JPH1130337A - Shaft seal device for underwater machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain shaft seal function for a long period even it the shaft sealing liquid is a slurry containing fine particles in the water. SOLUTION: A ring shaped airtight liquid camber 21 is formed in a manner of encircling the outer circumference of a rotary motor 14 shaft 17 and the charging pressure of a lubricating liquid 22 such as grease changed inside the airtight liquid chamber 21 is set to the water pressure equaling to or higher than that in the area where an underwater machine 10 is installed. Thus water flowing into the rotary motor 14 along the contacting surface of the shaft 17 with the lubricating liquid 22 can be surely prevented and function to seal the rotary motor 14 shaft 17 can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shaft sealing device used for an underwater machine such as an underwater pump, an underwater stirrer, and an underwater excavator.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned underwater machine, an electric motor is usually used as a rotation source. In order to prevent water from entering the electric motor, a mechanical seal such as a shaft sealing device is provided on the rotating shaft. The oil seals are mounted in a state of being arranged in multiples.

Here, a mechanical seal is a device invented to completely prevent leakage of a shaft sealing portion of a rotating shaft.
A sliding ring attached to the shaft and a fixing ring that fits into the fixing portion contact the sliding surface to prevent leakage. The oil seal means a seal made of a seal material having a U-shaped cross section and having a spring inside which presses the seal surface of the seal material against the outer peripheral surface of the rotating shaft.

[0004]

However, the conventional shaft sealing device including the mechanical seal and the oil seal described above still has the following problems to be solved. That is,
In a shaft seal device consisting of a mechanical seal, when the fluid processed by the underwater machine is a slurry containing fine particles in water, fine particles enter between the sliding surfaces of the mechanical seal, and the sliding ring The underwater machine could not perform a stable operation underwater because the shaft seal was destroyed at an early stage due to wear. On the other hand, even in a shaft sealing device including an oil seal, when the fluid to be processed by the underwater machine is a slurry containing fine powder particles in water, the gap between the seal surface of the oil seal and the outer peripheral surface of the rotating shaft of the electric motor is reduced. The fine particles could enter into the sliding surface of, and the sealing surface would be worn and the shaft seal would be broken at an early stage, so that the underwater machine could not perform a stable operation in water.

The present invention has been made in view of such circumstances, and maintains the shaft sealing function for a long period of time even when the sealed liquid is a slurry containing fine powders and granules in water. An object of the present invention is to provide a shaft sealing device that can be used.

[0006]

According to the present invention, there is provided a semiconductor device comprising:
The shaft sealing device for a submersible machine according to the present invention is a shaft sealing device for a submersible machine attached to a rotary shaft of the rotary motor to prevent water from flowing into the rotary motor, wherein the outer peripheral surface of the rotary shaft is An annular liquid sealed chamber is formed in the surrounding state,
Lubricant liquid such as grease is sealed in the liquid sealed chamber,
The filling pressure of the lubricating liquid is set to be equal to or higher than the water pressure at the installation location of the underwater machine, and the contact surface between the lubricating liquid and the rotating shaft prevents water from flowing into the rotary motor. It is configured to prevent it.

According to a second aspect of the present invention, in the shaft sealing device for an underwater machine according to the first aspect, the liquid sealing chamber is provided on the outer peripheral surface of the rotary shaft along a plurality of axial directions. Provided. The shaft sealing device for an underwater machine according to claim 3,
2. The shaft sealing device for an underwater machine according to claim 1, wherein a mechanical seal is arranged on the outer peripheral surface of the rotating shaft along the liquid sealed chamber.

According to a fourth aspect of the present invention, there is provided a shaft sealing device for an underwater machine according to any one of the first to third aspects, wherein the lubricating liquid is sealed in the liquid sealed chamber. And a relief valve for setting the sealing pressure of the sealed lubricating liquid to a predetermined pressure. The shaft sealing device for a submersible machine according to claim 5 is as follows.
4. The shaft sealing device for an underwater machine according to any one of claims 1 to 3, further comprising an accumulator for filling the lubricating liquid at a predetermined pressure in the vicinity of the underwater machine, wherein the accumulator communicates with the liquid sealed chamber. Are linked.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, with reference to the attached drawings, several embodiments embodying the present invention will be described for the understanding of the present invention.

