Petroleum-proof and dust-proof structure of oil cylinder of oil pumping unit

Abstract

The petroleum and dust prevention structure comprises an end cover matched with a piston rod, an elastic piece, a first rod sealing ring and a compression nut are sequentially arranged in one end of the end cover, and the compression nut is in threaded connection with an opening of the end cover. The compression nut compresses the first rod sealing ring among the elastic piece, the end cover and the piston rod, and the inner ring of the compression nut and the inner ring of the first rod sealing ring make contact with the piston rod. By means of the mode, the petroleum and dust prevention structure of the oil pumping unit oil cylinder can improve durability of sealing pieces, prolong service life of the sealing pieces, reduce cost and be convenient and fast to maintain on the premise of reducing use of the sealing pieces.

Description

Technical Field

[0001] The utility model relates to the field of oil cylinders, in particular to a petroleum and dust proof structure of an oil cylinder of an oil pump. Background Art

[0002] For oil cylinders used in petroleum media, the working conditions need to be described in detail first: 1. The composition of oil is complex, including soil, stones, sulfides, crude oil and other substances. The front end of the oil cylinder needs to face different working conditions to prevent dust and oil; 2. After a long period of fermentation and compression, underground crude oil will be under pressure, and the pressure of crude oil varies in different regions and altitudes. Ordinary dust-proof end seals do not need to deal with pressure problems; 3. Normal use of oil pumps generally requires 24 hours of non-stop work. Except for maintenance every six months or so and the solidification of underground crude oil, the oil cylinder needs to be removed from the wellhead, otherwise it will continue to operate. This places great demands on the service life of the seals, and it must also be convenient for oil owners to maintain them. Although the previous oil cylinder design has a two-way sealing structure on the rod side and a modular segmented design (such as Figure 4 ) than the cylinder structure (such as Figure 5 ), but we believe that this design still cannot meet the long life requirements of customers, and this design relies on the stacking of seals to increase the service life of seals, which greatly increases the cost and places great demands on the assembly of cylinder manufacturers.

[0003] Conventional cylinder seals are not suitable for use in the oil industry because oil contains a large amount of stones, sulfides, etc. These fine particles can easily enter the cylinder and scratch the cylinder seals, resulting in frequent cylinder failures. Figure 4 The sealing structure of the guide sleeve side of the conventional hydraulic cylinder is shown as dust ring + rod seal ring + buffer ring + guide ring. According to our test, the conventional cylinder can only run for about one month under the condition of 2~4 back and forth movements per minute of the normal pumping unit, each movement stroke is 2000mm, and the cylinder will leak and fail under the condition of 24 hours of non-stop operation. Because the seal and structure have a large lateral force under this working condition, the cylinder will soon fail due to eccentric wear. Utility Model Content

[0004] The main technical problem solved by the utility model is to provide a petroleum and dust proof structure for an oil cylinder of an oil pump, which can improve the durability of the seals, extend the service life of the seals, reduce costs and facilitate maintenance while reducing the use of seals.

[0005] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a petroleum and dust proof structure of an oil cylinder of an oil pump, including an end cover matched with a piston rod, an elastic member, a first rod sealing ring and a clamping nut are sequentially arranged in one end of the end cover, the clamping nut is threadedly connected to the opening of the end cover, the clamping nut presses the first rod sealing ring between the elastic member, the end cover and the piston rod, and the inner ring of the clamping nut and the inner ring of the first rod sealing ring are in contact with the piston rod.

[0006] In a preferred embodiment of the utility model, the end cover has a stepped hole, the elastic member and the first rod sealing ring are located in the stepped hole, the front end of the clamping nut enters the stepped hole, and the rear end is threadedly connected to the opening of the end cover.

[0007] In a preferred embodiment of the present invention, a gap is provided between the elastic member and the piston rod.

[0008] In a preferred embodiment of the present invention, the elastic member is a leaf spring.

[0009] In a preferred embodiment of the utility model, a fender is provided inside the other end of the end cover, the side of the fender has a sharp corner, and an O-ring is provided between the upper end of the fender and the end cover.

[0010] In a preferred embodiment of the utility model, the piston rod is also connected with a guide cover, a second rod sealing ring is arranged in one end of the guide cover, and the second rod sealing ring is in contact with the piston rod.

[0011] In a preferred embodiment of the present invention, a dustproof ring is provided inside the other end of the guide cover.

[0012] In a preferred embodiment of the present invention, the first rod sealing ring and the second rod sealing ring are V-shaped combined sealing rings.

[0013] In a preferred embodiment of the present invention, an operating hole is provided on the outer end surface of the clamping nut.

[0014] In a preferred embodiment of the utility model, a flange is connected to the outer side of the end cover, an observation port is provided on the flange, and an observation cover for opening or closing the observation port is threadedly connected to the outer side of the flange.

