Pump casing and pump device

Abstract

To provide a pump casing capable of easily washing an inner channel with a simple structure.SOLUTION: A pump casing 5 is equipped with a suction nozzle 100 formed with a suction port 12. The suction nozzle 100 inclines downward toward the suction port 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pump casing and a pump device.

Background Art

[0002] A pump device including a rotating shaft, an impeller fixed to the rotating shaft, a motor that rotates the impeller together with the rotating shaft, and a pump casing that houses the impeller and has a suction port and a discharge port is known (see, for example, Patent Document 1).

[0003] When the motor is driven, the rotating shaft and the impeller rotate. When the impeller rotates, the liquid flows into the pump casing through the suction port and is pressurized as the impeller rotates. The pressurized liquid is discharged from the discharge port.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Depending on the intended use, the pump device is periodically disassembled and cleaned to maintain the quality of the conveyed liquid. When removing the pump from the piping and cleaning the inside of the pump casing, it is necessary to completely remove the liquid so that no liquid remains inside the pump casing. In addition, there is a concern that when moving the removed pump, the surrounding area may be soiled by the liquid remaining inside the pump casing.

[0006] Therefore, an object of the present invention is to provide a pump casing having a simple structure and capable of easily cleaning the internal flow path, and a pump device including this pump casing.

Means for Solving the Problem

[0007] In one aspect, a pump casing having a suction port connected to a suction pipe extending in the horizontal direction is provided. The pump casing includes a suction nozzle in which the suction port is formed, and the suction nozzle is inclined downward toward the suction port.

[0008] In one aspect, the suction port is the lowest bottom part within the pump casing. In one aspect, the pump casing includes a volute part to which the suction nozzle is connected, and the suction nozzle has a linear shape extending obliquely downward from the volute part. In one aspect, the suction port is disposed below the volute part, and a working space for connecting the suction nozzle to the suction pipe is formed between the volute part and the suction nozzle.

[0009] In one aspect, a pump casing having a suction port and a discharge port is provided. The pump casing includes a suction nozzle in which the suction port is formed, and the suction nozzle has a drain port at its lowermost part.

[0010] In one aspect, a pump device is provided, which includes an impeller, a rotating shaft to which the impeller is fixed, a motor for rotating the rotating shaft, and the above-mentioned pump casing for housing the impeller.

[0011] In one aspect, the pump device includes legs connected to the pump casing. In one aspect, the legs form a space for disposing a drain pan for receiving the liquid discharged from the suction port below a suction flange part having the suction port. In one aspect, the pump casing includes a suction nozzle in which the suction port is formed. The suction nozzle has a drain port at its lowermost part, and the leg portion forms a space below the drain port for arranging a drain pan that receives the liquid discharged from the drain port.

[0012] In one aspect, the pump casing includes a suction nozzle in which the suction port is formed. The suction nozzle has a drain port at its lowermost part, and the leg portion forms a space for arranging a pipe connectable to the drain port.

[0013] In one aspect, a pump device is provided that includes an impeller, a rotating shaft to which the impeller is fixed, a motor that rotates the rotating shaft, and a pump casing that houses the impeller. The motor includes a bearing that rotatably supports the rotating shaft, a motor casing that has a bearing support portion for supporting the bearing, and a bearing retainer that restricts axial movement of the bearing in the axial direction of the rotating shaft.

[0014] In one aspect, the bearing retainer is fixed to the bearing support portion. In one aspect, the bearing retainer has an annular shape. In one aspect, the pump device is a vertical pump device.

[0015] In one aspect, a vertical pump device is provided. The pump device includes an impeller, a rotating shaft to which the impeller is fixed, an impeller housing structure that houses the impeller, and a gap adjustment structure for adjusting the size of the gap between the impeller and the impeller housing structure.

[0016] In one aspect, the gap adjustment structure includes a distance piece mounted on a stepped portion of the rotating shaft and at least one shim disposed between the distance piece and the impeller.

[0017] In one aspect, a pump casing is provided that includes a suction nozzle having a suction port and a volute portion to which the suction nozzle is connected. The suction nozzle has a flow path that slopes downward from a connection portion connected to the volute portion toward the suction port and has a cross-sectional area that increases from the suction port toward the connection portion.

[0018] In one aspect, the suction nozzle has a widened portion disposed between the suction port and the connection portion. In one aspect, the widened portion extends in the horizontal direction. In one aspect, the cross-sectional area of the flow path increases at a constant rate from the suction port toward the connection portion.

[0019] In one aspect, a pump casing is provided that includes a suction nozzle having a suction port and a volute portion having a volute chamber to which a connection portion of the suction nozzle is connected. The bottom surface of the volute chamber slopes downward from the outer peripheral portion of the volute chamber toward the connection portion.

[0020] In one aspect, the suction nozzle slopes downward from the connection portion toward the suction port. In one aspect, the suction port is disposed at a position lower than the discharge port of the pump casing.

