JPS6335873B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a stern tube sealing device used in water (or oil) lubricated bearings for ships, etc., in which a stationary side seal mechanism and a rotating side seal mechanism are attached to a propulsion shaft penetrating the stern tube. The objective is to obtain high sealing performance and lubricity by forming a magnetic field by fitting the annular water-stop ribbon body of the fixed-side sealing mechanism with an axial fluid, etc.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a stern tube sealing device for a water-lubricated bearing, in which a rotating-side sealing mechanism 1 and a stationary-side sealing mechanism 2 are integrally provided inside the hull. First, the sealing mechanism 1 on the rotation side fixes annular mirror plates 5, 5 to a holder 4 fitted onto a propulsion shaft 3, and bolts a cone portion 4' having a split groove of the holder 4 through a cone ring 6. By tightening at 7,
It is fixed to the propulsion shaft 3. 8 is an O-ring fitted between the propulsion shaft 3 and the holder 4. Next, the fixed side seal mechanism 2 is equipped with a rubber bearing 9, and the hull 1
The stationary side sealing mechanism main body, that is, the casing 14, in which the emergency sealing device 13 is fitted, is integrally attached to the intermediate flange 12 fixed to the end of the stern tube 11 attached to the stern tube 11 with bolts 14', etc. It consists of a lid body 16 fitted so as to be swingable in the axial direction and radial direction of the propulsion shaft 3 via a fixed water-stop bellows 15, and an annular water-stop ribbon body 17 fitted to the lid body 16. The end face of the annular water-stopping ribbon body 17 and the annular mirror plate 5 collide, and the rotary-side seal mechanism 1 and the stationary-side seal mechanism 2 come into sliding contact at the collision portion, thereby blocking water. Moreover, the lid body 16
The cylindrical body 18 is screwed into threaded holes extending in the axial direction at appropriate intervals in the flange portion of the casing 14, and a guide pin 19 erected in the axial direction on the outer peripheral edge of the casing 14 is loosely inserted. coil spring 2
0 is inserted between the end face of the cylinder 18 and the casing 14.
By rotating the cylindrical body 18 and moving it forward and backward, the pressing force of the coil spring 20 can be adjusted, and the contact force between the annular water stop ribbon body 17 and the annular mirror plate 5 can be adjusted. There is. 14″
is a cover that covers the vicinity of the seal part. The annular mirror plate 5 is made of two annular plates fitted into fitting portions 21 formed in the end face of the holder 4, and a spring pin 22 is driven into a mounting hole penetrating the annular mirror plate 5 and the holder 4. It is fixed to the holding body 4. Water-stopping O-rings 23, 23 are fitted between the side surface of the fitting portion of the holder 4 and the inner circumferential end surface of the annular mirror plate 5 to prevent water from leaking from the portion. One of the annular mirror plates 5 is in contact with the annular water stop ribbon body 17, and the other one is a spare member for the liner and for replacement. Next, the annular water-stop ribbon body 17 is made by spirally forming a layered tape made of cloth, tetrafluoride resin, etc., rubber magnets, and metal rope, and wrapping a thread-like sealing material around the outer circumferential surface to form a flange shape. Ground packing 2 which is hardened with packing material to fill in the step at the end of the ribbon and also serves as a water seal.
4, and is fitted into the annular groove 25 of the lid 16 and fixed via a gland packing presser 26. 27 is a ring-shaped rubber gasket interposed between one side of the annular water stop ribbon body 17 and the lid body 16. In addition, an oil hole 28 is suitably drilled in the lid body 16, and the oil hole 28 provided in the rubber gasket 27 is connected to the oil hole 28.
7', and a magnetic fluid (a liquid obtained by dissolving iron oxide powder in silicone oil, which forms a magnetic field even though it is a fluid and sticks to the gap between the layers of the ring-shaped water stop ribbon body 17) (a general term for fluids with properties).

Next, the structure of the annular water-stop ribbon body 17 that is better for filling the magnetic fluid will be described. It includes a tetrafluorocarbon resin ribbon 17a, a rubber magnet ribbon 17b,
The metal ribbon 17c is wound in three layers, and the magnetic fluid J is supplied from the opposite side of the rotating sliding surface using a supply device P such as a pump.
When the magnetic fluid J is replenished through the check valve, the magnetic fluid J remains in the magnetic field created in the gap between the ribbon tapes and fills the gap, thereby increasing the sealing performance and at the same time serving as a substitute for lubricating oil. With such a configuration, it is possible to set a low sliding surface pressure with the annular mirror plate 5, which has the advantage of reducing wear and torque. In this case, the rubber magnet ribbon functions to magnetically attract the magnetic fluid J, and the metal ribbon 17c functions to smooth the flow of the magnetic fluid J. Furthermore, by removing the rubber magnetic ribbon 17b, making a two-layer winding using a metal wire, and electrically exciting the wire itself, the strength of the magnetic field can be adjusted. Whether a magnetic field is formed in the center of the annular water-stopping ribbon body 17 to magnetically fill the magnetic fluid, or whether a magnetic field is created throughout the ribbon body depends on the application. Furthermore, high sealing performance and lubricity can be obtained by energizing the mirror plate 5 side or by energizing both sides to arbitrarily attract the magnetic fluid to the gap between the sliding surface and the ribbon.

