A piston rod seal structure

Abstract

The utility model provides a kind of piston rod sealing structure, including shaft sleeve body, external guide, small shaft sleeve and internal guide, through hole is equipped in shaft sleeve body, outer end counterbore and inner end counterbore, piston rod is installed in through hole and is penetrated. External guide and internal guide are respectively installed in two end counterbores, realize sealing and guide;Small shaft sleeve is installed in outer end counterbore bottom, provides lubrication and sealing for piston rod. Shaft sleeve body is equipped with outer ring portion and is equipped with sealing ring, further include external end cap and internal end cap for fixed component. The structure solves the displacement and angle offset problem of piston rod under large stroke, improves installation accuracy and sealing reliability, applicable to vacuum equipment.

Description

Technical Field

[0001] This utility model relates to the field of piston rod sealing technology, specifically a piston rod sealing structure. Background Technology

[0002] In mechanical equipment, cylinders are commonly used actuators, consisting of a cylinder body, piston, piston rod, and sealing rings. For vacuum equipment, the cylinder body is usually mounted outside the vacuum chamber, and the piston rod controls the movement of the driven components inside the vacuum chamber. Because the piston rod connects the inside and outside of the vacuum chamber, the connection point must be sealed.

[0003] The following problems exist with the piston rod sealing structure on the vacuum chamber: For driven components with large strokes, the piston rod displacement is significant. If a copper sleeve is used to limit the movement of the piston rod axially using a cylinder or other driving component, assembly tolerances exist between the piston rod and the sealing component. Therefore, there will be a significant positional offset between the theoretical and actual operating positions of the driven component. Simultaneously, there is an error in the vertical direction between the piston rod and the driven component, resulting in an angular offset between the theoretical and actual operating positions. With a copper sleeve fixing the piston rod at one end, significant displacement and angular offsets are easily generated during installation, posing a risk of leakage to the sealing strip or sealing ring. Utility Model Content

[0004] To address the aforementioned technical shortcomings, the purpose of this utility model is to provide a piston rod sealing structure that solves the problem of piston rod displacement and angular offset under large stroke, thereby improving installation accuracy and sealing reliability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A piston rod sealing structure includes a bushing body, an outer guide member, a small bushing, and an inner guide member. The bushing body has a through hole, an outer countersunk hole, and an inner countersunk hole along its axial direction, with the outer and inner countersunk holes located at opposite ends. The piston rod is installed in the through hole, with both ends extending outwards through the outer and inner countersunk holes, respectively. The outer guide member is installed in the outer countersunk hole, and the inner guide member is installed in the inner countersunk hole. The outer and inner guide members are fitted onto the piston rod for sealing and guiding the piston rod. The small bushing is installed at the bottom of the outer countersunk hole and fitted onto the piston rod for sealing and lubrication of the piston rod.

[0006] Preferably, the cross-sectional shape of the small bushing is I-shaped; both the outer and inner sides of the small bushing are provided with annular grooves, the axis of the annular grooves coincides with the axis of the small bushings, and the annular grooves are used to store lubricating medium.

[0007] Preferably, a sealing ring is installed in the countersunk hole at the outer end; two sealing rings are configured and symmetrically arranged at both ends of the small bushing; the sealing rings are sleeved on the piston rod.

[0008] Preferably, the external guide includes a bushing retaining ring and an outer guide bushing; the bushing retaining ring is installed in the outer end countersunk hole; the outer guide bushing is installed inside the bushing retaining ring; and the outer guide bushing is sleeved on the piston rod.

[0009] Preferably, a positioning ring is integrally provided at one end of the bushing retaining ring near the small bushing; the inner diameter of the positioning ring is larger than the outer diameter of the piston rod and smaller than the outer diameter of the outer guide bushing.

[0010] Preferably, it also includes an external end cap; the external end cap is sleeved and installed on the piston rod, abutting against one side of the external guide, and fixing the external guide in the external countersunk hole.

[0011] Preferably, the internal guide includes an inner guide bushing and a spacer; the inner guide bushing is installed at the bottom of the inner end countersunk hole; the spacer is abutted against the outer side of the inner guide bushing; the axis of the inner guide bushing and the axis of the spacer are in the same straight line.

[0012] Preferably, the internal guide further includes a dustproof sealing ring; the dustproof sealing ring is abutted against the outer side of the partition; the axis of the dustproof sealing ring and the axis of the partition are in the same straight line.

