Reciprocating motion self-lubricating head ring

Abstract

The utility model relates to a reciprocating motion self-lubricating head ring which comprises a bottom, an outer wall, a top end, a liquid storage groove, a sand scraping wall and a plunger sealing face. A bottom matching structure matched with the contact surface of the pressure ring is arranged at the front end of the bottom; an outer wall and a plunger sealing face are arranged on the two sides of the bottom respectively. A top end is arranged on one side of the outer wall away from the bottom; a liquid storage tank for separating liquid from hard objects is arranged below the top end; a sand scraping wall used for scraping liquid containing hard objects into the liquid storage tank is arranged between the lower portion of the liquid storage tank and the sealing face of the plunger. According to the utility model, hard objects are prevented from entering the sealing surface of the plunger to tear and erode the head ring; the friction heat is reduced, and the self-lubricating property and the corrosion resistance of the first ring are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the petroleum and natural gas industry assembly manufacturing technical field, and specifically relates to reciprocating motion self-lubricating first ring. BACKGROUND

[0002] The oilfield fracturing (cementing) vehicle is a kind of equipment for oil and gas well production increase, and fracturing is to artificially utilize hydraulic action to make oil and gas layer form cracks in the oil or gas production process, so as to improve the flow environment of oil and gas underground, make the bottom flow condition of oil and gas well, slow down interlayer and improve the movement condition of oil layer, and increase the yield of oil and gas well. The main power source for realizing fracturing effect is high-pressure pump, and high-pressure pump can be said to be the heart of fracturing vehicle, which determines the quality of fracturing (cementing) vehicle. The packing assembly in the liquid end of high-pressure pump is the guarantee of providing effective sealing power, and determines the length of the continuous operation time of fracturing vehicle.

[0003] The local structure of pump liquid end is as shown in Figure 2 The service life of packing assembly is an important indicator of the performance of fracturing pump. With the improvement of fracturing process technology, the working environment of fracturing pump is extremely harsh: the working pressure is extremely high; the fracturing fluid contains a large amount of sand particles with extremely high hardness and other stains; and the fracturing fluid has high acidity, low viscosity and poor self-lubricity; the plunger moves at high speed, and in the working process, the liquid containing impurities first contacts the first ring, and the first ring bears high pressure and impurity scouring, at this time, it is both a sealing ring and a sand scraping ring; the wear and corrosion of the first ring are very serious. In order to improve the wear resistance and corrosion resistance of the first ring in the packing assembly, some methods have been proposed. For example, the material of the first ring of the packing is replaced constantly, and the rubber packing is replaced by HNBR. HNBR has good temperature resistance and chemical corrosion resistance, can effectively reduce the friction coefficient and wear amount, and prolong the service life of the packing, but if the packing assembly has a water leakage problem, most of the time, it is caused by the damage of the first ring of the packing, therefore, the improvement of the first ring is still an urgent need to prolong the service life of the packing.

[0004] The defects of the prior art are as follows:

[0005] 1. Since the first ring of the prior art is a pure rubber product, it has no self-lubricating effect, and is in contact with sand particles for a long time, which will soon be torn and broken to cause water leakage, resulting in a short service life of the packing assembly, which needs to be replaced frequently, increases the cost and risk of operation, and also affects the oil production efficiency.

[0006] 2. Since the first ring of the prior art has R radian at the matching position with the plunger, hard objects in the liquid are easy to be washed into the space between the first ring and the plunger, which causes the water leakage problem caused by the damage of the first ring after the replacement of the first ring material. SUMMARY

[0007] The utility model discloses to the above -mentioned problem provides reciprocating motion self -lubricating first ring, and its purpose is to prevent hard object from entering plunger sealing surface and causes first ring to be torn and erosion, reduces friction heat, improves first ring's self -lubricating and corrosion resistance.

