JP7159896B2 - underwater pump - Google Patents

Description

The present invention relates to submersible pumps.

Conventionally, a submersible pump provided with a mechanical seal is known (see Patent Document 1, for example).

The above Patent Document 1 discloses a motor that rotates an impeller arranged in a pump chamber via a rotating shaft, a mechanical seal arranged in an oil chamber between the pump chamber and the motor, and a liquid flowing into the pump chamber. A submersible pump is disclosed that includes an inlet that allows the air to flow. The suction port is arranged directly below the impeller (on the side opposite to the motor side of the impeller in the axial direction of the rotating shaft). A submersible pump rotates an impeller in order to allow liquid to flow in from the suction port, thereby creating a negative pressure on the suction port side of the impeller and on the side opposite to the suction port side of the impeller (mechanical seal side). is pressurized (positive pressure).

Japanese Patent Application Laid-Open No. 2002-310091

However, in the submersible pump of Patent Document 1, the side opposite to the suction port side (mechanical seal side) of the impeller is pressurized (positive pressure). There is a problem that water is likely to flow from the pump chamber into the oil chamber due to the pressure applied to the sliding portion of the mechanical seal in the direction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a submersible pump capable of suppressing water from entering the oil chamber from the pump chamber. be.

A submersible pump according to one aspect of the present invention comprises a motor, a suction port for inflowing liquid into a pump chamber, a base attached to a rotating shaft rotationally driven by the motor, and a suction port at the base in the axial direction of the rotating shaft. An impeller arranged in the pump chamber, and a sliding portion that slides with the rotation of the rotating shaft, arranged in the oil chamber between the pump chamber and the motor. a mechanical seal ; and a rib portion that forms a suction passage having a constant width in the axial direction and linearly extending from the suction port to an end on the rotating shaft side in a direction perpendicular to the axial direction, the suction port is configured to allow liquid to flow into the pump chamber from a direction intersecting the axial direction, and is arranged at a position closer to the mechanical seal than the impeller in the axial direction, and the upper end of the suction port in the axial direction is It is arranged below the lower end of the mechanical seal, and in the direction perpendicular to the axial direction, the end of the rib portion on the rotating shaft side is arranged closer to the suction port than the end of the blade portion on the rotating shaft side. .

In the submersible pump according to one aspect of the present invention, by being configured as described above, in the axial direction of the rotating shaft, the liquid flows into the pump chamber from the suction port between the mechanical seal and the impeller, and the impeller allows the liquid to flow away from the mechanical seal. In other words, contrary to the conventional case where the suction port is arranged directly under the impeller, the mechanical seal side of the impeller is made negative pressure to flow the liquid to the impeller side, and the mechanical seal side of the impeller can put the opposite side into a pressurized state (positive pressure). As a result, it is possible to suppress the application of pressure from the pump chamber side to the oil chamber side so as to press the sliding portion of the mechanical seal, so it is possible to suppress water from entering the oil chamber from the pump chamber. . In the axial direction, the suction port is arranged closer to the mechanical seal than the impeller. Ingress of water from the pump chamber to the oil chamber can be suppressed.

In the submersible pump according to the above aspect, preferably, the portion of the pump chamber on the oil chamber side is configured to have a negative pressure due to the rotation of the impeller. According to this configuration, it is possible to suppress the pressure from being applied in the direction from the pump chamber side to the oil chamber side by the negative pressure generated by the rotation of the impeller so as to push the sliding portion of the mechanical seal. Therefore, it is possible to suppress water from entering the oil chamber from the pump chamber.

The submersible pump according to the above aspect preferably further includes a discharge port for discharging liquid from the pump chamber, and the suction port is arranged at a position that does not overlap with the discharge port in the axial direction. With this configuration, compared to the case where the suction port overlaps the discharge port in the axial direction, the liquid flowing in from the suction port moves away from the mechanical seal (in the axial direction toward the impeller). ) can be effectively generated. That is, it is possible to generate a region that is in a pressurized state at a position further away from the mechanical seal. As a result, the ingress of water from the pump chamber into the oil chamber can be more effectively suppressed.

In this case, preferably, the suction port is arranged at a position closer to the mechanical seal than the discharge port in the axial direction. According to this structure, the area to be pressurized can be generated at a position farther apart from the mechanical seal, so that the ingress of water from the pump chamber into the oil chamber can be further suppressed.

