Balanced deepwater high-pressure oil-immersed submersible motor

Abstract

The application discloses a balanced deepwater high-pressure oil-immersed submersible motor, and belongs to the technical field of motors. The balanced deepwater high-pressure oil-immersed submersible motor comprises a casing, a rotating shaft, a stator assembly and an end cover. The end cover is axially divided into a main sealing cavity and an isolation cavity in series. A pressure balancing device is arranged on the outer side of the end cover. In the application, the two-stage series chamber layout of the main sealing cavity and the isolation cavity is adopted. The main sealing cavity serves as the first protective barrier for blocking seawater. The isolation cavity serves as a redundant protection intermediate chamber. Even if a trace of seawater leakage occurs in the main sealing cavity, the seawater can only enter the isolation cavity and cannot directly contact the core components in the main oil-immersed cavity. The differential first piston cylinder assembly and the pressure-following second piston cylinder assembly are matched, so that the internal pressure of the isolation cavity and the main oil-immersed cavity can be automatically maintained to be slightly higher than the ambient seawater pressure at all times. The double protection is formed, seawater reverse infiltration into the motor inner cavity is avoided from the source, and the reliability of the motor operation under the deep-sea high-pressure working condition is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and specifically to a balanced deep-sea high-pressure oil-immersed submersible motor. Background Technology

[0002] Oil-immersed submersible motors are the core power components of deep-sea exploration and underwater operation equipment. They are widely used in deep-sea resource exploration, underwater robots, marine scientific research and other fields. When working, the whole machine is immersed in the seawater environment. It relies on internal insulating cooling oil to achieve motor insulation, cooling and internal and external pressure balance. Its sealing protection and pressure balance capabilities directly determine the service stability and service life of underwater equipment.

[0003] Existing oil-immersed submersible motors cannot maintain stable internal pressure in the motor cavity for long periods, and are prone to seawater seeping back into the motor cavity, making it difficult to meet the requirements for long-term reliable operation under deep-sea high-pressure conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a balanced deep-water high-pressure oil-immersed submersible motor.

[0005] The technical solution adopted by this invention is as follows: This application provides a balanced deep-sea high-pressure oil-immersed submersible motor, including a housing, a rotating shaft, a stator assembly, and an end cover fixed to the front end of the housing; the interior of the housing forms a sealed main oil immersion chamber, and the stator assembly and the rotating shaft are both installed in the main oil immersion chamber and immersed in the insulating cooling oil filled in the main oil immersion chamber; the end cover is divided into an independent isolation chamber and a main sealing chamber along the axial direction of the rotating shaft, the isolation chamber being located between the main oil immersion chamber and the main sealing chamber; a pressure balancing device is provided on the outside of the end cover, the pressure balancing device including a first piston cylinder assembly and a second piston cylinder assembly, used to automatically maintain the internal pressure of the isolation chamber always higher than the ambient seawater pressure. The first piston cylinder assembly includes a first cylinder body and a first piston. The first cylinder body includes a first cylindrical section and a second cylindrical section coaxially connected. The inner diameter of the first cylindrical section is larger than the inner diameter of the second cylindrical section. The end of the second cylindrical section is connected to an isolation chamber. The end of the first cylindrical section is connected to the external seawater environment. The first piston includes a large piston plate that slides and seals with the inner wall of the first cylindrical section, a small piston plate that slides and seals with the inner wall of the second cylindrical section, and a connecting column coaxially fixed between the large piston plate and the small piston plate. The second piston cylinder assembly includes a second cylinder body and a second piston. The second piston is slidably and sealably installed inside the second cylinder body. The first chamber of the second cylinder body is connected to the main oil immersion chamber, and its second chamber is connected to the isolation chamber.

[0006] In some embodiments, a dynamic sealing assembly is provided between the rotating shaft and the main sealing cavity. The dynamic sealing assembly includes a rotating ring and a stationary ring. The stationary ring is fixed to the inner wall of the main sealing cavity. The rotating ring rotates synchronously with the rotating shaft. A helical blade is provided on the rotating shaft in the main sealing cavity, located in front of the rotating ring. A cavity is formed between the helical blade and the rotating ring. A compensation cylinder is provided at the rear end of the housing. The compensation cylinder is filled with insulating cooling oil. The compensation cylinder is provided with a first pipe connected to the cavity. The helical blade is used to transport the insulating cooling oil in the compensation cylinder to the cavity by rotation. A wedge-shaped dynamic pressure groove is provided on the sealing end face of the rotating ring, which is arranged radially inclined. The wedge-shaped dynamic pressure groove is used to form a dynamic pressure oil film between the sealing ends of the rotating ring and the stationary ring.

