Submerged pump

Abstract

To provide a submerged pump which prevents over-fastening of fastening components to a waterproof cover for watertightly sealing a motor case, is easily assembled by just adjusting a thread fastening quantity, and is improved in waterproofness.SOLUTION: A pump case 2 of a motor case 3 is assembled by overlapping a waterproof cover 5 and a back cover 6 at an axial opening end on an opposite side. A motor base plate 3m electrically connected to a stator 3B is housed in an internal space of the motor case 3 closed by the waterproof cover 5 and the back cover 6. A lead wire 3p connected to the motor base plate 3m penetrates the back cover 6 by inserting a tube-like lead wire taking-out port 5f formed integrally with the waterproof cover 5, and is taken out to the outside of the motor case 3.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a submersible pump that, for example, washes a toilet bowl placed in a water tank of a flush toilet or discharges water while being placed in flooded water.

Background Art

[0002] A motor and an impeller rotationally driven thereby are provided in a case of a pump body, and there is a water passage surrounding the impeller. Water sucked in from a suction port is pumped by the rotating impeller and discharged from a discharge port. The periphery of the motor is covered with a waterproof cover made of rubber or vinyl chloride. The waterproof cover is assembled with a flange portion overlapping the case of the pump body and a plurality of screws threadedly engaged to maintain a watertight state. Further, a tubular portion through which an electric cord penetrates extends from the waterproof cover, and a stainless steel clamping ring is fitted to the tubular portion to crimp the tubular portion to the electric cord to maintain a watertight state (Patent Document 1; Japanese Utility Model Publication No. 51-14322).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the waterproof cover of the above-mentioned Citation Document 1 is tightened with screws to the case of the pump body, it is necessary for an operator to control the tightening amount of the screws. If the screws are tightened too much, the rubber or resin waterproof cover is likely to bend, so that a gap due to bending may occur and water may enter. Also, if the screws are tightened loosely, there is a risk of water entering through the gap generated between the waterproof cover and the case. The same applies to the metal clamping ring fitted to the tubular portion of the waterproof cover through which the electric cord is taken out.

Means for Solving the Problems

[0005] The present invention has been made to solve these problems, and an object thereof is to provide a submersible pump that is easy to assemble and has improved waterproof performance by preventing over-tightening of fastening parts for a waterproof cover that watertightly seals a motor case and adjusting the screw tightening amount without excess or deficiency.

[0006] To achieve the above object, the present invention has the following configuration. A pump unit having a suction port for sucking stored water at the central part of the pump case, a discharge port for discharging the pressurized water flow at the outer peripheral part of the pump case, and an impeller for pressurizing the stored water sucked from the suction port in the pump case and discharging it from the discharge part; a rotor in which rotor magnetic poles are concentrically provided around a rotor shaft housed in a cylindrical motor case assembled to the pump case; and a drive unit having a stator provided with stator magnetic poles facing the rotor magnetic poles, wherein one end side of the rotor shaft housed in the motor case extends to the pump case side to serve as a rotation shaft of the impeller, and a waterproof cover and a back cover are overlapped and assembled to an axial opening end portion of the motor case on the side opposite to the pump case, and a motor board electrically connected to the stator is housed in an internal space of the motor case closed by the waterproof cover and the back cover, and a tubular lead wire extraction port through which a lead wire connected to the motor board is inserted penetrates the back cover and is integrally formed with the waterproof cover. Thus, since the waterproof cover and the back cover are overlapped and assembled to the axial opening end portion of the cylindrical motor case on the side opposite to the pump case, the waterproof performance of the motor case can be enhanced. Since the lead wire connected to the motor board is inserted through the tubular lead wire extraction port integrally formed with the waterproof cover, penetrates the back cover, and is taken out, and the lead wire extraction port can be easily closed by being easily crimped to the lead wire, it is possible to prevent a decrease in waterproof performance due to over-tightening by the fastening parts of the waterproof cover.

