Horizontal Pump

Abstract

To shorten the duration of an air-water mixing operation state in a horizontal shaft pump.SOLUTION: A horizontal shaft pump 1 comprises a pump casing 2, a motor 10 arranged on the downstream side of a suction port 3 in an internal space 17 of the pump casing 2, and an impeller 18 arranged on the upstream side where the suction port 3 is located in the internal space 17. The impeller 18 is constituted so as to discharge flowing water sucked from the suction port 3, toward a discharge port 4 through the internal space 17. The pump casing 2 is provided with an exhaust part 20 communicating with the internal space 17 for exhausting air accumulated in the internal space 17 to the outside. The exhaust part 20 is arranged on the downstream side of the position of the impeller 18.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a horizontal pump. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a horizontal shaft pump such as that disclosed in Patent Document 1 has been proposed as a full-speed, full-water-level type horizontal shaft pump that can be installed in a flowing water channel or a water tank.

[0003] Specifically, Patent Document 1 discloses a horizontal shaft pump including a pump casing having an inlet and a discharge port, a motor and a rotating shaft disposed within the pump casing, and an impeller disposed on the inlet side of the pump casing and fixed to the rotating shaft so as to be rotatable by being driven by the motor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-029107 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in a full-speed, full-water level horizontal shaft pump such as that described in Patent Document 1, when the impeller is not fully immersed in the flowing water inside the pump casing, when the operating water level reaches a level at which the horizontal shaft pump draws in air, the rotation of the impeller causes the pump to enter an operating state in which both flowing water and air are simultaneously drawn in through the suction port of the pump casing (i.e., an air-water mixed operating state).

[0006] In the above horizontal shaft pump, for example, when the water level in the pump casing is dropping, the impeller may not be fully submerged in the water inside the pump casing. In such a state, the impeller sucks in air along with the flowing water, and so-called air pockets tend to form inside the pump casing. These air pockets reduce the drainage capacity of the horizontal shaft pump. As a result, the horizontal shaft pump continues the air-water mixing operation until the water level reaches the standby operation state after the drainage capacity is lost.

[0007] In contrast, for example, when the water level in the pump casing rises from the standby operation state, the pump will transition to the normal operation state after passing through the air-water mixed operation state. However, in the process in which the water level in the pump casing rises, most of the impeller in the pump casing becomes submerged in water, and the normal operation state does not normally transition unless the air accumulated in the space behind the impeller in the pump casing is exhausted to the outside from the discharge port. As a result, the horizontal pump continues the air-water mixed operation state.

[0008] Here, for example, in a storm water drainage pumping station to which a horizontal shaft pump is applied, the horizontal shaft pump is usually used for a long period of time, and it is required to keep the horizontal shaft pump in a usable state for a long period of time. However, in a conventional full-speed full-level type horizontal shaft pump, if the duration of the air-water mixed operation state increases, the vibration generated in the air-water mixed operation state may cause damage to the bearings, increase in shaft vibration, and loosening of each fastening part. In other words, it is not preferable for the above-mentioned air-water mixed operation state to continue for a long period of time in a horizontal shaft pump. For this reason, the above-mentioned conventional horizontal shaft pump needed to be improved to shorten the duration of the air-water mixed operation state as much as possible.

[0009] The present disclosure has been made in consideration of the above points, and has an object to shorten the duration of the air-water mixed operation state in a horizontal shaft pump. [Means for solving the problem]

[0010] In order to achieve the above object, the first disclosure is a horizontal axis pump that can be installed in a flowing waterway or a water tank, and includes a pump casing having an inlet located on the upstream side and an outlet located on the downstream side, and an internal space that communicates between the inlet and the outlet, a motor located downstream of the inlet in the internal space, and an impeller located upstream of the inlet in the internal space and rotatable by driving of the motor. The impeller is configured to discharge the flowing water sucked from the inlet through the internal space toward the outlet. The pump casing is provided with at least one exhaust section that communicates with the internal space and exhausts air accumulated in the internal space to the outside, and the exhaust section is provided with at least one exhaust section that penetrates the pump casing and is located downstream of the position of the impeller. The internal space and the outside Always communication When the water level in the internal space is decreasing, air accumulated in the internal space is discharged to the outside through the exhaust portion due to the internal pressure of the internal space.

