Deep-well high-speed vertical pump having dynamic pressure-balanced dynamic seal

Abstract

A deep-well high-speed vertical pump having dynamic pressure-balanced dynamic seal, relating to the technical field of deep-well pump design. Upper and lower end covers are respectively threadedly connected to two ends of a pump housing; liquid inlets are formed in the lower end cover; a stator winding is fixed to the upper portion of the inner wall of the pump housing; an opening end of an annular cylinder of an annular differential pressure balancer faces downward and is threadedly connected to the lower portion of the inner wall of the pump housing; an annular piston is slidably and sealedly inserted in the annular cylinder; balance holes are formed in a closed end of the annular cylinder; a reset spring is supported between the annular piston and the lower end cover; a hollow main shaft of a rotor assembly is rotatably mounted between the upper end cover and the lower end cover; a silicon steel sheet is fixed to the upper portion of the outer wall of the hollow main shaft; O-shaped dynamic seal rings are provided between the hollow main shaft and the annular cylinder and between the hollow main shaft and the upper end cover; and a spiral strip is arranged around a central shaft and is connected and fixed to the inner wall of the hollow main shaft by means of welding points. The hollow main shaft of the motor rotor assembly is used as a flow channel, and the spiral strip is welded to the inner wall of the hollow main shaft, such that the pump is not prone to wear. The annular differential pressure balancer is additionally provided to avoid leakage at a dynamic seal position in a high-pressure environment.

Description

Deep well high-speed inner lifting pump with dynamic pressure balance and dynamic seal TECHNICAL FIELD

[0001] The present application relates to the technical field of deep well pump design, and particularly relates to a deep well high-speed inner lifting pump with dynamic pressure balance and dynamic seal. BACKGROUND

[0002] With the continuous development of China's oil industry, most oil fields have entered the middle and late stages of exploitation, and the overdeep oil wells and reduced oil production of the middle and late oil fields are no longer suitable for high-energy and low-efficiency oil pumping methods. Most of the traditional oil extraction pumps use power frequency motors, and the power density is not high, so multiple pump bodies need to be connected in series to obtain high lift, and the friction between impurities in the stratum liquid and the pump body easily causes pump body wear, the service life is not long, and there is a high requirement for the presence of impurities in the liquid. In addition, because the working environment is in a deep well, the environmental pressure is high, which makes it difficult to seal dynamically, and the liquid in the working environment easily enters the pump body through the dynamic sealing place due to the high pressure difference between the inside and outside of the pump, which causes working failure.

[0003] The Chinese utility model patent with the publication number CN217813977U, the publication date of November 15, 2022, and the name of a hollow through shaft pump discloses a hollow through shaft pump, the motor shaft center of which penetrates, but the impeller is still circumscribed outside the motor shaft, which has certain requirements for the mechanical structure strength and the stability of the working environment, and under high-speed working conditions, the impeller is easy to rub and collide with impurities and sundries in the transported liquid, thereby damaging the impeller, and the design of the circumscribed impeller is not conducive to the series connection of multiple water pumps. SUMMARY

[0004] To solve the problems in the background art, the present application provides a deep well high-speed inner lifting pump with dynamic pressure balance and dynamic seal, which uses the hollow main shaft of the motor rotor assembly as a flow channel, and has a spiral strip welded inside for lifting the liquid, which is not easy to block and helps to reduce wear, and the added annular differential pressure balancer can achieve dynamic balance of the pressure inside and outside the pump, avoid leakage at the dynamic sealing place under high pressure, and facilitate the series connection of multiple pumps.

[0005] To achieve the above object, the application adopts the following technical scheme: a deep-well high-speed inner-lifting pump with dynamic pressure balance and dynamic seal, comprising a pump shell, an upper end cover, a lower end cover, a stator and winding, a rotor assembly, an annular differential pressure balancer and a reset spring, the pump shell is a cylindrical member, the upper end cover and the lower end cover are both annular members and are respectively threadedly connected and fixed with the upper and lower ends of the pump shell, the lower end cover is processed to have a liquid inlet hole, the stator and winding are fixed on the upper part of the inner wall of the pump shell, the annular differential pressure balancer comprises an annular cylinder and an annular plug, the annular cylinder has a downward opening end and is threadedly connected and fixed with the lower part of the inner wall of the pump shell, the annular plug is slidingly and sealingly inserted into the opening end of the annular cylinder and forms a cylinder chamber inside, the closed end of the annular cylinder is processed to have a balance hole, the reset spring is supported between the annular plug and the lower end cover, the rotor assembly comprises a hollow main shaft, a spiral strip, a central shaft and a silicon steel sheet, the hollow main shaft is coaxially and rotatably installed between the central holes of the upper end cover and the lower end cover, the silicon steel sheet is fixed on the upper part of the outer wall of the hollow main shaft and is gap-fitted with the area where the stator and winding are located, a first O-shaped dynamic seal ring is arranged between the hollow main shaft and the annular cylinder, a second O-shaped dynamic seal ring is arranged between the hollow main shaft and the upper end cover, the central shaft is coaxially and lengthwise arranged in the hollow main shaft, the spiral strip is processed and arranged around the central shaft, and the edge of the spiral strip is connected and fixed with the corresponding position of the inner wall of the hollow main shaft through a welding point.

