JP2004257529A - Mechanical seal device - Google Patents

Abstract

A simple structure prevents leakage of pump liquid, and even if the pump liquid leaks and the leak liquid is corrosive or has a slurry content, a bearing device, etc. Provided is a mechanical seal device capable of surely preventing corrosion damage of a member.
A rotary shaft is rotatably sealed by a double-type mechanical seal housed in a seal housing provided on a rear side of a pump casing, and the housing is loaded with the seal housing. It is rotatably supported by the bearings 30A, 30B, 30C of the bearing box 4 constituting the bearing device 34 via the chamber 33. Further, a pressure accumulating tank 37 formed of an accumulator is installed outside the bearing box 4, and the lubricating / shaft sealing liquid is supplied from the accumulating tank 37 to the seal housing 32 via the lubricating / shaft sealing liquid supply pipe 38.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mechanical seal device.
[0002]
[Prior art]
Conventionally, for example, as a standard method of cooling a sliding portion in a mechanical seal for sealing a rotary main shaft of a pump, a method of guiding flushing water from an external water source to seal the water, and a method of flushing self-pumping water of the pump. A technique for sealing water as water is known. However, the former method of guiding the flushing water from an external water source and sealing the water has disadvantages such as not only increasing the cost of water introduction equipment but also complicating maintenance for maintenance. Also, the latter method of sealing the self-pumping water as flushing water has a drawback that if the pump's self-pumping water has a slurry component, it damages the pump bearing and makes it impossible to continue the operation of the pump. I have.
[0003]
Therefore, a mechanical seal device has been proposed in which the use of flushing water as in the former and the latter is avoided and the lubricating oil for the pump bearing can be shared as the lubricating oil for the mechanical seal.
[0004]
First, as shown in FIG. 3, an impeller (impeller) 3 housed in a pump casing 2 is attached to the tip of a rotary shaft 1 of the pump, and has a function of a cylinder between the pump casing 2 and the bearing box 4. A fluid storage unit 6 is formed by installing an outer cylinder 5, and a fluid pressurizing device 7 formed by a screw pump is formed at a substantially central portion between the pump casing 2 of the rotating shaft 1 and the bearing box 4. The outer peripheral surface of the piston 8 acting as a case of 7 is slidably and liquid-tightly contacted with the inner peripheral surface of the outer cylinder 5 to form a pressure fluid passage 10 including a check valve 9 in the piston 8, A pressure adjusting groove 11 is provided on the inner peripheral surface of the outer cylinder 5 for pressure adjustment, and a mechanical seal 13 is provided on the rotary shaft 1 immediately after the mounting position of the impeller 3 and the through hole 12 on the rear wall of the pump casing 2. And mechanical A space surrounded by the bearing 13, the front surface of the piston 8, and the inner surface of the cylinder 5 is defined as a high-pressure fluid chamber 14, and a pressure spring 15 is interposed between the front surface of the bearing box 4 and the rear surface of the piston 8. A space surrounded by the front surface of the box 4, the rear surface of the piston 8, and the inner surface of the cylinder 5 is defined as a fluid storage portion 6. The fluid storage portion 6 lubricates the sliding surface of the mechanical seal 13 and slides with its viscosity. There is a mechanical seal device filled with a lubricating / shaft sealing liquid (lubricating oil) capable of preventing liquid leakage from a moving surface and exhibiting a cooling effect (for example, see Patent Document 1).
[0005]
On the other hand, as shown in FIG. 4, a fluid pressurizing device 7 composed of a screw pump is provided at a portion of the rotating shaft 1 located in the bearing box 4, and an inner periphery of a piston 8 that operates corresponding to the fluid pressurizing device 7. The surface is spaced from the outer peripheral surface of the fluid pressurizing device 7 at an appropriate distance, and the outer peripheral surface is slidably and liquid-tightly contacted with the inner peripheral surface of the bearing box 4 functioning as the outer cylinder 5. A pressure spring 15 is provided at the rear of the piston 8 to urge the piston 8, and the rear side of the piston 8 forms a low-pressure chamber 17 and the front side forms a high-pressure chamber 18. A contact portion 19 is provided at a position corresponding to the position, and two communication paths 21 and 22 are provided between the tank 20 installed outside the outer cylinder 5 and the outer cylinder 5, and one of the communication paths 21 and 22 is provided in the low-pressure chamber 17. The other one communicates