[0007] A waterproof case that covers the periphery of the rotor and partitions the space between the stator is integrally assembled between the pump case and the motor case, and it is preferable that the stator and the motor substrate are accommodated in the cylindrical motor case whose both side openings are closed by the waterproof case and the waterproof cover. In this way, the rotor and the stator are partitioned and arranged by the waterproof case in the motor case, thereby improving the waterproofness of the electrical components accommodated in the cylindrical motor case whose both side openings are closed by the waterproof case and the waterproof cover.

[0008] The water stop protrusion protruding axially along the opening end of the waterproof cover is crushed against the opening end of the motor case facing it, and the cover protrusion protruding from the opening end of the back cover is axially abutted against the opening end of the motor case exposed from the waterproof cover. The pump case, the motor case, and the back cover may be screwed and fixed at a plurality of locations in the circumferential direction. In this way, since the waterproof cover and the back cover are axially overlapped and assembled at the opening end of the cylindrical motor case, the waterproofness of the motor case is improved by crushing the water stop protrusion of the waterproof cover with the back cover. In particular, since the cover protrusion is abutted against the axially opening end of the motor case exposed from the waterproof cover and the pump case, the motor case, and the back cover are screwed and fixed at a plurality of locations in the circumferential direction, there is no variation in the tightening amount that is too tight or too loose by the operator, and the crushing amount of the water stop protrusion can be assembled without variation.

[0009] A first flange portion and a second flange portion are provided continuously with a step from the radially inner side toward the radially outer side at the opening end of the motor case, and the waterproof cover may be provided with a seal portion in which a water stop protrusion pressed against the first flange portion and a seal protrusion pressed against the second flange portion are provided continuously via a circumferential groove. As a result, when the pump case, the motor case, and the back cover are screwed together, the water-stop protrusion pressed against the first flange portion is crushed so as to fill the circumferential groove, and the seal protrusion continuous with the water-stop protrusion is pressed against the second flange portion continuous with the first flange portion via a step. Therefore, the waterproof property of the motor case is improved by the deformation of the water-stop protrusion of the waterproof cover and the labyrinth structure of the seal protrusion continuous therewith.

[0010] A plurality of through holes are drilled in the second flange portion of the motor case, and in the seal portion of the waterproof cover, enlarged through holes that communicate with the through holes and expand radially outward from each through hole are provided respectively. In the back cover, screw holes that communicate with the through holes and the enlarged through holes are provided respectively in a fixing portion that overlaps the seal portion. The enlarged through holes and the screw holes are aligned with the through holes of the motor case, and the seal portion and the fixing portion are overlapped on the second flange portion. It is preferable that the cover protrusions protruding from the fixing portion along the outer peripheral edge portion of the enlarged through hole are respectively abutted against the second flange portion exposed from the enlarged through hole. As a result, when the pump case, the motor case, and the back cover are screwed together, the cover protrusions protruding from the fixing portion along the outer peripheral edge portion of the enlarged through hole are respectively abutted against the second flange portion exposed from the enlarged through hole. Therefore, there is no variation in the amount of screwing, and moreover, the outer peripheral side of the cover protrusion can be surrounded by the seal protrusion, and the waterproof property of the motor case can be enhanced.

Effects of the Invention

[0011] It is possible to provide a submersible pump that prevents over-tightening of the tightening component for the waterproof cover that hermetically seals the motor case, easily adjusts the amount of screwing without excess or deficiency, and improves the waterproof property.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0013] Hereinafter, an embodiment of the submersible pump according to the present invention will be described with reference to the accompanying drawings. First, the configuration of the submersible pump 1 will be described with reference to FIGS. 1 to 6. The submersible pump 1 has the pump case 2, the waterproof case 4, and the motor case 3 stacked axially, and the waterproof cover 5 and the back cover 6 are sequentially stacked on the motor case 3, and the sleeve bolts 7 provided at four locations in the circumferential direction are screwed and assembled integrally.

[0014] A suction port 2a for sucking stored water is provided protruding at the center of the pump case 2. In addition, a discharge port 2b for discharging the pressurized water flow is provided on the outer peripheral portion of the pump case 2. An impeller 2c is rotatably accommodated in the pump case 2 (pump section; see FIG. 6). When the impeller 2c rotates, the stored water is sucked into the pump case 2 from the suction port 2a, pressurized by the impeller 2c, and discharged from the discharge port 2.

