JP2021131057A - Water supply system - Google Patents

Abstract

To provide a water supply system including a canned motor pump with a simple cooling structure.SOLUTION: A water supply system 1 includes: multiple canned motor pumps 2; and a connection pipe 50 for connecting the multiple canned motor pumps 2. A motor casing 35 includes circulation holes 26, 46 which are formed in both sides thereof and through which liquid passes. Multiple motor casings 35 are communicated through the connection pipe 50.SELECTED DRAWING: Figure 4

Description

The present invention relates to a water supply device.

The canned motor pump has a characteristic structure described below.
(1) Since the canned motor pump has a structure that does not require a shaft sealing device such as a mechanical seal, it is possible to reduce failures caused by liquid leakage.
(2) Since the CAN DO motor pump has a structure for cooling the motor with a liquid circulating inside the pump, it is not necessary to provide a fan for cooling the motor. Therefore, the CAN DO motor pump can realize low noise.
(3) Since the canned motor pump can use a plain bearing having a longer life than the ball bearing, the overall life of the canned motor pump can be extended. Further, the canned motor pump having a slide bearing can be operated at a high rotation speed while maintaining quietness.

Japanese Unexamined Patent Publication No. 9-209976 Japanese Unexamined Patent Publication No. 9-195975 Japanese Unexamined Patent Publication No. 2007-327441

Since the can motor pump has the above-mentioned characteristics, it is desirable to use the can motor pump as the water supply device. However, the cooling structure of a general canned motor pump is complicated, and the manufacturing cost of the canned motor pump is high.

Therefore, an object of the present invention is to provide a water supply device including a can motor pump having a simple cooling structure.

In one aspect, a water supply device is provided that includes a plurality of canned motor pumps and a connecting pipe that connects the plurality of canned motor pumps. Each of the plurality of canned motor pumps includes a motor casing, and the motor casing has flow holes formed at both ends thereof for allowing liquid to pass through, and accommodates the motor. The motor casing of the above is communicated with the connecting pipe.

In one aspect, the motor casing comprises an end cover that constitutes one end of the motor casing, and each of the plurality of canned motor pumps has a connecting pipe in the flow hole formed in the end cover. It is equipped with a communication cover to be connected.
In one aspect, the motor casing comprises a motor frame that is arranged around the motor and is connected to the end cover, the communication cover covering the end cover and the motor frame. The connecting pipe is connected to the communicating cover at a position opposite to the end cover.
In one aspect, the motor casing comprises a non-conductive can located between the motor rotor of the motor and the motor stator of the motor.

In one aspect, the motor casing comprises a reinforcing tube that reinforces the can.
In one aspect, the water supply device comprises a suction pipe and a discharge pipe connected to the plurality of canned motor pumps, and a bypass pipe connected to the suction pipe and the discharge pipe. , Connected to the bypass pipe.
In one aspect, the water supply device comprises an inverter arranged adjacent to the plurality of can motor pumps.

According to the present invention, a water supply device having characteristics as a canned motor pump (that is, (1) prevention of liquid leakage, (2) realization of low noise, (3) operation at high rotation speed) has a simple cooling structure. As a result, the cost related to the manufacture of the water supply device can be reduced.

It is a figure which shows one Embodiment of a water supply device. It is sectional drawing of the pump device. It is a figure which shows the flow of the liquid in a pump device at the time of operation of a pump device. It is a figure which shows the connecting pipe which connects a plurality of pump devices. It is a figure which shows the other embodiment of a water supply device. It is a figure which shows still another embodiment of a water supply device. It is a figure which shows the other embodiment of the communication cover. It is a figure which shows still another embodiment of a communication cover. It is a figure which shows the other embodiment of the connecting pipe. It is a figure which shows the water supply device which includes three pump devices.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a water supply device. In the embodiment shown in FIG. 1, the water supply device 1 is a water supply device used for supplying water to a building such as an office building or an apartment building. The water supply device 1 is connected to a supply source such as a water main. The water supply device 1 is connected to a water supply device (for example, a faucet) arranged inside the building, and boosts the transport liquid (for example, water) from the supply source to supply the water supply device of the building.