where the piston 8 is located In both cases, when the piston 8 is pressed by the high-pressure fluid, the fluid transferred from the fluid passage 23 provided on the outer peripheral portion of the piston 8, the pressure adjusting groove 24, and the fluid relief groove 25 provided on the outer cylinder 5 is connected to the fluid. The through-holes 27A and 27B are formed in the front wall 26 of the bearing box 4 functioning as the outer casing 5 so as to be transferred into the tank 20 through the passage 22. The through hole 27A is located at a position corresponding to the opening of the fluid passage 29 having the valve 28, and the lubrication / shaft sealing liquid (lubricating oil) of the mechanical seal 13 is supplied to the tank 20, the low-pressure chamber 17 and the high-pressure chamber 18. There is a mechanical seal device that is filled (for example, see Patent Document 2).
[0006]
In the conventional mechanical seal device described with reference to FIGS. 3 and 4, lubricating oil for the bearings 30, 30A, 30B, and 30C is supplied when the rotating shaft 1 and the impeller (impeller) 3 rotate, that is, the shafts such as pumps are rotated. At the time of operation of the sealing device, the fluid is continuously supplied to the mechanical seal 13 by the pressurization of the fluid pressurizing device 7 composed of a screw pump. Is applied to the mechanical seal 13 via the piston 8 by the spring force of.
[0007]
[Patent Document 1]
JP-A-58-113660, FIG. 2 [Patent Document 2]
JP-A-59-119098, sectional view of the embodiment
[Problems to be solved by the invention]
[0009]
Incidentally, since the pressure of the lubricating oil is usually higher than the pressure of the pumping liquid, the lubricating oil leaks to the pump side in the mechanical seal 13 and mixes with the pumping liquid. However, if the lubricating oil runs short due to leakage to the pump side and the pressure of the lubricating oil drops, or if the pressure of the pumping liquid increases during a shutoff operation of the pump, the pumping liquid flows to the lubricating oil side. As a result, the pump pumping liquid may be mixed into the lubricating oil due to the pumping liquid being mixed into the lubricating oil or the roughening of the sliding portion of the mechanical seal 13. As described above, even if the pumping liquid is mixed into the lubricating oil, there is no significant problem if the pumping liquid is non-corrosive or has no slurry. However, if the corrosive pumping liquid mixes with the lubricating oil, it leads to a serious problem that the rotating shaft 1 and the bearings 30, 30A, 30B, 30C, etc., which are not made of the corrosion-resistant material, are damaged, and the pump having a slurry portion is damaged. If the pumped liquid mixes with the lubricating oil, it damages the bearings 30, 30A, 30B, 30C, etc., and leads to a serious problem that makes it impossible to continue the operation of the pump. In addition, the fluid pressurizing device 7 including a screw pump, the pressurizing spring 15, the pressure fluid passage 10 including the check valve 9, the fluid passage 29 including the check valve 28, and the like are required. Have.
[0010]
The present invention has been made in view of such circumstances, and with a simple structure, prevents leakage of the pump liquid, and in the unlikely event that the pump liquid leaks, the liquid is corrosive. It is an object of the present invention to provide a mechanical seal device capable of reliably preventing corrosion damage of a bearing device and the like even if the material has a slurry content.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a mechanical seal device according to the present invention includes a mechanical seal that seals a rotating shaft of a shaft-sealed device, a seal housing in which the mechanical seal is loaded, and a lubrication / shaft in the seal housing. A pressure storage tank for supplying a sealed liquid, wherein the rotating shaft is rotatably supported by a bearing device via a housing charging chamber in which the seal housing is mounted.
[0012]
According to the present invention, lubrication / shaft sealing liquid (lubricating oil) can be supplied to the seal housing, in which the mechanical seal is inserted, by the pressure accumulating tank at a pressure corresponding to the pressure of the pumping liquid to seal the shaft. it can. Also, even if the pumped liquid leaks from the seal housing, the leaked pumped liquid is received by the housing charging chamber, and thus does not affect the bearing device. Therefore, even if a corrosive pumping liquid or a pumping liquid containing a slurry leaks, it is possible to reliably prevent corrosion damage to the bearing device and the like.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a right side view of FIG. The same or corresponding parts as those in the conventional example shown in FIGS. 3 and 4 are denoted by the same reference numerals and described.
