JP5767911B2 - Impeller and submersible pump - Google Patents

Description

  The present invention relates to an impeller for feeding sewage and the like and a submersible pump using the impeller.

  As a submersible pump used for water supply such as dirty water, a spiral pump in which an impeller is accommodated in a spiral casing is used. A submersible pump is known in which an impeller rotates to discharge dirty water sucked from a suction port provided on a lower surface of a casing from a discharge port provided on a side surface of the casing.

  Such submersible pumps used for water supply such as sewage reliably prevent filth contained in sewage in order to prevent malfunctions caused by foreign matter contained in sewage being caught in a rotating shaft or impeller. A configuration that can be discharged is required.

  For this reason, for example, an impeller having a plurality of blades called so-called semi-open blades provided on one shroud is used. However, since such an impeller is poor in pump efficiency, when high efficiency is required, an impeller using blades called so-called closed blades is also known (for example, Patent Document 1).

  An impeller using closed blades has a configuration in which blades are provided between two shrouds, and there is a higher risk of foreign matter being caught in the impeller than an impeller using semi-open blades. For this reason, an impeller having a single blade between shrouds as a closed blade is also known in order to prevent foreign substances from being caught.

  As for the impeller of one blade, in order to improve pump efficiency, a technique for increasing the thickness of the blade is known. Specifically, the impeller of a single blade has a configuration in which the thickness of the blade is different at one end side, the central side, and the other end side, for example, gradually from one end side located at the center side of the impeller toward the central side. The thickness increases, and the thickness gradually decreases from the center side toward the other end side located on the outer peripheral side of the impeller.

  Such a single-blade impeller has a configuration in which only one blade is provided between the shrouds, and the thickness of the blade is different. Therefore, the mechanical balance such as arrangement and weight is poor, and vibration and noise are not generated. There is a risk of an increase.

  For this reason, when a submersible pump is arranged, a technology that improves the mechanical balance by providing a recess that hollows the inside of the blade from the shroud located on the upper side and reducing the difference in weight with other parts as much as possible It has been known.

  However, if the impeller is provided with a recess, foreign matter or the like in the sewage is accumulated in the recess, causing vibration and noise. In addition, the concave portion causes an increase in fluid resistance when the impeller rotates, and there is a problem that the shaft power of the submersible pump increases.

  Therefore, a technique is also known in which the upper surface of the shroud including the recess is covered with a lid and a discharge port for intruders in the recess is provided to prevent generation of vibration and noise (see, for example, Patent Document 2).

JP 2002-202092 A JP 2006-90279 A

  The above-described impeller and submersible pump have the following problems. That is, in an impeller in which a single blade is provided with a concave portion and a concave portion is provided with a lid, a lid is necessary, which increases the manufacturing cost. In particular, as the outer diameter of the impeller increases, the outer diameter of the lid also increases, so that the manufacturing cost also increases.

  In order to increase the passage diameter of foreign matter or the like, it is desirable that the outlet width of the impeller and the discharge port diameter of the pump be the same. However, in such an impeller, since the pair of shrouds and the impeller are manufactured by casting or the like, the outlet width is slightly larger than the discharge diameter in order to ensure a predetermined foreign substance passage diameter. It was. For this reason, the exit width becomes larger than the target dimension, and there is a possibility that the performance is deteriorated.

  In view of the above, an object of the present invention is to provide an impeller and a submersible pump that can ensure a predetermined foreign substance passage diameter, prevent performance degradation, and reduce manufacturing costs.

  In order to solve the problems and achieve the object, the impeller and the submersible pump of the present invention are configured as follows.

  As one aspect of the present invention, an impeller that is housed in a casing of a submersible pump and rotates by a rotating shaft to pump fluid is provided with a first shroud and a second shroud provided opposite to the first shroud. The shroud is integrally formed with one of the first shroud and the second shroud and is fixed to the other of the first shroud and the second shroud, and the other of the first shroud and the second shroud. And a single blade that is continuous from the center side to the outer periphery side of the first shroud and the second shroud.