[0015] The beneficial effects of the utility model are as follows: the oil and dust proof structure of the oil cylinder of the oil pumping unit of the utility model comprises a sealing structure composed of an elastic member, a V-shaped combined sealing ring and a gland nut; after the V-shaped combined sealing ring is worn, the compression nut can be rotated to cooperate with the elastic member to compress the V-shaped combined sealing ring to ensure the sealing effect.

[0016] The oil and dust proof structure of the oil cylinder of the utility model can effectively scrape off the sundries attached to the piston rod through the fender with sharp corners to protect the piston rod, and can cooperate with the O-ring to prevent the crude oil from entering the oil cylinder through the top, and can also prevent particles from being stuck in the upper position.

[0017] The oil-proof and dust-proof structure of the oil cylinder of the oil pumping unit of the utility model further improves the oil-proof effect by using the universal plug ring and the V-shaped combined sealing ring as the last layer of sealing.

[0018] The oil and dust proof structure of the oil cylinder of the utility model pumping unit cooperates with the observation port and the observation cover on the flange, so as to facilitate the adjustment of the compression nut and ensure the heat dissipation effect of the oil cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0020] Figure 1 It is a structural schematic diagram of the oil and dust proof structure of the oil cylinder of the utility model;

[0021] Figure 2 yes Figure 1 Schematic diagram of the local structure;

[0022] Figure 3 yes Figure 1 Schematic diagram of the local structure;

[0023] Figure 4 This is a schematic diagram of the structure of a conventional hydraulic cylinder guide sleeve;

[0024] Figure 5 This is a schematic diagram of a conventional oil cylinder seal structure;

[0025] The markings of the components in the accompanying drawings are as follows: 1. cylinder body, 2. piston rod, 3. guide cover, 4. flange, 5. end cover, 6. fender, 7. O-ring, 8. elastic member, 9. sealing ring for the first rod, 10. clamping nut, 11. sealing ring for the second rod, 12. dust ring, 13. operating hole, 14. observation port, 15. observation cover. DETAILED DESCRIPTION

[0026] The technical scheme in the embodiment of the utility model will be described clearly and completely below. The structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification, so that people familiar with this technology can understand and read, and are not used to limit the limiting conditions that can be implemented in the utility model, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that can be produced by the utility model and the purpose that can be achieved, should still fall within the scope of the technical content disclosed in the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of narration, and are not used to limit the scope that can be implemented. The change or adjustment of its relative relationship should also be regarded as the scope that can be implemented in the utility model without substantially changing the technical content.

[0027] See also Figures 1 to 3 , an oil and dust proof structure of a pumping unit oil cylinder, comprising a cylinder body 1, a piston rod 2 and a piston are arranged in the cylinder body 1, and the rear end of the cylinder body 1 is connected to a guide cover 3 and a flange 4 in sequence. An end cover 5 is installed inside the flange 4, and the piston rod 2 cooperates with the end cover 5 and the guide cover 3. The rest of the oil cylinder is a conventional structure in the art, and will not be described here.

[0028] A fender 6 is provided inside the left end of the end cover 5, the side of the fender 6 has a sharp corner, and an O-ring 7 is provided between the upper end of the fender 6 and the end cover 5. The fender 6 is the first part of the entire oil cylinder to contact the crude oil and is the first to be impacted, so conventional seals cannot be used here. A copper fender 6 is used. Since copper has lubricity, it will not damage the piston rod 2, and the pressure on the crude oil side is not very high, so copper parts are very good at resisting the pressure of oil impact. At the same time, the fender 6 has a sharp corner. There are many viscous sulfides in the crude oil that will adhere to the piston rod 2 and corrode the coating. In this way, the sulfides can be removed through this sharp corner, and the coating of the piston rod 2 is well protected. Since the assembly of the fender 6 is not tightly matched, in order to avoid the gap when the fender 6 floats up and down, an O-ring 7 is set above the fender 6 to prevent the crude oil from passing through the top to the inside of the oil cylinder, and also prevent particles from getting stuck in the upper position of the fender 6.

[0029] An elastic member 8, a first rod sealing ring 9 and a clamping nut 10 are sequentially arranged in one end of the end cover 5. The clamping nut 10 is threadedly connected to the opening of the end cover 5. The clamping nut 10 compresses the first rod sealing ring 9 between the elastic member 8, the end cover 5 and the piston rod 2. The inner ring of the clamping nut 10 and the inner ring of the first rod sealing ring 9 are in contact with the piston rod 2. After the V-type combined sealing ring is worn, the V-type combined sealing ring is composed of multiple multi-V-shaped seals. It only needs to continue to tighten the clamping nut 10 inwardly, so that the lip of the V-shaped seal can be further opened through the extrusion of the spring sheet and the clamping nut 10, and it can continue to be used.