1 and 2, an impeller (impeller) 3 housed in a pump casing 2 is attached to the tip of a rotary shaft 1 of the pump, and the rotary shaft 1 is attached to a seal housing 32 provided on the rear side of the pump casing 2. The shaft is rotatably sealed by a mechanical seal 13 housed therein. The mechanical seal 13 includes a mechanical seal 13A at a front stage on a pump casing side and a mechanical seal 13B at a rear stage on a bearing box 4 side. And a double-shaped mechanical seal 13 having a sliding portion. Further, it is rotatably supported by bearings 30A, 30B, 30C of a bearing box 4 constituting a bearing device 34 via a housing loading chamber 33 in which a seal housing 32 is loaded.
[0014]
A pressure storage tank 37 formed of, for example, an accumulator is provided outside the bearing box 4 via support rods 35 and a support plate 36, and the pressure storage tank 37 is connected to the pressure storage tank 37 through a lubrication / shaft sealing liquid supply pipe 38. To supply the lubrication / shaft sealing liquid to the seal housing 32 to lubricate the sliding surfaces of the mechanical seal 13A and the mechanical seal 13B at the preceding stage of the mechanical seal 13, prevent the leakage from the sliding surface with viscousness, and It is configured so that it can exert a cooling action. A drain hole 39 is provided at the bottom of the housing charging chamber 33, and an oil hole 40A and an oil drain hole 40B are provided in the bearing box 4 for lubricating oil for lubricating the bearings 30A, 30B, and 30C. It is. In the drawing, reference numeral 41 denotes a valve, which is provided in the lubrication / shaft sealing liquid supply pipe 38. Reference numeral 42 denotes a V-ring, which is covered with a seal retainer attached to the front end of the bearing box 4 to prevent the lubricating oil circulating in the bearing box 4 from leaking into the housing charging chamber 33.
[0015]
With such a configuration, lubrication / shaft sealing liquid (lubricating oil) can be supplied to the seal housing 32 in which the mechanical seal 13 is loaded, for example, by the accumulator tank 37 formed of an accumulator to seal the shaft. it can. Moreover, even if the pumped liquid leaks from the seal housing 32, the leaked pumped liquid is received at the housing loading chamber 33 in which the seal housing 32 is loaded, and is provided at the bottom thereof. Since the liquid can be discharged from the drain hole 39 and collected as appropriate, the bearings 30A, 30B, and 30C of the bearing device 34 are not affected. Therefore, even if the corrosive pumping liquid leaks, the rotating shaft 1 and the bearings 30, 30A, 30B, 30C, etc., which are not made of the corrosion-resistant material, are not damaged. Also, even if a pumping liquid containing a slurry leaks, the bearings 30, 30A, 30B, 30C are not damaged, so that the proper operation of the pump can be continued. In addition, the fluid pressurizing device 7 including a screw pump, the pressurizing spring 15, the pressure fluid passage 10 including the check valve 9, and the fluid passage including the check valve 28 required in the conventional example described with reference to FIGS. The structure can be greatly simplified by omitting all of the elements 29 and the like.
[0016]
【The invention's effect】
As described above, since the mechanical seal device according to the present invention is configured, the following special effects can be obtained.
[0017]
That is, lubrication and shaft sealing liquid can be supplied from the pressure accumulating tank to the seal housing in which the mechanical seal is inserted to seal the shaft. Moreover, even if the pumping liquid leaks from the seal housing, the leaked pumping liquid can be received in the housing charging chamber in which the seal housing is mounted, so that the bearing device is not affected. . Therefore, even if the corrosive pumping liquid leaks, the rotating shaft and the bearing device which are not made of the corrosion resistant material are not damaged. Also, even if the pumping liquid containing the slurry leaks, the bearing device is not damaged, so that the proper operation of the pump can be continued.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.
FIG. 2 is a right side view of FIG.
FIG. 3 is a longitudinal sectional view of a first conventional example.
FIG. 4 is a longitudinal sectional view of a second conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating shaft 13 Mechanical seal 32 Seal housing 33 Housing loading chamber 34 Bearing device 37 Accumulator tank

Claims (1)

A mechanical seal that seals the rotating shaft of the shaft-sealed device, a seal housing in which the mechanical seal is mounted, and a pressure accumulation tank that supplies lubrication and shaft sealing liquid to the seal housing; A mechanical seal device, which is rotatably supported by a bearing device through a housing loading chamber in which a housing is loaded.

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