JP4263789B2 - pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pump in which a shaft of a motor unit connected to an impeller is shaft-sealed by a mechanical seal and a shaft sealing chamber in which lubricating oil is stored.
[0002]
[Prior art]
For drainage of water such as miscellaneous wastewater, building wastewater, and pool water, a drainage submersible pump having a high hermeticity that does not have the risk of water entering from the outside is used.
[0003]
In such a drainage pump, a vortex-structured pump unit, an impeller with one side open, an impeller with both sides closed, and an S-shaped impeller are arranged on a motor unit that is arranged vertically with the motor shaft facing downward. A structure combining the adopted pump and the like is adopted. Specifically, the pump portion employs a structure in which the tip portion of the motor shaft extending downward passes through the casing cover and is connected to the casing cover and the impeller housed in the casing. Is transmitted to the impeller, and the impeller is rotated to suck the waste water from the suction port formed in the casing and discharge it from the discharge port similarly formed in the casing.
[0004]
Such a drainage water pump is required to be sealed while lubricating between the motor shaft and the casing cover, particularly under sealed conditions.
[0005]
For this reason, a shaft seal structure is employed for the seal of the shaft portion penetrating the casing cover.
[0006]
In this shaft seal structure, as shown in FIG. 5, a mechanical seal c is wound around the outer peripheral surface of the motor shaft b penetrating the casing cover a, and the seal c is attached to the end wall e of the motor part d and the casing cover. and a recess is formed in the casing cover portion around the mechanical seal c, and a shaft seal chamber f is formed from a space surrounded by the recess and the end wall e. The shaft seal chamber f A structure in which the lubricating oil g is accommodated is employed. The mechanical seal c is always immersed in the lubricating oil g (oil), and the contact surface between the motor shaft b and the mechanical seal c is sealed with the lubricating oil g. In FIG. 5, h is a casing, i is an impeller, j is a suction port, and k is a discharge hole.
[0007]
[Problems to be solved by the invention]
By the way, in the shaft seal structure, the air above the oil level in the shaft seal chamber f is replaced with the pressure water in the casing covers / casings a and h through the mechanical seal c due to the influence of secular change, etc., and gradually decreases. There are things to do. As this replacement proceeds, the amount of liquid in the shaft seal chamber f increases.
[0008]
However, the shaft sealing chamber f occupies about 80% of the space of the shaft sealing chamber f so that the mechanical seal c is always immersed in the lubricating oil g regardless of whether the pump is installed horizontally or vertically. Thus, the lubricating oil g is sealed, and the air portion of the shaft sealing chamber f, that is, the air layer portion above the oil surface is small.
[0009]
For this reason, the shaft sealing chamber f may be filled due to the influence of pressure water entering from the mechanical seal c, and the liquid in the coaxial sealing chamber f may reach the motor part d immediately above the shaft sealing chamber f. In such a case, the liquid enters the bearing part m of the motor part d and each part of the motor.
[0010]
The drainage submersible pump causes a failure due to rusting of the bearing part m of the motor part d, insulation failure or insulation deterioration of the motor part d, and the replacement of the pump is required. It was sometimes done.
[0011]
Therefore, it is conceivable to increase the volume by increasing the height dimension of the shaft seal chamber f, and to increase the air portion above the oil level while maintaining the amount of lubricating oil.
[0012]
However, since the ratio of the lubricating oil f occupying the space of the shaft sealing chamber f is reduced, the contact surface of the mechanical seal c is not immersed in the lubricating oil f when the pump is installed sideways, so that the shaft sealing function cannot be maintained. It cannot be easily dealt with.
[0013]
The present invention has been made paying attention to the above circumstances, and an object of the present invention is to provide a pump capable of extending the life of the pump while maintaining good shaft sealing performance.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an air chamber communicating with the shaft sealing chamber is formed between the motor portion and the shaft sealing chamber constituting the shaft sealing portion for shaft sealing the shaft of the motor portion, and enters from the mechanical seal. When the shaft seal chamber is filled with pressurized water, the air chamber is subsequently filled.
