JP6580453B2 - underwater pump - Google Patents

Description

  The present invention relates to a submersible pump.

  Patent Document 1 discloses a submersible pump that is used in seawater. In this submersible pump, a water-resistant motor is disposed at the end of the pump casing. The motor shaft of the water resistant motor protrudes from the inside of the motor casing to the inside of the pump casing. An impeller is fixed to a portion of the motor shaft located inside the pump casing. There is also a submersible pump in which a pump shaft is rotatably arranged inside a pump casing and the pump shaft and a motor shaft are connected by a coupling.

  The water-resistant motor includes a rotor fixed to the outer peripheral portion of the motor shaft and a stator fixed to the motor casing so as to be positioned on the outer peripheral portion of the rotor. A rotating magnetic field is formed by passing an electric current through the electric wire wound around the stator, and an electromotive force is generated in the rotor by the rotating magnetic field, and an electric current flows. And when an electromagnetic force generate | occur | produces between an electric current and a rotating magnetic field, a motor shaft rotates because a rotor rotates inside a stator.

  The motor shaft needs to be formed of a magnetic material (SC material or martensitic stainless material) in order to penetrate the rotating magnetic field generated by the stator. Moreover, since the part arrange | positioned outside the motor casing of a motor shaft is exposed to seawater, it is necessary to form with the nonmagnetic material (stainless steel) excellent in corrosion resistance. Therefore, conventionally, a first motor shaft made of a magnetic material and a second motor shaft made of a nonmagnetic material are formed, and these are integrally connected. Note that the first motor shaft and the second motor shaft cannot be coupled by a coupling component such as a coupling because the inside of the motor casing is narrow. Therefore, the first motor shaft and the second motor shaft are integrally coupled by pressure contact.

JP 2001-41186 A

  However, in the method of connecting the first motor shaft and the second motor shaft by press contact, if there is no track record in the combination of both forming materials, it is necessary to actually test and check the strength. Since this strength check requires a long period (about half a year), the period until the motor shaft is completed becomes long. In addition, since the cost of trial production and the cost of inspection are also required, the manufacturing cost of the motor shaft is increased.

  An object of the present invention is to provide a submersible pump that does not require a prototype for strength confirmation, can shorten the manufacturing period, and can reduce manufacturing costs.

The present invention relates to a pump shaft made of a corrosion-resistant material rotatably disposed in a pump casing, and a magnetic material protruding from the motor casing to the pump casing side so as to be positioned on the same axis as the pump shaft. A mechanical shaft that seals between the motor casing and the motor shaft, and a shaft coupling that integrally connects the pump shaft and the motor shaft. Has a sleeve that covers the outer periphery of the motor shaft from the motor casing to the shaft coupling, and a gap between one end of the shaft coupling and the pump shaft is sealed by a first seal member. , of the seal between the other end and the sleeve of the shaft coupling by the second sealing member And it is, to provide a water pump.

  According to this submersible pump, the portion of the motor shaft that protrudes from the motor casing is covered with the sleeve of the mechanical seal. The shaft coupling and the pump shaft and the shaft coupling and the sleeve are respectively sealed by seal members. Therefore, it is possible to prevent the protruding portion of the motor shaft from being exposed to seawater. Therefore, the motor shaft can be formed of only a magnetic material that can be rotated through the rotor by passing an electric current through the stator. That is, since it is not necessary to integrally connect different forming materials, a prototype for confirming the strength is unnecessary, and the manufacturing period can be shortened and the manufacturing cost can be reduced.

  An insertion portion for inserting the sleeve is provided on the other end side of the shaft coupling, and the second seal member is disposed on an inner peripheral portion of the insertion portion. According to this aspect, it is possible to reliably position the sleeve with respect to the shaft coupling and maintain the state sealed by the second seal member.

  The pump shaft has a key projecting radially outward, and the shaft coupling has a separate coupling holder in which the first seal member is disposed on the one end side. According to this aspect, it is possible to reliably prevent water from entering the shaft coupling while relatively non-rotatably connecting the pump shaft and the shaft coupling.

  The pump shaft has a projecting portion projecting radially outward, and the coupling holder is disposed in contact with the projecting portion. According to this aspect, the shaft coupling can be reliably positioned with respect to the pump shaft.

