Pumping equipment and control devices

Abstract

To reduce a running cost in the case that a submerged bearing of a horizontal shaft pump includes resin in a raw material.SOLUTION: A pump facility comprises: a spindle extending in a horizontal direction; an impeller fixed to the spindle; a pump casing in which the impeller is accommodated; a bearing casing which is arranged in the pump casing, and in which a tip part of the spindle is accommodated; a submerged bearing arranged in the bearing casing, supporting the spindle so as to be rotatable, and including resin in a raw material; water injection piping arranged in a state of penetrating the bearing casing, and supplying flushing water into a clearance between saddle faces of the spindle and the submerged bearing from the outside; a water tank communicating with the water injection piping, and arranged at a position higher than the water injection piping; a water injection control valve arranged at the water injection piping, and controlling the opening and closing of a conduit; a prime motor for driving the spindle; and a control device for controlling the water injection control valve so as to be opened during water drop or a stop step of the prime motor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to pump equipment and control devices.

Background Art

[0002] The rotating body of a pump used for pumping or draining is provided with a shaft and bearings for supporting an impeller. Ball bearings, roller bearings, etc. are used for the bearings provided in the air part (outside), and sliding bearings are used for the bearings provided inside the pump casing (in the water part). For this sliding bearing, many products that use white metal or the like to supply grease are used. However, when there are concerns such as the need for labor saving (improvement of reliability by simplification) of the grease supply machine, maintenance management and discharge of grease (treatment of discarded grease and leakage to the handling liquid), a ceramic bearing that lubricates the sliding surface with a handling liquid (self-water) without using oil (grease or lubricating oil) may be used. Ceramic bearings are brittle materials and are very hard, having the advantage of being less likely to wear even in handling liquids with poor water quality such as river water and rainwater containing a large amount of silt and dust, and having a relatively long replacement cycle.

Prior Art Documents

Patent Documents

[0003] [[ID=~]]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, while ceramics are hard, they are brittle as brittle materials and are vulnerable to impact and uneven load.

[0005] As a solution, some companies employ oil-free (self-water lubricated) bearings made from resins that are not brittle (for example, using resins as the main raw material). However, when handling fluids with poor quality, these bearings wear out faster than those made from brittle materials, resulting in shorter replacement cycles and higher running costs.

[0006] The present invention has been made in view of the above problems, and aims to provide a pump system and control device that can reduce running costs when the submersible bearing of a horizontal shaft pump contains resin as a raw material. [Means for solving the problem]

[0007] A pump system according to a first aspect of the present invention comprises: a main shaft extending horizontally; an impeller fixed to the main shaft; a pump casing housing the impeller; a bearing casing installed within the pump casing and housing the tip of the main shaft; an underwater bearing installed within the bearing casing and rotatably supporting the main shaft, and containing resin as a raw material; a water injection pipe provided so as to penetrate the bearing casing and for supplying flushing water from the outside between the sliding surfaces of the main shaft and the underwater bearing; a water tank connected to the water injection pipe and positioned higher than the water injection pipe; a water injection control valve provided in the water injection pipe and controlling the opening and closing of the pipeline; a prime mover for driving the main shaft; and a control device for controlling the opening of the water injection control valve when the water is drained or during the prime mover's shutdown process.

[0008] A pump system according to a second aspect of the present invention is a pump system according to a first aspect, further comprising an intake pipe for introducing air into the pump casing and an openable and closable vacuum breaking valve provided in the intake pipe, wherein the control to open the water injection control valve when water falls means that when the prime mover stops rotating, the water injection control valve is opened at the same time as or before or after the opening of the vacuum breaking valve.

[0009] A pump system according to a third aspect of the present invention is a pump system according to the first or second aspect, further comprising a spindle sleeve that circumferentially covers a portion of the tip of the spindle, the spindle sleeve being provided with grooves for removing silt and the like with the flushing water.

[0010] A pump system according to a fourth aspect of the present invention is a pump system according to any of the first to third aspects, comprising a detector for detecting water flow or water volume when flushing water is supplied, and the control device determines the amount of silt or the like adhering to the main shaft or the underwater bearing and / or the effect of removing silt or the like using the amount detected by the detector or the amount of change in the amount detected over time.

[0011] A fifth aspect of the present invention is a pump system according to any of the first to fourth aspects, wherein the water tank is also used as a replenishment tank for the vacuum pump for intake.

[0012] A pump system according to a sixth aspect of the present invention is a pump system according to any of the first to fifth aspects, comprising a wear detection sensor for detecting the amount of wear of the underwater bearing, and the control device notifies the underwater bearing of the replacement or the timing of replacement according to the sensing result of the wear detection sensor.

[0013] A pump system according to a seventh aspect of the present invention is a pump system according to a sixth aspect, wherein a cleaning pipe is provided for cleaning the wear amount detection sensor and / or the shaft end of the main shaft to be measured.

[0014] The pump equipment according to the eighth aspect of the present invention is the pump equipment according to any of the first to seven aspects, wherein the control device controls the water injection control valve to open simultaneously with the start of the pump stop operation in order to inject water while the main shaft is rotating.