[0015]
According to this pump, due to aging, etc., the air in the shaft seal chamber is replaced with pressure water and decreases, and the entire shaft seal chamber is filled with liquid, and when the capacity of the shaft seal chamber is exceeded, the same capacity is exceeded. Minutes are stored in the air chamber.
[0016]
Thereby, the time when the mixed water of the lubricating oil and the pressure water reaches the motor portion is delayed by the capacity of the air chamber, and the life of the pump can be extended. In addition, since the shaft sealing chamber may be left as it is, a good shaft sealing function is maintained.
[0017]
Furthermore, in addition to the above-mentioned purpose, an air chamber is formed by using a part of the shaft seal chamber by interposing a partition wall member at the boundary between the motor unit and the shaft seal chamber so that the air chamber can be easily formed. The structure is as follows.
[0018]
Furthermore, in addition to the above purpose, the partition member can be attached to and detached from the motor part and the casing cover so as to secure an air chamber and a shaft seal chamber with an appropriate capacity according to the type and operating conditions of the pump. The partition wall is made up of multiple types of brackets with different numbers of irregularities, and the air chamber capacity can be changed by selecting the bracket. An air chamber and a shaft seal chamber were formed.
[0019]
In another embodiment, the partition member is interposed between the outer peripheral part of the end wall of the motor part and the outer peripheral part of the casing cover facing the motor part so that an air chamber can be easily formed using an existing structure. A peripheral wall portion, a partition wall formed so as to block between the peripheral wall portions, a holding portion formed in the partition wall for holding a mechanical seal, and a through hole formed in the partition wall through which the shaft passes. The lower wall side of the partition wall is combined with the casing cover so as to form the ceiling of the shaft seal chamber, the upper surface side of the partition wall is combined with the end wall of the motor unit to form an air chamber, and the clearance between the through hole and the shaft is the shaft seal chamber And a passage that communicates between the air chamber and the air chamber.
[0020]
Further, in order to reduce the frequency at which the mixed water of lubricating oil and pressure water does not easily enter the motor unit, and the motor unit further fails, the shaft from the air chamber extends to the base side of the shaft extending from the motor unit. A sealing member for preventing liquid from entering was attached.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on an embodiment shown in FIGS.
[0022]
FIG. 1 shows a pump to which the present invention is applied, for example, a drain water pump, in which 1 is a motor unit and 2 is a vortex type pump unit, for example.
[0023]
The motor unit 1 is composed of an electric motor arranged so that a motor shaft 1a (corresponding to the shaft of the present application) protruding from the motor unit 1 faces downward.
[0024]
The casing structure of the pump unit 2 is configured by assembling a horizontally extending casing 5 disposed on the lower side and a circular casing cover 6 closing the impeller carry-in port 5 a disposed on the upper side. An impeller chamber 7 is formed on the right side portion surrounded, and a pressure feed path 8 is also formed on the left side portion. A suction port 9 is formed in the casing portion that is the central portion of the impeller chamber 7, and a discharge port 10 is formed in the upper right portion of the casing 5 that is the end of the pressure feed path 8. An impeller 11 is housed in the impeller chamber 7. An annular rib 12 for holding a mechanical seal is formed on the upper portion of the casing cover 6 at the center of the impeller chamber 7. Further, the casing cover portion around the rib 12 is recessed in an annular shape. However, 14 shows the leg part for vertical installation protruded from the outer peripheral side of the lower surface of the casing 5.
[0025]
The motor unit 1 and the casing cover 6 are separated from each other. A bracket 15 (corresponding to the partition wall member of the present application) is attached so as to be able to compensate for this gap.
[0026]
As shown in FIG. 3, the bracket 15 is a wall portion interposed between the outer peripheral portion of the end wall of the motor unit 1 and the outer peripheral portion of the casing cover 6 facing this, for example, a peripheral wall having a double cylindrical shape. A partition wall 18 formed at the upper end of the peripheral wall portion 17 is formed so as to shield the portion 17 from the peripheral wall portion 17. Further, an annular fitting recess 17 a that fits with an annular fitting protrusion 1 d formed on the outer peripheral portion of the end wall of the motor portion 1 is formed at the upper end portion of the peripheral wall portion 17. An annular fitting protrusion 17 b that fits with an annular fitting recess 6 c formed on the outer periphery of the casing cover 6 is formed at the lower end of the peripheral wall portion 17. The entire bracket 17 is attached to and detached from the outer peripheral portion of the end wall of the motor portion 1 and the outer peripheral portion of the casing cover 6 with a bolt 20 using a cylindrical boss portion 19 formed between the double walls. It is connected as possible.
