JPS6324288Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealing device that can be applied to all rotating machines used in high-pressure water, such as oil-immersed pressure-equalizing slip springs and submersible electric motors.

Conventionally, equipment used in high-pressure sewage has adopted a pressure-equalizing type in which a liquid such as oil is sealed inside. Particularly in the case of electrical equipment, it is important to maintain internal electrical insulation, so water should not infiltrate from the outside. In rotating machines, there is the greatest risk of water intrusion from the shaft seal, so special care is taken in this sealing method, and conventionally double seals are often applied to improve reliability. In this case, since the area surrounded by the two seals becomes a closed room, a pressure equalization mechanism is required to absorb changes in volume due to changes in pressure and temperature.

A typical example of a conventional sealing device is shown in FIG. In the figure, reference numeral 1 denotes a device case, in which an insulating liquid 2 is sealed, and changes in its volume are adjusted by a bladder 3, so that external pressure and internal pressure are approximately equalized. Reference numeral 4 denotes an axis of a rotating body 8, and two seals 5 are applied to the penetrating portion of the case. Although FIG. 1 shows an O-ring seal, other mechanical seals or the like may also be used. In the part sandwiched by this seal 5,
A bladder 6 is provided as a pressure equalization mechanism. Further, 7 indicates a bearing. However, in this conventional structure, since the bladder 6 is located outside, it is susceptible to external damage, and if the bladder 6 is damaged due to an abnormal pressure difference in the pressure equalizing chamber sandwiched between the shaft seals 5, There was a risk that water or foreign matter could enter the seal chamber, causing rust, staining, and damage.

This invention was proposed in order to eliminate the above-mentioned conventional drawbacks, and the bladder for equalizing the seal chamber pressure was moved from the outside to the inside of the machine. The pressure equalization means for the seal part is placed inside the case that surrounds the rotating machine, so there is no risk of injury, and at the same time the environment is improved, improving corrosion resistance. It is an object of the present invention to provide a sealing device that can maintain a good condition without foreign liquid or foreign matter from entering the sealing chamber even if it is damaged.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment of the present invention.
In the figure, reference numeral 1 denotes a case of a rotating machine, in which a liquid 2 such as oil is sealed, and a bladder 3 equalizes the internal and external pressures. 4 is the shaft of the rotating body 8, and the seal 5 (in this figure O
(Although a ring is shown, other sealing methods such as a mechanical seal can also be used) to provide a double seal with the outside. In order to equalize the pressure in the seal chamber between these double seals, a bladder 9 is provided inside the machine. Note that 7 indicates a bearing.

Next, to explain the operation, inside the seal chamber sandwiched between the seals 5 and the bladder 9 that communicates with it, there are:
During assembly, the inside of the machine is filled with the same liquid 2, and the volume of the bladder 9 changes according to changes in pressure and temperature, so that the pressure inside the machine and the sealing chamber are equalized, and the pressure outside is also equalized.

As explained above, in this invention, the pressure equalization means is provided inside the case, so there is no damage to this pressure equalization means due to external trauma, and even if it is damaged, clean liquid inside the machine will flow into the pressure equalization chamber. In addition to maintaining equal pressure inside and outside, if the pressure equalization means is installed at the bottom of the shaft, even if seawater intrudes into the case due to a defective external seal, the seawater will collect in the pressure equalization means and will not flow into the cabin. can prevent flooding.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an example of a conventional sealing device, and FIG. 2 is a side sectional view of a sealing device showing an embodiment of the present invention. Explanation of the main parts of the diagram, 1... Case, 2... Liquid, 4... Shaft, 5... Seal, 7... Bearing, 8...
... Rotating body, 9... Bladder (pressure equalization means).

Claims (1)

[Scope of utility model registration request] A sealing device for a shaft seal of a rotating machine used underwater, characterized in that pressure equalization means for the coaxial seal is disposed inside a case surrounding the rotating machine.