JP2022169190A - Submerged bearing structure, vertical shaft pump, pump system, and lubricating liquid supply method - Google Patents

Abstract

To provide a submerged bearing structure for a vertical shaft pump which supplies a liquid to a space between a bearing and a shaft sleeve during an initial operation to prevent the bearing and the shaft sleeve from operating in a dry state.SOLUTION: A submerged bearing structure supports a rotary shaft attached with an impeller of a vertical shaft pump and includes: a submerged bearing member which rotatably supports the rotary shaft; and a protection pipe having an outer wall to which the submerged bearing member is fixed. The protection pipe has an inner wall provided at the inner side of the outer wall. The outer wall and the inner wall define a liquid supply receiving part having a first opening which may receive a lubricating liquid for the submerged bearing member from above. The liquid supply receiving part is disposed above the submerged bearing member. The inner wall has a second opening which allows flow of the lubricating liquid discharged from the liquid supply receiving part.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a submersible bearing structure for a vertical shaft pump that pumps up liquid such as river water and wastewater. More particularly, the present invention relates to a submersible bearing structure capable of preventing the bearings and shaft sleeves that support the rotary shaft from operating in a dry state during initial operation such as startup in a preceding standby operation type vertical shaft pump. The present invention further relates to a vertical axis pump, a pump system and a lubricating liquid supply method including a submersible bearing structure.

An example of the background art will be described with respect to recent standby operation type vertical shaft pumps. In recent years, due to the progress of urbanization, the reduction of green areas and the expansion of concrete or asphalt road surfaces are progressing. As a result, the heat island phenomenon occurs, and localized torrential downpours called so-called guerrilla downpours frequently occur in urban areas. On a concrete or asphalted road surface, a large amount of localized rainfall is directly led to the waterway without being absorbed into the ground. As a result, a large amount of rainwater flows into the pumping station in a short period of time.

A large amount of rainwater brought by such frequent torrential rains needs to be quickly drained. Therefore, a vertical shaft pump installed at a drainage pump station is subjected to a preliminary standby operation in which the pump is started in advance before rainwater reaches the drainage pump station. As a result, it is possible to prevent flood damage due to delay in starting the pump. Specifically, in the preceding standby operation, the pump is operated from a low water level before the water level in the suction water tank reaches a level at which pumping operation can be performed. Therefore, until the water level in the suction water tank reaches the pumping level, the pump is operated without pumping (hereinafter referred to as "dry operation"). If there is a protective tube, water is supplied to the bearing that supports the rotary shaft (in other words, the main shaft) of the pump and the shaft sleeve of the rotary shaft, so that the bearing and shaft sleeve are kept wet.

In some vertical shaft pumps that are in standby mode, a protection tube system is employed in which the entire rotating shaft is covered with a protection tube so as to include rubber bearings. In the protection tube method, water is supplied into the protection tube from an elevated water tank or the like. Water can be circulated between an elevated water tank or the like and the protection pipe. Thus, water can be supplied to the bearings and bearing sleeves even during dry running.

In the above-described vertical shaft pump with a protective pipe, there may be a case where the protective pipe is not supplied with water due to a power outage or the like or a failure of the pump connected to the elevated water tank. If the pump is operated without water supplied to the protective tube, the rubber bearings will be damaged by friction. Therefore, conventionally, when water is not supplied to the protection pipe, the operation of the pump is stopped and inspection is performed. That is, the conventional vertical shaft pump with a protective tube has a problem that the main pump cannot be operated due to the failure of the auxiliary machine.

As described above, in the protective tube system, since there are many accessories such as a water supply pump, the reliability of the equipment is lowered. Therefore, it is desirable to simplify the mechanism for injecting water into the protective tube.

During air operation of vertical shaft pumps, the bearings and shaft sleeves slide in the atmosphere under conditions of high friction. In particular, among the vertical shaft pumps, the pre-standby operation pumps require atmospheric operation before pumping is started and the bearings are lubricated with water. In order to enable the pump to operate in the air while the bearings remain dry, it is conceivable to use, for example, ceramic or resin for the underwater bearings and cemented carbide or thermal spray coating for the shaft sleeve. However, if the bearings and shaft sleeve are dry during operation of the pump, the high friction will increase the temperature of the bearings and may exceed the temperature limits of the bearings themselves or the materials surrounding the bearings. Also, it is necessary to use a special resin or ceramic with a low coefficient of friction so as to suppress the effects of friction.

For example, techniques described below have been proposed so as to eliminate such material or design limitations.

Specifically, Japanese Patent Laying-Open No. 2000-2190 (Patent Document 1) discloses a bearing member housed in a bearing casing and a shaft sleeve attached to a main shaft and in sliding contact with the bearing member. A slide bearing device for a vertical shaft pump is disclosed, which is configured such that a bottomed annular water reservoir is provided in the upper portion thereof with an opening through which pumped water can flow in and out, and a bearing member is submerged in the bottomed annular water reservoir.

