JP3037623U - Pump shaft sealing device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A low-quality heavy oil is used as a fuel for a marine diesel engine, and the problem of damaging the shaft sealing portion and the drive shaft of a pump that supplies the fuel has not been solved. SOLUTION: An oiler 25 containing lubricating oil is arranged at a position higher than a shaft sealing portion of a pump A, and an oil supply pipe line 26 connected to the oiler 25 is provided between a mechanical seal 19 and an oil seal 20. The lubricating oil in the oiler 25 is naturally connected to the space 33 above the mechanical seal 19 by connecting to the pipe joint 28 communicating with the space 33.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a shaft seal device for a pump that supplies low-quality fuel oil such as C heavy oil to a diesel engine or the like.

[0002]

[Prior art]

 FIG. 3 is a vertical cross-sectional view of a toothed wheel pump A showing an example of a positive displacement pump that supplies fuel oil to a marine diesel engine. Inside a casing body 3 mounted on a pump bed 2, an upper surface and a lower surface are provided. A gear accommodating chamber 4 that is open to the outside, a suction port 5 and a discharge port 6 that communicate with the gear accommodating chamber 4 from the outside, and the upper and lower surfaces of the gear accommodating chamber 4 are covered with an upper cover 7 and a lower cover 8, respectively. A frame 9 for mounting an electric motor (not shown) is mounted on the casing body 2. The pump casing 1 is configured as described above.

A pair of upper and lower plain bearings 10, 10 and a pair of upper and lower plain bearings 11, 11 are provided in the casing body 3, and a drive shaft 12 is rotatably supported by the flat bearings 10, 10. The drive gear 13 inserted into the gear accommodating chamber 4 is mounted and fixed by the key 14. A driven shaft 15 is rotatably supported by the plain bearings 11, 11, and a driven gear 16 which is inserted into the gear housing chamber 4 and meshes with the drive gear 13 is mounted on the driven shaft 15 and is fixed by a key 17.

The upper end of the drive shaft 12 penetrates a cylindrical seal housing 7 a extending to the upper cover 7, and is connected to the output shaft of the electric motor via a coupling 18. Inside the seal housing 7a, a mechanical seal 19 and an oil seal 20 that seal a gap with the drive shaft 12 are provided, and a seal cover 21 is attached to an end surface of the seal housing 7a. A safety valve 22 attached to the casing body 3 communicates with the discharge port 6 of the casing body 3.

When the drive shaft 12 rotates due to the start of the motor, the drive gear 13 and the driven gear 15 rotate while meshing with each other, and low-quality fuel oil is delivered from the intake port 5 to the discharge port 6 via the gear housing 4. , Passes through a delivery pipe (not shown) connected to the discharge port 6 and is delivered to the marine engine. When the pressure in the discharge port 6 rises above the set safety limit pressure, the safety valve 21 operates and some fuel oil is returned to the suction side, and the pressure in the discharge port 6 becomes normal.

[0006]

[Problems to be solved by the device]

 Of the low-quality fuel oil pressurized in the gear accommodating chamber 4, the fuel oil that passes through the gap between the drive shaft 12 and the plain bearing 11 and reaches the inside of the seal housing 7a is exposed to the outside by the shaft seal portion (mechanical seal 19). Leakage is blocked. The low-quality fuel oil that has been prevented from leaking is gradually solidified and hardened inside the shaft seal.

In particular, when the operation of the pump is stopped, the oil temperature in the shaft seal portion is lowered and the viscosity and hardness of the fuel oil are increased, so that there is a problem that the drive shaft and the shaft seal portion are damaged at the start of operation. When the temperature of the fuel oil is high, the leaked oil from the mechanical seal 19 comes into contact with the outside air, and the oil temperature lowers to become solidified and carbonized sludge. This sludge will damage the sliding surface of the mechanical seal, and especially the damage will occur when the pump is restarted after it is stopped. The present invention aims to solve such problems.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the pump shaft sealing device of the present invention is a positive displacement pump that pressurizes and delivers a highly viscous fluid by rotation of the drive shaft of the pump. The gap is sealed with a mechanical seal and an oil seal, a shaft seal part is provided to prevent leakage of high-viscosity fluid, and an oiler containing lubricating oil is placed above the shaft seal part. It is characterized in that an oil supply conduit communicating with the mechanical seal is provided. It is advisable to provide a gas vent line extending from the mechanical seal above the oiler and having an open end opening to the atmosphere at the end.

[0009]

[Embodiment of the invention]

 Since the present invention is an improvement of the pump shaft sealing device and is the same as the conventional example except for the pump shaft sealing portion, the same parts as those of the conventional device are denoted by the same reference numerals and detailed description thereof will be omitted. To do. An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the outer appearance of a pump shaft sealing device, and FIG. 2 is a vertical cross-sectional view showing the internal structure of the pump shaft sealing device.