[0006] Further, the lower end face of the lower end cover is provided as a tapered face with the thickness gradually decreasing from the edge to the central hole.

[0007] Further, the silicon steel sheet of the rotor assembly has an upper oil cavity and a lower oil cavity formed between the upper and lower ends of the silicon steel sheet and the cavities between the upper end cover and the annular cylinder respectively, and the upper oil cavity and the lower oil cavity are both filled with cooling lubricating oil.

[0008] Further, the annular plug comprises a plug body and a plug seat, the plug body is slidingly and sealingly inserted into the opening end of the annular cylinder, and the plug seat is formed by the thickening of the extension of the bottom end of the plug body inward and outward.

[0009] Further, the upper end cover is processed to have a threading hole for leading out and sealing the connecting line of the stator and winding and the power supply.

[0010] Further, the annular cylinder has an outer sliding seal ring and an inner sliding seal ring arranged on both sides of the inner wall adjacent to the open end respectively, the outer sliding seal ring is in close contact with the outer ring surface of the annular plug, and the inner sliding seal ring is in close contact with the inner ring surface of the annular plug.

[0011] Further, a first O-shaped static seal ring is arranged between the annular cylinder and the pump shell.

[0012] Further, a second O-shaped static seal ring is arranged between the upper end cover and the pump shell.

[0013] Further, the balance holes are multiple and arranged equidistantly along the circumference at the closed end of the annular cylinder, and the diameters of the multiple balance holes are consistent.

[0014] Further, the liquid inlet holes are multiple and arranged equidistantly along the circumference on the lower end cover, and the diameters of the multiple liquid inlet holes are consistent.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] 1. The hollow main shaft of the motor rotor assembly is used as the flow channel, the motor and the pump are integrated, the power density is large, the working speed can be adjusted by adjusting the power frequency, the high speed is easy to achieve, and the displacement and the range of the lift are large.

[0017] 2. The hollow main shaft used as the flow channel has a large open space, the spiral strip is welded in the hollow main shaft, the spiral strip pushes the liquid at high speed during starting, there is no relative friction between the blade set and the pump body, the pump is not easy to be blocked and has low requirements on the transported liquid, the pump body is not easy to be worn due to the friction between the impurities in the liquid and the pump body in the high-speed working situation, the working life is long, the pump is suitable for various liquids, and the application scenarios are wide.

[0018] 3. The annular differential pressure balancer can make the pressure inside and outside the pump reach dynamic balance in the deep well high-pressure working environment, the dynamic sealing effect is better, the pump can also work stably in the deep well high-pressure working environment, and the working failure caused by the liquid in the working environment penetrating into the pump body through the dynamic sealing part due to the high pressure difference is avoided.

[0019] 4. The whole structure of the present application is simple, the processing difficulty is small, the slender volume is easy to be connected in series, the ground process flow is simple, and the management is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a schematic diagram of the whole structure of the deep well high-speed inner lifting pump of the present application;

[0021] Fig. 2 is a schematic diagram of the structure of the annular differential pressure balancer of the deep well high-speed inner lifting pump of the present application;

[0022] Fig. 3 is an axonometric diagram of the spiral strip of the deep well high-speed inner lifting pump of the present application.