As shown in FIG. 1, the water supply device 1 includes a plurality of pump devices (two in the embodiment shown in FIG. 1) 2A and 2B, and suction pipes (that is, suction headers) connected to the respective pump devices 2A and 2B. ) 3 and the discharge pipe (that is, the discharge collecting pipe) 4, the bypass pipe 5 connected to the suction pipe 3 and the discharge pipe 4, the inverter 6 which is an example of the variable speed operation of each pump device 2, and each of them. It includes a control unit 7 that controls the operation of the pump devices 2A and 2B. Although not shown, the water supply device 1 includes a pressure tank that holds the discharge pressures of the pump devices 2A and 2B for a certain period of time, a discharge side pressure sensor attached to the discharge pipe 4, and a suction side pressure sensor attached to the suction pipe 3. And have. The components of the water supply device 1 may be housed in a cabinet (not shown). Hereinafter, in the present specification, the pump devices 2A and 2B may be simply referred to as the pump device 2 without distinction.

In the present embodiment, the pump device 2 is an vertical shaft pump device arranged in an upright posture (see the vertical and horizontal directions in FIGS. 1 and 2), but in one embodiment, the pump device 2 is arranged in a horizontal posture. It may be a horizontal axis pump device.

As shown in FIG. 1, the suction pipe 3 includes suction branch portions 3A and 3B connected to a suction port 8 of each pump device 2. An on-off valve 10 is attached to the suction branch portion 3A, and an on-off valve 11 is attached to the suction branch portion 3B. The discharge pipe 4 includes discharge branch portions 4A and 4B connected to the discharge port 9 of each pump device 2. An on-off valve 12 and a check valve 14 are attached to the discharge branch portion 4A, and an on-off valve 13 and a check valve 15 are attached to the discharge branch portion 4B.

In the embodiment shown in FIG. 1, the water supply device 1 is a direct water supply device. In one embodiment, the pump device 2 may be applied to a water supply device that does not include a bypass pipe 5. The bypass pipe 5 is provided so that water can be supplied only by the pressure of the liquid flowing into the water supply device 1 without operating the pump device 2. The bypass pipe 5 is arranged so as to bypass the pump device 2. More specifically, the upstream end of the bypass pipe 5 is connected to the suction pipe 3, and the downstream end of the bypass pipe 5 is connected to the discharge pipe 4. A check valve 16 is attached to the bypass pipe 5.

In the embodiment shown in FIG. 1, the pump device 2 is a can motor pump. The canned motor pump has a structure in which a liquid passes through the inside thereof. Since the two pump devices 2 have the same structure, the structure of one of the pump devices 2 will be described below with reference to the drawings.

FIG. 2 is a cross-sectional view of the pump device 2. As shown in FIG. 2, the pump device 2 includes a pump P and a motor unit M for driving the pump P. The pump P includes an impeller 20 for transferring a liquid, a rotating shaft (main shaft) 22 to which the impeller 20 is fixed, and a pump casing 24 for accommodating the impeller 20.

In the embodiment shown in FIG. 2, the pump P is a multi-stage pump including a plurality of (that is, four) impellers 20. In one embodiment, the pump P may be a single-stage pump with a single impeller 20.

A casing cover 25 is fixed to the opening on the high pressure side of the pump casing 24. The rotating shaft 22 extends through the casing cover 25. The casing cover 25 is formed with a flow hole (in other words, an inflow hole) 26 for passing a part of the liquid sucked into the pump casing 24 with the motor unit M. A part of the liquid boosted by the rotation of the impeller 20 is guided to the motor unit M through these plurality of inflow holes 26. Although two inflow holes 26 are drawn in FIG. 2, the number of inflow holes 26 is not limited to this embodiment.

The pump device 2 includes a motor 30 for rotating the rotating shaft 22, slide bearings 31 and 32 for rotatably supporting the rotating shaft 22, and a motor casing 35 for accommodating the motor 30. The casing cover 25 is a part of the components of the motor casing 35.

The motor 30 includes a motor rotor 36 fixed to the rotating shaft 22 and a motor stator 37 arranged around the motor rotor 36. The motor stator 37 includes a stator core 37a and a plurality of coils 37b wound around the stator core 37a. The plurality of coils 37b are arranged so as to surround the motor rotor 36.