[0011] In the first disclosure, at least one exhaust section communicates with the internal space of the pump casing and is disposed downstream of the impeller position in the pump casing. With this configuration, for example, when the water level in the internal space is dropping, the air accumulated in the internal space of the pump casing is quickly exhausted from the exhaust section to the outside due to the internal pressure of the internal space. As this exhaust continues, the air pool in the internal space is eliminated by the exhaust section located downstream of the impeller position, making it easier to maintain the internal space filled with running water. As a result, the running water in the internal space is discharged from the discharge port until the water level becomes low. That is, the drainage capacity of the horizontal axis pump is maintained. As a result, the duration of the air-water mixed operation state is shortened, and the operation state is quickly switched to the standby operation state.

[0012] In the first disclosure, in the standby operation state, the running water in the internal space is not discharged from the discharge port, but the air accumulated in the internal space is exhausted to the outside from the exhaust part. By continuing this exhaust, the internal space located behind the impeller is maintained in a state filled with running water.

[0013] Furthermore, in the first disclosure, even when the water level in the internal space is rising, the air accumulated in the internal space is quickly exhausted to the outside from the exhaust section due to the internal pressure of the internal space. As this exhaust continues, the running water in the internal space is filled to a water level where the impeller is fully immersed in the running water. Then, when the impeller is fully immersed in the running water in the internal space, the running water in the internal space is instantly discharged from the discharge port. As a result, the duration of the air-water mixed operation state is shortened, and the operation state is quickly switched to the normal operation state.

[0014] In this way, in the first disclosure, the air accumulated in the internal space is exhausted to the outside from the exhaust section, so that the duration of the air-water mixed operation state can be shortened. As a result, it is possible to maintain the horizontal shaft pump in a usable state for a long period of time, for example, in a storm water drainage pumping station.

[0015] In the first disclosure, the exhaust portion includes at least one exhaust pipe extending through the pump casing, The interior space and the exterior Always Connect It has a through hole.

[0016] In the first disclosure, a simple configuration such as a through hole makes it possible to properly exhaust air that has accumulated in the internal space of the pump casing to the outside.

[0017] The second disclosure is based on the first disclosure, in which the impeller is arranged so that its center of rotation coincides with the axis of the pump casing, and the exhaust section is arranged in the pump casing above the center of rotation of the impeller.

[0018] In the second disclosure, air accumulated in the internal space is exhausted to the outside from an exhaust section located above the rotation center of the impeller in the pump casing. This makes it possible to position the water level in the internal space above the rotation center of the impeller, for example, when the water level in the internal space is rising. In other words, it is possible to make the impeller fully submerged in running water in the internal space. As a result, the duration of the air-water mixed operation state is shortened, and the operation state can be quickly transitioned to the normal operation state.

[0019] The third disclosure is the second disclosure, wherein the exhaust section is an impeller More than 80% of The portion is positioned above the water level of the interior space when it is immersed in running water in the interior space.

[0020] In this third disclosure, the air accumulated in the internal space is blown into the impeller More than 80% of When the water level in the internal space rises, for example, most of the impeller can be easily maintained in a state where it is submerged in the flowing water in the internal space. As a result, the duration of the air-water mixed operation state is shortened, and the normal operation state can be quickly transitioned to.

[0021] A fourth disclosure is any one of the first to third disclosures, further comprising a motor casing disposed in the internal space and formed to surround the entire circumference of the motor. The motor is provided with a shaft that can be rotated by driving the motor. The motor is disposed so that the center of rotation of the shaft coincides with the axis of the pump casing. The exhaust section is disposed above the water level in the internal space when the motor casing is immersed in the running water in the internal space up to a position corresponding to the center of rotation of the shaft.

[0022] In the fourth disclosure, air accumulated in the internal space is exhausted to the outside from an exhaust section located above the water level in the internal space when the motor casing is submerged in the running water in the internal space up to a position corresponding to the rotation center of the shaft. This allows at least half of the motor casing to be submerged in the running water in the internal space when the water level in the internal space is rising, for example. As a result, the running water in the internal space can absorb heat generated by the motor.

[0023] The fifth disclosure is the fourth disclosure, wherein the exhaust portion is a motor casing. More than 80% of The portion is positioned above the water level of the interior space when it is immersed in running water in the interior space.