[0023] Fig. 1-1: 1-pump housing, 2-upper end cover, 3-lower end cover, 4-stator and winding, 5-rotor assembly, 501-hollow spindle, 502-spiral strip, 503-center shaft, 504-silicon steel sheet, 505-welding point, 6-threading hole, 7-annular differential pressure balancer, 701-annular cylinder, 702-annular plug, 7021-plug body, 7022-plug seat, 703-cylinder chamber, 704-balance hole, 705-intermediate positioning bearing, 706-outer sliding sealing ring, 707-inner sliding sealing ring, 708-first O-shaped static sealing ring, 709-first O-shaped dynamic sealing ring, 8-liquid inlet hole, 9-return spring, 10-oil supply cavity, 11-oil discharge cavity, 12-upper positioning bearing, 13-lower positioning bearing, 14-second O-shaped dynamic sealing ring, 15-second O-shaped static sealing ring. DETAILED DESCRIPTION

[0024] The technical solutions in the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0025] As shown in Figs. 1-3, a deep-well high-speed inner-lifting pump with dynamic pressure balance dynamic seal comprises a pump housing 1, an upper end cover 2, a lower end cover 3, a stator and winding 4, a rotor assembly 5, a threading hole 6, an annular differential pressure balancer 7, a liquid inlet hole 8, a return spring 9, an oil supply cavity 10, an oil discharge cavity 11, an upper positioning bearing 12, a lower positioning bearing 13, a second O-shaped dynamic sealing ring 14, and a second O-shaped static sealing ring 15.

[0026] In combination with Fig. 1, the pump housing 1 is a cylindrical member, the upper end cover 2 and the lower end cover 3 are annular members and are respectively threadedly connected and fixed to the upper and lower ends of the pump housing 1. The upper end cover 2 can be processed to have the threading hole 6 for leading out and sealing the connecting line of the stator and winding 4 and the power supply. The lower end cover 3 is processed to have the liquid inlet hole 8, the number of the liquid inlet holes 8 can be set to be multiple and arranged equidistantly along the circumference on the lower end cover 3, and the diameters of the multiple liquid inlet holes 8 are kept consistent, so that the liquid in the working environment can enter the space at the bottom of the pump housing 1 through the liquid inlet holes 8 to balance the pressure between the working environment and the space at the bottom of the pump housing 1. The stator and winding 4 are fixed to the upper part of the inner wall of the pump housing 1 and form an alternating current permanent magnet synchronous motor structure with the rotor assembly 5, the motor speed can be increased by increasing the power supply frequency, thereby increasing the lift of the pump, and the traditional pump speed increasing mode through a gear set is improved, so that the present application does not need to consider the loss of the gear set, the service life is improved, and the maintenance cost is reduced.

[0027] In combination with Fig. 2, the annular differential pressure balancer 7 comprises an annular cylinder 701 and an annular plug 702, the annular cylinder 701 has an open end facing downward and is fixed to the lower part of the inner wall of the pump shell 1 through screw thread connection, the annular plug 702 is slidingly and sealingly inserted into the open end of the annular cylinder 701 and forms a cylinder chamber 703 inside, the closed end of the annular cylinder 701 is provided with balance holes 704, the number of the balance holes 704 can be set to be multiple and arranged in equal intervals in the circumferential direction of the closed end of the annular cylinder 701, the diameters of the multiple balance holes 704 are consistent, and the balance holes 704 are used to communicate the cylinder chamber 703 and the lower oil cavity 11 and balance the pressure between the two.

[0028] In combination with Fig. 1, the reset spring 9 is supported between the annular plug 702 and the lower end cover 3, so that the annular plug 702 cannot be dislocated from the annular cylinder 701, and the influence of the self-weight of the annular plug 702 on the operation of the annular differential pressure balancer 7 is eliminated. In order to make the reset spring 9 provide a wider and more stable force platform for the annular plug 702, the annular plug 702 comprises a plug body 7021 and a plug seat 7022, the plug body 7021 is slidingly and sealingly inserted into the open end of the annular cylinder 701, and the plug seat 7022 is formed by the thickening extension of the plug body 7021 from the bottom end inward and outward, thereby ensuring more effective contact between the annular plug 702 and the reset spring 9. The rotor assembly 5 comprises a hollow main shaft 501, a spiral strip 502, a central shaft 503 and a silicon steel sheet 504. The hollow main shaft 501 is coaxially and rotatably installed between the central holes of the upper end cover 2 and the lower end cover 3 through the upper positioning bearing 12 and the lower positioning bearing 13, the hollow main shaft 501 passes through the annular differential pressure balancer 7 and the reset spring 9 below, an intermediate positioning bearing 705 can be additionally arranged between the hollow main shaft 501 and the annular differential pressure balancer 7, and the upper, middle and lower three positioning bearings can well position the hollow main shaft 501 and the entire rotor assembly 5, which helps to ensure the stability of the rotor assembly 5 during high-speed rotation. The silicon steel sheet 504 is fixed to the upper part of the outer wall of the hollow main shaft 501 and gap-fitted with the area where the stator and the winding 4 are located, the upper and lower ends of the silicon steel sheet 504 of the rotor assembly 5 and the cavities between the upper end cover 2 and the annular cylinder 701 form the upper oil cavity 10 and the lower oil cavity 11 respectively, and the upper oil cavity 10 and the lower oil cavity 11 are both filled with cooling lubricating oil. The first O-shaped dynamic sealing ring 709 is arranged between the hollow main shaft 501 and the annular cylinder 701, and the second O-shaped dynamic sealing ring 14 is arranged between the hollow main shaft 501 and the upper end cover 2, so as to avoid the liquid in the working environment from communicating with the cooling lubricating oil in the pump through the gaps of the two rotating connections of the hollow main shaft 501 and causing abnormal operation.

