JPH0211969A - Sealing structure to rotating shaft - Google Patents

Abstract

PURPOSE: To provide a low-cost lip packing stretching in the radial direction in a hollow ring form by using at least one such lip packing as a spare packing and fitting it to a shaft or shaft bushing in tight contact thereto. CONSTITUTION: A packing 6 in a ring form is deformable elastically, and when no pressure medium is supplied to a cavity 7, its contacting edge 6' is positioned slightly apart from the oversurface of the bushing 2 owing to the elastic repulsion force. When pressure medium is supplied to the cavity 7, the edge 6' deforms so as to make pressure contact with the oversurface of the bushing 2, when the desired contacting pressure of the edge 6' is generated by adjusting properly the pressure of the medium. The packing 6 is positioned apart from the shaft 1 in normally operating condition, i.e., a filled packing 5.3 installed as facing the space S accommodating a lubricant is exerting its normal function.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sealing structure for a rotating shaft, in particular a sealing structure for a tubular member at the stern of a ship, having the features recited in the preamble of the first claim. It's about structure.

Prior Art This type of conventional closed structure (German Patent No. 202842
In No. 1, all radially extending lip seals are fitted and therefore the radially extending spare lip seals are also attached to a shaft or shaft pusher which is arranged so that the bearing is not axially displaced. Due to the fact that the shaft or pusher is movable axially relative to the shaft or relative to a bearing that is mounted in an axially fixed manner, a clearance is created at the contact edge of the seal. , so in these cases a radially extending pre-glue sop packing is used, one end free from the axial movement of the shaft or push top surface and the other end fixed above the shaft or push. .

OBJECTS OF THE INVENTION Obviously, the drawback of such an arrangement is that it requires a high production cost, but the additional radial lip seals in many cases provide greater operational safety. It outweighs the benefits it brings.

It is therefore an object of the present invention to overcome this drawback and to propose a solution in which a spare radial lip seal can be used at a relatively low cost.

Means for solving the problem and its operation The above problem is achieved by fitting at least one hollow ring-shaped radially extending lip seal closely to the shaft or shaft pusher as a radially extending spare lip seal, Connected to a pressure line for supplying a pressurized medium, in particular air, said hollow ring-shaped radially extending lip puncture assumes a position in one operating state in pressure contact with the shaft or shaft bushing, and in another In operation, it assumes a position spaced from these.
This is achieved by making it elastically deformable.

Hollow ring-shaped radially extending lip seals for shafts or shaft bushings are already known (DE 2 606 813, FR 2 315 045); The radially extending auxiliary lip seals relative to the radially extending main lip seals are not addressed;
- A radially extending main lip seal is addressed for devices requiring occasional shaft sealing.

It is clear that a hollow ring-shaped radially extending lip seal can be provided at relatively low cost. This is because this lip seal consists only of an elastically deformable hollow ring, which is connected to a compression source via a pressure line and a control.

In one embodiment of the features of the invention, the stern tubular member of a ship is sealed against external water and three radially extending main lip seals are arranged in parallel, the outer two of which are external water-tight. A radially extending reserve lip seal is arranged towards the water, the inner one towards the space containing liquid lubricant, in particular lubricating oil, and an inner radially extending main lip seal. Located in the front, towards the space containing the lubricant (
(See second claim).

Thus, in addition to the above-mentioned cost-reducing effect, the radially extending main lip seal directed into the lubricant-accommodating space easily prevents the lubricant from seeping into the external water. In turn, it is possible to meet strong demands for environmental protection.

In another embodiment, the liquid medium is sealed against a gaseous medium, in particular air, and there are two radially extending primary lip seals arranged in parallel towards the liquid medium, the radially extending A spare lip seal extending in the direction of the liquid medium is arranged in front of the radially extending main lip seal arranged towards the liquid medium side. reference).

At this time, the spare lip packing extending in the radial direction is
The cavity receives the pressure of pressurized water as a pressurizing medium, and a hole is formed in the vicinity of the contact edge of the cavity to communicate with the space filled with the gaseous medium. (see claim 4).

In this embodiment, if a groove is formed in the inner circumferential direction around the opening of the hole on the inner circumference of the ring of the spare lip packing that extends in the radial direction, a hydrodynamic action will occur and the hole will exit from the hole. A hydrodynamic effect occurs in which the incoming fluid is propelled towards the contact edge (see claim 5).

By such measures, slight leakage of lubricant from the hollow ring-shaped radially extending lip packing can be improved by using pressurized water.

Also, instead of a radially extending lip seal, a sliding ring seal can be used.

EXAMPLE In the closed structure shown in FIG. 1, the bushing (2) is on the screw shaft (1). The shaft (1) is attached to a bearing bush (not shown), which is supported by a member (3). Further, a sealed housing (4) is fixed to the bushing (2), and the housing (4) further includes housing rings (4,1) and (4,2) that are arranged side by side in close contact with each other.
, (4,3) , (4,4) , (4°5) and four radially extending lip gaskets (5,1) , (5
, 2), (5, 3), and (6).

Lip packing extending in the radial direction (5, 1), (5,
2) are arranged towards the external water (A), while the radially extending lip seals (5, 3) are arranged towards the space (S) containing the lubricant. In front of these seals, in the direction of the space (S) containing the lubricant, another radially extending lip seal (6) is arranged.

Lip packing extending in the radial direction (5, 1), (5,
2) and (5, 3) are formed as solid packings in the usual manner and act as main packings.

On the other hand, the radially extending packing (6) is formed as a hollow packing and acts as a spare packing.

The cavity (7) of the packing (6) is connected to the conduit (8) indicated by a broken line.
), and a closing part or a control part (not shown) is disposed in the pipe (8), and the pipe (8) is connected to the pipe (8).
The other end is connected to a compression source (not shown) for supplying pressure line air.