In JP-A-2000-266042 (Patent Document 2), an annular hard bearing member, a shaft sleeve attached to a main shaft and in sliding contact with the bearing member, and an annular hard bearing member are fitted and arranged on the outer periphery. a metal ring-shaped back metal, a ring-shaped cushioning member fitted on the back metal and arranged on the outer periphery, and a metal ring-shaped shell fitted on the back metal and arranged on the periphery, the back metal describes a plain bearing device for a vertical shaft pump provided with an annular reservoir of concave cross-section having an upper end opening capable of storing pumped water.

Japanese Patent Application Laid-Open No. 5-44689 (Patent Document 3) discloses a ceramic shaft back comprising a ceramic bearing made of porous SiC impregnated with lubricating oil, a sleeve attached to a main shaft and in sliding contact with the ceramic bearing, and a ceramic bearing. A ceramic shaft cushioning material supported via a metal is provided, a gap is formed in the surfaces where the ceramic bearing and the ceramic shaft back metal contact each other, and oil or water is supplied to the gap through a pipe. A sump pump bearing construction is described.

Japanese Patent Application Laid-Open No. 2017-166423 (Patent Document 4) describes a vertical shaft pump equipped with a cyclone separator that filters part of the water pumped by the pump, a flow meter for reliably sending the purified water to the submersible bearing, and a differential pressure gauge. It is

In the technique described in Patent Document 1, a shaft sleeve that rotates integrally with a main shaft is provided with a bottomed annular water reservoir provided with an opening through which pumped water can flow in and out. It is difficult to secure the necessary amount of water to submerge the bearing member in the water reservoir. There is a problem that it is difficult to ensure In addition, there is a problem that sand and mud contained in the pumped water accumulate in the water reservoir and damage the sliding portion (in other words, the sliding contact surface) between the bearing member and the shaft sleeve.

In the technique described in Patent Document 2, the back metal is provided with an annular water storage portion having a concave cross-section having an upper end opening capable of storing pumped water, and pumped water is stored in the water storage portion, and the water cooling action and water storage of this stored water are performed. Since the back metal is cooled by the cooling effect of the vaporization heat when it evaporates, and the bearing member is cooled via the back metal, the sliding part between the bearing member and the shaft sleeve is not directly cooled with water. , there is a problem that it cannot be sufficiently cooled. Moreover, as in Patent Document 1, water evaporates due to the frictional heat of the bearing when the pump is started, so there is a problem that it is difficult to secure the necessary amount of water.

In the technique described in Patent Document 3, a space is formed in the surfaces where the ceramic bearing and the ceramic shaft back metal contact each other, and oil or water is supplied to the space to remove the oil or water in the space. Since the sliding surface of the bearing is lubricated by exuding through the pores of SiC to the sliding surface of the bearing, the sliding portion between the bearing and the sleeve is not directly cooled with water, so there is a problem that it cannot be sufficiently cooled. There is

In the technique described in Patent Document 4, the cyclone separator cannot remove minute foreign matter, and the submerged bearing at the water supply destination wears out early, so there is a possibility that the pump cannot be operated.

JP-A-2000-2190 JP-A-2000-266042 JP-A-5-44689 JP 2017-166423 A

One embodiment of the present invention has been devised in view of the above circumstances, and prevents the bearing and shaft sleeve from operating in a dry state by supplying lubricating liquid between the bearing and the shaft sleeve during initial operation. It is an object of the present invention to provide a submersible bearing structure for a vertical shaft pump and a vertical shaft pump including the same. Another object of an embodiment of the present invention is to provide a pump system including the vertical shaft pump. Another object of an embodiment of the present invention is to provide a method of supplying lubricating liquid in the above pump system.

According to one embodiment of the present invention, there is provided a submersible bearing structure for supporting a rotating shaft to which an impeller of a vertical shaft pump is attached, wherein a submersible bearing member for rotatably supporting the rotating shaft and a submersible bearing member are fixed. a protective tube having an outer wall, the protective tube having an inner wall provided inside the outer wall, the outer wall and the inner wall defining a first opening capable of receiving a lubricating liquid for the underwater bearing member from above. A fluid receptacle is defined with a fluid receptacle, the fluid receptacle being positioned above the underwater bearing member, the inner wall defining a second opening for permitting the flow of lubricating fluid out of the fluid receptacle. A submersible bearing structure is provided, comprising:

It is a mimetic diagram showing the whole vertical axis pump outline by one embodiment of the present invention. It is a sectional view showing an example of underwater bearing structure by one embodiment of the present invention. FIG. 4 is a cross-sectional view showing another example of the underwater bearing structure according to one embodiment of the present invention; FIG. 4 is a cross-sectional view showing another example of the underwater bearing structure according to one embodiment of the present invention; FIG. 5 is a lateral cross-sectional view of the bearing shown in FIG. 4; It is a mimetic diagram showing the whole pump system outline by one embodiment of the present invention. FIG. 7 is a schematic partial view of the outlet conduit shown in FIG. 6;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description is merely an example, and is not intended to limit the technical scope of the present invention to the following embodiments. In addition, in the drawings, the same or corresponding components are denoted by the same reference numerals, and redundant explanations are omitted. In the following description, terms indicating directions such as "up" and "down" mean directions in the installation state of the vertical shaft pump shown in FIG. 1 and the like.