(First Embodiment) A configuration of a shaft sealing device A of a submersible machine according to the present embodiment will be described with reference to FIG. As shown in the drawing, the present embodiment is a case where a shaft sealing device A of a submersible machine is applied to a submersible agitator 10 which is an example of a submersible machine.

First, the structure of the underwater stirrer 10 will be described. The underwater stirrer 10 is attached to the supporting machine frame 12 while passing through the top plate 13 of the supporting machine frame 12 placed on the bottom surface 11 of the stirring water tank. Supported. That is, the underwater stirrer 10 is substantially a rotary motor 14 composed of an electric motor mounted vertically on the top plate 13 of the supporting machine frame 12,
A vertical cylindrical body 16 connected via a plurality of connecting ribs 15 radially arranged below the rotary motor 14 and a rotary shaft 17 extending downward from the center of the lower portion of the rotary motor 14 and fixed to a tip portion of the rotary shaft 17. And a stirring blade 18. An upper suction opening 19 is formed between the lower surface of the rotary motor 14 and the upper surface of the vertical cylinder 16 and the vertical cylinder 1
A lower discharge opening 20 is formed at the lower end of 6.

With this configuration, by driving the rotary motor 14 and rotating the stirring blade 18, the slurry and the like in the stirring water tank are sucked into the vertical cylinder 16 from the upper suction opening 19, and then the lower portion of the vertical cylinder 16 is rotated. By discharging the slurry into the agitated water tank through the lower discharge opening 20 provided in the agitator, a slurry (a mixture of fine particles such as bentonite in water) can be stirred and generated.

The underwater agitator 10 includes a rotary motor 14.
Is provided with a shaft sealing device A of an underwater machine for preventing water from flowing into the inside of the rotary motor 14. In the present invention, in the underwater agitator 10 having the above-described configuration, the shaft sealing device A of the underwater machine is formed into an annular liquid sealed chamber 21 so as to surround the outer peripheral surface of the rotating shaft 17. Is filled with a lubricating liquid 22 such as grease,
It is characterized in that the contact surface between the lubricating liquid 22 and the rotating shaft 17 prevents water from flowing into the rotating motor 14.

Hereinafter, the configuration of the shaft sealing device A of the underwater machine will be described in detail with reference to FIGS. As shown, the base of the rotating shaft 17 of the rotating motor 14 is
4 extends downward through a through hole provided at the center of the bottom wall 23, and a bearing 24 and a packing 25 are fitted and fixed in the through hole. As the packing 25, for example, an oil seal can be used.

As shown in FIG. 2, a cylindrical shaft sealing device mounting casing 26 is integrally and coaxially connected to the bottom wall 23 of the rotary motor 14. A cylindrical shaft sealing device main body 26 is provided in the lower wall opening 25a.
a is attached and fixed. Inside the shaft sealing device main body 26a, an upper through hole 27 having an outer diameter substantially equal to that of the rotating shaft 17 of the rotating motor 14 and an upper and lower oil seal 2 described later.
An enlarged lower through-hole 28 used to fit the 9, 30 is formed.

In the lower through hole 28, a pair of upper and lower oil seals 29, 30 are axially arranged with a spacer ring 29a.
The upper opening and the inner opening are opposed to each other, and the upper and lower oil seals 29 and 30, the inner peripheral wall of the lower through-hole 28, and the rotating shaft 17 are provided via an O-ring 17 b. The liquid sealed chamber 21 is defined and formed by the outer peripheral surface of the fitted shaft sleeve 17a. In addition, a retainer ring 31 is attached to a lower portion of the shaft sealing device main body 26a to hold the lower oil seal 30 at a predetermined position.

A concave portion 32 is formed on the outer peripheral surface of the shaft sealing device main body 26a corresponding to the central portion of the liquid sealed chamber 21. The concave portion 32 is an example of an injection port communicating with the inside of the liquid sealed chamber 21. An injection nipple 33 is mounted. The lubricating liquid 22 such as grease can be sealed in the liquid sealed chamber 21 at a predetermined pressure (for example, 0.8 kg / cm ² ) through the injection nipple 33. Here, the predetermined pressure is the water pressure at the place where the underwater stirrer 10 is installed,
More precisely, it is necessary to set the pressure higher than the slurry pressure above the stirring blade 18 when the underwater stirrer 10 is operated.

