JP2010216470A - Pump and use method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump generally miniaturizable and prevented from being damaged due to vibration. <P>SOLUTION: In this pump 11, a suction side chamber and a discharge side chamber are formed in a casing 12, and a shaft-through hole through which a spindle 17 extends is formed in the casing 12. A shaft seal part for sealing between the spindle 17 and the casing 12 is provided to the shaft-through hole. A water-sealing passage 38 for sealing the shaft seal part by supplying the water in the discharge side chamber to the shaft seal part is formed in the casing 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spiral pump or the like having a suction side chamber and a discharge side chamber in a casing, and a method of using the pump.

  Conventionally, as this type of pump, for example, as shown in FIG. 25, a casing 101 is provided with a shaft through-hole 103 through which the main shaft 102 passes, and the shaft through-hole 103 is sealed between the main shaft 102 and the casing 101. Some are provided with a shaft seal 104 to be stopped. Outside the casing 101, an external pipe 106 that supplies water in the discharge-side spiral chamber 105 to the shaft seal portion 104 and seals the shaft seal portion 104 is provided. One end of the external pipe 106 communicates with the discharge-side spiral chamber 105 through a joint 107, and the other end of the external pipe 106 communicates with the shaft seal portion 104.

  According to this, a part of the water discharged to the outside through the inside of the discharge side spiral chamber 105 is supplied as shaft seal water from the inside of the discharge side spiral chamber 105 to the shaft seal portion 104 through the external pipe 106. . As a result, self-sealing water is performed at the shaft seal portion 104, so that external air enters the casing 101 from the shaft seal portion 104 or water in the casing 101 leaks from the shaft seal portion 104 to the outside of the casing 101. Can be prevented.

  Note that the pump in which the external pipe 106 is provided outside the casing 101 as described above is described in Patent Document 1 below.

Japanese Utility Model Sho 61-116197

  However, in the above-described conventional format, since the external pipe 106 is provided in the casing 101, there is a problem in that the pump 100 as a whole becomes large and the space volume necessary for installing the pump 100 increases.

Moreover, there is a problem that the external pipe 106 is vibrated and damaged due to leakage due to poor construction or vibration during pump operation due to poor construction.
An object of the present invention is to provide a pump and a method of using the pump that can reduce the size of the entire pump and prevent damage due to leakage or vibration due to poor construction.

In order to achieve the above object, the first invention is provided with a suction side chamber and a discharge side chamber in a casing,
The casing is provided with a shaft through hole through which the main shaft passes,
The casing is formed by joining the first casing body and the second casing body, which are divided by a plane including the main shaft, via a joint surface,
A pump provided with a shaft sealing portion for sealing between the main shaft and the casing in the shaft through hole,
A sealing passage for supplying liquid in the discharge side chamber to the shaft sealing portion and liquid-sealing the shaft sealing portion is formed in the wall thickness of the casing.

  According to this, when the main shaft rotates and the pump operates, the liquid sucked into the suction side chamber is discharged from the discharge side chamber to the outside of the casing. At this time, a part of the liquid in the discharge side chamber is supplied as a shaft sealing liquid to the shaft sealing portion through the sealing liquid passage, so that the shaft sealing portion is liquid sealed. Accordingly, it is possible to prevent external air from entering the casing from the shaft seal portion, or to suppress the amount of liquid in the casing leaking from the shaft seal portion to the outside of the casing.

  Further, since the sealed liquid passage is formed inside the casing, the external piping in that portion is unnecessary, and the entire pump can be reduced in size. Furthermore, damage and leakage of external piping due to vibration can be prevented.

In the pump according to the second aspect of the invention, the sealing liquid passage has at least a groove-shaped first supply passage formed on the joint surface of the first casing body,
The first supply passage is provided inside the wall thickness of the casing in a state where the first casing body and the second casing body are joined.

According to this, since the sealing liquid passage can be formed inside the thickness of the casing by the groove processing, the processing for forming the sealing liquid passage becomes easy.
In the pump according to the third aspect of the present invention, the first supply passage communicates with the discharge side chamber on the upstream side and with the shaft seal portion on the downstream side.

According to this, since a part of the liquid in the discharge side chamber is supplied as the shaft sealing liquid to the shaft sealing portion through the first supply passage of the sealing liquid passage, the shaft sealing portion is liquid sealed.
In the pump according to the fourth aspect of the invention, the sealing passage has a second supply passage formed in the second casing body,
The second supply passage communicates with the discharge side chamber on the upstream side and with the first supply passage on the downstream side,
The first supply passage communicates with the second supply passage on the upstream side and communicates with the shaft seal portion on the downstream side.

According to this, a part of the liquid in the discharge side chamber flows as the shaft sealing liquid through the second supply passage through the first supply passage and is supplied from the first supply passage to the shaft sealing portion.
In the pump according to the fifth aspect of the present invention, the first casing body is provided with a relief passage branched from the first supply passage,
The downstream side of the escape passage communicates with the suction side chamber.