FIG. 1 is a diagram showing an overall outline of a vertical shaft pump 100 according to one embodiment of the present invention. The vertical shaft pump 100 includes a rotating shaft 101 extending in the vertical direction, an impeller 102 attached to the lower end of the rotating shaft 101, and a driving machine (not shown) provided at the upper end of the rotating shaft 101 to rotationally drive the rotating shaft 101. And prepare. The vertical shaft pump 100 is a pump that pumps water upward through a pump casing 108 by rotating an impeller 102 .

Further, the vertical shaft pump 100 is a preceding standby operation type pump. In the preceding standby operation, first, the impeller 102 starts to rotate in the air before the impeller 102 is submerged (in-air operation) based on rainfall information and the like regardless of the suction water level. When the water level rises to the position of the impeller 102, the operating state of the vertical shaft pump 100 changes from the operation (air-water agitating operation) in which the impeller 102 agitates the liquid handled (in other words, the liquid transferred by the vertical shaft pump 100). After the air supplied from the air inlet is sucked in together with the liquid to be handled, the liquid volume is gradually increased (air-water mixed operation), and then the liquid to be handled is discharged at the rated flow rate (steady-state operation). do.

The vertical shaft pump 100 also includes a substantially cylindrical pump casing 108 surrounding the rotating shaft 101 , the impeller 102 and the guide vanes 103 . The guide vanes 103 are fixed to the inner peripheral surface of the pump casing 108 and support a protective tube 122 which will be described later. Further, the guide vanes 103 convert the swirl component of the water flow pumped by the impeller 102 into a vertically upward component.

A pump casing 108 may include a suction bell 104 forming a pump inlet, and a discharge bowl 105 containing guide vanes 103 and bearing members 120A. The suction bell 104 is formed in a bellmouth shape. The discharge bowl 105 is formed in a substantially cylindrical shape so as to surround the guide vanes 103, and is formed such that the diameter of the cylinder expands upward along the extension direction of the rotating shaft 101 and then contracts. there is

The pump casing 108 may also include a suspension tube 106 positioned above the discharge bowl 105 and extending to a desired height. The suspension tube 106 is formed in a cylindrical shape surrounding the rotating shaft 101 . The liquid handled by the vertical shaft pump 100 is pumped up through the suspension pipe 106 . Pump casing 108 may also include a discharge elbow 107 connected to suspension tube 106 . Discharge elbow 107 is formed to extend vertically along axis of rotation 101 and then turn substantially horizontally. Accordingly, the pumped handling liquid is redirected substantially horizontally by the discharge elbow 107 . The suction bell 104 , the discharge bowl 105 , the hanging pipe 106 and the discharge elbow 107 are appropriately connected by flanges to form a pump casing 108 .

The vertical shaft pump 100 has a submersible bearing structure that rotatably supports a rotating shaft 101 . The underwater bearing structure includes an underwater bearing member 120 that supports the rotating shaft 101 . In this embodiment, two underwater bearing members (hereinafter referred to as bearing members) 120A and 120B are provided. However, in vertical shaft pump 100, the number of bearing members 120 is not particularly limited.

The underwater bearing structure comprises a protection tube 122 . Protective tube 122 is used to supply lubricating fluid (eg, tap water) to bearing members 120A and 120B from the outside of pump casing 108 . The protective tube 122 is a substantially cylindrical member to which the bearing members 120A, 120B are fixed. The protective tube 122 is fixed by the shaft seal portion 109 of the discharge elbow 107 and extends below the bearing member 120A inside the discharge bowl 105 .

The bearing members 120A and 120B are sliding bearings provided along the rotating shaft 101 and spaced apart from each other. A shaft sleeve (not shown in FIG. 1) may be attached to the rotating shaft 101 so as to be in sliding contact with the bearing surfaces of the bearing members 120A and 120B. The bearing member 120A can be positioned at the height of the discharge bowl 105 and fixed to the protection tube 122 . The bearing member 120B can be arranged at a higher position than the bearing member 120A. The bearing member 120B can be supported by a support member 110 fixed to the pump casing 108. As shown in FIG.

Suspension pipe 106 is inserted into opening hole 1101 of installation floor 1100 . Thus, the vertical shaft pump 100 can be fixed and installed on the installation floor 1100 below the discharge elbow 107 .

