A cable sealing device for permanent magnet synchronous motor

Abstract

The present invention relates to the technical field of oil production equipment, and discloses a cable sealing device for a permanent magnet synchronous motor, including a motor outlet seat, characterized in that it also includes a hollow first sealing joint, a sealing cushion located in the first sealing joint, a first pressure cap threadedly connected to the outer wall of the first sealing joint, a hollow second sealing joint, a sealing member located in the second sealing joint, and a pressure head threadedly connected in the second sealing joint and pressed against the sealing member. The present invention has the following advantages and effects: The present invention solves the sealing problem between the outlet cable of the permanent magnet synchronous motor and the motor by setting a multi-layer sealing structure, and the sealing is reliable, and at the same time, it is resistant to high temperature, high pressure and corrosion; the outlet cable of the motor is convenient to connect with the external cable, and the connection point is firm and reliable, which greatly enhances the performance of the motor and prolongs the service life of the motor.

Description

Technical Field

[0001] The invention relates to the technical field of oil production equipment, and in particular to a cable sealing device for a permanent magnet synchronous motor. Background Art

[0002] The submersible direct-drive permanent magnet synchronous motor is the power source of the submersible screw pump system. It needs to work at a depth of several thousand meters in the oil well and is affected by the downhole pressure, temperature, and corrosion problems. The sealing problem of the motor output cable is particularly serious.

[0003] In the prior art, Chinese patent with authorization announcement number CN2817188Y discloses an integrated submersible motor with a sealing device, and Chinese patent with authorization announcement number CN201142608Y discloses a submersible linear motor sealing device. These patents are all aimed at the sealing structure of the submersible motor itself and do not involve the sealing of the outgoing cable.

[0004] A Chinese patent with authorization announcement number CN105186439B discloses a cable joint sealing structure for a high-temperature submersible electric pump, including a shell and a fluoroplastic straight protective tube, characterized in that an oil injection capillary is arranged in the middle of the shell, and the oil injection capillary is connected to the inside of the shell; inside the shell on both sides of the oil injection capillary, T-shaped protective tubes, corrugated tube-shaped sealing sleeves, washers and fluoroplastic straight protective tubes are arranged in sequence from inside to outside; pressure regulating screw sleeves are respectively arranged at both ends of the shell, the inner side of the pressure regulating screw sleeves is in contact with the fluoroplastic straight protective tube, and the outer side is threadedly connected to the inner side of the shell; a spring is arranged inside the shell between the washer and the pressure regulating screw sleeve.

[0005] A Chinese patent with authorization announcement number CN206962616U discloses a static sealing structure for cable lead-out wires of a submersible permanent magnet motor, comprising a motor stator outer cylinder and a cable lead-out wire installed inside the motor stator outer cylinder; a lead-out wire locking nut and a lead-out wire pressing nut are sequentially installed on the cable lead-out wire; a portion of the cable lead-out wire located inside the motor stator outer cylinder is installed with a primary lead-out wire sealing ring, and a portion of the cable lead-out wire located inside the lead-out wire locking nut is installed with a secondary lead-out wire sealing coil; a front end of the lead-out wire locking nut is threadedly connected to a front end of the motor stator outer cylinder, and a front end of the lead-out wire pressing nut is threadedly connected to a rear end of the lead-out wire locking nut.

[0006] During the research and development of small-diameter and small-size submersible permanent magnet synchronous motors, the applicant has developed a submersible permanent magnet synchronous motor with an outer diameter of 66 mm. Currently, there is no sealing structure specifically for the outlet of such small-diameter submersible motors in the prior art. For example, the Chinese patent with the authorization announcement number CN105186439B mentioned above has a too complex structure and has components such as springs, which cannot be assembled and applied to small-diameter submersible motors. The Chinese patent with the authorization announcement number CN206962616U mentioned above has the following problems: First, the outlet cable of the submersible motor is generally three wires, not one. When the outlet cable is placed in the middle position during sealing, there will be hidden dangers in the insulation between the three wires; second, the sealing of the gap between the outer wall of the cable lead and the inner wall of the press-fit nut has not been solved, and the sealing performance is poor. Summary of the invention

[0007] The object of the present invention is to provide a cable sealing device for a permanent magnet synchronous motor, which has a reliable sealing effect.