[0029] In combination with Fig. 1 and Fig. 3, the central shaft 503 is coaxially and lengthwise arranged in the hollow main shaft 501, and the spiral strip 502 is arranged around the central shaft 503 and is fixed and connected to the corresponding position of the inner wall of the hollow main shaft 501 through the welding points 505.

[0030] In order to further ensure the sealing performance of the pump, the outer sliding sealing ring 706 and the inner sliding sealing ring 707 are arranged on both sides of the inner wall of the annular cylinder 701 near the open end, the outer sliding sealing ring 706 is in close contact with the outer ring surface of the annular plug 702, and the inner sliding sealing ring 707 is in close contact with the inner ring surface of the annular plug 702. The first O-shaped static sealing ring 708 is arranged between the annular cylinder 701 and the pump shell 1, so as to prevent the liquid in the working environment from communicating with the cooling lubricating oil in the pump through the sliding connection position and the threaded connection gap of the annular differential pressure balancer 7, and causing working abnormity. The second O-shaped static sealing ring 15 is arranged between the upper end cover 2 and the pump shell 1, so as to prevent the liquid in the working environment from entering the pump body through the threaded connection gap between the pump shell 1 and the upper end cover 2, and causing working abnormity.

[0031] In addition, as shown in FIG. 1, the lower end surface of the lower end cover 3 is preferably a tapered surface with a thickness gradually decreasing from the edge to the center hole, so that the flow rate change caused by the impact of the transported liquid and impurities on the lower end surface of the lower end cover 3 when entering from the lower end of the hollow main shaft 501 is more gentle, and the flow rate is increased.

[0032] The deep well high-speed inner lifting pump is a mechanical device for transporting fluid or pressurizing fluid by integrating the motor and the pump body, which can be used for, but is not limited to, lifting oil and gas in the oil well. The hollow main shaft 501 serves as a flow channel to transport the liquid from the lower end to the upper end, and the stator and winding 4 and the rotor assembly 5 are basic components of the motor, which have the conventional structure and will not be described in detail. When the motor part is started, the rotor assembly 5 rotates at a high speed to suck the liquid from the lower end of the hollow main shaft 501, which is lifted by the spiral strip 502, and finally discharged from the upper end of the hollow main shaft 501.

[0033] When entering the high-pressure working environment, the liquid in the working environment enters the space between the annular differential pressure balancer 7 and the lower end cover 3 in the bottom of the pump shell 1 through the liquid inlet hole 8 of the lower end cover 3, and the pressure between the space below the annular differential pressure balancer 7 and the working environment is balanced. When the pressure of the space below the annular differential pressure balancer 7 is greater than the pressure of the space in the pump composed of the cylinder chamber 703, the upper oil cavity 10, the lower oil cavity 11 and the gap between the stator and winding 4 and the rotor assembly 5, the annular plug 702 will rise under the action of the pressure difference, thereby reducing the space in the cylinder chamber 703 and increasing the pressure, until the annular plug 702 stops moving when the pressure is equal to the pressure of the working environment, and the pressure of the space in the pump and the space outside the pump is dynamically balanced, that is, the pressure of the inner and outer sides of the first O-shaped dynamic sealing ring 709 and the second O-shaped dynamic sealing ring 14 is balanced, so that the dynamic sealing effect is optimal, and leakage at the dynamic sealing position in the high-pressure environment is avoided.