As shown in FIG. 1, the protective tube 122 has a liquid supply line 1102A, one end of which is connected to a lubricating liquid supply source 1104, and the other end of which is connected to the protective tube 122. As shown in FIG. Source 1104 may be a reservoir located external to pump casing 108 and receiving a lubricating fluid such as tap water. A lubricating liquid is supplied from a supply source 1104 to the protective tube 122 through the liquid supply line 1102A. The protective tube 122 also has a discharge line 1102B having one end connected to the lubricating liquid supply source 1104 and the other end connected to the protective tube 122 . Lubricating fluid is discharged from protective tube 122 through discharge line 1102B and collected in supply source 1104 . In this embodiment, the protection tube 122 is connected to the liquid supply pipe 1102A through the wall surface of the discharge elbow 107 at a portion above the uppermost bearing member 120B (the shaft seal portion of the discharge elbow 107 in the illustrated example). It is In this embodiment, the lubricating liquid in the supply source 1104 can be pumped to the protective tube 122 depending on the installation height of the supply source 1104 .

The lubricating liquid supplied from the liquid supply pipe 1102A to the protective tube 122 flows sequentially from the bearing member 120B to the bearing member 120A. Within discharge bowl 105 of pump casing 108 , protective tube 122 forms a bowl portion 129 . The inside of the protective tube 122 is filled with water due to the inflow of the lubricating liquid from the liquid supply pipe 1102A. The lubricating liquid flows out of the protection tube 122 from the full-filled protection tube 122 through the discharge pipeline 1102B.

The discharge line 1102B communicates with the space 128 above the bowl portion 129 of the protective tube 122 . The lubricating fluid that has changed its flow upward in the space 128 is collected by the supply source 1104 via the discharge line 1102B.

Next, referring to FIG. 2, it is a partial cross-sectional view showing an example of the underwater bearing structure according to this embodiment. Here, as the bearing member 120, the bearing member 120B will be described as an example, but substantially the same configuration can be applied to the bearing member 120A. As shown in FIG. 2, the bearing member 120B can include a bearing 2120 including a bearing surface that makes sliding contact with the shaft sleeve 101B of the rotating shaft 101, and a bearing case 2122 to which the bearing 2120 is attached. The bearing member 120B may also include a cushioning material 2124 disposed between the bearing 2120 and the bearing case 2122. As shown in FIG. A specific shape of the bearing member 120B is not limited to that illustrated.

The protective tube 122 has an outer wall 1122 to which the bearing member 120B is fixed. In addition, in this embodiment, the bearing case 2122 of the bearing member 120B is arranged so as to form a part of the tube wall of the protective tube 122 . Specifically, as shown in FIG. 2, the protective tube 122 is vertically divided across the bearing member 120B. For ease of understanding, in FIG. 2, the portion of the protective tube 122 that is fixed to the upper portion of the bearing member 120B is denoted by 122A, and the portion that is connected to the lower portion of the bearing member 120B is denoted by 122B. ing. However, the protective tube 122 need not be split as shown. For example, the outer peripheral surface of the bearing case 2122 may be fixed to the inner peripheral surface of the outer wall 1122 of the protective tube 122 so that the entire bearing member 120B is positioned inside the protective tube 122 .

The protective tube 122 also has an inner wall with an inner peripheral wall 1124 and a bottom wall 1126 provided inside the outer wall 1122 . In the illustrated example, the inner wall is a member having a substantially L-shaped cross-section. Specifically, the inner wall includes a substantially vertically extending inner peripheral wall 1124 and a laterally extending bottom wall 1126 connecting the inner peripheral wall 1124 and the outer wall 1122 . However, the specific shape of the inner wall is not limited to this. The inner wall may, for example, protrude inward from the outer wall 1122 in a curved shape without distinguishing between the inner peripheral wall 1124 and the bottom wall 1126 .

In this embodiment, the outer wall 1122 , the inner peripheral wall 1124 and the bottom wall 1126 form a supply liquid receiver 1128 having a first opening 1130 in the protective tube 122 . The first opening 1130 opens upward so as to be able to receive the lubricating liquid supplied to the protective tube 122 . In this way, part of the lubricating liquid supplied to the protection tube 122 can be accumulated in the liquid supply receiver 1128 . A bottom wall 1126 of the liquid supply receiving portion 1128 is arranged at a position higher than the bearing member 120B.

The inner peripheral wall 1124 shown in FIG. 2 has a second opening 1132 near the bottom wall 1126 . A second opening 1132 permits the flow of lubricating liquid out of the receptacle 1128 . A plurality of openings 1132 formed at intervals in the circumferential direction of the protective tube 122 may be provided as the second openings 1132 . The size and number of second openings 1132 is determined by the flow rate of lubricating fluid exiting the second openings 1132 (if there are multiple second openings 1132, the number of second openings 1132). The total flow rate of the lubricating fluid) is determined so as not to exceed the flow rate of the lubricating fluid entering through the first opening 1130 . The second opening 1132 may be a single opening that extends continuously around substantially the entire circumference of the protective tube 122 .