[0008] The above technical objectives of the present invention are achieved through the following technical solutions: A cable sealing device for a permanent magnet synchronous motor, comprising a motor outlet seat, and also comprising a hollow first sealing joint, a sealing cushion 1 located in the first sealing joint, a first pressure cap threadedly connected to the outer wall of the first sealing joint, a hollow second sealing joint, a sealing member located in the second sealing joint, and a pressure head threadedly connected to the second sealing joint and pressed against the sealing member; the first sealing joint is threadedly connected to the motor outlet seat, and a first sealing cushion is provided between the first sealing joint and the motor outlet seat; the sealing cushion 1 is provided with a wire outlet hole 1; the second sealing joint is inserted into the first sealing joint and pressed against the sealing cushion 1, an outer step is formed on the outer wall of the second sealing joint, the outer step is pressed against the first sealing joint, a second sealing cushion is provided between the first sealing joint and the second sealing joint, the first pressure cap is formed with a first inner edge, and the first inner edge is buckled on the outer step; the sealing member is provided with a wire outlet hole 2; the pressure head is provided with a through hole.

[0009] By adopting the above technical scheme, the first sealing joint is threadedly connected to the motor outlet seat, pressing the first sealing gasket to seal the first sealing joint and the motor outlet seat; the first gland is threadedly connected to the first sealing joint, and the first gland is rotated, the first gland fastens the outer step on the second sealing joint, and the second sealing joint presses the second sealing gasket to seal the second sealing joint and the first sealing joint, and at the same time, the second sealing joint squeezes and presses the sealing cushion 1, and the sealing cushion 1 is deformed to hold the motor outlet cable tightly, thereby fixing the motor outlet cable and preventing multiple motor outlet cables from being entangled with each other.

[0010] The upper cable passes through the through hole on the pressure head and the second outlet hole on the second sealing cushion. The pressure head presses against the second sealing cushion, and the second sealing cushion holds the upper cable after deformation, thereby fixing the upper cable.

[0011] The present invention is further configured as follows: the first sealing gasket and the second sealing gasket are both metal gaskets.

[0012] By adopting the above technical solution, since the first sealing gasket and the second sealing gasket are easily in contact with the well fluid, metal gaskets made of metal material are selected.

[0013] The present invention is further configured as follows: the sealing cushion 1 is provided with a plurality of the wire outlet holes 1, and the sealing member is provided with a plurality of the wire outlet holes 2.

[0014] By adopting the above technical solution, the number of outlet holes 1 and outlet holes 2 is selected according to the number of motor outlet cables of the submersible permanent magnet synchronous motor. Preferably, the number of outlet holes 1 is three, and the number of outlet holes 2 is three.

[0015] The present invention is further configured as follows: an inner step 1 is formed inside the first sealing joint, one end of the sealing cushion 1 is pressed against the inner step 1, and the other end is pressed against by the second sealing joint.

[0016] The present invention is further configured as follows: a second inner step is formed inside the second sealing joint, the sealing member abuts against the second inner step, and a compartment is formed between the sealing member and the first sealing cushion.

[0017] The present invention is further configured as follows: the sealing element includes a second sealing cushion.

[0018] By adopting the above technical solution, the second gland is tightened, the second gland is buckled with the pressure head, the pressure head squeezes the second sealing cushion, the second sealing cushion is deformed and holds the upper cable, and the position of the upper cable is fixed.

[0019] The present invention is further configured as follows: the sealing member further comprises a first pressing ring and a second pressing ring, and the second sealing cushion is located between the first pressing ring and the second pressing ring.

[0020] The present invention is further configured as follows: the first pressing ring abuts against the second inner step, and a potting glue is provided between the second pressing ring and the pressing head.

[0021] By adopting the above technical solution, the potting glue is used to fill and seal the gaps between the second pressing ring, the second sealing cushion and the upper cable.

[0022] The present invention is further configured as follows: it also includes a sealing ring abutting against the pressure head, and a second pressure cover threadedly connected to the outer wall of the second sealing joint, the second pressure cover is formed with a second inner edge, and the second inner edge is buckled on the sealing ring.

[0023] By adopting the above technical solution, the second gland fastens the sealing ring so that the sealing ring presses against the pressure head, and the position of the pressure head is fixed again, which plays the role of fastening and protecting the upper cable.

[0024] The present invention is further configured as follows: it also includes a motor output cable, an upper cable, and a terminal connection sleeve, the motor output cable terminal and the upper cable terminal are both threadedly connected to the terminal connection sleeve, the motor output cable terminal and the upper cable terminal are conductive after contacting each other, and the terminal connection sleeve is located in the compartment.