[0024] In this fifth disclosure, the air that has accumulated in the internal space is discharged into the motor casing. More than 80% of When the water level in the internal space is rising, for example, most of the motor casing can be immersed in the running water in the internal space. As a result, the heat generated by the motor can be absorbed by the running water in the internal space.

[0025] No. 6 In any one of the first to fifth disclosures, the exhaust section is Through hole A pipe portion extending horizontally from the outer circumferential surface of the pump casing and communicating with the Includes .

[0026] This 6 In the disclosure, Through holes and Horizontally extending pipe section and With this simple configuration, air accumulated in the internal space of the pump casing can be exhausted while being guided horizontally from the pipe portion to the outside, depending on the conditions of the waterway or water tank in which the horizontal shaft pump is installed.

[0027] No. 7 In any one of the first to fifth disclosures, the exhaust section , KanAn approximately L-shaped elbow that communicates with the through hole and is fixed to the pump casing Materials include.

[0028] This 7 In the disclosure, a simple configuration using a through hole and an elbow member makes it possible to exhaust air that has accumulated in the internal space of the pump casing while guiding it in a predetermined direction from the through hole and the elbow member to the outside.

[0029] No. 8 The disclosure of 7 In the disclosure, the elbow member is configured such that one end is fixed to the outer circumferential surface of the pump casing, while the other end opens upward.

[0030] This 8 In the disclosure, an elbow member with an upward opening at the other end allows air accumulated in the internal space of the pump casing to be appropriately vented by guiding it upward through the through hole and the elbow member to the outside, depending on the conditions of the waterway or water tank in which the horizontal shaft pump is installed.

[0031] No. 9 The disclosure of 7 In the disclosure, the elbow member is configured such that one end is fixed to the outer circumferential surface of the pump casing, while the other end opens downward.

[0032] This 9 In the disclosure, an elbow member whose other end opens downward allows air accumulated in the internal space of the pump casing to be appropriately vented by guiding it downward toward the outside through the through hole and the elbow member, depending on the conditions of the waterway or water tank in which the horizontal shaft pump is installed. Effect of the Invention

[0033] As described above, according to the present disclosure, the duration of the air-water mixed operation state in the horizontal shaft pump can be shortened. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is an overall perspective view of a horizontal shaft pump according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a side view of the horizontal axis pump illustrating a state in which the water level in the internal space is decreasing. [Figure 4] FIG. 4 is a view equivalent to FIG. 3 illustrating the water level in the internal space in the standby operation state. [Diagram 5] FIG. 5 is a view equivalent to FIG. 3 illustrating the state in which the water level in the internal space is rising. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a view corresponding to FIG. 7 and showing a first modified example of the embodiment of the present disclosure. [Figure 9] FIG. 9 is a view corresponding to FIG. 7 and showing a second modified example of the embodiment of the present disclosure. [Figure 10] FIG. 10 is a view corresponding to FIG. 7 and showing a third modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following description of the embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its application, or its uses.

[0036] (Horizontal shaft pump) FIG 1 shows an entire horizontal shaft pump 1 according to an embodiment of the present disclosure. The horizontal shaft pump 1 is a full-speed, full-water-level submersible pump that can be installed in a flowing waterway or a water tank. The horizontal shaft pump 1 is configured as a part of a pump gate system (not shown) installed, for example, in a drainage route connecting a waterway and a river. Note that the above-mentioned "full-speed, full-water level" means that the pump can be operated at the rated speed at any water level except for the water level at which the pump runs dry.

[0037] 1 to 5 extends in a direction intersecting the vertical direction. In the following description, the side where a suction port 3 (described later) is located may be referred to as the upstream side of the horizontal shaft pump 1, and the side where a discharge port 4 (described later) is located may be referred to as the downstream side of the horizontal shaft pump 1.

[0038] (straightening plate) As shown in Figs. 1 to 5, the horizontal shaft pump 1 is provided with a flow straightening vane 7. The flow straightening vane 7 is attached to the suction port 3 of the pump casing 2, which will be described later. The flow straightening vane 7 is a member for guiding low-level flowing water to the suction port 3, and is configured to cover both the left and right sides and the upper side of the suction port 3. The flow straightening vane 7 may be formed by machining (pressing, etc.) using a single flat plate material, or may be formed by joining or assembling multiple flat plate materials.