[0027]
A through hole 21 is formed at the center of the partition wall 18, and the motor shaft 1 a passes through the through hole 21. The tip of the motor shaft 1 a is connected to the impeller 11 through a through hole 6 a formed in the cylindrical mechanical seal 23 and the casing cover 6. Accordingly, the driving force of the motor unit 1 is transmitted to the impeller 11, so that wastewater such as sewage is sucked from the suction port 9 by the rotating impeller 11 and is discharged from the discharge port 10 through the pressure feed path 8. It is.
[0028]
An annular rib 22 for holding a mechanical seal is formed on the lower surface of the partition wall around the through hole 21. Between the rib 22 and the rib 12 of the casing cover 6, a mechanical seal 23 fitted on the outer peripheral surface of the motor shaft 1 a is held.
[0029]
Then, the lower surface side of the partition wall 18 is combined so as to close the recessed portion 6 a of the casing cover 6, and the shaft sealing chamber 13 is formed around the mechanical seal 23 where the lower surface portion of the partition wall 18 forms a ceiling. Lubricating oil 24 (oil) is sealed in the shaft sealing chamber 13. The lubricating oil 24 is sealed so as to occupy about 80% of the internal space of the shaft seal chamber 13, and the mechanical seal 23 is always used as the lubricating oil 24 regardless of whether the pump is installed horizontally or vertically. The shaft seal part of the structure to be immersed is comprised. That is, in any pump installation, the motor shaft 1a is sealed while being lubricated.
[0030]
Further, the upper surface side of the partition wall 18 is combined with the end wall 1b of the motor unit 1 and is flattened directly above the shaft sealing chamber 13 in cooperation with the recess 1c already formed in the end wall 1b for forming the shaft sealing chamber. An air chamber 25 is formed in the shape of a space.
[0031]
The air chamber 25 and the shaft sealing chamber 13 communicate with each other through a passage 26 formed by a gap between the through hole 21 and the motor shaft 1 a passing through the through hole 21. As a result, when the entire shaft seal chamber 13 is filled with the pressure water that enters from the mechanical seal 23, the same liquid is then accommodated in the air chamber 25 through the passage 26.
[0032]
Further, as shown in FIG. 3, the partition wall 18 is formed with a plurality of convex portions 18a formed by bending a part of the partition wall 18, for example, radially at a predetermined interval. And the shaft sealing chamber 13 and the air chamber 25 having a capacity suitable for the pump are obtained by using the uneven portion of the partition wall 18.
[0033]
That is, as for the bracket 15, for example, a plurality of types of brackets 15a to 15c having different numbers of the convex portions 18b are prepared. Specifically, as shown in FIG. 4 (a), a bracket 15a having no convex portion 18, a bracket 15b having a convex portion 18b as shown in FIG. A bracket 15c is prepared in which the number of convex portions 18b as shown in FIG. 4 (c) is halved. By replacing the bracket 15, a large-capacity air chamber 25 (small-capacity shaft seal chamber 13), A small-capacity air chamber 25 (large-capacity shaft sealing chamber 13), an intermediate-capacity air chamber 25 (medium-capacity shaft sealing chamber 13), and the like can be formed.
[0034]
Further, a motor shaft portion (corresponding to the base side of the shaft of the present application) that is the front side of the bearing portion 1e of the motor portion 1a, for example, a through-hole portion of the end wall 1b through which the motor shaft 1a passes is formed of an elastic body such as rubber. In addition, a sealing member 27 having an annular lip 27a that prevents liquid from entering, for example, is incorporated, and the gap between the through hole portion and the motor shaft portion is sealed, so that liquid cannot easily enter the air chamber 25. It is
[0035]
In FIG. 1, reference numeral 29 denotes a lubricating oil filling port formed in the casing cover 6, and 30 denotes a plug that closes the opening 29.