  According to this, when a part of the liquid in the discharge side chamber flows through the first supply passage, the liquid flows separately into the first supply passage and the escape passage. Among these, the liquid flowing through the first supply passage is supplied to the shaft seal portion as a shaft seal liquid. Further, the liquid flowing through the escape passage is supplied into the suction side chamber. As a result, the flow rate of the liquid flowing through the sealing liquid passage increases, and the flow velocity increases accordingly. Therefore, the pressure reducing means can be provided in the sealing liquid passage to sufficiently reduce the pressure. Therefore, even if the pressure in the discharge side chamber is higher than a predetermined pressure suitable for liquid sealing, by providing a pressure reducing means in the sealing passage, the shaft sealing liquid supplied from the discharge side chamber to the shaft sealing portion The pressure can be sufficiently reduced to a predetermined pressure.

In the pump according to the sixth invention, a relief passage is formed in the first casing body,
The downstream end of the second supply passage branches into a first supply passage and a relief passage;
The downstream side of the escape passage communicates with the suction side chamber.

  According to this, a part of the liquid in the discharge side chamber passes through the second supply passage and flows separately from the second supply passage into the first supply passage and the escape passage. Among these, the liquid flowing through the first supply passage is supplied to the shaft seal portion as a shaft seal liquid. Further, the liquid flowing through the escape passage is supplied into the suction side chamber. As a result, the flow rate of the liquid flowing through the second supply passage is increased, and the flow velocity is increased accordingly. Therefore, the pressure reduction means can be provided in the sealed liquid passage to sufficiently reduce the pressure. Therefore, even if the pressure in the discharge side chamber is higher than a predetermined pressure suitable for liquid sealing, by providing a pressure reducing means in the sealing passage, the shaft sealing liquid supplied from the discharge side chamber to the shaft sealing portion The pressure can be sufficiently reduced to a predetermined pressure.

In the pump according to the seventh aspect of the invention, the sealing passage is provided with a pressure reducing means for reducing the pressure of the shaft sealing liquid flowing from the discharge side chamber to the shaft sealing portion to a predetermined pressure.
According to this, when the pressure in the discharge side chamber is higher than a predetermined pressure suitable for liquid sealing the shaft seal portion, the shaft seal liquid supplied from the discharge side chamber to the shaft seal portion is provided by providing a pressure reducing means. Is reduced to a predetermined pressure. Thereby, a shaft seal part can be sealed with the shaft seal liquid of an optimal pressure.

Further, since the pressure reducing means is provided in the sealed liquid passage, it is not exposed to the outside of the casing, thereby further reducing the size of the entire pump.
In the pump according to the eighth aspect of the invention, the pressure reducing means is an orifice member fitted in the sealed passage.

According to this, the decompression means can be provided in the sealed liquid passage without significantly increasing the number of processing steps for the sealed liquid passage.
The pump according to the ninth aspect of the present invention has a foreign matter capturing member provided in the sealing passage.

  According to this, solid matters such as dust mixed in the shaft sealing liquid flowing through the sealing liquid passage are captured by the foreign matter capturing member. Thereby, it is possible to prevent clogging of the solid passage such as dust in the sealed liquid passage.

In the pump according to the tenth aspect of the present invention, a backwashing channel having one end opened at the end face of the casing and the other end communicating with the shaft seal portion is formed in the casing.
According to this, when the sealing liquid passage is backwashed, backwashing water is supplied to one end of the backwashing channel. As a result, the backwash water flows through the backwash flow path, passes through the shaft sealing portion, flows back through the sealing liquid passage, and is discharged to the discharge side chamber. As a result, the sealing liquid passage is back-washed, and solids such as dust in the sealing liquid passage are excluded.

The eleventh invention is a method of using the pump according to any one of the first to tenth inventions,
When the sealing liquid passage is not used, the sealing liquid passage is sealed by providing a closing member in the sealing liquid passage.

  According to this, when a part of the liquid in the discharge side chamber becomes unusable as a shaft seal liquid due to a change in operating conditions, the internal seal passage is sealed with a closing member without replacing the pump, The pump can be operated using the shaft seal liquid.

  According to the present invention, the entire pump can be reduced in size. In addition, it is possible to prevent external piping from being damaged due to leakage due to poor construction or vibration.