[0008] To solve the above problems, the utility model provides a technical scheme:

[0009] A reciprocating motion self -lubricating first ring, containing bottom, outer wall, top, liquid storage groove, scrape sand wall, plunger sealing surface, wherein:

[0010] The bottom's front end is equipped with the bottom cooperation structure that cooperates with the contact surface of pressure ring, the bottom's both sides are equipped with outer wall and plunger sealing surface respectively, the outer wall's side away from bottom is equipped with top, the top's below is equipped with liquid storage groove for separating liquid and hard object, and the liquid storage groove's below and plunger sealing surface between are equipped with scrape sand wall for scraping the liquid containing hard object into liquid storage groove.

[0011] Preferably, the bottom cooperation structure contains semicircle arc type convex structure and slope face, the semicircle arc type convex structure is equipped with the top of bottom cooperation structure, is positioned for cooperating with the contact surface of pressure ring, and two slope faces are equipped with both sides of semicircle arc type convex structure.

[0012] Preferably, the slope angle of two slope faces is 120 degrees, and the height is 3mm, and the height of semicircle arc type convex structure is 1.8mm.

[0013] Preferably, the liquid storage groove contains hard object separation groove, liquid flow channel, liquid flow buffer area, wherein: the hard object separation groove is the structure that recesses inward, and is used for separating liquid and hard object, the liquid flow channel is equipped between hard object separation groove and scrape sand wall, and the liquid flow buffer area is equipped between hard object separation groove and top.

[0014] Preferably, the height of hard object separation groove is 2.5mm, the height of liquid flow channel is 2mm, and the height of liquid flow buffer area is 2mm.

[0015] Preferably, the scrape sand wall is straight mouth type structure.

[0016] Preferably, the length of scrape sand wall is 4mm.

[0017] Preferably, the plunger sealing surface is outwardly convex circular arc structure.

[0018] Preferably, the radius of circular arc of plunger sealing surface is 9mm, and the height of plunger sealing surface is 11mm.

[0019] Preferably, the surface of the bottom, the liquid storage groove, the sand scraping wall and the plunger sealing surface is treated by fluorine coating process.

[0020] The utility model has the following advantages compared with prior art:

[0021] 1. The hard material separation groove is additionally arranged at the plane of the liquid storage groove, so that the liquid and the hard material are separated, and the hard material is prevented from entering the plunger sealing surface to cause the first ring to be torn and eroded.

[0022] 2. The upper half of the plunger sealing surface is changed from arc shape to straight mouth shape, so that the plunger sealing surface can be tightly matched with the plunger wall, and the quartz sand is prevented from entering the first ring and the plunger to cause the first ring to be torn and eroded.

[0023] 3. The surface in contact with the liquid is treated by fluorine coating, and the fluorine has the advantages of self-lubrication, high temperature resistance and corrosion resistance, so that the friction heat can be reduced, and the self-lubrication and corrosion resistance of the first ring are improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the first ring of prior art;

[0025] Figure 2 It is a schematic view of a sealing packing assembly and liquid flow direction of prior art;

[0026] Figure 3 It is a structural schematic view of the self-lubricating first ring of the utility model;

[0027] Figure 4 It is a schematic view of a sealing packing assembly and liquid flow direction of the utility model.

[0028] Wherein: 1. bottom, 2. outer wall, 3. top end, 4. liquid storage groove, 5. sand scraping wall, 6. plunger sealing surface, 1.1. bottom matching structure, 1.1.1. semicircular convex structure, 1.1.2. slope surface, 4.1. hard material separation groove, 4.2. liquid flow channel, 4.3. liquid flow buffer zone, A1. top cover, A2. first ring, A3. pressure ring, A4. isolation ring, A5. seat ring, A6. packing box, A7. plunger, A8. pump head body, B2. self-lubricating first ring DETAILED DESCRIPTION

[0029] The utility model will be further illustrated in combination with specific embodiments, and it should be understood that these embodiments are only used for illustrating the utility model and are not used for limiting the scope of the utility model, and after reading the utility model, various equivalent modifications of the utility model made by those skilled in the art all fall within the scope defined by the claims attached to the present application.

