Submersible motor protector and submersible screw pump

Abstract

The present application relates to the technical field of submersible pumps, and discloses a submersible motor protector and a submersible screw pump. The submersible motor protector includes a housing, a transmission shaft, a first capsule assembly, a first one-way valve, and a second capsule assembly. The transmission shaft is passed through the housing. The first capsule assembly includes a first capsule sleeved on the transmission shaft, and a first chamber is provided between the first capsule and the transmission shaft. The second capsule assembly includes a second capsule sleeved on the transmission shaft, a serpentine pipe, and a second one-way valve, and a second chamber is provided between the second capsule and the transmission shaft. The first one-way valve connects the first chamber and the second chamber. One end of the serpentine pipe is connected to the second chamber, and the other end of the serpentine pipe is connected to the second one-way valve. The first one-way valve is used to allow the fluid in the first chamber to flow to the second chamber, and the second one-way valve is used to discharge the fluid in the serpentine pipe. In the above manner, the embodiment of the present application can delay the time for the well fluid to enter the hydraulic balancing device and improve the service life of the submersible screw pump.

Description

Technical Field

[0001] The present application relates to the technical field of submersible pumps, and in particular to a submersible motor protector and a submersible screw pump. Background Art

[0002] Submersible screw pump units work in the underground environment of oil fields, and their reliability requirements are extremely high. The protector is an important part of the intelligent oil production system, which is divided into an upper protector, a high thrust bearing assembly and a lower protector. The upper protector is connected to the pump body through a universal joint, and the lower protector is connected to the motor.

[0003] The upper protector is equipped with a hydraulic balance device, which stores lubricating fluid. The hydraulic balance device is designed to provide sufficient lubrication for the high thrust bearing assembly and balance the pressure inside and outside the downhole housing. The hydraulic balance device is connected to the outside world through a liquid channel and a pressure relief port. The liquid channel is equipped with a one-way valve to prevent well fluid from contaminating the lubricating fluid.

[0004] However, when the internal temperature of the unit rises and causes the lubricating fluid in the hydraulic balance device to expand thermally, the one-way valve may still open to discharge the lubricating fluid, which may cause the well fluid to exchange with the lubricating fluid, thereby contaminating the lubricating fluid and causing impurities such as water to enter the high-thrust bearing assembly, seriously affecting the bearing life. Summary of the invention

[0005] In view of the problems existing in the background technology, the purpose of the present application is to provide a submersible motor protector and a submersible screw pump, which overcome the above problems or at least partially solve the above problems.

[0006] According to the first aspect of the present application, a submersible motor protector is provided, comprising a housing, a transmission shaft, a first capsule assembly, a first one-way valve, and a second capsule assembly. The transmission shaft is inserted into the housing. The first capsule assembly comprises a first capsule, the first capsule is arranged in the housing and sleeved on the transmission shaft, and a first chamber is provided between the first capsule and the transmission shaft. The first one-way valve is connected to the first chamber. The second capsule assembly comprises a second capsule, a serpentine pipe, and a second one-way valve, the second capsule is arranged in the housing and sleeved on the transmission shaft, a second chamber is provided between the second capsule and the transmission shaft, the second chamber is connected to the first one-way valve, one end of the serpentine pipe is connected to the second chamber, and the other end of the serpentine pipe is connected to the second one-way valve. Wherein, the first one-way valve is used to allow the fluid in the first chamber to flow to the second chamber, and the second one-way valve is used to allow the fluid in the serpentine pipe to be discharged.

[0007] In one or more optional embodiments above, the serpentine pipeline includes a serpentine tube unit, and the serpentine tube unit includes a first straight segment, a bent segment, and a second straight segment. The first straight segment and the second straight segment extend along the axial direction of the transmission shaft, respectively, and the first straight segment and the second straight segment are arranged at intervals along the radial direction of the transmission shaft. One end of the first straight segment facing the first capsule is connected to one end of the bent segment, and one end of the second straight segment facing the first capsule is connected to the other end of the bent segment. The other end of the first straight segment is connected to the second chamber, and the other end of the second straight segment is connected to the second one-way valve.

[0008] In one or more optional embodiments above, the serpentine pipe comprises at least two serpentine pipe units and at least one connecting segment, each of which is connected between two corresponding adjacent serpentine pipe units. One end of the connecting segment is connected to the first straight line segment of a corresponding serpentine pipe unit, and the other end of the connecting segment is connected to the second straight line segment of another corresponding serpentine pipe unit.

[0009] In one or more of the above optional embodiments, the submersible motor protector includes a first inner joint, which is arranged in the shell and sleeved on the transmission shaft, the first inner joint is connected between the first capsule assembly and the second capsule assembly, and the first one-way valve is installed on the first inner joint.