[0007] In some embodiments, the system further includes a pressure pre-regulating cylinder, which has a first piston chamber, a second piston chamber, and a third piston chamber arranged in parallel, with their diameters increasing sequentially. Each piston chamber has a corresponding piston head. One end of the pressure pre-regulating cylinder is provided with a sea-access port that communicates with the external seawater environment. The same end of the first, second, and third piston chambers is connected to the sea-access port. The other end of the first piston chamber is connected to the inner cavity of the main oil immersion chamber and the compensation cylinder, respectively. The other end of the second piston chamber is connected to the inner cavity of the main oil immersion chamber, the compensation cylinder, and the isolation chamber, respectively. The other end of the third piston chamber is connected to the inner cavity of the main oil immersion chamber and the compensation cylinder, respectively. A one-way throttle valve is provided on the pipeline connecting the second piston chamber and the isolation chamber.

[0008] In some embodiments, a breathing suppression cylinder is further included, the breathing suppression cylinder comprising an independent oil storage tank, a first breathing tank, and a second breathing tank; The oil storage tank is connected to the main oil immersion chamber via a second pipe, to the inner cavity of the compensation cylinder via a third pipe, to the first breathing tank via a fourth pipe, and to the second breathing tank via a fifth pipe. A first one-way valve is installed on the second pipe near the main oil immersion chamber, with the first one-way valve having a passageway towards the main oil immersion chamber. A second one-way valve is installed on the fourth pipe near the oil storage tank, with the second one-way valve having a passageway towards the first breathing tank. A third one-way valve is installed on the fifth pipe near the oil storage tank, with the third one-way valve having a passageway towards the second breathing tank. The first breathing tank is connected to the main oil immersion chamber through the sixth pipe and to the second breathing tank through the seventh pipe; a fourth one-way valve is provided on the seventh pipe near the first breathing tank, and the fourth one-way valve is open to the second breathing tank. The second breathing tank is connected to the isolation chamber through the eighth pipe and to the internal flow channel of the pressure pre-regulating cylinder through the ninth pipe.

[0009] In some embodiments, the output end of the rotating shaft is provided with a stepped shaft, and a main sealing structure is provided between the stepped shaft and the main sealing cavity. The main sealing structure includes a first shaft portion, a stepped portion, and a second shaft portion. The diameter of the first shaft portion is larger than the diameter of the second shaft portion. The main sealing structure includes a front cover, a bearing, and a rear cover. The bearing is provided with a second shaft portion, and its end abuts against the stepped portion. A flange portion is provided on the end cover. The front cover and the rear cover are connected to the front and rear ends of the flange portion and clamp and fix the front and rear ends of the bearing. A first sealing structure is provided between the front cover and the second shaft portion, and a second sealing structure is provided between the rear cover and the first shaft portion.

[0010] In some embodiments, the stationary ring is provided with a sealing step, the rotating ring is provided with a sealing end face adapted to the sealing step, the inner ring of the rotating ring is provided with a guide groove on the side near the helical blade, the rotating shaft is provided with a guide protrusion corresponding to the guide groove, the rotating ring has an axial floating space relative to the rotating shaft, an elastic preload is provided on its back, and a third sealing structure is provided between the inner ring of the rotating ring near the isolation cavity and the rotating shaft.

[0011] In some embodiments, the isolation cavity includes an isolation plate near the rotating ring. A rotary sealing structure is provided between the inner ring of the isolation plate and the rotating shaft. A push ring portion is provided on the back of the rotating ring. A through hole is provided on the isolation plate corresponding to the push ring portion. A push block is slidably disposed in the through hole. A fourth sealing structure is provided between the outer peripheral wall of the push block and the through hole. The end faces of the push block that abut against the push ring portion are all provided with arc-shaped surfaces. The insulating cooling oil in the isolation cavity directly acts on the end of the push block to provide it with auxiliary pre-tightening force.

[0012] In some embodiments, the second breathing tank is provided with a buffer damping orifice plate inside, the ninth pipe is sealed and connected to the oil-side internal convergence channel of the first piston chamber, the second piston chamber, and the third piston chamber in the pressure pre-regulating cylinder, and a constant throttling orifice is provided at the connection between the eighth pipe and the isolation chamber; the second breathing tank receives the dynamic pressure fluctuations of the pressure pre-regulating cylinder through the ninth pipe, and after being stabilized by the buffer damping orifice plate, outputs stable compensation pressure to the isolation chamber through the eighth pipe.

