Multistage sealing packing device

Abstract

The utility model discloses a multi-stage sealing packing device, which relates to the technical field of sealing packing and comprises a lip-shaped packing, and the lip-shaped packing is an annular packing formed by rotating a section unit around a packing central shaft; an expansion upper top end is arranged at the top of the section unit, an inner groove is formed in the bottom of the section of the sealing packing to divide an inner lip and an outer lip, and an expansion groove is formed in the top of the inner groove. The expansion groove can improve the expansion performance of the inner lip opening and the outer lip opening, and meanwhile the expansion upper top end can enter the expansion groove to increase the attaching force between the lip-shaped packing during compression.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing packing, in particular to a multi-stage sealing packing device. Background Art

[0002] At present, the packing used in the rod seal of oilfield pumping units is mainly spiral packing, which has a rectangular or trapezoidal cross-section and an overall structure of a wound column with a through hole in the center. When in use, the spiral packing is placed in the rod sealer and sealed by tightening the pressure cover on the upper end of the sealer. Although the spiral packing has a simple structure and is inexpensive, it wears severely during use and is prone to seal failure, causing oil leakage. It has a short effective service life and requires frequent replacement, which reduces the production time of the oil well. From the perspective of the relationship between structure and sealing effect, the existing spiral packing is an integral structure, and a step-by-step sealing effect cannot be formed between the winding surfaces. At the same time, since the packing forms a surface seal between the packing and the rod and between the packing and the sealer pipe wall, when the rod is offset, the seal fails due to severe wear.

[0003] Publication No.: CN118774661A discloses a reverse spiral shaft sealing structure of a wellhead sealer, comprising a polished rod, a packing sealing assembly, a valve body, a middle sealing body, a left reverse spiral sealing assembly, and a right reverse spiral sealing assembly. The packing sealing assembly is provided on the upper part of the polished rod, and the valve body is sleeved on the outer side of the middle part of the polished rod. The left and right sides of the middle part of the valve body are provided with middle sealing bodies capable of sealing the corresponding positions of the polished rod. The outer ends of the two sets of middle sealing bodies are respectively connected to the left reverse spiral sealing assembly and the right reverse spiral sealing assembly.

[0004] Announcement No.: CN204754852U, discloses a wellhead flexible polished rod sealing device, including: a sealing ring and a sealing ring box, wherein the sealing ring includes a soft sealing ring sleeved on the outside of the flexible polished rod and a metal expansion ring located at the bottom of the soft sealing ring, the lower part of the soft sealing ring is provided with a "V"-shaped groove, the upper part of the metal expansion ring is provided with a ridge that cooperates with the "V"-shaped groove, the sealing ring box is sleeved on the outside of the flexible polished rod, wherein the inner wall of the sealing ring box is provided with an annular groove, and the annular groove cooperates with the sealing ring.

[0005] Announcement No.: CN218934365U discloses an oil rod sealing packing box and fault monitoring system, including a polished rod sealing box, the bottom of which is fixedly connected to an oil pipe connector by bolts, and the interior of the polished rod sealing box is provided with several layers of polished rod sealing rings stacked one above the other. The top of the polished rod sealing box is provided with a sealing ring pressing cylinder, which indirectly presses the polished rod sealing ring through a polished rod sealing pressure ring gasket.

[0006] The annular packings in the above-mentioned prior art are different from the lip-type packing of this patent. The lip-type packing of this patent has better sealing performance, better compression and expansion performance, and longer service life.

[0007] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from those of the present utility model. Regarding the more technical features, technical problems to be solved and the beneficial effects of the present utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0008] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a multi-stage sealing packing device.

[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0010] A multi-stage sealing packing device includes a lip-shaped packing, which is an annular packing formed by rotating a cross-sectional unit around the central axis of the packing; an expanded upper top head is provided at the top of the cross-sectional unit, an inner groove is provided at the bottom of the sealing packing cross-section to divide the inner lip and the outer lip, and an expansion groove is provided at the top of the inner groove.

[0011] Furthermore, the expansion groove is a straight groove, and the expansion upper top end is a trapezoidal end end.

[0012] Furthermore, the inner groove is an isosceles triangle, the trapezoidal end is an isosceles trapezoid, and the inner groove is located on the center line of the cross-sectional unit.