  As one aspect of the present invention, a submersible pump includes a motor, a rotating shaft connected to the motor, a first shroud, a second shroud provided to face the first shroud, and the first shroud and A main surface formed integrally with one of the second shrouds and fixed to the other of the first shroud and the second shroud and fixed to the other of the first shroud and the second shroud is an opening. An impeller including a single blade that is continuous from the center side to the outer peripheral side of the first shroud and the second shroud, and a pump casing that houses the impeller. .

  According to the present invention, it is possible to provide an impeller and a submersible pump that can ensure a predetermined foreign substance passage diameter and prevent performance degradation, and can reduce manufacturing costs.

Explanatory drawing which shows the structure of the submersible pump which concerns on one embodiment of this invention in a cross section. The top view which shows the structure of the impeller used for the submersible pump.

Hereinafter, the submersible pump 1 which concerns on one embodiment of this invention is demonstrated using FIG.1 and FIG.2.
FIG. 1 is a cross-sectional view illustrating the configuration of a submersible pump 1 according to an embodiment of the present invention, and FIG. 2 is a top view illustrating the configuration of an impeller 42 used in the submersible pump 1. In FIG. 1, B represents a bolt, F represents a water flow, K represents a power cable, and L represents a liner ring.

  As shown in FIG. 1, the submersible pump 1 includes a motor 10, a shaft seal device 11, and a pump 12. Such a submersible pump 1 is a so-called submersible sewage pump that is installed in a sewage tank, a sewer, or the like and feeds sewage containing foreign matter (sewage etc.).

  The motor 10 includes a motor casing 21, a stator 22, a rotor 23, and a rotating shaft 24. The motor 10 also has a power cable K connected to an external power source or the like. The motor casing 21 is formed in a cylindrical shape in which both ends are closed, and one end surface is fixed to the shaft seal device 11 with a bolt B or the like.

  The stator 22 is fixed to the inner surface of the motor casing 21. The stator 22 is formed so that the rotor 23 can be rotated by electric power supplied via the power cable K. The rotor 23 is fixed to the rotating shaft 24 so as to be able to rotate the rotating shaft 24 following the rotation.

  The rotating shaft 24 protrudes from one end side of the motor casing 21 and is rotatably supported by the motor casing 21 via a bearing 25 such as a bearing. The rotating shaft 24 extends from the motor casing 21 in the direction of gravity.

  The shaft seal device 11 includes a seal casing 30 and a mechanical seal 31. The shaft seal device 11 partitions the motor 10, the pump 12, and the rotary shaft 24 in a liquid-tight manner.

  The seal casing 30 is formed so that a mechanical seal 31 can be accommodated therein. Such a seal casing 30 is formed in a cylindrical shape whose both ends are closed, and is provided with insertion holes 33 through which the rotary shaft 24 is inserted. Moreover, the seal casing 30 forms an oil chamber 34 in which the lubricating oil of the mechanical seal 31 can be filled.

  The mechanical seal 31 is formed so as to prevent infiltration of sewage from the pump 12 and ingress of lubricating oil into the motor 10 by sealing between the seal casing 30 and the rotary shaft 24. As described above, the shaft seal device 11 employs a so-called two-stage structure that prevents foreign matter from entering the motor 10 by providing the mechanical seal 31 in the seal casing 30 filled with lubricating oil.

  The pump 12 includes a casing 41 and an impeller 42. The casing 41 is a spiral casing that houses the impeller 42 therein, and forms a pump chamber 43 therein. The casing 41 has an upper member 44 and a lower member 45 that form a pump chamber 43 by being assembled, and is formed so as to be disassembleable with the impeller 42 fixed to the rotary shaft 24.