[0030] The end cover 5 has a stepped hole, the elastic member 8 and the first rod sealing ring 9 are located in the stepped hole, the front end of the clamping nut 10 enters the stepped hole, and the rear end is threadedly connected to the opening of the end cover 5. A gap is set between the elastic member 8 and the piston rod 2. During installation, the spring is first installed, and then the V-shaped combined sealing ring is placed in the end cover 5, and finally the clamping nut 10 is threadedly connected to the end cover 5, so that the sealing structure is assembled. The service life of this sealing structure is prolonged, and on the basis of reducing the number of sealing parts, a sealing effect equal to or even better than that of a combination of multiple sealing parts is obtained.

[0031] The preferred elastic member 8 is a leaf spring, and of course other common elastic members 8 can also be used instead, which can also achieve the compression of the first rod sealing ring 9. The first rod sealing ring 9 is a V-shaped combined sealing ring, which can scrape crude oil and has the function of resisting pressure. In order to avoid wear of the piston rod 2, the clamping nut 10 also uses a notification nut. An operating hole 13 is provided on the outer end face of the clamping nut 10, so that when the oil workers are overhauling, they can use specific tools to tighten the clamping nut 10 through the observation port 14, which reduces the technical difficulty requirements of the workers' operation.

[0032] The piston rod 2 is also connected with the guide cover 3. A second rod seal ring 11 is provided in one end of the guide cover 3. The second rod seal ring 11 contacts the piston rod 2. A dust ring 12 is provided in the other end of the guide cover 3. The second rod seal ring 11 is a V-shaped combined seal ring. The structure of the dust ring 12 continues the existing structure. A part of the crude oil and dust and debris generated at the observation port 14 are scraped off by the dust ring 12. The second rod seal ring 11 is the last anti-crude oil seal. Through the advantages of the V-shaped combined seal ring, the anti-oil effect is further improved.

[0033] An observation port 14 is provided on the flange 4, and an observation cover 15 for opening or closing the observation port 14 is threadedly connected to the outer side of the flange 4. The observation port 14 is connected by a T-type thread. Under normal circumstances, the observation cover 15 is closed and will only be opened during maintenance. The T-type thread is self-locking, and the performance requirements of the thread only need to meet the self-locking requirements, so that the worker can push up the observation cover 15 during operation. At the same time, the design area of ​​the observation port 14 is increased, which is convenient for the workers to inspect and repair, and can also meet the heat dissipation between the seals. At the same time, because the distance here is long and the crude oil film is heavy, the oil film will flow downward along the piston rod 2, and the adhesion ability of the crude oil film on the piston rod 2 is reduced through the action of gravity.

[0034] Different from the prior art, the oil and dust proof structure of the oil cylinder of the utility model can improve the durability of the seals, extend the service life of the seals, reduce costs and facilitate maintenance while reducing the use of seals.

[0035] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A petroleum and dust proof structure for a pumping unit cylinder, comprising an end cover (5) matched with a piston rod (2), characterized in that: An elastic member (8), a first rod sealing ring (9) and a clamping nut (10) are sequentially arranged inside one end of the end cover (5); the clamping nut (10) is threadedly connected to the opening of the end cover (5); the clamping nut (10) presses the first rod sealing ring (9) between the elastic member (8), the end cover (5) and the piston rod (2); the inner ring of the clamping nut (10) and the inner ring of the first rod sealing ring (9) are in contact with the piston rod (2).

2. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 1 is characterized in that: The end cover (5) has a stepped hole, the elastic member (8) and the first rod sealing ring (9) are located in the stepped hole, the front end of the compression nut (10) enters the stepped hole, and the rear end is threadedly connected to the opening of the end cover (5).

3. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 2 is characterized in that: A gap is provided between the elastic member (8) and the piston rod (2).

4. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 3 is characterized in that: The elastic member (8) is a leaf spring.

5. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 1, characterized in that: A fender (6) is provided inside the other end of the end cover (5), the side of the fender (6) having a sharp corner, and an O-ring (7) is provided between the upper end of the fender (6) and the end cover (5).

6. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 1, characterized in that: The piston rod (2) is also connected in cooperation with the guide cover (3); a second rod sealing ring (11) is provided in one end of the guide cover (3); the second rod sealing ring (11) is in contact with the piston rod (2).

7. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 6, characterized in that: A dustproof ring (12) is provided inside the other end of the guide cover (3).

8. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 6, characterized in that: The first rod sealing ring (9) and the second rod sealing ring (11) are V-shaped combined sealing rings.

9. The oil and dust proof structure of the oil cylinder of the oil pump according to any one of claims 1 to 8, characterized in that: An operating hole (13) is provided on the outer end surface of the clamping nut (10).

10. The oil and dust proof structure of the oil cylinder of the oil pump according to claim 9, characterized in that: The outer side of the end cover (5) is connected to a flange (4), an observation port (14) is provided on the flange (4), and an observation cover (15) for opening or closing the observation port (14) is threadedly connected to the outer side of the flange (4).

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