[0025] By adopting the above technical solution, the motor outlet cable is installed with a terminal, namely, the motor outlet cable terminal. The upper cable is installed with a terminal, namely, the upper cable terminal. The motor outlet cable passes through the outlet hole 1 of the sealing cushion 1, and is tightly fixed by the deformed sealing cushion 1. The upper cable passes through the outlet hole 2 on the seal, and is tightly fixed by the deformed sealing cushion 2. The two cables are connected by the terminal connection sleeve, and the terminal connection sleeve is located at the position of the compartment to avoid being squeezed and damaged, so that the motor outlet cable is convenient to connect with the external upper cable, and the connection is firm and reliable.

[0026] The beneficial effects of the present invention are:

[0027] 1. The first sealing joint presses the first sealing gasket to seal the gap between the first sealing joint and the motor outlet seat; the second sealing joint is fastened by the first gland, and the second sealing joint presses the second sealing gasket to seal the gap between the first sealing joint and the second sealing joint; the second sealing joint squeezes the sealing cushion 2, and the sealing cushion 1 is deformed and holds the motor outlet cable tightly, which plays a role in sealing and fixing the motor outlet cable; the pressure head squeezes the sealing cushion 2, and the sealing cushion 2 is deformed and holds the upper cable tightly, which plays a role in sealing and fixing the upper cable, and the gap between the pressure ring 2, the sealing cushion 2 and the upper cable is filled and sealed by the potting glue, and the second gland presses the sealing ring and the pressure head, and fixes the position of the pressure head again. A good sealing effect is achieved through multi-layer sealing, and it is simple and convenient during production and assembly.

[0028] 2. The second sealing joint is fixed to the first sealing joint by the first gland. During assembly and disassembly, the first sealing joint and the second sealing joint do not need to rotate relative to each other. The motor outlet cable and the upper cable are easy to align, and multiple motor outlet cables and upper cables will not be entangled with each other.

[0029] 3. The motor outlet cable terminal and the upper cable terminal are both threadedly connected to the cable connection sleeve, and the connection is simple and convenient; the outlet hole 1 on the sealing gasket 1 corresponds one-to-one with the motor outlet cable, and the outlet hole 2 on the sealing gasket 2 corresponds one-to-one with the upper cable. After the sealing gasket 1 is deformed, it fixes the motor outlet cable, and after the sealing gasket 2 is deformed, it fixes the upper cable, thereby ensuring the insulation between multiple motor outlet cables and multiple upper cables.

[0030] 4. Between the first sealing joint and the second sealing joint, the second sealing gasket forms a first layer of sealing, and the second sealing joint is pressed against the sealing cushion to form a second layer of sealing. The sealing member seals the gap between the upper cable and the inside of the second sealing joint, and the potting glue is used to fill the seal to ensure good sealing in the compartment. The terminal connection sleeve is located in the compartment, which can provide a good seal while avoiding extrusion and preventing well fluid from contacting the terminal connection sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 It is a schematic structural diagram of an embodiment.

[0033] Figure 2 It is a schematic diagram of the connection relationship between the motor outlet cable, the upper cable, and the terminal connection sleeve of the embodiment.

[0034] In the figure, 1, motor outlet seat; 2, first sealing joint; 21, inner step one; 3, second sealing joint; 31, inner step two; 32, outer step; 4, first pressure cover; 41, first inner edge; 5, second pressure cover; 51, second inner edge; 6, sealing gasket one; 7, sealing element; 71, pressure ring one; 72, pressure ring two; 73, sealing gasket two; 8, potting glue; 9, sealing ring; 10, pressure head; 11, first sealing gasket; 12, second sealing gasket; 13, compartment; 14, motor outlet cable; 15, upper cable; 16, terminal connection sleeve. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Embodiment: A cable sealing device for a permanent magnet synchronous motor, such as Figure 1 As shown, it includes a motor outlet seat 1, three motor outlet cables 14, three upper cables 15, a hollow first sealing joint 2, a sealing cushion 6 located in the first sealing joint 2, a first pressure cover 4 threadedly connected to the outer wall of the first sealing joint 2, a hollow second sealing joint 3, a sealing member 7 located in the second sealing joint 3, a pressure head 10 threadedly connected to the inner wall of the second sealing joint 3, and a second pressure cover 5 threadedly connected to the second sealing joint 3.