[0015] A pump system according to the ninth aspect of the present invention is a pump system according to any of the first to seven aspects, comprising: a discharge valve on the discharge side of the pump casing; a discharge pipe communicating with the discharge side of the pump casing; an intake pipe for introducing air into the pump casing; and an openable and closable vacuum breaking valve provided in the intake pipe, wherein the control device controls the system to open the vacuum breaking valve and the discharge valve simultaneously after the prime mover has stopped, in order to rotate the main shaft by the force of water flowing back from the discharge pipe.

[0016] A pump system according to a tenth aspect of the present invention is a pump system according to any of the first to seven aspects, comprising an intake pipe for introducing air into the pump casing, and an openable and closable vacuum breaking valve provided in the intake pipe, wherein the water tank is open to the atmosphere, and the control device controls the water injection control valve to open for a first set time after the prime mover has stopped and before the vacuum breaking valve has opened.

[0017] A pump system according to an eleventh aspect of the present invention is a pump system according to any of the first to seven aspects, comprising an intake pipe for introducing air into the pump casing and an openable and closable vacuum-breaking valve provided in the intake pipe, wherein the control device controls the vacuum-breaking valve to open for a second set time after the prime mover has stopped and before the water injection control valve has opened.

[0018] A pump system according to the twelfth aspect of the present invention is a pump system according to any of the first to eleven aspects, wherein the control device controls the operation and stopping of the prime mover.

[0019] A pump system according to a thirteenth aspect of the present invention comprises a main shaft extending horizontally, an impeller fixed to the main shaft, a pump casing housing the impeller, a bearing casing installed within the pump casing and housing the tip of the main shaft, an underwater bearing installed within the bearing casing and rotatably supporting the main shaft, and containing resin as a raw material, an intake pipe that penetrates the bearing casing and is provided with one end facing the underwater bearing, and for introducing air into the pump casing, an openable and closable vacuum breaking valve provided in the intake pipe, and a control device that controls the opening of the vacuum breaking valve after the prime mover has stopped.

[0020] A control device according to a 14th aspect of the present invention is a control device used in a pump system comprising: a water injection pipe provided in a manner that penetrates the bearing casing and supplies flushing water from the outside between the sliding surfaces of the main shaft and the underwater bearing; a water tank communicating with the water injection pipe and positioned higher than the water injection pipe; and a water injection control valve provided in the water injection pipe and controlling the opening and closing of the pipeline, wherein the control device controls the water injection control valve to open when the water is drained or during the stopping process of the prime mover that drives the main shaft. [Effects of the Invention]

[0021] According to one aspect of the present invention, when the submersible bearing of a horizontal shaft pump contains resin, flushing water is supplied between the sliding surfaces of the main shaft and the submersible bearing during water drainage or engine shutdown. This flushes the inside of the submersible bearing, which may be contaminated with river water during water drainage or engine shutdown, and removes foreign matter from the inside of the submersible bearing. This reduces wear on the submersible bearing, extends the replacement cycle of the submersible bearing, and reduces running costs. According to another aspect of the present invention, when the vacuum breaking valve is opened, air is supplied near the underwater bearing, which causes the water to be agitated in a gas-liquid mixture state, resulting in a cleaning action and flushing by the air, thereby removing foreign matter from inside the underwater bearing to the outside of the bearing. [Brief explanation of the drawing]

[0022] [Figure 1] This is a schematic configuration diagram of the pump equipment according to this embodiment. [Figure 2] This is a partial cross-sectional view of the pump according to this embodiment. [Figure 3] This is a flowchart showing a first example of the control method. [Figure 4] This is a schematic diagram showing an example of the groove of the main shaft sleeve. [Figure 5] This is a diagram showing an example of the arrangement relationship of the wear amount detection sensors. [Figure 6] This is a flowchart showing a second example of the control method. [Figure 7] This is a flowchart showing a third example of the control method. [Figure 8] This is a flowchart showing a fourth example of the control method. [Figure 9] This is a flowchart showing a fifth example of the control method. [Figure 10] This is a partial cross-sectional view of the pump according to the modified example.

Mode for Carrying Out the Invention

[0023] Hereinafter, each embodiment will be described with reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters and a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0024] In addition to the above-mentioned problems, the inventors of this invention discovered the following problem: If separate equipment (e.g., a pressure pump) is installed to supply water to the underwater bearing, there are problems with initial costs and maintenance. Therefore, the inventors of this invention conceived of installing a water injection pipe to supply flushing water from the outside (specifically, for example, by pouring water) between the sliding surfaces of the main shaft and the underwater bearing, and connecting the water injection pipe to a water tank (e.g., an elevated water tank), thereby supplying flushing water (specifically, for example, water) from this water tank via the water injection pipe and the water injection pipe. As a result, the flushing water (e.g., water) directly contacts the sliding surfaces of the main shaft and the underwater bearing, thereby improving the cleaning effect.

[0025] However, even if water is added when the system is full, there is a problem that once the water supply is stopped, the system will come into contact with river water again and become contaminated. In response to this, the inventor of the present invention conceived of controlling the opening of a control valve installed in the water supply piping when the water is being drained or during the process of stopping the prime mover. This allows the inside of the underwater bearing, which has been contaminated with river water, to be flushed when the water is being drained or during the process of stopping the prime mover, removing foreign matter from the underwater bearing. Flushing continues until the water draining is complete, preventing the bearing from coming into contact with river water again and thus suppressing the accumulation of contaminated material.