On the other hand, the lubricating liquid 22 in the liquid sealed chamber 21
Is set to the above-mentioned predetermined pressure, the outer peripheral surface of the shaft sealing device main body 26a corresponding to the central portion of the liquid sealed chamber 21 and the mounting point of the injection nipple 33 are set at 180 °.
A concave portion 34 is provided at the opposing portion.
Inside, a relief valve 35 communicating with the liquid sealed chamber 21 is provided. That is, when the sealing pressure of the lubricating liquid 22 in the liquid sealed chamber 21 exceeds a predetermined pressure (for example, 0.8 kg / cm ² ), the relief valve 35 operates to increase the pressure in the liquid sealed chamber 21. Is prevented, and the pressure in the liquid sealed chamber 21 can be set to the above-described predetermined pressure.

The reason why the predetermined pressure is set as described above is to prevent the slurry containing fine powders from entering the liquid sealed chamber 21 from the outside, and to set the sealing pressure excessively. This is to prevent the lubricating liquid 22 from excessively rising in temperature due to sliding friction heat generated by excessively pressing the seal lips of the lower oil seals 29 and 30 against the rotating shaft 17. After the predetermined pressure is set by the relief valve 35, the relief valve 35 is fixed and sealed by screwing a relief valve fixing plug 36 made of a blind plug into the recess 34.

Next, the underwater stirrer 1 having the above-described configuration will be described.
The operation of the shaft sealing device A of the underwater machine 0 and the underwater machine will be described with reference to FIGS. As described above, by the operation of the rotary motor 14, the stirring blade 18 rotates together with the rotating shaft 17, and the slurry in the stirring water tank is sucked into the vertical cylinder 16 from the upper suction opening 19, and then the lower portion of the vertical cylinder 16 is The liquid is discharged from the discharge opening 20 into the stirred water tank.

Here, when the slurry is a slurry containing fine particles in water, in the conventional shaft sealing device, the fine particles in the slurry enter together with the slurry between the sliding surfaces of the mechanical seal. As a result, the sliding ring may be worn and the shaft seal may be broken at an early stage. On the other hand, in the present embodiment, a predetermined pressure (for example, 0.8 k
g / cm ² ), a lubricating liquid 22 such as grease is sealed in the liquid sealed chamber 21, and the pressure is higher than the slurry pressure above the stirring blade 18 when the underwater stirrer 10 is operated. Since the setting is set, it is possible to reliably prevent the slurry containing the fine powder from entering the liquid sealed chamber 21 from the outside, and to achieve the sufficient shaft sealing function of the rotary motor 14. Become.

Further, a lubricating liquid 22 such as grease is used as a filling liquid sealed in the liquid sealed chamber 21.
Since the lubricating liquid 22 is pressurized, a lubricating film is formed on the sliding surfaces of the upper and lower oil seals 29 and 30 for a long time, wear can be prevented, and the shaft sealing function is maintained for a long time. Is done. Thereby, long-term stable operation of the underwater machine is achieved.

Since the liquid sealed chamber 21 is cooled by the external slurry and the diameter of the rotating shaft 17 is small, the rise in the pressure due to the rise in the temperature of the lubricating liquid 22 is limited to the upper and lower oil seals 29. , 30. Therefore, it is possible to reliably prevent the lower oil seals 20 and 30 from being damaged or leaked due to the increase in the pressure of the lubricating liquid 22.

(Second Embodiment) The configuration of a shaft sealing device A1 for a submersible machine according to the present embodiment will be described with reference to FIG. As shown in the drawing, the present embodiment has two liquid sealed chambers 40 having the same configuration as the liquid sealed chamber 21 in the shaft sealing device A of the underwater machine according to the first embodiment.
41 are mounted in the shaft sealing device main body 42 in series. That is, the liquid sealed chamber 40 is connected to the injection nipple 43 and the relief valve 44 so as to communicate with each other.
Is connected to the injection nipple 45 and the relief valve 46. In the liquid sealed chambers 40 and 41, a lubricating liquid 2 such as grease is applied at a pressure set higher than the slurry pressure above the stirring blade 18 when the underwater stirrer 10a is operated.
2 are enclosed.

