JPH07280101A - Shaft seal device and shaft seal method - Google Patents

Abstract

PURPOSE:To ensure a sealing effect via the application of the elasticity of a rubber tube itself, regarding a shaft seal devise using a packing material of rubber tube. CONSTITUTION:This shaft seal device is so constituted that a bat bag type elastic tube 5 with a nozzle 6 is internally evacuated and flattened, and the tube 5 so flattened is wound around a shaft 4, thereby forming an elastic tube layer. Furthermore, after the layer is coupled to the wail hole 2 of a housing 1 or the like, the nozzle 6 is opened for the atmospheric air to flow into the tube 5 for the expansion thereof, thereby sealing space between the shaft 4 and the housing 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft sealing device for a shaft that penetrates a wall hole of a casing, a housing or the like, which is easy and easy to mount and dismount, and has durability of its sealing material. Is high, and the sealing material can be repeatedly used.

[0002]

2. Description of the Related Art A shaft, rod, cable or the like (hereinafter collectively referred to as "shaft") that penetrates a wall hole of a hermetically sealed housing, casing or the like, is provided between the wall hole and the shaft. A shaft sealing device is used as a means for sealing the. Typical examples of the shaft sealing device include a gland packing, a U packing, a V packing, an O ring, and a mechanical seal as a shaft sealing device for a rotary shaft. As a shaft seal device for high pressure, a U packing, a V packing, and an O ring are optimal because they are simple and economical. However, these have a small allowable range for the diameter of the shaft on which the seal ring is mounted and the inner diameter dimension error of the wall hole, and the surface of the shaft on which these seal rings are mounted and the inner surface of the wall hole (hereinafter these are referred to as "packing mounting"). High finishing accuracy is required for the surface. Therefore, these cannot be applied to those in which the dimensions of the wall hole and the shaft, the surface finish of the mounting surface is relatively rough, and those in which the dimensions and the shape of the wall hole and the shaft are slightly changed. Wall hole,
As a simple shaft sealing device that can secure relatively good sealability for shaft dimensions, those with a relatively rough surface finish on the mounting surface, wall holes, those with slightly changed shaft dimensions and shapes,
Use a relatively soft rubber tube as a packing material, fill it with high pressure gas or high pressure air, and inflate it.
There is a shaft sealing device that presses against the inner peripheral surface of the shaft and the wall hole. This is excellent in that the packing material is flexible, can follow the deformation of the diameter of the shaft and the inner diameter of the wall hole, and the shape of the shaft and the wall hole, and is relatively simple. However, since a high internal pressure is constantly applied to the rubber tube, the internal pressure decreases with the passage of time, and the sealing performance deteriorates.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to enable a shaft sealing device using a packing material made of a rubber tube to be sealed by utilizing the elasticity of the rubber tube itself.

[0004]

[Means for Solving the Problems] The measures taken to solve the above problems are constituted by the following elements (a) to (c). (A) The sealing material is a band-shaped elastic tube having a nozzle, and (b) the elastic tube whose inside is evacuated and flattened is wrapped around a shaft to form an elastic tube layer, ( C) After fitting the elastic tube layer into a wall hole of a housing or the like, the nozzle is opened to allow the atmosphere to flow into the elastic tube to expand the elastic tube, and the elastic tube layer seals between the shaft and the housing. thing.

[0005]

[Operation] When a flat elastic tube with a vacuum inside is wrapped around the shaft and wound, the elastic tube is flat and thin, so the outer diameter of the elastic tube layer wound around the shaft is smaller than the inner diameter of the wall hole. Since it is small, it can be easily fitted into the wall hole of the housing or the like. When the nozzle is opened, air flows into the elastic tube, and the elastic tube expands due to its own elasticity. Therefore, the outer diameter of the elastic tube layer increases and the outer peripheral surface and the inner peripheral surface thereof are pressed against the inner peripheral surface of the wall hole and the outer peripheral surface of the shaft, respectively, so that the wall hole and the shaft are reliably sealed. When the shaft is disengaged, the nozzle is connected to a vacuum pump to remove air from the elastic tube, and the outer diameter of the elastic tube layer is reduced, so that the elastic tube layer is easily removed from the wall hole. Since the elastic tube layer once removed is not damaged in any way, it can be wound around the shaft and used again. By pre-coating the outer peripheral surface of the shaft and the inner peripheral surface of the wall hole with a non-adhesive adhesive material, it is possible to further seal the outer peripheral surface of the shaft and the inner peripheral surface of the wall hole and the pressure contact surface of the elastic tube layer. You can be sure.