It is a side view of the pump in the 1st embodiment of the present invention. It is a bottom view of the casing body of the upper part of a pump same as the above. It is a top view of the casing body of the lower part of a pump same as the above. It is an expanded sectional view of the shaft seal part of the pump. It is a perspective view of the sealing water passage of a pump same as the above. It is a longitudinal cross-sectional view of the sealed water passage of the pump. It is a perspective view of the sealing water passage of the pump in the 2nd embodiment of the present invention. It is a partially expanded side view of the pump in the 3rd Embodiment of this invention. It is a top view of the casing body of the lower part of a pump same as the above. It is a partially expanded top view of the casing body of the lower part of the pump. It is a perspective view of a sealing water passage and a relief passage of a pump. It is a perspective view of the sealing water passage and escape passage of a pump in a 4th embodiment of the present invention. It is a longitudinal cross-sectional view of the sealing water passage of the pump in the 5th Embodiment of this invention. It is a figure of the 2nd supply path of the sealing water path of the pump in the 6th Embodiment of this invention, (a) is a longitudinal cross-sectional view, (b) is a XX arrow line view in (a). . It is a top view of the casing body of the lower part of the pump in the 7th Embodiment of this invention. It is a partially expanded top view of the casing body of the lower part of the pump. It is a perspective view of the sealing water passage of a pump same as the above. FIG. 3 is a partially enlarged longitudinal sectional view of a sealed water passage of the pump. It is a top view of the casing body of the lower part of the pump in the 8th Embodiment of this invention. It is a partially expanded top view of the casing body of the lower part of the pump. It is a perspective view of the sealing water passage of a pump same as the above. It is a longitudinal cross-sectional view of the sealing water passage of the pump in the 9th Embodiment of this invention. It is an expanded sectional view of the shaft seal part of the pump in the 10th embodiment of the present invention. It is a perspective view of the water seal passage of the pump in the 11th embodiment of the present invention. It is a figure of the conventional pump.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 to 3, reference numeral 11 denotes a double suction centrifugal pump. A suction port 13 and a discharge port 14 are formed in the casing 12. In the casing 12, a discharge side chamber 15 (vortex chamber) that communicates with the discharge port 14 and a suction side chamber 16 that is located on both the left and right sides of the discharge side chamber 15 and communicates with the suction port 13 are formed.

  The casing 12 is provided with a pair of left and right shaft through holes 18 through which the main shaft 17 passes. A shaft sealing portion 19 that seals between the main shaft 17 and the casing 12 is provided in the shaft through hole 18. As shown in FIG. 4, the shaft sealing portion 19 includes a plurality of annular gland packings 20 that seal between the inner peripheral surface of the shaft through hole 18 and the outer peripheral surface of the main shaft 17, and an annular sealing ring 21. And have. An inner circumferential groove 22 is formed over the entire circumference on the inner circumferential surface of the sealing ring 21, and an outer circumferential groove 23 is formed over the entire circumference on the outer circumferential surface of the sealing ring 21. The sealing ring 21 is formed with a plurality of radial communication holes 24 communicating with the inner circumferential groove 22 and the outer circumferential groove 23. As shown in FIG. 3, the main shaft 17 is provided with an impeller 26, and the impeller 26 is accommodated in the discharge side chamber 15. The main shaft 17 is rotationally driven by a driving device (not shown) such as a motor.

  As shown in FIGS. 1 to 3, the casing 12 includes a lower casing body 29 (an example of a first casing body) divided by a horizontal plane (an example of a plane including the main axis) including the axis 27 of the main shaft 17. It consists of an upper casing body 28 (an example of a second casing body).

  The upper casing body 28 has an upper flange portion 30 and an upper joint surface 31 at the lower end. The lower casing body 29 has a lower flange portion 32 and a lower joint surface 33 at the upper end. The upper casing body 28 and the lower casing body 29 are connected to each other by a plurality of bolts 34 (an example of connecting means) with the joint surfaces 31 and 33 joined together. A seal groove 35 is formed in the lower joint surface 33, and a rubber-like string-like seal member 36 that seals between the joint surfaces 31 and 33 is fitted in the seal groove 35. The seal member 36 is not limited to a string shape, and may be, for example, a sheet-like gasket.

  Inside the wall thickness of the casing 12, a pair of right and left sealed passages 38 (sealed) that supply water (an example of a liquid) in the discharge side chamber 15 to the shaft sealing portion 19 and seal the shaft sealing portion 19 with water (liquid sealing). An example of the liquid passage is formed.

  As shown in FIGS. 1 to 3, 5, and 6, each sealed water passage 38 is a first supply passage formed on the joint surface 33 of the lower casing body 29 (an example of the other casing body). 40 and a second supply passage 39 formed in the wall thickness of the upper casing body 28.

  Among these, as shown in FIGS. 1, 3, 5, and 6, the first supply passage 40 has a rectangular cross-section with an open upper surface in a state where the upper and lower casing bodies 28 and 29 are separated. In the state in which the upper and lower casing bodies 28 and 29 are joined, the groove is a passage provided inside the thickness of the casing 12. Here, the passage provided inside the thickness of the casing 12 refers to a passage having a longitudinal direction in a direction substantially orthogonal to the thickness direction, and a passage that simply passes through in the thickness direction is applicable. do not do. The first supply passage 40 has one end portion (upstream side) communicating with the lower end (downstream side) of the second supply passage 39 and the other end portion (downstream end) as shown in FIG. 21 communicates with the outer circumferential groove 23.

  As shown in FIGS. 1, 2, 5, and 6, the second supply passage 39 is a hole having a circular cross section, and a lateral hole portion 41 whose inner end (upstream side) communicates with the discharge side chamber 15. And the lower end (downstream side) has a vertical hole portion 42 communicating with the first supply passage 40. The vertical hole portion 42 has an upper end communicating with the horizontal hole portion 41 and a lower end communicating with the first supply passage 40. Further, the outer end of the lateral hole 41 is closed by a plug 43.