[0015] In Fig. 8, a waterproof case 4 that covers the rotor 3A and partitions it from the stator 3B is integrally assembled between the pump case 2 and the motor case 3. The stator 3B is assembled in the motor case 3 partitioned by the waterproof case 4, and a motor substrate 3m that is electrically connected to the stator 3B is accommodated in a back cover 6 assembled to the motor case 3. Thus, inside the motor case 3, the rotor 3A and the stator 3B are partitioned and arranged by the waterproof case 4, so that the waterproofness of the electrical components accommodated in the cylindrical motor case 3 with both side openings closed by the waterproof case 4 and the waterproof cover 5 is improved.

[0016] The rotor 3A is accommodated in the waterproof case 4. The rotor 3A has a rotor yoke 3e and rotor magnets 3f (rotor poles) provided concentrically around a rotor shaft 3c via bearings 3d. The rotor magnets 3f have N poles and S poles formed alternately in the circumferential direction. One end side of the rotor shaft 3c extends toward the pump case 2 side and serves as the rotation shaft of the impeller 2c. The other end side of the rotor shaft 3c is supported by the waterproof case 4 that has entered the motor case 3 in a nested manner. In this way, inside the motor case 3, the rotor 3A and the stator 3B are partitioned and arranged by the waterproof case 4, so that the waterproofness of the stator 3B and electrical components such as the motor substrate 3m electrically wired and connected thereto is improved. Note that the rotor yoke 3e and the impeller 2c may be integrally formed or separately assembled as shown in Fig. 8.

[0017] In addition, a cylindrical motor case 3 is axially stacked and assembled on a waterproof case 4. A stator 3B is assembled on the motor case 3. Specifically, an annular core back portion 3h formed on a stator core 3g is adhesively fixed to an inner wall surface of the motor case 3. A motor coil 3k is wound around a pole tooth (tooth portion) 3i extending radially inward from the back yoke 3h via an insulator 3j. A magnetic flux acting surface of the pole tooth 3i is disposed to face a rotor magnet 3f via the waterproof case 4 (see FIG. 7). Further, an insulator 3j holds a motor substrate 3m in which an energization circuit for energizing the motor coil 3k is formed (drive unit; see FIG. 8).

[0018] As shown in FIG. 8, a waterproof cover 5 and a back cover 6 are stacked and assembled at an axially open end portion of the motor case 3 on the side opposite to the pump case 2. A motor substrate 3m electrically connected to the stator 3B is accommodated in an internal space of the motor case 3 closed by the waterproof cover 5 and the back cover 6. As shown in FIG. 9, a tubular lead wire extraction port 5f through which a lead wire 3p connected to the motor substrate 3m is inserted is formed integrally with the waterproof cover 5 through the back cover 6. Since the lead wire extraction port 5f extends outside through the back cover 6, the lead wire 3p connected to the motor substrate 3m is drawn out of the motor case 3 by inserting through the lead wire extraction port 5f.

[0019] In this way, since the waterproof cover 5 and the back cover 6 are assembled by overlapping them at the axially open end on the side opposite to the pump case 2 of the cylindrical motor case 3, the waterproof property of the motor case 3 can be enhanced. Since the lead wire 3p connected to the motor substrate 3m passes through the tubular lead wire outlet 5f formed integrally with the waterproof cover 5 and penetrates through the back cover 6 and is taken out, it is easy to crimp the lead wire outlet 5f to the lead wire 3p and it can be easily closed using an adhesive or the like. Therefore, it is possible to prevent a decrease in waterproof property due to over-tightening by the fastening parts of the waterproof cover 5. As described above, since the watertightness of the space portion on the other axial end side of the motor is high, it is possible to provide an electrical equipment system such as the motor substrate 3m and a wiring mechanism without worrying about water immersion.