[0037] like Figure 1 As shown, the first sealing joint 2 is threadedly connected to the motor outlet seat 1, and a first sealing gasket 11 is provided between the first sealing joint 2 and the motor outlet seat 1. The first sealing gasket 11 is a metal gasket. An inner step 21 is formed inside the first sealing joint 2, and one end of the sealing gasket 6 is pressed against the inner step 21, and the other end is pressed against the second sealing joint 3. Three outlet holes 1 are provided on the sealing gasket 6, and three motor outlet cables 14 pass through the three outlet holes 1 respectively.

[0038] like Figure 1 As shown, the outer wall of the second sealing joint 3 is integrally formed with an outer step 32, one end of the second sealing joint 3 is inserted into the first sealing joint 2 and abuts against the sealing cushion 6, and a second sealing cushion 12 is arranged between the outer step 32 on the second sealing joint 3 and the end surface of the first sealing joint 2, and the second sealing cushion 12 is a metal cushion. The second sealing cushion 12 plays a sealing role. The first gland 4 is formed with a first inner edge 41, and the first inner edge 41 is buckled on the outer step 32 of the second sealing structure.

[0039] like Figure 1 As shown, the second sealing joint 3 is formed with an inner step 2 31, and the sealing member 7 inside the second sealing joint 3 includes a pressure ring 1 71, a pressure ring 2 72, and a sealing cushion 2 73. The pressure ring 1 71 is pressed against the inner step 2 31, and a compartment 13 is formed between the pressure ring 1 71 and the sealing cushion 1 6. Three outlet holes 2 are provided on the pressure ring 1 71, the pressure ring 2 72, and the sealing cushion 2 73. The space between the pressure head 10 and the pressure ring 2 72 is filled with potting glue 8, and the pressure head 10 is also provided with three through holes for the upper cable 15 to pass through. The second gland 5 on the second sealing joint 3 is formed with a second inner edge 51, and a sealing ring 9 is placed on the pressure head 10. The second inner edge 51 of the second gland 5 is buckled on the sealing ring 9, so that the sealing ring 9 is pressed tightly against the pressure head 10.

[0040] like Figure 2As shown, a terminal connection sleeve 16 is provided between the motor outlet cable 14 and the upper cable 15, and the motor outlet cable 14 is provided with a terminal, namely, a motor outlet cable terminal 141. The upper cable 15 is provided with a terminal, namely, an upper cable terminal 151. The motor outlet cable terminal 141 and the upper cable terminal 151 are both threadedly connected to the terminal connection sleeve 16, and the motor outlet cable terminal 141 and the upper cable terminal 151 are conductive after contacting each other.

[0041] Working principle: The motor outlet cable 14 extends out from the motor outlet seat 1. After the three motor outlet cables 14 are passed through the outlet holes 1 on the sealing gasket 1 6 one by one, the first sealing joint 2 is threadedly connected to the motor outlet seat 1. The first sealing joint 2 presses the first sealing gasket 11, and the first sealing gasket 11 seals the gap between the first sealing joint 2 and the motor outlet seat 1. The second gland 5, the sealing ring 9, the pressure head 10, the pressure ring 1 71, the sealing gasket 2 73, the pressure ring 2 72, and the second sealing joint 3 are passed through the upper cable 15 in sequence. The pressure ring 2 72, the sealing gasket 2 73, the pressure ring 1 71, and the pressure head 10 are installed in the second sealing joint 3. Take three terminal connection sleeves 16, and respectively thread the motor outlet cable 14 terminals and the upper cable 15 terminals on the terminal connection sleeves 16 so that they are in contact and conductive. Take the second sealing gasket 12 and place it between the outer step 32 of the second sealing joint 3 and the end face of the first sealing joint 2, insert one end of the second sealing joint 3 into the first sealing joint 2, tighten the first pressure cover 4, and press the first pressure cover 4 downward to drive the second sealing joint 3 to move. The end of the second sealing joint 3 presses against and squeezes the sealing gasket 6. After the sealing gasket 6 is deformed, it holds the three motor output cables 14 tightly. At the same time, the outer step 32 on the second sealing joint 3 also squeezes the second sealing gasket 12. The second sealing gasket 12 is deformed and seals the gap between the first sealing joint 2 and the second sealing structure. At this time, the terminal connection sleeve 16 is located in the compartment 13.