The rotary shaft 22 is rotatably supported by slide bearings 31 and 32 arranged on both sides of the motor 30. In the embodiment shown in FIG. 1, the slide bearing 31 is arranged below the motor 30, and the slide bearing 32 is arranged above the motor 30. The plain bearing 31 is a bearing that supports the radial load and the axial load of the rotating shaft 22. The plain bearing 32 receives a radial load, but does not positively receive an axial load. When the pump device 2 is started, the slide bearing 32 may be pressed against the end cover 38 (described later). A thrust plate 33 is arranged between the slide bearing 31 and the motor rotor 36, and a thrust plate 34 is arranged between the slide bearing 32 and the motor rotor 36.

The motor casing 35 includes a casing cover 25 that supports the slide bearing 31, an end cover 38 that supports the slide bearing 32, and a motor frame 39 that is arranged between the casing cover 25 and the end cover 38. ..

The motor frame 39 is connected to both the casing cover 25 and the end cover 38. The casing cover 25 closes one open end of the motor frame 39, and the end cover 38 closes the other open end of the motor frame 39. The end cover 38 is arranged on the opposite side of the motor 30 (upper in the present embodiment), and the casing cover 25 is arranged on the pump side (lower in the present embodiment) of the motor 30. A motor stator 37 is fixed to the inner peripheral surface of the motor frame 39.

As shown in FIG. 2, a cylindrical can (stator can) 40 is arranged between the motor rotor 36 and the motor stator 37 so as to surround the motor rotor 36. The motor stator 37 is arranged between the motor frame 39 and the can 40, and is fixed to the outer peripheral surface of the can 40. The motor rotor 36, the motor stator 37, and the can 40 are arranged concentrically. The motor stator 37 is arranged in the stator chamber SC formed by the motor frame 39, the casing cover 25, the end cover 38, and the can 40.

A cylindrical can (rotor can) 41 is arranged on the motor rotor 36. The can 41 covers the motor rotor 36 and is arranged so as to face the can 40.

When a current is passed through the coil 37b of the motor stator 37, a magnetic field is formed in the motor stator 37, and the magnetic field causes the motor rotor 36 to rotate. In the embodiment shown in FIG. 2, the cans 40 and 41 are composed of non-conductive members (for example, resin) having no conductivity. In a can motor pump including a can made of a conductive member, an eddy current flows inside the can due to the drive of the motor, and a loss (can loss) occurs. This loss adversely affects motor efficiency. In the embodiment shown in FIG. 2, since the cans 40 and 41 are composed of non-conductive members, no eddy current is generated. Therefore, the pump device 2 can reduce the above loss as compared with the case where the can is composed of the conductive member.

The motor rotor 36 rotates the impeller 20 through the rotating shaft 22. When the impeller 20 rotates together with the rotating shaft 2, the liquid is sucked into the pump casing 24 from the suction port 8, boosted by the rotation of the impeller 20, and then discharged from the discharge port 9.

FIG. 3 is a diagram showing a flow of liquid in the pump device 2 during operation of the pump device 2. As shown by the arrow in FIG. 3, a part of the liquid sucked into the pump casing 24 is guided to the motor portion M through the inflow hole 26 formed in the casing cover 25. A portion of the liquid passes through a small gap between the plain bearing 31 and the rotating shaft 22 to cool and lubricate the plain bearing 31.

The liquid that has passed through the inflow hole 26 flows through the space C1 surrounded by the can 40 (see the arrow in FIG. 3). When the liquid flows through the space C1 surrounded by the can 40, the pressure of the liquid acts on the can 40. When the can 40 is made of a non-conductive member (for example, resin) having low strength, the can 40 may be deformed outward in the radial direction due to the pressure of the liquid. Therefore, in the embodiment shown in FIG. 3, the motor casing 35 includes a reinforcing pipe 42 that reinforces the can 40.

As shown in FIG. 3, the reinforcing pipe 42 is made of a metal member having high strength and is fixed to the outer peripheral surface of the can 40. More specifically, the reinforcing pipe 42 is composed of two divided frames 42A and 42B having a cylindrical shape. The dividing frames 42A and 42B are arranged on both sides of the stator core 37a. The split frame 42A is arranged adjacent to the end cover 38, and the split frame 42B is arranged adjacent to the casing cover 25. The reinforcing pipe 42 arranged on the outside of the can 40 prevents the can 40 from being deformed.