A flow restricting member 1131 may be provided in the second opening 1132 to restrict the flow of lubricating fluid exiting the fluid receptacle 1128 . As the flow rate restricting member 1131, for example, a metal or resin liquid-permeable sheet or mesh member having pores can be used.

The flow rate restricting member 1131 allows the lubricating liquid to drip, for example, in the form of droplets as shown. However, when a plurality of second openings 1132 are formed, it is also conceivable to reduce the size of each of the second openings 1132 and form them as pores (eg, slits).

During operation of the vertical shaft pump 100, the lubricating liquid in the supply source 1104 is continuously supplied to the protective tube 122 from the liquid supply line 1102A. During this time, some of the lubricating fluid enters the fluid supply receiver 1128 through the first opening 1130 . The lubricating liquid accumulates in the supply liquid receiver 1128 while flowing out at a very small flow rate from the second opening 1132 through the flow rate restricting member 1131 . During the operation of the vertical shaft pump 100, a situation may arise in which the lubricating liquid is not supplied to the protection tube 122 due to liquid leakage from the supply source 1104, the liquid supply pipe line 1102A, or the like. In this embodiment, even when the lubricant is no longer supplied to the protective tube 122, the lubricant accumulated in the supply liquid receiving portion 1128 until then flows through the second opening 1132 to the bearing surface of the bearing member 120B. dripping or dripping into Although the volume of the liquid supply receiver 1128 is limited, by providing the flow rate limiting member 1131 in the second opening 1132, a small amount of lubricating liquid can be supplied to the bearing surface for a relatively long period of time. The flow rate supplied to the bearing surface can be on the order of several milliliters per minute.

As shown in FIG. 2, the upper end 2120a of the bearing surface may be tapered. As described above, a very small amount of lubricating liquid may be dripped in the form of water droplets. Drops of the lubricating liquid exiting the second opening 1132 can be smoothly guided to the bearing surface along the slope of the upper end 2120a of the bearing surface. However, the tapered surface as described above may not necessarily be provided, and the bearing surface may be entirely flat.

The second opening 1132 is preferably formed below the center in the height direction of the liquid supply receiver 1128 , preferably in the vicinity of the bottom wall 1126 . Also, the second opening 1132 may be provided in the bottom wall 1126 according to the specific shape and dimensions of the bearing member 120B and the liquid supply receiver 1128 .

Further, in this embodiment, the blade 130 can be attached to the rotating shaft 101 at a position lower than the bearing surface of the bearing member 120B. Wind pressure can be generated by the blades 130 rotating together with the rotating shaft 101 . The wind pressure pushes back upward the lubricating liquid that has passed through the bearing surface, and lubrication can be performed by the pushed back lubricating liquid. Moreover, the bearing surface can be cooled by wind pressure.

FIG. 3 shows another example of the flow restricting member. In this example, the flow restricting member can be tubular member 140 disposed in second opening 1132 . One end of the tubular member 140 is open within the liquid supply receiver 1128 . Further, tubular member 140 is bent downward so that the other end opens near the bearing surface (tapered surface 2120a in the illustrated example). As a result, a minute flow rate of the lubricating liquid can be supplied from a position close to the bearing surface.

FIG. 4 shows another example of the flow restricting member. In this example, second opening 1132 is formed in bottom wall 1126 . A tubular member 150 positioned in the second opening 1132 constitutes a flow restricting member. Tubular member 150 passes through the interior of bearing member 120B and opens at bearing surface 2120b. In the example of FIG. 4 , the tubular member 150 has a first conduit 152 extending from the second opening 1132 to the interior of the bearing case 2122 and a plurality of second conduits 154 connected to the first conduits 152 . include. The second conduit 154 opens at the bearing surface 2120b at different positions in the vertical direction. As a result, a very small amount of lubricating liquid can be directly supplied to the bearing surface 2120b.

FIG. 5 shows a transverse cross section of bearing 2120 of bearing member 120B shown in FIG. It can be seen in FIG. 5 that the second conduits 154 are arranged in the circumferential direction of the bearing 2120 . By supplying the lubricating liquid from multiple positions in the circumferential direction, the bearing surface 2120b can be efficiently cooled and the life of the bearing 2120 can be extended. Further, as shown in FIG. 5, it is desirable that the second pipe line 154 be arranged so as to open at an axial groove (so-called oil groove) 2120C of the bearing surface 2120b.