Advantages of the Invention

[0021] The pump casing includes a suction nozzle capable of discharging internal liquid at the lowermost part of its flow path. Therefore, the liquid in the pump casing is discharged to the outside from the suction nozzle by the action of gravity.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a pump device. As shown in FIG. 1, the pump device includes a rotating shaft 1 for pressurizing a liquid to be handled (conveying liquid), an impeller 3 fixed to the rotating shaft 1, a pump casing 5 for housing the impeller 3, a motor 7 for rotating the rotating shaft 1, an intermediate bracket 50 disposed between the pump casing 5 and the motor 7, and a shaft seal device 30 for preventing leakage of high-pressure liquid. The pump casing 5 is provided with a suction port 12 and a discharge port 13, and is made of a corrosion-resistant material (for example, stainless steel). In the embodiment shown in FIG. 1, the rotating shaft 1 is vertically arranged (refer to the direction of the axis CL in FIG. 1). Further, the intermediate bracket 50 has an opening 50a through which the rotating shaft 1 passes, and the shaft seal device 30 seals the conveying liquid leaking from the opening 50a through which the rotating shaft 1 passes to the outside (here, the outside is the motor 7).

[0024] When the motor 7 is driven, the rotation of the motor 7 is transmitted to the rotating shaft 1, and the rotating shaft 1 and the impeller 3 rotate. When the impeller 3 rotates, the liquid flows into the pump casing 5 through the suction port 12 and is pressurized as the impeller 3 rotates. The pressurized liquid is discharged from the discharge port 13. In the embodiment shown in FIG. 1, the impeller 3 is a semi-open type impeller. In one embodiment, the impeller 3 may be a vortex type impeller or a closed type impeller.

[0025] The shaft seal device 30 is a device for sealing the gap between the rotating shaft 1 and the intermediate bracket 50. An example of the shaft seal device 30 is a double mechanical seal. The shaft seal device 30 includes a rotating side seal member (not shown) fixed to the rotating shaft 1 and a stationary side seal member (not shown) fixed to the intermediate bracket 50. Therefore, when the rotating shaft 1 rotates, the rotating side seal member is in sliding contact with the stationary side seal member, and the shaft seal device 30 generates heat.

[0026] Furthermore, in such a pump device, the temperature range of the liquid to be handled may be from low temperature (e.g., minus 25 degrees) to high temperature (e.g., 140 degrees). For example, when the temperature of the liquid to be handled is higher than the allowable temperature of the shaft seal device 30, if the high-temperature liquid to be handled directly contacts the shaft seal device 30, the temperature of the shaft seal device 30 that generates heat due to sliding will further increase. In this embodiment, the liquid to be handled includes a slurry liquid containing a slurry of about 0.05 mm. In one embodiment, the liquid to be handled may be clean water or sewage.

[0027] In this way, the shaft seal device 30 can become extremely hot and malfunction due to contact with the high-temperature liquid to be handled in addition to the sliding of the rotating side seal member and the stationary side seal member. As a result, the shaft seal device 30 cannot fully perform its function, and there is a risk that the liquid will leak to the motor 7 side and the motor 7 will be flooded. Therefore, in the pump device, a structure that can surely prevent the failure of the shaft seal device 30 is desired.

[0028] The pump device includes a normal temperature flow path 60 that keeps the liquid flowing through the shaft seal device 30 within a predetermined temperature range. That is, the pump device forms a flow path 90 (first flow path) through which the opening 50a allows the transport liquid to flow into the shaft seal device 30, and includes a normal temperature flow path 60 (second flow path) that keeps the transport liquid in the flow path 90 within a predetermined temperature range. In this embodiment, the normal temperature flow path 60 is formed in the intermediate bracket 50. More specifically, the intermediate bracket 50 includes a cover portion 51 that covers the opening end 5a of the pump casing 5, and a bracket portion 52 connected to the cover portion 51. And the normal temperature flow path 60 is formed in at least one of the cover portion 51 and the bracket portion 52.

[0029] The normal temperature flow path 60 is formed in both the cover portion 51 and the bracket portion 52. In one embodiment, the normal temperature flow path 60 may be formed only in the cover portion 51 or only in the bracket portion 52. That is, the opening 50a is formed at the opening 51a through which the rotary shaft 1 penetrates in the cover portion 51 and / or the opening 52a through which the rotary shaft 1 penetrates in the bracket portion 52. The opening 50a forms the flow path 90, and the normal temperature flow path 60 is formed in proximity to at least a part of the opening 50a so that the conveyed liquid in the flow path 90 can be maintained within a predetermined temperature range. Here, the temperature range allowed by the product specifications of the shaft seal device 30 is determined. The predetermined temperature range described as "maintaining the conveyed liquid in the flow path 90 within a predetermined temperature range" means that even if the shaft seal device 30 generates heat due to sliding, the temperature remains within the allowable range.

[0030] The normal temperature flow path 60 is arranged radially outward of the shaft diameter from the flow path 90 formed by the outer peripheral surface of the rotary shaft 1 and the inner peripheral surface (opening 50a) of the intermediate bracket 50. When the handled liquid pressurized by the rotation of the impeller 3 flows through this flow path 90, it is heat-exchanged by the fluid in the normal temperature flow path 60 separated by the side wall 60a and then contacts the shaft seal device 30. That is, the handled liquid in the flow path 90 that has reached an appropriate temperature by the fluid in the normal temperature flow path 60 can be used for lubricating the shaft seal device 30. Therefore, the shaft seal device 30 can prevent leakage to the motor 7 side even if the handled liquid is outside the allowable range.