[0039] (Fixed drain pipe) As shown in Figs. 1 to 5, the horizontal shaft pump 1 is provided with a fixed drain pipe 8. The fixed drain pipe 8 is attached to the discharge port 4 of the pump casing 2, which will be described later. The fixed drain pipe 8 is configured as a part of a communication pipe that horizontally penetrates a gate door (not shown). By connecting the horizontal shaft pump 1 to the fixed drain pipe 8, the gate door (not shown) and the horizontal shaft pump 1 become an integrated drainage system. The fixed drain pipe 8 is configured so that a portion (flange portion) facing the discharge port 4 engages with an engaging member 6, which will be described later.

[0040] (Pump casing) As shown in Fig. 1 to Fig. 5, the horizontal shaft pump 1 includes a pump casing 2. The pump casing 2 has a substantially cylindrical shape (see Fig. 6 and Fig. 7). The pump casing 2 extends along the extension direction of an axis A.

[0041] The pump casing 2 in this embodiment is composed of first to fourth casing sections 2a to 2d. The first to fourth casing sections 2a to 2d are arranged in this order from the upstream side to the downstream side, starting from the first casing section 2a to the fourth casing section 2d.

[0042] The pump casing 2 has a suction port 3 and a discharge port 4. Specifically, the suction port 3 is configured as an opening located on the left side of the paper in Fig. 2 of the first casing part 2a. The discharge port 4 is configured as an opening located on the right side of the paper in Fig. 2 of the fourth casing part 2d.

[0043] An underwater cable 5 for supplying power to a motor 10 (described later) is connected to the upper part of the third casing part 2c. An engagement member 6 for attaching a fixed drain pipe 8 (described later) to the discharge port 4 side of the pump casing 2 (fourth casing part 2d) is provided on the upper part of the fourth casing part 2d near the discharge port 4.

[0044] (Motor and Shaft) As shown in Fig. 2, the horizontal shaft pump 1 includes a motor 10 and a shaft 11. The motor 10 and the shaft 11 are housed inside a motor casing 12, which will be described later. The motor 10 is disposed downstream of the suction port 3 in an internal space 17, which will be described later, of the pump casing 2. The shaft 11 is configured to be rotatable by being driven by the motor 10. The motor 10 is disposed such that the center of rotation of the shaft 11 coincides with the position of an axis A of the pump casing 2.

[0045] (Motor casing) The horizontal shaft pump 1 includes a motor casing 12. The motor casing 12 is disposed downstream of the suction port 3 in an internal space 17 (described below) of the pump casing 2. The motor casing 12 has a generally cylindrical shape configured to surround the entire circumference of the motor 10. The longitudinal direction of the motor casing 12 extends along the extension direction of the axis A. The motor casing 12 is configured to be supported by the third casing portion 2c (see FIG. 2).

[0046] (1st and 2nd bearings) The horizontal shaft pump 1 includes a first bearing 13 and a second bearing 14 for rotatably supporting the shaft 11. The first bearing 13 is attached to a midway portion of the shaft 11 near the end located on the upstream side. The first bearing 13 is made up of, for example, two bearings. The second bearing 14 is attached to an end of the shaft 11 located downstream of the motor 10. The second bearing 14 is made up of, for example, a single bearing.

[0047] (First and second bearing support parts) The horizontal shaft pump 1 includes a first bearing support portion 15 for supporting the first bearing 13, and a second bearing support portion 16 for supporting the second bearing 14. The first bearing support portion 15 is configured to surround the outer circumferential surface of the first bearing 13 from the outside. The second bearing support portion 16 is configured to surround the outer circumferential surface of the second bearing 14 from the outside.

[0048] In this embodiment, the first bearing support 15 is configured as a separate member from the motor casing 12, and is attached to the upstream end of the motor casing 12. On the other hand, the second bearing support 16 is configured as a part of the motor casing 12, and is formed integrally with the downstream end of the motor casing 12.

[0049] (Interior space) As shown in Fig. 2, the pump casing 2 has an internal space 17. The internal space 17 is in communication with the suction port 3 and the discharge port 4. As shown in Fig. 7, around the motor casing 12, the internal space 17 is configured as a space having a generally annular shape in cross section, located between the inner circumferential surface of the pump casing 2 and the outer circumferential surface of the motor casing 12. With this configuration, the flowing water in the internal space 17 receives heat generated in the motor 10 via the motor casing 12.