[0013] Preferably, the isosceles angle between the trapezoidal end of the lip-shaped packing and the isosceles angle of the inner groove ranges from 60° to 120°.

[0014] Preferably, the upper base width of the trapezoidal end is 1.1-1.4 times the width of the straight groove at the top of the inner groove, and the height of the straight groove is 2.5-4 times the width of the straight groove.

[0015] Furthermore, the inner wall and the outer wall of the lip-shaped packing are both conical surfaces. The inner wall of the lip-shaped packing can be extended to form an inner cone with a cone angle facing downward, and the outer wall of the lip-shaped packing can be extended to form an outer cone with a cone angle facing upward.

[0016] Preferably, the inner cone angle is the same as the outer cone angle, both of which are 6°-15°.

[0017] Furthermore, at least two lip-shaped packings are provided, and the inner groove of the upper lip-shaped packing and the expanded upper top end of the lower lip-shaped packing are nested with each other to form a lip-shaped packing combination.

[0018] Furthermore, it also includes a wing-type packing, wherein the wing-type packing is provided with a half-hole groove, the wing-type packing is provided with a clamping groove on both sides of the half-hole groove, and a metal nut is embedded in the end of the wing-type packing away from the polished rod;

[0019] Specifically, two wing-type packings are spliced ​​together to form a double-petal wing-type packing, two half-hole grooves are spliced ​​together to form a polished rod hole, and the slot is used for the mutual nesting of the two wing-type packings.

[0020] Furthermore, the upper end of the wing-type packing is provided with a sunken groove, and the lower end of the lip-type packing assembly is installed in the sunken groove provided at the upper end of the wing-type packing.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The utility model uses highly wear-resistant self-lubricating nitrile rubber lip-type packing and wing-type packing as basic components. Through the reasonable combination of the packings of the two structures, the line seal formed by the lip-type packing, the polished rod and the sealer wall and the longitudinal self-tightening effect between the multiple lip-type packings are used to achieve a step-by-step sealing effect. The lateral effect of the wing-type packing and the polished rod is used to straighten the polished rod and thus reduce the interface friction and wear between the polished rod and the packing, forming a multi-stage sealing effect. The utility model can effectively solve the sealing problem of the wellhead of the pumping unit, increase the effective service life of the packing, reduce the labor hours caused by replacing the packing, and improve the production time rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of the multi-stage sealing packing device of the utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the wing-type packing in the utility model;

[0025] Figure 3 It is a structural diagram of the lip-shaped packing in the utility model.

[0026] In the figure: 11, lip-type packing combination; 12, wing-type packing; 13, polished rod; 14, tapered cavity; 21, countersunk groove; 22, clamping groove; 23, metal nut; 31, inner lip; 32, outer lip; 33, inner groove; 34, trapezoidal end; 35, straight groove. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example 1:

[0029] See also Figure 1The multi-stage sealing packing device provided by the present invention includes a lip-shaped packing assembly 11 and a flap-shaped wing-shaped packing. When in use, the lip-shaped packing assembly 11 and the flap-shaped wing-shaped packing are sleeved on the polished rod 13. The multi-stage sealing packing device can significantly improve the sealing effect and extend the service life.

[0030] like Figure 3 As shown, the lip-type packing combination 11 includes a lip-type packing, which is an annular packing formed by rotating a cross-sectional unit around the central axis of the packing. A trapezoidal end head 34 is provided on the top of the cross-sectional unit. An inner groove 33 is provided at the bottom of the sealing packing cross-section to divide the inner lip 31 and the outer lip 32. A straight groove 35 is provided on the top of the inner groove 33. The straight groove 35 can improve the expansion performance of the inner lip 31 and the outer lip 32, and at the same time, the trapezoidal end head 34 can enter the inner groove during compression to increase the fitting force between the lip-type packings; the inner wall and the outer wall of the lip-type packing are both conical surfaces, and the inner wall of the lip-type packing can be extended to form an inner cone with a cone angle downward, and the outer wall of the lip-type packing can be extended to form an outer cone with a cone angle upward.

[0031] The inner groove 33 of the upper lip packing and the trapezoidal end 34 of the lower lip packing are nested with each other to form a lip packing assembly 11 .