[0010] In one or more optional embodiments above, the second capsule assembly further includes a second inner joint, which is disposed in the shell and sleeved on the transmission shaft, and the second inner joint is connected to an end of the second capsule facing away from the first capsule.

[0011] In one or more optional embodiments above, the second inner joint is provided with a second communicating hole, the second one-way valve is arranged in the second communicating hole, and the other end of the serpentine pipe is connected with one end of the second communicating hole toward the second capsule.

[0012] In one or more optional embodiments above, the number of the second capsule assemblies is at least two, and the at least two second capsule assemblies are sequentially arranged along the axial direction of the transmission shaft. In each adjacent two second capsule assemblies, the second communication hole of one second capsule assembly close to the first capsule is connected to the second capsule of the other second capsule assembly.

[0013] In one or more optional embodiments above, the second capsule assembly further comprises a support sleeve, the support sleeve is disposed in the second chamber and sleeved outside the transmission shaft, and one end of the support sleeve is connected to the second inner joint. In each adjacent two second capsule assemblies, the support sleeve of one second capsule assembly away from the first capsule is connected to the second inner joint of the other second capsule assembly.

[0014] In one or more of the above optional embodiments, it also includes a rotating bearing, which is arranged between the second inner joint and the transmission shaft; and / or it also includes an anti-rotation connecting member, which respectively connects the second inner joint and the shell; and / or it also includes a sealing ring, which is connected between the second inner joint and the transmission shaft.

[0015] In one or more optional embodiments above, the number of the second capsule components is at least two, and at least two second capsule components are sequentially arranged along the axis direction of the transmission shaft. Every two adjacent second capsule components are connected to each other, and one of the second capsule components is connected to the first one-way valve.

[0016] In one or more optional embodiments above, a third chamber is provided between the shell and the first capsule, and the shell is provided with a first through hole, which respectively connects the outside of the shell and the third chamber; and / or a fourth chamber is provided between the shell and the second capsule, and the shell is further provided with a second through hole, which respectively connects the outside of the shell and the fourth chamber.

[0017] In one or more optional embodiments above, a fourth chamber is provided between the shell and the second capsule, and the shell is provided with a second through hole, the second through hole respectively communicating with the outside of the shell and the fourth chamber. The submersible motor protector further includes a two-way valve, and the two-way valve is installed in the second through hole.

[0018] In one or more optional embodiments above, the shell includes a first shell, a second shell, and a first adapter, and two ends of the first adapter are respectively connected to the first shell and the second shell. The first capsule is arranged in the first shell, and one end of the first capsule facing the second capsule is connected to the first adapter. The second capsule is arranged in the second shell, and one end of the second capsule facing the first capsule is connected to the first adapter.

[0019] In one or more optional embodiments above, the first adapter is sleeved on the transmission shaft, a liquid passage is provided between the first adapter and the transmission shaft, and two ends of the liquid passage are respectively connected to the first chamber and the first one-way valve.

[0020] In one or more optional embodiments above, the first capsule assembly further includes a protective tube, one end of which is connected to the first adapter, the first capsule is sleeved outside the protective tube, and the first capsule and the protective tube are enclosed to form the first chamber. The protective tube is sleeved outside the transmission shaft, and a lubrication channel is provided between the protective tube and the transmission shaft, and the lubrication channel is connected to the first chamber and the liquid passage, respectively.

[0021] According to a second aspect of the present application, a submersible screw pump is provided, comprising the submersible motor protector as described above.

[0022] The beneficial effects of the embodiments of the present application are as follows: the submersible motor protector provided by the embodiments of the present application, by setting a second chamber in the flow path between the first chamber and the second one-way valve, is conducive to delaying the time for the well fluid to enter the first chamber, and further setting a serpentine pipe in the second chamber, further delaying the time for the well fluid to finally enter the first chamber, thereby improving the service life of the submersible screw pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0024] Figure 1 A three-dimensional diagram of a submersible motor protector provided in an embodiment of the present application;

[0025] Figure 2 A cross-sectional view of a submersible motor protector provided in an embodiment of the present application;

[0026] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0027] Figure 4 A schematic diagram of a serpentine pipeline provided in an embodiment of the present application;

[0028] Figure 5 for Figure 4 Sectional view at EE in the middle;

[0029] Figure 6 for Figure 2 The enlarged view of point B in the middle;

[0030] Figure 7 A partial exploded view of a submersible motor protector provided in an embodiment of the present application;

[0031] Figure 8 for Figure 2 Enlarged view of point C in the middle;

[0032] Fig. 9 for Figure 2 Enlarged view of point D in the middle. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are for illustrative purposes only.