[0013] Preferably, it also includes an inner end cap; the inner end cap is sleeved on the piston rod and abuts against one side of the inner guide, fixing the inner guide in the inner countersunk hole.

[0014] Preferably, the bushing body is integrally provided with an outer ring portion; the bushing body is installed on the wall of the vacuum chamber, the outer ring portion abuts against the outer side of the vacuum chamber wall, the outer end countersunk hole is located on the outer side of the vacuum chamber wall, and the inner end countersunk hole is located on the inner side of the vacuum chamber wall; a plurality of sealing rings are installed on the end face of the outer ring portion that fits against the vacuum chamber wall.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: By setting up a bidirectional guiding structure with external and internal guide components, a double-limiting system is formed for the piston rod, effectively limiting the displacement and angular deviation of the piston rod under large strokes, significantly improving installation accuracy, and fundamentally ensuring the sealing reliability of the sealing components. The small bushing adopts an I-shaped structure with an annular groove, which can stably store the lubricating medium, continuously provide lubrication for the piston rod, reduce frictional loss during movement, and extend the overall service life of the structure. The external and internal end caps respectively axially press and fix the guide components on the corresponding sides, preventing the components from loosening or shifting during piston rod movement, ensuring the continuous effectiveness of sealing and guiding functions. The dustproof sealing ring in the internal guide component can effectively prevent external dust and contaminants from entering the structure, preventing impurities from affecting guiding accuracy and sealing effect, and protecting internal components from contamination and damage. The outer ring of the bushing body increases the contact area with the vacuum chamber wall, and together with the sealing ring, achieves a reliable seal between the bushing body and the vacuum chamber wall, effectively preventing leakage of the vacuum environment inside the vacuum chamber. This improves smooth movement and further enhances the stability and durability of the structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] in: 1. Piston rod; 2. Bushing retaining ring; 3. Outer guide bushing; 4. Outer ring; 5. Sealing ring; 6. Bushing body; 7. Spacer; 8. Dustproof sealing ring; 9. Inner end cap; 10. Inner guide bushing; 11. Vacuum chamber wall; 12. Inner end countersunk hole; 13. Outer end countersunk hole; 14. Small bushing; 15. Outer end cap; 16. Sealing ring. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] like Figure 1As shown, a piston rod sealing structure includes a bushing body 6, an external guide, a small bushing 14, and an internal guide. The bushing body 6 has a through hole, an outer countersunk hole 13, and an inner countersunk hole 12 along its axial direction, with the outer countersunk hole 13 and inner countersunk hole 12 located at opposite ends of the bushing body 6. A piston rod 1 is installed in the through hole, with both ends extending outwards through the outer countersunk hole 13 and inner countersunk hole 12, respectively. The external guide is installed in the outer countersunk hole 13, and the internal guide is installed in the inner countersunk hole 12. The external and internal guides are fitted onto the piston rod 1 for sealing and guiding the piston rod 1. The small bushing 14 is installed at the bottom of the outer countersunk hole 13 and fitted onto the piston rod 1 for sealing and lubrication. This structure achieves stable through-mounting of the piston rod 1 inside and outside the vacuum chamber wall 11. Through the cooperation of the bidirectional guide and the small bushing 14, it balances sealing performance, guiding accuracy, and lubrication, solving the problems of offset and leakage under large strokes.

[0020] In this embodiment, the cross-sectional shape of the small bushing 14 is I-shaped; both the outer and inner surfaces of the small bushing 14 are provided with annular grooves, the axis of which coincides with the axis of the small bushing 14, and the annular grooves are used to store lubricating medium. The I-shaped structure makes the small bushing 14 more stable in installation and positioning, and the annular grooves provide dedicated storage space for the lubricating medium, extending the lubrication cycle, reducing wear between the piston rod 1 and the bushing, and improving the service life of the structure.

[0021] In this embodiment, a sealing ring 16 is installed inside the outer countersunk hole 13; two sealing rings 16 are configured and symmetrically arranged at both ends of the small bushing 14; the sealing rings 16 are sleeved on the piston rod 1. The two sealing rings 16 arranged at both ends of the small bushing 14 seal the outer area of ​​the piston rod 1 to prevent air leakage.