  In this embodiment, the upper member 44 is formed integrally with a part of the seal casing 30. The upper member 44 has a first support portion 47 that instructs the impeller 42 to be rotatable below the insertion hole 33 described above.

  The lower member 45 includes a plurality of legs 48 for installing the submersible pump 1 on the installation surface. The lower member 45 includes a suction opening 49 provided between the plurality of leg portions 48 on the bottom surface thereof, and a discharge opening 50 provided on the side surface thereof.

  In addition, the discharge opening 50 is formed so that the diameter (discharge diameter) can pass the foreign material of the particle size which can pass the impeller 42. FIG. Specifically, the diameter of the discharge opening 50 is substantially the same as a foreign substance having a predetermined particle diameter that can pass through the impeller 42 and is substantially the same as the opening width of a discharge opening 63 of the impeller 42 described later. Is formed. Here, the foreign substance having a predetermined particle diameter that can pass through the impeller 42 is a spherical solid having the same diameter (predetermined particle diameter) as the diameter (discharge diameter) of the discharge opening 50 of the submersible pump 1.

  The suction opening 49 is formed to have substantially the same diameter as a suction port 58 described later of the impeller 42. The suction opening 49 has the 2nd support part 49a which supports the impeller 42 so that rotation is possible. The insertion hole 33, the first support portion 47, and the second support portion 49a are provided with a liner ring L that can slide with the rotary shaft 24 and the impeller 42. The first support portion 47 and the second support portion 49a are formed by the inner surfaces of these liner rings L.

  The impeller 42 is a non-clog closed impeller, and is formed so as to allow passage of a foreign substance having a predetermined particle diameter. Such an impeller 42 includes an upper shroud (first shroud) 52 disposed on the shaft seal device 11 side, a lower shroud (second shroud) 53 disposed on the suction opening 49 side, and the shrouds 52, 53. And a blade 54 provided therebetween. The impeller 42 has a suction port 58 for sucking fluid provided in the lower shroud 53, and a discharge port 63 formed by the upper shroud 52, the lower shroud 53, and the blades 54 for discharging the sucked fluid. .

  The upper shroud 52 is formed in a disk shape. The upper shroud 52 is formed with a first supported portion 57 in which the rotation shaft 24 can be inserted and an insertion hole 56 having a key groove 56a is formed. The upper shroud 52 is located above the lower shroud 53 with respect to the direction of gravity when the impeller 42 is fixed to the rotating shaft 24.

  The lower shroud 53 is formed in an annular shape. The lower shroud 53 has a suction port 58 formed in the center thereof. Moreover, the center side of the lower shroud 53 protrudes in an annular shape, and a second supported portion 59 is formed on the outer peripheral side of the protrusion.

  The first supported portion 57 is supported by the first support portion 47 via the liner ring L so as to be rotatable and slidable. The second supported portion 59 is supported by the second support portion 49a via the liner ring L so as to be rotatable and slidable.

  One blade 54 is provided between the upper and lower shrouds 52 and 53. Specifically, the blades 54 are formed integrally with the lower shroud 53 and are fixed to the upper shroud 52 by fastening with bolts or welding.

  As shown in FIG. 2, one end of the blade 54 is disposed on the center side of the shrouds 52 and 53, and the other end is disposed on the outer peripheral edge of the shrouds 52 and 53. The blade 54 is formed in a shape in which the diameter from the center of the shrouds 52 and 53 (the rotation center of the impeller 54) is different at each position, for example, a spiral shape or an involute shape. The detailed shape can be set as appropriate as long as the impeller 42 is capable of pumping (transferring) sewage with a predetermined pump efficiency.

  The blades 54 are thin at both ends, and gradually increase in thickness toward the center. The blade 54 has a concave portion 55 that forms a hollow inside. The concave portion 55 is a concave portion that is recessed along the outer shape of the blade 54 provided on the main surface to which the upper shroud 52 is fixed, and is closed by the upper shroud 52.