[0050] (Impeller) As shown in Figs. 2 to 6, the horizontal shaft pump 1 includes an impeller 18. The impeller 18 is disposed upstream of the suction port 3 in the internal space 17 of the pump casing 2. Specifically, the impeller 18 is attached to an end of the shaft 11 that is located upstream of the motor 10. The impeller 18 is also attached to an end of the first bearing support portion 15 that is located upstream.

[0051] Impeller 18 is disposed so that its center of rotation coincides with the position of axis A. Impeller 18 is rotatable together with shaft 11 when driven by motor 10. Impeller 18 is configured to pressurize running water sucked in from suction port 3, and discharge the running water through internal space 17 toward discharge port 4. In the schematic vertical cross-sectional view shown in FIG. 6, motor 10, shaft 11, and motor casing 12 are omitted from illustration in order to emphasize the configuration of impeller 18.

[0052] In internal space 17, the closer one gets to the side where impeller 18 is located (the side where suction port 3 is located), the more susceptible one is to the pressurization of the flowing water and air by impeller 18. That is, in internal space 17, the internal pressure tends to be higher on the upstream side (the side where suction port 3 is located) than on the downstream side (the side where discharge port 4 is located).

[0053] (Exhaust section) 1 to 7, as a characteristic configuration of the present disclosure, pump casing 2 is provided with exhaust section 20 for discharging air accumulated in internal space 17 to the outside. Exhaust section 20 is disposed at a position downstream away from the position of impeller 18.

[0054] As shown in Figs. 1 to 5, in the embodiment of the present disclosure, the exhaust section 20 is composed of two through holes 21, 21 provided in the pump casing 2. As shown in Figs. 6 and 7, the through holes 21, 21 are formed on the left and right side portions of the third casing portion 2c in a vertical cross-sectional view. Each through hole 21 penetrates the third casing portion 2c in the horizontal direction. Each through hole 21 communicates with the internal space 17. The through holes 21, 21 are line-symmetric (bilaterally symmetric) with respect to the vertical center line of the third casing portion 2c in a vertical cross-sectional view.

[0055] 1 to 5, each through hole 21 opens in a substantially circular shape. The diameter of each through hole 21 is preferably about 30 mm. This allows air accumulated in the internal space 17 to be easily exhausted to the outside, and also suppresses a decrease in pump efficiency. On the other hand, if the diameter of each through hole 21 exceeds 30 mm, there is a risk that the pump efficiency of the horizontal shaft pump will decrease.

[0056] As shown in Fig. 6, the through holes 21, 21 (exhaust section 20) are preferably disposed above the center of rotation of the impeller 18 in the third casing section 2c (pump casing 2). More preferably, the through holes 21, 21 (exhaust section 20) are disposed above the water level of the internal space 17 (e.g., WL1 shown in Figs. 5 and 6) when most of the impeller 18 is immersed in the flowing water in the internal space 17. Note that the above-mentioned "when most of the impeller 18 is immersed in the flowing water in the internal space 17" specifically refers to a state in which 80% or more of the impeller 18 is immersed in the flowing water in the internal space 17.

[0057] As shown in Fig. 7, the through holes 21, 21 (exhaust section 20) are preferably disposed above the water level of the internal space 17 when the third casing section 2c (motor casing 12) is immersed in the running water of the internal space 17 up to a position corresponding to the rotation center of the shaft 11. More preferably, the through holes 21, 21 (exhaust section 20) are disposed above the water level of the internal space 17 (e.g., WL1 shown in Figs. 5 and 7) when most of the third casing section 2c (motor casing 12) is immersed in the running water of the internal space 17. Note that the above-mentioned "when most of the motor casing 12 is immersed in the running water of the internal space 17" specifically refers to a state in which 80% or more of the motor casing 12 is immersed in the running water of the internal space 17.