[0022] In this embodiment, the external guide component includes a bushing retaining ring 2 and an outer guide bushing 3. The bushing retaining ring 2 is installed in the outer end countersunk hole 13. The outer guide bushing 3 is installed inside the bushing retaining ring 2. The outer guide bushing 3 is sleeved on the piston rod 1. The bushing retaining ring 2 provides a stable mounting base for the outer guide bushing 3. The outer guide bushing 3 directly contacts and guides the piston rod 1, ensuring the guiding accuracy and sealing reliability on the outer side.

[0023] In this embodiment, a positioning ring is integrally provided at one end of the bushing retaining ring 2 near the small bushing 14; the inner diameter of the positioning ring is larger than the outer diameter of the piston rod 1 and smaller than the outer diameter of the outer guide bushing 3. The positioning ring precisely restricts the installation position of the outer guide bushing 3, preventing its axial displacement or radial offset, ensuring the coaxiality of the outer guide bushing 3 and the piston rod 1, and improving guiding stability.

[0024] In this embodiment, an external end cap 15 is also included. The external end cap 15 is sleeved on the piston rod 1 and abuts against one side of the external guide, fixing the external guide in the outer end countersunk hole 13. The external end cap 15 is axially pressed towards the outer end countersunk hole 13 by a fastening structure, ensuring that the external guide and the small bushing 14 do not move arbitrarily. The axial pressing force fixes the overall position of the external guide, preventing it from loosening or shifting during the movement of the piston rod 1, and ensuring that the external sealing and guiding functions remain effective.

[0025] In this embodiment, the internal guide includes an inner guide bushing 10 and a spacer 7. The inner guide bushing 10 is installed at the bottom of the inner countersunk hole 12. The spacer 7 is abutted against the outer side of the inner guide bushing 10. The axis of the inner guide bushing 10 and the axis of the spacer 7 are in the same straight line. The inner guide bushing 10 provides precise guidance for the inner side of the piston rod 1, and the spacer 7 provides axial restraint to ensure the coaxiality and stability of the inner guide and avoid angular deviation.

[0026] In this embodiment, the internal guide also includes a dustproof sealing ring 8; the dustproof sealing ring 8 is abutted against the outer side of the partition 7; the axis of the dustproof sealing ring 8 and the axis of the partition 7 are in the same straight line. The dustproof sealing ring 8 prevents external dust and contaminants from entering the interior of the sealing structure, avoiding impurities from affecting the guiding accuracy and sealing effect, and protecting internal components from contamination and damage.

[0027] In this embodiment, an inner end cap 9 is also included. The inner end cap 9 is sleeved on the piston rod 1 and abuts against one side of the inner guide, fixing the inner guide in the inner countersunk hole 12. The inner end cap 9 is axially pressed towards the inner countersunk hole 12 by a fastening structure to ensure that the inner guide does not move arbitrarily. The overall structure that presses and fixes the inner guide prevents it from loosening and shifting in the internal environment of the vacuum chamber 11, ensuring the long-term reliability of the inner guiding and sealing functions.

[0028] In this embodiment, an outer ring portion 4 is integrally formed on the outside of the bushing body 6. The bushing body 6 is mounted on the vacuum chamber wall 11, with the outer ring portion 4 abutting against the outer side of the vacuum chamber wall 11. The outer end countersunk hole 13 is located on the outer side of the vacuum chamber wall 11, and the inner end countersunk hole 12 is located on the inner side of the vacuum chamber wall 11. A plurality of sealing rings 5 ​​are installed on the end face of the outer ring portion 4 that fits against the vacuum chamber wall 11. The outer ring portion 4 increases the contact area between the bushing body 6 and the vacuum chamber wall 11, and together with the sealing rings 5, achieves a sealed connection between the two, preventing leakage of the vacuum environment inside the vacuum chamber 11, while providing a stable mounting support for the bushing body 6.

[0029] In this embodiment, the outer guide bushing 3 and the inner guide bushing 10 are self-lubricating bushings or copper bushings; the small bushing 14 is a copper bushing. The self-lubricating bushing or copper bushing has good wear resistance and self-lubricating properties, and the copper bushing has excellent thermal conductivity and wear resistance, reducing frictional resistance during the guiding process, improving the smoothness of piston rod 1 movement, and extending the service life of the components.