[0006]

EXAMPLES Next, examples will be described with reference to FIGS. This embodiment is an example in which the present invention is applied to a plastic casing 1 in which an annular groove 3 is provided in an inner periphery of a wall hole 2 and a plastic tube 4 penetrates the wall hole 2. The inner diameter of the wall hole 2 is 60 mm, the inner diameter of the annular groove 3 is 70 mm, and the outer diameter of the tube 4 is 20 mm. The sealing material composed of the elastic tube 5 is an ethylene-propylene elastic tube having a chevron cross section,
Wall thickness t is 2.5 mm, tube thickness T is 7 mm, width w
The length L is 15 mm and the length L is 600 mm. A nozzle 6 that can be opened and closed by a cap is provided on a side surface (or an appropriate place such as an end portion) of the intermediate portion. When the elastic tube 5 is evacuated, the elastic tube 5 becomes a flat strip having a thickness of 5 mm or less. When this is overlapped and wound on a plastic tube 4 having a diameter of 20 mm, an elastic tube having a length of 600 mm is wound about 4 times. Since the outer diameter of the elastic tube layer 7 at this time is less than 60 mm, the inner diameter is 60 m.
It is easily inserted into the wall hole 2 of m. When the position of the elastic tube layer 7 is aligned with the annular groove 3 of the wall hole 2 and the cap of the nozzle 6 is removed, the elastic tube 5 expands by its own elasticity, and the outer peripheral portion of the elastic tube layer 7 is It fits in the annular groove 3, and its outer peripheral surface is pressed against the inner peripheral surface of the annular groove 3. In this state, the elastic tube layer 7 is 3 m in the radial direction.
It is in a state of being pressed against m. That is, the elastic tube layer 7 receives a compressive stress when it is compressed by 3 mm in the radial direction, and is pressed against the inner peripheral surface of the annular groove 3 and the outer peripheral surface of the plastic tube 4 by the stress. The pressure contact force between layers in the elastic tube layer is equal to this. By preliminarily forming a non-adhesive adhesive material layer on the inner peripheral surface of the annular groove 3 and the outer peripheral surface of the plastic tube, the elastic tube layer is formed between the inner peripheral surface of the annular groove 3 and the outer peripheral surface of the plastic tube. The sealing property of can be further improved. By connecting a vacuum pump to the nozzle 6 and evacuating the elastic tube again, the elastic tube layer 7 has a diameter of 6 mm.
Since it is less than 0 mm, the elastic tube layer 7 is easily removed from the wall hole 2. The elastic tube layer is fitted into and removed from the wall hole by applying no external force to the elastic tube layer and by rubbing it against other objects, so this operation will not damage the elastic tube. Absent. Therefore, the elastic tube can be used repeatedly. Further, as shown in FIG. 6, on the lower surface of the elastic tube 5, small projections 5a parallel to the center lines of the two elastic tubes,
5a is projectingly provided, and a similar small protrusion 5b is provided on the upper surface.
By projecting, it is possible to enhance the sealing performance of the elastic tube 5.

[0007]

[Effect] What solved the above-mentioned problems of the present invention is not yet known. Therefore, it is an effect peculiar to the present invention that the above problems are solved and all the above problems of the prior art are solved. That is, the sealing work between the wall hole and the shaft penetrating the wall hole can be performed easily and quickly, the elastic tube is compressed, and the elastic force secures the surface pressure against the sealing surface. It does not cause a sealing failure due to internal pressure leakage, and therefore has excellent durability. Also, the elastic tube can be well adapted to the shaft diameter, the wall hole diameter, and some deviations of these shapes, so that the shaft diameter, the wall hole diameter, and some deviations of these shapes If so, the sealing performance is not impaired, and the same elastic tube can be applied to combinations of wall holes of various diameters and shafts of various diameters. Therefore, the manufacturing cost of the sealing material of the shaft sealing device can be reduced. Further, since the elastic tube is not damaged by its attachment / detachment, the elastic tube as a sealing material can be repeatedly used.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an example.

FIG. 2 is a perspective view of a cross section of an elastic tube.

FIG. 3 is a perspective view of an elastic tube.

FIG. 4 is a cross-sectional view of a state in which an elastic tube is wound around an axis.

FIG. 5 is a side view showing a state in which the elastic tube is wound in layers.

FIG. 6 is a perspective view of the elastic tube in which two small projections are provided on the lower surface of the elastic tube and one similar small projection is provided on the upper surface thereof.

[Explanation of symbols]

 1 ... Casing (housing) 2 ... Wall hole 3 ... Annular groove 4 ... Tube (shaft) 5 ... Elastic tube 6 ... Nozzle 7 ... Elastic tube layer

Claims (2)

[Claims] 1. A band-shaped elastic tube having a nozzle,
The inside is evacuated to make it flat, and the elastic tube layer is formed by stacking it on a shaft and winding it, and after fitting the elastic tube layer into the wall hole of the housing, etc., open the nozzle to open the elastic tube to the atmosphere. A shaft sealing device that seals between the shaft and the housing by inflating the elastic tube. 2. An elastic tube whose inside is evacuated and flattened is wrapped around a shaft, and an outer peripheral portion of an elastic tube layer formed by stacking the elastic tube around the shaft is fitted into a wall hole of a casing, After that, the nozzle of the elastic tube is opened, air is introduced into the elastic tube, the elastic tube is expanded, and the elastic tube layer seals between the shaft and the wall hole.