The shaft coupling is fixed to the pump shaft with a first knock pin through a first insertion hole, and is fixed to the motor shaft with a second knock pin through a second insertion hole. The outer end side of the insertion hole and the second insertion hole is sealed by a third seal member. According to this aspect, it is possible to reliably prevent water from entering the shaft coupling while fixing the motor shaft and the pump shaft to the shaft coupling.

  In the submersible pump of the present invention, since the motor shaft can be prevented from being exposed to seawater, the motor shaft can be formed only of a magnetic material. Therefore, a prototype for strength confirmation is unnecessary, and the manufacturing period can be shortened and the manufacturing cost can be reduced.

Sectional drawing which shows the submersible pump of this embodiment. The partially expanded sectional view of FIG. The exploded perspective view which shows the connection structure of a motor shaft and a pump shaft. Sectional drawing which expanded further the connection part of the pump shaft of FIG. Sectional drawing which expanded the connection part of the motor shaft of FIG. 2 further. Sectional drawing which expanded the spacer disk part of FIG. 2 further.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, terms indicating specific directions and positions (for example, terms including “up”, “down”, “side”, “end”, “top”, “bottom”) are used as necessary. However, the use of these terms is to facilitate understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms.

  FIG. 1 shows a submersible pump 10 according to the present embodiment. This submersible pump 10 is used by being placed in a liquid such as seawater. In the submersible pump 10, a water-resistant motor 20 is disposed on the opposite end (lower side in FIG. 1) of the discharge port 14 of the pump casing 12, and the liquid is drained by the power of the water-resistant motor 20. In the submersible pump 10 of this embodiment, the motor shaft 28 of the water-resistant motor 20 is formed only of a magnetic material having low corrosion resistance, and the portion exposed to the liquid is covered to prevent corrosion of the motor shaft 28.

(Details of pump)
As shown in FIG. 1, a suction port 13 is formed in the pump casing 12 so as to be located at an intermediate portion in FIG. 1. Further, the pump casing is provided with a discharge port 14 on the upper end side in FIG. The suction port 13 and the discharge port 14 are opened in directions orthogonal to each other. The discharge port 14 is connected to a discharge pipe (not shown) that is piped so as to communicate with predetermined equipment.

  A pump shaft 16 is rotatably supported inside the pump casing 12 via a bearing 15. The pump shaft 16 is made of a nonmagnetic material having excellent corrosion resistance, such as stainless steel. An impeller 18 for sucking liquid is connected to the discharge port 14 side of the pump shaft 16 so as not to rotate relatively. Further, the opposite end portion of the pump shaft 16 is a connecting portion 17 connected to the motor shaft 28 and protrudes outward through the pump casing 12.

  A connection casing 19 for disposing the water resistant motor 20 is disposed below the pump casing 12. The connection casing 19 is a hollow frame through which the pump shaft 16 can be inserted, and protrudes downward from the connecting portion 17 of the pump shaft 16.

(Details of water resistant motor)
The water-resistant motor 20 sucks the liquid from the suction port 13 and drains the liquid from the discharge port 14 through the discharge pipe when the impeller 18 rotates through the pump shaft 16 by driving. The water resistant motor 20 includes a hermetically sealed motor casing 22. The motor casing 22 has a cylindrical outer peripheral wall 23, a first lid member 24 that seals the end of the outer peripheral wall 23 on the pump casing 12 side, and an end of the outer peripheral wall 23 opposite to the pump casing 12. And a second lid member 26. The first lid member 24 of the present embodiment includes a connection flange formed integrally with the connection casing 19. A thrust bearing 27 is disposed on the motor casing 22 at the end opposite to the pump casing 12, and a motor shaft 28 is rotatably supported by the thrust bearing 27.

  The motor shaft 28 is integrally formed of one kind of magnetic material (for example, sus420j2) by rolling or the like. On the inner surface side of the outer peripheral wall 23, a stator 31 that forms a rotating magnetic field by passing a current through the wound wire is disposed. The rotor 32 is connected to the outer periphery of the motor shaft 28 so as not to rotate relatively. An electromotive force is generated in the rotor 32 by the rotating magnetic field, and a current flows. An electromagnetic force is generated between the current and the rotating magnetic field, so that the rotor 32 rotates inside the stator 31, and the motor is integrated. The shaft 28 rotates.