As shown in FIG. 3, the end cover 38 has a flow hole (in other words, an outflow hole) 46 for passing the liquid flowing inside the can 40 to the outside of the motor casing 35. Although two outflow holes 46 are drawn in FIG. 3, the number of outflow holes 46 is not limited to this embodiment. The liquid flowing inside the can 40 flows out of the motor casing 35 through the outflow hole 46. In this way, the motor casing 35 having the inflow hole 26 and the outflow hole 46 allows the passage of liquid. A portion of the liquid flows through a small gap between the plain bearing 32 and the rotating shaft 22 to cool and lubricate the plain bearing 32.

FIG. 4 is a diagram showing a connecting pipe 50 that connects a plurality of pump devices 2. In FIG. 4, the water supply device 1 includes two pump devices 2A and 2B. As shown in FIG. 4, the water supply device 1 includes a connecting pipe 50 that connects a plurality of pump devices 2A and 2B. The plurality of motor casings 35 are communicated with each other by a connecting pipe 50. In other words, the connecting pipe 50 has a structure in which the liquid introduced into the motor casing 35 of the pump device 2 during operation is supplied to the motor casing 35 of the pump device 2 which is stopped.

As shown in FIGS. 3 and 4, the pump device 2 includes a communication cover 51 that communicates (connects) the connecting pipe 50 with the outflow hole 46 of the motor casing 35. In the embodiment shown in FIGS. 3 and 4, the communication cover 51 has a cup shape that covers the entire motor casing 35, and the opening end 51a of the communication cover 51 is connected to the casing cover 25. A sealing member 53 such as an O-ring is arranged between the communication cover 51 and the casing cover 25. The seal member 53 prevents leakage of the liquid flowing through the gap between the communication cover 51 and the motor casing 35.

The communication cover 51 has a connection hole 51b to which the connection pipe 50 can be connected, and the connection pipe 50 is connected to the connection hole 51b. In the embodiment shown in FIGS. 3 and 4, the connection hole 51b is arranged at a position opposite to the end cover 38. In other words, the connection hole 51b is formed in the lower part of the communication cover 51.

Since the can 41 made of resin has a low thermal conductivity, the rotor 36 is not efficiently cooled through the can 41 even if the liquid comes into contact with the can 41. However, since the rotor 36 is fixed to the rotating shaft 22 made of a material having high thermal conductivity (for example, metal), the heat generated from the rotor 36 is released through the rotating shaft 22. On the other hand, when the can 40 is made of resin, the motor stator 37 is not efficiently cooled through the can 40 even if the liquid comes into contact with the can 40.

Therefore, in the present embodiment, the motor frame 39 is composed of a metal member having a high thermal conductivity (for example, a metal member having a higher thermal conductivity than a resin which is an example of a non-conductive member). The liquid flowing out from the outflow hole 46 of the end cover 38 flows through the space C2 between the motor casing 35 and the communication cover 51, and comes into contact with the motor frame 39 having high thermal conductivity. Since the motor stator 37 is fixed to the inner peripheral surface of the motor frame 39, the motor stator 37 is cooled via the motor frame 39.

The liquid that has flowed through the space C2 between the motor casing 35 and the communication cover 51 flows into the connecting pipe 50 through the connection hole 51b of the communication cover 51. In the embodiment shown in FIG. 4, the two pump devices 2 are configured to perform independent alternating operation. Therefore, when one pump device 2 is in operation, the other pump device 2 is stopped. Since the connecting pipe 50 connects the two pump devices 2, the boosted liquid in the operating pump device 2 passes through the connecting pipe 50 and flows into the stopped pump device 2.

As shown in FIG. 4, the two pump devices 2 have the same structure. The liquid flowing into the stopped pump device 2 rises in the space C2 between the communication cover 51 and the motor casing 35, and is surrounded by the can 40 through the flow hole (that is, the outflow hole) 46 of the end cover 38. It descends in space C1. Further, the liquid flows to the pump P through the flow hole (that is, the inflow hole) 26 formed in the casing cover 25, passes through the plurality of impellers 20 and the suction port 8, and is returned to the suction pipe 3.