[0026] Figure 1 is a schematic diagram of the pump equipment according to this embodiment. As shown in Figure 1, the pump equipment 10 comprises a control device 1, a prime mover 2, a reduction gear 3 that reduces the rotation of the prime mover 2, and a pump 4 that draws water from the suction well 7 and discharges it. Here, the control device 1 controls the operation and stopping of the pump 4 by controlling the operation and stopping of the prime mover 2. The control device 1 has, for example, a timer 11. The prime mover 2 drives the main shaft 41 of the pump 4, for example, via the reduction gear 3. The pump 4 is a horizontal shaft pump, and in this embodiment, as an example, it is a horizontal shaft axial-mixed flow pump that performs suction operation. The pump 4 is provided with a discharge valve V1.

[0027] Furthermore, the pump equipment 10 includes an intake pipe P1 provided on the pump 4, one end of which is connected to the pump casing 43 of the pump 4; a water level detector S1 provided on the intake pipe P1; an intake pipe P10 branched from the intake pipe P1 for introducing air into the pump casing; and an openable and closable vacuum breaking valve V2 provided on this intake pipe P10. Furthermore, the pumping equipment 10 includes an intake valve V3 installed in the intake pipe P1, branch pipes P11 and P12 from which the intake pipe P1 branches, a vacuum pump VP1 installed in the branch pipe P11, and a vacuum pump VP2 installed in the branch pipe P12. The discharge pipes of vacuum pumps VP1 and VP2 are connected to the intake well 7.

[0028] Furthermore, the pump equipment 10 includes an intake pipe P2 from Unit 2 that communicates with the intake pipe P1, and an intake pipe P3 from Unit 3 that communicates with the intake pipe P1. Furthermore, the pump equipment 10 includes a water tank 6, a water level gauge 61 for measuring the water level in the water tank 6, a water supply pipe P6 connected to the water tank 6, a discharge pipe P61 with one end connected to the water tank 6 and the other end connected to the suction well, a discharge pipe P62 with one end connected to the water tank 6, a branch pipe P63 branching from the discharge pipe P62 and connected to the vacuum pump VP1, and a branch pipe P64 branching from the discharge pipe P62 and connected to the vacuum pump VP2.

[0029] Furthermore, the pump equipment 10 includes an elevated water tank 5, which is an example of a water tank; a water level gauge 53 for measuring the water level of the elevated water tank 5; a water supply pipe P5 that communicates with the elevated water tank 5; a discharge pipe P51, one end of which communicates with the elevated water tank 5 and the other end of which communicates with a water intake well; a water injection pipe P4, one end of which communicates with the elevated water tank 5; a water injection pipe P41, which is branched into two from the water injection pipe P4; and a water injection pipe P42.

[0030] Furthermore, the pump equipment 10 includes a water detector S2 installed in the water injection pipe P42 and a water injection control valve V6 (hereinafter also simply referred to as the control valve) installed in the water injection pipe P42. Here, the water injection control valve V6 is, for example, an electric valve or a solenoid valve.

[0031] The water detector S2 may be a flow switch or a flow meter.

[0032] Figure 2 is a partial cross-sectional view of the pump according to this embodiment. As shown in Figure 2, the pump 4 comprises a main shaft 41 extending horizontally, an impeller 42 fixed to the main shaft 41, a pump casing 43 housing the impeller 42, and a bearing casing 44 installed inside the pump casing 43 and housing the tip of the main shaft 41.

[0033] Furthermore, the pump 4 includes a submersible bearing 45 installed within a bearing casing 44 that rotatably supports the main shaft 41 and is made of resin as a raw material, a water injection pipe 46, a water injection pipe 47, a discharge pipe 48, and an openable / closable discharge valve 49 provided on the discharge pipe 48. Here, the submersible bearing is, as an example, made primarily of resin. The water injection pipe 46 is installed so as to penetrate the bearing casing 44 and is intended to supply flushing water from the outside between the sliding surfaces of the main shaft 41 and the underwater bearing. The water injection pipe 46 is in communication with the water injection pipe P42.

[0034] The elevated water tank 5 has water injection pipes 46 and 47 connected to it and is positioned higher than the water injection pipes 46 and 47. This allows flushing water (e.g., water) from the elevated water tank 5 to be supplied between the sliding surfaces of the main shaft 41 and the underwater bearing 45 via water injection pipes P4 and P42 and water injection pipe 46 or 47.

[0035] The control device 1 controls the water injection control valve V6 to open when the water is being drained or during the stopping process of the prime mover 2. Next, specific examples of the control methods will be explained.

[0036] <Example 1 of the control method> First, we will explain a first example of the control method using Figure 3. Figure 3 is a flowchart showing a first example of the control method.

[0037] (Step S110) The control device 1 outputs a pump stop signal to the prime mover 2.

[0038] (Step S120) The prime mover 2 receives a pump stop signal and starts to stop rotating, thereby performing the pump stop operation.