[0013] The beneficial effects of this invention are as follows: This invention employs a two-stage series chamber layout of a main sealing chamber and an isolation chamber. The main sealing chamber serves as the first protective barrier against seawater, while the isolation chamber acts as a redundant protective intermediate chamber. Even if a small amount of seawater leaks from the main sealing chamber, it can only enter the isolation chamber and will not directly contact the core components of the motor within the main oil-immersed chamber. Furthermore, through the cooperation of a differential first piston cylinder assembly and a pressure-following second piston cylinder assembly, the internal pressure of both the isolation chamber and the main oil-immersed chamber can be automatically maintained at a slightly higher level than the ambient seawater pressure. This constitutes a double protection, fundamentally preventing seawater from seeping back into the motor's internal cavity and significantly improving the reliability of motor operation under deep-sea high-pressure conditions. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0015] Figure 1 This is a schematic diagram of a balanced deep-water high-pressure oil-immersed submersible motor according to the present invention. Figure 1 ; Figure 2 This is a partial schematic diagram of a balanced deep-water high-pressure oil-immersed submersible motor according to the present invention. Figure 1 ; Figure 3 This is a partial schematic diagram of a balanced deep-water high-pressure oil-immersed submersible motor according to the present invention. Figure 2 ; Figure 4 This is a schematic diagram of a balanced deep-water high-pressure oil-immersed submersible motor according to the present invention. Figure 2 ; Figure 5 for Figure 3 Enlarged view of point A in the middle; Figure 6 for Figure 3 Enlarged view of point B in the middle. Detailed Implementation

[0016] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0017] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "longitudinal", "lateral", "radial", "length", "width", "thickness", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element or component to have a specific orientation, or to be constructed and operated in a specific orientation.

[0018] It should be noted that the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are only used to distinguish different components and should not be construed as limiting the embodiments of this application.

[0019] It should be noted that the terms "installation," "setup," "equipped with," "connection," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two devices, components, or parts.

[0020] It should be noted that the terms "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "in some embodiments," "exemplarily," and "for example" is intended to present related concepts in a specific manner, meaning that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the above terms in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0021] Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] Regarding the accompanying drawings of this application, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not necessarily drawn to scale.

[0023] Existing deep-sea oil-immersed submersible motors are unable to maintain stable internal pressure under long-term high-pressure conditions in the deep sea. After pressure imbalance, problems such as seawater infiltration and damage to seals are likely to occur, making it impossible to guarantee long-term reliable operation of the motor.

[0024] Based on the above issues, such as Figures 1 to 6As shown, this invention proposes a balanced deep-water high-voltage oil-immersed submersible motor, including a housing 1, a rotating shaft 2, a stator assembly 3, and an end cover 4 fixed to the front end of the housing 1. The housing 1 forms a sealed main oil immersion chamber 11. The stator assembly 3 and the rotating shaft 2 are both installed in the main oil immersion chamber 11 and immersed in insulating cooling oil filled in the main oil immersion chamber 11. The insulating cooling oil provides insulation protection and efficient cooling for the stator assembly 3 and the rotating shaft 2. The end cover 4 is fixed to the front end of the housing 1 by sealing bolts. One end of the rotating shaft 2 extends out of the end cover 4 as the output end. The end cover 4 is divided into sections along the axial direction of the rotating shaft 2. The isolation chamber 42 and the main sealing chamber 41 are independent of each other. The isolation chamber 42 is located between the main oil immersion chamber 11 and the main sealing chamber 41, forming a two-stage series redundant protective chamber layout. The main sealing chamber 41 serves as the first barrier against seawater infiltration, and the isolation chamber 42 serves as an intermediate redundant protective chamber to prevent seawater from directly contacting the core components of the motor in the main oil immersion chamber 11. A pressure balancing device 5 is provided on the outside of the end cover 4. The pressure balancing device 5 includes a first piston cylinder assembly 51 and a second piston cylinder assembly 52, which are used to automatically maintain the internal pressure of the isolation chamber 42 at a level higher than the ambient seawater pressure, generally only slightly higher than the ambient seawater pressure.

[0025] Further, the first piston cylinder assembly 51 includes a first cylinder body 511 and a first piston 512. The first cylinder body 511 includes a first cylindrical portion 5111 and a second cylindrical portion 5112 coaxially connected. The inner diameter of the first cylindrical portion 5111 is larger than the inner diameter of the second cylindrical portion 5112. The end of the second cylindrical portion 5112 is sealed and connected to the isolation chamber 42, and the end of the first cylindrical portion 5111 is connected to the external seawater environment. The first piston 512 includes a large piston plate 5121 that slides and seals with the inner wall of the first cylindrical portion 5111, a small piston plate 5122 that slides and seals with the inner wall of the second cylindrical portion 5112, and a connecting column 5123 coaxially fixed between the large piston plate 5121 and the small piston plate 5122. The effective pressure-bearing area ratio of the large piston plate 5121 and the small piston plate 5122 is designed to be 1.1~1.3:1. It can be understood that the first cylinder body 511 is provided with a structure to limit the maximum stroke of the first piston 512.

[0026] With this configuration, the external seawater pressure is synchronously transmitted and pressurized into the oil in the isolation chamber 42 by utilizing the variable diameter boosting effect of the differential piston. This ensures that the pressure in the isolation chamber 42 is always 1.1 to 1.3 times that of the seawater pressure, achieving the effect that the pressure in the isolation chamber 42 is always slightly higher than the ambient seawater pressure. This continuously maintains the preset positive pressure difference and forms a stable pressure barrier.