In this way, when one of the pump devices 2 is operated, the liquid flowing through the suction pipe 3 flows into the pump device 2 during operation, passes through the motor unit M, and cools the motor 30. The liquid that has cooled the motor 30 flows into the stopped pump device 2, flows through the motor unit M and the pump P in this order, and is returned to the suction pipe 3.

As described above, the water supply device 1 can cool the pump device 2 with a simple structure including a connecting pipe 50 for connecting the plurality of pump devices 2. In a general canned motor pump, a through hole is formed at the center of the rotating shaft, and the motor is cooled through the through hole (see, for example, Patent Document 1). However, it is not easy to form such a through hole on the rotation axis. In particular, in a can motor pump that employs a multi-stage pump, the length of the rotating shaft becomes long, and as a result, it is not even easier to form a through hole.

When the CAN DO motor pump is configured to circulate the liquid through a through hole formed in the rotating shaft, the liquid flows between the inside of the rotating shaft and the gap between the stator and the rotor. Therefore, when the stator can is made of a material having low thermal conductivity such as resin, the stator cannot be effectively cooled.

According to the present embodiment, since the water supply device 1 includes a connecting pipe 50 that connects the two pump devices 2, the pump device 2 needs to have a through hole that allows the passage of liquid in the rotating shaft 22. There is no. Further, even if the can 40 is made of a material having a low thermal conductivity such as a resin, the stator 37 is effectively cooled through the motor frame 39. Therefore, the water supply device 1 having the characteristics as a can motor pump (that is, (1) prevention of liquid leakage, (2) realization of low noise, (3) operation at high rotation speed) has a simple cooling structure. Can be carried out. In the pump device 2 having such a structure, since it is not necessary to form a through hole in the rotating shaft 22, a multi-stage pump having a larger number of stages can be adopted. Further, the cost related to the manufacture of the water supply device 1 (more specifically, the pump device 2) can be reduced.

The liquid discharged from the pump device 2 during operation is heated by the heat of the motor 30, and the heated liquid (heated liquid) flows into the stopped pump device 2. The heated liquid flowing into the stopped pump device 2 can prevent the temperature of the stopped pump device 2 from dropping. When the pump device 2 is operated, the temperature of the component of the pump device 2 rises, and when the operation of the pump device 2 is stopped, the temperature of the component of the pump device 2 decreases. Due to the repeated temperature rise and fall, the components of the pump device 2 may be affected by temperature fatigue and may be damaged. According to the present embodiment, the water supply device 1 can prevent damage to the components of the pump device 2 due to temperature fatigue, and can realize a long life.

FIG. 5 is a diagram showing another embodiment of the water supply device 1. As shown in FIG. 5, for the purpose of cooling the inverter 6, the inverter 6 may be arranged so as to be adjacent to the pump devices 2A and 2B (particularly, the communication covers 51 and 51). In the embodiment shown in FIG. 5, the inverter 6 is arranged on the pump devices 2A and 2B. The inverter 6 includes an inverter element 6a and an inverter case 6b for accommodating the inverter element 6a. In the embodiment shown in FIG. 5, the inverter case 6b is mounted on the communication covers 51 and 51. With such an arrangement, the water supply device 1 can more reliably eliminate the influence of temperature fatigue on the inverter 6.

The inverter element 6a is a member that is particularly susceptible to temperature fatigue. The temperature of the inverter element 6a becomes high while the inverter 6 is being driven, while the temperature of the inverter element 6a becomes low while the inverter 6 is stopped. In particular, in cold regions, the temperature difference of the inverter element 6a between the driving of the inverter 6 and the driving stop is large. As described above, repeated temperature rise and fall of the inverter element 6a causes damage to the inverter element 6a.

According to the embodiment shown in FIG. 5, the heating liquid flowing between the operating pump device 2 and the stopped pump device 2 heats the inverters 6 arranged on the plurality of pump devices 2, and the inverter element. The temperature difference of 6a can be reduced. As a result, the water supply device 1 can realize a long life of the inverter 6.

FIG. 6 is a diagram showing still another embodiment of the water supply device 1. In the embodiment shown in FIG. 5, the inverter 6 is arranged above (contacting or separating) the pump devices 2A and 2B, but as shown in FIG. 6, the inverter 6 is located lateral to the pump devices 2A and 2B. It may be arranged (contact or separation). Even in this case, the inverter 6 is arranged so as to be adjacent to the pump devices 2A and 2B (particularly, the communication covers 51 and 51).