Hereinafter, the operation of the above configuration will be described.
By rotating the main shaft 17, the impeller 26 rotates, and water sucked into the suction side chambers 16 from the suction port 13 is discharged from the discharge port 14 through the discharge side chamber 15. At this time, a part of the water in the discharge side chamber 15 flows as the shaft seal water (an example of the shaft seal liquid) through the second supply passage 39 of the seal passage 38 and the first supply passage 40. One supply passage 40 is supplied to the outer circumferential groove 23 of the sealing ring 21 over the entire circumference, and further, is supplied to the inner circumferential groove 22 through the communication hole 24 over the entire circumference. As a result, the shaft seal water is supplied to the shaft seal portion 19, and the shaft seal portion 19 is water sealed (liquid sealed), and a small amount of shaft seal water is generated between the inner peripheral surface of the gland packing 20 and the outer peripheral surface of the main shaft 17. It flows in the direction of the shaft center 27 and leaks slightly to the outside of the shaft seal portion 19. Thereby, it is possible to prevent external air from entering the casing 12 from the shaft seal portion 19, or to suppress the amount of water in the casing 12 leaking from the shaft seal portion 19 to the outside of the casing 12. .

  Further, since the sealed water passage 38 includes a second supply passage 39 formed in the upper casing body 28 and a first supply passage 40 formed in the joint surface 33 of the lower casing body 29, external piping is used. It becomes unnecessary, and the pump 11 whole can be reduced in size. Furthermore, it is possible to prevent external piping from being damaged due to leakage due to poor construction or vibration.

When sealing the shaft seal portion 19 as described above, it is necessary to supply the shaft seal portion 19 with shaft seal water having a predetermined water pressure that is optimal for sealing water. In the said 1st Embodiment, it is effective when the water pressure in the discharge side chamber 15 is the same or substantially the same as the predetermined water pressure (for example, 200-400 kPa) optimal for the said sealing water.
(Second Embodiment)
Further, when the water pressure in the discharge side chamber 15 is higher than a predetermined water pressure optimum for the sealed water, in a second embodiment described below, as shown in FIG. 47 (an example of a decompression unit) may be provided.

  The orifice member 47 includes a substantially cylindrical base 48 and an L-shaped flow hole 49 having first and second openings 49a and 49b that open to the upper surface and the outer peripheral surface of the base 48. Have. The substantially upper half of the orifice member 47 is inserted into the lower end portion of the vertical hole portion 42 of the second supply passage 39, and the substantially lower half of the orifice member 47 is fitted into one end portion of the first supply passage 40. The first opening 49 a communicates with the second supply passage 39, and the second opening 49 b communicates with the first supply passage 40. The orifice member 47 is prevented from rotating by a rotation stop means (not shown) such as a pin so as not to rotate in the supply passages 39 and 40.

  According to this, a part of the water in the discharge side chamber 15 flows as the shaft sealing water through the second supply passage 39, flows through the first supply passage 40 through the flow hole 49 of the orifice member 47, and seals the water. It is supplied to the outer peripheral side groove 23 of the ring 21. At this time, the pressure (for example, 400 to 800 kPa) of the shaft seal water introduced from the inside of the discharge side chamber 15 is lowered to a predetermined pressure (for example, 200 to 400 kPa) by the orifice member 47, and the shaft seal is sealed with the shaft seal water of the optimum pressure. The part 19 can be sealed with water.

Further, since the orifice member 47 is provided in the sealed water passage 38, it is not exposed to the outside of the casing 12, thereby further reducing the size of the pump 11 as a whole. Further, by using the orifice member 47 that does not require a complicated shape of the groove of the first supply passage 40 as the decompression means, a significant increase in the number of processing steps can be suppressed, and the sealed water passage can be easily performed. 38 can be provided.
(Third embodiment)
Next, a third embodiment will be described with reference to FIGS.

  A relief passage 51 is formed in the lower casing body 29, and the downstream end of the vertical hole portion 42 of the second supply passage 39 is branched into a first supply passage 40 and a relief passage 51. The escape passage 51 has a first escape passage 52 and a second escape passage 53. The first escape passage 52 is formed in the joint surface 33 of the lower casing body 29, and in the state where the upper and lower casing bodies 28 and 29 are separated, is a rectangular groove whose upper surface is opened, In the state where the upper and lower casing bodies 28 and 29 are joined, the passage is provided inside the casing 12. One end of the first escape passage 52 communicates with the vertical hole portion 42 and the first supply passage 40. The second escape passage 53 is a hole having a circular cross section formed inside the wall of the lower casing body 29, and communicates with the other end of the first escape passage 52 and the inside of the suction side chamber 16. Yes.

  As shown in FIG. 11, the sealed water passage 38 is provided with a first orifice member 55 (an example of a decompression unit). The first orifice member 55 is a T-shaped flow hole 57 having a substantially cylindrical base material 56 and first to third openings 57 a to 57 c that open to the upper surface and the outer peripheral surface of the base material 56. And have. The substantially upper half of the first orifice member 55 is inserted into the lower end portion of the vertical hole portion 42 of the second supply passage 39, and the substantially lower half of the first orifice member 55 is fitted into one end portion of the first supply passage 40. It is. The first opening 57a communicates with the second supply passage 39, the second opening 57b communicates with the first supply passage 40, and the third opening 57c communicates with the first escape passage 52. Communicate.