[0039] (Step S130) After that, the prime mover 2 stops.

[0040] (Step S140) Next, the control device 1 controls the vacuum breaking valve V2 to open, and simultaneously with or before / after the opening of the vacuum breaking valve V2, controls the water injection control valve V6 to open.

[0041] (Step S150) Next, the control device 1 counts the time using the timer 11. Here, it is assumed that the time required to complete the draining of the water (referred to as the time required to complete the draining) is known because the time from when the pump 4 is full to when the water draining is complete has been measured in advance.

[0042] (Step S160) When the time required for the water to drain has elapsed from the start of the timer count, the water draining from pump 4 is completed.

[0043] (Step S170) When the time required for the water to drain has elapsed from the start of the timer count, the control device 1 can consider that the water draining from the pump 4 has been completed, and controls the vacuum breaking valve V2 to close and the water injection control valve V6 to close.

[0044] <Effect 1 of the first example of the control method> In this first example of the control method, the control device 1 receives a signal to stop the pump and controls the water injection control valve V6 to open when the water is released, at the same time as or before or after the vacuum breaking valve opens. This allows for control over the supply of flushing water used to remove silt and other contaminants from the underwater bearing 45, thereby suppressing wear of the underwater bearing due to silt and other contaminants, and improving reliability and maintainability.

[0045] <Effect 2 of the first example of the control method> Furthermore, when the horizontal-axis pump performing suction operation stops, the vacuum-breaking valve V2 is opened, allowing the water inside the pump to drain and shut down. When the water drains, a sudden negative pressure is created inside the pump casing 43, so opening the water injection control valve V6 creates a pressure difference greater than the height of the elevated water tank 5, ensuring that the water from the elevated water tank 5 is (sufficiently) supplied to the submersible bearing 45. Under normal conditions, only the height of the elevated water tank 5 is applied as water supply pressure. However, by utilizing the negative pressure when the system is stopped, a sufficient pressure difference can be secured. This eliminates the need to install a new high-head booster pump for water supply, allowing for the construction of a simple pump system using natural phenomena, thereby improving cost-effectiveness.

[0046] <Effect 3 of the first example of the control method> Furthermore, in pumps that handle river water, river silt and other particles flow in. Also, pump 4 is operated during rainfall, and after one operation, it may not be operated for several weeks. When the pump stops and becomes airborne, the silt and other particles that adhere to the submersible bearing 45 solidify, making it difficult to clean (remove). In contrast, in the first example of the control method described above, it can be removed immediately after the pump starts up, thus improving the removal efficiency.

[0047] <Effect 4 of the first example of the control method> Furthermore, if the handling fluid contains seawater, corrosion of the sleeve sliding surface of the main shaft 41 can be prevented by injecting water and washing it after stopping operation.

[0048] <Preferred Embodiment> It is preferable that the water injection pipe 46 be positioned approximately in the center in the longitudinal direction of the main shaft 41 of the submersible bearing 45 so that the water injection reaches the entire submersible bearing 45. Furthermore, the underwater bearing 45 may be composed of a composite material of fluororesin, aromatic polyether ketone, carbon fiber, and unavoidable impurities, as disclosed in, for example, Patent Document 3 (Japanese Patent Application Publication No. 2013-194769).

[0049] <Other Embodiments 1> The water injection pipe may be provided approximately in the center of the underwater bearing 45 in the axial direction, as shown by the water injection pipe 46 in Figure 2; it may be provided at the end of the underwater bearing 45, as shown by the water injection pipe 47 in Figure 2; or it may be provided at both the approximately center and the end of the underwater bearing 45 in the axial direction.

[0050] <Other Embodiments 2> As shown in Figure 2, the water injection pipe 47 may be routed to the inside of the pump via an unused grease supply line to reach the submersible bearing 45.

[0051] <Other Embodiments 3> As shown in Figure 2, the water injection pipe 46 may have a route through which it enters the pump, passing through the connection port 411 of the intake pipe used to create a vacuum, and reaching the submersible bearing 45.

[0052] <Other Embodiments 4> As shown in Figure 2, a discharge pipe 48 is provided for discharging the wastewater after cleaning. In this way, foreign matter such as silt removed by cleaning the submersible bearing 45 is discharged through a hole in the bearing casing 44, and the discharge pipe 48 may be installed so that it does not accumulate inside the pump casing 43.

[0053] <Drainage channel processing for flushing water> Figure 4 is a schematic diagram showing an example of grooves in a spindle sleeve. As shown in Figure 4, the spindle 41 is provided with a spindle sleeve 421 that covers a portion of the tip of the spindle 41 in the circumferential direction. As shown in Figure 4, the spindle sleeve 421 is provided with circumferential grooves 422 and 423, and axial grooves 424, 425, 426 and 427. As described above, the spindle sleeve 421 is provided with grooves for removing silt and other debris with flushing water. This allows for the reliable removal (cleaning) of silt and other debris that have entered the underwater bearing 45 and then discharged outside the underwater bearing 45, thereby improving the efficiency of removal (cleaning) and enhancing the reliability (lifespan) of the bearing.