  The motor shaft 28 includes a connecting portion 29 connected to the pump shaft 16 at the end opposite to the thrust bearing 27. The connecting portion 29 penetrates the first lid member 24 and protrudes to the pump casing 12 side (inside the connection casing 19) that is outside the motor casing 22. The outer diameter of the connecting portion 29 is smaller than the outer diameter of the main body side on which the rotor 32 is fixed. Thereby, a stepped portion 30 is formed at the boundary portion between the main body and the connecting portion 29. The first lid member 24 is provided with an insertion portion 25 through which the connection portion 29 is inserted. In the motor casing 22, a mechanical seal 35 is disposed on the first lid member 24 in order to prevent (seal) liquid from entering the motor casing 22 from the gap between the motor shaft 28 and the insertion portion 25. . The water resistant motor 20 includes a pressure control device 33 that adjusts the internal pressure of the motor casing 22, and the pressure control device 33 is disposed in the connection casing 19.

  As shown in FIG. 2, the mechanical seal 35 includes a housing 36 disposed in the insertion portion 25 of the first lid member 24 and a sleeve 37 that is fixed so as not to rotate relative to the motor shaft 28. ing. A fixed ring 38 is disposed on the housing 36, and a rotating ring 39 is disposed on the sleeve 37. By rotating the stationary ring 38 and the rotating ring 39 in a pressure contact state, liquid can be prevented from entering between the insertion portion 25 and the motor shaft 28. The sleeve 37 is connected to the pump casing 12 side of the housing 36 with a slinger 40 for preventing foreign matter from entering due to centrifugal force so as not to rotate relative to the knock pin. An oil seal is filled between the slinger 40 and the housing 36.

(Details of pump shaft and motor shaft connection structure)
The pump casing 12 and the motor casing 22 are fixed via the connection casing 19 so that the pump shaft 16 and the motor shaft 28 are located on the same axis. As shown in FIGS. 2 and 3, the pump shaft 16 and the motor shaft 28 are integrally connected by a cylindrical shaft coupling 58. Further, the sleeve 37 of the mechanical seal 35 is extended to the shaft coupling 58 and both ends of the shaft coupling 58 are sealed to prevent the motor shaft 28 from being exposed to liquid.

  The pump shaft 16 includes an annular flange portion 42 (protruding portion) that protrudes radially outward. The pump shaft 16 is provided with a connecting portion 17 having a diameter smaller than that of the flange portion 42 so as to protrude from the flange portion 42. A key attachment portion 43 that is recessed inward in the radial direction and extends in the axial direction is provided on the outer peripheral portion of the connecting portion 17. Although only one key attachment portion 43 of the present embodiment is provided, a pair of key attachment portions 43 may be provided at positions opposed to the radial direction of the pump shaft 16. The key attachment portion 43 is provided with a key 44 having the same shape as viewed from the side. By disposing the key 44 in the key attachment portion 43, the key 44 protrudes radially outward from the outer peripheral surface of the connecting portion 17, and prevents the shaft coupling 58 from rotating in the circumferential direction with respect to the pump shaft 16.

  Further, the connecting portion 17 is provided with a screw hole 45 for attaching the spacer disk 47 to the tip surface facing the motor shaft 28. The spacer disk 47 has a disk shape with a predetermined thickness, and adjusts the arrangement position of the impeller 18 by adjusting the gap amount between the motor shaft 28 and the pump shaft 16. The spacer disk 47 is provided with a screw portion 48 that is screwed into the screw hole 45.

  The connecting portion 29 of the motor shaft 28 is provided with a first key attachment portion 50 that is recessed radially inwardly on the outer peripheral portion and extends in the axial direction. Although only one first key attachment portion 50 is provided as in the case of the pump shaft 16, a pair of first key attachment portions 50 may be provided at positions facing the pump shaft 16 in the radial direction. The first key mounting portion 50 is provided with a first key 51 having the same shape as viewed from the side. By arranging the first key 51 in the first key mounting portion 50, the first key 51 protrudes radially outward from the outer peripheral surface of the connecting portion 29, and the shaft coupling 58 rotates in the circumferential direction with respect to the motor shaft 28. To prevent.