  The first escape passage 52 is provided with a second orifice member 59 (an example of a decompression unit). The second orifice member 59 has a substantially columnar base 60 and a linear flow hole 61 provided with first and second openings 61 a and 61 b that open to the outer peripheral surface of the base 60. is doing. Incidentally, the first and second orifice members 55 and 59 are prevented from rotating by a rotation stop means (not shown) such as a pin so as not to rotate in the respective passages 39, 40 and 51. Further, the rotation stop means also functions to prevent the second orifice member 59 from coming off.

Hereinafter, the operation of the above configuration will be described.
A part of the water in the discharge side chamber 15 flows through the second supply passage 39, branches and flows into the first supply passage 40 and the escape passage 51 through the flow hole 57 of the first orifice member 55. At this time, the water flowing into the first supply passage 40 is supplied to the outer peripheral groove 23 of the sealing ring 21 as shaft sealing water. Further, the water flowing into the escape passage 51 is supplied into the suction side chamber 16 through the flow hole 61 of the second orifice member 59.

As a result, the flow rate of the water flowing through the second supply passage 39 increases, and the flow velocity increases accordingly, so that the first orifice member 55 can sufficiently reduce the pressure. If the constant determined by the shape of the first orifice member 55 is f, the flow rate of the water flowing through the second supply passage 39 is W, and the amount of pressure reduction (pressure loss) is ΔP, The pressure reduction amount ΔP is proportional to the square of the flow rate W.
ΔP = f × W ²
Therefore, even when the pressure in the discharge side chamber 15 is higher than a predetermined pressure suitable for water sealing, the pressure of the shaft seal water supplied from the discharge side chamber 15 to the shaft seal portion 19 is sufficiently increased to the predetermined pressure. Can be reduced.

Further, since the flow rate of the water flowing through the escape passage 51 is restricted by the second orifice member 59, the pressure of the shaft seal water is set to the optimum pressure by the balance between the first orifice member 55 and the second orifice member 59. Can be adjusted. Further, the second orifice member 59 can be easily provided in the first escape passage 52.
(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG.

  In the fourth embodiment, a third orifice member 64 is inserted into the vertical hole portion 42 of the second supply passage 39 of the third embodiment. The third orifice member 64 has a substantially cylindrical base 65, a small flow hole 66 b having a small opening 66 a that opens at one end face of the base 65, and an opening at the other end face of the base 65. It consists of a large flow hole 66d provided with a large opening 66c. The small flow hole 66b and the large flow hole 66d communicate with each other in the base material 65, and the diameter of the small flow hole 66b is smaller than the diameter of the large flow hole 66d.

  According to this, when the pressure in the discharge side chamber 15 is higher than a predetermined pressure suitable for water sealing and the difference between the pressure in the discharge side chamber 15 and the predetermined pressure is large, the third is inserted into the vertical hole portion 42. By increasing the number of the orifice members 64, the pressure of the shaft seal water supplied from the inside of the discharge side chamber 15 to the shaft seal portion 19 can be adjusted and accurately reduced to the predetermined pressure.

  Further, when the difference between the pressure in the discharge side chamber 15 and the predetermined pressure is small, the number of the third orifice members 64 inserted into the vertical hole portions 42 is reduced to reduce the number of the third orifice members 64 from the discharge side chamber 15 to the shaft seal portion 19. The pressure of the supplied shaft seal water can be adjusted and accurately lowered to the predetermined pressure. In FIG. 12, two third orifice members 64 are provided as an example. However, a single number or a plurality other than two may be provided.

  In the second to fourth embodiments, as shown in FIGS. 7, 11, and 12, the substantially cylindrical orifice members 47, 55, 59, and 64 are used. A polygonal column-shaped orifice member may be used. In the case of a polygonal column-shaped orifice member, the orifice member does not rotate in the passage, and therefore it is not necessary to provide a separate stopping means for the orifice member.

In the second to fourth embodiments, the orifice members 47, 55, 59, and 64 are used as an example of the pressure reducing means. However, as shown in the fifth and sixth embodiments below, the orifice members are used. It may not be.
(Fifth embodiment)
That is, in the fifth embodiment, as shown in FIG. 13, a first throttle portion 68 (an example of a decompression unit) that reduces the flow path cross-sectional area is formed in the lateral hole portion 41 of the second supply passage 39. In the vertical hole portion 42, a second throttle portion 69 (an example of a decompression unit) that reduces the cross-sectional area of the flow path is formed.

  The first throttle portion 68 has a smaller diameter than the horizontal hole portion 41, and the horizontal hole portion 41 communicates with the discharge side chamber 15 via the first throttle portion 68. The second throttle portion 69 has a smaller diameter than the vertical hole portion 42, and the vertical hole portion 42 communicates with the horizontal hole portion 41 via the second throttle portion 69.

According to this, a part of the water in the discharge side chamber 15 flows as the shaft seal water from the second supply passage 39 through the first supply passage 40 and is supplied to the outer circumferential groove 23 of the seal ring 21. At this time, the water pressure of the shaft seal water flowing through the second supply passage 39 is reduced to a predetermined pressure by the first and second throttle portions 68 and 69, and thereby the shaft seal portion is sealed with the shaft seal water at the optimum pressure. 19 can be water sealed. In the present embodiment, the joint surface 31 of the upper casing body 28 and the joint surface 33 of the lower casing body 29 are sealed by a sheet-like packing 70.
(Sixth embodiment)
Further, in the sixth embodiment, as shown in FIG. 14, a throttle portion 71 (an example of a decompression unit) that protrudes upward is formed on the bottom surface of the first supply passage 40. Both end surfaces 71a of the throttle portion 71 in the length direction of the first supply passage 40 are formed in an arc shape in plan view.

