve group are interfered is overcome.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinders, specifically to a hydraulic cylinder for seamless alignment of a flange and an end cap. Background Technology

[0002] In the design of hydraulic cylinders, it is common to directly mount valve assemblies onto the cylinder to improve response speed and reduce leakage risk. Simultaneously, to facilitate disassembly and maintenance and avoid deformation of the cylinder bore caused by welding, flanges are connected to the cylinder via threads. In practical applications, the valve assembly length often exceeds the width of the end cap's outer diameter, forcing the flange to also have its outer diameter milled to accommodate the extra-long valve assembly. During assembly, due to the difficulty in controlling the starting point of the cylinder and flange threads, when the end cap face simultaneously mates with both the cylinder and flange faces, the outer diameter of the flange is not parallel to the outer diameter of the end cap, leading to problems with valve assembly installation. To make the outer diameter of the flange parallel to the outer diameter of the end cap, the engagement depth needs to be adjusted, resulting in a gap between the end cap face and the cylinder or flange face, reducing design strength and stability.

[0003] Utility model patent CN220118434U discloses a flange connection structure for a hydraulic cylinder, including a flange fitted on a positioning step. The positioning step surrounds the outer side of the hydraulic cylinder barrel. An external pin hole is formed around the outer side of the flange, penetrating the flange and its bottom entering the outer wall of the hydraulic cylinder to form an internal pin hole. An anti-rotation pin is provided in the external pin hole, with one end passing through the external pin hole and connecting to the internal pin hole, and the other end located inside the external pin hole. This hydraulic cylinder flange connection structure simplifies the machining of the flange and cylinder barrel, facilitates installation, and does not increase the diameter of the cylinder barrel's front end. The cross-sectional shapes of the positioning step, outer annular groove, and inner chamfer are easy to machine and facilitate assembly. The flange and cylinder barrel are connected by the anti-rotation pin, providing good anti-rotation performance and convenient assembly. However, this hydraulic cylinder flange connection structure still does not solve the defect of the flange's outer circular plane not being parallel to the end cover's outer circular plane. Utility Model Content

[0004] To improve the sealing performance of the hydraulic cylinder and solve the defect of cylinder flange interference in the assembly and positioning of ultra-long valve groups, the technical solution adopted by this utility model is: a hydraulic cylinder with no gap between the flange and the end cover, including a cylinder, an upper end cover, a lower end cover, a pair of cylinder flanges and a pair of cylinder retaining rings. The cylinder retaining rings are adjustablely arranged inside the cylinder flanges. The cylinder flanges are threadedly connected to both ends of the cylinder through the cylinder retaining rings. One end of the cylinder flange is bolted to the upper end cover, and the other end of the cylinder flange is bolted to the lower end cover.

[0005] The inner end face of the upper end cover and the inner end face of the lower end cover are respectively fitted to the inner end face of the corresponding cylinder flange.

[0006] Based on the above, in order to facilitate the adjustment of the screwing depth of the cylinder retainer ring on the cylinder, a countersunk hole is provided on the outer end face of the cylinder retainer ring to facilitate the rotation of the cylinder retainer ring.

[0007] Based on the above, in order to prevent the cylinder retaining ring from moving axially during use after assembly, the cylinder retaining ring is provided with fastening screws along the radial direction for holding the cylinder retaining ring on the cylinder.

[0008] Based on the above, a stepped hole is provided inside the cylinder flange to accommodate the cylinder retaining ring.

[0009] Based on the above, in order to facilitate the installation of the valve assembly, the top of the upper end cover, the top of the lower end cover, and the top of the pair of cylinder flanges are respectively provided with installation platforms for installing the valve assembly.

[0010] Based on the above, in order to avoid interference, in the assembled state, the top of the mounting platform located on the cylinder flange is not higher than the top of the mounting platform located on the lower end cover.

[0011] Based on the above, in order to improve sealing, the valve assembly is sealed to the mounting platform.

[0012] Based on the above, the inner end face of the upper end cover and the inner end face of the lower end cover are respectively provided with a boss for inserting into the cylinder, and the outer peripheral surface of the boss is sealed to the inner wall of the cylinder.

[0013] Based on the above, a piston rod is also provided inside the cylinder, and a piston is provided on the piston rod, with the piston sealingly engaging with the inner wall of the cylinder.