[0030] As Figure 3 , 4As shown, a reciprocating self-lubricating primary ring comprises a bottom 1, an outer wall 2, a top end 3, a liquid storage groove 4, a sand scraping wall 5, and a plunger sealing surface 6, wherein:

[0031] The front end of the bottom 1 is provided with a bottom matching structure 1.1 matched with the contact surface of the pressure ring A3; the two sides of the bottom 1 are respectively provided with the outer wall 2 and the plunger sealing surface 6; the side of the outer wall 2 away from the bottom 1 is provided with the top end 3; the lower side of the top end 3 is provided with the liquid storage groove 4 for separating liquid and hard objects; the lower side of the liquid storage groove 4 and the plunger sealing surface 6 are provided with the sand scraping wall 5 for scraping the liquid containing hard objects into the liquid storage groove 4.

[0032] It should be noted that the bottom matching structure 1.1 comprises a semicircular arc protruding structure 1.1.1 and a slope surface 1.1.2; the semicircular arc protruding structure 1.1.1 is arranged at the top end of the bottom matching structure 1.1 and is used for matching and positioning with the contact surface of the pressure ring A3; the two slope surfaces 1.1.2 are respectively arranged at the two sides of the semicircular arc protruding structure 1.1.1.

[0033] In this embodiment, the slope angle of the two slope surfaces 1.1.2 is 120 degrees, and the height is 3mm; the height of the semicircular arc protruding structure 1.1.1 is 1.8mm.

[0034] It should be noted that the liquid storage groove 4 comprises a hard object separation groove 4.1, a liquid flow channel 4.2, and a liquid flow buffer area 4.3, wherein: the hard object separation groove 4.1 is an inwardly recessed structure and is used for separating liquid and hard objects. The liquid flow channel 4.2 is arranged between the hard object separation groove 4.1 and the sand scraping wall 5; the liquid flow buffer area 4.3 is arranged between the hard object separation groove 4.1 and the top end 3.

[0035] It should be further noted that, when in operation, the liquid storage groove 4 and the top cover A1 form a space, like a horizontally lying bottle with a small mouth and a large belly. When the liquid containing hard objects is pushed by the sand scraping wall 5, the liquid will enter the liquid flow buffer area 4.3 along the liquid flow channel 4.2. Due to the increase in space, the impact force of the liquid decreases, and heavy hard objects will be separated from light and small impurities. Under the back and forth washing of the liquid, the heavy hard objects will be delayed and will be washed into the hard object separation groove 4.1, achieving the purpose of hard object separation.

[0036] In this embodiment, the height of the hard object separation groove 4.1 is 2.5mm; the height of the liquid flow channel 4.2 is 2mm; and the height of the liquid flow buffer area 4.3 is 2mm.

[0037] It should be noted that the sand scraping wall 5 is a straight mouth structure; the straight mouth structure can be closely matched with the outer wall of the plunger A7, like a windshield wiper for a car, which plays a role in scraping sand to prevent quartz sand from entering between the self-lubricating primary ring B2 and the plunger A7.

[0038] Further, the sand scraping wall 5 and the outer wall of the plunger A7 are tightly matched to form a seamless scraping surface during operation, and the sand scraping wall 5 can scrape the liquid containing hard objects into the liquid storage groove 4 when the plunger A7 moves left and right. The working principle is the same as that of the windshield wiper on the front windshield of a car to scrape water and sundries on the glass.

[0039] In the embodiment, the length of the sand scraping wall 5 is 4 mm.

[0040] It should be noted that the plunger sealing surface 6 is outwardly convex arc-shaped structure. When the packing box A6 is tightened, the self-lubricating primary ring B2 is deformed, and the outer side is tightly attached to the straight mouth and cannot be deformed. Only the plunger sealing surface 6 on the inner side is arc-shaped, like the structure of a half O-shaped sealing ring, which is easy to deform under stress, so that the plunger sealing surface 6 is pressed inwardly and tightly attached to the plunger A7 to form a sealing surface.