[0031] The normal temperature flow path 60 communicates with the liquid inlet 61 and the liquid outlet 62. A liquid (for example, tap water) flows into the normal temperature flow path 60 from a liquid supply source (not shown) through the liquid inlet 61. The normal temperature liquid (for example, fresh water at 0°C to 65°C) that has flowed into the normal temperature flow path 60 brings the temperature of the liquid existing in the flow path 90 arranged radially inside the normal temperature flow path 60 within a predetermined range (for example, 0°C to 65°C).

[0032] For example, when the temperature of the liquid to be handled is higher than the allowable range of the shaft seal device 30 (e.g., 140 °C), the high-temperature liquid to be handled is cooled by the liquid flowing through the normal temperature flow path 60 (e.g., tap water or industrial water at normal temperature of 0 °C to 35 °C). Conversely, when the temperature of the liquid to be handled is lower than the allowable range of the shaft seal device 30 (e.g., minus 25 °C), the low-temperature liquid to be handled is heated by the liquid flowing through the normal temperature flow path 60 (e.g., tap water or industrial water at normal temperature of 0 °C to 35 °C). Thereby, the temperature of the shaft seal device 30 can be maintained within the allowable range. Thereafter, the liquid that has flowed into the normal temperature flow path 60 is discharged from the liquid outlet 62. The liquid flowing through the normal temperature flow path 60 is an example of a fluid, and as an example of this fluid, it may be tap water or industrial water, or it may be a gas.

[0033] In this way, in order to keep the temperature of the shaft seal device 30 within the allowable range while avoiding the shaft seal device 30 from contacting the liquid to be handled at a temperature outside the allowable range, it is also possible to use clear water (such as tap water or factory pumped water) that is easy to handle as the fluid. Further, in the present embodiment, the fluid in the normal temperature flow path 60 used for adjusting the temperature of the shaft seal device 30 and the liquid to be handled pressurized by the impeller 3 do not mix. Therefore, the temperature of the shaft seal device 30 can be maintained within the allowable range by using a fluid different from the said handling. That is, the user can select the fluid in the normal temperature flow path 60 according to the equipment and the environment. Therefore, the pump device of the present embodiment is particularly effective when the conveyed liquid is a special liquid containing slurry or the like.

[0034] Furthermore, it is preferable that the intermediate bracket 50 is provided with a throttle portion 65 that narrows the flow path of the liquid (i.e., the liquid to be handled) flowing through the shaft seal device 30. The throttle portion 65 shown in FIG. 1 is a member having an annular shape (e.g., a bush). The throttle portion 65 is fixed to the inner peripheral surface of the cover portion 51 that is the inlet of the flow path 90 and is arranged concentrically with the rotating shaft 1. The throttle portion 65 can limit the flow velocity of the liquid to be handled flowing through the flow path 90 by narrowing the flow path 90 of the liquid to be handled to the shaft seal device 30 (i.e., the gap between the throttle portion 65 and the impeller 3). Thereby, the time for heat exchange with the fluid in the normal temperature flow path 60 becomes longer, and a cooling effect can be expected.

[0035] Furthermore, it is preferable that a retention chamber 66 for the liquid flowing into the shaft seal device 30 is formed between the shaft seal device 30 and the throttle portion 65. This retention chamber 66 is an annular chamber formed between the outer peripheral surface of the rotating shaft 1 and the inner peripheral surface of the cover portion 51, and the liquid that has passed through the gap between the throttle portion 65 and the impeller 3 stays in this retention chamber 66.

[0036] During the initial operation of the pump device, due to the rotation of the impeller 3, the handling liquid that has flowed into the pump casing 5 passes through a slight gap between the impeller 3 and the throttle portion 65 and flows into the retention chamber 66. And once the liquid has flowed into the retention chamber 66, it continues to stay in the retention chamber 66 until the pressure inside the pump casing 5 drops sufficiently.

[0037] The normal temperature flow path 60 is arranged outside the retention chamber 66, and the retention chamber 66 communicates with the shaft seal device 30. More specifically, the normal temperature flow path 60 is an annular flow path surrounding the retention chamber 66. Therefore, the liquid present in the retention chamber 66 is more actively heat-exchanged by the liquid flowing through the normal temperature flow path 60.

[0038] In this way, the liquid in contact with the shaft seal device 30 is retained in the retention chamber 66 for a long time and heat-exchanged by the liquid flowing through the normal temperature flow path 60, so that the temperature of the shaft seal device 30 is within the allowable range. That is, the handling liquid within a predetermined temperature range in which the temperature of the shaft seal device 30 is within the allowable range stays in the retention chamber 66, and the liquid staying in the retention chamber 66 is used for lubricating the shaft seal device 30. With such a configuration, the contact between the shaft seal device 30 and a high-temperature or low-temperature liquid outside the predetermined temperature range is inhibited by the liquid present in the retention chamber 66. As a result, the shaft seal device 30 can be prevented from malfunctioning due to contact with a high-temperature or low-temperature liquid.