[0020] As shown in FIG. 10, at the open end on the other axial end side of the motor case 3, a first flange portion 3b1 and a second flange portion 3b2 are provided continuously with a step from the radially inner side toward the radially outer side. The waterproof cover 5 is provided with a seal portion 5a in which a water stop protrusion 5c pressed against the first flange portion 3b1 and a seal protrusion 5d pressed against the second flange portion 3b2 are connected via a circumferential groove 5e. Thereby, as shown in FIG. 10, when the pump case 2, the motor case 3, and the back cover 6 are screwed together, the water stop protrusion 5c pressed against the first flange portion 3b1 is crushed so as to fill the circumferential groove 5e, and the seal protrusion 5d connected to the water stop protrusion 5c is pressed against the second flange portion 3b2 connected to the first flange portion 3b1 via a step. Therefore, the waterproof property of the motor case 3 is improved by the deformation of the water stop protrusion 5c of the waterproof cover 5 and the labyrinth structure of the seal protrusion 5d connected thereto.

[0021] As shown in FIG. 7, a plurality of (for example, four) through holes 3n are drilled in the circumferential direction in the second flange portion 3b2 of the motor case 3. The seal portion 5a of the waterproof cover 5 is provided with enlarged through holes 5b that communicate with the through holes 3n and are enlarged radially outside each through hole 3n. As shown in FIG. 8, the back cover 6 is provided with screw holes 6b that communicate with the through holes 3n and the enlarged through holes 5b in a fixing portion 6a that overlaps the seal portion 5a.

[0022] As shown in FIG. 10, the waterproof cover 5 and the back cover 6 are overlapped by aligning the enlarged through-hole 5b and the screw hole 6b with respect to the through-hole 3n of the motor case 3. At this time, cover protrusions 6c protruding from the fixing portion 6a along the outer peripheral edge of the enlarged through-hole 5b are respectively abutted against the second flange portion 3b2 exposed from the enlarged through-hole 5b. On the outer side and the inner side in the radial direction of the enlarged through-hole 5b provided in the seal portion 5a, annular seal protrusions 5d that fit into the stepped portion 3b3 provided in the second flange portion 3b2 are provided.

[0023] Thereby, when the pump case 2, the motor case 3, and the back cover 6 are screwed together, the water stop protrusion 5c is pressed against the first flange portion 3b1, and the cover protrusions 6c protruding from the fixing portion 6a along the outer peripheral edge of the enlarged through-hole 5b are respectively abutted against the second flange portion 3b2 exposed from the enlarged through-hole 5b. Therefore, there is no variation in the amount of screwing, and moreover, the outer peripheral side of the cover protrusion 6c can be surrounded by the seal protrusion 5d, thereby enhancing the waterproof property of the motor case 3.

[0024] As shown in FIG. 10, a screw groove is provided in the screw hole 6b provided in the back cover 6, and the screw portion 7a provided at the tip of the sleeve bolt 7 is screwed and fitted. The waterproof cover 5 and the back cover 6 are overlapped with respect to the motor case 3 by aligning the through-hole 3n, the enlarged through-hole 5b, and the screw hole 6a with each other. At the peripheral edge of the through-hole 3n of the second flange portion 3b2, the cover protrusion 6c is surrounded by the seal protrusion 5d on the outer peripheral side and is respectively abutted against the second flange portion 3b2 exposed from the enlarged through-hole 5b and is screwed to the sleeve bolt 7.

[0025] In this way, since the waterproof cover 5 and the back cover 6 are axially overlapped and assembled at the axially open end of the motor case 3, the waterproof property is improved by crushing and assembling the waterproof cover 5 (waterstop projection 5c) with the back cover 6. In particular, since the cover projection 6c is abutted against the axially open end of the motor case 3 that is exposed from the waterproof cover 5, and the pump case 2, the motor case 3, and the back cover 6 are screwed and fixed at a plurality of locations in the circumferential direction, there is no variation in the tightening amount that is too tight or too loose by the operator, and the crushing amount of the waterstop projection 5c can be assembled without variation. Further, the waterproof property of the motor case 3 is improved by the deformation of the waterstop projection 5c of the waterproof cover 5 and the labyrinth structure of the seal projection 5d connected thereto. Furthermore, the waterproof property of the motor case 3 can also be enhanced by surrounding the outer peripheral side of the cover projection 6c abutted against the second flange portion 3b2 exposed from the enlarged through-hole 5b with the seal projection 5d.