[0036]
Next, the operation of the drainage submersible pump configured as described above will be described. For example, in order to pump up sewage, for example, a drainage submersible pump is installed vertically in a place where sewage collects, and the motor unit 1 is operated from this state. To do.
[0037]
Then, sewage (drainage) is sucked from the suction port 9 by the rotating impeller 11. Then, the sewage is discharged from the discharge port 10 to the pumping pipe 28 connected to the discharge port 10 through the pressure feed path 8.
[0038]
At this time, the shaft portion that penetrates the casing cover 6 is sealed by the mechanical seal 23 using the lubricating oil 24.
[0039]
Such an operation is repeated, and for example, aging occurs, and the air on the oil level of the shaft seal chamber 13 is gradually reduced by replacing the pressure water in the casing / casing cover 5, 6 through the mechanical seal 23. To do.
[0040]
At this time, it is assumed that the oil amount level in the shaft seal chamber 13 is increased by the replacement as shown by the arrow in FIG. 1 and the entire shaft seal chamber 13 is filled with the lubricating oil 24 and the pressure water.
[0041]
Thereafter, the replaced liquid is introduced into the air chamber 25 formed immediately above the shaft seal chamber 13 through the passage 26 and is accommodated in the air chamber 25.
[0042]
That is, the amount exceeding the capacity of the shaft seal chamber 13 is stored in the air chamber 25.
[0043]
This can delay the time when the mixed water of the lubricating oil 24 and the pressure water reaches the motor unit 1 by the capacity of the air chamber 25.
[0044]
Therefore, the frequency of occurrence of failure due to the mixed water entering each part of the motor unit 1 can be reduced. In addition, since the shaft seal chamber 13 may have the same shape and oil amount, the frequency of failure of the motor unit 1 can be suppressed while ensuring a good shaft seal function, and the life of the drainage submersible pump can be extended. . In particular, by incorporating the sealing material 27 that suppresses the ingress of liquid from the air chamber 25 on the base side of the motor shaft 1a, the mixed water of the lubricating oil 24 and the pressure water is more difficult to enter the motor unit 1. Furthermore, the frequency of occurrence of failure of the motor unit 1 is further reduced, and the life of the drainage pump can be further extended.
[0045]
In addition, since the air chamber 25 is formed by interposing a bracket 15 at the boundary between the motor unit 1 and the shaft seal chamber 13 and also using a part of the existing shaft seal chamber 13, the air chamber can be easily formed. 25 can be formed. In particular, the bracket 15 forms a shaft seal chamber 13 by combining the lower surface side with the casing cover 6, and forms an air chamber 25 by combining the upper surface side with the end wall 1 b of the motor unit 1, and a through hole 21 through which the motor shaft 1 a passes. However, since the passage 26 is formed between the shaft seal chamber 13 and the air chamber 25, the air chamber 25 can be easily formed using the existing structure.
[0046]
In addition, since a plurality of types of brackets 15 are prepared for each capacity, the shaft seal chamber 13 and the air chamber 25 having appropriate capacities can be obtained by properly using the brackets 15 according to the type and usage conditions of the pump. It can be secured. For example, when the air chamber 25 having a large capacity (the shaft seal chamber 13 having a small capacity) is required, the bracket 15a having no convex portion 18a shown in FIG. 4A is selected, and this is shown in FIG. It is sufficient to interpose between the motor unit 1 and the shaft sealing chamber 13. When the air chamber 25 with a small capacity (the shaft seal chamber 13 with a large capacity) is required, the bracket 15b having a plurality of convex portions 18a shown in FIG. What is necessary is just to interpose between the motor part 1 and the shaft sealing chamber 13 so that it may be shown. When the medium capacity air chamber 25 (medium capacity shaft seal chamber 13) is required, the bracket 15c in which the number of the protrusions 18a shown in FIG. 1 and the shaft seal chamber 13 may be interposed.