  The blade 54 pumps the sewage sucked from the suction port 58 of the shroud 53 between the shrouds 52 and 53 and the end portions, and between the end portion and the middle portion located on the outer peripheral side of the shrouds 52 and 53. A discharge port 63 to be moved into the chamber 43 is formed.

  The discharge port 63 is an opening for discharging the sewage sucked from the suction port 58 to the pump chamber 43. The discharge port 63 is formed so as to be able to discharge a foreign particle having a predetermined particle size, that is, a maximum particle size of foreign particles that can pass through the impeller 42.

  Next, a method for manufacturing such an impeller 42 will be described. First, the upper shroud 52 and the integrated lower shroud 53 and blades 54 are respectively formed by casting. At this time, the blades 54 are formed to have a height equal to or greater than the opening width between the predetermined upper and lower shrouds 52 and 53 of the discharge port 63 of the impeller 42.

  Next, the height of the blades 54 is processed to be the same as the target (predetermined) height dimension (opening width) of the discharge port 63. In addition, when the height of the molded blade | wing 54 is the same as the said opening width | variety, a process is unnecessary. However, when the flatness of the surface that contacts the upper shroud 52 of the blade 54 is poor or the surface roughness is low, additional processing may be performed.

  Next, the upper shroud 52 is fixed on the blades 54. For example, in the fixing, the upper surface of the blade 54 and the lower surface of the upper shroud 52 are joined by welding. Thereby, the impeller 42 is formed.

  The submersible pump 1 configured as described above is supplied with electric power through the power cable K, whereby the motor 10 is driven, and the rotor 23 is rotated by the stator 22, whereby the rotary shaft 24 rotates. As the rotor 23 rotates, the impeller 42 also rotates.

  As shown in the water flow F in FIG. 1, due to the rotation of the impeller 42, the sewage sucked from the suction port 58 is increased in pressure by the casing 41 and the impeller 42 and discharged from the discharge port 63. By these things, submersible pump 1 is constituted so that dirty water can be sent to the secondary side.

  According to the submersible pump 1 configured as described above, by providing the blade 54 with the concave portion 55 that is a hollow portion, it is possible to reduce the uneven weight balance due to the blade 54 as much as possible. This makes it possible to improve the mechanical balance such as arrangement and weight, and to prevent vibration and noise during rotation as much as possible.

  Further, by welding the upper shroud 52 to the blades 54, it becomes possible to prevent sewage from entering the recess 55, and it is possible to prevent an increase in weight due to sewage. Since the blades 54 have the recesses 55, the weight thereof is reduced. As a result, the weight of the impeller 42 is reduced, the load applied in the thrust direction can be reduced, and the thrust life is improved. Moreover, the weight of the submersible pump 1 is reduced.

  Further, the impeller 42 only needs to fix the upper shroud 52 to the blades 54, and does not increase the manufacturing process. For this reason, it becomes possible to reduce manufacturing cost compared with the technique which obstruct | occludes the recessed part 55 with the cover body etc. of the prior art.

  Furthermore, since the impeller 42 is configured to fix the separate upper shroud 52 after the lower shroud 53 and the blade 54 are integrally formed by casting, the opening width of the discharge port 63 of the impeller 42, that is, the blade 54. It is possible to process the height after casting by manufacturing. Thereby, even if the height of the blades 54 formed by casting varies, the dimensional accuracy of the height of the blades 54 can be improved in accordance with the predetermined opening width of the discharge port 63. In addition, by setting the discharge port 63 to a predetermined opening width (target dimension), it is possible to reliably prevent a decrease in performance while ensuring a predetermined foreign substance passage diameter. Thereby, the dispersion | variation in the pump performance of the submersible pump 1 is prevented, and it becomes possible to improve reliability.

