Hydraulic pumping unit without external leakage cylinder

Abstract

The oil cylinder without external leakage of the hydraulic pumping unit relates to the field of hydraulic pumping units. The oil cylinder is provided with two cylinder barrels, namely an outer cylinder barrel and an inner cylinder barrel. One end of the outer cylinder barrel is connected to the cylinder bottom by threads, and the other end is connected to the outside of the cylinder head by threads. One end of the inner cylinder barrel is connected to the inside of the cylinder head by threads, and the other end of the inner cylinder barrel is connected with an upper sealing gland. The inner cylinder barrel and the piston rod are sealed by an upper sealing group. A piston rod is arranged inside the inner cylinder barrel. The cylinder head of the oil cylinder is connected to the flange by bolts. The piston rod and the cylinder head are sealed by a lower sealing group, and a lower sealing gland is installed outside the lower sealing group. A moving component is installed inside the oil cylinder. The cylinder bottom is connected to a cover by bolts. A displacement sensor is installed inside the cover, and the other end of the displacement sensor is connected to an external electronic control system. An oil inlet / outlet is arranged at the end of the outer cylinder barrel close to the cylinder head, and an oil port is arranged on the outer cylinder barrel. The hydraulic oil seal of the piston rod is cancelled in terms of structure, fundamentally solving the external leakage at the piston rod of the oil cylinder.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic pumping units, and in particular to a hydraulic pumping unit cylinder without external leakage. Background Art

[0002] Compared with traditional beam pumping units, hydraulic pumping units have obvious technical advantages in terms of safety, energy conservation, emission reduction, digitalization, and intelligentization. However, problems such as oil leakage from the cylinder and hydraulic oil pollution caused by external leakage of the hydraulic cylinder have not been fundamentally solved, thus greatly restricting the popularization and application of hydraulic pumping units.

[0003] The present invention proposes a hydraulic cylinder without external leakage. By eliminating the rod end seal of the cylinder in terms of structure, it can achieve long-term use of the cylinder under the condition of lateral force without external leakage, fundamentally solving the problem of external leakage of the hydraulic cylinder of the hydraulic pumping unit. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydraulic pumping unit cylinder without external leakage to solve problems such as oil leakage from the cylinder and hydraulic oil pollution caused by external leakage of the hydraulic cylinder.

[0005] The technical solution of the present invention is a hydraulic pumping unit cylinder without external leakage, including a piston rod 1, a flange 2, a cylinder head 3, an oil inlet and outlet 4, an outer cylinder barrel 5, an inner cylinder barrel 6, an oil drain hole 7, an oil port 8, an upper seal 9, an upper seal gland 10, a support cylinder 11, an exhaust hole 12, a guide head 13, a cylinder bottom 14, a displacement sensor 15, a cover 16, an air filter and silencer 17, a wear-resistant seal sleeve for the guide head 18, a sealing ring 19, a piston 20, a stop tube 21, a lower seal group 22, and a lower seal gland 23. The cylinder of the hydraulic cylinder is provided with two cylinder barrels, namely an outer cylinder barrel 5 and an inner cylinder barrel 6. The length of the inner cylinder barrel is less than that of the outer cylinder barrel. One end of the outer cylinder barrel 5 is connected to the cylinder bottom 14 by thread, and the other end is connected to the outside of the cylinder head 3 by thread. One end of the inner cylinder barrel 6 is connected to the inside of the cylinder head 3 by thread, and the other end of the inner cylinder barrel 6 is connected to the upper seal gland 10. The inner cylinder barrel 6 and the piston rod are sealed by an upper seal group 9. The piston rod 1 is arranged inside the inner cylinder barrel 6. The cylinder head 3 of the hydraulic cylinder is connected to the flange 2 by bolts. The piston rod and the cylinder head 3 are sealed by a lower seal group 22. A lower seal gland 23 is installed outside the lower seal group 22. A moving component 30 is installed inside the hydraulic cylinder. The cylinder bottom 14 is connected to the cover 16 by bolts. The displacement sensor 15 is installed inside the cover 16. The displacement sensor 15 is connected to the piston rod by a circuit. The other end of the displacement sensor is connected to an external electronic control system. An oil inlet and outlet 4 is arranged at the end of the outer cylinder barrel 5 close to the cylinder head 3. An oil port 8 is arranged on the outer cylinder barrel 5.