[0042] Inject the potting glue 8 into the second sealing joint 3 to fill and seal the gap between the pressure ring 2 72, the sealing cushion 2 73 and the cable. After the potting glue 8 is injected into the second sealing joint 3, tighten the pressure head 10 immediately. The pressure head 10 squeezes the pressure ring 2 72 and the sealing cushion 2 73. After the potting glue 8 is solidified, the sealing cushion 2 73 is deformed and holds the upper cable 15 tightly. The sealing performance is strong, preventing the well fluid from entering the motor along the upper cable 15 and the motor outlet cable 14. Then tighten the second gland 5, and the second gland 5 buckles the sealing ring 9, so that the sealing ring 9 rests on the pressure head 10, and the position of the pressure head 10 is fixed again.

Claims

1. A cable sealing device for a permanent magnet synchronous motor, comprising a motor outlet seat (1), characterized in that: The invention also comprises a hollow first sealing joint (2), a sealing cushion (6) located in the first sealing joint (2), a first gland (4) threadedly connected to the outer wall of the first sealing joint (2), a hollow second sealing joint (3), a sealing member (7) located in the second sealing joint (3), and a pressing head (10) threadedly connected to the second sealing joint (3) and pressed against the sealing member (7); the first sealing joint (2) is threadedly connected to the motor outlet seat (1), and a first sealing cushion (11) is provided between the first sealing joint (2) and the motor outlet seat (1); the sealing cushion (6) is threadedly connected to the outer wall of the first sealing joint (2), and the sealing member (7) is threadedly connected to the motor outlet seat (1). (6) is provided with a wire outlet hole 1; the second sealing joint (3) is inserted into the first sealing joint (2) and then pressed against the sealing cushion 1 (6); the outer wall of the second sealing joint (3) is formed with an outer step (32), the outer step (32) presses against the first sealing joint (2), a second sealing cushion (12) is provided between the first sealing joint (2) and the second sealing joint (3); the first pressure cover (4) is formed with a first inner edge (41), the first inner edge (41) is buckled on the outer step (32); the sealing member (7) is provided with a wire outlet hole 2; the pressure head (10) is provided with a through hole.

2. A cable sealing device for a permanent magnet synchronous motor according to claim 1, characterized in that: The first sealing gasket (11) and the second sealing gasket (12) are both metal gaskets.

3. A cable sealing device for a permanent magnet synchronous motor according to claim 1, characterized in that: The sealing cushion 1 (6) is provided with a plurality of the wire outlet holes 1, and the sealing member (7) is provided with a plurality of the wire outlet holes 2.

4. The cable sealing device for a permanent magnet synchronous motor according to claim 1, characterized in that: An inner step 1 (21) is formed inside the first sealing joint (2), one end of the sealing cushion 1 (6) is pressed against the inner step 1 (21), and the other end is pressed against the second sealing joint (3).

5. The cable sealing device for a permanent magnet synchronous motor according to claim 1, characterized in that: The second sealing joint (3) is internally formed with an inner step 2 (31), the sealing member (7) abuts against the inner step 2 (31), and a compartment (13) is formed between the sealing member (7) and the sealing cushion 1 (6).

6. A cable sealing device for a permanent magnet synchronous motor according to claim 5, characterized in that: The sealing element (7) comprises a second sealing cushion (73).

7. A cable sealing device for a permanent magnet synchronous motor according to claim 6, characterized in that: The sealing member (7) further comprises a first pressing ring (71) and a second pressing ring (72), and the second sealing cushion (73) is located between the first pressing ring (71) and the second pressing ring (72).

8. A cable sealing device for a permanent magnet synchronous motor according to claim 7, characterized in that: The first pressing ring (71) abuts against the second inner step (31), and a potting glue (8) is provided between the second pressing ring (72) and the pressing head (10).

9. The cable sealing device for a permanent magnet synchronous motor according to claim 1, characterized in that: It also comprises a sealing ring (9) abutting against the pressure head (10), and a second gland (5) threadedly connected to the outer wall of the second sealing joint (3); the second gland (5) is formed with a second inner edge (51), and the second inner edge (51) is buckled on the sealing ring (9).

10. The cable sealing device for a permanent magnet synchronous motor according to claim 5, characterized in that: It also includes a motor outlet cable (14), an upper cable (15), and a terminal connection sleeve (16); the motor outlet cable (14) is installed with a terminal, namely, a motor outlet cable terminal (141); the upper cable (15) is installed with a terminal, namely, an upper cable terminal (151); the motor outlet cable terminal (141) and the upper cable terminal (151) are both threadedly connected to the terminal connection sleeve (16); the motor outlet cable terminal (141) and the upper cable terminal (151) are electrically conductive when in contact with each other; and the terminal connection sleeve (16) is located in the compartment (13).

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