[0039] In addition, in the present embodiment, the pump device includes a normal temperature flow path 60 that keeps the liquid flowing through the shaft seal device 30 within a predetermined temperature range. However, the protection means for the shaft seal device 30 is not limited to this. In one embodiment, the pump device may not include at least one of the normal temperature flow path 60, the throttle portion 65, the retention chamber 66, etc., as long as the shaft seal device 30 can be protected.

[0040] As described above, the pump device is periodically disassembled and cleaned depending on the usage. At the time of this disassembly and cleaning, it is necessary to completely remove the liquid inside the pump device. However, since the internal flow path of the pump casing 5 has a complex shape, if liquid remains, it is troublesome to remove that liquid.

[0041] In particular, in the pump device according to the present embodiment, since a slurry liquid is included as the liquid to be handled, the slurry is likely to remain inside the pump casing 5 at the time of disassembling and cleaning the pump device. Therefore, in the embodiment described below, the structure of the pump casing 5 that can be easily cleaned with a simple structure will be described with reference to the drawings.

[0042] The pump casing 5 includes a suction nozzle 100 in which a suction port 12 is formed. The pump device is flange-connected to a suction pipe S in which the suction port 12 extends in the horizontal direction and a discharge pipe D in which the discharge port 13 extends in the horizontal direction by fastening means (for example, bolts and nuts). And it is operated in that state. This suction nozzle 100 is inclined downward toward the suction port 12. More specifically, the pump casing 5 further includes a volute portion 101 to which the suction nozzle 100 is connected, and the suction nozzle 100 is inclined downward from the volute portion 101 toward the suction port 12.

[0043] The volute portion 101 forms a volute chamber 102 around the impeller 3 housed in the pump casing 5. The conveying liquid pressurized by the impeller 3 in the volute chamber 102 is discharged from the discharge port 13 extending laterally from the volute chamber 102. The suction nozzle 100 is connected to the center of the bottom of the volute portion 101 and extends downward from the volute portion 101.

[0044] The suction nozzle 100 includes a connection part 100a connected to the volute part 101, a suction flange part 100b having a suction port 12, and a nozzle part 100c connected to the connection part 100a and the suction flange part 100b. The nozzle part 100c extends obliquely downward from the connection part 100a toward the suction flange part 100b, and the suction port 12 of the suction nozzle 100 is disposed below the connection part 100a of the suction nozzle 100. That is, the suction port 12 is the lowermost part in the flow path in the pump casing 5.

[0045] Therefore, when the operator stops the pump device and removes the suction nozzle 100 from the suction pipe S, the liquid in the suction nozzle 100 smoothly flows from the discharge-side flow path of the impeller 3 and the volute part 101 toward the suction port 12 under the action of gravity without staying in the nozzle part 100c as shown by the arrow in FIG. 1. As a result, when disassembling and cleaning the pump device, the liquid in the pump casing 5 flows through the suction nozzle 100 inclined downward without requiring special work and is discharged to the outside through the suction port 12.

[0046] As described above, the pump device of the present embodiment has a simple structure in which the suction nozzle 100 is extended obliquely downward, and when the suction-side pipe (suction pipe S) is removed, the liquid can be made to flow out from the inside of the pump casing 5. With such a structure, the drain work for removing the liquid from the pump casing 5 can be simplified, and the operator can disassemble and clean the pump device without much effort.

[0047] FIG. 2 is a diagram for explaining the effect of the pump casing 5 provided with the suction nozzle 100. In FIG. 2, the suction nozzle 100 according to the embodiment shown in FIG. 1 (see the lower drawing in FIG. 2) and a conventional suction nozzle 1000 as a comparative example (see the upper drawing in FIG. 2) are shown.

[0048] As shown in the upper drawing of FIG. 2, a conventional suction nozzle 1000 includes a connection portion 1000a connected to a volute portion 101, a suction flange portion 1000b having a suction port 12 at substantially the same height as a discharge port 13, and a nozzle portion 1000c having a U-shape connected to the connection portion 1000a and the suction flange portion 1000b. That is, in the conventional suction nozzle 1000, since the suction port 12 and the discharge port 13 are at substantially the same height, the nozzle portion 1000c extending obliquely downward from the connection portion 1000a is curved obliquely upward, and the lowest bottom portion 1000d in the pump casing 5 is formed at the curved portion.

[0049] Therefore, when the suction flange portion 1000b is removed from the suction pipe S, the liquid in the pump casing 5 remains at the bottom portion 1000d. That is, in order to completely remove the liquid in the pump casing 5 with the suction nozzle 1000 shown in the comparative example, an operator needs to perform a drainage operation as shown in the following example. (1) A drainage operation of blowing off the liquid remaining at the bottom portion 1000d by jetting a high-pressure gas. (2) A drainage operation of tilting the pump casing 5 to lower the suction port 12 below the bottom portion 1000d. (3) A drainage operation of using another device (for example, a pump device or a tool).

[0050] On the other hand, in the present embodiment, by making the nozzle portion 100c have a linear shape extending obliquely downward from the connection portion 1000a, the suction port 12 is made the lowest bottom portion 100d in the flow path in the pump casing 5. Therefore, when the suction pipe S is removed from the suction flange portion 100b, the liquid in the pump casing 5 is discharged to the outside through the suction port 12 which is the bottom portion 100d by the action of gravity, and hardly remains in the nozzle portion 100c. As a result, the above-described drainage operation can be omitted, and the cleaning operation in the pump casing 5 can be simplified.