  Further, on the outer peripheral portion of the connecting portion 29, a second key attachment portion 52 is provided on the motor casing 22 side of the first key attachment portion 50 and extends inward in the radial direction and extends in the axial direction. The second key attachment portion 52 has a total axial length smaller than that of the first key attachment portion 50. Although only one second key attachment portion 52 is provided, a pair of second key attachment portions 52 may be provided at positions opposed to the radial direction of the pump shaft 16. The second key attachment portion 52 is provided with a second key 53 having the same shape as viewed from the side. By disposing the second key 53 in the second key attachment portion 52, the second key 53 protrudes radially outward from the outer peripheral surface of the connecting portion 29, and prevents the sleeve 37 from rotating in the circumferential direction with respect to the motor shaft 28. .

  The sleeve 37 of the mechanical seal 35 has a cylindrical shape with a full length extending from the base end (step portion 30) of the coupling portion 29 of the motor shaft 28 in the motor casing 22 to the end portion of the shaft coupling 58. The inner diameter of the sleeve 37 is substantially the same as the outer diameter of the connecting portion 29. The outer diameter of the sleeve 37 is larger than the diameter of a virtual circle having a radius from the axis of the motor shaft 28 to the outer end of the second key 53. The sleeve 37 is provided with a key groove 55 through which the second key 53 can be inserted. Referring to FIG. 2, the key groove 55 is provided so as to extend along the axial direction from one end of the sleeve 37 to the position where the second key 53 is disposed, and to be recessed radially outward from the inner peripheral surface of the sleeve 37.

  The shaft coupling 58 has a full-length cylindrical shape that fits a part of the connecting portion 17 of the pump shaft 16 and the connecting portion 29 of the motor shaft 28. The shaft coupling 58 includes a pump shaft fixing portion 59 that fixes the pump shaft 16 and a motor shaft fixing portion 63 that fixes the motor shaft 28. The pump shaft fixing portion 59 has an inner diameter that is substantially the same as the outer diameter of the pump shaft 16. The motor shaft fixing portion 63 has an inner diameter that is substantially the same as the outer diameter of the motor shaft 28. In this embodiment, the outer diameter of the pump shaft 16 and the outer diameter of the motor shaft 28 are the same, and the inner diameter of the pump shaft fixing portion 59 and the inner diameter of the motor shaft fixing portion 63 are also formed the same. Further, the outer diameter of the shaft coupling 58 is larger than the outer diameter of the pump shaft 16 and larger than the outer diameter of the sleeve 37.

  The pump shaft fixing portion 59 is provided with a first key groove 60 into which the key 44 can be inserted so as to be recessed radially outward from the inner peripheral surface. The motor shaft fixing portion 63 is provided with a second key groove 64 through which the first key 51 can be inserted so as to be recessed radially outward from the inner peripheral surface. The first key groove 60 and the second key groove 64 of the present embodiment are formed with the same inner diameter where the pump shaft fixing portion 59 and the motor shaft fixing portion 63 are continuous, and therefore, from one end side of the shaft coupling 58. It is constituted by a single groove that is continuous over substantially the entire length to the other end side. However, when the protruding amounts of the keys 44 and 51 are different, the depths of the key grooves 60 and 64 are also formed to be different. When the keys 44 and 51 are provided at different positions in the circumferential direction, the key grooves 60 and 64 are also formed at different positions in the circumferential direction.

  The shaft coupling 58 is provided with a holder mounting portion 61 at an end portion (one end side) on the pump shaft 16 side. Further, the shaft coupling 58 is provided with an insertion portion 65 into which the sleeve 37 is inserted into an end portion (the other end side) on the motor shaft 28 side. Further, insertion holes 68A and 68B are provided in the central portion of the shaft coupling 58 with an interval in the axial direction.

  Referring also to FIG. 4, the holder mounting portion 61 is a cylindrical space in which the inner peripheral surface of the end portion of the pump shaft fixing portion 59 is expanded radially outward. The inner diameter of the holder mounting portion 61 is larger than the diameter of a virtual circle having a radius from the axis of the shaft coupling 58 to the outer end of the first key groove 60. A separate coupling holder 75 for liquid-tightly sealing between the shaft coupling 58 and the pump shaft 16 is disposed in the holder mounting portion 61.