As shown in FIG. 1, the leg portion 23 a of the column 23 is attached to the upper surface of the casing body 3, and the support beam 24 is provided at the upper end of the column 23. The oil supply pipe 26 is attached to the lower end of the oiler 25 which accommodates the lubricating oil inside, the oil supply pipe 26 is fixed to the support beam 24, and the T-shaped pipe joint 27 is connected to the end of the oil supply pipe 26. To do. A pipe joint 28 that communicates with the mechanical seal 19 of the shaft seal portion is provided at the upper end of the seal housing 7 a, and an end portion of a pipe passage 29 that extends laterally from the pipe joint 26 is connected to the pipe joint 28. As the oiler 25, a commercially available product that is easily available and inexpensive can be used.

Lubricating oil in the oiler 25 prevents leakage of hot fuel oil from the shaft sealing portion to the outside air, gradually solidifying and hardening, and the oiler 25 is placed at a position higher than the mechanical seal 19. The lubricating oil that is attached and stored in the oiler 25 is naturally supplied to the mechanical seal 19 by its own weight. A cock 30 for drain drainage is attached to the lower opening of the T-shaped pipe joint 26.

A pipe joint 31 that communicates with a space 33 between the oil seal 20 and the mechanical seal 19 is attached to the seal cover 21, and the middle portion of the gas removal pipe 32 whose one end is connected to the seal cover 21 is upward. It bends and rises to a position higher than the liquid level of the lubricating oil in the oiler 25, the end bends in a U shape, and the open end that opens to the atmosphere faces downward.

Next, the operation of the shaft sealing device for a pump configured as described above will be described. The lubricating oil in the oiler 25 is naturally supplied to the space 33 by its own weight not only when the pump is operating but also when the engine is not operating, and is stored outside the mechanical seal 19. Therefore, even if the high temperature fuel oil leaks from the mechanical seal 19, the fuel oil does not come into contact with the outside air and is mixed with the lubricating oil in the space 33. Therefore, the leaked fuel oil is neither solidified nor carbonized, and the sliding surface of the mechanical seal 19 is not damaged. Since the gas vent pipe 32 rises to a position higher than the liquid level of the lubricating oil in the oiler 25, the lubricating oil in the oiler 25 will not flow out from the end opening of the gas vent pipe 32.

[0014]

[Effect of the invention]

 Since the present invention is configured as described above, the structure is simple and extremely inexpensive, and the lubricating oil is naturally supplied to the shaft seal portion of the pump, and the low quality and high temperature fuel oil leaks in the shaft seal portion. By preventing the oil from solidifying, it is possible to reliably prevent damage to the shaft seal and drive shaft, which had been a problem in the past, and to improve pump reliability.

[Submission date] December 6, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

[Problems to be solved by the device]

Of the low-quality fuel oil pressurized in the gear accommodating chamber 4, the fuel oil that passes through the gap between the drive shaft 12 and the plain bearing 11 and reaches the inside of the seal housing 7a is exposed to the outside by the shaft seal portion (mechanical seal 19). Leakage is blocked. Fuel oil low quality which is prevented from leaking, the (shaft seal inside or deteriorated staying between the moving parts, such as Sprint grayed the shaft seal box inside the mechanical seal is retained so maze and dead ends liable Because of this, carbonization occurs due to heat generation and oxidation of the sliding parts of the mechanical seal, resulting in accumulation. In particular, during shutdown of the pump, without replacement of the oil by pumping action, to or stopped the heating of anchoring during soil pumps, viscosity of the fuel oil is increased oil temperature in the shaft sealing portion is lowered Te, when starting the next pump, there is a problem of not impede the movement of the spring of any moving parts of the mechanical seal, that carbonized-deposited from damaging the shaft and shaft seal (mechanical seal).

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

When the temperature of the fuel oil is high, the leaked oil from the mechanical seal 19 comes into contact with the outside air, the oil temperature lowers, and it solidifies to form sludge. This sludge will damage the sliding surface of the mechanical seal, and especially the damage will occur when the pump is restarted after it is stopped. The present invention aims to solve such problems.

[Brief description of the drawings]

FIG. 1 is a front view showing the outer appearance of a shaft sealing device for a pump.

FIG. 2 is a vertical cross-sectional view showing the internal structure of a shaft sealing device for a pump.

FIG. 3 is a vertical sectional view of a pump.

[Explanation of symbols]

 A gear pump 1 casing 3 casing body 4 gear housing chamber 7a seal housing 12 drive shaft 13 drive gear 15 driven shaft 16 driven gear 19 mechanical seal 20 oil seal 21 seal cover 25 oiler 26 oil supply line 32 gas vent pipe

Claims (2)

[Utility model registration claims] 1. A positive displacement pump for pressurizing and delivering a high-viscosity fluid by rotating a drive shaft of the pump, wherein a gap between the casing of the pump and the drive shaft is sealed with a mechanical seal, A shaft seal portion for preventing leakage is provided, an oiler for containing lubricating oil is provided above the shaft seal portion, and an oil supply pipe line communicating from the inside of the oiler to the mechanical seal is provided. Pump shaft sealing device. 2. A shaft seal for a pump according to claim 1, wherein a degassing pipe line extending from the mechanical seal to above the oiler and having an open end opening to the atmosphere is provided at an end thereof. apparatus.