  According to this, since the height h1 from the upper end of the throttle portion 71 to the lower joint surface 33 is reduced more than the height h2 from the bottom surface of the first supply passage 40 to the lower joint surface 33, the throttle portion 71. As a result, the cross-sectional area of the first supply passage 40 is reduced.

  Therefore, when a part of the water in the discharge side chamber 15 flows as the shaft seal water from the second supply passage 39 through the first supply passage 40 and is supplied to the outer peripheral groove 23 of the seal ring 21, the first The pressure of the shaft seal water flowing through the supply passage 40 is reduced to a predetermined pressure by the throttle portion 71. Thereby, the shaft seal part 19 can be sealed with the shaft seal water of an optimal pressure.

In the sixth embodiment, the throttle portion 71 is provided on the bottom surface of the first supply passage 40. Similarly, the throttle portion 71 is provided in the escape passage 51 and the water flowing through the escape passage 51 is provided. The flow rate may be adjusted.
(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIGS.

  The first supply passage 40 and the second supply passage 39 are formed in the same manner as in the first embodiment described above. In the lower casing body 29, an escape passage 73 branched from the first supply passage 40 is formed. The downstream end of the escape passage 73 communicates with the suction side chamber 16.

  The escape passage 73 is formed on the joint surface 33 of the lower casing body 29, and is a rectangular groove having an open upper surface when the upper and lower casing bodies 28, 29 are separated from each other. In the state in which the casing bodies 28 and 29 are joined, the passage is provided inside the casing 12.

  First and second orifice members 74 and 75 (an example of a decompression unit) are fitted into the first supply passage 40 of the sealed water passage 38, and a third orifice member 76 (an example of the decompression unit) is inserted into the escape passage 73. ) Is inserted. The first orifice member 74 has a rectangular parallelepiped (or may be cubic) base material 77 and first to third openings 78a to 78c that open to the upper surface and both side surfaces of the base material 77. And a T-shaped flow hole 78. The first opening 78 a communicates with the vertical hole portion 42 of the second supply passage 39, and the second opening 78 b communicates with the first supply passage 40.

  The second orifice member 75 has a rectangular parallelepiped (or may be cubic) base material 80, and a linear shape including first and second openings 81a and 81b that open on both side surfaces of the base material 80. It has a circulation hole 81. The third orifice member 76 has the same configuration as the second orifice member 75.

  As shown in FIG. 18, an immersion portion 83 that is one step deeper than the bottom surface 82 of the passages 40, 73 is formed at the bottom of the predetermined portion of the first supply passage 40 and the bottom of the predetermined portion of the escape passage 73. Yes. The first to third orifice members 74 to 76 are fitted in the immersion portions 83, respectively.

Hereinafter, the operation of the above configuration will be described.
Part of the water in the discharge side chamber 15 flows through the second supply passage 39, flows through the first supply passage 40 through the flow hole 78 of the first orifice member 74, and flows through the second orifice member 75. After passing through the hole 81, it branches and flows into the first supply passage 40 and the escape passage 73. At this time, the water flowing through the first supply passage 40 is supplied to the outer peripheral groove 23 of the sealing ring 21 as shaft sealing water. The water flowing through the escape passage 73 is supplied into the suction side chamber 16 through the flow hole 81 of the third orifice member 76.

  As a result, the flow rate of the water flowing through the first and second supply passages 39 and 40 increases, and the flow velocity increases accordingly. Therefore, the pressure is sufficiently reduced by the first and second orifice members 74 and 75. Can do. Therefore, even when the pressure in the discharge side chamber 15 is higher than a predetermined pressure suitable for water sealing, the pressure of the shaft seal water supplied from the discharge side chamber 15 to the shaft seal portion 19 is sufficiently increased to the predetermined pressure. Can be reduced.

  Further, since the flow rate of the water flowing through the escape passage 73 is throttled by the third orifice member 76, the shaft seal water pressure is adjusted to the optimum pressure by the balance of the first to third orifice members 74 to 76. Can do.

  Further, since each of the first to third orifice members 74 to 76 has a rectangular parallelepiped shape, the orifice members 74 to 76 can be prevented from rotating in the passages 40 and 73. Furthermore, since the first to third orifice members 74 to 76 are fitted in the immersing portions 83, the orifice members 74 to 76 can be prevented from shifting in the flow direction.

  In the above embodiment, one second orifice member 75 and one third orifice member 76 are provided. However, a plurality of second orifice members 75 or a plurality of third orifice members 76 are provided. It may be provided to adjust the pressure of the shaft seal water. Alternatively, at least one of the first to third orifice members 74 to 76 may not be provided.

