JPS5813781B2 - Pressure equalization structure of shaft sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure equalization structure between shaft sealing devices at both shaft ends of a barrel type turbo compressor or the like.

First, these conventional structures and their problems will be explained with reference to FIG.

FIG. 1 is a cross-sectional view of the upper half of the right end cover 2 up to the main casing 1, including the horizontally placed turbo compressor shaft 13.

The casing of the barrel type turbo compressor is main casing 1,
It consists of an inner casing 5 that fits into this, an end cover 2 that is fastened to the main casing 1 by a split key 4, a shaft sealing device 14 that is housed between the inner periphery of the end cover 2 and a shaft 13, and the like.

Here, the shaft sealing device 14 includes several groups of unit shaft sealing groups (fin groups) 11 such as labyrinths and oil films arranged in tandem in the axial direction.
They are typically arranged with a chamber 12 between each.

In order to equalize the pressure between the left and right end covers of this chamber 12, these are connected by a hole 6 provided in the end cover, a pressure equalizing pipe 3, etc.

Several chambers 12 are lined up along the axis 13, but these chambers must be pressure-equalized between the innermost chambers and the next chambers between the end caps, so several pressure-equalizing pipes are also used. (The holes 6 and 6' in FIG. 1 are shown in different radial directions on the same plane for convenience.

) One end cover 2 is fastened to the main casing 1 with a split key 4.

To disassemble the compressor, insert the key 4 into the end cover 2 from the state shown in Figure 1.
It must be pulled out toward the center of the end cap, and that much space is required on the outer surface of the end cap.

This space competes with the space for the drawer reservoir of the pressure equalizing pipe 3, and in some cases, the diameter of the end cover 2, that is, the diameter of the main casing 1, may have to be increased accordingly.

In addition, several of the pressure equalizing pipes 3 will pass outside the machine,
The machine's movements become more and more cluttered.

Furthermore, when disassembling and reassembling the machine, it takes time to remove and restore the piping.

Therefore, in the present invention, as shown in FIG. 2, a hole 9 is formed in the inner casing 5 and the hole 9 is used for pressure equalization to solve the above-mentioned problems.

In FIG. 2, the hole 6 is a hole made in the wall thickness of the end cover 2 so as to communicate with the chamber 12, as in the conventional case.

This hole 9 is connected to a hole 10 formed on the inner surface of the end cover 2.

A pressure equalizing hole 9 is formed in the inner casing 5 through its wall thickness in the axial direction.

When the end cover 2 is attached, it is connected to the hole 10 by the connecting member 7.

An example of a connecting member 7 is shown in cross section in FIG. 3, in this case with an O-ring 8 attached.

This connecting member also serves to absorb any discrepancies between the holes 9 and 10 caused by machining of the end cover 2 and the inner casing 5, assembly errors, temperature rise, expansion or distortion due to pressure, etc.

However, the connecting member between the holes 9 and 10 is not limited to such a piece, and may be an O-ring, a bellows, or the like.

By adopting the above structure, the problems of the conventional method mentioned above are almost solved, and the pressure equalizing pipe 3 of the conventional method is also solved.
Danger due to damage to the equipment can also be avoided.

If the pressure inside the pressure equalization hole is to be taken out to the outside, an outlet like 15 may be attached to the pressure equalization hole 9 through the main casing 1 and the inner casing 5.

Further, in this structure, since the pressure inside and outside of the inner casing 5 is kept approximately the same, there is no need to worry about a decrease in strength due to the opening of the hole 9 in the inner casing 5.

The twisted inner casing is a horizontally split type and requires bolts to hold the top and bottom together, so it has a certain amount of wall thickness, so there is no need to make it particularly thick to fit through the pressure equalization hole.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example, and shows a cross section including the soil half of the right end cover and its vicinity, including the axis, and FIG. 2 shows the present invention in the same place. Figure 3 shows the cross section of the connecting member 1...main casing, 2...
・End cover, 3... Equalizing pipe h4... Key, 5... Inner casing, 6... Hole, 7... Connection member, 8...
・O-ring, 9...pressure equalization hole.

Claims (1)

[Claims] 1. When each of the shaft sealing devices for both end caps of a barrel-type turbo compressor is composed of several unit shaft sealing rings 11 and a chamber 12 between them, the end cap has a wall from the chamber 12 to the end cap within its wall thickness. A hole 10 communicating with the inner surface is bored, and the hole 10 in both end covers is connected to a pressure equalizing hole 9 provided in the wall thickness of the inner casing 5 in its axial direction.
Pressure equalization structure of shaft sealing device connected through.