JPH0332477Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an improvement of a stern tube shaft sealing device.

As schematically shown in Fig. 1, the propeller shaft d, which connects the propeller b, which is the propulsion body of the vessel a, and the engine e becomes longer in accordance with the size of the vessel a, and also in accordance with this length. some bearings
The ship is equipped with a stern tube shaft seal f to prevent seawater from leaking into the ship, but sometimes galvanic corrosion occurs on the propeller shaft d, or there is a current leakage, and this must be removed. There is a need. Conventionally, as a countermeasure for this, a grounding device g made of carbon material was brought into contact with the propeller shaft d or a sleeve (not shown) fitted over the propeller shaft, and a conductive wire extending from the grounding device g was grounded to the ship's hull. According to this conventional example, the grounding device g
Because it was installed as a single item and separate from other components, sufficient maintenance was not performed, and there was a problem that the grounding effect was poor.

In view of the above points, the present invention has been devised by using electrically conductive materials for all the constituent members from the propeller shaft to the hull, including the sliding members on the rotating and stationary sides of the end contact type stern tube shaft sealing device. The object of the present invention is to provide a stern tube shaft sealing device which solves the above-mentioned problems at once by making the shaft sealing device equipped with a grounding function in addition to a sealing function.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 2, 1 is a propeller shaft to which a propeller (not shown) is fixed on the left side of the figure;
A sleeve 2 made of copper alloy is fitted around its outer periphery. 3 shows a part of the hull, and seawater exists in space A in the figure. The stern tube shaft sealing device that prevents this seawater from entering the inside of the ship B is shown in its entirety by 4, and is a seal made of a conductive rubber material that is fitted onto the outer periphery of the sleeve 2 by the tightening force of a garter spring 6. It consists of a ring 5 and other fixed side members. The fixed side members include a copper alloy seal housing 7 fixed to the hull 3 with bolts (not shown), and a copper alloy mating ring fixed to the rear end surface of the seal housing 7 with bolts 9. 8, and the inner periphery of the front end surface of the mating ring 8 serves as a close sliding surface 10 on the fixed side with respect to the seal ring 5. 11 is an emergency water sealing device, and 12 and 13 are flushing pipes.

According to the stern tube shaft sealing device 4 having the above configuration, the hull 3
The anticorrosion current generated by the potential difference between the propeller and the propeller can be passed from the sleeve 2 to the hull 3 through the seal ring 5, mating ring 8, and seal housing 7, and can be grounded without using any other dedicated grounding device. be able to. Therefore, when regularly maintaining the device as a shaft sealing mechanism, maintenance as an earthing mechanism can be performed at the same time, and there is no additional effort required.
Can maintain earthing function. Moreover, unlike the conventional configuration using a grounding device connected to the hull via a conductive wire, all members of the seal ring 5, mating ring 8, and seal housing 7 that constitute the conductive path are annular, and the Due to its large area, the resistance to the current from the propeller shaft 1 side is extremely small. Therefore, even if an excessive charge is suddenly generated on the propeller shaft 1 or sleeve 2 due to electrical leakage from onboard equipment, the above conductive path can be used. The sleeve 2 and the hull 3 or the seal housing 7 with seawater A as the electrolyte medium can be quickly discharged through the
Preventing short circuit discharge between sleeve 2 due to galvanic corrosion
Corrosion of surfaces in contact with water can be reliably prevented.

Next, FIG. 3 shows a mechanical seal type stern tube shaft sealing device 14 as a second embodiment of the present invention. In other words, 1 is a propeller shaft to which a propeller (not shown) is fixed on the left side of the figure, 2 is a sleeve made of copper alloy, and 3 is a hull, and a seal housing made of copper alloy is attached to the hull 3 with bolts (not shown). 15 is fixed. Reference numeral 16 denotes a fixed sliding ring made of copper alloy that is fitted into the inner periphery of the cylindrical portion of the seal housing 15 through an O-ring 17 so as to be airtight and movable in the axial direction, and a coil spring 18 elastically loaded in the front end recess. It is elastically biased in the direction of a rotating ring 19, which will be described later. On the other hand, a rotating ring 1 made of copper alloy is attached to the outer periphery of the sleeve 2 with a bolt 21.
9 is fitted, so that the fixed sliding ring 16 closely slides against an annular sliding member 20 made of carbon material fixed to the front end thereof.

The stern tube shaft sealing device 14 configured as described above also seals the seawater present in the space A in the figure so that it does not intrude into the interior side B of the ship, and also prevents the electrical charge generated on the propeller shaft 1 or the sleeve 2. Electricity is supplied from the sleeve 2 to the hull 3 via the rotating ring 19, the annular sliding member 20, and the fixed sliding ring 16, and the effect is almost the same as that of the first embodiment.

As explained above, the present invention consists of a series of constituent members of the stern tube shaft sealing device that performs the shaft sealing function between the propeller shaft and the hull, made of highly conductive materials such as carbon and copper alloy. Since we have constructed a grounding device that conducts electricity between each member, it is possible to ground without using any other dedicated grounding device, which is extremely economical.Moreover, the conductive path made up of the entire stern tube shaft sealing device is Since its cross-sectional area is large and its electrical resistance is extremely low, it is possible to reliably remove the charge on the propeller shaft side and prevent electrolytic corrosion caused by short-circuit current to the hull side using seawater as an electrolyte medium. Additionally, the practical effects of the present invention are extremely large, such as being able to inspect both the shaft sealing mechanism and the grounding mechanism during one maintenance of the device, thereby streamlining the maintenance work.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the stern of the hull, and FIG. 2 is a half-cut sectional view of the stern tube shaft sealing device showing the first embodiment of the present invention.
FIG. 3 is a half-cut sectional view of a stern tube shaft sealing device showing a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Propeller shaft, 2... Sleeve, 3... Hull, 4, 14... Stern tube shaft sealing device, 5... Seal ring, 7, 15... Seal housing, 8...
Mating ring, 16...Fixed sliding ring, 18
...Coil spring, 19...Rotating ring, 20...
...Annular sliding material.

Claims (1)

[Scope of utility model registration request] Close sliding between the rotating side sliding member, which is externally fitted onto the propeller shaft through a sleeve or without the sleeve, and the stationary side sliding member, which is fixed to the hull through a housing member. A stern tube shaft sealing device for sealing seawater by motion, characterized in that the sleeve, the rotating side sliding member, the stationary side sliding member, and the housing member are made of a conductive material. Device.