[0051] Furthermore, in the lower side of the present embodiment shown in FIG. 2, the suction nozzle 100 (more specifically, the nozzle portion 100c) extends obliquely downward in a straight line from the connection portion 100a to the suction port 12. Therefore, an operator can easily visually recognize the inside of the suction nozzle 100 through the suction port 12, and as a result, can easily perform an internal inspection (for example, the presence or absence of residues) of the suction nozzle 100.

[0052] Also, in the comparative example, the upper part of the suction flange portion 1000b is arranged side by side with the volute portion 101. Therefore, the suction nozzle 1000 extends outward so that a working space WSa is formed between the volute portion 101 and the suction flange portion 1000b. This working space WSa is a space required for the work of flange-connecting the pump device and the suction pipe S by a fastener (for example, a combination of a bolt and a nut) 110.

[0053] In contrast, since the suction flange portion 100b of the suction nozzle 100 of the present embodiment is arranged at a position lower than the volute portion 101, a working space WSa can also be formed between the volute portion 101 and the nozzle portion 100c below it.

[0054] That is, in the suction nozzle 100, a working space WSa can also be secured below the volute portion 101. With such a structure, the distance D1 between the center line CL of the pump device and the suction flange portion 100b can be made smaller by a difference DS than the distance D2 between the center line CL of the pump device and the suction flange portion 1000b. That is, in the present embodiment, the length of the suction nozzle 100 extending outward from the volute portion 101 can be made shorter than in the comparative example. Therefore, the pump device provided with the suction nozzle 100 according to the present embodiment can make its overall size compact.

[0055] FIG. 3 is a diagram showing yet another embodiment of the pump device. In the embodiment shown in FIG. 3, the pump device includes legs 150 and 151 connected to the pump casing 5. By providing the legs 150 and 151, the pump device can stand on its own, so that an operator can easily carry the pump device.

[0056] Furthermore, it is preferable that the legs 150 and 151 form a space with a height H between the suction flange portion 100b and the floor FL. By forming the space with the height H, a drain pan 155 for collecting waste liquid can be arranged directly below the suction flange portion 100b. As shown in FIG. 3, a drain pan 156 may be arranged directly below the discharge port 13. Thereby, the waste liquid flowing out when the pipe is removed can be easily collected.

[0057] FIG. 4 is a view seen from the direction of line A in FIG. 3. In FIG. 4, the suction flange portion 100b has a grounding surface, and the two legs 151 are formed at the grounding surface of the suction flange portion 100b. The suction flange portion 100b and the legs 151 are integrally formed members. The drain pan 155 is arranged between the two legs 151 adjacent to each other. Note that in this embodiment, the suction flange portion 100b only needs to have a grounding surface and is not limited to the shape shown in the figure. Any shape is acceptable as long as it can be flange-connected to the suction pipe S.

[0058] FIG. 5 is a diagram showing another embodiment of the suction flange portion 100b. In the embodiment shown in FIG. 5, the suction flange portion 100b has a circular shape, and the two legs 151 extend downward from the lower part of the suction flange portion 100b. As shown in FIG. 5, in order to arrange the drain pan 155 below the suction port 12, the distance W2 between the legs 151 adjacent to each other is larger than the diameter W1 of the suction port 12 (W2>W1). With such a configuration, the drain pan 155 is arranged below the suction port 12, and the two legs 151 are arranged on both sides of the drain pan 155.

[0059] By removing the suction pipe from the suction nozzle 100, the liquid inside the suction nozzle 100 does not stay in the nozzle part 100c, but due to the action of gravity, it flows from the volute part 101 towards the suction port 12 and flows out from the suction port 12. The drain pan 155 arranged directly below the suction flange part 100b can receive the liquid flowing out from the suction port 12.

[0060] Since the suction port 12 is the lowest bottom part 100d in the flow path inside the pump casing 5, the bottom part of the suction flange part 100b is arranged at the lowest position in the pump device. Therefore, as shown in FIGS. 4 and 5, the suction flange part 100b and the leg part 151 can be easily used in combination. Furthermore, by providing the leg parts 150 and 151, a working space WSc can be formed below the suction flange part 100b. This working space WSc is a space for connecting the suction nozzle 100 to the suction pipe by the fastener 110. By forming the working space WSc, the operator can easily attach and detach the suction nozzle 100 and the suction pipe.

[0061] FIG. 6 is a view showing another embodiment of the leg part. As shown in FIG. 6, the pump device may include a leg part 160 connected to the intermediate bracket 50 via the pump casing 5 instead of the leg parts 150 and 151. In the embodiment shown in FIG. 6, a protrusion 161 protruding outward from the cover part 51 is formed on the cover part 51 of the intermediate bracket 50. Similarly, a protrusion 162 protruding outward from the pump casing 5 is formed on the pump casing 5. The protrusion 161 of the cover part 51 and the protrusion 162 of the pump casing 5 are connected to each other by a fastener (for example, a bolt) 165.