[0026] The submersible pump 1 described above is expected to be used in water such as a storage tank of a flush toilet or a drainage pump, for example, and a highly reliable submersible pump 1 can be provided without impairing the waterproof property of the drive unit.

Explanation of Reference Numerals

[0027] 1 Submersible pump 2 Pump case 2a Suction port 2b Discharge port 2c Impeller 3 Motor case 3A Rotor 3B Stator 3 Motor case 3b1 First flange portion 3b2 Second flange portion 3b3 Step portion 3c Rotor shaft 3d Bearing 3e Rotor yoke 3f Rotor magnet 3g Stator core 3h Core back portion 3i Pole tooth 3j Insulator 3k Motor coil 3m Motor substrate 3n Through-hole 3p Lead wire 4 Waterproof case 5 Waterproof cover 5a Seal portion 5b Enlarged through-hole 5c Waterstop projection 5d Seal projection 5e Circumferential groove 5f Lead wire extraction port 6 Back cover 6a Fixed portion 6b Screw hole 6c Cover projection 7 Sleeve bolt 7a Screw portion

Claims

1. A pump unit having a suction port for sucking stored water at the central part of the pump case and a discharge port for discharging the pressurized water flow at the outer peripheral part of the pump case, and an impeller for pressurizing the stored water sucked from the suction port in the pump case and discharging it from the discharge part; and a rotor in which rotor magnetic poles are provided concentrically around a rotor shaft housed in a cylindrical motor case assembled to the pump case, and a drive unit having a stator provided with stator magnetic poles facing the rotor magnetic poles, and one end side of the rotor shaft housed in the motor case extends to the pump case side to serve as a rotation shaft of the impeller, an underwater pump, A waterproof cover and a back cover are assembled by overlapping them at the axially open end of the motor case on the side opposite to the pump case, and a motor board electrically connected to the stator is housed in the internal space of the motor case closed by the waterproof cover and the back cover, and a tubular lead wire extraction port through which a lead wire connected to the motor board is inserted penetrates the back cover and is integrally formed with the waterproof cover. Underwater pump.

2. A waterproof case that covers the periphery of the rotor and partitions the space from the stator is integrally assembled between the pump case and the motor case, and the stator and the motor board are housed in the cylindrical motor case with both side openings closed by the waterproof case and the waterproof cover. The underwater pump according to claim 1.

3. When a water stop protrusion projecting axially along the opening end of the waterproof cover is crushed against the opening end of the motor case facing it, and a cover protrusion projecting from the opening end of the back cover is abutted axially against the opening end of the motor case exposed from the waterproof cover, the pump case, the motor case, and the back cover are screwed and fixed at a plurality of locations in the circumferential direction. The underwater pump according to claim 1 or claim 2.

4. A first flange portion and a second flange portion are provided continuously from the radially inner side to the radially outer side at the opening end of the motor case with a step therebetween, and the waterproof cover is provided with a seal portion in which a water stop protrusion pressed against the first flange portion and a seal protrusion pressed against the second flange portion are provided continuously via a circumferential groove. The submersible pump according to claim 1 or claim 2.

5. A plurality of through holes are drilled in the circumferential direction in the second flange portion of the motor case, and the seal portion of the waterproof cover is provided with enlarged through holes that communicate with the through holes and expand radially outward from each through hole. The back cover is provided with screw holes that communicate with the through holes and the enlarged through holes in a fixing portion that overlaps the seal portion. The enlarged through holes and the screw holes are aligned with the through holes of the motor case, and the waterproof cover portion and the back cover are overlapped. The cover protrusions protruding from the fixing portion along the outer peripheral edge of the enlarged through hole are respectively abutted against the second flange portion exposed from the enlarged through hole. The submersible pump according to claim 4.

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