[0041] In the embodiment, the radius of the plunger sealing surface 6 is 9 mm, and the height of the plunger sealing surface 6 is 11 mm.

[0042] It should be noted that the surfaces of the bottom 1, the liquid storage groove 4, the sand scraping wall 5, and the plunger sealing surface 6 are treated by fluorine coating process. Fluorine has the advantages of self-lubrication, high temperature resistance, and corrosion resistance, which can reduce frictional heat generation and improve the self-lubrication and corrosion resistance of the self-lubricating primary ring B2. The fluorine-containing material solvent is sprayed on the part of the self-lubricating primary ring B2 in contact with the liquid and the dynamic sealing surface, and the spraying thickness is between 0.04 mm and 0.1 mm. The main purpose is to protect the liquid from corroding the rubber through the fluorine material, while reducing the friction coefficient between the self-lubricating primary ring B2 and the plunger A7, and improving the wear resistance of the self-lubricating primary ring B2.

[0043] It should be noted that, as shown in Figure 1 , 2 In the prior art, the seat ring A5, the isolation ring A4, the pressure ring A3, and the primary ring A2 of the packing assembly are arranged in the order of Figure 2The sequence in the drawing is as follows: the top cover A1 is installed into the pump head body A8, the packing box A6 is connected with the pump head body A8, and then the plunger A7 is installed, so that an annular cavity is formed between the pump head body A8 and the plunger A7. The first ring A2 is compressed by rotating the packing box A6 to the depth, so that the outer wall of the first ring A2 is in contact with the packing box A6, and the inner wall is in close contact with the plunger A7, thereby forming a sealed space between the pump head body A8 and the plunger A7. During operation, the bottom 1, the outer wall 2 and the top end 3 of the first ring A2 are respectively in static sealing cooperation with other accessories; the liquid storage groove 4 of the first ring A2 is in contact with the corrosive liquid, and the plunger sealing surface 5 of the first ring A2 is in close contact with the plunger A7 and is deformed under pressure, so that a V-shaped groove is formed at the upper end of the contact surface, and it is easy to deposit hard objects such as quartz sand; and the plunger A7 makes rapid reciprocating motion on the sealing surface of the first ring A2, and the liquid with high hardness quartz sand is continuously subjected to high pressure washing of the first ring A2. Since the first ring A2 is a pure rubber product and does not have lubricating properties, the plunger sealing surface 5 in the first ring A2 is arc-shaped, and in this case, the hard objects are quickly brought into the plunger sealing surface 5 by the moving plunger A7; at the same time, the mutual friction between the plunger A7 and the first ring A2 generates heat, and the ambient temperature of the first ring A2 rises rapidly; under high pressure, high temperature and dynamic corrosive liquid, the performance of the first ring A2 will be accelerated, and it will be quickly torn and eroded, causing water leakage. The main reasons are as follows: first, the shape structure of the first ring A2 is unreasonable; second, the mutual friction between the first ring A2 and the plunger A7 generates heat quickly.

[0044] It should be noted that, as shown in Figure 4 The utility model discloses a kind of reciprocating motion self-lubricating first rings B2, which can effectively prolong the service life of self-lubricating first ring B2, reduce packing replacement frequency, so as to achieve the purpose of improving oil production efficiency.

[0045] In the above detailed description, various features are combined in a single embodiment to simplify the disclosure. This disclosure method should not be interpreted as reflecting the intention that the claimed subject matter requires more features clearly stated in each claim. On the contrary, as reflected in the appended claims, the utility model is in a state less than all the features of the disclosed single embodiment. Therefore, the appended claims are hereby clearly incorporated into the detailed description, wherein each claim is independently as a separate preferred embodiment of the utility model.