In the submersible pump according to the above one aspect, the opening area of the suction port is preferably larger than the area of the cross section of the rotating shaft orthogonal to the axial direction. With this configuration, a relatively large opening area of the suction port can be ensured, so that the liquid can effectively flow into the pump chamber.

In the submersible pump according to the above one aspect, the opening area of the suction port is preferably substantially the same size as the area of the inner region of the inner diameter at the end of the blade portion on the suction port side. With this configuration, an amount of liquid suitable for the specifications of the impeller can be made to flow from the suction port.

The submersible pump according to the above aspect preferably further includes a discharge port for discharging liquid from the pump chamber, and the suction port and the discharge port are arranged on one side and the other side of the rotating shaft, respectively. With this configuration, compared to the case where the suction port and the discharge port are arranged on the same side of the rotating shaft, liquid flows in the order of the suction port, the impeller, and the discharge port when viewed from the axial direction of the rotating shaft. It is possible to suppress a large change in the direction of That is, the liquid can flow efficiently in the pump chamber.

According to the present invention, as described above, it is possible to provide a submersible pump capable of suppressing water from entering the oil chamber from the pump chamber.

1 is a schematic side view showing a cross-sectional shape of a submersible pump according to one embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

[Embodiment]
(Construction of submersible pump)
A submersible pump 100 according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the submersible pump 100 includes a motor 1, a rotating shaft 2, a pump chamber 3, an impeller 4, an oil chamber 5, and a mechanical seal 6. The submersible pump 100 also includes a suction port 7 for inflow of liquid into the pump chamber 3 and a discharge port 8 for outflow of liquid from the pump chamber 3 . The submersible pump 100 is a vertical submersible pump in which the rotating shaft 2 extends vertically.

In each figure, the axial direction of the rotating shaft 2, that is, the vertical direction is shown as the Z direction. In addition, among the Z directions, the upward direction is indicated as the Z1 direction, and the downward direction is indicated as the Z2 direction.

The motor 1 is sealed so that water does not enter from the outside. The motor 1 is also configured to rotationally drive an impeller 4 connected to the rotating shaft 2 via the rotating shaft 2 . Specifically, motor 1 includes a stator 11 and a rotor 12 . The stator 11 is arranged outside (peripheral side) of the rotor 12 . The stator 11 has coils (not shown). Further, the stator 11 is configured to generate a magnetic field when power is supplied from the cable C. As shown in FIG. Rotor 12 is attached to rotating shaft 2 and arranged inside (inner peripheral side) of stator 11 so as to face stator 11 . That is, the motor 1 is an inner rotor motor. Also, the rotor 12 is configured to rotate together with the rotating shaft 2 by the magnetic field from the stator 11 . The rotor 12 is configured to rotate the impeller 4 via the rotating shaft 2 .

The rotating shaft 2 is configured to be rotated by being driven by the motor 1 . Further, the rotating shaft 2 is configured to transmit the driving force (torque) of the motor 1 to the impeller 4 . Further, the rotary shaft 2 is rotatably supported by bearings 21 and 22 . Further, the rotating shaft 2 is arranged to extend from the motor 1 through the oil chamber 5 to the pump chamber 3 . An impeller 4 is attached to the end (Z2 direction end) of the rotating shaft 2 opposite to the motor 1 side end (Z1 direction end).

An impeller 4 is arranged in the pump chamber 3 . The pump chamber 3 is configured such that liquid flows in from the suction port 7 and flows out from the discharge port 8 as the impeller 4 rotates.

The impeller 4 is attached to a rotating shaft 2 that is rotationally driven by the motor 1 . The impeller 4 includes a base portion 41 and blade portions 42 .

The base 41 is attached to the rotating shaft 2 and configured to rotate together with the rotating shaft 2 . The base 41 has a disc shape extending in a direction orthogonal to the axial direction (Z direction) of the rotating shaft 2 . The blade portion 42 is provided on the suction port 7 side (Z1 direction side) of the base portion 41 in the axial direction (Z direction) of the rotating shaft 2 . The blade portion 42 is composed of a single blade or a plurality of blades.