[0032] During use, the edge of the inner lip 31 forms a line seal with the polished rod, while the edge of the outer lip 32 forms a line seal with the sealer wall. This dual seal effectively prevents leakage of the medium. If the inner and outer lips 31, 32 become worn, the inner and outer lips 31, 32 of the lip packing can be expanded outward under pressure by tightening the sealer gland. These lips then adhere tightly to the polished rod and sealer wall, respectively, forming an inner and outer line seal.

[0033] like Figure 2 As shown, the wing packing includes two wing packings 12, which are provided with half-hole grooves. The half-hole grooves are spliced ​​to form a polished rod hole. The wing packing 12 is provided with slots 22 on both sides of the half-hole groove for the mutual nesting combination of the two wing packings 12. A metal nut 23 is embedded in the end of the wing packing 12 away from the polished rod, and the wing packing is fixed in the sealer through a metal fixing unit. When the polished rod is offset, the metal parts at both ends of the sealer are screwed to make the two petals of the wing packing 12 fit tightly against each other, straighten the polished rod, and produce a sealing effect.

[0034] The upper end of the wing-type packing is provided with a sinking groove 21, and the lower end of the lip-type packing assembly 11 is installed in the sinking groove 21 provided at the upper end of the wing-type packing.

[0035] The materials of the wing-type packing and lip-type packing are both nitrile materials.

[0036] During installation, first secure the wing packing 12 to the matching sealer. Then, assemble the lip packing assembly 11 and place it in the sealer, and tighten the sealer gland. The lip packing assembly 11 and wing packing 12, when used in combination, form a multi-stage seal. Combined with the high wear resistance of the self-lubricating nitrile material, this further enhances the sealing effect and extends service life. Specifically, the matching sealer can be the wellhead sealer reverse spiral shaft seal structure disclosed in publication number CN118774661A, with the wing packing 12 replacing the central seal body and the lip packing assembly 11 replacing the packing seal assembly.

[0037] In the sealer, there is a line seal between each lip-shaped packing and the polished rod 13. After the packing is worn, downward pressure is generated by tightening the sealer cover. This longitudinal pressure causes the upper end of the lower lip-shaped packing to generate radial pressure on the lower end of the upper lip-shaped packing. The radial pressure causes the inner lip 31 of the lip-shaped packing to hold the polished rod tightly to form a continuous pre-tightening force, and the outer lip 32 fits tightly with the sealer wall. This action of multiple lip-shaped packings and the polished rod realizes a step-by-step sealing effect, further improving the sealing performance and extending the service life.

[0038] In the sealer, when the polished rod 13 deviates and causes seal failure, lateral pressure is generated by screwing the inverted cone sealing shaft of the sealer, so that the polished rod 13 fits tightly with the center hole of the wing-type packing 12. The wing-type packing 12 improves the sealing performance while straightening the polished rod 13.

[0039] Example 2:

[0040] On the basis of Example 1, in this embodiment, the inner groove 33 is an isosceles triangle, the trapezoidal end 34 is an isosceles trapezoid, and the inner groove 33 is located on the center line of the cross-sectional unit.

[0041] Specifically, the isosceles angle between the trapezoidal end 34 of the lip-shaped packing and the isosceles angle between the inner groove 33 is in the range of 60° to 120°.

[0042] Preferably, the isosceles angle between the trapezoidal end 34 of the lip packing and the inner groove 33 is 90°. At this angle, the lip packings nest more tightly during compression and expansion, achieving optimal sealing performance. If the angle between the trapezoidal end 34 and the inner groove 33 is outside the preferred range, such as 30°, expansion performance will be affected, reducing the sealing effect.

[0043] Specifically, the width of the upper base of the trapezoidal end 34 is 1.1-1.4 times the width of the straight groove 35 at the top of the inner groove 33 , and the height of the straight groove 35 is 2.5-4 times the width of the straight groove 35 .

[0044] Preferably, the upper base width of the trapezoidal end head 34 is 1.2 times the width of the straight groove 35 at the top of the inner groove 33, and the height of the straight groove 35 is 3 times the width of the straight groove 35, so that the trapezoidal end head 34 can be tightly combined with the inner groove 33 during compression, and the inner lip 31 and the outer lip 32 have good expansion performance.