FIG. 6 shows an example of a pump system including a vertical shaft pump 100 according to one embodiment of the invention. The pump system comprises a source 1104 and a reservoir 1108 located outside the pump casing 108 . The pump system also includes an inlet line 1110 branching from the feed line 1102A and connected to the reservoir 1108 . That is, the inlet conduit 1110 has an inlet end connected to the liquid supply conduit 1102A in the middle of the liquid supply conduit 1102A, and an outlet end connected to the reservoir 1108 . The pump system also includes an outlet line 1112 having an inlet end connected to reservoir 1108 and an outlet end connected to protective tube 122 . The connection position between the liquid storage tank 1108 and the outlet pipe 1112 should be higher than the connection position between the outlet pipe 1112 and the protective tube 122 so that the lubricating liquid in the liquid reservoir 1108 flows down naturally. preferable.

In addition, in FIG. 6, 1114 is an air vent valve provided on the upper wall of the liquid storage tank 1108 . The air vent valve may be an air vent valve of known construction with a float located inside the valve body. When air accumulates in the valve box, the float descends along with the water surface, thereby opening the valve seat and discharging the air. As a result, the air accumulated in the liquid storage tank 1108 can be released.

Outlet line 1112 includes intermediate line 1120 in which flow restrictor 1116 is disposed. FIG. 7 is a partial view showing the configuration of the intermediate pipe 1120. As shown in FIG. An intermediate pipe 1120 is flanged to the upper and lower pipes and includes an enlarged portion 1121 having an enlarged bore. The flow rate restricting member 1116 is a member that can reduce the flow rate of the lubricating liquid from the liquid storage tank 1108, such as a low-pressure nozzle, a spray nozzle, a valve member such as a ball valve or a flap valve, or a mesh member. It is not particularly limited.

The flow restricting member 1116 can be positioned inside the enlarged portion 1121 . The interior of magnifying portion 1121 may be visualized by transparent window 1118 . The lubricating liquid that has passed through the flow restricting member 1116 may drip, for example, in the form of water droplets. Since such a minute flow rate can be visually observed through the window portion 1118, it is possible to visually confirm whether or not the lubricating liquid is appropriately supplied. In this embodiment, window 1118 is made of a transparent material. However, in other embodiments, the entire enlarged portion 1121 or the entire intermediate pipe 1120 may be made of a transparent material.

Further, in this embodiment, the outlet pipeline 1112 is provided with a switching valve 1140 (second switching valve). On the other hand, a switching valve 1142 (first switching valve) is also provided in the liquid supply line 1102A. Switching valve 1140 may be an electrically operated valve, but is preferably a manually operated valve for emergencies. Switching valve 1142 is positioned upstream of the inlet end of inlet conduit 1110 .

During operation of the vertical shaft pump 100, the switching valve 1142 of the liquid supply line 1102A is open, so the lubricating liquid of the supply source 1104 is supplied to the protection tube 122 from the liquid supply line 1102A. At the same time, the lubricating fluid is also transferred to reservoir 1108 through inlet line 1110 branching from supply line 1102A. During this time, the lubricating liquid can be stored in the liquid storage tank 1108 by keeping the switching valve 1140 closed.

In the pump system of this embodiment, when the lubricant from the supply source 1104 is no longer supplied to the protective tube 122 due to liquid leakage or the like, for example, the operator manually closes the switching valve 1142 and opens the switching valve 1140 to The lubricating liquid in reservoir 1108 can be supplied to protective tube 122 . Until the switching valve 1140 is opened, the lubricating liquid accumulated in the liquid supply receiving portion 1128 of the protective tube 122 is supplied to the bearing surface, so that the bearing surface can be prevented from being left in a dry state.

In addition, the pump system of this embodiment has an inlet end connected to the discharge elbow 107 to receive part of the liquid (in other words, liquid handled) transferred by the vertical shaft pump 100, and the downstream side of the switching valve 1142. A secondary line 1200 having an outlet end connected to the feed line 1102A. The auxiliary pipeline 1200 is provided with a switching valve 1202 (third switching valve). Switching valve 1202 may be an electrically operated valve, but is preferably a manually operated valve for emergencies.

When all the lubricating liquid in the liquid storage tank 1108 has been supplied to the protection tube 122, for example, the operator can manually close the switching valve 1142 and open the switching valve 1202. FIG. As a result, the handling liquid taken out from the discharge elbow 107 can be supplied to the protection tube 122 through the auxiliary conduit 1200 and the liquid supply conduit 1102A. In addition, the liquid to be treated taken out from the discharge elbow 107 can be stored in the liquid storage tank 1108 through the liquid supply pipe line 1102A. Since the lubricating liquid accumulated in the liquid supply receiving portion 1128 of the protective tube 122 is supplied to the bearing surface until the switching valve 1202 is opened, it is possible to prevent the bearing surface from being left in a dry state. .

However, in the pump system of FIG. 6, the feed receiver 1128 may be omitted.

A foreign matter removing device 1204 such as a strainer can be arranged in the auxiliary pipeline 1200 . As a result, the liquid to be handled can be supplied to the protection tube 122 in a state in which foreign matter is removed.