With this configuration, it is possible to more reliably prevent the slurry containing fine powders and granules from flowing into the liquid sealed chambers 40 and 41 from the outside, and a sufficient shaft sealing function of the rotary motor 14 is achieved. Will be. In the present embodiment, the underwater stirrer 10 having substantially the same configuration as the underwater stirrer 10 in the first embodiment is used as the underwater machine.
Since a is used, each component of the underwater stirrer 10a is denoted by the same reference numeral.

(Third Embodiment) The configuration of a shaft sealing device A2 for a submersible machine according to the present embodiment will be described with reference to FIG. As shown in the figure, in the present embodiment, a liquid sealed chamber 50 having the same configuration as the liquid sealed chamber 21 in the shaft sealing device A of the underwater machine according to the first embodiment is mounted in the shaft sealing device main body 51. At the same time, between the bottom wall 23 of the rotary motor 14 and the shaft sealing device body 51, the mechanical seal 5
2 are mounted in series.

Here, the liquid sealed chamber 50 is provided with the injection nipple 5.
3 and a relief valve 54, and in the liquid sealed chamber 50, at a pressure set higher than the slurry pressure above the stirring blade 18 when the underwater stirrer 10b is operated, a lubricating liquid such as grease is used. 55 are enclosed. With such a configuration, the shaft of the rotary motor 14 can be double-sealed, and a perfect shaft sealing function of the rotary motor 14 is achieved. In this embodiment, since the underwater stirrer 10b having substantially the same configuration as the underwater stirrer 10 in the first embodiment is used as the underwater machine, each component of the underwater stirrer 10b is denoted by the same reference numeral. . In this embodiment, the use of the mechanical seal 52 eliminates the need for the packing 25 in the underwater agitator 10 according to the first embodiment.

(Fourth Embodiment) The configuration of a shaft sealing device A3 for a submersible machine according to the present embodiment will be described with reference to FIG. As shown in the figure, in the present embodiment, a liquid sealed chamber 60 having the same configuration as the liquid sealed chamber 21 in the shaft sealing device A of the underwater machine according to the first embodiment is It is characterized in that it is connected to an accumulator 62 attached to the lower side wall of the underwater stirrer 10c.

With this configuration, the accumulator 6
2, the lubricating liquid 63 can be filled at a predetermined pressure, and the lubricating liquid 63 in the liquid sealed chamber 60 is
The decrease in the sealing pressure due to the loss of the oil film between the upper and lower oil seals 29 and 30 and the rotary shaft 17 by a small amount is prevented by replenishing the lubricating liquid 63 from the accumulator 62 with a constant pressure. Therefore, the sealing pressure can be maintained at the predetermined pressure for a longer period of time. Therefore, it is possible to prevent the slurry containing the fine powder from entering the liquid sealed chamber 60 from the outside for a longer period of time, and the thorough shaft sealing function of the rotary motor 14 is achieved. In this embodiment, since the underwater stirrer 10c having substantially the same configuration as the underwater stirrer 10 in the first embodiment is used as the underwater machine,
Each component of the underwater stirrer 10c is denoted by the same reference numeral.

(Fifth Embodiment) The structure of a shaft sealing device A4 for a submersible machine according to the present embodiment will be described with reference to FIG. As shown in the figure, in the present embodiment, a shaft sealing device A4 of a submersible machine is connected to a submersible pump
0 is applied. First, the configuration of the submersible pump 70 will be described. An impeller casing 72 is mounted on a supporting machine frame 71 via a cylindrical strainer 71a.
A rotation motor 74 is connected via an intermediate cylinder 73.
An impeller 75 is rotatably disposed in the impeller casing 72. Also, the rotating shaft 7 of the rotating motor 74
Numeral 6 extends downward through the intermediate cylinder 73 and the impeller casing 72. An impeller 75 is fixed to the impeller casing 72, and a stirring blade 77 is attached to a lower extension end.