[0034] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0035] In the description of this specification, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0037] See also Figure 1 and Figure 2In some embodiments, the submersible motor protector 1000 includes a housing 1, a transmission shaft 2, a first capsule assembly 3, a first one-way valve 4, and a second capsule assembly 5. The transmission shaft 2 is inserted into the housing 1. The first capsule assembly 3 includes a first capsule 31, which is arranged in the housing 1 and sleeved on the transmission shaft 2, and a first chamber a is provided between the first capsule 31 and the transmission shaft 2. The first one-way valve 4 is connected to the first chamber a. The second capsule assembly 5 includes a second capsule 51, a serpentine pipe 53, and a second one-way valve 52, the second capsule 51 is arranged in the housing 1 and sleeved on the transmission shaft 2, and a second chamber b is provided between the second capsule 51 and the transmission shaft 2, the second chamber b is connected to the first one-way valve 4, one end of the serpentine pipe 53 is connected to the second chamber b, and the other end of the serpentine pipe 53 is connected to the second one-way valve 52. Among them, the first one-way valve 4 is used to allow the fluid in the first chamber a to flow to the second chamber b, and the second one-way valve 52 is used to discharge the fluid in the serpentine pipe 53. The serpentine pipe 53 extends the path for the well fluid to enter the second chamber b and can retain part of the well fluid. When the well fluid flows back through the second one-way valve 52, it first flows through the serpentine pipe 53 and then finally enters the second chamber b. When the first one-way valve 4 and the second one-way valve 52 are opened and the first chamber a discharges the lubricating fluid to the outside through the second one-way valve 52, the well fluid retained in the serpentine pipe 53 can be discharged together.

[0038] The submersible motor protector 1000 provided in the embodiment of the present application is beneficial to delaying the time for the well fluid to enter the first chamber a by setting the second chamber b in the flow path between the first chamber a and the second one-way valve 52, and further setting a serpentine pipe 53 in the second chamber b, which further delays the time for the well fluid to finally enter the first chamber a, thereby improving the service life of the submersible screw pump.

[0039] In some embodiments, along the direction X from the second chamber b to the first chamber a, the first chamber a has a top end a1 and a bottom end a2 that are relatively arranged, and the first one-way valve 4 is connected to the top end a1 of the first chamber a, and the top end a1 is also used to communicate with the lubrication channel of the high-pressure bearing assembly. When the submersible motor protector 1000 is working underground, the direction X from the second chamber b to the first chamber a is the same as the direction of gravity, and impurities such as water with a higher density in the well fluid entering the first chamber a are deposited at the bottom end a2 of the first chamber a under the action of gravity. The first chamber a is connected to the lubrication channel 321 of the high-pressure bearing assembly through the top end a1, so when the lubricating fluid is transported to the high-pressure bearing assembly, the lubricating fluid located at the top end a1 suspended in the first chamber a can be provided preferentially, which is conducive to reducing the problem of impurities such as water with a higher density in the well fluid entering the high-pressure bearing assembly and causing damage to it.

[0040] See also Figure 2 and Figure 3In some embodiments, the serpentine pipe 53 includes a serpentine pipe unit 531, and the serpentine pipe unit 531 includes a first straight segment 5311, a bent segment 5312, and a second straight segment 5313. The first straight segment 5311 and the second straight segment 5313 extend along the axial direction of the transmission shaft 2, respectively, and the first straight segment 5311 and the second straight segment 5313 are arranged at intervals along the radial direction of the transmission shaft 2. One end of the first straight segment 5311 facing the first capsule 31 is connected to one end of the bent segment 5312, and one end of the second straight segment 5313 facing the first capsule 31 is connected to the other end of the bent segment 5312. The other end of the first straight segment 5311 is connected to the second chamber b, and the other end of the second straight segment 5313 is connected to the second one-way valve 52.

[0041] When the submersible motor protector 1000 is working underground, the axial direction of the transmission shaft 2 is parallel to the direction of gravity, and the first straight segment 5311 and the second straight segment 5313 are both extended along the axial direction of the transmission shaft 2, which is conducive to allowing impurities such as water in the well fluid with a density greater than that of the lubricating fluid to be deposited in the bent segment 5312 at the bottom through the first straight segment 5311 and the second straight segment 5313 under the action of gravity. The bent segment 5312 is conducive to reducing the flow rate of the liquid in the serpentine, so that the well fluid has more opportunities to remain in the serpentine pipe 53, thereby delaying the time when the well fluid finally enters the first chamber a.

[0042] In this embodiment, the first straight segment 5311 and the second straight segment 5313 are both straight tubes, and the bent segment 5312 is a U-shaped tube. It can be understood that in some other embodiments, the shapes of the first straight segment, the second straight segment and the bent segment can be set according to actual needs, for example, the first straight segment and the second straight segment can also be set to a curved tube, and the bent segment can also be set to a straight tube, which is not limited here.