[0062] The leg part 160 includes a base part 166, a wall part 167 extending vertically from the base part 166, and a connection part 168 fixed to the wall part 167 and connectable to the protrusion 162 of the pump casing 5. The protrusion 162 and the connection part 168 are connected to each other by a fastener (for example, a bolt) 170.

[0063] With such a configuration, the intermediate bracket 50 and the pump casing 5 are connected to each other by the fastener 165, and the pump casing 5 and the leg portion 160 are connected to each other by the fastener 170. Also in the embodiment shown in FIG. 6, by providing the leg portion 160, the drain pans 155, 156 (see FIG. 3) can be arranged below the pump casing 5, and a working space WSc (see FIG. 3) for connecting the suction nozzle 100 to the suction pipe can be secured.

[0064] FIG. 7 is a view showing another embodiment of the suction nozzle 100. Also in the embodiment shown in FIG. 7, the pump device includes leg portions 150, 151. In the embodiment shown in FIG. 7, the suction nozzle 100 includes a nozzle portion 100c having a U-shape. As shown in FIG. 7, the nozzle portion 100c has a drain port 181 at its lowermost portion 180. The drain port 181 is a through hole for discharging the liquid in the nozzle portion 100c to the outside. Usually, during the operation of the pump device, the drain port 181 is closed by a lid (not shown). When disassembling and cleaning the pump casing 5, the lid is removed, and the liquid in the pump casing 5 is discharged through the drain port 181.

[0065] In the embodiment shown in FIG. 7, the leg portions 150, 151 form a space with a height H between the lowermost portion 180 of the nozzle portion 100c and the floor FL. By forming the space with the height H, when discharging the liquid, a drain pan (not shown) can be arranged directly below the drain port 181, or a drain pipe can be connected to the drain port 181.

[0066] Furthermore, by providing the leg portions 150, 151, the effects that the pump device can be easily carried and a working space WSc can be formed below the suction flange portion 100b can be achieved.

[0067] The pump device according to the above-described embodiment is a vertical pump device capable of transporting a liquid (i.e., slurry liquid) containing slurry of about 0.05 mm (i.e., light slurry). In order to transport the slurry liquid, the impeller 3 is preferably a semi-open type impeller. By adopting a semi-open type impeller, it is possible to suppress the slurry from being pinched between the pump casing 5 and the impeller 3. Further, in order to obtain a large head with respect to the flow rate, the pump device includes an impeller 3 having a larger diameter than a general impeller, and rotates the rotating shaft 1 at a low speed (for example, 1500 min -1 ).

[0068] With such a structure, the suction pressure of the pump increases, and as a result, a large thrust force that pushes the impeller 3 upward (i.e., in the direction toward the cover portion 51) is generated. If the size of the gap between the impeller 3 and the cover portion 51 changes due to this thrust force, there is a risk that the pump device cannot exhibit the desired performance, or that the slurry may be pinched in the gap between the impeller 3 and the cover portion 51. Therefore, in the embodiment described below, the pump device has a structure that can limit the upward movement of the impeller 3 even when a large thrust force is generated.

[0069] FIG. 8 is a diagram showing an embodiment of the motor 7. As shown in FIG. 8, the motor 7 includes a first bearing 201A and a second bearing 201B that rotatably support the rotating shaft 1, a motor casing 203 having a first bearing support portion 202A and a second bearing support portion 202B that support the first bearing 201A and the second bearing 201B, and a bearing retainer 205 that restricts the movement of the first bearing 201A in the axial direction CL of the rotating shaft 1.

[0070] The rotating shaft 1 extends through the motor casing 203, and a cooling fan 206 is fixed to the end 1a of the rotating shaft 1. The cooling fan 206 is housed in a fan cover 209 connected to the motor casing 203. The second bearing 201B is a counter-loading side bearing arranged adjacent to the cooling fan 206. The first bearing 201A is a loading side bearing arranged at a distance from the cooling fan 206.

[0071] Between the first bearing 201A and the second bearing 201B, a rotor 210 and a stator 211 for rotating the rotating shaft 1 are arranged. The rotor 210 is fixed to the rotating shaft 1, and the stator 211 surrounds the rotor 210 and receives electric power through the winding (coil) 211b to form a rotating magnetic field. The stator 211 includes a stator core 211a and a plurality of windings 211b wound around the stator core 211a. The rotor 210 rotates by the rotating magnetic field formed between the rotor 210 and the stator 211, and the rotating shaft 1 to which the rotor 210 is fixed rotates together with the rotor 210.

[0072] The first bearing 201A is supported by the first bearing support portion 202A, and the second bearing 201B is supported by the second bearing support portion 202B. As described above, when a thrust force for pushing up the impeller 3 is generated, this thrust force acts on the first bearing 201A and the second bearing 201B through the rotating shaft 1. The thrust force acting on the second bearing 201B is received by the second bearing support portion 202B, while the thrust force acting on the first bearing 201A is not received by the first bearing support portion 202A. Therefore, the motor 7 is provided with a bearing retainer 205 for receiving the thrust force acting on the first bearing 201A.