[0054] <Other Embodiments> The underwater bearing 45, which contains resin as a raw material, may have grooves, or the grooves may be provided on the spindle sleeve 421 side facing the underwater bearing 45. In addition, there is one or more grooves, but it is preferable to have multiple grooves.

[0055] When grooves are provided in the underwater bearing 45, there may be one or more grooves along the axial direction, one or more grooves perpendicular to the axial direction (circumferential direction), or both. Furthermore, there may be no grooves at all.

[0056] The groove on the spindle sleeve 421 side may have one or more grooves parallel to the axial direction, one or more grooves perpendicular to the axial direction (circumferential direction), or both. Alternatively, it may not have any grooves at all.

[0057] <Checking the silt condition by checking the water flow rate> Water detector S2 is an example of a detector used to detect water flow or volume when flushing water is supplied. The control device 1 uses the amount detected by the detector (in this case, a water detector S2) or the amount of change in the detected amount over time to determine the amount of silt or the like adhering to the main shaft or underwater bearing 45 and / or the effect of removing the silt or the like.

[0058] <Effect 1> Here, the silt condition is judged from the perspective of how easily water flows in. This allows for an accurate assessment of the condition of the underwater bearing 45, whose internal structure is not visible, and can be used as an indicator for maintenance and management. Furthermore, if the amount of silt and other materials is small (note that even with the same pump, the amount of silt and other materials contained will differ depending on the river conditions, rainfall, and water level), the amount of water supplied can be optimized (reducing water costs) by considering the removal of silt and other materials as having occurred once a specified amount of water has flowed through the system, and then stopping the water supply after confirming the removal of silt and other materials.

[0059] <Effect 2> Furthermore, by comparing the data with that from when pump 4 was newly installed, it is possible to measure the progression of wear on the underwater bearings, thereby improving reliability and maintainability.

[0060] <Other Embodiments> The detector used to detect the water flow or volume when flushing water is supplied may be a water detector S2 (for example, a flow meter or flow switch) installed in the water injection pipe, or a pressure gauge installed in the water injection piping or a water level gauge 53 installed in the elevated water tank 5. In the case of a pressure gauge, the water flow or volume may be calculated from the pressure, or in the case of a water level gauge 53, the water flow or volume may be calculated from the change in water level.

[0061] <Water supply from the water tank 6 for the vacuum pump> Although the elevated water tank 5 is shown as an example of a water tank for water injection, the water tank for water injection may also be used in conjunction with the replenishment tank 6 for the vacuum pump for air intake. By using the water tank for water injection as a replenishment tank for the vacuum pump, the equipment becomes simpler, improving economic efficiency and maintainability.

[0062] <Other Embodiments> In this case, it is preferable to install the water tank 6 at an appropriate height to increase the water supply pressure of the submersible bearing 45. If the pumping station (building structure) is low, a booster pump may be installed instead. As mentioned above, it is preferable not to install a pressure pump, but if it is not possible to secure water supply pressure due to constraints of the building structure, a small pressure pump may be installed. Furthermore, since the cleaning is performed when the pump is stopped (when there is negative pressure inside the pump), a pump with a lower head (pressure) than a pressure pump designed for normal cleaning can be selected, which has an economic benefit.

[0063] <In combination with wear detection sensors> Figure 5 shows an example of the arrangement of wear detection sensors. As shown in Figure 5, the pump equipment may be equipped with a wear detection sensor 50 that detects the amount of wear on the underwater bearing, for example, near the underwater bearing. In this case, the control device 1 may notify the user of the replacement of the underwater bearing 45 or the timing of replacement, depending on the sensing result of the wear detection sensor 50. For example, if the wear detection sensor 50 is a gap sensor, the user may notify the user of the replacement of the underwater bearing 45 when the underwater bearing 45 is worn down and the distance (gap) between the inner surface of the underwater bearing 45 and the outer surface of the main shaft 41 exceeds a threshold, or the user may notify the user of replacement after a set period (for example, one month). By using wear detection sensors 50 in combination in this way, reliability can be improved.

[0064] In cases where a gap sensor is used as the wear amount detection sensor 50, the measured value may not show the true value if silt or other substances are attached. To address this, a cleaning pipe may be provided for cleaning the wear amount detection sensor 50 and / or the shaft end of the spindle 41 that is being measured.

[0065] Specifically, as shown in Figure 5, for example, a sensor cleaning pipe 51 for cleaning the wear amount detection sensor 50 may be provided, and the sensor cleaning pipe 51 may be in communication with the water injection pipe P41. Furthermore, Figure 5 shows the area 431 to be cleaned at the end of the main shaft 41. As shown in Figure 5, one or more shaft end cleaning pipes 52 may be provided so that the area 431 to be cleaned at the end of the shaft can be cleaned, and the shaft end cleaning pipes 52 may be connected to the water injection pipe P41.

[0066] As described above, by providing means to remove silt and other particles such as the sensor cleaning pipe 51 and / or the shaft end cleaning pipe 52, reliable measurement and detection by the wear amount detection sensor 50 becomes possible.

[0067] Furthermore, the ends of the sensor cleaning pipe 51 and the shaft end cleaning pipe 52 may be tapered. This can increase the flow rate of the cleaning water and improve the cleaning effect.