[0043] See also Figure 3 , Figure 4 and Figure 5 In some embodiments, the serpentine pipe 53 includes at least two serpentine pipe units 531 and at least one connecting section 532, each connecting section 532 being connected between two corresponding adjacent serpentine pipe units 531. One end of the connecting section 532 is connected to the first straight line segment 5311 of a corresponding serpentine pipe unit 531, and the other end of the connecting section 532 is connected to the second straight line segment 5313 of another corresponding serpentine pipe unit 531, so that two adjacent serpentine pipe units 531 are connected. Among them, the connecting section 532 is a U-shaped tube. It can be understood that in some other embodiments, the shape of the connecting section 532 can be set according to actual needs, such as being set to a straight tube, which is not limited here.

[0044] In some embodiments, the serpentine tube unit 531 at the head end is communicated with the second chamber b, and the serpentine tube unit 531 at the tail end is communicated with the second one-way valve 52. Specifically, in the serpentine tube unit 531 at the head end, the end of the first straight section 5311 away from the bent section 5312 is provided with a first opening 5311a, and the first opening 5311a is communicated with the second chamber b; in the serpentine tube unit 531 at the tail end, the end of the second straight section 5313 away from the bent section 5312 is provided with a second opening 5313a, and the second opening 5313a is communicated with the second one-way valve 52.

[0045] In some embodiments, the serpentine pipe 53 is disposed around the outer circumference of the transmission shaft 2. Specifically, at least two serpentine pipe units 531 are disposed along the circumference of the transmission shaft 2 at intervals.

[0046] See also Figure 2 , Figure 6 and Figure 7 In some embodiments, the submersible motor protector 1000 includes a first internal joint 6, which is disposed in the shell 1 and sleeved on the transmission shaft 2, the first internal joint 6 is connected between the first capsule assembly 3 and the second capsule assembly 5, and the first one-way valve 4 is installed on the first internal joint 6.

[0047] In some embodiments, the first inner joint 6 is provided with a first mounting hole 61, and the transmission shaft 2 is passed through the first mounting hole 61. In particular, along the axial direction of the transmission shaft 2, the first mounting hole 61 passes through the first inner joint 6, and the first mounting hole 61 and the transmission shaft 2 are coaxially arranged.

[0048] In some embodiments, the first inner joint 6 is provided with a first connecting hole 62, the first one-way valve 4 is provided in the first connecting hole 62, and the two ends of the first connecting hole 62 are respectively connected to the first capsule 31 and the second capsule 51. In the axial direction of the transmission shaft 2, the first connecting hole 62 passes through the first inner joint 6, and the first connecting hole 62 is provided on the outer side of the first mounting hole 61 in the radial direction.

[0049] See also Figure 2 , Figure 7 and Figure 8 In some embodiments, the second capsule assembly 5 further includes a second inner joint 7, which is disposed in the shell 1 and sleeved on the transmission shaft 2, and the second inner joint 7 is connected to an end of the second capsule 51 that is away from the first capsule 31.

[0050] In some embodiments, the second inner joint 7 is provided with a second mounting hole 71, and the transmission shaft 2 is passed through the second mounting hole 71. In particular, along the axial direction of the transmission shaft 2, the second mounting hole 71 passes through the second inner joint 7, and the second mounting hole 71 is coaxially arranged with the transmission shaft 2.

[0051] In some embodiments, the second inner joint 7 is provided with a second connecting hole 72, the second one-way valve 52 is disposed in the second connecting hole 72, and the serpentine pipe 53 is connected with one end of the second connecting hole 72 facing the second capsule 51. In the axial direction of the transmission shaft 2, the second connecting hole 72 penetrates the second inner joint 7, and the second connecting hole 72 is disposed on the outer side of the second mounting hole 71 in the radial direction.

[0052] See also Figure 2 , Figure 3 and Figure 7 In some embodiments, the second capsule 51 is generally in the shape of a tube with openings at both ends. Along the direction X from the second chamber b to the first chamber a, the first internal joint 6 and the second internal joint 7 are respectively arranged at the openings at both ends of the second capsule 51. The first internal joint 6, the second capsule 51, the second internal joint 7 and the outer wall of the transmission shaft 2 together enclose the second chamber b.

[0053] In some embodiments, the number of the second capsule assemblies 5 is at least two, and at least two second capsule assemblies 5 are sequentially arranged along the axial direction of the transmission shaft 2. Every two adjacent second capsule assemblies 5 are connected to each other, and one of the second capsule assemblies 5 is connected to the first one-way valve 4. Among every two adjacent second capsule assemblies 5, the second communication hole 72 of one second capsule assembly 5 close to the first capsule 31 is connected to the second capsule 51 of the other second capsule assembly 5.