[0027] Furthermore, the second piston cylinder assembly 52 includes a second cylinder body 521 and a second piston 522. The second piston 522 is slidably and sealingly installed inside the second cylinder body 521. The second cylinder body 521 is provided with a structure that limits the maximum stroke of the second piston 522. The first chamber of the second cylinder body 521 is in sealed communication with the main oil immersion chamber 11, and its second chamber is in sealed communication with the isolation chamber 42. Through the sliding follow of the second piston 522, the pressure linkage balance between the main oil immersion chamber 11 and the isolation chamber 42 is achieved, so that the pressure of the main oil immersion chamber 11 is synchronously maintained slightly higher than the ambient seawater pressure, thus preventing seawater from seeping back in at the source. In addition, the pressure of the main oil immersion chamber and the isolation chamber is synchronized without difference, completely avoiding the problem of uneven force on the seal caused by pressure difference between the main oil immersion chamber and the isolation chamber.

[0028] Optionally, a low-stiffness reset buffer spring is provided between the shoulder of the large piston plate 5121 and the first cylinder 5111 and the second cylinder 5112. The initial preload of the reset buffer spring is greater than the maximum sliding friction between the first piston 512 and the cylinder body, and is used to push the first piston 512 to automatically reset towards the seawater side.

[0029] In some embodiments, a dynamic sealing assembly 6 is provided between the rotating shaft 2 and the main sealing cavity 41 as the first core protection against seawater infiltration; the dynamic sealing assembly 6 includes a dynamic ring 61 and a stationary ring 62, the stationary ring 62 is fixed to the inner wall of the main sealing cavity 41 and does not rotate with the rotating shaft 2, while the dynamic ring 61 rotates synchronously with the rotating shaft 2; a helical blade 7 is provided on the rotating shaft 2 inside the main sealing cavity 41, located in front of the dynamic ring 61, the helical blade 7 includes 3-6 blades evenly arranged circumferentially, the helix angle of the blades is set to 15°-25°, the outer diameter of the blades is clearance-fitted with the inner wall of the main sealing cavity 41, and a cavity 71 is formed between the helical blade 7 and the dynamic ring 61; a compensation cylinder 8 is provided at the rear end of the housing 1, the compensation cylinder 8 is filled with the same as the main oil immersion cavity 11 The insulating cooling oil source is provided by the compensation cylinder 8, which is connected to the cavity 71 via a first pipe 81. The spiral blade 7 can rotate synchronously with the rotating shaft 2, forming a stable negative pressure zone in the cavity 71. This allows the insulating cooling oil in the compensation cylinder 8 to be continuously delivered to the cavity 71, providing a stable source of cold oil for the sealing end face. This structure does not require an additional oil pump; it can achieve active oil supply by reusing the rotational power of the rotating shaft. The structure is compact with no additional energy consumption, and the oil supply flow rate is positively correlated with the rotating shaft speed. The higher the speed and the greater the heat generated on the sealing surface, the higher the oil supply flow rate, achieving adaptive lubrication and cooling. At the same time, the oil pushed by the spiral blade to the front end of the main sealing cavity forms a rotating oil barrier, further preventing seawater from penetrating to the sealing end face, thus achieving a dual effect of suction oil supply and pre-blocking water.

[0030] The sealing end face of the rotating ring 61 is provided with a radially inclined wedge-shaped dynamic pressure groove. Eight to twelve wedge-shaped dynamic pressure grooves are evenly distributed circumferentially along the sealing end face of the rotating ring 61. Each wedge-shaped dynamic pressure groove has a converging wedge structure, with the groove depth gradually decreasing from the inner ring to the outer ring. The outer ring is flush with the sealing end face. The inclination direction of the wedge-shaped dynamic pressure groove matches the rotation direction of the rotating ring 61. The wedge-shaped dynamic pressure groove can form a high-pressure dynamic pressure oil film between the sealing ends of the rotating ring 61 and the stationary ring 62. When the rotating ring rotates at high speed with the shaft, it drives the insulating cooling oil in the gap between the sealing end faces into the converging gap of the wedge-shaped dynamic pressure groove. After the oil is squeezed, the pressure rises sharply, forming a high-pressure dynamic pressure oil film with a thickness of micrometers between the sealing end faces. This achieves both isolation and protection of the sealing end faces. The oil film pressure is higher than the external seawater pressure, which can completely block the leakage path of seawater into the isolation cavity and avoid wear caused by direct metal contact. At the same time, the oil film can continuously remove the frictional heat generated by the operation of the sealing surface, significantly extending the service life of the seal.

[0031] Preferably, a circulating oil outlet is provided on the side wall of the cavity 71. The circulating oil outlet is sealed and connected to the inner cavity of the first breathing tank 102 through a circulating return pipe 1016. A control valve, such as a micro-pressure differential relief valve and a one-way return valve, is connected in series on the circulating return pipe 1016. When the pressure inside the cavity 71 exceeds the threshold, the valve group automatically opens. The dynamic oil fluctuations in the cavity 71 are first buffered by the first breathing tank 102 and then flow back to the main oil immersion cavity 11.