[0047]
In one embodiment, the capacity of the air chamber (shaft seal chamber) can be varied by using a structure in which a convex portion is formed on the partition wall of the bracket. It is good also as a structure which can vary the capacity | capacitance of an air chamber (shaft sealing chamber) by forming in a partition wall.
[0048]
Moreover, in one embodiment, although this invention was applied to the drainage water pump, this invention may be applied not only to this but the pump which employ | adopts another shaft seal structure.
[0049]
【The invention's effect】
As described above, according to the invention described in claim 1, without changing the shaft seal function of the shaft seal portion, it is possible to delay the time when the mixed water of the lubricating oil and the pressure water reaches the motor portion, It is possible to suppress the frequency of failure of the motor unit due to the mixed water entering.
[0050]
Therefore, it is possible to extend the life of the pump while maintaining good shaft sealing performance.
[0051]
According to invention of Claim 2, in addition to the said effect, an air chamber can be formed easily.
[0052]
According to the third aspect of the present invention, in addition to the above effects, an air chamber can be easily formed using an existing structure.
[0053]
According to the invention of claim 4, in addition to the above effect, the mixed water is more difficult to enter the motor unit, so that the frequency of the motor unit failure is further reduced and the pump life is further extended. Can be planned.
[0054]
According to the fifth aspect of the present invention, in addition to the above effect, an air chamber (shaft seal chamber) having an appropriate capacity can be easily obtained according to the type and operating conditions of the pump simply by replacing the partition member. Can be secured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a shaft seal structure of a pump according to an embodiment of the present invention together with a large-capacity air chamber.
FIG. 2 is a cross-sectional view showing a case where a small-capacity air chamber is formed.
FIG. 3 is a perspective view, partly in section, of a bracket that forms the air chamber.
FIG. 4 is a cross-sectional view for explaining the structure of a bracket for each capacity.
FIG. 5 is a cross-sectional view for explaining a shaft seal structure used in a conventional drainage pump.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Motor part 1a ... Motor shaft (shaft)
DESCRIPTION OF SYMBOLS 1b ... End wall 5 ... Casing 6 ... Casing cover 11 ... Impeller 13 ... Shaft sealing chamber 15, 15a-15c ... Bracket (partition wall member)
17 ... peripheral wall 18 ... partition wall 20 ... bolt 21 ... through hole 23 ... mechanical seal 24 ... lubricating oil 25 ... air chamber 26 ... passage 27 ... sealing material (seal member).

Claims (3)

It has a shaft extending downward from the motor portion, the tip of this shaft passes through the casing cover and is connected to the impeller, and the shaft portion passing through the casing cover is the same as the mechanical seal incorporated in the casing cover. A pump sealed around a shaft seal chamber formed around the mechanical seal and dipping the mechanical seal with lubricating oil;
Between the motor part and the shaft seal chamber, an air chamber communicating with the shaft seal chamber is formed,
The air chamber is configured to be subsequently filled when the shaft seal chamber is filled with pressure water entering from the mechanical seal ,
The air chamber is formed by combining a part of the shaft sealing chamber by interposing a partition member at a boundary between the motor unit and the shaft sealing chamber,
The partition member is composed of a plurality of types of brackets that are detachable between the motor unit and the casing cover, and in which a plurality of uneven portions having different quantities are formed on the partition wall unit. The pump is characterized in that the capacity of the air chamber is made variable. The partition member includes a peripheral wall portion interposed between an outer peripheral portion of the end wall of the motor portion and an outer peripheral portion of the casing cover facing the motor, a partition wall formed so as to block between the peripheral wall portions, A holding portion that is formed in the partition wall and holds the mechanical seal; and a through hole that is formed in the partition wall and through which the shaft passes,
The lower surface side of the partition wall is combined with the casing cover so as to form the ceiling of the shaft sealing chamber, the upper surface side of the partition wall is combined with the end wall of the motor unit to form the air chamber, and the through hole and the shaft The pump according to claim 1, wherein a gap between the shaft sealing chamber and the air chamber forms a passage communicating with the shaft sealing chamber. 3. The pump according to claim 1, wherein a seal member that prevents liquid from entering from the air chamber is attached to a base side of a shaft extending from the motor unit. 4.

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