The impeller 4 is configured to generate a negative pressure in the vicinity of the suction port 7 side (Z1 direction side) of the impeller 4 in the axial direction (Z direction) of the rotating shaft 2 by being rotationally driven. . At the same time, the impeller 4 is configured to generate a positive pressure near the opposite side (Z2 direction side) of the impeller 4 to the suction port 7 side in the axial direction (Z direction) of the rotating shaft 2. . That is, the impeller 4 is configured to pressurize the vicinity of the side (Z2 direction side) opposite to the suction port 7 side of the impeller 4 in the axial direction (Z direction) of the rotating shaft 2. . As a result, the impeller 4 draws in the fluid that has flowed in from the suction port 7 and generates a flow toward the discharge port 8 . Therefore, the portion of the pump chamber 3 on the oil chamber 5 side is configured to have a negative pressure due to the rotation of the impeller 4 .

The above-mentioned negative pressure and positive pressure mean negative pressure and positive pressure, respectively, with the static water pressure at a water depth substantially equal to that of the impeller 4 as a reference water pressure. In addition, in the axial direction (Z direction) of the rotating shaft 2 , the suction port 7 side (Z1 direction side) of the impeller 4 is the oil chamber 5 side (mechanical seal 6 side) of the impeller 4 .

The oil chamber 5 is arranged between the pump chamber 3 and the motor 1 . The oil chamber 5 is filled with oil. A mechanical seal 6 is arranged in the oil chamber 5 .

The mechanical seal 6 includes sliding portions 6a and 6b that slide as the rotating shaft 2 rotates, a fixed member 61, a rotating member 62, and a spring 63. As shown in FIG.

The sliding portion 6 a is provided on the non-load side of the mechanical seal 6 , that is, on the motor 1 side (upper side) of the oil chamber 5 . Therefore, the sliding portion 6a prevents the oil in the oil chamber 5 from flowing into the motor 1 (motor chamber) side.

The sliding portion 6b is provided on the load side of the mechanical seal 6, that is, on the pump chamber 3 side of the oil chamber 5 (Z2 direction side). Therefore, the sliding portion 6 b prevents the liquid in the pump chamber 3 from flowing into the oil chamber 5 .

The fixed member 61 is fixed to the inner wall of the oil chamber 5 . Moreover, the fixing member 61 is formed in an annular shape so as to surround the rotating shaft 2 . The rotating member 62 is attached to the rotating shaft 2 . That is, the rotating member 62 is configured to rotate together with the rotating shaft 2 . Moreover, the rotating member 62 is formed in an annular shape so as to surround the rotating shaft 2 . Also, the rotating member 62 is biased toward the fixed member 61 by a spring 63 . The fixed member 61 and the rotating member 62 are arranged so as to face each other in the axial direction of the rotating shaft 2 .

The stationary member 61 and the rotating member 62 respectively have sliding surfaces 611 and 621 between the stationary member 61 and the rotating member 62 . That is, in the sliding portions 6a and 6b, the sliding surface 611 of the fixed member 61 and the sliding surface 621 of the rotating member 62 are configured to slide on each other. Further, the space between the sliding surfaces 611 and 621 is configured so that a small amount of oil in the oil chamber 5 enters. As a result, the sliding surfaces 611 and 621 are lubricated, and the sliding portions 6a and 6b (oil chamber 5) are sealed.

The suction port 7 (suction channel) is configured to allow liquid to flow into the pump chamber 3 from a direction intersecting the axial direction (Z direction) of the rotating shaft 2 . The suction port 7 is arranged at a position closer to the mechanical seal 6 than the impeller 4 (position on the Z1 direction side) in the axial direction (Z direction) of the rotating shaft 2 . That is, in the axial direction (Z direction) of the rotating shaft 2, the distance D1 between the upper end of the suction port 7 and the lower end of the mechanical seal 6 is the same as the lower end of the suction port 7 and the upper end of the impeller 4 (a blade portion 42 described later). is less than the distance D2 between the end 42a) of the .

In addition, the suction port 7 is arranged at a position that does not overlap with the discharge port 8 in the axial direction (Z direction) of the rotating shaft 2 . Further, the suction port 7 is arranged at a position closer to the mechanical seal 6 (position on the Z1 direction side) than the discharge port 8 in the axial direction (Z direction) of the rotating shaft 2 .