[0006] The movable component 30 includes an oil cylinder piston 20, a support cylinder 11, a guide head 13, a piston rod 1, and a stop pipe 21. The piston 20 is arranged between the outer cylinder 5 and the inner cylinder 6, near the side of the upper sealing gland 10. The piston 20 is sealed with the inner and outer cylinders through a sealing component. One side of the piston 20 is threadedly connected to the support cylinder 11, and a stop pipe 21 is installed on the other side of the piston 20. The stop pipe 21 is sleeved on the inner cylinder 6 and contacts the piston 20. One end of the support cylinder 11 is threadedly connected to the piston 20, and the other end of the support cylinder 11 is threadedly connected to the guide head 13. The guide head 13 is threadedly connected to the top end of the piston rod 1. The inner cylinder 6 and the support cylinder 11 are sealed by a sealing ring 19. The support cylinder 11 is provided with an oil drain hole 7, which is close to the piston 20 and close to the oil drain port 8. The guide head 13 is provided with an exhaust hole 12, and a wear-resistant sealing sleeve 18 for the guide head is installed outside the guide head 13.

[0007] The space between the piston rod and the cylinder head is sealed by a lower sealing component 22, which includes a lower packing 221, an oil collecting groove 222, a sealing ring I 223, a guide sleeve 224, and a fluororubber sealing ring 225. The lower packing is installed in the groove of the cylinder head 3. The lower packing 221 directly contacts the petroleum and bears the lateral force of the piston rod. Therefore, it should be mainly made of a polytetrafluoroethylene and aramid composite material with high temperature resistance, high pressure resistance, and good lubrication, mainly providing good self-lubrication, excellent wear resistance, and sealing performance. The sealing ring 223 should be a polyurethane or fluororubber sealing ring resistant to petroleum corrosion; the guide sleeve 224 should be made of PEEK material with wear resistance, corrosion resistance, high temperature resistance, and self-lubrication. The hydraulic oil sealing between the piston and the cylinder barrel: Ensure that the internal leakage of the oil cylinder meets the requirements of relevant standards.

[0008] A filter silencer 17 is installed inside the cover 16, and the silencer is installed on the opposite side of the displacement sensor.

[0009] The piston 20 moves between the outer cylinder 5 and the inner cylinder 6.

[0010] A wear-resistant sealing sleeve 18 for the guide head is sleeved outside the guide head 13. The guide head 13 is provided with an exhaust hole 12, and the exhaust hole 12 is coaxially communicated with the hole of the wear-resistant sealing sleeve 18 for the guide head.

[0011] The upper sealing group 9 includes an upper packing (91), a sealing ring III (95), a rubber ring (93), and a guide (94). The upper packing (91) is installed between the inner cylinder and the piston rod. The sealing ring (19) is installed in the groove of the upper gland (10) to seal the upper sealing gland (10) and the piston rod (1). The rubber ring (93) is installed in the groove at the top end of the inner cylinder to seal the inner cylinder (6) and the support cylinder (11). The sealing ring III (95) is installed in the grooves on both sides of the piston (20) to seal the piston and the inner and outer cylinders. The guide (94) is installed in the middle groove of the piston to seal the piston and the inner and outer cylinders.

[0012] The material of the upper packing gland (91) is polytetrafluoroethylene. The sealing ring (19) is a polyurethane sealing ring. The rubber ring (93) is a nitrile rubber ring. The guide (94) is a phenolic fabric guide. The sealing ring III (95) is a polyurethane sealing ring.