  The coupling holder 75 includes an annular insertion portion 76 disposed in the holder mounting portion 61. The insertion portion 76 has an inner diameter that is substantially the same as the outer diameter of the pump shaft 16, and an outer diameter that is substantially the same as the inner diameter of the holder mounting portion 61. An annular seal groove is provided in the inner peripheral portion of the insertion portion 76, and a first O-ring 77A is disposed in the seal groove. Similarly, an annular seal groove is provided on the outer peripheral portion of the insertion portion 76, and a second O-ring 77B is disposed in this seal groove. These O-rings 77A and 77B are first seal members that seal between the shaft coupling 58 and the pump shaft 16.

  The coupling holder 75 includes a flange portion 78 that is disposed in contact with the end surface of the shaft coupling 58. The flange portion 78 is integrally provided continuously with the insertion portion 76 in the axial direction. The inner diameter of the flange portion 78 is substantially the same as the outer diameter of the pump shaft 16, and the outer diameter is substantially the same as the outer diameter of the shaft coupling 58. The flange portion 78 is provided with a screw hole 79 penetrating in the radial direction. Four screw holes 79 are provided at intervals in the circumferential direction, but the number thereof can be changed as desired. The coupling holder 75 is positioned and fixed to the pump shaft 16 by screwing a set bolt 80 into the screw hole 79 and pressing the tip of the set bolt 80 against the pump shaft 16.

  Referring also to FIG. 5, the plug-in portion 65 is a cylindrical space in which the inner peripheral surface of the end portion of the motor shaft fixing portion 63 is expanded outward in the radial direction. The inner diameter of the insertion portion 65 is substantially the same as the outer diameter of the sleeve 37 and is larger than the diameter of an imaginary circle having a radius from the axis of the shaft coupling 58 to the outer end of the second key groove 64. An annular seal groove is provided in the inner peripheral portion of the insertion portion 65, and an O-ring 66 is disposed in the seal groove. The O-ring 66 is a second seal member that seals between the shaft coupling 58 and the sleeve 37.

  Referring also to FIG. 6, the first insertion hole 68 </ b> A is provided at a position different from the first key groove 60 in the circumferential direction. The second insertion hole 68B is provided at a position different from the second key groove 64 in the circumferential direction. The insertion holes 68 </ b> A and 68 </ b> B of the present embodiment are provided at intervals in the axial direction of the shaft coupling 58.

  The insertion holes 68A and 68B are provided with through portions 69 into which the knock pins 72A and 72B are driven. The through portion 69 is provided on the radially inner side of the shaft coupling 58. By placing the first knock pin 72A in the first insertion hole 68A on the pump shaft fixing portion 59 side, the shaft coupling 58 and the pump shaft 16 are fixed, and these are prevented from moving in the axial direction. By driving the second knock pin 72B into the second insertion hole 68B on the motor shaft fixing portion 63 side, the shaft coupling 58 and the motor shaft 28 are fixed, and these are prevented from moving in the axial direction. The pump shaft 16 is provided with a recess 17a corresponding to the knock pin 72A, and the motor shaft 28 is provided with a recess 29a corresponding to the knock pin 72B.

  The insertion holes 68 </ b> A and 68 </ b> B include a plug arrangement portion 70 that prevents the knock pins 72 </ b> A and 72 </ b> B from dropping off outside the through portion 69. The plug placement portion 70 is formed with a diameter larger than the diameter of the through portion 69. A screw groove is formed on the inner peripheral surface of the plug placement portion 70, and a separate plug 73 is screwed together. As for the plug 73, the liquid packing 74 is apply | coated to the outer peripheral part as a 3rd seal member. The liquid packing 74 seals between the plug 73 and the plug placement portion 70. As a result, the shaft coupling 58 is prevented from entering an external liquid through the insertion holes 68A and 68B.

(Example of connection method)
When the pump shaft 16 and the motor shaft 28 are coupled by the shaft coupling 58, for example, the coupling holder 75 is disposed in the coupling portion 17 in a state where the key 44 is not attached to the pump shaft 16. Thereafter, the key 44 is mounted on the pump shaft 16 and the spacer disk 47 is disposed. Next, the shaft coupling 58 is externally fitted to the connecting portion 17 of the pump shaft 16 from the holder mounting portion 61 side. Then, by inserting the coupling holder 75 into the holder mounting portion 61, the pump shaft 16 and the shaft coupling 58 are sealed by O-rings 77A and 77B. Further, the coupling holder 75 is in contact with the flange portion 42 of the pump shaft 16.