In each of the above embodiments, the lower casing body 29 is taken as an example of the first casing body, the first supply passage 40 and the escape passages 51 and 73 are formed in the lower casing body 29, and the upper casing body 28 is replaced with the upper casing body 28. Although the second supply passage 39 is formed in the upper casing body 28 as an example of the second casing body, the upper casing body 28 is taken as an example of the first casing body and the first casing body 28 The supply passage 40 and the escape passages 51 and 73 may be formed, the lower casing body 29 may be an example of the second casing body, and the second supply passage 39 may be formed in the lower casing body 29.
(Eighth embodiment)
In each of the above embodiments, the second supply passage 39 is formed in the upper casing body 28. However, in the eighth embodiment described below, as shown in FIGS. The second supply passage 39 is not formed in the body 28, and the first supply passage 40 and the escape passage 73 are formed in the lower casing body 29.

  The first supply passage 40 has one end portion (upstream side) communicating with the discharge side chamber 15 and the other end portion (downstream side) communicating with the outer peripheral groove 23 of the sealing ring 21. The escape passage 73 branches off from the first supply passage 40, and the downstream end thereof communicates with the suction side chamber 16.

  Each of the first supply passage 40 and the escape passage 73 is formed on the joint surface 33 of the lower casing body 29, and in the state where the upper and lower casing bodies 28 and 29 are separated, the square whose upper surface is opened. In the state where the upper and lower casing bodies 28 and 29 are joined, the groove is formed into a passage provided inside the casing 12.

  A first orifice member 85 (an example of a decompression unit) is fitted into the first supply passage 40, and a second orifice member 86 (an example of the decompression unit) is fitted into the escape passage 73. Each of the first and second orifice members 85 and 86 is a rectangular parallelepiped (or may be cubic) base material 87 and first and second openings 88a and 88b that open on both side surfaces of the base material 87. And a linear flow hole 88 provided with

  Similarly to the above-described seventh embodiment, the first supply passage 40 and the escape passage 73 are respectively provided with immersion portions 83 (not shown), and the first and second orifice members 85 are formed. , 86 are fitted in the immersion part 83, respectively.

Hereinafter, the operation of the above configuration will be described.
A part of the water in the discharge side chamber 15 flows through the first supply passage 40 and passes through the flow hole 88 of the first orifice member 85, and then branches into the first supply passage 40 and the escape passage 73. Flowing. At this time, the water flowing through the first supply passage 40 is supplied to the outer peripheral groove 23 of the sealing ring 21 as shaft sealing water. The water flowing through the escape passage 73 is supplied into the suction side chamber 16 through the flow hole 88 of the second orifice member 86.

  As a result, the flow rate of the water flowing through the first supply passage 40 increases, and the flow velocity increases accordingly, so that the first orifice member 85 can sufficiently reduce the pressure. Therefore, even when the pressure in the discharge side chamber 15 is higher than a predetermined pressure suitable for water sealing, the pressure of the shaft seal water supplied from the discharge side chamber 15 to the shaft seal portion 19 is sufficiently increased to the predetermined pressure. Can be reduced.

  Further, since the flow rate of the water flowing through the escape passage 73 is restricted by the second orifice member 86, the pressure of the shaft seal water is adjusted to the optimum pressure by the balance between the first and second orifice members 85 and 86. Can do.

  In the above embodiment, one each of the first orifice member 85 and the second orifice member 86 is provided. However, a plurality of first orifice members 85 or a plurality of second orifice members 86 are provided. It may be provided to adjust the pressure of the shaft seal water or to adjust the flow rate of the water flowing through the escape passage 73. Alternatively, at least one of the first and second orifice members 85 and 86 may not be provided.

In the above embodiment, the lower casing body 29 is taken as an example of the first casing body, the first supply passage 40 and the escape passage 73 are formed in the lower casing body 29, and the upper casing body 28 is replaced with the second casing body 28. Although the casing body is an example, the upper casing body 28 is an example of the first casing body, the first supply passage 40 and the escape passage 73 are formed in the upper casing body 28, and the lower casing body 29 is the first casing body 29. It is good also as an example of 2 casing bodies.
(Ninth embodiment)
The ninth embodiment of the present invention will be described below with reference to FIG.

A strainer 91 (an example of a foreign matter capturing member) is provided in the lateral hole portion 41 of the second supply passage 39.
According to this, solid matter such as dust mixed in the shaft seal water flowing through the seal water passage 38 is captured by the strainer 91. Thereby, it is possible to prevent the solid matter such as dust from being clogged in the region downstream of the lateral hole portion 41. Further, by removing the plug 43, the strainer 91 can be easily taken out, and the strainer 91 can be replaced or cleaned. The strainer 91 may be provided in the vertical hole portion 42 or may be provided in the first supply passage 40.
(Tenth embodiment)
The tenth embodiment of the present invention will be described below with reference to FIG.

  A backwash channel 93 is formed in the upper casing body 28. One end of the backwashing channel 93 is open to the end surface 94 of the upper casing body 28. The other end of the backwashing channel 93 communicates with the outer circumferential groove 23 of the sealing ring 21. Note that one end of the backwash channel 93 is closed by a detachable plug 95 (an example of a plug).