[0068] <Second example of control method: Water is injected while the spindle is rotating>

[0069] Figure 6 is a flowchart showing a second example of the control method. (Step S210) The control device 1 outputs a pump stop signal to the prime mover 2.

[0070] (Step S220) The prime mover 2 receives a pump stop signal and begins to stop rotating, thereby performing the pump stop operation. Simultaneously with the start of this pump stop operation, the control device 1 controls the water injection control valve V6 to open.

[0071] (Step S230) After that, engine 2 stops.

[0072] (Step S240) Next, the control device 1 controls the opening of the vacuum breaking valve V2.

[0073] (Step S250) Next, the control device 1 counts the time using the timer 11. Here, it is assumed that the time required to complete the draining of the water (referred to as the time required to complete the draining) is known because the time from when the pump 4 is full to when the water draining is complete has been measured in advance.

[0074] (Step S260) When the time required for the water drainage to be completed has elapsed since the timer started counting, the water drainage from pump 4 is completed.

[0075] (Step S270) When the time required for the water to drain has elapsed from the start of the timer count, the control device 1 can consider that the water draining from the pump 4 has been completed, and controls the vacuum breaking valve V2 to close and the water injection control valve V6 to close.

[0076] Thus, in order to inject water while the main shaft 41 is rotating, the control device 1 controls the water injection control valve V6 to open at the same time as the pump stop operation begins.

[0077] When the spindle 41 is stationary, there are areas on the surface where the underwater bearing 45, which contains resin as a raw material, and the spindle sleeve 421 are in contact that are not reached by the water being injected. Therefore, by rotating the spindle 41, the entire surface can be exposed to water and cleaned. Furthermore, by injecting water while the spindle is rotating, a high cleaning effect can be expected as the surface of the spindle 41, where silt and other deposits may be attached, slides against the inner surface of the underwater bearing 45.

[0078] In the case of a mixed-flow pump, after the pump stop signal is given, water can be injected while the rotating body is still rotating (for several minutes) during the closing operation of the discharge valve.

[0079] In the case of an axial flow pump, the prime mover stops immediately after the pump stop signal is given, but the main shaft 41 continues to rotate due to inertia, so water can be injected while the main shaft 41 is rotating during that time (a few seconds).

[0080] <Third example of a control method> The control device 1 may also be controlled to open the vacuum breaking valve V2 and the discharge valve V1 simultaneously after the prime mover 2 stops, in order to rotate the main shaft 41 by the force of water flowing back from the discharge pipe (not shown). Here, the discharge pipe is a pipe that communicates with the discharge side of the pump casing 43.

[0081] An example of this control method will be explained using Figure 7. Figure 7 is a flowchart showing a third example of the control method. (Step S310) The control device 1 outputs a pump stop signal to the prime mover 2.

[0082] (Step S320) After that, the prime mover 2 stops.

[0083] (Step S330) Next, the control device 1 controls the vacuum breaking valve V2 to open, the discharge valve V1 to open, and the water injection control valve V6 to open.

[0084] (Step S340) Next, the control device 1 counts the time using the timer 11. Here, it is assumed that the time required to complete the draining of the water (referred to as the time required to complete the draining) is known because the time from when the pump 4 is full to when the water draining is complete has been measured in advance.

[0085] (Step S350) When the time required for the water to drain has elapsed from the start of the timer count, the water draining from pump 4 is completed.

[0086] (Step S360) When the time required for the water to drain has elapsed from the start of the timer count, the control device 1 can consider that the water draining from the pump 4 has been completed, and so it controls the vacuum breaking valve V2 to close, the water injection control valve V6 to close, and the discharge valve V1 to close.

[0087] <Fourth example of control method: After the pump stops, open the water injection control valve when the water level is full.> Furthermore, the control device 1 may be controlled to open the water injection control valve V6 for a first set time after the prime mover 2 has stopped and before the vacuum breaking valve V2 has opened. The elevated water tank 5 is open to the atmosphere. As a result, the negative pressure inside the pump is highest when the tank is full of water, creating a pressure difference greater than the height of the elevated water tank 5, and the water from the elevated water tank 5 is supplied to the submersible bearing 45.

[0088] An example of this control method will be explained using Figure 8. Figure 8 is a flowchart showing a fourth example of the control method. (Step S410) The control device 1 outputs a pump stop signal to the prime mover 2.

[0089] (Step S420) The prime mover 2 receives a pump stop signal and starts to stop rotating, thereby performing the pump stop operation.

[0090] (Step S430) After that, the prime mover 2 stops.

[0091] (Step S440) Next, the control device 1 controls the water injection control valve V6 to open.

[0092] (Step S450) Next, the control device 1 counts the time using the timer 11.

[0093] (Step S460) Next, the control device 1 controls the vacuum release valve V2 to open when the first set time has elapsed since the timer started counting.

[0094] (Step S470) Next, the control device 1 continues to count time using the timer 11. Here, it is assumed that the time required to complete the draining of the water (referred to as the time required to complete the draining) is known because the time from when the pump 4 is full to when the water draining is complete has been measured in advance.