[0034] Compared with the traditional pump structure, the hollow spindle 501 internally welded with the spiral strip 502 is adopted in the application, so that the flow channel of the pump is simplified and completely open, and the requirement for the transported liquid is extremely low, and the impurities and sundries in the liquid can be directly discharged along the hollow spindle 501, so that the failure of sundries blocking the pump is avoided, the spiral strip 502 is used to lift the working mode of the circulating liquid, and in the case of high-speed operation, the friction between the impurities, sundries, blades and the pump body will not cause the wear of the water pump, and the water pump can work for a long time at high speed. In addition, the annular differential pressure balancer 7 is adopted in the application, so that the pressure inside and outside the pump can reach dynamic balance through the annular differential pressure balancer 7, the negative influence of easy leakage caused by the pressure difference on both sides of the dynamic seal is avoided, and the dynamic seal reaches the most ideal state.

[0035] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0036] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

Claims

1. A dynamically pressure balanced, mechanically sealed deep-well high-speed internal lift pump characterized by: The utility model provides a kind of centrifugal pump, including pump shell (1), upper end cover (2), lower end cover (3), stator and winding (4), rotor assembly (5), annular differential pressure balancer (7) and reset spring (9), the pump shell (1) is cylindrical member, the upper end cover (2) and the lower end cover (3) are annular member and are respectively fixed with pump shell (1) upper and lower two ends thread connection, lower end cover (3) is processed and is provided with inlet hole (8), the stator and winding (4) are fixed on the upper portion of the inner wall of pump shell (1), the annular differential pressure balancer (7) includes annular cylinder (701) and annular plug (702), the opening end of annular cylinder (701) faces down and its outer wall is fixed with the lower portion of the inner wall of pump shell (1) thread connection, the annular plug (702) is slidably sealed and inserted in the opening end of annular cylinder (701) and forms cylinder chamber (703) inside, annular cylinder (701) closed end is processed and is provided with balance hole (704), the reset spring (9) is supported between annular plug (702) and lower end cover (3), the rotor assembly (5) includes hollow main shaft (501), spiral strip (502), center shaft (503) and silicon steel sheet (504), the hollow main shaft (501) is coaxially rotatably installed between the center hole of upper end cover (2) and lower end cover (3), the silicon steel sheet (504) is fixed on the upper portion of the outer wall of hollow main shaft (501) and is gap matched with the area where stator and winding (4) are located, first O type dynamic sealing ring (709) is arranged between hollow main shaft (501) and annular cylinder (701), second O type dynamic sealing ring (14) is arranged between hollow main shaft (501) and upper end cover (2), the center shaft (503) is coaxially and longitudinally arranged in hollow main shaft (501), spiral strip (502) is processed and arranged around center shaft (503), the edge of spiral strip (502) is connected and fixed with the corresponding position of the inner wall of hollow main shaft (501) by welding point (505).

2. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The lower end surface of the lower end cover (3) is tapered, with the thickness gradually decreasing from the edge to the center hole.

3. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1 or 2, characterized in that: The upper and lower ends of the silicon steel sheet (504) of the rotor assembly (5) form an upper oil cavity (10) and a lower oil cavity (11) with the cavities between the upper end cover (2) and the annular cylinder (701), respectively, and the upper oil cavity (10) and the lower oil cavity (11) are filled with cooling lubricating oil.

4. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The annular plug (702) includes a plug body (7021) and a plug seat (7022), the plug body (7021) is slidably sealed and inserted in the opening end of the annular cylinder (701), and the plug seat (7022) is formed by the thickening of the plug body (7021) bottom end extending inward and outward.

5. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The upper end cover (2) is processed to have a threading hole (6) for leading out the connecting wire of the stator and winding (4) and the power supply and sealing treatment.

6. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The outer sliding sealing ring (706) and the inner sliding sealing ring (707) are arranged on both sides of the inner wall of the annular cylinder (701) adjacent to the opening end, respectively, the outer sliding sealing ring (706) is in close contact with the outer ring surface of the annular plug (702), and the inner sliding sealing ring (707) is in close contact with the inner ring surface of the annular plug (702).

7. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The first O-shaped static sealing ring (708) is arranged between the annular cylinder (701) and the pump shell (1).

8. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The second O-shaped static sealing ring (15) is arranged between the upper end cover (2) and the pump shell (1).

9. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The balance holes (704) are multiple and arranged in equal intervals in the circumferential direction at the closed end of the annular cylinder (701), and the diameters of the multiple balance holes (704) are consistent.

10. A deep-well high-speed inner-lift pump with dynamic pressure balancing and dynamic seal according to claim 1, characterized in that: The liquid inlet holes (8) are multiple and arranged in equal intervals in the circumferential direction on the lower end cover (3), and the diameters of the multiple liquid inlet holes (8) are consistent.

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