In this embodiment, in the submersible pump 70 having the above configuration, the shaft sealing device A4 of the submersible machine is
An annular liquid sealed chamber 81 is formed so as to surround the outer peripheral surface of the rotating shaft 76, a lubricating liquid 82 such as grease is sealed in the liquid sealed chamber 81, and contact between the lubricating liquid 82 and the rotating shaft 76 is made. The feature is that the surface is configured to prevent water from flowing into the inside of the rotary motor 74.

As shown in FIG. 6, the liquid sealed chamber 81 has substantially the same configuration as the liquid sealed chamber 21 according to the first embodiment. That is, the liquid sealed chamber 81 is connected to the injection nipple 83 and the relief valve 84 in communication. In the liquid sealed chamber 81, a lubricating liquid 8 such as grease is applied at a pressure set higher than the slurry pressure when the submersible pump 70 is operated.
2 are enclosed. With this configuration, it is possible to reliably prevent the slurry containing fine powders and granules from flowing into the liquid sealed chamber 81 from the outside, and also to achieve a sufficient shaft sealing function of the rotary motor 74 in the submersible pump 70. Will be.

As described above, the present invention has been described with reference to some embodiments. However, the present invention is not limited to the configurations described in the above-described embodiments, and claims are not limited thereto. This also includes other embodiments and modifications that can be considered within the scope of the described matters.

For example, in the above embodiment,
Both ends of the liquid sealed chamber are formed by one upper and lower oil seals, respectively, but can also be formed by arranging two or more upper and lower oil seals in an axially superposed state. In this case, the shaft sealing effect of the shaft sealing device can be further enhanced.

In the above embodiment, the accumulator is an internal pressure type accumulator in which the internal pressure of the lubricating liquid is set in advance and is not affected by the water pressure in the installation environment. It is also possible to use an external pressure type accumulator in which the liquid is sealed and the pressure in the liquid sealed chamber is equal to the water pressure under the influence of the water pressure in the installation environment.

[0036]

According to the shaft sealing device for an underwater machine according to the first aspect, an annular liquid sealed chamber is formed so as to surround the outer peripheral surface of the rotary motor, and a lubricating liquid such as grease is sealed in the liquid sealed chamber. Then, by setting the filling pressure of the lubricating liquid equal to or higher than the water pressure at the installation location of the submersible machine, the inflow of water into the rotary motor is prevented by the contact surface between the lubricating liquid and the rotating shaft. I try to prevent it. Therefore, it is possible to reliably prevent the slurry containing the fine particles from flowing from the outside into the liquid closed chamber,
The shaft sealing function of the rotary motor can be enhanced.

In particular, in the shaft sealing device for an underwater machine according to the second aspect, a plurality of liquid sealed chambers are provided along the axial direction on the outer peripheral surface of the rotating shaft. Therefore, it is possible to prevent the slurry containing the fine powder from outside from flowing into the liquid sealed chamber in two stages, and it is possible to further enhance the shaft sealing function of the rotary motor. In the shaft sealing device for a submersible machine according to the third aspect, a mechanical seal is juxtaposed on the outer peripheral surface of the rotating shaft along the liquid sealed chamber. Therefore, it is possible to prevent the slurry containing the fine powder from outside from flowing into the liquid sealed chamber in two stages, so that a sufficient shaft sealing function of the rotary motor can be maintained.

In the shaft sealing device for an underwater machine according to the present invention, the liquid sealing chamber is provided with an inlet for sealing a lubricating liquid, and a sealing pressure of the sealed lubricating liquid is maintained at a predetermined pressure. And a relief valve. Therefore,
The sealing pressure of the lubricating liquid in the liquid sealed chamber can be set to a predetermined pressure simply by sealing the lubricating liquid from the inlet, and the maintenance of the shaft sealing device of the underwater machine can be improved.