Next, as another example of the annular water-stop ribbon body 17, a three-layer winding of a tetrafluoride resin ribbon 17a, a rubber magnet ribbon 17b, and a corrugated metal plate 17d may be used. The same effect as the annular water stop ribbon body 17 can be obtained. Next, a seawater passage 30 is bored in the lid body 16 and opens into the seawater filling chamber 29, which is composed of the propulsion shaft 3 and the seal mechanisms 1 and 2, and is connected to the outside through a pipe. The pressure is now adjusted. The emergency sealing device 13 consists of an annular rubber 32 fitted in an annular groove 31 bored on the inner circumference side of the casing 14 of the stationary side sealing mechanism 2, and a groove with a generally-shaped cross section is formed on the outer circumferential surface of the annular rubber 32. Groove bottom 3
2a, a fitting hole 33 is bored at an appropriate gap toward the axis of the propulsion shaft 3, and a rod-shaped pressing piece 34 with a flange made of carbon, tetrafluoride resin, etc. is inserted into the fitting hole 33.
is inserted so that the lower surface of the flange is in contact with the upper surface of the groove bottom 32a, and the bottom surface of the rod-shaped portion is exposed to the lower surface of the bottom 32a of the annular rubber 32, and a metal ring 35 is placed on the upper surface of the groove of the annular rubber 32 in the form of a lid. The inner circumferential surface of the intermediate ring 35 and the outer circumferential end surface of the pressing piece 34 face each other. Each pressing piece 3 of the interlocking ring 35
A small hole 36 is bored at a position in contact with the inner ring 35, and an air passage groove 37 is bored in the annular groove 31 surface of the casing 14 in contact with the inner ring 35, and communicates with each of the small holes 36. Also, the air passage groove 37
An air passage 38 communicating with the casing 14 is bored in the casing 14 and connected to a pipe for supplying compressed air (not shown). 39 is a seawater passage for replenishing seawater to the seawater filling chamber 29 when the emergency sealing device 13 provided on the intermediate flange 12 is used (the pipe connected to the seawater road 30 is reconnected). When compressed air is fed into the sealing device 13 from the air passage 38 in an emergency, the air is forced into the groove of the annular rubber 32 through each small hole 36 through the air passage groove 37 along the outer periphery of the interring 35. Then, each pressing piece 34 and the bottom 32a of the annular rubber 32 are pressed against the propulsion shaft 3, and the pressing pieces 34 made of elastic rubber and the material with a small friction coefficient work together to block water, so that the shaft Burn-in can be prevented. Especially the pressing piece 34
If carbon is carbon, the friction with the propulsion shaft 3 turns the carbon into powder, which adheres to the outer circumferential surface of the propulsion shaft 3 and acts as a lubricant, further improving the sliding between the propulsion shaft 3 and the annular rubber 32 and preventing seizure of both. completely prevent. Moreover, by making the pressing piece 34 have the same dimensions on the upper and lower sides with the flange as the center, it can be used inverted when the pressing surface becomes worn.

As described above, the stern tube emergency sealing device according to the present invention consists of an annular rubber body with a groove formed on the outer circumferential surface attached to the sealing mechanism main body on the fixed side along the outer circumferential surface of the propulsion shaft. By inserting press pieces made of carbon or synthetic resin into fitting parts formed at appropriate intervals on the bottoms of opposing grooves, and attaching a cover body with an air inlet pipe to the groove mouth to pressurize air into the grooves. The bottom of the groove and the pressing piece are pressed against the outer circumferential surface of the propulsion shaft, and the propulsion shaft is tightened with rubber to block water, and at the same time, the pressing piece made of carbon or synthetic resin with a small friction coefficient reduces friction and prevents seizing of the propulsion shaft. can be prevented. In particular, according to the present invention, a magnetic field is formed in the annular water-stop ribbon body 17 using a rubber magnet or the like to attract the magnetic fluid and fill the gap between the sliding parts, thereby improving the sealing performance, and the magnetic fluid also has a lubricating function. In the relationship with the mirror plate 5, the beneficial effect of reducing friction and reducing torque can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a stern tube equipped with a magnetic seal device according to the present invention, Fig. 2 A is a perspective view of the emergency seal device, Fig. 2 B is a perspective view showing the same cross section, and Fig. 3 is an annular water stop. A perspective view of the ribbon body, FIG. 4 is another embodiment of the annular water stop ribbon body. DESCRIPTION OF SYMBOLS 1... Seal mechanism on rotating side, 2... Seal mechanism on stationary side, 3... Propulsion shaft, 5... Annular mirror plate, 9
... bearing, 13 ... emergency sealing device, 14 ... casing, 15 ... water-stop bellows, 16 ... lid body,
17... Annular ribbon body, 24... Crund bag, 32... Annular rubber, 32a... Shape groove bottom,
33... Fitting hole, 34... Pressing piece.

Claims (1)

[Claims] 1. In a sealing device that is provided with a stationary side seal mechanism and a rotating side seal mechanism on a propulsion shaft penetrating a stern tube, and that shuts off water by causing a water stop ribbon body of the stationary side seal mechanism to collide with the rotating side seal mechanism. A sliding magnetic sealing device for a stern tube, etc., characterized by forming a magnetic field within a water ribbon body.