[0095] (Step S480) When the time required for the water drainage to be completed has elapsed since opening the vacuum breaking valve V2, the water drainage from pump 4 is completed.

[0096] (Step S490) When the control device 1 determines that the time required for the water to drain has elapsed since the vacuum breaking valve V2 was opened by the timer 11, it can consider that the water draining from the pump 4 has been completed, and therefore controls the vacuum breaking valve V2 to close and the water injection control valve V6 to close.

[0097] <Example 5 of the control method: Open the vacuum breaking valve before opening the water injection control valve> Furthermore, the control device 1 may be controlled to open the vacuum breaking valve V2 for a second set time after the prime mover 2 has stopped and before the water injection control valve V6 has opened. When the vacuum breaking valve V2 is opened, the air supplied into the pump 4 to drain the water passes through the submersible bearing 45. This allows for a cleaning action by agitating the water in a gas-liquid mixture state, and flushing with air to remove foreign matter from inside the submersible bearing 45 to the outside.

[0098] An example of this control method will be explained using Figure 9. Figure 9 is a flowchart showing a fifth example of the control method. (Step S510) The control device 1 outputs a pump stop signal to the prime mover 2.

[0099] (Step S520) The prime mover 2 receives a pump stop signal and starts to stop rotating, thereby performing the pump stop operation.

[0100] (Step S530) After that, the prime mover 2 stops.

[0101] (Step S540) Next, the control device 1 controls the opening of the vacuum breaking valve V2.

[0102] (Step S550) Next, the control device 1 counts the time using the timer 11.

[0103] (Step S560) Next, the control device 1 controls the water injection control valve V6 to open when the second set time has elapsed since the timer started counting.

[0104] (Step S570) Next, the control device 1 continues to count time using the timer 11. Here, it is assumed that the time required to complete the draining of the water (referred to as the time required to complete the draining) is known because the time from when the pump 4 is full to when the water draining is complete has been measured in advance.

[0105] (Step S580) When the time required for the water to drain has elapsed since opening the vacuum breaking valve V2, the water draining from pump 4 is completed.

[0106] (Step S590) When the control device 1 determines that the time required for the water to drain has elapsed since the vacuum breaking valve V2 was opened by the timer 11, it can consider that the water draining from the pump 4 has been completed, and therefore controls the vacuum breaking valve V2 to close and the water injection control valve V6 to close.

[0107] As described above, the pump equipment according to this embodiment comprises a main shaft extending horizontally, an impeller fixed to the main shaft, a pump casing housing the impeller, a bearing casing installed inside the pump casing and housing the tip of the main shaft, an underwater bearing installed inside the bearing casing that rotatably supports the main shaft and contains resin as a raw material, a water injection pipe provided so as to penetrate the bearing casing and for supplying flushing water from the outside between the sliding surfaces of the main shaft and the underwater bearing, a water tank through which the water injection pipe is connected and located at a higher position than the water injection pipe, a water injection control valve provided in the water injection pipe and controlling the opening and closing of the pipeline, a prime mover that drives the main shaft, and a control device that controls the opening of the water injection control valve when the water is drained or during the prime mover's stopping process.

[0108] With this configuration, when the submersible bearing of the pump 4 contains resin, liquid flushing water is supplied between the sliding surfaces of the main shaft and the submersible bearing during water drainage or engine shutdown. This flushes the inside of the submersible bearing, which may be contaminated with river water during water drainage or engine shutdown, and removes foreign matter from the inside of the submersible bearing. This reduces wear on the submersible bearing, extends the replacement cycle of the submersible bearing, and reduces running costs.

[0109] In this embodiment, the water injection control valve V6 is described as being provided in the water injection pipe P4, but it is not limited to this, and the water injection control valve V6 may also be provided in the water injection pipes 46 and 47.

[0110] <Variation> As another modification, one or more intake pipes (including the lower one) may be connected to the submersible bearing 45. In this case, the intake pipes may be connected and the vacuum breaking valve V2 may be opened to allow air into the bearing casing 44 of the pump 4. This supplies air to the vicinity of the submersible bearing 45, which in turn causes the water to be agitated in a gas-liquid mixture, resulting in a cleaning action and flushing by the air, thereby removing foreign matter from inside the submersible bearing 45 to the outside.

[0111] A specific example of this modified form will be explained using Figure 10. As shown in Figure 10, this is a partial cross-sectional view of the pump according to the modified form. As shown in Figure 10, intake pipes 61, 62, and 63 are provided so that one end faces the underwater bearing 45 while penetrating the bearing casing, and these intake pipes 61, 62, and 63 are in communication with intake pipe P1. As a result, when the vacuum breaking valve V2 is opened, air is supplied to the vicinity of the underwater bearing 45 through intake pipe P1 and intake pipes 61, 62, and 63.

[0112] The modified pump equipment described above comprises a main shaft extending horizontally, an impeller fixed to the main shaft, a pump casing housing the impeller, a bearing casing installed inside the pump casing and housing the tip of the main shaft, an underwater bearing installed inside the bearing casing that rotatably supports the main shaft and contains resin as a raw material, an intake pipe that penetrates the bearing casing and is provided with one end facing the underwater bearing and for introducing air into the pump casing, an openable and closable vacuum breaking valve provided in the intake pipe, and a control device that controls the opening of the vacuum breaking valve after the prime mover has stopped.