[0058] [Effects of the embodiment] In the horizontal shaft pump 1, the exhaust section 20 communicates with the internal space 17 of the pump casing 2 and is disposed downstream of the position of the impeller 18 in the pump casing 2. With this configuration, as illustrated in FIG. 3, when the water level in the internal space 17 drops from WL1 to WL2, the air accumulated in the internal space 17 of the pump casing 2 is quickly exhausted from the exhaust section 20 to the outside due to the internal pressure of the internal space 17 (see arrow E shown in FIG. 3). As this exhaust continues, the air pool in the internal space 17 is eliminated by the exhaust section 20 located downstream of the position of the impeller 18, making it easier to maintain the internal space 17 filled with water. As a result, the running water in the internal space 17 is discharged from the discharge port 4 until the water level becomes low (see arrow D shown in FIG. 3). That is, the drainage capacity of the horizontal shaft pump 1 is maintained. As a result, the duration of the air-water mixed operation state is shortened, and the operation state is quickly switched to the standby operation state.

[0059] 4, in the standby operation state, the running water in the internal space 17 is not discharged from the discharge port 4, but the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20. By continuing this exhaust, the internal space 17 located behind the impeller 18 is maintained in a state filled with running water to an extent that the normal operation state can be quickly transitioned to if the water level rises (for example, water level WL2).

[0060] Furthermore, as illustrated in Fig. 5, even when the water level in the internal space 17 rises from WL2 to WL1, the air accumulated in the internal space 17 is quickly exhausted from the exhaust section 20 to the outside due to the internal pressure of the internal space 17 (see arrow E in Fig. 5). As this exhaust continues, the flowing water in the internal space 17 is filled up to the water level WL2 at which the impeller 18 is fully immersed in the flowing water. Then, when the impeller 18 is fully immersed in the flowing water in the internal space 17, the flowing water in the internal space 17 is instantly discharged from the discharge port 4 (see arrow D in Fig. 5). As a result, the duration of the air-water mixed operation state is shortened, and the operation state is quickly switched to the normal operation state.

[0061] In this manner, in the horizontal shaft pump 1 according to the embodiment of the present disclosure, the duration of the air-water mixed operation state can be shortened because the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20. As a result, the horizontal shaft pump 1 can be maintained in a usable state for a long period of time, for example, in a storm water drainage pumping station.

[0062] Moreover, it is preferable that the exhaust section 20 is disposed above the center of rotation of the impeller 18 in the pump casing 2. That is, the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20 located above the center of rotation of the impeller 18. This makes it possible to position the water level in the internal space 17 above the center of rotation of the impeller 18, for example, when the water level in the internal space 17 is rising. That is, it becomes possible to make the impeller 18 fully immersed in the running water in the internal space 17. As a result, the duration of the air-water mixed operation state is shortened, and the operation state can be quickly shifted to the normal operation state.

[0063] Furthermore, it is more preferable that the exhaust section 20 is positioned above the water level of the internal space 17 (for example, WL1 shown in Figs. 5 and 6) when most of the impeller 18 is immersed in the flowing water in the internal space 17. That is, the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20 positioned above the water level of the internal space 17 when most of the impeller 18 is immersed in the flowing water in the internal space 17. This makes it easier to maintain a state in which most of the impeller 18 is immersed in the flowing water in the internal space 17, for example, when the water level in the internal space 17 is rising. As a result, the duration of the air-water mixed operation state is shortened, and the normal operation state can be quickly transitioned to.

[0064] In addition, the exhaust section 20 is preferably disposed above the water level of the internal space 17 when the motor casing 12 is immersed in the running water of the internal space 17 up to a position corresponding to the rotation center of the shaft 11. That is, the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20 located above the water level of the internal space 17 when the motor casing 12 is immersed in the running water of the internal space 17 up to a position corresponding to the rotation center of the shaft 11. As a result, for example, when the water level of the internal space 17 is rising, at least half of the motor casing 12 is immersed in the running water of the internal space 17. As a result, the flowing water in the internal space 17 can absorb heat generated by the motor 10. In addition, the flowing water filling the internal space 17 lubricates a mechanical seal (not shown).

[0065] Furthermore, it is more preferable that the exhaust section 20 is disposed above the water level of the internal space 17 when most of the motor casing 12 is immersed in the flowing water in the internal space 17. In this way, the air accumulated in the internal space 17 is exhausted to the outside from the exhaust section 20 located above the water level of the internal space 17 when most of the motor casing 12 is immersed in the flowing water in the internal space 17. This makes it possible to immerse most of the motor casing 12 in the flowing water in the internal space 17, for example, when the water level in the internal space 17 is rising. As a result, the heat generated by the motor 10 can be received by the flowing water in the internal space 17.