[0045] Specifically, the inner cone angle is the same as the outer cone angle, both of which are 6°-15°.

[0046] Preferably, the inner and outer cone angles are 10°. At this angle, the inner lip and the polished rod, and the outer lip and the sealer wall, have optimal contact pressure, minimizing friction and wear during relative motion and ensuring a continuous seal. When the cone angle is 3°, the resulting high contact pressure can easily cause the inner and outer lips to wear against the polished rod and the sealer wall, respectively, leading to a loss of sealing effectiveness. When the angle is 20°, the contact pressure is low, resulting in a loss of effective sealing.

[0047] Example 3:

[0048] Based on Example 1 or 2, in this embodiment, the upper end of the lip-shaped packing cross section is provided with a trapezoidal shoulder structure, and the lower end is provided with a trapezoidal structure with inner and outer lips to prevent the packings from loosening from each other during operation.

[0049] The trapezoidal end 34 has a trapezoidal upper base width of 1.25 mm, a lower base width of 12.25 mm, and a height of 6.15 mm.

[0050] The cross-sections of the inner lip 31 and the outer lip 32 are also trapezoidal structures, and the thickness of the thinnest parts of the bottoms of the inner lip 31 and the outer lip 32 are both 1.5 mm.

[0051] The width of the upper shoulder of the lip-shaped packing in the present invention, that is, the lower bottom of the trapezoidal end 34, is 12.25 mm, and the width of the lower end, that is, the maximum distance between the inner lip 31 and the outer lip 32, is 15 mm.

[0052] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.

[0053] In this utility model, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.

[0054] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0055] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. Multi-stage sealing packing device, characterized in that: It includes lip-shaped packing, which is an annular packing formed by rotating the cross-section unit around the packing center axis; An expanded upper top end is provided at the top of the cross-section unit, an inner groove is provided at the bottom of the sealing packing cross-section to divide an inner lip and an outer lip, and an expansion groove is provided at the top of the inner groove.

2. The multi-stage sealing packing device according to claim 1, characterized in that: The expanded upper top end is a trapezoidal end, and the expanded groove is a straight groove.

3. The multi-stage sealing packing device according to claim 2, characterized in that: The inner groove is an isosceles triangle, the trapezoidal end is an isosceles trapezoid, and the inner groove is located on the center line of the cross-sectional unit.

4. The multi-stage sealing packing device according to claim 3, characterized in that: The isosceles angle of the trapezoidal end of the lip-shaped packing and the isosceles angle of the inner groove range from 60° to 120°.

5. The multi-stage sealing packing device according to claim 2, characterized in that: The upper base width of the trapezoidal end is 1.1-1.4 times the width of the straight groove at the top of the inner groove, and the height of the straight groove is 2.5-4 times the width of the straight groove.

6. The multi-stage sealing packing device according to claim 1, characterized in that: The inner wall and the outer wall of the lip-shaped packing are both conical surfaces. The inner wall of the lip-shaped packing can be extended to form an inner cone with a cone angle facing downward, and the outer wall of the lip-shaped packing can be extended to form an outer cone with a cone angle facing upward.

7. The multi-stage sealing packing device according to claim 6, characterized in that: The inner cone angle is the same as the outer cone angle, both of which are 6°-15°.

8. The multi-stage sealing packing device according to any one of claims 1 to 7, characterized in that: At least two lip-shaped packings are provided, and the inner groove of the upper lip-shaped packing and the expanded upper top end of the lower lip-shaped packing are nested with each other to form a lip-shaped packing combination.

9. The multi-stage sealing packing device according to claim 8, characterized in that: The wing-type packing is provided with a half-hole groove, the wing-type packing is provided with a clamping groove on both sides of the half-hole groove, and a metal nut is embedded in the end of the wing-type packing away from the polished rod; Two wing-type packings are spliced ​​together to form a double-petal wing-type packing, two half-hole grooves are spliced ​​together to form a polished rod hole, and the slot is used for the mutual nesting of the two wing-type packings.

10. The multi-stage sealing packing device according to claim 9, characterized in that: The upper end of the wing-type packing is provided with a sunken groove, and the lower end of the lip-type packing assembly is installed in the sunken groove provided at the upper end of the wing-type packing.

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