Pump device

Abstract

To provide a pump device capable of preventing deterioration of mounting strength even when correcting weight imbalance.SOLUTION: A pump device 1 comprises: a pump 12 having an impeller 30 having a rear shroud 31, a front shroud 32 facing the rear shroud 31, a plurality of blades 33 arranged between the rear shroud 31 and the front shroud 32, and a balance adjustment unit 30a formed by cutting outer circumferential edges of the rear shroud 31 and the front shroud 32 between adjacent blades 33; and a motor 11 that drives the pump 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pump apparatus having an impeller with a shroud. [Background technology]

[0002] A pump has a technique for pumping water as a fluid to a secondary side by using one or more impellers. For example, the impeller has a pair of shrouds, and a plurality of blades are fixed to the pair of shrouds by welding or the like.

[0003] In such pumps, if the weight balance of the impeller is unbalanced, abnormal vibrations will occur, and therefore there is a demand for technology to correct the amount of imbalance in the impeller.

[0004] As a method for correcting the weight imbalance of a turbocharger impeller, a technique for performing cutting on the back surface of the impeller is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 04-142432 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology of Patent Document 1 described above, the weight imbalance is corrected by cutting the boss of the impeller, but a predetermined range is cut in the circumferential direction on the outer edge of the boss and on the back plate side of the impeller that is continuous with the boss. However, in cases where the blades are fixed to the boss, the area where the blades are to be provided is also cut, and in the case of an impeller configured such that the blades are fixed to the boss, there is a risk that the mounting strength of the blades may decrease.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a pump device capable of preventing a decrease in mounting strength even when the weight imbalance is corrected. [Means for solving the problem]

[0008] According to one aspect of the present invention, a pump device includes a pump equipped with an impeller having a rear shroud, a front shroud facing the rear shroud, a plurality of blades arranged between the rear shroud and the front shroud, and a balance adjustment portion formed by cutting the outer peripheral edges of the rear shroud and the front shroud between adjacent blades, and a motor that drives the pump. Effect of the Invention

[0009] According to the present invention, it is possible to provide a pump device capable of preventing a decrease in mounting strength even when the weight imbalance is corrected. [Brief description of the drawings]

[0010] [Figure 1] 1 is a side view, partially in cross section, showing a configuration of a pump device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing the configuration of an impeller used in the pump device. [Diagram 3] FIG. [Figure 4] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An impeller 30 according to one embodiment of the present invention and a pump device 1 using the impeller 30 will be described below with reference to Fig. 1 to Fig. 4. Fig. 1 is a side view showing, in partial cross section, the configuration of the pump device 1 according to one embodiment of the present invention, Fig. 2 is a perspective view showing the configuration of the impeller 30 used in the pump device 1, Fig. 3 is a plan view showing the configuration of the impeller 30, and Fig. 4 is a cross-sectional view showing the configuration of the impeller 30. Note that, for the purpose of explanation, the configuration is omitted or enlarged or reduced in each figure as appropriate.

[0012] As shown in Fig. 1, the pump device 1 is, for example, a turbine pump. The pump device 1 includes a motor 11 and a single-stage or multi-stage pump 12. In the example shown in Fig. 1, the pump device 1 is a multi-stage pump having three impellers 30, which will be described later. For example, the pump device 1 is connected to a control panel that houses an inverter and multiple control boards. The pump device 1 also includes a base 13 that supports the motor 11 and the pump 12.

[0013] The motor 11 is connected to the pump 12 and drives the pump 12. The motor 11 is connected to a control panel by a cable. The motor 11 is connected to a control board via multiple inverters, and the rotation speed of the motor 11 is controlled by a control unit mounted on the control board.

[0014] The pump 12 includes a rotating shaft 21 , a pump casing 22 , a casing cover 23 , a bearing member 24 , and one or more impellers 30 housed in the pump casing 22 and fixed to the rotating shaft 21 .

[0015] The rotating shaft 21 is connected to the motor 11. The rotating shaft 21 may be connected to the motor shaft of the motor 11 via a shaft coupling, or may be fixed to the rotor of the motor 11 and serve as the motor shaft as well. The rotating shaft 21 is configured to be able to fix the impeller 30 of the pump 12. The rotating shaft 21 is journaled by a bearing member.

[0016] The pump casing 22 has a pump suction port and a pump discharge port, and houses a plurality of impellers 30. The pump casing 22 is made of, for example, stainless steel, and includes a suction section 22a facing the tip of the rotating shaft 21, a housing section 22b provided continuously with the suction section 22a, and a cylindrical discharge section 22c provided on a part of the outer circumferential surface of the pump casing 22, for example, on the upper part of the pump casing 22, communicating with the outer periphery of the housing section 22b. The pump casing 22 also has, for example, a plurality of inner casings 22d provided in the housing section 22b and housing each of the impellers 30. The motor 11 side of the pump casing 22 is open so that the inner casings 22d and the impellers 30 can be placed in the housing section 22b.