[0113] With this configuration, when the vacuum breaking valve is opened, air is supplied near the underwater bearing, which causes the water to be agitated in a gas-liquid mixture, resulting in a cleaning action and flushing by the air, thereby removing foreign matter from inside the underwater bearing 45 to the outside of the underwater bearing 45.

[0114] As described above, the present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Moreover, components from different embodiments may be appropriately combined. [Explanation of Symbols]

[0115] 1 Control device 10 Pumping equipment 11 Timer 2. Engine 3 Reducer 4 pumps 41 Spindle 411 connection ports 42 Impeller 421 Main shaft sleeve 422, 423, 424, 425, 426, 427 groove 43 Pump casing 431 Cleaning area 44 Bearing casing 45 Underwater bearings 46, 47 Water injection piping 48 Discharge pipe 49. Discharge valve 5 Elevated water tank 50 Wear amount detection sensor 51 Piping for sensor cleaning 52 Piping for cleaning shaft ends 53 Water level gauge 6 Water tank 61 Water level gauge 7 Water absorption well V2 Vacuum Breaking Valve V6 Water Injection Control Valve

Claims

1. The main shaft extends horizontally, An impeller fixed to the main shaft, A pump casing in which the impeller is housed, A bearing casing installed inside the pump casing and housing the tip of the main shaft, An underwater bearing installed within the bearing casing, which rotatably supports the main shaft and whose material is resin, A water injection pipe is provided that penetrates the bearing casing and supplies flushing water from the outside between the sliding surfaces of the main shaft and the underwater bearing, A water tank, through which the aforementioned water injection pipe is connected and located at a higher position than the aforementioned water injection pipe, A water injection control valve provided in the water injection piping and controlling the opening and closing of the pipeline, A prime mover that drives the main shaft, A control device that controls the water injection control valve to open when water is being released or during the process of stopping the prime mover, Pumping equipment equipped with the following features.

2. An intake pipe for introducing air into the pump casing, The intake piping is equipped with an openable and closable vacuum breaking valve, Controlling the water injection control valve to open when the water falls means that, when the prime mover stops rotating, the water injection control valve is opened at the same time as or before or after the vacuum breaking valve is opened. The pumping equipment according to claim 1.

3. The spindle sleeve further covers a portion of the tip of the spindle in the circumferential direction, The spindle sleeve is provided with grooves for removing silt with the flushing water. The pumping equipment according to claim 1 or 2.

4. The system includes a detector for detecting the water flow or volume when the flushing water is supplied, The control device uses the amount detected by the detector or the amount of change in the detected amount over time to determine the amount of silt adhering to the main shaft or the underwater bearing and / or the silt removal effect. The pumping equipment according to claim 1.

5. The aforementioned water tank was also used as a replenishment tank for the vacuum pump used for air intake. The pumping equipment according to claim 1.

6. The underwater bearing is equipped with a wear detection sensor for detecting the amount of wear, The control device notifies the underwater bearing of the replacement or the timing of its replacement, in accordance with the sensing results of the wear amount detection sensor. The pumping equipment according to claim 1.

7. A cleaning pipe is provided for cleaning the wear amount detection sensor and / or the shaft end of the main shaft to be measured. The pumping equipment according to claim 6.

8. The control device controls the water injection control valve to open simultaneously with the start of the pump stop operation in order to inject water while the main shaft is rotating. The pumping equipment according to claim 1.

9. A discharge valve is provided on the discharge side of the pump casing, A discharge pipe communicating with the discharge side of the pump casing, An intake pipe for introducing air into the pump casing, A vacuum-breaking valve that can be opened and closed is provided in the intake piping, Equipped with, The control device controls the opening of the vacuum breaking valve and the discharge valve simultaneously after the prime mover stops, in order to rotate the main shaft by the force of the water flowing back from the discharge pipe. The pumping equipment according to claim 1.

10. An intake pipe for introducing air into the pump casing, A vacuum-breaking valve that can be opened and closed is provided in the intake piping, Equipped with, The aforementioned water tank is open to the atmosphere, The control device controls the water injection control valve to open for a first set time after the prime mover has stopped and before the vacuum release valve has opened. The pumping equipment according to claim 1.

11. An intake pipe for introducing air into the pump casing, A vacuum-breaking valve that can be opened and closed is provided in the intake piping, Equipped with, The control device controls the opening of the vacuum release valve for a second set time after the prime mover has stopped and before the water injection control valve has opened. The pumping equipment according to claim 1.

12. The control device controls the operation and stopping of the prime mover. The pumping equipment according to claim 1.

13. A water injection pipe is provided that penetrates the bearing casing and supplies flushing water from the outside between the sliding surfaces of the main shaft and the underwater bearing, A control device used in a pump system comprising a water tank that is in communication with the water injection pipe and is located at a higher position than the water injection pipe, and a water injection control valve provided in the water injection pipe and controlling the opening and closing of the pipeline, A control device that controls the water injection control valve to open when water is being released or during the process of stopping the prime mover that drives the main shaft.

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