A flow passage cross section of the suction port 7 (broken line portion in FIG. 1) is formed in a circular shape. The opening area S1 of the suction port 7 is larger than the area S2 of the cross section of the rotating shaft 2 orthogonal to the axial direction (Z direction) of the rotating shaft 2 . The opening area S1 of the suction port 7 has substantially the same size as the opening area of the discharge port 8 . Furthermore, the opening area S1 of the suction port 7 is substantially the same as the area S3 of the inner region of the inner diameter (liquid intake port of the impeller 4) at the end 42a of the blade portion 42 on the suction port 7 side (Z1 direction side). It's size.

The suction port 7 and the discharge port 8 are arranged on one side and the other side of the rotary shaft 2, respectively. That is, the suction port 7 and the discharge port 8 are arranged so as to sandwich the rotating shaft 2, and in plan view (as seen from the Z direction), the center line (not shown) between the suction port 7 and the discharge port 8 are arranged on substantially the same straight line.

The submersible pump 100 is provided with a rib portion 9 extending along the suction port 7 so as to protrude inward from the inner surface of the housing forming the pump chamber 3 on the impeller 4 side of the suction port 7 . there is The rib portion 9 guides the liquid flowing from the suction port 7 to the vicinity of the rotating shaft 2 before reaching the vicinity of the impeller 4 . The rib portion 9 causes the submersible pump 100 to generate a liquid flow in the pump chamber 3 toward the impeller 4 from substantially directly above the impeller 4 (Z1 direction side).

(Effect of Embodiment)
The following effects can be obtained in this embodiment.

In the present embodiment, as described above, in the axial direction of the rotating shaft 2, the liquid is caused to flow into the pump chamber 3 from the suction port 7 between the mechanical seal 6 and the impeller 4, and the impeller 4 causes the mechanical seal 6 to flow. The liquid can flow away from the That is, contrary to the conventional case where the suction port 7 is arranged directly under the impeller 4, the mechanical seal 6 side of the impeller 4 is made negative pressure to flow the liquid to the impeller 4 side, 4 can be pressurized (positive pressure) on the side opposite to the mechanical seal 6 side. As a result, it is possible to suppress the pressure from being applied in the direction from the pump chamber 3 side to the oil chamber 5 side so as to press the sliding portion 6b of the mechanical seal 6. can be suppressed. Since the suction port 7 is located closer to the mechanical seal 6 than the impeller 4 in the axial direction, the mechanical seal 6 can be further separated from the pressurized region of the pump chamber 3. , the ingress of water from the pump chamber 3 to the oil chamber 5 can be effectively suppressed.

In this embodiment, as described above, the portion of the pump chamber 3 on the oil chamber side is configured to have a negative pressure due to the rotation of the impeller 4 . As a result, it is possible to suppress the negative pressure generated by the rotation of the impeller 4 from applying pressure that pushes the sliding portion 6b of the mechanical seal 6 in the direction from the pump chamber 3 side to the oil chamber 5 side. . Therefore, it is possible to prevent water from entering the oil chamber 5 from the pump chamber 3 .

In the present embodiment, as described above, the discharge port 8 for discharging the liquid from the pump chamber 3 is further provided, and the suction port 7 is arranged at a position that does not overlap with the discharge port 8 in the axial direction. As a result, compared to the case where the suction port 7 overlaps the discharge port 8 in the axial direction, the liquid flowing in from the suction port 7 is directed away from the mechanical seal 6 (the axis toward the impeller 4). direction) can be effectively generated. That is, the area to be pressurized can be generated at a position further away from the mechanical seal 6 . As a result, the ingress of water from the pump chamber 3 to the oil chamber 5 can be suppressed more effectively.

In this embodiment, as described above, the suction port 7 is arranged at a position closer to the mechanical seal 6 than the discharge port 8 in the axial direction. As a result, the pressurized region can be generated at a position farther apart from the mechanical seal 6 , so that the ingress of water from the pump chamber 3 into the oil chamber 5 can be further suppressed.

In this embodiment, as described above, the opening area of the suction port 7 is larger than the area of the cross section of the rotating shaft 2 orthogonal to the axial direction. As a result, a relatively large opening area of the suction port 7 can be ensured, so that the liquid can flow into the pump chamber 3 effectively.

In this embodiment, as described above, the opening area of the suction port 7 is approximately the same size as the area of the inner region of the inner diameter of the end portion 42a of the blade portion 42 on the side of the suction port 7 . As a result, an amount of liquid suitable for the specifications of the impeller 4 can be made to flow from the suction port 7 .