  According to this, when the sealed water passage 38 is backwashed, the plug 95 is removed from one end of the backwashing channel 93 and a backwashing water supply pipe or the like (not shown) is connected to one end of the backwashing channel 93. Then, the backwash water 96 is supplied to one end of the backwash channel 93. As a result, the backwash water 96 flows through the backwash flow passage 93 and reaches the outer circumferential groove 23 of the sealing ring 21, flows through the outer circumferential groove 23, and flows through the inner circumferential groove 22 through the communication hole 24. The first supply passage 40, the vertical hole portion 42, and the horizontal hole portion 41 of the sealed water passage 38 flow backward from the side groove 22 and the outer peripheral side groove 23, and are discharged to the discharge side chamber 15. Thereby, the sealed water passage 38 is back-washed, and solids such as dust in the sealed water passage 38 are removed.

After the backwashing is completed, one end of the backwashing channel 93 is closed with a plug 95 attached.
In the tenth embodiment, the backwash channel 93 is formed in the upper casing body 28, but may be formed in the lower casing body 29.
(Eleventh embodiment)
The eleventh embodiment of the present invention will be described below with reference to FIG.

  When the sealed water passage 38 is not used, a block body 98 (an example of a closing member) is provided in the first supply passage 40, the escape passage 73, etc., and the first supply passage 40 and the escape passage 73 are sealed. Thereby, the shaft seal water is not supplied from the discharge side chamber 15 to the seal ring 21.

  Further, in the eleventh embodiment, when the backwashing channel 93 shown in FIG. 23 is formed, shaft sealing water is supplied from the outside of the pump 11 to the shaft sealing part 19 using the backwashing channel 93. Can be supplied. At this time, by providing the block body 98 as described above, the shaft sealing water supplied from the backwashing flow path 93 to the shaft sealing portion 19 is blocked by the block body 98, and thus the first supply passage 40. And the escape passage 73 do not flow backward.

  In each of the above embodiments, the orifice member may be formed of an elastic material such as rubber so that the pressure reduction amount by the orifice member can be adjusted, and the diameter of the flow hole can be adjusted by applying an external force. .

In each said embodiment, you may have an external piping part in part in the range which does not produce the installation space of a pump 11, or a vibration problem.
In each of the above-described embodiments, the double suction centrifugal pump 11 is described as an example of the pump. However, other types of pumps such as a multi-stage single suction centrifugal pump may be used.

11 Pump 12 Casing 15 Discharge side chamber 16 Suction side chamber 17 Main shaft 18 Shaft through hole 19 Shaft seal portion 28 Upper casing body (second casing body)
29 Lower casing body (first casing body)
31, 33 Joint surface 38 Sealed water passage (sealed liquid passage)
39 Second supply passage 40 First supply passage 47, 55, 59, 64, 74 to 76, 85, 86 Orifice member (pressure reducing means)
51,73 Escape passage 68,69,71 Restriction part (pressure reduction means)
91 Strainer (foreign material capturing member)
93 Backwashing channel 98 Block body (closing member)

Claims (11)

A suction side chamber and a discharge side chamber are provided in the casing,
The casing is provided with a shaft through hole through which the main shaft passes,
The casing is formed by joining the first casing body and the second casing body, which are divided by a plane including the main shaft, via a joint surface,
A pump provided with a shaft sealing portion for sealing between the main shaft and the casing in the shaft through hole,
A pump characterized in that a sealing passage for supplying liquid in the discharge side chamber to the shaft sealing portion and liquid-sealing the shaft sealing portion is formed in the wall thickness of the casing. The sealing liquid passage has at least a groove-shaped first supply passage formed on the joint surface of the first casing body,
2. The pump according to claim 1, wherein the first supply passage is provided inside the thickness of the casing in a state where the first casing body and the second casing body are joined. The pump according to claim 2, wherein the first supply passage has an upstream side communicating with the discharge side chamber and a downstream side communicating with the shaft seal portion. The sealing liquid passage has a second supply passage formed in the second casing body,
The second supply passage communicates with the discharge side chamber on the upstream side and with the first supply passage on the downstream side,
The pump according to claim 2, wherein the first supply passage communicates with the second supply passage on the upstream side and communicates with the shaft seal portion on the downstream side. In the first casing body, an escape passage branched from the first supply passage is formed,
The pump according to any one of claims 2 to 4, wherein a downstream side of the escape passage communicates with the suction side chamber. A relief passage is formed in the first casing body;
The downstream end of the second supply passage branches into a first supply passage and a relief passage;
The pump according to claim 4, wherein the downstream side of the escape passage communicates with the suction side chamber. The pressure reducing means for lowering the pressure of the shaft sealing liquid flowing from the discharge side chamber to the shaft sealing portion to a predetermined pressure is provided in the sealing liquid passage. The pump described in. 8. The pump according to claim 7, wherein the pressure reducing means is an orifice member fitted in the sealing passage. The pump according to any one of claims 1 to 8, wherein a foreign matter capturing member is provided in the sealing liquid passage. 10. The backwashing channel having one end opened in the end face of the casing and the other end communicating with the shaft seal portion is formed in the casing. 10. pump. It is a method of using the pump according to any one of claims 1 to 10,
When the sealing liquid passage is not used, a closing member is provided in the sealing liquid passage and the sealing liquid passage is sealed.

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