[0066] Moreover, in the embodiment of the present disclosure, the exhaust section 20 is configured by through holes 21, 21 penetrating the pump casing 2. With such a simple configuration using the through holes 21, 21, the air accumulated in the internal space 17 of the pump casing 2 can be appropriately exhausted to the outside.

[0067] [First Modification of the Embodiment] In the above embodiment, the exhaust section 20 is configured to have two through holes 21, 21, but is not limited to this. For example, the exhaust section 20 may be configured as a pipe section that communicates with the internal space 17 and extends horizontally from the outer circumferential surface of the pump casing 2.

[0068] Specifically, in the first modified example shown in Fig. 8, the exhaust section 20 is formed of one cast hole 22 (pipe section) formed integrally with the pump casing 2. This cast hole 22 is formed in a side portion of the third casing section 2c (the side portion located on the right side of the paper surface of Fig. 8) in a vertical cross-sectional view. The cast hole 22 is formed in a substantially cylindrical shape extending in the horizontal direction. In this modified example, the simple configuration using the cast hole 22 (pipe section extending in the horizontal direction) makes it possible to exhaust air accumulated in the internal space 17 while guiding it horizontally from the cast hole 22 (pipe section) to the outside according to the condition of the water passage or water tank in which the horizontal shaft pump 1 is installed.

[0069] The pipe portion is not limited to the cast hole 22 shown in Fig. 8. For example, instead of the cast hole 22, a straight pipe member (not shown) may be fixed to the outer circumferential surface of the pump casing 2 so as to extend horizontally from the outer circumferential surface in communication with the through hole 21 described in the above embodiment. A plurality of cast holes 22 may be provided.

[0070] [Modification 2 of the embodiment] 9, a substantially L-shaped elbow member 23 may be fixed to the outer circumferential surface of the pump casing 2 in a state of communication with one through hole 21 similar to that described in the above embodiment. Specifically, the elbow member 23 of this modification is configured such that one end 23a is fixed to the outer circumferential surface of the pump casing 2 by, for example, welding, while the other end 23b opens upward.

[0071] In this modified example, the simple configuration using the through hole 21 and the elbow member 23 allows air that has accumulated in the internal space 17 of the pump casing 2 to be exhausted while being guided in a predetermined direction from the through hole 21 and the elbow member 23 toward the outside. In particular, in this modified example, the elbow member 23 having the other end 23b opening upward allows air that has accumulated in the internal space 17 to be appropriately exhausted while being guided upward from the through hole 21 and the elbow member 23 toward the outside according to the conditions of the water passage or water tank in which the horizontal shaft pump 1 is installed. Note that a plurality of through holes 21 and elbow members 23 may be provided.

[0072] [Modification 3 of the embodiment] As a further modification of Modification 2, the elbow member 23 may be configured as in Modification 3 shown in Fig. 10. Specifically, the elbow member 23 of this modification is configured such that one end 23a is fixed to the outer circumferential surface of the pump casing 2, while the other end 23b opens downward. With this configuration, in this modification, air that has accumulated in the internal space 17 can be appropriately exhausted while being guided downward toward the outside through the through hole 21 and the elbow member 23 according to the conditions of the water passage or water tank in which the horizontal shaft pump 1 is installed. Note that, as in Modification 2, a plurality of through holes 21 and elbow members 23 may be provided.

[0073] [Other embodiments] In the above embodiment, the exhaust section 20 is configured with two through holes 21, 21, but is not limited to this. That is, the exhaust section 20 may be configured with only one through hole 21. That is, as long as at least one through hole 21 is provided in the pump casing 2, the above-mentioned action and effect of the exhaust section 20 described in the above embodiment can be obtained.

[0074] In the above embodiment, the through holes 21, 21 (exhaust portion 20) are provided in the third casing portion 2c, but the present invention is not limited to this. That is, as long as at least one through hole 21 is provided in any one of the second to fourth casing portions 2b to 2d, the above-mentioned advantageous effects can be obtained.