In this embodiment, as described above, the discharge port 8 for discharging liquid from the pump chamber 3 is further provided, and the suction port 7 and the discharge port 8 are arranged on one side and the other side of the rotating shaft 2, respectively. . As a result, compared to the case where the suction port 7 and the discharge port 8 are arranged on the same side of the rotating shaft 2 , the suction port 7 , the impeller 4 , and the discharge port 8 are arranged in the axial direction of the rotating shaft 2 . It is possible to suppress a large change in the direction of the sequentially flowing liquid. That is, the liquid can flow efficiently in the pump chamber 3 .

(Modification)
It should be noted that the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the meaning and scope equivalent to the scope of the claims.

For example, in the above embodiment, an example in which the shape of the suction port is circular was shown, but the present invention is not limited to this. In the present invention, the shape of the suction port may be a shape other than circular, such as a rectangular shape.

Moreover, in the above-described embodiment, an example is shown in which the discharge port and the suction port are configured so as not to overlap each other in the axial direction of the rotating shaft, but the present invention is not limited to this. In the present invention, the discharge port and the suction port may overlap each other.

In addition, in the above-described embodiment, the center line (not shown) of the suction port and the discharge port is arranged substantially on the same straight line in a plan view (as seen from the Z direction). is not limited to this. In the present invention, they may be arranged on different straight lines in plan view (as seen from the Z direction). Therefore, for example, in a plan view (as seen from the Z direction), the suction port and the discharge port may be arranged so as to overlap.

Further, the opening area of the suction port is not limited to that described in the above embodiment.

Further, in the above-described embodiment, an example in which the present invention is applied to a vertical submersible pump arranged so that the rotating shaft extends in the vertical direction was shown, but the present invention is not limited to this. The present invention may be applied to a horizontal submersible electric pump arranged so that the rotating shaft extends horizontally. In this case, it is preferable to arrange the suction port on the lower side.

REFERENCE SIGNS LIST 1 motor 2 rotating shaft 3 pump chamber 4 impeller 5 oil chamber 6 mechanical seal 6a, 6b sliding portion 7 suction port 8 discharge port 41 base 42 blade portion 42a end portion (on the suction port side of the blade portion) 100 submersible pump

Claims (7)

a motor;
a suction port that allows liquid to flow into the pump chamber;
an impeller disposed in the pump chamber, including a base attached to a rotating shaft that is rotationally driven by the motor; and a blade portion provided on the suction port side of the base in the axial direction of the rotating shaft; ,
a mechanical seal including a sliding portion that slides with rotation of the rotating shaft and disposed in an oil chamber between the pump chamber and the motor;
a rib portion having a constant width in the axial direction and forming a suction passage extending linearly from the suction port to an end portion on the rotating shaft side in a direction orthogonal to the axial direction ;
The suction port is configured to allow liquid to flow into the pump chamber from a direction intersecting the axial direction, and is arranged at a position closer to the mechanical seal than the impeller in the axial direction ,
In the axial direction, the upper end of the suction port is arranged below the lower end of the mechanical seal,
The submersible pump , wherein, in a direction orthogonal to the axial direction, the end of the rib portion on the rotating shaft side is arranged closer to the suction port than the end of the blade portion on the rotating shaft side . 2. The submersible pump according to claim 1, wherein a portion of said pump chamber on the oil chamber side is configured to have a negative pressure due to rotation of said impeller. further comprising a discharge port for discharging liquid from the pump chamber,
3. The submersible pump according to claim 1, wherein said suction port is arranged at a position not overlapping with said discharge port in said axial direction. 4. The submersible pump according to claim 3, wherein said suction port is arranged at a position closer to said mechanical seal than said discharge port in said axial direction. The submersible pump according to any one of claims 1 to 4, wherein the opening area of the suction port is larger than the area of the cross section of the rotating shaft perpendicular to the axial direction. The submersible pump according to any one of claims 1 to 5, wherein the opening area of the suction port is approximately the same size as the area of the inner diameter of the end portion of the blade portion on the suction port side. further comprising a discharge port for discharging liquid from the pump chamber,
The submersible pump according to any one of claims 1 to 6, wherein the suction port and the discharge port are arranged on one side and the other side of the rotating shaft, respectively.

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