The hollow ring-shaped packing (6) is elastically deformable, and when the pressurized medium is not supplied to the cavity (7), its contact edge (6”) deforms due to the elastic repulsive force. (2) It is located at a position slightly spaced from the top surface.

When the pressurized medium is supplied to the cavity (7), the hollow ring-shaped packing deforms so that its contact edge (6°) comes into pressure contact with the upper surface of the bushing (2).

At this time, by appropriately adjusting the pressure of the pressurizing medium, it becomes possible to easily bring the contact edge (6'') into pressure contact with the desired contact pressure.

The hollow ring-shaped packing (6) is in a normal operating state, that is, when the filled packing (5, 3) facing the space containing the lubricant is performing its normal function. is spaced apart from the shaft.

If the aforementioned filled gasket fails or begins to leak, a detection and notification system (not shown) switches the hollow ring-shaped gasket (6) into the active position, making it an extremely valuable replacement gasket. Function.

FIG. 2 shows the closed structure of the shaft, in which a bush (2) is placed on the shaft (1).

The shaft (1) is supported by a bearing (not shown), and the bearing is mounted and supported by a member (3).

Further, a sealed housing (4) is fixed to the bushing (2), and the sealed housing (4) is made up of four housing rings (4,
1) , (4,2) , (4,3) , (4,4) and three radially extending lip gaskets (5,1) each fitted between the two said housing rings,
It consists of (5, 2) and (6).

All radially extending lip seals are then adjusted simultaneously and directed towards the water-filled space (W) as in the previous embodiment.

Lip packing extending in the radial direction (5, 1), (5,
2) is formed in the usual way as a solid packing and acts as the main packing, while the radially extending lip packing (6) is formed as a hollow packing and acts as a reserve packing. Patsukin (6
) is connected to the cavity (7) via a conduit (8) indicated by a broken line.
Connected to a compression source for supplying pressurized water. The hollow ring-shaped packing (6) has a thin hole (9) communicating with the outer space of the inner circumference of the ring near its contact edge (6°).
), and this hole (9) is for making it possible to always form a water film sufficient for lubrication of the contact edge (6゛) of the hollow ring-shaped packing (6). .

In the modification shown in FIG. 3, the thin hole (9)
In addition, # (1
0) is formed, and the hydrodynamic action promotes the generation of a water film from the hole (9) toward the contact edge (6"), thereby effectively performing lubrication. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a radially extending preliminary lip seal according to the present invention applied to the conventional sealing structure of a screier shaft, and FIG. 2 is a sealing of a liquid medium against a gaseous medium. FIG. 3 is a sectional view showing a radially extending extra lip seal according to the invention applied to a structure; FIG. FIG.

Claims (7)

[Claims] (1) at least one radially extending primary lip packing closely disposed on at least one shaft or shaft bushing and spaced apart from the shaft or shaft bushing during normal operation; at least one radially extending spare lip packing having a contact edge that assumes a position in pressure contact with the shaft or the shaft bushing when the primary radially extending lip packing fails; A hollow ring-shaped radially extending lip packing is applied to the shaft or to the shaft packing as a spare radially extending lip packing for sealing and is connected to a pressure line for supplying pressurized medium. is elastically deformable by the pressurizing medium of the pressure pipe, and its contact edge assumes a position in pressure contact with the shaft or the shaft bushing in one operating state, and in another operating state, the contact edge thereof is in pressure contact with the shaft or the shaft bushing. A closed structure for a rotating shaft, characterized in that it is capable of assuming a position spaced from the bushing. (2) The stern tubular member of the ship is sealed against external water (A), and the three radially extending main lip packings (5.1 to 5.3) are arranged in parallel, and the three main lip packings (5.1 to 5.3) are arranged in parallel. The outer two lip packings (5.1, 5.2) are arranged facing the outside water (A), and the inner one (5.3) is arranged toward the space (S) that accommodates the lubricant. ), and in front of the inner main lip packing (5.3), a spare lip packing (6) extends in the radial direction toward the space (S) for accommodating the lubricant. The sealing structure for a rotating shaft according to claim 1, characterized in that the structure is arranged such that: (3) The liquid medium (W) is sealed against the gaseous medium (L), and the two radially extending main lip packings (5) are arranged in parallel toward the liquid medium (W). .1, 5.2) and a radially extending preliminary lip packing (5.2) arranged in the direction of the liquid medium (W) in front of the main lip packing (5.2) facing the liquid medium. The sealing structure for a rotating shaft according to claim 1, further comprising a lip packing (6). (4) Spare lip packing (6) extending in the radial direction
) can be supplied with pressurized water as pressurizing medium, and in the vicinity of the contact edge (6') of said radially extending spare lip packing (6), said cavity (7) 4. The hermetically sealed structure for a rotating shaft according to claim 3, wherein a hole (9) is formed which communicates from the hole (9) to the gaseous medium side. (5) Spare lip packing (6) extending in the radial direction
) around the opening of the hole (9) on the inner periphery of the ring,
A groove (10) is formed in the inner circumferential direction of the ring, and the contact edge (6') is formed from the hole (9) by hydrodynamic action.
5. The sealing structure for a rotating shaft according to claim 4, wherein the structure promotes the flow of fluid in the direction shown in FIG. (6) The sealing structure for a rotating shaft according to claim 1, wherein a hollow ring-shaped spare packing ring is provided for each lip packing extending in the radial direction. (7) A sealing structure for a rotating shaft according to claim 1 or 2, wherein the contact pressure of the lip packing extending in the radial direction of the hollow ring shape is adjustable. .