[0013] The working principle of the present invention: The hydraulic oil with a certain pressure and flow rate provided by the oil pump enters the oil cylinder from the oil inlet and outlet (4), pushing the moving components composed of the oil cylinder piston (20), support cylinder (11), guide head (13), piston rod (1), and stop pipe (21) to move upward, driving the piston rod 1 to rise. The rising stroke collects signals through the displacement sensor (15). When the displacement reaches the set value, the oil pump stops supplying oil. Under the action of the gravity load, the hydraulic oil is discharged from the oil cylinder through the oil inlet and outlet (4).

[0014] The beneficial technical effects of the present invention:

[0015] The oil cylinder consists of two inner and outer cylinder barrels. The piston moves between the inner and outer cylinder barrels, and the piston rod moves inside the inner cylinder barrel. The hydraulic oil seal of the piston rod is cancelled in the structure, fundamentally solving the external leakage at the piston rod of the oil cylinder.

[0016] The seal leakage of the piston is internal leakage, which can be discharged back to the fuel tank through the oil drain hole and oil outlet for reuse, without causing the external leakage of hydraulic oil, and solving problems such as environmental pollution.

[0017] There is a sealing ring between the inner cylinder barrel and the support cylinder for sealing. A small amount of internally leaked hydraulic oil is directly discharged back to the fuel tank without directly contacting the piston rod, eliminating the risk of the hydraulic oil being contaminated by the piston rod.

[0018] The piston rod is sealed at the upper and lower ends of the inner cylinder barrel, which can ensure that petroleum and other pollutants enter the oil cylinder. After long-term use, a small amount of petroleum entering due to seal wear is sealed in the support cylinder and cannot contact the internally leaked hydraulic oil of the piston, without polluting the hydraulic oil.

[0019] Since there is no rod end seal in the structure of the oil cylinder, the damage to the rod end seal caused by the lateral force on the piston rod is fundamentally solved.

[0020] Multiple petroleum seals are arranged by using the fixed space between the inner diameter of the inner cylinder barrel and the piston rod to ensure good petroleum sealing. Even if a certain amount of petroleum enters this fixed space, it will gradually solidify, hindering the further intrusion of subsequent petroleum. Description of the Drawings

[0021] Figure 1 is the structural schematic diagram of the present invention.

[0022] Figure 2 is the schematic diagram of the extended state in the present invention.

[0023] Figure 3 It is a schematic diagram of the local structure in the present invention.

[0024] Figure 4 It is a schematic diagram of the lower sealing structure in the present invention.

[0025] Figure 5 It is a schematic diagram of the upper sealing structure in the present invention. Embodiment

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Please refer to Figures 1-5 As shown, a technical solution provided by the present invention:

[0028] A hydraulic pumping unit cylinder without external leakage, comprising a piston rod 1, a flange 2, a cylinder head 3, an oil inlet and outlet 4, an outer cylinder barrel 5, an inner cylinder barrel 6, an oil drain hole 7, an oil port 8, an upper seal 9, an upper seal gland 10, a support cylinder 11, an exhaust hole 12, a guide head 13, a cylinder bottom 14, a displacement sensor 15, a cover 16, an air filter and silencer 17, a wear-resistant seal sleeve 18 for the guide head, a sealing ring 19, a piston 20, a stop pipe 21, a lower seal assembly 22, and a lower seal gland 23. The cylinder has two cylinder barrels, namely the outer cylinder barrel 5 and the inner cylinder barrel 6. The length of the inner cylinder barrel is less than that of the outer cylinder barrel, slightly less than half of the outer cylinder barrel. One end of the outer cylinder barrel 5 is connected to the cylinder bottom 14 by a thread, and the other end is connected to the outside of the cylinder head 3 by a thread. One end of the inner cylinder barrel 6 is connected to the inside of the cylinder head 3 by a thread, and the other end of the inner cylinder barrel 6 is connected to the upper seal gland 10. The inner cylinder barrel 6 and the piston rod are sealed by the upper seal assembly 9. The outer part of the inner cylinder barrel 6 is sleeved with the piston 20. The piston 20 is arranged between the outer cylinder barrel 5 and the inner cylinder barrel 6 and is sealed with the inner and outer cylinder barrels through a sealing component. One side of the piston 20 is connected to the support cylinder 11 by a thread, and a stop pipe 21 is installed on the other side of the piston 20. The stop pipe 21 is sleeved on the inner cylinder barrel 6 and contacts the piston 20. One end of the support cylinder 11 is connected to the piston 20 by a thread, and the other end of the support cylinder 11 is connected to the guide head 13 by a thread. The guide head 13 is connected to the top end of the piston rod 1 by a thread. The cylinder head 3 is connected to the flange 2 by bolts. The flange 2 and the piston rod 1 are sealed by the lower seal assembly 22, and the lower seal gland 23 is installed outside the lower seal assembly 22. The cylinder bottom 14 is connected to the cover 16 by bolts. The displacement sensor 15 is installed in the cover 16. The displacement sensor 15 receives the position signal of the piston rod, and the other end of the displacement sensor is connected to an external electronic control system. The inner cylinder barrel 6 and the support cylinder 11 are sealed by the sealing ring 19. An oil inlet and outlet 4 is arranged at the end of the outer cylinder barrel 5 close to the cylinder head 3. An oil port 8 is arranged on the outer cylinder barrel 5. An oil drain hole 7 is arranged at the lower end of the support cylinder 11. The oil drain hole 7 is close to the piston 20. The guide head 13 is provided with an exhaust hole 12, and a wear-resistant seal sleeve 18 for the guide head is installed outside the guide head 13.

[0029] An air filter and silencer 17 is installed in the cover 16, and the silencer is installed on the opposite side of the displacement sensor.

[0030] The piston 20 moves between the outer cylinder barrel 5 and the inner cylinder barrel 6.

[0031] There is a gap between the inner cylinder barrel 6 and the support cylinder 11, and the size of the gap can be adjusted according to the dimensions.

[0032] The piston 20 does not fit tightly with the top end of the inner cylinder barrel 6, and there is a gap. The oil of the piston can flow through the gap to the oil drain hole 7 arranged on the support cylinder 11 and then flow to the system circuit through the oil drain hole 7 and the oil port 8.

[0033] A wear-resistant seal sleeve 18 for the guide head is sleeved outside the guide head 13, and the guide head 13 is provided with an exhaust hole 12.

[0034] The oil drain hole 7 is close to the piston 20, the oil drain hole 7 is higher than the piston 20 and lower than the top end of the inner cylinder barrel 6. It is necessary to ensure that the oil drain hole 7 is not blocked when the piston rod 1 is fully retracted.

[0035] Operation process of the present invention: The hydraulic oil cylinder flange 2 of the hydraulic pumping unit is directly seated on the wellhead to prevent oil leakage. It is fastened by bolts. The oil inlet and outlet 4 is connected to the power oil port of the pumping unit system, the oil port 8 is connected to the circuit of the pumping unit system, and the displacement sensor 15 is connected to the electric control system of the pumping unit to collect displacement signals. The oil pump provides hydraulic oil with a certain pressure and flow rate and enters the oil cylinder from the oil inlet and outlet 4. After the hydraulic oil enters, it pushes the stop tube 21 to move. The stop tube 21 moves upward and pushes the piston rod 1 to move. The piston rod is connected to the support tube 11, and the support tube 11 moves upward. The support cylinder 11 is connected to the guide head, and the guide head moves upward, driving the sucker rod to move upward. The ascending stroke collects signals through the displacement sensor 15. When the displacement reaches the set value, the oil pump stops supplying oil. Under the action of the gravity load, the piston rod 1 with the oil cylinder moves downward. The piston rod 1 moves downward, and the guide head on the piston rod 1 follows and moves downward. The guide head drives the support tube 11 to move. The support rod is connected to the piston 20, the piston is connected to the stop tube 21, and the stop tube 21 moves downward accordingly. The hydraulic oil is discharged from the oil cylinder through the oil inlet and outlet 4. The downward stroke collects signals through the displacement sensor 15. When the displacement reaches the set value, the oil pump starts to supply oil. A new movement begins. The stroke of the piston rod is slightly less than half of the length of the oil cylinder barrel. When internal leakage occurs in the piston 20, the oil flows through the oil drain hole 7 into the oil port 8 and then flows back to the system circuit, without external leakage. The seal leakage of the piston is internal leakage, which can be discharged back to the fuel tank through the oil drain hole and the oil drain port for reuse, without causing external leakage of the hydraulic oil and solving problems such as environmental pollution. The present invention can generate 0.1L - 0.15L less external leakage per day than conventional hydraulic pumping units, converting the original external leakage into internal leakage, ensuring compliance with relevant national standards, and greatly reducing energy waste during the operation of the hydraulic pumping unit. The present invention is provided with an oil seal including an upper seal 9 and a lower seal group 22 to prevent oil from contacting the hydraulic oil. Especially under the guiding action of the lower seal group 22, the upper seal 9 has almost no lateral force. Then, the sucker rod is sealed by a packing seal to prevent the hydraulic oil from being contaminated by oil, extending the service life of hydraulic components by up to 80%.