In the embodiments shown in FIGS. 5 and 6, the inverter 6 is located above the pump devices 2A and 2B, assuming that the pump devices 2A and 2B are vertical pump devices (see the vertical and horizontal directions in FIGS. 5 and 6). Or it is placed on the side. In one embodiment, the inverter 6 may be arranged above or to the side of the pump devices 2A, 2B even when the pump devices 2A, 2B are horizontal axis pump devices.

In one embodiment, the pump device 2 may include a motor assembly having an integrated structure with a built-in inverter 6. The motor assembly is a mechanical device including a combination of a motor unit M and an inverter 6. In the pump device 2 including the motor assembly and the pump P, the pump P, the motor unit M, and the inverter 6 are arranged in series in the axis CL direction of the rotating shaft 22. Even with such a configuration, the water supply device 1 can cool the inverter 6 by the liquid flowing through the motor unit M and prevent the inverter 6 from failing due to temperature fatigue.

As described above, the two pump devices 2 are configured to perform independent alternating operation. Therefore, as shown in FIG. 4, when the pump device 2A is in operation, the pump device 2B is in operation. In this case, the liquid flowing through the suction pipe 3 flows from the pump device 2A toward the pump device 2B (first flow direction). On the contrary, when the pump device 2A is stopped, the pump device 2B is in operation. In this case, the liquid flowing through the suction pipe 3 flows from the pump device 2B toward the pump device 2A (second flow direction). The first flow direction and the second flow direction are opposite directions.

For example, when foreign matter is mixed in the liquid flowing through the suction pipe 3, the foreign matter may be caught in the flow path of the liquid in the pump device 2. According to the present embodiment, when the operation of the pump device 2 is switched, the flow direction of the liquid is switched between the first flow direction and the second flow direction, and the liquid flows backward. Therefore, the foreign matter caught in the flow path is removed by the backflowing liquid. In this way, the water supply device 1 can remove the foreign matter mixed in the pump devices 2A and 2B by switching the operation between the pump devices 2A and 2B.

FIG. 7 is a diagram showing another embodiment of the communication cover 51. In FIG. 7, instead of the can 40 which is a non-conductive member, a can 60 made of a member having high thermal conductivity (for example, metal or the like) is provided. In this case, the motor 30 (more specifically, the motor stator 37) is cooled by the liquid flowing inside the can 60. Therefore, it is not necessary to bring the liquid flowing out from the outflow hole 46 of the end cover 38 into contact with the motor frame 39. As a result, as shown in FIG. 7, the connection hole 51b may be arranged above the communication cover 51. In the embodiment shown in FIG. 7, the can 60 is made of a metal having a high thermal conductivity. Therefore, the pump device 2 does not include the reinforcing pipe 42.

FIG. 8 is a diagram showing still another embodiment of the communication cover 51. In the embodiment shown in FIG. 8, the communication cover 51 has a cup shape that covers the outflow hole 46 of the end cover 38. The open end 51a of the communication cover 51 is connected to the end cover 38. Similar to the embodiment shown in FIG. 7, when the can 40 is composed of a member having high thermal conductivity, the motor 30 is cooled by the liquid flowing inside the can 40. Therefore, in the embodiment shown in FIG. 8, the communication cover 51 has a structure for introducing the liquid flowing out from the outflow hole 46 of the end cover 38 into the connecting pipe 50.

In one embodiment, the connecting pipe 50 may be directly connected to the outflow hole 46. When a plurality of outflow holes 46 are provided, the connecting pipe 50 has a number of branch portions corresponding to the number of outflow holes 46.

FIG. 9 is a diagram showing another embodiment of the connecting pipe 50. In the embodiment shown in FIG. 9, the connecting pipe 50 is connected not only to the pump devices 2A and 2B but also to the bypass pipe 5. As described above, the pump devices 2A and 2B are configured to perform independent alternating operation. In order to smoothly switch the operations of the pump devices 2A and 2B, the operation of the other pump device 2 may be started immediately before the operation of the one pump device 2 is completed.