[0032] In some embodiments, a pressure pre-adjustment cylinder 9 is further included to adapt to rapid pressure adjustment when the diving depth changes, and to compensate for the response lag of the pressure balancing device 5. The pressure pre-adjustment cylinder 9 has a first piston chamber 91, a second piston chamber 92 and a third piston chamber 93 arranged in parallel, with the diameters of the three chambers increasing sequentially to adapt to different pressure change rates. For example, the inner diameters of the first piston chamber 91, the second piston chamber 92 and the third piston chamber 93 can be set to 20mm, 30mm and 40mm respectively. Preferably, the three piston chambers are arranged in parallel at the same horizontal height.

[0033] Each piston chamber is provided with a corresponding piston head 94 and an elastic element for resetting the piston head 94. The elastic element can be a stainless steel return spring. For example, a partition portion is provided in the piston chamber, and the piston head includes two spaced-apart piston plates and a connecting shaft disposed between the two piston plates. The connecting shaft is slidably disposed along the partition portion. A sealing element is provided between the piston plates and the corresponding chamber wall. The elastic element is disposed between the piston plate near the seawater side and the partition portion to provide an initial reset force for the piston head 94. One end of the pressure pre-adjustment cylinder 9 is provided with a sea-entry port 95 communicating with the external seawater environment. The first piston... The same end of the first piston chamber 91, the second piston chamber 92, and the third piston chamber 93 is connected to the sea-access interface 95 to achieve synchronous transmission of environmental seawater pressure. The other end of the first piston chamber 91 is connected to the inner cavity of the main oil immersion chamber 11 and the compensation cylinder 8, respectively. The other end of the second piston chamber 92 is connected to the inner cavity of the main oil immersion chamber 11, the compensation cylinder 8, and the isolation chamber 42, respectively. The other end of the third piston chamber 93 is connected to the inner cavity of the main oil immersion chamber 11 and the compensation cylinder 8, respectively. A one-way throttle valve is installed on the pipeline connecting the second piston chamber 92 and the isolation chamber 42 to control the on / off state and flow rate of the oil and avoid pressure shock.

[0034] With this configuration, the three piston chambers with increasing diameters correspond to different pressure change thresholds. The smaller the diameter of the piston chamber, the smaller the amount of seawater pressure change required to drive the piston, and the higher the response sensitivity. When the diving depth changes slowly and the seawater pressure fluctuation rate is low, only the small-diameter piston head 94 of the first piston chamber 91 overcomes the elastic force of the elastic element to push a small amount of oil to compensate for the pressure change in the main oil immersion chamber 11, achieving fine pressure regulation without impact. When the diving depth changes rapidly and the seawater pressure fluctuation rate is moderate, the medium-diameter piston head 94 of the second piston chamber 92 moves synchronously, pushing oil to both the main oil immersion chamber 11 and the isolation chamber 42 to quickly compensate for the pressure in the two chambers and match the pressure regulation rhythm of the pressure balancing device 5. When the diving depth changes suddenly and the seawater pressure fluctuates dramatically, the large-diameter piston head 94 of the third piston chamber 93 moves its full stroke, instantly pushing a large flow of oil to the main oil immersion chamber 11 to quickly balance the internal and external pressure difference and prevent the instantaneous pressure difference from exceeding the standard and damaging the seals.

[0035] In summary, the core advantages of this structure are: first, it features graded response pressure regulation, which balances the accuracy of steady-state pressure regulation with the response speed under dynamic conditions, completely compensating for the response lag problem of the differential piston in the pressure balancing device 5 when the pressure changes suddenly; second, it is a fully mechanical passive triggering system that requires no electronic control components and can automatically match the action of the corresponding piston chamber simply by changing the seawater pressure, making it highly reliable and adaptable to the deep-sea environment; and third, it features dual-chamber synchronous compensation, where the second piston chamber 92 can simultaneously replenish pressure to the isolation chamber 42 and the main oil immersion chamber 11, preventing pressure imbalance between the two chambers and forming a double-redundant pressure regulation protection with the pressure balancing device 5.

[0036] In some embodiments, a breathing suppression cylinder 10 is also included to buffer pressure fluctuations caused by thermal expansion and contraction of the oil, while achieving stable control of the oil operating conditions; the breathing suppression cylinder 10 includes an independent oil storage tank 101, a first breathing tank 102 and a second breathing tank 103, with the three tanks isolated to form an independent chamber.

[0037] Specifically, the oil storage tank 101 is connected to the main oil immersion chamber 11 via a second pipe 104, to the inner cavity of the compensation cylinder 8 via a third pipe 105, to the first breathing tank 102 via a fourth pipe 106, and to the second breathing tank 103 via a fifth pipe 107. A first one-way valve 108 is provided at the end of the second pipe 104 near the main oil immersion chamber 11, and the first one-way valve 108 is open to the main oil immersion chamber 11, allowing only the oil storage tank 101 to replenish oil to the main oil immersion chamber 11. A second one-way valve 109 is provided at the end of the fourth pipe 106 near the oil storage tank 101, and the second one-way valve 109 is open to the first breathing tank 102. A third one-way valve 1010 is provided at the end of the fifth pipe 107 near the oil storage tank 101, and the third one-way valve 1010 is open to the second breathing tank 103.