[0075] The exhaust section 20 may also be configured to have three or more through holes 21. In this case, the multiple through holes 21 may be arranged at intervals from one another along the longitudinal direction (extension direction of the axis A) of the pump casing 2. In this way, the multiple through holes 21 can efficiently exhaust air accumulated in the internal space 17.

[0076] In the above embodiment, the through holes 21 penetrate the third casing portion 2c in the horizontal direction, but the present invention is not limited to this. For example, the through holes 21 may be formed to penetrate the third casing portion 2c in the thickness direction (diameter direction of the pump casing 2).

[0077] In the above embodiment, the through hole 21 is opened in a substantially circular shape, but the present invention is not limited to this. For example, the opening of the through hole 21 may be formed in a polygonal shape such as a triangle or a rectangle.

[0078] As described in the above embodiment, the internal pressure of internal space 17 tends to be higher on the upstream side (the side where suction port 3 is located) than on the downstream side (the side where discharge port 4 is located). In view of this, in order to increase the exhaust capacity of through hole 21 (exhaust section 20), through hole 21 may be disposed in the vicinity of the downstream side where impeller 18 is located (for example, first casing section 2b).

[0079] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Industrial Applicability]

[0080] The present disclosure has industrial applicability, for example, as a full-speed, full-level horizontal shaft pump that can be installed in a flowing waterway or a water tank. [Explanation of symbols]

[0081] 1: Horizontal pump 2: Pump casing 3: Intake port 4:Discharge port 5: Underwater cable 7: Rectifier plate 10:Motor 11: Shaft 12: Motor casing 17: Interior space 18: Impeller 20: Exhaust section 21:Through hole 22: Cast hole 23: Elbow component

Claims

1. A horizontal shaft pump that can be installed in a waterway or a water tank, a pump casing having an intake port located on an upstream side and an exhaust port located on a downstream side, the pump casing being provided with an internal space that connects the intake port and the exhaust port; a motor disposed downstream of the suction port in the internal space; an impeller disposed upstream of the suction port in the internal space and rotatable by being driven by the motor; The impeller is configured to discharge the flowing water drawn in from the suction port through the internal space toward the discharge port, The pump casing is provided with at least one exhaust portion that is in communication with the internal space and that exhausts air that has accumulated in the internal space to the outside, the exhaust section has at least one through hole that is disposed downstream of the position of the impeller and penetrates the pump casing, and constantly communicates the internal space with the outside, A horizontal axis pump, wherein when the water level in the internal space is decreasing, air accumulated in the internal space is discharged to the outside through the exhaust portion due to the internal pressure of the internal space.

2. 2. The horizontal shaft pump according to claim 1, The impeller is disposed so that its center of rotation coincides with the axis of the pump casing, The exhaust section is disposed above a center of rotation of the impeller in the pump casing.

3. 3. The horizontal shaft pump according to claim 2, A horizontal axis pump, wherein the exhaust portion is disposed above a water level in the internal space when 80% or more of the impeller is immersed in the flowing water in the internal space.

4. The horizontal shaft pump according to any one of claims 1 to 3, a motor casing disposed in the internal space and surrounding the entire periphery of the motor; The motor is provided with a shaft that can be rotated by driving the motor, The motor is disposed so that the center of rotation of the shaft coincides with the axis of the pump casing, A horizontal axis pump, wherein the exhaust section is positioned above the water level in the internal space when the motor casing is immersed in flowing water in the internal space up to a position corresponding to the center of rotation of the shaft.

5. 5. The horizontal shaft pump according to claim 4, A horizontal shaft pump, wherein the exhaust section is disposed above the water level in the internal space when 80% or more of the motor casing is submerged in the flowing water in the internal space.

6. The horizontal shaft pump according to any one of claims 1 to 5, The exhaust portion includes a pipe portion that communicates with the through hole and extends horizontally from an outer circumferential surface of the pump casing.

7. The horizontal shaft pump according to any one of claims 1 to 5, The exhaust portion includes a generally L-shaped elbow member that communicates with the through hole and is fixed to the pump casing.

8. 8. The horizontal shaft pump according to claim 7, A horizontal shaft pump, wherein the elbow member has one end fixed to the outer circumferential surface of the pump casing and the other end opening upward.

9. 8. The horizontal shaft pump according to claim 7, A horizontal shaft pump, wherein the elbow member has one end fixed to the outer circumferential surface of the pump casing and the other end opening downward.

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