[0030] Working principle The bushing body 6 is sealed and fixed to the vacuum chamber wall 11 via the outer ring 4. The piston rod 1 passes through the through hole of the bushing body 6 and extends to both the inner and outer sides. The external guide and the internal guide are respectively installed in the countersunk holes at both ends of the bushing body 6, forming a bidirectional guide and sealing protection for the piston rod 1. The small bushing 14 stores the lubricating medium through the annular groove, reducing frictional loss when the piston rod 1 moves axially. The external end cap 15 and the internal end cap 9 respectively press the guide components on the corresponding sides to ensure the overall structure is stable and to prevent the sealing components from shifting. Ultimately, this achieves the requirement that the piston rod 1 has precise guidance, reliable sealing, and long-term lubrication during large stroke movements.

Claims

1. A piston rod sealing structure, characterized in that, The assembly includes a bushing body (6), an external guide, a small bushing (14), and an internal guide. The bushing body (6) has a through hole, an outer countersunk hole (13), and an inner countersunk hole (12) along the axial direction. The outer countersunk hole (13) and the inner countersunk hole (12) are respectively located at both ends of the bushing body (6). The piston rod (1) is installed in the through hole, and its two ends extend outward through the outer countersunk hole (13) and the inner countersunk hole (12), respectively. The external guide is installed in the outer countersunk hole (13), and the internal guide is installed in the inner countersunk hole (12). The external guide and the internal guide are sleeved on the piston rod (1) for sealing and guiding the piston rod (1). The small bushing (14) is installed at the bottom of the outer countersunk hole (13) and sleeved on the piston rod (1) for sealing and providing lubrication for the piston rod (1).

2. The piston rod sealing structure as described in claim 1, characterized in that, The cross-sectional shape of the small bushing (14) is I-shaped; both the outer and inner sides of the small bushing (14) are provided with annular grooves, the axis of the annular grooves coincides with the axis of the small bushing (14), and the annular grooves are used to store lubricating medium.

3. The piston rod sealing structure as described in claim 1, characterized in that, A sealing ring (16) is installed in the outer end countersunk hole (13); two sealing rings (16) are configured and symmetrically arranged at both ends of the small bushing (14); the sealing rings (16) are sleeved on the piston rod (1).

4. The piston rod sealing structure as described in claim 1, characterized in that, The external guide includes a bushing retaining ring (2) and an outer guide bushing (3); the bushing retaining ring (2) is installed in the outer end countersunk hole (13); the outer guide bushing (3) is installed inside the bushing retaining ring (2); the outer guide bushing (3) is sleeved on the piston rod (1).

5. A piston rod sealing structure as described in claim 4, characterized in that, The bushing retaining ring (2) has a positioning ring integrally provided at one end near the small bushing (14); the inner diameter of the positioning ring is larger than the outer diameter of the piston rod (1) and smaller than the outer diameter of the outer guide bushing (3).

6. The piston rod sealing structure as described in claim 1, characterized in that, It also includes an external end cap (15); the external end cap (15) is fitted onto the piston rod (1) and abuts against one side of the external guide, fixing the external guide in the external countersunk hole (13).

7. The piston rod sealing structure as described in claim 1, characterized in that, The internal guide includes an inner guide bushing (10) and a partition (7); the inner guide bushing (10) is installed at the bottom of the inner end countersunk hole (12); the partition (7) is installed against the outside of the inner guide bushing (10); the axis of the inner guide bushing (10) and the axis of the partition (7) are in the same straight line.

8. The piston rod sealing structure as described in claim 7, characterized in that, The internal guide also includes a dustproof sealing ring (8); the dustproof sealing ring (8) is abutted against the outside of the partition (7); the axis of the dustproof sealing ring (8) and the axis of the partition (7) are in the same straight line.

9. A piston rod sealing structure as described in claim 1, characterized in that, It also includes an inner end cap (9); the inner end cap (9) is fitted onto the piston rod (1) and abuts against one side of the inner guide, fixing the inner guide in the inner end countersunk hole (12).

10. A piston rod sealing structure as described in any one of claims 1 to 9, characterized in that, The bushing body (6) is integrally provided with an outer ring (4); the bushing body (6) is installed on the vacuum chamber wall (11), the outer ring (4) abuts against the outer side of the vacuum chamber wall (11), the outer end countersunk hole (13) is located on the outer side of the vacuum chamber wall (11), and the inner end countersunk hole (12) is located on the inner side of the vacuum chamber wall (11); a number of sealing rings (5) are installed on the end face of the outer ring (4) that fits against the vacuum chamber wall (11).

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