[0014] This utility model has substantial features and advancements compared to existing technologies. Specifically, the flange and end cover alignment cylinder provided by this utility model involves threading the outer surface of the cylinder barrel to a cylinder barrel retaining ring, which is then positioned on the cylinder barrel with screws. The cylinder barrel flange is fitted onto the cylinder barrel, with the inner step of the cylinder barrel flange fitting against the end face of the cylinder barrel retaining ring and engaging with the outer surface of the cylinder barrel retaining ring. The right end face of the cylinder barrel flange fits against the lower end cover, and the lower end cover has a stepped end face that fits against the cylinder barrel and cylinder barrel flange. The plane of the outer surface of the lower end cover is parallel to the plane of the outer surface of the cylinder barrel flange, and the valve assembly is connected to the lower end cover using hexagonal screws. This presses the cylinder barrel flange and the lower end cover under the sealing surface of the valve assembly, thereby ensuring a gapless fit between the cylinder flange and the upper and lower end covers, thus improving the cylinder's sealing performance.

[0015] Furthermore, by adjusting the position of the cylinder retaining ring during assembly, it can be ensured that the end cover face fits snugly against the flange face and the cylinder face without gaps, thus avoiding a reduction in the design strength and stability of the hydraulic cylinder due to gaps. In addition, by freely rotating the flange, the outer plane of the flange is made flush with the outer plane of the end cover, avoiding interference with the assembly and positioning defects of the ultra-long valve group. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the flange and end cover alignment cylinder provided by this utility model.

[0017] Figure 2 This is a schematic cross-sectional view of the flange and end cap alignment cylinder provided by this utility model.

[0018] Figure 3 This is a partial structural diagram of the flange and end cap alignment cylinder provided by this utility model.

[0019] Figure 4 and Figure 5 This is a schematic diagram of the cylinder structure in the flange and end cap gapless alignment oil cylinder provided by this utility model.

[0020] Figure 6 This is a schematic diagram of the lower end cover structure in the flange and end cover gapless alignment cylinder provided by this utility model.

[0021] In the diagram: 1. Upper end cap; 2. Piston rod; 3. Cylinder; 4. Piston; 5. First sealing ring; 6. Sealing retainer ring; 7. Lower end cap; 8. First hex bolt; 9. Valve assembly; 10. Second sealing ring; 11. Fastening screw; 12. Cylinder retainer ring; 13. Cylinder flange; 14. Fluid inlet assembly; 15. Second hex bolt; 16. Mounting platform; 17. Countersunk hole. Detailed Implementation

[0022] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0023] Example 1

[0024] This embodiment provides a hydraulic cylinder for seamless alignment of the flange and end cover, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the system includes a cylinder barrel 3, an upper end cover 1, a lower end cover 7, a pair of cylinder barrel flanges 13, and a pair of cylinder barrel retaining rings 12. The cylinder barrel retaining rings 12 are adjustablely disposed within the cylinder barrel flanges 13, and the cylinder barrel flanges 13 are threadedly connected to both ends of the cylinder barrel 3 via the cylinder barrel retaining rings 12. One end of the cylinder barrel flange 13 is bolted to the upper end cover 1, and the other end of the cylinder barrel flange 13 is bolted to the lower end cover 7.

[0025] The inner end face of the upper end cover 1 and the inner end face of the lower end cover 7 are respectively fitted to the inner end face of the corresponding cylinder flange 13.

[0026] To facilitate the installation of valve assembly 9, mounting platforms 16 for installing valve assembly 9 are respectively provided on the top of the upper end cover 1, the top of the lower end cover 7, and the top of the pair of cylinder flanges 13. A fluid passage pipe assembly 14 is connected to valve assembly 9.

[0027] To avoid interference, in the assembled state, the top of the mounting platform 16 located on the cylinder flange 13 is not higher than the top of the mounting platform 16 located on the lower end cover 7. To improve sealing, the valve assembly 9 is sealed to the mounting platform 16.

[0028] In this embodiment, a piston rod 2 is also provided inside the cylinder 3, and a piston 4 is provided on the piston rod 2. The piston 4 is sealed to the inner wall of the cylinder 3.

[0029] Example 2

[0030] This embodiment provides a flange and end cap alignment cylinder with no gap. The main difference from Embodiment 1 is that, in this embodiment, to facilitate adjustment of the screw depth of the cylinder retaining ring 12 on the cylinder 3, a pair of countersunk holes 17 are provided on the outer end face of the cylinder retaining ring 12 to facilitate rotation of the cylinder retaining ring 12. To prevent axial movement of the cylinder retaining ring 12 during use after assembly, fastening screws 11 are provided radially on the cylinder retaining ring 12 to hold the cylinder retaining ring 12 on the cylinder 3.