  Further, the sleeve 37 is externally fitted to the connecting portion 29 in a state where the first key 51 is not attached to the motor shaft 28 and the second key 53 is attached. Thereafter, after the first key 51 is attached to the motor shaft 28, the motor shaft 28 is inserted into the shaft coupling 58. Then, by inserting the end of the sleeve 37 into the insertion portion 65, the motor shaft 28 and the sleeve 37 are sealed by the O-ring 66. One end side of the sleeve 37 is in contact with the step portion 30 of the motor shaft 28, and the other end side is in contact with the end surface of the insertion portion 65. As a result, the outer peripheral portion of the connecting portion 29 located between the motor casing 22 and the shaft coupling 58 and exposed to the liquid is entirely covered by the sleeve 37.

  When the coupling portion 17 of the pump shaft 16 and the coupling portion 29 of the motor shaft 28 are thus arranged on the shaft coupling 58, knock pins 72A and 72B are driven into the insertion holes 68A and 68B. As a result, the pump shaft 16 and the motor shaft 28 are positioned and fixed with respect to the shaft coupling 58. Thereafter, the liquid packing 74 is applied to the outer peripheral portion of the plug 73, and the plug 73 is screwed into the plug placement portion 70 to seal the insertion holes 68A and 68B.

  As described above, in the submersible pump 10 of the present embodiment, the connecting portion 29 protruding from the motor casing 22 of the motor shaft 28 is covered with the sleeve 37 of the mechanical seal 35. The space between the shaft coupling 58 and the sleeve 37 and the space between the shaft coupling 58 and the pump shaft 16 are sealed in a liquid-tight manner, respectively. Therefore, it can prevent that the connection part 29 of the motor shaft 28 is exposed to the drained liquid. Therefore, the motor shaft 28 can be formed of only a magnetic material that can be rotated via the rotor 32 by passing a current through the electric wire wound around the stator 31. That is, since it is not necessary to integrally connect different forming materials, a prototype for confirming the strength is unnecessary, and the manufacturing period can be shortened and the manufacturing cost can be reduced.

  For example, when the motor shaft 28 is formed of two types of forming materials that have not been proven in combination, a trial production cost of 500 to 1,000,000 yen is required. Moreover, in order to form this prototype, a trial production period of 3 to 5 months is required. On the other hand, in the present embodiment, the motor shaft 28 can be formed only by, for example, sus420j2, which is an easily available general-purpose material, and there is no need for trial manufacture. Therefore, the manufacturing period can be greatly shortened and the manufacturing cost can be greatly reduced.

  Further, one end side of the shaft coupling 58 is arranged between the shaft coupling 58 and the coupling holder 75, and between the pump shaft 16 and the coupling by arranging O-rings 77A and 77B in a separate coupling holder 75. The space between the holders 75 is sealed. Therefore, it is possible to reliably prevent the pump shaft 16 and the shaft coupling 58 from entering the shaft coupling 58 while being relatively non-rotatably connected.

  Further, the other end side of the shaft coupling 58 seals between the shaft coupling 58 and the sleeve 37 by arranging an O-ring 66 on the inner peripheral portion of the insertion portion 65 of the sleeve 37. Therefore, it is possible to reliably prevent the sleeve 37 from being immersed in the shaft coupling 58 while positioning the sleeve 37 with respect to the shaft coupling 58.

  Further, at the intermediate portion of the shaft coupling 58, the outer end sides of the knock pins 72A and 72B for positioning and fixing the pump shaft 16 and the motor shaft 28 are sealed by the liquid packing 74. Therefore, it is possible to reliably prevent water from entering from this portion into the shaft coupling 58.

  Moreover, since the shaft coupling 58 is disposed in contact with the flange portion 42 of the pump shaft 16, the shaft coupling 58 can be reliably positioned with respect to the pump shaft 16.

  In addition, the submersible pump 10 of this invention is not limited to the structure of the said embodiment, A various change is possible.

  For example, in the embodiment, the motor casing 22 is arranged in the pump casing 12 via the connection casing 19, but the motor casing 22 may be arranged directly in the pump casing 12. In this case, the motor shaft 28 is connected to the pump shaft 16 via the shaft coupling 58 inside the pump casing 12.