[0046] The foregoing description of the exemplary embodiments includes the best mode known to the inventors of practicing the disclosed application. Of course, variations on described embodiments can become apparent to those of ordinary skill in the art once the nature of the application is understood. Accordingly, it is intended that the disclosure be subject to reasonable modification by any of these varied means. It is intended that the true scope of the application be defined by the appended claims and their equivalents.

[0047] The above description includes one or more examples of the embodiments. Of course, describing the components and methods of the above-described embodiments is not possible to describe all possible combinations of components or methods for describing the above-described embodiments, but those of ordinary skill in the art should recognize that various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations falling within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the scope of the term is similar to the term "including", as explained in the context of "including" used as a transitional word in the claims. In addition, the use of any one term "or" in the specification is intended to mean "non-exclusive or" as explained in the context of "or" used as a transitional word in the claims.

[0048] The above specific embodiments, the purpose, technical solutions and advantages of the present application are further described in detail, it should be understood that the above description is only a specific embodiment of the present application, and is not intended to limit the protection scope of the present application, any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A reciprocating self-lubricating first ring, characterized by: The utility model relates to a kind of piston sealing surface (6) of sand scraping wall (5) of liquid storage tank (4) of bottom (1), outer wall (2), top end (3), wherein: The front end of the bottom (1) is provided with a bottom matching structure (1.1) that matches the contact surface of the pressure ring (A3);The two sides of the bottom (1) are respectively provided with the outer wall (2) and the piston sealing surface (6);The side of the outer wall (2) away from the bottom (1) is provided with the top end (3);The bottom of the top end (3) is provided with the liquid storage tank (4) for separating liquid and hard objects;The bottom of the liquid storage tank (4) and the piston sealing surface (6) are provided with the sand scraping wall (5) for scraping the liquid containing hard objects into the liquid storage tank (4).

2. The reciprocating self-lubricating primary ring of claim 1, wherein: The bottom matching structure (1.1) includes a semicircular arc protruding structure (1.1.1) and a slope surface (1.1.2);The semicircular arc protruding structure (1.1.1) is provided at the top end of the bottom matching structure (1.1) for matching positioning with the contact surface of the pressure ring (A3);Two slope surfaces (1.1.2) are respectively provided on both sides of the semicircular arc protruding structure (1.1.1). The included angle of the two slope surfaces (1.1.2) is 120 degrees, and the height is 3mm;The height of the semicircular arc protruding structure (1.1.1) is 1.8mm.

3. The reciprocating self-lubricating primary ring of claim 2, wherein: The liquid storage tank (4) includes a hard object separation tank (4.1), a liquid flow channel (4.2) and a liquid flow buffer zone (4.3), wherein: the hard object separation tank (4.1) is an inwardly recessed structure and is used for separating liquid and hard objects;The liquid flow channel (4.2) is provided between the hard object separation tank (4.1) and the sand scraping wall (5);The liquid flow buffer zone (4.3) is provided between the hard object separation tank (4.1) and the top end (3).

4. The reciprocating self-lubricating primary ring of claim 1, wherein: The height of the hard object separation tank (4.1) is 2.5mm;The height of the liquid flow channel (4.2) is 2mm;The height of the liquid flow buffer zone (4.3) is 2mm.

5. The reciprocating self-lubricating first ring of claim 4, wherein: The sand scraping wall (5) is a straight mouth structure.

6. The reciprocating self-lubricating primary ring of claim 1, wherein: The length of the sand scraping wall (5) is 4mm.

7. The reciprocating self-lubricating primary ring of claim 6, wherein: The piston sealing surface (6) is an outwardly protruding circular arc structure.

8. The reciprocating self-lubricating primary ring of claim 1, wherein: The radius of the circular arc of the piston sealing surface (6) is 9mm, and the height of the piston sealing surface (6) is 11mm.

9. The reciprocating self-lubricating first ring of claim 8, wherein: The surfaces of the bottom (1), the liquid storage tank (4), the sand scraping wall (5) and the piston sealing surface (6) are treated by fluorine coating process.

10. The reciprocating self-lubricating primary ring of claim 1, wherein: ​

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