[0038] Furthermore, the first breathing tank 102 is connected to the main oil immersion chamber 11 via the sixth pipe 1011 and to the second breathing tank 103 via the seventh pipe 1012; a fourth one-way valve 1013 is provided at one end of the seventh pipe 1012 near the first breathing tank 102, and the fourth one-way valve 1013 is open to the second breathing tank 103; the second breathing tank 103 is connected to the isolation chamber 42 via the eighth pipe 1014 and to the internal flow channel of the pressure pre-regulating cylinder 9 via the ninth pipe 1015.

[0039] This configuration serves two purposes: First, during thermal expansion of the oil, the heat generated by the motor causes the insulating cooling oil in the main oil immersion chamber 11 to expand, increasing the internal pressure. At this time, the first one-way valve 108 reverses and shuts off, allowing the excess oil to flow into the first breathing tank 102 through the sixth pipe 1011, and then into the second breathing tank 103 through the fourth one-way valve 1013. This achieves redundant oil storage and prevents the seals from overloading due to excessive pressure in the main oil immersion chamber 11. Second, during cooling and expansion of the oil, the oil volume shrinks after the motor stops and cools down, reducing the pressure in the main oil immersion chamber 11. At this time, the oil in the storage tank 101 automatically replenishes the main oil immersion chamber 11 through the first one-way valve 108, while the second one-way valve 109 and the third one-way valve 1010 simultaneously replenish the two breathing tanks, maintaining stable pressure in each chamber and preventing seawater from seeping in due to excessively low pressure.

[0040] In summary, the multi-chamber graded breathing buffer uses the first breathing tank 102 to absorb oil fluctuations caused by normal thermal expansion and contraction, and the second breathing tank 103 to absorb large-flow oil fluctuations caused by changes in diving depth, thus avoiding severe pressure fluctuations between the main oil immersion chamber and the isolation chamber and suppressing the risk of seawater infiltration caused by the motor breathing effect. In some embodiments, the output end of the rotating shaft 2 is provided with a stepped shaft 21, and a main sealing structure is provided between the stepped shaft 21 and the main sealing cavity 41 to form a front-end redundant protection for the output end of the rotating shaft 2; the stepped shaft 21 includes a first shaft portion 211, a stepped portion 212 and a second shaft portion 213, and the diameter of the first shaft portion 211 is larger than the diameter of the second shaft portion 213; the main sealing structure includes a front cover 111, a bearing 112 and a rear cover 113, the bearing 112 is disposed on the second shaft portion 213, and its end is connected to the stepped portion 212. The two parts abut against each other to achieve axial positioning; the end cover 4 is provided with a flange 43, and the front cover 111 and the rear cover 113 are bolted to the front and rear ends of the flange 43, and clamp and fix the front and rear ends of the bearing 112; a first sealing structure 114 is provided between the front cover 111 and the second shaft 213, and a second sealing structure 115 is provided between the rear cover 113 and the first shaft 211. Preferably, both the first sealing structure 114 and the second sealing structure 115 can be lip seals to achieve multiple front-end sealing protection.

[0041] In some embodiments, the stationary ring 62 is provided with a sealing step 621, and the rotating ring 61 is provided with a sealing end face adapted to the sealing step 621. The fitting accuracy of the sealing surface is improved by the step. A guide groove 611 is provided on the inner ring of the rotating ring 61 near the helical blade 7. A guide protrusion 22 is provided on the rotating shaft 2 corresponding to the guide groove 611. The guide protrusion 22 is embedded in the guide groove 611 to realize the circumferential limitation of the rotating ring 61, and at the same time, the rotating ring 61 has axial floating space relative to the rotating shaft 2. An elastic preload member 612, such as a disc spring and a compression spring, is provided on the back of the rotating ring 61 to provide the initial sealing preload force for the rotating ring 61. A third sealing structure 613 is provided between the inner ring of the rotating ring 61 near the isolation cavity 42 and the rotating shaft 2 to prevent oil leakage from the inner ring of the rotating ring 61.