[0054] In some embodiments, along the direction X from the second chamber b to the first chamber a, the second inner joint 7 and the second capsule 51 are alternately sleeved on the transmission shaft 2 in sequence, and two adjacent second inner joints 7 are respectively arranged at two opposite openings of the second capsule 51 located between the two, and the two adjacent second inner joints 7 and the second capsule 51 located between the two are enclosed together with the outer wall of the transmission shaft 2 to form a second chamber b. Along the direction X from the second chamber b to the first chamber a, the second inner joint 7 and the first inner joint 6 at the end are respectively arranged at the openings at both ends of the second capsule 51 located at the end, and the second inner joint 7 at the end, the second capsule 51 at the end, the first inner joint 6 and the outer wall of the transmission shaft 2 are enclosed together to form a second chamber b.

[0055] In some embodiments, the second capsule assembly 5 further includes a support sleeve 54, which is disposed in the second cavity and sleeved outside the transmission shaft 2, and a first end of the support sleeve 54 is connected to the second inner joint 7. In each of two adjacent second capsule assemblies 5, a second end of the support sleeve 54 of a second capsule assembly 5 away from the first capsule 31 is connected to the second inner joint 7 of the other second capsule assembly 5.

[0056] In some embodiments, in each two adjacent second capsule assemblies 5 , the first end of the support sleeve 54 of a second capsule assembly 5 away from the first capsule 31 is inserted into the second mounting hole 71 of the second capsule assembly 5 , and the second end of the support sleeve 54 is inserted into the second mounting hole 71 of the other second capsule assembly 5 .

[0057] In some embodiments, the support sleeve 54 is provided with a liquid passage hole 541, and the liquid passage hole 541 is used for the lubricating liquid to flow through. There are multiple liquid passage holes 541, and the multiple liquid passage holes 541 are arranged in an array.

[0058] In some embodiments, in the second capsule assembly 5 adjacent to the first capsule assembly 3 , the second end of the support sleeve 54 is connected to the first inner joint 6 .

[0059] See also Figure 7 and Figure 8 In some embodiments, the submersible motor protector 1000 further includes a rotating bearing 8, which is disposed between the second inner joint 7 and the transmission shaft 2. The rotating bearing 8 is disposed in the second mounting hole 71, and the rotating bearing 8 is sleeved on the transmission shaft 2 to reduce the friction between the second inner joint 7 and the transmission shaft 2. The rotating bearing 8 can be a sliding bearing, a rolling bearing, etc., which is not limited here.

[0060] See also Figure 3 In some embodiments, the submersible motor protector 1000 further includes an anti-rotation connector 9, which is respectively connected to the second inner joint 7 and the housing 1, and is used to circumferentially limit the second inner joint 7 to prevent the second inner joint 7 from rotating with the transmission shaft 2. Along the radial direction of the transmission shaft 2, one end of the anti-rotation connector 9 is inserted into the housing 1, and the other end is inserted into the second inner joint 7.

[0061] See also Figure 3 and Figure 7 In some embodiments, the submersible motor protector 1000 further includes a sealing ring 73, which is connected between the second inner joint 7 and the transmission shaft 2. The sealing ring 73 is used to prevent liquid from flowing through the gap between the inner wall of the second mounting hole 71 and the transmission shaft 2. The sealing ring 73 is disposed in the second mounting hole 71, and the sealing ring 73 is sleeved on the transmission shaft 2.

[0062] See also Figure 1 and Figure 2 In some embodiments, a third chamber c is provided between the housing 1 and the first capsule 31, and the housing 1 is provided with a first through hole 112, which respectively connects the outside of the housing 1 and the third chamber c. The first through hole 112 is used for allowing liquid to flow between the outside of the housing 1 and the third chamber c to maintain pressure balance between the outside of the housing 1 and the inside of the third chamber c.

[0063] In some embodiments, a fourth chamber d is provided between the housing 1 and the second capsule 51, and the housing 1 is further provided with a second through hole 122, which is connected to the outside of the housing 1 and the fourth chamber d respectively. The second through hole 122 is used for allowing liquid to flow between the outside of the housing 1 and the fourth chamber d to maintain pressure balance between the outside of the housing 1 and the inside of the fourth chamber d.

[0064] In some embodiments, the submersible motor protector 1000 further includes a two-way valve 1221, which is installed in the second through hole 122. The two-way valve 1221 is a two-way pressure valve, and when the pressure in the fourth chamber d is greater than the pressure outside the shell 1, the two-way valve 1221 can discharge the liquid in the fourth chamber d to the outside of the shell 1; when the pressure outside the shell 1 is greater than the pressure in the fourth chamber d, the two-way valve 1221 can allow the liquid outside the shell 1 to enter the fourth chamber d.