[0017] The casing cover 23 is fixed to the pump casing 22 and the motor casing 11a of the motor 11. The casing cover 23 closes the opening of the pump casing 22 on the motor 11 side.

[0018] The impeller 30 is a closed type impeller, for example, a pressed impeller. The impeller 30 includes a rear shroud 31, a front shroud 32 disposed opposite the rear shroud 31, a plurality of blades 33 disposed between the rear shroud 31 and the front shroud 32 and disposed at equal intervals in the circumferential direction of the impeller 30, and an impeller hub 34 provided in the center of the rear shroud 31. The impeller 30 also includes balance adjustment portions 30a on parts of the outer circumferential edges of the rear shroud 31 and the front shroud 32.

[0019] The balance adjustment portion 30a is formed by cutting a part of the outer circumferential edge of the rear shroud 31 and the front shroud 32 in a straight line at the same position in the circumferential direction. The balance adjustment portion 30a is formed, for example, by cutting the rear shroud 31 and the front shroud 32 in the same shape. The balance adjustment portion 30a is formed, for example, as shown in Figs. 2 and 3, between the blades 33 adjacent in the circumferential direction of the outer circumferential edges of the rear shroud 31 and the front shroud 32, and is preferably formed avoiding the area where the blades 33 are joined. As a preferred example, for example, as shown in Figs. 2 and 3, the balance adjustment portion 30a is a notch formed in a straight line along the tangential direction of the outer circumferential edges of the rear shroud 31 and the front shroud 32 and between the adjacent blades 33. The balance adjustment portion 30a is formed, for example, at one or more points on the outer circumferential edge of the impeller 30 (the rear shroud 31 and the front shroud 32). 2 and 3 show an example of the impeller 30 in which the balance adjustment portion 30a is formed at one location.

[0020] The back shroud 31 is configured in a disk shape. The back shroud 31 extends in a direction perpendicular to the axis that is the rotation center of the impeller 30, and is formed in the shape of an annular plate with an opening 31a formed in the center.

[0021] The front shroud 32 is disposed opposite the rear shroud 31 with a predetermined gap therebetween. The front shroud 32 has a circular outer shape in a plan view in the axial direction. The front shroud 32 has a cylindrical suction port 32a that forms a circular opening at the center for sucking in a fluid. The outer peripheral surface of the suction port 32a of the front shroud 32 is rotatably supported by, for example, the pump casing 22 or the inner casing 22d via a liner ring. Note that the outer peripheral surface of the suction port 32a of the front shroud 32 may be configured to face, for example, the pump casing 22 or the inner casing 22d with a predetermined gap therebetween.

[0022] The front shroud 32 is formed in a plate shape extending in a direction intersecting the axis of the impeller 30 so that the gap between the front shroud 32 and the rear shroud 31 in the axial direction of the impeller 30 gradually increases from the outer circumferential edge side toward the center side. The suction port 32a is formed in a cylindrical shape extending in the axial direction of the impeller 30 on the center side of the front shroud 32.

[0023] A plurality of blades 33 are provided between the rear shroud 31 and the front shroud 32 and arranged at equal intervals in the circumferential direction of the impeller 30. The blades 33 are joined to the rear shroud 31 and the front shroud 32 by, for example, laser welding. The blades 33 are curved with, for example, a predetermined radius of curvature. The interval between adjacent blades 33 in the circumferential direction of the impeller 30 gradually increases from the center side of the impeller 30 toward the outer circumferential edge side.

[0024] The impeller hub 34 is formed in a cylindrical shape with an outer diameter that varies in parts, and is provided at the center of the rear shroud 31. The impeller hub 34 is joined to the rear shroud 31 by welding such as laser welding. The impeller hub 34 includes, for example, a seat portion 34a that comes into contact with the rear shroud 31 when inserted into the opening 31a of the rear shroud 31, a hole portion 34b into which the rotating shaft 21 is inserted, and a cylindrical boss portion 34c that protrudes from the rear shroud 31 toward the suction port 32a of the front shroud 32. The impeller hub 34 is inserted into the opening 31a of the rear shroud 31, and joined to the rear shroud 31 with the seat portion 34a coming into contact with the rear shroud 31. The boss portion 34c is formed in a cylindrical shape with an outer diameter that decreases from the rear shroud 31 toward the front shroud 32 side and has a constant outer diameter at the tip.

[0025] Such an impeller 30 is formed by pressing a metal plate such as a steel plate to form a rear shroud 31 serving as a main plate, a front shroud 32 serving as a side plate, and a plurality of blades 33, and by integrally joining the formed rear shroud 31, front shroud 32, and a plurality of blades 33 by laser welding or the like. Note that the impeller hub 34 may be joined simultaneously with the joining of the rear shroud 31, front shroud 32, and a plurality of blades 33, or may be joined after the joining of the rear shroud 31, front shroud 32, and a plurality of blades 33, or may be joined to the rear shroud 31 in advance before the joining of the rear shroud 31, front shroud 32, and a plurality of blades 33.