[0073] FIG. 9 is a view showing the bearing retainer 205. As shown in FIG. 9, the bearing retainer 205 is fixed to the first bearing support portion 202A by a plurality of fasteners 212. The bearing retainer 205 has an annular shape and is arranged concentrically with the rotating shaft 1. The plurality of fasteners 212 are preferably arranged at equal intervals along the circumferential direction of the bearing retainer 205. The bearing retainer 205 has through holes 207 into which the fasteners 212 can be inserted. The first bearing support portion 202A has fastening holes 208 into which the fasteners 212 can be inserted. By inserting the fasteners 212 into these through holes 207 and fastening holes 208 and tightening the fasteners 212, the bearing retainer 205 is fixed to the first bearing support portion 202A.

[0074] According to the present embodiment, the bearing retainer 205 can surely receive the thrust force acting on the first bearing 201A. Therefore, even when a large upward thrust force is generated in the impeller 3, the pump device can maintain the size of the gap between the impeller 3 and the cover portion 51 at a desired size.

[0075] As described above, the pump device can transport a slurry liquid containing light slurry. If the slurry liquid is continuously transported, the components of the pump device (such as the impeller 3, the pump casing 5, and the cover portion 51) that come into contact with the slurry liquid may wear. Due to this wear, the size of the gap between the impeller 3 and its peripheral members (for example, the pump casing 5 and the cover portion 51) may change, and as a result, the performance of the pump device may be adversely affected. Furthermore, the pump device can also transport a high-temperature handling liquid. In this case, due to the influence of the heat of the handling liquid, the components of the pump device may thermally expand, and as a result, the size of the gap between the impeller 3 and its peripheral members may change. Therefore, in the embodiment described below, the pump device is provided with a gap adjustment structure for adjusting the size of the above gap.

[0076] FIG. 10 is a diagram showing a gap adjustment structure. In the embodiment described below, the peripheral members (for example, the pump casing 5 and the cover portion 51) of the impeller 3 may be collectively referred to as an impeller housing structure 300. As shown in FIG. 10, the pump device includes an impeller housing structure 300 that houses the impeller 3, and a gap adjustment structure 305 for adjusting the size of the gap between the impeller 3 and the impeller housing structure 300.

[0077] FIG. 11 is an enlarged view of the gap adjustment structure 305. As shown in FIG. 11, the gap adjustment structure 305 includes a spacer 306 mounted on the stepped portion 1b of the rotating shaft 1, and at least one shim 307 disposed between the spacer 306 and the impeller 3.

[0078] Each of the spacer 306 and the shim 307 has an annular shape and is arranged concentrically with the rotating shaft 1. The shim 307 has a minute thickness (for example, 0.1 mm). The operator adjusts the size of the gap between the impeller 3 and the impeller housing structure 300 by arranging one or more shims 307 with the spacer 306 mounted.

[0079] When transporting a high-temperature handling liquid, the operator determines the number of shims 307 to be arranged in consideration of the thermal expansion of the impeller 3 and the impeller housing structure 300. According to the present embodiment, the size of the gap between the impeller 3 and the impeller housing structure 300 can be freely adjusted by a simple method of adjusting the number of shims 307. In particular, in the present embodiment, since the pump device has a structure in which the impeller 3 is directly fixed to the rotating shaft 1 extending from the motor 7, it is particularly effective to provide the gap adjustment structure 305 that can adjust the gap without requiring a complicated structure.

[0080] According to this embodiment, even when the impeller 3 and the impeller housing structure 300 are worn due to the conveyance of the slurry liquid, the operator can adjust the size of the gap between the impeller 3 and the impeller housing structure 300 to an appropriate size by adding the shim 307 during the maintenance of the pump device. Therefore, the cost of the pump device can be reduced.

[0081] According to this embodiment, by providing the gap adjustment structure 305, the pump device does not need to have a special structure for conveying the slurry liquid, and can also convey handling liquids such as clear water. More specifically, when the operator conveys a handling liquid such as clear water, the gap adjustment structure 305 can be removed, and when the slurry liquid is conveyed, the gap adjustment structure 305 can be attached.

[0082] FIG. 12 is a diagram showing still another embodiment of the pump device. As shown in FIG. 12, the suction nozzle 100 is inclined downward from the volute portion 101 toward the suction port 12. With such a structure, the length of the suction nozzle 100 extending outside the volute portion 101 can be shortened, and as a result, the overall size of the pump device can be made compact (see FIG. 2).

[0083] In order to make the size of the pump device compact, it is desirable to reduce the size of the suction nozzle 100 in the height direction and the size of the suction nozzle 100 in the width direction (more specifically, the direction from the center line CL of the pump device toward the suction flange portion 100b). Also, it is important to minimize the change in the shape of the suction nozzle 100 and increase the cross-sectional area (cross-sectional area in the height direction) of the flow path of the suction nozzle 100 at a constant rate of change. This is because when the flow rate on the suction side of the pump casing 5 is generally greatly restricted, problems such as cavitation occur. Therefore, it is desirable that the suction nozzle 100 has a shape that suppresses pressure loss while ensuring a predetermined cross-sectional area in its flow path.

[0084] FIG. 13 is a cross-sectional view taken along line B-B of FIG. 12. FIG. 14 is a view seen from the direction of line C of FIG. 12. As shown in FIGS. 13 and 14, the suction nozzle 100 has a flow path 400 that slopes downward from the volute portion 101 (more specifically, the connecting portion 100a connected to the volute portion 101) toward the suction port 12, and a wide portion 100d disposed between the suction port 12 and the connecting portion 100a such that the cross-sectional area of the flow path 400 increases at a constant rate of change from the suction port 12 toward the connecting portion 100a.