[0065] In some embodiments, the housing 1 includes a first housing 11, a second housing 13, and a first adapter 12, wherein two ends of the first adapter 12 are connected to the first housing 11 and the second housing 13, respectively. The first capsule 31 is disposed in the first housing 11, and one end of the first capsule 31 facing the second capsule 51 is connected to the first adapter 12. The second capsule 51 is disposed in the second housing 13, and one end of the second capsule 51 facing the first capsule 31 is connected to the first adapter 12. The inner wall of the first housing 11, the outer wall of the first capsule 31, and one end of the first adapter 12 facing away from the second housing 13 jointly define a third chamber c. The inner wall of the second housing 13, the outer wall of the second capsule 51, the outer wall of the first inner joint 6, the outer wall of the second inner joint 7, and one end of the first adapter 12 facing the second housing 13 jointly define a fourth chamber d. Among them, the second through hole 122 is disposed in the first adapter 12.

[0066] In some embodiments, a second adapter 111 is provided at one end of the first housing 11 away from the second housing 13, and a third adapter 131 is provided at one end of the second housing 13 away from the first housing 11. Along the axial direction of the transmission shaft 2, the two ends of the transmission shaft 2 are respectively penetrated by the second adapter 111 and the third adapter 131. The second adapter 111 is used to connect with the high thrust bearing assembly, and the third adapter 131 is used to connect with the pump body of the submersible screw pump.

[0067] See also Figure 2 , Figure 6 and Fig. 9 In some embodiments, the first adapter 12 is sleeved on the transmission shaft 2, and a liquid passage 121 is provided between the first adapter 12 and the transmission shaft 2, and both ends of the liquid passage 121 are respectively connected to the first chamber a and the first one-way valve 4.

[0068] In some embodiments, the first adapter 12 is provided with a third mounting hole (not shown), the transmission shaft 2 is passed through the third mounting hole, the outer peripheral wall of the transmission shaft 2 and the inner wall of the third mounting hole are enclosed to form a liquid passage 121, and the end of the first internal joint 6 away from the second capsule 51 is inserted into the third mounting hole, and the end of the first connecting hole 62 away from the second chamber b is connected to the first end of the liquid passage 121.

[0069] In some embodiments, the first capsule assembly 3 further includes a protective tube 32, one end of which is connected to the first adapter 12, the first capsule 31 is sleeved outside the protective tube 32, and the first capsule 31 and the protective tube 32 enclose a first chamber a. The protective tube 32 is sleeved outside the transmission shaft 2, and a lubrication channel 321 is provided between the protective tube 32 and the transmission shaft 2, and the lubrication channel 321 is connected to the first chamber a and the liquid passage 121 respectively.

[0070] In some embodiments, the first capsule assembly 3 also includes a separation sealing ring 33, which is arranged in the lubrication channel 321. The separation sealing ring 33 separates the lubrication channel 321 along the axial direction of the transmission shaft 2 to form a first part 321a and a second part 321b. The first part 321a is connected to the second end of the liquid passage 121.

[0071] In some embodiments, the protective tube 32 is provided with a third through hole 322 at a position aligned with the first portion 321a in the radial direction, and the third through hole 322 connects the first portion 321a with the top a1 of the first chamber a. The protective tube 32 is provided with a fourth through hole 323 at a position aligned with the second portion 321b in the radial direction, and the fourth through hole 323 connects the second portion 321b with the top a1 of the first chamber a. When the first one-way valve 4 is opened, the lubricating fluid in the first chamber a passes through the third through hole 322, the first portion 321a, the liquid passage 121, and the first one-way valve 4 and enters the second chamber b; when the lubricating fluid pressure in the high-pressure bearing assembly decreases, the lubricating fluid in the first chamber a passes through the fourth through hole 323 and the second portion 321b and flows to the high-pressure bearing assembly.

[0072] See also Figure 2 and Figure 8 In some embodiments, along the axial direction of the transmission shaft 2, the second one-way valve 52 (such as Figure 5The one-way valve 52 in the fourth chamber d is connected to the end of the fourth chamber d away from the first chamber a, and the end of the fourth chamber d close to the first chamber a is connected to the second through hole 122. By setting the second one-way valve 52 of the second capsule assembly 5 away from the first capsule assembly 3 to be connected to the end of the fourth chamber d away from the first chamber a, and the second through hole 122 to be connected to the end of the fourth chamber d close to the first chamber a, when the submersible motor protector 1000 is working underground, under the action of gravity, impurities with a density greater than that of the lubricating fluid, such as water in the well fluid, which enters the fourth chamber d through the second through hole 122, will accumulate at the end of the fourth chamber d close to the first chamber a, thereby facilitating the delay of the time for impurities with a density greater than that of the lubricating fluid, such as water in the well fluid, to enter the second chamber b through the second one-way valve 52 of the second capsule assembly 5 away from the first capsule assembly 3.