As described above, the embodiment of the present invention is useful when a failure such as liquid leakage occurs in the supply system of the lubricating liquid during operation of the vertical shaft pump with a protective tube. Even when the lubricating liquid is no longer supplied from the supply source 1104 , the lubricating liquid can be supplied from the liquid supply receiver 1128 provided in the protection tube 122 or from the liquid storage tank 1108 separate from the supply source 1104 . In addition, since the flow rate of the lubricating liquid can be reduced by the flow rate restricting members 140, 150, 1116, 1131, the lubricating liquid can be continuously supplied to the bearings for a relatively long period of time. The flow rate of the lubricating liquid may be as small as several ml per minute. It is possible to operate the vertical shaft pump while sufficiently reducing the heat generation of the bearings even with a very small flow rate of the lubricating fluid.

Although the embodiment of the present invention has been described above, the above-described embodiment of the present invention is for facilitating understanding of the present invention, and does not limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within the range that at least part of the above problems can be solved or at least part of the effect is achieved. is.

The present invention includes the following aspects.
1. A submersible bearing structure that supports a rotating shaft to which an impeller of a vertical shaft pump is attached,
an underwater bearing member that rotatably supports the rotating shaft;
a protection tube having an outer wall to which the underwater bearing member is fixed;
The protective tube has an inner wall provided inside the outer wall, and the outer wall and the inner wall define a liquid supply receiver having a first opening capable of receiving the lubricating liquid for the underwater bearing member from above. ,
The liquid supply receiver is arranged above the underwater bearing member,
A water bearing structure, wherein the inner wall has a second opening for permitting the flow of lubricating fluid out of the receptacle.
2. 1. above, wherein the inner wall has a plurality of second openings spaced apart in a circumferential direction with respect to the protective tube. underwater bearing structure described in .
3. 1. above, wherein the second opening is provided with a flow rate limiting member for limiting the flow rate of the lubricating liquid coming out of the liquid supply receiver; or 2. underwater bearing structure described in .
4. 3. above, wherein the flow restricting member includes a liquid-permeable sheet or mesh-like member covering the second opening. underwater bearing structure described in .
5. 3. above, wherein the flow restricting member includes a tubular member disposed in the second opening. or 4. underwater bearing structure described in .
6. 1. above, wherein the upper end of the bearing surface of the underwater bearing member is tapered; ~ 5. 3. The underwater bearing structure according to any one of 1.
7. 3. above, wherein the flow restricting member includes a tubular member that passes through the interior of the underwater bearing member and opens at the bearing surface from the second opening. ~ 5. 3. The underwater bearing structure according to any one of 1.
8. 1. above, having a blade fixed to the rotating shaft at a position lower than the underwater bearing member. ~7. 3. The underwater bearing structure according to any one of 1.
9. 1. The inner wall comprises an inner peripheral wall and a bottom wall and has a substantially L-shaped cross section, and the second opening is provided at or near the bottom wall. ~8. 3. The underwater bearing structure according to any one of 1. 10. 1 above. ~ 9. A vertical shaft pump comprising the submersible bearing structure according to any one of the above.
11. 10 above. and the vertical shaft pump described in
a source of lubricating fluid;
a feed line having an inlet end connected to a supply source and an outlet end connected to a protective tube;
a reservoir separate from the supply for storing lubricating fluid;
an inlet conduit having an inlet end connected to the feed conduit and an outlet end connected to the reservoir;
an outlet line having an inlet end connected to the liquid storage tank and an outlet end connected to the protective tube; the liquid supply line is provided with a first switching valve; 2 switching valves are provided,
Further, the auxiliary has an inlet end connected to the pump casing of the vertical shaft pump and capable of receiving liquid transferred by the vertical shaft pump, and an outlet end connected to the feed line downstream of the first switching valve. A pipeline is provided, and a third switching valve is provided in the auxiliary pipeline,
pump system.
12. 11. above, wherein the liquid storage tank is installed at a position higher than the outlet end of the outlet conduit. The pump system described in .
13. 12. above, wherein the outlet line is provided with a flow restricting member, thereby limiting the flow rate of the lubricating liquid through the outlet line; The pump system described in .
14. 13. The above-mentioned 13. above, wherein a transparent window is provided in the outlet pipe, and the lubricating liquid that has passed through the flow restricting member is visible through the window. The pump system described in .
15. 11 above. ~ 14. A method for supplying lubricating liquid in the pump system according to any one of
A first step of opening the first switching valve and closing the second switching valve to transfer the lubricating liquid from the supply source to the protection pipe and the liquid storage tank;
a second step of closing the first switching valve and opening the second switching valve to supply the lubricating liquid in the reservoir to the protection pipe;
and, after the second step, a third step of opening a third switching valve to supply liquid to the liquid supply line.

INDUSTRIAL APPLICABILITY The present invention can be widely applied to vertical shaft pumps with protective tubes.