Claims

1. A hydraulic pumping unit cylinder without external leakage, comprising a piston rod (1), a flange (2), a cylinder head (3), an oil inlet and outlet (4), an outer cylinder barrel (5), an inner cylinder barrel (6), an oil drain hole (7), an oil port (8), an upper sealing group (9), a cylinder bottom (14), a piston (20), and a moving component (30), characterized in that: The oil cylinder is provided with two cylinder barrels, namely an outer cylinder barrel (5) and an inner cylinder barrel (6). The length of the inner cylinder barrel (6) is less than that of the outer cylinder barrel (5). One end of the outer cylinder barrel (5) is connected to the cylinder bottom (14) by means of a thread, and the other end of the outer cylinder barrel (5) is connected to the outside of the cylinder head (3) by means of a thread. One end of the inner cylinder barrel (6) is connected to the inside of the cylinder head (3) by means of a thread, and the other end of the inner cylinder barrel (6) is connected to the upper sealing gland (10). The inner cylinder barrel (6) and the piston rod are sealed by an upper sealing group (9). A piston rod (1) is arranged inside the inner cylinder barrel (6). The cylinder head (3) of the oil cylinder is connected to the flange (2) by means of bolts. The piston rod and the cylinder head (3) are sealed by a lower sealing group (22). A lower sealing gland (23) is installed outside the lower sealing group (22). A moving component (30) is installed inside the oil cylinder. The moving component (30) is installed on the piston rod (1). The cylinder bottom (14) is connected to a cover (16) by means of bolts. A displacement sensor (15) is installed inside the cover (16). The displacement sensor (15) is connected to the piston rod (1), and the other end of the displacement sensor (15) is connected to an external electronic control system. An oil inlet / outlet (4) is arranged at the end of the outer cylinder barrel (5) close to the cylinder head (3). An oil port (8) is arranged on the outer cylinder barrel (5). The moving component (30) includes an oil cylinder piston (20), a support cylinder (11), a guide head (13), a piston rod (1), and a stop tube (21). Among them, the piston (20) is arranged between the outer cylinder barrel (5) and the inner cylinder barrel (6), and is close to the side of the upper sealing gland (10). The piston (20) is sealed with the inner and outer cylinder barrels through a sealing component. One side of the piston (20) is connected to the support cylinder (11) by means of a thread, and a stop tube (21) is installed on the other side of the piston (20). The stop tube (21) is sleeved on the inner cylinder barrel (6), and the stop tube (21) is in contact with the piston (20). One end of the support cylinder (11) is connected to the piston (20) by means of a thread, and the other end of the support cylinder (11) is connected to the guide head (13) by means of a thread. The guide head (13) is connected to the top end of the piston rod (1) by means of a thread. The inner cylinder barrel (6) and the support cylinder (11) are sealed by a sealing ring (19). The support cylinder (11) is provided with an oil drain hole (7). The oil drain hole (7) is close to the piston (20) and is close to the oil drain port (8). The guide head (13) is provided with an exhaust hole (12). A wear-resistant sealing sleeve (18) of the guide head is installed outside the guide head (13). The lower sealing group (22) includes a lower packing (221), an oil sump (222), a sealing ring I (223), a guide sleeve (224), and a fluororubber sealing ring (225). Among them, the lower sealing group (22) is installed in a groove of the cylinder head (3). The lower packing (221) is selected from polytetrafluoroethylene or aramid composite materials, and the sealing ring I (223) is selected from polyurethane or fluororubber sealing rings; the guide sleeve (224) is selected from PEEK materials.