[0073] In some embodiments, the submersible motor protector 1000 further includes a high thrust bearing assembly and a lower protector, the third adapter 131 is connected to the pump body of the submersible screw pump, the second adapter 111 is connected to the high thrust bearing assembly, the lower protector is connected to the high thrust bearing assembly, and the other end of the lower protector is used to connect to the motor of the submersible screw pump. The submersible motor protector 1000 is used to provide an appropriate amount of lubricating fluid to the high thrust bearing assembly to prevent well fluid from entering the high thrust bearing assembly; the lower protector is used to prevent well fluid from entering the motor, and can provide the motor with the required lubricating fluid to play a cooling and lubricating role; the high thrust bearing assembly is used to bear the downward axial force from the pump body to prevent the axial force from directly acting on the motor and causing damage to the motor. When the pump body is abnormally reversed, the high thrust bearing assembly is used to bear the upward axial pulling force of the pump body.

[0074] In order to facilitate readers to understand the present invention, the working principle of a submersible motor protector 1000 provided in this application is fully described below:

[0075] When the submersible screw pump is working, when the internal temperature of the high thrust bearing assembly increases, the lubricating fluid in the high thrust bearing assembly expands, and the lubricating fluid overflowing from the lubrication channel of the high thrust bearing assembly enters the first chamber a. The pressure in the first chamber a increases, causing the first one-way valve 4 to open. The lubricating fluid in the first chamber a passes through the third through hole 322, the first part 321a, the liquid passage 121 and the first one-way valve 4 and enters the second chamber b of the second capsule assembly 5 adjacent to the first chamber a, and then enters the serpentine pipe 53 through the first opening 5311a. After flowing through the entire serpentine pipe 53, it passes through the second one-way valve 52 and enters the second chamber b of another adjacent second capsule assembly 5, and is finally discharged from the second one-way valve 52 of the second capsule assembly 5 located away from the first chamber a.

[0076] During the operation of the submersible screw pump, impurities that flow back into the submersible screw pump need to flow through each second capsule assembly 5 before finally entering the first chamber a. In a cycle from the opening to the closing of the second one-way valve 52, impurities that flow back into the submersible screw pump first enter the serpentine pipe 53, and impurities with higher density are deposited in the bent section 5312 under the action of gravity. After the impurities fill and replace the lubricating fluid in the serpentine pipe 53, they can enter the second chamber b through the first opening 5311a of the serpentine pipe 53. When the lubricating fluid in the high-thrust bearing assembly expands next time and the second one-way valve 52 is opened, the impurities accumulated in the serpentine pipe 53 will also flow toward the second one-way valve 52 of the second capsule assembly 5 located far away from the first chamber a under the push of the lubricating fluid, and thus be discharged to the upstream second chamber b or discharged through the second one-way valve 52 of the second capsule assembly 5 located far away from the first chamber a, thereby further delaying the time of entering the first chamber a.

[0077] When the submersible screw pump is shut down normally or has a power outage, the internal temperature of the submersible screw pump decreases, and the lubricating fluid in the first chamber a flows to the lubricating channel of the high thrust bearing assembly to replenish the required lubricating fluid.

[0078] Based on the same inventive concept, the present application also provides a submersible screw pump, including the submersible motor protector 1000 in any of the above embodiments.

[0079] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A submersible motor protector, characterized in that: include: case; A transmission shaft is inserted into the housing; A first capsule assembly, comprising a first capsule, wherein the first capsule is disposed in the housing and sleeved on the transmission shaft, and a first chamber is provided between the first capsule and the transmission shaft; a first one-way valve, connected to the first chamber; a second capsule assembly, comprising a second capsule, a serpentine pipe and a second one-way valve, wherein the second capsule is disposed in the housing and sleeved on the transmission shaft, a second chamber is disposed between the second capsule and the transmission shaft, the second chamber is communicated with the first one-way valve, one end of the serpentine pipe is communicated with the second chamber, and the other end of the serpentine pipe is communicated with the second one-way valve; The first one-way valve is used to allow the fluid in the first chamber to flow to the second chamber, and the second one-way valve is used to allow the fluid in the serpentine pipe to be discharged.

2. The submersible motor protector according to claim 1, characterized in that: The serpentine pipeline includes a serpentine pipe unit, and the serpentine pipe unit includes a first straight segment, a bent segment, and a second straight segment; The first straight line segment and the second straight line segment extend respectively along the axial direction of the transmission shaft, and the first straight line segment and the second straight line segment are arranged at intervals along the radial direction of the transmission shaft; One end of the first straight segment facing the first capsule is connected to one end of the bent segment, and one end of the second straight segment facing the first capsule is connected to the other end of the bent segment; The other end of the first straight line segment is communicated with the second chamber, and the other end of the second straight line segment is communicated with the second one-way valve.