100 Vertical shaft pump 101 Rotary shafts 101A, 101B Shaft sleeve 102 Impeller 103 Guide vane 104 Suction bell 105 Discharge bowl 106 Suspension pipe 107 Discharge elbow 108 Pump casing 109 Shaft seal 110 Support members 120A, 120B Underwater bearing member 122, 122A, 122B Protective tube 128 Space 129 Bowl portion 130 Blade 140 Tubular member 150 Tubular member 152 First conduit 154 Second conduit 1100 Installation floor 1101 Opening hole 1102A Liquid supply conduit 1102B Discharge conduit 1104 Supply source 1108 Reservoir Liquid tank 1110 Inlet pipe 1112 Outlet pipe 1114 Air vent valve 1116 Flow rate limiting member 1118 Window 1120 Intermediate pipe 1121 Enlarged parts 1140, 1142 Switching valve 1122 Outer wall 1124 Inner peripheral wall (inner wall)
1126 bottom wall (inner wall)
1128 Supply liquid receiving portion 1130 First opening 1131 Flow rate limiting member 1132 Second opening 1200 Auxiliary pipeline 1202 Switching valve 1204 Foreign matter removing device 2120 Bearing 2120a Upper end 2120b Bearing surface (sliding surface)
2120c Axial groove 2122 Bearing case 2124 Cushioning material

Claims (15)

A submersible bearing structure that supports a rotating shaft to which an impeller of a vertical shaft pump is attached,
an underwater bearing member that rotatably supports the rotating shaft;
a protective tube having an outer wall to which the underwater bearing member is fixed;
The protective tube has an inner wall provided inside the outer wall, and a liquid supply receiver having a first opening capable of receiving the lubricating liquid for the underwater bearing member from above by the outer wall and the inner wall. is defined and
The liquid supply receiver is arranged above the underwater bearing member,
The underwater bearing structure, wherein the inner wall has a second opening for allowing flow of lubricating liquid out of the feed receptacle. 2. The underwater bearing structure according to claim 1, wherein said inner wall has a plurality of said second openings spaced circumferentially with respect to said protective tube. 3. The underwater bearing structure according to claim 1, wherein a flow rate restricting member for restricting the flow rate of the lubricating liquid coming out of the liquid supply receiver is arranged in the second opening. 4. The underwater bearing structure according to claim 3, wherein said flow restricting member includes a liquid-permeable sheet or mesh-like member covering said second opening. 5. The underwater bearing structure according to claim 3, wherein said flow restricting member comprises a tubular member arranged in said second opening. The underwater bearing structure according to any one of claims 1 to 5, wherein the upper end of the bearing surface of said underwater bearing member is tapered. 6. The underwater bearing structure according to any one of claims 3 to 5, wherein said flow restricting member includes a tubular member opening from said second opening through the inside of said underwater bearing member and opening at a bearing surface. The underwater bearing structure according to any one of claims 1 to 7, further comprising a blade fixed to said rotating shaft at a position lower than said underwater bearing member. Claims 1 to 8, wherein the inner wall comprises an inner peripheral wall and a bottom wall and has a substantially L-shaped cross section, and the second opening is provided at or near the bottom wall. 3. The underwater bearing structure according to any one of 1. A vertical shaft pump comprising the submersible bearing structure according to any one of claims 1 to 9. a vertical axis pump according to claim 10;
a source of lubricating fluid;
a liquid supply conduit having an inlet end connected to the supply source and an outlet end connected to the protection tube;
a reservoir separate from the supply for storing lubricating fluid;
an inlet conduit having an inlet end connected to the feed conduit and an outlet end connected to the reservoir;
an outlet conduit having an inlet end connected to the reservoir and an outlet end connected to the protective tube;
A first switching valve is provided in the liquid supply line, and a second switching valve is provided in the outlet line,
Further, an inlet end connected to the pump casing of the vertical shaft pump and capable of receiving the liquid transferred by the vertical shaft pump, and an outlet end connected to the liquid supply pipe on the downstream side of the first switching valve. A third switching valve is provided in the auxiliary pipeline,
pump system. 12. The pump system of claim 11, wherein the reservoir is located higher than the outlet end of the outlet line. 13. The pump system of claim 12, wherein the outlet line is provided with a flow restrictor to restrict the flow of lubricating liquid through the outlet line. 14. The pump system of claim 13, wherein the outlet line is provided with a transparent window through which lubricating fluid that has passed through the flow restrictor is visible. A method for supplying lubricating liquid in the pump system according to any one of claims 11 to 14,
a first step of opening the first switching valve and closing the second switching valve to transfer the lubricating liquid from the supply source to the protection pipe and the liquid storage tank;
a second step of closing the first switching valve and opening the second switching valve to supply the lubricating liquid in the liquid storage tank to the protection pipe;
and a third step of opening the third switching valve after the second step and supplying the liquid to the liquid supply pipeline.

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