[0085] The wide portion 100d extends horizontally in order to reduce the size of the suction nozzle 100 in the height direction and realize a compact pump device. The flow rate of the liquid to be handled in the wide portion 100d increases. Therefore, by providing the wide portion 100d, the suction nozzle 100 can increase the cross-sectional area of its flow path 400 at a constant rate of change. As a result, the pump device can ensure the required flow rate while preventing the occurrence of cavitation. Further, the suction nozzle 100 can be inclined at an optimal angle to suppress the pressure loss.

[0086] FIG. 15 is a view showing another embodiment of the pump casing. As shown in FIG. 15, the pump casing 5 may have a drain structure. More specifically, the volute portion 101 of the pump casing 5 has a volute chamber 102 in which the impeller 3 is accommodated. The volute chamber 102 is formed with a bottom surface 102a located below the impeller 3 and an outer peripheral portion 102b located outside the impeller 3. The bottom surface 102a of the volute chamber 102 slopes downward from the outer peripheral portion 102b of the volute chamber 102 toward the connecting portion 100a.

[0087] By forming such a bottom surface 102a, the liquid to be handled present in the volute chamber 102 after the operation of the pump device stops flows down the bottom surface 102a due to the action of gravity and is smoothly discharged from the volute chamber 102. In the embodiment shown in FIG. 15, the suction nozzle 100 is inclined downward toward the suction port 12. Therefore, the liquid to be handled discharged from the volute chamber 102 flows down the nozzle portion 100c that extends obliquely downward from the connection portion 100a toward the suction flange portion 100b and is smoothly discharged from the suction port 12.

[0088] As shown in FIG. 15, the suction port 12 is disposed at a position lower than the discharge port 13 and on the side of the suction flange portion 100b. Therefore, the liquid to be handled remaining in the volute chamber 102 is surely guided to the suction nozzle 100 without flowing toward the discharge port 13 side.

[0089] In the embodiment shown in FIG. 15, the drain structure applied to the pump casing 5 according to the embodiment shown in FIG. 1 has been described. However, such a drain structure is also applicable to the pump casing 5 according to the embodiment shown in FIG. 12.

[0090] The above-described embodiments are described for the purpose of enabling those having ordinary knowledge in the technical field to which the present invention pertains to practice the present invention. Various modifications of the above embodiments can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments and is construed in the broadest scope in accordance with the technical idea defined by the claims.

Explanation of Reference Numerals

[0091] 1 Rotating shaft 1a End portion 1b Step portion 3 Impeller 5 Pump casing 5a Open end 7 Motor 12 Suction port 13 Discharge port 30 Shaft seal device 50 Intermediate bracket 50a Opening 51 Cover part 51a Opening 52 Bracket part 52a Opening 60 Normal temperature flow path (second flow path) 60a Side wall 61 Liquid inlet 62 Liquid outlet 65 Throttle part 90 Flow path (first flow path) 100 Suction nozzle 100a Connection part 100b Flange part 100c Nozzle part 100d Wide part 101 Volute part 102 Volute chamber 102a Bottom surface 102b Outer peripheral surface 150, 151 Legs 155, 156 Drain pan 160 Legs 161, 162 Protrusions 165 Fastener 166 Base part 167 Wall part 168 Connection part 170 Fastener 180 Lowest part 181 Drain port 201A First bearing 201B Second bearing 202A First bearing support part 202B Second bearing support part 203 Motor casing 205 Bearing retainer 206 Cooling fan 207 Through hole 208 Fastening hole 209 Fan cover 210 Rotor 211 Stator 211a Stator core 211b winding 212 fastener 300 impeller housing structure 305 gap adjustment structure 306 spacer 307 shim 400 flow path 1000 suction nozzle 1000a connection part 1000b flange part 1000c nozzle part

Claims

1. A pump casing having a suction port connected to a suction pipe extending in the horizontal direction, wherein the pump casing includes a suction nozzle having a connection part, a suction flange part having the suction port, and a nozzle part connected to the connection part and the suction flange part, the pump casing includes a volute part connected to the connection part, the suction nozzle is inclined obliquely downward from the connection part toward the suction flange part without having a protruding part on its flow path, the nozzle part includes a linear shape extending obliquely downward to the suction port with a constant inclination, the pump casing.

2. The pump casing according to claim 1, wherein the suction port is the lowest bottom part in the pump casing.

3. The suction port is disposed below the volute part, and a working space for connecting the suction nozzle to the suction pipe is formed between the volute part and the suction nozzle. The pump casing according to claim 1.

4. An impeller, a rotating shaft to which the impeller is fixed, a motor for rotating the rotating shaft, and a pump casing according to any one of claims 1 to 3 for accommodating the impeller. A pump device.

5. The pump device according to claim 4, wherein the pump device includes legs connected to the pump casing.

6. The leg forms a space for disposing a drain pan for receiving the liquid discharged from the suction port below the suction flange part having the suction port. The pump device according to claim 5.

Images