3. The submersible motor protector according to claim 2, characterized in that: The serpentine pipeline comprises at least two serpentine pipe units and at least one connecting section, each of the connecting sections being connected between two corresponding adjacent serpentine pipe units; One end of the connecting segment is connected to the first straight line segment of a corresponding one of the serpentine pipe units, and the other end of the connecting segment is connected to the second straight line segment of another corresponding one of the serpentine pipe units.

4. The submersible motor protector according to claim 1, characterized in that: The submersible motor protector includes a first inner joint, which is arranged in the shell and sleeved on the transmission shaft. The first inner joint is connected between the first capsule assembly and the second capsule assembly, and the first one-way valve is installed on the first inner joint.

5. The submersible motor protector according to claim 1, characterized in that: The second capsule assembly further includes a second inner joint, which is disposed in the shell and sleeved on the transmission shaft, and the second inner joint is connected to an end of the second capsule away from the first capsule.

6. The submersible motor protector according to claim 5, characterized in that: The second inner joint is provided with a second communicating hole, the second one-way valve is arranged in the second communicating hole, and the other end of the serpentine pipeline is communicated with one end of the second communicating hole toward the second capsule.

7. The submersible motor protector according to claim 6, characterized in that: The number of the second capsule assemblies is at least two, and the at least two second capsule assemblies are arranged in sequence along the axial direction of the transmission shaft; In every two adjacent second capsule assemblies, the second communicating hole of one of the second capsule assemblies close to the first capsule is communicated with the second capsule of the other second capsule assembly.

8. The submersible motor protector according to claim 7, characterized in that: The second capsule assembly further includes a support sleeve, which is disposed in the second chamber and sleeved outside the transmission shaft, and one end of the support sleeve is connected to the second inner joint; In every two adjacent second capsule components, the support sleeve of one of the second capsule components away from the first capsule is connected to the second inner joint of the other second capsule component.

9. The submersible motor protector according to any one of claims 5 to 8, characterized in that: It also includes a rotary bearing, which is arranged between the second inner joint and the transmission shaft; and / or It also includes an anti-rotation connection member, wherein the anti-rotation connection member is respectively connected to the second inner joint and the housing; and / or It also includes a sealing ring, which is connected between the second inner joint and the transmission shaft.

10. The submersible motor protector according to claim 1, characterized in that: The number of the second capsule assemblies is at least two, and the at least two second capsule assemblies are arranged in sequence along the axial direction of the transmission shaft; Every two adjacent second capsule assemblies are communicated with each other, and one of the second capsule assemblies is communicated with the first one-way valve.

11. The submersible motor protector according to claim 1, characterized in that: A third chamber is provided between the shell and the first capsule, and the shell is provided with a first through hole, the first through hole being connected to the outside of the shell and the third chamber respectively; and / or A fourth chamber is provided between the shell and the second capsule, and the shell is further provided with a second through hole, wherein the second through hole is connected to the outside of the shell and the fourth chamber respectively.

12. The submersible motor protector according to claim 1, characterized in that: A fourth chamber is provided between the shell and the second capsule, and the shell is provided with a second through hole, and the second through hole is connected to the outside of the shell and the fourth chamber respectively; The submersible motor protector further includes a two-way valve, and the two-way valve is installed in the second through hole.

13. The submersible motor protector according to claim 1, characterized in that: The housing comprises a first housing, a second housing and a first adapter, wherein two ends of the first adapter are respectively connected to the first housing and the second housing; The first capsule is disposed in the first shell, and one end of the first capsule facing the second capsule is connected to the first adapter; The second capsule is disposed in the second shell, and one end of the second capsule facing the first capsule is connected to the first adapter.

14. The submersible motor protector according to claim 13, characterized in that: The first adapter is sleeved on the transmission shaft, a liquid passage is provided between the first adapter and the transmission shaft, and two ends of the liquid passage are respectively communicated with the first chamber and the first one-way valve.

15. The submersible motor protector according to claim 14, characterized in that: The first capsule assembly further includes a protective tube, one end of which is connected to the first adapter, the first capsule is sleeved outside the protective tube, and the first capsule and the protective tube are enclosed to form the first chamber; The protective tube is sleeved outside the transmission shaft, and a lubrication channel is provided between the protective tube and the transmission shaft, and the lubrication channel is respectively connected to the first chamber and the liquid passage.

16. A submersible screw pump, characterized in that: It comprises a submersible motor protector as described in any one of claims 1 to 15.

Images