[0031] Example 3

[0032] This embodiment provides a flange and end cap aligned cylinder without gaps. The main difference from Embodiment 1 is that in this embodiment, the cylinder flange 13 has a stepped hole inside for accommodating the cylinder retaining ring 12. The inner end face of the upper end cap 1 and the inner end face of the lower end cap 7 are respectively provided with bosses for inserting into the cylinder 3, and the outer peripheral surface of the bosses is in a sealing fit with the inner wall of the cylinder 3.

[0033] The cylinder barrel has an external thread at the end of its outer cylindrical surface. The length of the external thread is not less than the width of the cylinder barrel retaining ring 12. This allows the cylinder barrel flange 13 to be flush with the cylinder barrel 3 end face by adjusting the screw depth of the cylinder barrel retaining ring 12 during assembly.

[0034] Specifically, two cylindrical holes for installing fastening screws 11 are evenly distributed radially on the external thread of the cylinder. These cylindrical holes can be drilled after the position is determined by the cylinder retaining ring, and then the fastening screws 11 are installed, which can prevent the cylinder retaining ring from moving axially during the use of the hydraulic cylinder.

[0035] A hole is drilled at the center of the left end face of the lower end cover 7, intersecting with the hole drilled on the mounting platform at the top of the lower end cover, serving as the inlet and outlet oil passage for the rodless chamber of the hydraulic cylinder. Sealing grooves are respectively provided on the outer circumference of the bosses on the upper end cover 1 and the lower end cover 7, with a first sealing ring 5 and a sealing retaining ring 6 placed within the sealing grooves. Four screw holes are provided on the mounting platform 16 at the top of the lower end cover 7, used to fix the valve assembly 9 to the lower end cover 7 using four first hexagon socket bolts 8, and to press the second sealing ring 10 for sealing. Six countersunk holes are evenly arranged along the axial direction on one side end face of the lower end cover 7, used to connect the lower end cover 7 to one of the cylinder flanges 13 using six second hexagon socket bolts 15 during assembly. The length of the valve assembly is not less than the width of the mounting platform on the lower end cover. The lower surface of the valve assembly has a fluid passage hole and a sealing groove, with four countersunk holes around the fluid passage hole, used to fix the valve assembly to the lower end cover using four hexagon socket bolts, and to press the second sealing ring for sealing during assembly.

[0036] The inner surface of the cylinder retaining ring is provided with internal threads, and two threaded through holes are provided evenly distributed in the radial direction. The threaded through holes are used to install screws.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A flange and end cover alignment cylinder with zero clearance, comprising a cylinder barrel, an upper end cover, a lower end cover, a pair of cylinder barrel flanges, and a pair of cylinder barrel retaining rings, characterized in that: The cylinder retaining ring is adjustablely disposed inside the cylinder flange. The cylinder flange is threadedly connected to both ends of the cylinder through the cylinder retaining ring. One end of the cylinder flange is bolted to the upper end cap, and the other end of the cylinder flange is bolted to the lower end cap. The inner end face of the upper end cover and the inner end face of the lower end cover are respectively fitted to the inner end face of the corresponding cylinder flange.

2. The flange and end cover gapless alignment cylinder according to claim 1, characterized in that: The outer end face of the cylinder retaining ring is provided with a countersunk hole to facilitate the rotation of the cylinder retaining ring.

3. The flange and end cover gapless alignment cylinder according to claim 1 or 2, characterized in that: The cylinder retaining ring is provided with fastening screws along the radial direction for holding the cylinder retaining ring on the cylinder.

4. The flange and end cover gapless alignment cylinder according to claim 1, characterized in that: The cylinder flange has a stepped hole inside for accommodating the cylinder retaining ring.

5. The flange and end cover gapless alignment cylinder according to claim 1, 2, or 4, characterized in that: The top of the upper end cover, the top of the lower end cover, and the top of the pair of cylinder flanges are respectively provided with mounting platforms for installing valve assemblies.

6. The flange and end cover gapless alignment cylinder according to claim 5, characterized in that: In the assembled state, the top of the mounting platform located on the cylinder flange is not higher than the top of the mounting platform located on the lower end cover.

7. The flange and end cover gapless alignment cylinder according to claim 6, characterized in that: The valve assembly is sealed to the mounting platform.

8. The flange and end cover gapless alignment cylinder according to claim 1, characterized in that: The inner end face of the upper end cover and the inner end face of the lower end cover are respectively provided with bosses that are inserted into the cylinder, and the outer peripheral surface of the bosses is sealed to the inner wall of the cylinder.

9. The flange and end cover gapless alignment cylinder according to claim 1, 2, 4, or 8, characterized in that: The cylinder is also equipped with a piston rod, and a piston is mounted on the piston rod. The piston is in a sealing fit with the inner wall of the cylinder.

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