In this case, both the pump devices 2A and 2B are operated at the same time for a certain period of time, but the liquid boosted by the operation of the pump devices 2A and 2B flows into the bypass pipe 5 through the connecting pipe 50. Therefore, even if the operation of the other pump device 2 is started immediately before the operation of the one pump device 2 is completed, the flow of the liquid flowing through the connecting pipe 50 is not obstructed.

FIG. 10 is a diagram showing a water supply device including three pump devices 2. In FIG. 10, only the motor casing 35 and the connecting pipe 50 of the pump devices 2A, 2B, and 2C are drawn for easy viewing.

In the above-described embodiment, the water supply device 1 including the two pump devices 2A and 2B has been described, but as shown in FIG. 10, the water supply device 1 may include the three pump devices 2A, 2B and 2C. good. In one embodiment, the water supply device 1 may include four or more pump devices 2.

As shown in FIG. 10, the connecting pipe 50 is connected to three pump devices 2A, 2B, 2C, and these pump devices 2A, 2B, 2C are connected. Also in the embodiment shown in FIG. 10, one of the plurality of pump devices 2 is stopped during the alternate operation. Therefore, the connecting pipe 50 supplies the liquid introduced into the motor casing 35 of the operating pump device 2 to the motor casing 35 of the stopped pump device 2. As a result, the water supply device 1 can achieve the same effect as that of the above-described embodiment.

All three pumping devices 2A, 2B, 2C may be in operation. In this case, by connecting the connecting pipe 50 to the bypass pipe 5, the liquid boosted by the operation of the pump devices 2A, 2B, and 2C flows into the bypass pipe 5 through the connecting pipe 50.

The above-described embodiment is described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is construed in the broadest range according to the technical idea defined by the claims.

1 Water supply device 2 (2A, 2B, 2C) Pump device 3 Suction pipe 3A, 3B Suction branch 4 Discharge pipe 4A, 4B Discharge branch 5 Bypass pipe 6 Inverter 6a Inverter element 6b Inverter case 8 Suction port 9 Discharge port 10 Opening and closing Valve 11 On-off valve 12 On-off valve 13 On-off valve 14 Check valve 15 Check valve 16 Check valve 20 Impeller 22 Rotating shaft 24 Pump casing 25 Casing cover 26 Flow hole (inflow hole)
30 Motor 31, 32 Slide bearing 35 Motor casing 36 Motor rotor 37 Motor stator 37a Stator core 37b Coil 38 End cover 39 Motor frame 40 Can (stator can)
41 can (rotor can)
42 Reinforcing pipes 42A, 42B Divided frame 46 Flow hole (outflow hole)
50 Connecting pipe 51 Communication cover 51a Opening end 51b Connection hole 53 Sealing member 60 Can (stator can)
P pump M motor unit SC stator chamber C1 space C2 space

Claims (7)

With multiple canned motor pumps,
A connecting pipe for connecting the plurality of can motor pumps is provided.
Each of the plurality of cand motor pumps includes a motor casing.
The motor casing has flow holes formed at both ends thereof for allowing liquid to pass through, and houses the motor.
A water supply device in which a plurality of motor casings are communicated with each other by the connecting pipe. The motor casing includes an end cover that constitutes one end of the motor casing.
The water supply device according to claim 1, wherein each of the plurality of can motor pumps includes a communication cover for connecting the connecting pipe to the flow hole formed in the end cover. The motor casing comprises a motor frame arranged around the motor and connected to the end cover.
The communication cover covers the end cover and the motor frame.
The water supply device according to claim 2, wherein the connecting pipe is connected to the communication cover at a position opposite to the end cover. The water supply device according to any one of claims 1 to 3, wherein the motor casing includes a non-conductive can arranged between the motor rotor of the motor and the motor stator of the motor. .. The water supply device according to claim 4, wherein the motor casing includes a reinforcing pipe for reinforcing the can. The water supply device
The suction pipe and the discharge pipe connected to the plurality of can motor pumps,
The suction pipe and the bypass pipe connected to the discharge pipe are provided.
The water supply device according to any one of claims 1 to 5, wherein the connecting pipe is connected to the bypass pipe. The water supply device according to any one of claims 1 to 6, wherein the water supply device includes an inverter arranged adjacent to the plurality of can motor pumps.

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