  Also, a first seal member that seals between the shaft coupling 58 and the pump shaft 16, a second seal member that seals between the shaft coupling 58 and the sleeve 37, and the outer ends of the knock pins 72A and 72B are sealed. The third seal member to be performed is not limited to the O-rings 77A and 77B, the O-ring 66, and the liquid packing 74, and a desired seal member can be applied.

  Further, the configuration in which the sleeve 37 is positioned (fitted) with respect to the shaft coupling 58 is not limited to the configuration in which the insertion portion 65 is provided in the shaft coupling 58, and can be changed as desired. Further, the seal structure between the shaft coupling 58 and the pump shaft 16 is not limited to the configuration using the separate coupling holder 75 but can be changed as desired.

  In addition, the pump shaft 16 is provided with an annular flange portion 42 as a projecting portion projecting radially outward, but the projecting portion may be a projecting portion projecting at an interval in the circumferential direction. Any configuration can be used as long as the shaft coupling 58) can be brought into contact with the shaft coupling 58).

DESCRIPTION OF SYMBOLS 10 ... Submersible pump 12 ... Pump casing 13 ... Suction port 14 ... Discharge port 15 ... Bearing 16 ... Pump shaft 17 ... Connection part 17a ... Recess 18 ... Impeller 19 ... Connection casing 20 ... Water resistant motor 22 ... Motor casing 23 ... Outer wall 24 DESCRIPTION OF SYMBOLS ... 1st cover member 25 ... Insertion part 26 ... 2nd cover member 27 ... Thrust bearing 28 ... Motor shaft 29 ... Connection part 29a ... Recessed part 30 ... Step part 31 ... Stator 32 ... Rotor 33 ... Pressure control device 35 ... Mechanical Seal 36 ... Housing 37 ... Sleeve 38 ... Fixed ring 39 ... Rotating ring 40 ... Slinger 42 ... Flange (projection)
43 ... Key mounting portion 44 ... Key 45 ... Screw hole 47 ... Spacer disk 48 ... Screw portion 50 ... First key mounting portion 51 ... First key 52 ... Second key mounting portion 53 ... Second key 55 ... Key groove 58 ... Shaft coupling 59 ... Pump shaft fixing part 60 ... First key groove 61 ... Holder mounting part 63 ... Motor shaft fixing part 64 ... Second key groove 65 ... Insertion part 66 ... O-ring (second seal member)
68A, 68B ... insertion hole 69 ... penetration part 70 ... plug arrangement part 72A, 72B ... knock pin 73 ... plug 74 ... liquid packing (third seal member)
75 ... Coupling holder 76 ... Insertion section 77A, 77B ... O-ring (first seal member)
78 ... Flange 79 ... Screw hole 80 ... Set bolt

Claims (5)

A pump shaft made of a corrosion-resistant material rotatably arranged in the pump casing;
A motor shaft made of a magnetic material protruding from the motor casing to the pump casing side so as to be located on the same axis as the pump shaft;
A mechanical seal that seals between the motor casing and the motor shaft;
A shaft coupling integrally connecting the pump shaft and the motor shaft;
The mechanical seal has a sleeve covering the outer periphery of the motor shaft from the motor casing to the shaft coupling,
Wherein between the one end of the shaft coupling and the pump shaft is sealed by the first seal member, between the other end and the sleeve of the shaft coupling is sealed by a second sealing member, the water pump .   The insertion part which inserts the said sleeve is provided in the said other end side of the said shaft coupling, The said 2nd seal member is arrange | positioned at the inner peripheral part of the said insertion part. underwater pump. The pump shaft has a key projecting radially outward;
3. The submersible pump according to claim 1, wherein the shaft coupling has a separate coupling holder in which the first seal member is disposed on the one end side.   The submersible pump according to claim 3, wherein the pump shaft has a protruding portion that protrudes radially outward, and the coupling holder is disposed in contact with the protruding portion. The shaft coupling is fixed with a first knock pin through a first insertion hole to the pump shaft, and is fixed with a second knock pin through a second insertion hole to the motor shaft,
The submersible pump according to any one of claims 1 to 4, wherein outer ends of the first insertion hole and the second insertion hole are sealed by a third seal member.

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