2. A hydraulic pumping unit without external leakage cylinder according to claim 1, characterized in that: A filter silencer (17) is installed inside the cover (16), and the filter silencer (17) is installed on the side opposite to the displacement sensor.

3. The hydraulic oil pumping unit without external leakage cylinder according to claim 1, wherein: The guide head (13) is externally sleeved with a wear-resistant sealing sleeve (18) of the guide head. The guide head (13) is provided with an exhaust hole (12), and the exhaust hole (12) is coaxially communicated with the hole of the wear-resistant sealing sleeve (18) of the guide head.

4. A hydraulic pumping unit without external leakage cylinder according to claim 1, characterized in that: The upper sealing group (9) includes an upper packing (91), a sealing ring III (95), a rubber ring (93), and a guide (94). Among them, the upper packing (91) is installed between the inner cylinder barrel and the piston rod. The sealing ring (19) is installed in the groove of the upper sealing gland (10) to seal the upper sealing gland (10) and the piston rod (1). The rubber ring (93) is installed in the groove at the top of the inner cylinder barrel to seal the inner cylinder barrel (6) and the support cylinder (11). The sealing ring III (95) is installed in the grooves on both sides of the piston (20) to seal the piston and the inner and outer cylinder barrels. The guide (94) is installed in the middle groove of the piston to seal the piston and the inner and outer cylinder barrels.

5. A hydraulic pumping unit without external leakage cylinder according to claim 4, characterized in that: The material of the upper packing (91) is polytetrafluoroethylene. The sealing ring (19) is a polyurethane sealing ring. The rubber ring (93) is a nitrile rubber ring. The guide (94) is a phenolic cloth guide, and the sealing ring III (95) is a polyurethane sealing ring.

6. A hydraulic pumping unit without external leakage cylinder according to claim 1, characterized in that: Its working process Step 1: Directly seat the hydraulic pumping unit cylinder flange (2) on the wellhead and fasten it with bolts. Connect the oil inlet and outlet (4) to the power oil port of the pumping unit system, connect the oil port (8) to the return circuit of the pumping unit system, and connect the displacement sensor (15) to the pumping unit electric control system to collect displacement signals. Step 2: The hydraulic oil provided by the oil pump with a certain pressure and flow rate enters between the inner and outer cylinder barrels of the cylinder from the oil inlet and outlet (4). After the hydraulic oil enters, it pushes the stop pipe (21) to move. The stop pipe (21) moves upward, pushing the piston rod (1) to move. The piston rod is connected to the support cylinder (11), and the support cylinder (11) moves upward. The support cylinder (11) is connected to the guide head (13), and the guide head (13) moves upward, driving the sucker rod to move upward. The rising stroke collects signals through the displacement sensor (15). When the displacement reaches the set value, the oil pump stops supplying oil. Step 3: Under the action of the gravity load, the piston rod (1) contained in the cylinder moves downward, and the guide head (13) on the piston rod (1) moves downward accordingly. The guide head drives the support cylinder (11) to move. The support rod is connected to the piston (20), and the piston is connected to the stop pipe (21). The stop pipe (21) moves downward accordingly, and the hydraulic oil is discharged from the cylinder through the oil inlet and outlet (4). The downward stroke collects signals through the displacement sensor (15). When the displacement reaches the set value, the oil pump starts to supply oil and starts a new movement for the next time.

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