In the shaft sealing device for a submersible machine according to the present invention, an accumulator disposed near the submersible machine and filled with a lubricating liquid at a predetermined pressure is connected to the liquid sealed chamber. Therefore, the decrease in the sealing pressure due to the lubricating liquid in the liquid sealed chamber being lost little by little as an oil film between the oil seal and the rotating shaft is reduced by replenishing the lubricating liquid from the accumulator at a constant pressure. Since this can be prevented, the sealing pressure can be kept at the predetermined pressure for a longer period of time. Therefore, it is possible to prevent the slurry containing the fine particles from flowing into the liquid sealed chamber from the outside for a longer period of time, so that the shaft sealing function of the rotary motor is achieved.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an underwater stirrer provided with a shaft sealing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of the main part.

FIG. 3 is a front sectional view of an underwater stirrer provided with a shaft sealing device according to a second embodiment of the present invention.

FIG. 4 is a front sectional view of an underwater stirrer provided with a shaft sealing device according to a third embodiment of the present invention.

FIG. 5 is a front sectional view of an underwater stirrer provided with a shaft sealing device according to a fourth embodiment of the present invention.

FIG. 6 is a front sectional view of a submersible pump including a shaft sealing device according to a fifth embodiment of the present invention.

[Explanation of symbols]

A Shaft sealing device for underwater machine A1 Shaft sealing device for underwater machine A2 Shaft sealing device for underwater machine A3 Shaft sealing device for underwater machine A4 Shaft sealing device for underwater machine 10 Underwater agitator 10a Underwater agitator 10b Underwater agitator 10c Underwater agitator 11 Bottom 12 Supporting machine frame 13 Top plate 14 Rotary motor 15 Connecting rib 16 Vertical cylinder 17 Rotating shaft 17a Shaft sleeve 17b O-ring 18 Stirring blade 19 Upper suction opening 20 Lower discharge opening 21 Liquid sealed chamber 22 Lubricant liquid 23 Bottom wall 24 Bearing 25 Packing 25a Lower wall opening 26 Shaft sealing device mounting casing 26a Shaft sealing device main body 27 Upper through hole 28 Lower through hole 29 Upper oil seal 29a Spacer ring 30 Lower oil seal 31 Retainer ring 32 Recess 33 Injection nipple 34 Recess 35 Relief valve 36 Relief Valve fixing plug Reference Signs List 40 liquid sealing chamber 41 liquid sealing chamber 42 shaft sealing device main body 43 injection nipple 44 relief valve 45 injection nipple 46 relief valve 50 liquid sealing chamber 51 shaft sealing device main body 52 mechanical seal 53 injection nipple 54 relief valve 55 lubricating liquid 60 liquid sealing Chamber 61 Communication pipe 62 Accumulator 63 Lubricating liquid 70 Submersible pump 71 Supporting machine frame 71a Strainer 72 Impeller casing 73 Intermediate cylinder 74 Rotary motor 75 Impeller 76 Rotating shaft 77 Stirring blade 81 Liquid sealing chamber 82 Lubricating liquid 83 Injection nipple 84 Relief valve

Claims (5)

[Claims] 1. A shaft sealing device for an underwater machine attached to a rotating shaft of a rotary motor for preventing water from flowing into the rotary motor, the ring sealing device surrounding an outer peripheral surface of the rotary shaft. A liquid sealed chamber is formed, and a lubricating liquid such as grease is sealed in the liquid sealed chamber, and the sealing pressure of the lubricating liquid is set to be equal to or higher than the water pressure at the installation location of the underwater machine, A shaft sealing device for a submersible machine, wherein the lubricating liquid and a contact surface of the rotating shaft prevent water from flowing into the rotating motor. 2. The shaft sealing device for an underwater machine according to claim 1, wherein a plurality of the liquid sealing chambers are provided on an outer peripheral surface of the rotary shaft along an axial direction. 3. The shaft sealing device for an underwater machine according to claim 1, wherein a mechanical seal is provided in parallel with the outer peripheral surface of the rotating shaft along the liquid sealed chamber. 4. An inlet for sealing the lubricating liquid in the liquid sealed chamber and a relief valve for setting a sealing pressure of the sealed lubricating liquid to a predetermined pressure are provided. The shaft sealing device for a submersible machine according to any one of claims 1 to 3, characterized in that: 5. An accumulator that fills the lubricating liquid at a predetermined pressure near the underwater machine, and the accumulator is connected to the liquid sealed chamber. The shaft sealing device for a submersible machine according to any one of the preceding claims.