  As described above, according to the submersible pump 1 according to the present embodiment, the upper shroud 52 can be fixed to the blades 54 even if the lower shroud 53 and the blades 54 having the recessed portions 55 for weight reduction are integrally molded. Thus, variation in the size of the exit width of the impeller 42 can be prevented, and the manufacturing cost can be reduced. In addition, the submersible pump 1 can set the height of the blade 54 (discharge port 63) to a target size by processing the height of the blade 54, and can ensure a predetermined foreign substance passage diameter and prevent deterioration in performance. It becomes possible to do.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the configuration in which the upper surface of the blade 54 and the lower surface of the upper shroud 52 are joined by welding as a method of fixing the upper shroud 52 on the blade 54 is not limited to this. For example, the impeller 42 may be configured by providing a female screw hole in the blade 54, providing a bolt hole in the upper shroud 52, and connecting the upper shroud 52 to the blade 54 with a fastening member such as a bolt. In addition, when the upper shroud 52 and the blades 54 are combined with the fastening member in this way, foreign matter can be prevented from entering the recess 55, but there is a possibility that filthy water may enter. Such a sealing member may be interposed between the upper shroud 52 and the blades 54.

  In the above-described example, the configuration in which the blades 54 and the lower shroud 53 are integrally molded by casting has been described, but the present invention is not limited to this. For example, the configuration may be such that the upper shroud 52 and the blades 54 are integrally molded, the opening of the recess 55 is provided on the surface facing the lower shroud 53, and the blades 54 and the lower shroud 53 are fixed. In addition, various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Submersible pump, 10 ... Motor, 11 ... Shaft seal device, 12 ... Pump, 21 ... Motor casing, 22 ... Stator, 23 ... Rotor, 24 ... Rotary shaft, 25 ... Bearing, 30 ... Seal casing, 31 ... Mechanical seal, 33 ... insertion hole, 34 ... oil chamber, 41 ... casing, 42 ... impeller, 43 ... pump chamber, 44 ... upper member, 45 ... lower member, 47 ... support part, 48 ... leg part, 49 ... suction Opening, 49a ... support part, 50 ... discharge opening, 52 ... upper shroud (first shroud), 53 ... lower shroud (second shroud), 54 ... vanes, 55 ... recess, 56a ... keyway, 56 ... insertion hole, 57 ... Supported portion, 58 ... Suction port, 59 ... Supported portion, 63 ... Discharge port, B ... Bolt, K ... Power cable, L ... Liner ring.

Claims (6)

An impeller that is housed in a casing of a submersible pump and rotates by a rotating shaft to pump fluid.
A first shroud;
A second shroud provided opposite the first shroud;
Molded integrally with one of the first shroud and the second shroud, and fixed to the other of the first shroud and the second shroud, and fixed to the other of the first shroud and the second shroud. A single blade that is formed from a center side to an outer peripheral side of the first shroud and the second shroud, in which a hollow recess having an open main surface is formed;
An impeller comprising: The blade is integrally formed with one of the first shroud and the second shroud by casting, and is joined to the other of the first shroud and the second shroud by welding. Item 1. The impeller according to Item 1.   The blade is integrally formed with one of the first shroud and the second shroud by casting, and is coupled to the other of the first shroud and the second shroud by a fastening member. The impeller according to claim 1. A motor,
A rotating shaft connected to the motor;
A first shroud, a second shroud provided opposite to the first shroud, and one of the first shroud and the second shroud; and the first shroud and the second shroud An outer peripheral side from the center side of the first shroud and the second shroud, which is fixed to the other and formed with a hollow recess in which a main surface fixed to the other of the first shroud and the second shroud opens. An impeller having a single continuous blade,
A pump casing that houses the impeller;
A submersible pump characterized by comprising: The blade is integrally formed with one of the first shroud and the second shroud by casting, and is joined to the other of the first shroud and the second shroud by welding. Item 5. The impeller according to Item 4.   The blade is integrally formed with one of the first shroud and the second shroud by casting, and is coupled to the other of the first shroud and the second shroud by a fastening member. The impeller according to claim 4.

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