[0026] The weight balance of the impeller 30 to which the rear shroud 31, the front shroud 32, and the plurality of blades 33 are welded is measured by a measuring device, and if the weight balance is unbalanced, a balance correction is performed. The balance correction is performed by cutting the outer peripheries of the rear shroud 31 and the front shroud 32 linearly along the tangential direction with a disc grinder or the like to adjust the weight balance of the impeller 30. Here, the rear shroud 31 and the front shroud 32 are cut into the same shape as the balance correction. That is, the balance adjustment portion 30a is a portion where the outer peripheries of the rear shroud 31 and the front shroud 32 of the impeller 30 are cut into the same shape as the balance correction. Note that FIG. 3 shows the formed balance adjustment portion 30a, and the state before the formation of the balance adjustment portion 30a is shown by a two-dot chain line for reference.

[0027] Furthermore, for example, after the balance adjustment portion 30a is formed, the weight balance of the impeller 30 is measured again by a measuring device, and if the weight balance is unbalanced, the balance adjustment portion 30a is formed by cutting at a predetermined position as a balance correction. Note that the position where the balance adjustment portion 30a is formed and the amount of cutting are determined depending on the amount of unbalance. For example, the balance correction is performed by repeatedly forming the balance adjustment portion 30a on the impeller 30 and adjusting the balance until the weight balance of the impeller 30 reaches a predetermined value.

[0028] The impeller 30 configured in this manner has a balance adjustment portion 30a formed by cutting the rear shroud 31 and the front shroud 32 at its outer peripheral edge, so that the weight balance is adjusted, thereby making it possible to reduce vibration when the pump 12 is operating.

[0029] In addition, the balance adjustment portion 30a is formed between the adjacent blades 33 on the outer peripheries of the rear shroud 31 and the front shroud 32. This prevents the balance adjustment portion 30a from being provided at the welded portion of the rear shroud 31, the front shroud 32, and the blades 33. This prevents the impeller 30 from reducing the welding strength, which is the attachment strength of the rear shroud 31, the front shroud 32, and the multiple blades 33, due to the balance adjustment portion 30a. In this way, the impeller 30 can be corrected for balance while maintaining the welding strength. In addition, the balance adjustment portion 30a is formed on the outer peripheries of the rear shroud 31 and the front shroud 32 between the adjacent blades 33, i.e., the blades 33 can be prevented from being cut, so that the function of some of the multiple blades 33 is not reduced.

[0030] In addition, since the balance adjustment portion 30a is formed by cutting the outer peripheral edges of the rear shroud 31 and the front shroud 32, balance correction can be performed regardless of the size of the outer diameter of the impeller 30.

[0031] In addition, since the balance adjustment portion 30a is formed linearly on the outer circumferential edges of the rear shroud 31 and the front shroud 32, the balance adjustment portion 30a can be formed by cutting using a disk grinder or the like, eliminating the need for new capital investment. Since the balance adjustment portion 30a is configured to cut both the rear shroud 31 and the front shroud 32, it can be processed more easily than cutting one of the rear shroud 31 and the front shroud 32.

[0032] As described above, according to the impeller 30 and pump device 1 of one embodiment of the present invention, by forming the balance adjustment portion 30a on the outer peripheral edges of the rear shroud 31 and the front shroud 32 between adjacent blades 33, even if the weight imbalance of the impeller 30 is corrected, it is possible to prevent a decrease in the welding strength of the rear shroud 31, the front shroud 32 and the multiple blades 33.

[0033] In the above example, the impeller 30 is an example of a pressed impeller, but the present invention is not limited to this, and may be formed by, for example, resin molding or casting.

[0034] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0035] 1...pump device, 11...motor, 11a...motor casing, 12...pump, 13...base, 21...rotating shaft, 22...pump casing, 22a...suction portion, 22b...accommodation portion, 22c...discharge portion, 22d...inner casing, 23...casing cover, 24...bearing member, 30...impeller, 30a...balance adjustment portion, 31...rear shroud, 31a...opening, 32...front shroud, 32a...suction port, 33...blade, 34...impeller hub, 34a...seat portion, 34b...hole portion, 34c...boss portion.

Claims

1. a pump including an impeller having a rear shroud, a front shroud facing the rear shroud, a plurality of blades disposed between the rear shroud and the front shroud, and a balance adjustment portion formed by cutting an outer circumferential edge of the rear shroud and the front shroud between adjacent blades; A motor that drives the pump; A pump device comprising:

2. The pump device according to claim 1 , wherein the balance adjustment portion is formed in a straight line.

3. The pump apparatus according to claim 2 , wherein the balance adjustment portion extends along a tangential direction of outer circumferential edges of the rear shroud and the front shroud.

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