[0042] In some embodiments, the isolation cavity 42 includes an isolation plate 421 near the moving ring 61. The isolation plate 421 is fixed to the inner wall of the end cap 4. The other end of the elastic pre-tightening member 612 abuts against the isolation plate 421. A rotary sealing structure 422 is provided between the inner ring of the isolation plate 421 and the rotating shaft 2 to form an inner seal of the isolation cavity 42. A push ring portion 614 is provided on the back of the moving ring 61. A through hole is opened on the isolation plate 421 corresponding to the push ring portion 614. A push block 12 is slidably disposed in the through hole. A fourth sealing structure 121 is provided between the outer peripheral wall of the push block 12 and the through hole to prevent oil leakage in the isolation cavity 42. The end faces of the push block 12 that abut against the push ring portion 614 are provided with arc-shaped surfaces to reduce mating friction. The insulating cooling oil in the isolation cavity 42 directly acts on the end of the push block 12 to provide it with auxiliary pre-tightening force and realize adaptive adjustment of the sealing and fitting pressure. With this configuration, the pressure in the isolation chamber 42 increases synchronously with the seawater pressure, and the auxiliary pre-tightening force of the push block 12 also increases synchronously, achieving adaptive adjustment of the sealing and bonding pressure under all working conditions. Specifically, when the seawater pressure is higher and the sealing requirement is stronger, the bonding pressure increases synchronously, completely solving the industry pain points of sealing failure under high pressure and excessive wear under low pressure. At the same time, the arc-shaped surface design can prevent the push block from rotating circumferentially when the rotating ring rotates, reducing wear and improving the stability of the compensation structure.

[0043] In some embodiments, a buffer damping orifice plate is provided inside the second breathing tank 103. The ninth pipe 1015 is sealed and connected to the oil-side internal convergence channel of the first piston chamber 91, the second piston chamber 92, and the third piston chamber 93 in the pressure pre-regulating cylinder 9. A constant throttling orifice is provided at the connection between the eighth pipe 1014 and the isolation chamber 42. The second breathing tank 103 receives dynamic pressure fluctuations from the pressure pre-regulating cylinder 9 through the ninth pipe 1015. After being stabilized by the buffer damping orifice plate, a stable compensation pressure is output to the isolation chamber 42 through the eighth pipe 1014, forming a synergistic pressure stabilization effect with the pressure balancing device 5. With this configuration, the dual damping design of the buffer damping orifice plate and the constant throttling orifice can effectively filter out the pressure pulsations caused by the operation of the pressure pre-regulating cylinder, outputting a stable compensation pressure without fluctuations to the isolation chamber. This synergizes with the precise pressure stabilization of the pressure balancing device, preventing pressure shocks from damaging the dynamic pressure oil film between the moving ring and the stationary ring, and further improving sealing reliability.

[0044] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that the requirements of this application encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this application and are within the spirit and scope of the exemplary embodiments of this application.

[0045] Furthermore, it should be understood that in the foregoing description of the embodiments of this application, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this application. That is, the embodiments in this application can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0046] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments of this application. Other modified embodiments are also within the scope of this application. Therefore, the embodiments disclosed herein are merely examples and not limitations. Those skilled in the art can adopt alternative configurations to implement the applications in this application based on the embodiments in this application. Therefore, the embodiments of this application are not limited to the embodiments precisely described in the application.

Claims

1. A balanced deep-water high-pressure oil-immersed submersible motor, characterized in that, The device includes a housing, a rotating shaft, a stator assembly, and an end cap fixed to the front end of the housing. The housing forms a sealed main oil-immersed chamber, in which the stator assembly and rotating shaft are installed and submerged in insulating cooling oil. The end cap is divided along the axial direction of the rotating shaft into an independent isolation chamber and a main sealing chamber. The isolation chamber is located between the main oil-immersed chamber and the main sealing chamber. A pressure balancing device is provided on the outside of the end cap, comprising a first piston cylinder assembly and a second piston cylinder assembly, used to automatically maintain the pressure inside the isolation chamber above the ambient seawater pressure. The first piston cylinder assembly includes a first cylinder body and a first piston. The first cylinder body includes a first cylindrical section and a second cylindrical section coaxially connected. The inner diameter of the first cylindrical section is larger than the inner diameter of the second cylindrical section. The end of the second cylindrical section is connected to the isolation chamber. The end of the first cylindrical section is connected to the external seawater environment. The first piston includes a large piston plate that slides and seals with the inner wall of the first cylindrical section, a small piston plate that slides and seals with the inner wall of the second cylindrical section, and a connecting column coaxially fixed between the large piston plate and the small piston plate. The second piston cylinder assembly includes a second cylinder body and a second piston. The second piston is slidably and sealably installed inside the second cylinder body. The first chamber of the second cylinder body is connected to the main oil immersion chamber, and its second chamber is connected to the isolation chamber.

2. The balanced deep-water high-pressure oil-immersed submersible motor according to claim 1, characterized in that, A dynamic sealing assembly is provided between the rotating shaft and the main sealing cavity. The dynamic sealing assembly includes a rotating ring and a stationary ring. The stationary ring is fixed to the inner wall of the main sealing cavity. The rotating ring rotates synchronously with the rotating shaft. A spiral blade is provided on the rotating shaft in the main sealing cavity, located in front of the rotating ring. A cavity is formed between the spiral blade and the rotating ring. A compensation cylinder is provided at the rear end of the housing. The compensation cylinder is filled with insulating cooling oil. The compensation cylinder is provided with a first pipe connected to the cavity. The spiral blade is used to transport the insulating cooling oil in the compensation cylinder to the cavity by rotation. A wedge-shaped dynamic pressure groove is provided on the sealing end face of the rotating ring, which is inclined radially. The wedge-shaped dynamic pressure groove is used to form a dynamic pressure oil film between the sealing ends of the rotating ring and the stationary ring.

3. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 2, characterized in that, It also includes a pressure pre-regulating cylinder, which has a first piston chamber, a second piston chamber, and a third piston chamber arranged in parallel, with their diameters increasing sequentially. Each piston chamber has a corresponding piston head. One end of the pressure pre-regulating cylinder is provided with a sea-access interface that communicates with the external seawater environment. The same end of the first piston chamber, the second piston chamber, and the third piston chamber is connected to the sea-access interface. The other end of the first piston chamber is connected to the inner cavity of the main oil immersion chamber and the compensation cylinder, respectively. The other end of the second piston chamber is connected to the inner cavity of the main oil immersion chamber, the compensation cylinder, and the isolation chamber, respectively. The other end of the third piston chamber is connected to the inner cavity of the main oil immersion chamber and the compensation cylinder, respectively. A one-way throttle valve is provided on the pipeline connecting the second piston chamber and the isolation chamber.

4. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 3, characterized in that, It also includes a breathing suppression cylinder, which comprises an independent oil storage tank, a first breathing tank, and a second breathing tank; The oil storage tank is connected to the main oil immersion chamber via a second pipe, to the inner cavity of the compensation cylinder via a third pipe, to the first breathing tank via a fourth pipe, and to the second breathing tank via a fifth pipe. A first one-way valve is installed on the second pipe near the main oil immersion chamber, with the first one-way valve having a passageway towards the main oil immersion chamber. A second one-way valve is installed on the fourth pipe near the oil storage tank, with the second one-way valve having a passageway towards the first breathing tank. A third one-way valve is installed on the fifth pipe near the oil storage tank, with the third one-way valve having a passageway towards the second breathing tank. The first breathing tank is connected to the main oil immersion chamber through the sixth pipe and to the second breathing tank through the seventh pipe; a fourth one-way valve is provided on the seventh pipe near the first breathing tank, and the fourth one-way valve is open to the second breathing tank. The second breathing tank is connected to the isolation chamber through the eighth pipe and to the internal flow channel of the pressure pre-regulating cylinder through the ninth pipe.

5. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 2, characterized in that, The output end of the rotating shaft is provided with a stepped shaft, and a main sealing structure is provided between the stepped shaft and the main sealing cavity. The main sealing structure includes a first shaft portion, a stepped portion and a second shaft portion. The diameter of the first shaft portion is larger than the diameter of the second shaft portion. The main sealing structure includes a front cover, a bearing and a rear cover. The bearing is provided with a second shaft portion, and its end abuts against the stepped portion. A flange portion is provided on the end cover. The front cover and the rear cover are connected to the front and rear ends of the flange portion and clamp and fix the front and rear ends of the bearing. A first sealing structure is provided between the front cover and the second shaft portion, and a second sealing structure is provided between the rear cover and the first shaft portion.

6. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 2, characterized in that, The stationary ring is provided with a sealing step, and the rotating ring is provided with a sealing end face adapted to the sealing step. The inner ring of the rotating ring is provided with a guide groove on the side near the spiral blade. The rotating shaft is provided with a guide protrusion corresponding to the guide groove. The rotating ring has an axial floating space relative to the rotating shaft. An elastic pre-tightening member is provided on its back. A third sealing structure is provided between the inner ring of the rotating ring and the rotating shaft on the side near the isolation cavity.

7. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 6, characterized in that, The isolation chamber includes an isolation plate near the rotating ring. A rotary sealing structure is provided between the inner ring of the isolation plate and the rotating shaft. A push ring is provided on the back of the rotating ring. A through hole is provided on the isolation plate corresponding to the push ring. A push block is slidably disposed in the through hole. A fourth sealing structure is provided between the outer peripheral wall of the push block and the through hole. The end faces of the push block that abut against the push ring are all provided with arc-shaped surfaces. The insulating cooling oil in the isolation chamber directly acts on the end of the push block to provide it with auxiliary pre-tightening force.

8. A balanced deep-water high-pressure oil-immersed submersible motor according to claim 4, characterized in that, The second breathing tank is equipped with a buffer damping orifice plate inside. The ninth pipe is sealed and connected to the oil-side internal convergence channel of the first piston chamber, the second piston chamber, and the third piston chamber in the pressure pre-regulating cylinder. A constant throttling orifice is provided at the connection between the eighth pipe and the isolation chamber. The second breathing tank receives the dynamic pressure fluctuations of the pressure pre-regulating cylinder through the ninth pipe. After being stabilized by the buffer damping orifice plate, it outputs stable compensation pressure to the isolation chamber through the eighth pipe.

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