JPS60355Y2 - Rotary joint for slurry transfer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotary joint used in an agitator in a soft ground improvement device.

Figures 1 and 2 are side sectional views showing examples of conventional slurry transfer rotary joints;
-n cross section is shown.

Reference numeral 1 denotes a rotating shaft, and 2, although not shown, is a casing of a rotary joint which is prevented from rotating.

The casing 2 is held relative to the shaft 1 via a bearing 3.

A seal 4 for cement slurry is fitted inside the bearing 3, and a seal 5 for preventing sludge from outside the machine from entering the bearing 3 is fitted and arranged on the outside.

A cement slurry transfer pipe 6 is attached to the casing 2, and connected to the transfer pipe 6, the casing 2 has a cement slurry introduction hole 7 and a circumferential introduction groove 8.

A cement slurry transfer hole 10 of the rotary shaft 1 is connected to the communication hole 9 so as to communicate with the circumferential groove 8 .

On the other hand, soft ground improvement equipment stirs sludge and injects concrete slurry into the area, but a method is being considered in which this concrete slurry is injected through the rotating hollow shaft of a stirrer. In this case, at the connection part between the concrete slurry transfer pipe 6 and the hollow shaft 1,
A rotary joint as described above is required.

This rotary joint needs to be placed in the middle of the rotating shaft and will penetrate into the rim drawer.

Further, since the cement slurry is not necessarily constantly being transferred, the differential pressure applied to the cement slurry seal 4 is large, resulting in severe load conditions.

Therefore, the life of the cement slurry seal 4 was short, which was the biggest problem when putting this system into practical use.

Therefore, an object of the present invention is to provide a rotary joint for transferring slurry, which has a longer seal life than the conventional gland packing type seal for cement slurry.

The features of this invention are: ■ The sealing members of the packing or U packing are placed in the rotary joint, and the seal members are combined with the backs of the seals facing each other, and the grease supply passages are placed on the side of the slurry side bearing, and the grease supply passages are placed oppositely. The seal member is placed in the opposing part, which is the middle of the arranged seal members, to reduce the differential pressure applied to the outermost seals on the cement slurry side and the bearing side, and to ensure that sufficient differential pressure is applied to the seal with grease. and improve seal life.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a sectional side view showing an embodiment of a rotary joint for transferring slurry according to the present invention, and FIG. 4 is a sectional side view showing a second embodiment.

In FIG. 3, the members indicated by numbers 1 to 4 and the members indicated by numbers 6 to 10 are the same as those of the prior art, and their explanations will be omitted.

The feature of the present invention lies in the sealing member 4, which will be explained below.

Grease supply pipes 11 and 12 are attached to the casing 2, and are connected to grease grooves 13 and 15, which will be described later.

21.22 is cement slurry m pieces V packing, 23.2
4 is the bearing side packing, which are arranged with their back faces facing each other.

25, 26, 27 are spacers, 28, 29 are spacers with grease supply holes, 13.15 are spacers 2 with grease supply holes.
Grease grooves 8 and 29, spacers 28 and 29 14 and 16
This is the grease supply hole.

Further, 17 is a packing retainer attached to the casing 2.

Next, its effects will be explained.

In Fig. 3, bearing attribute force P1, bearing supply oil pressure P
2. Middle part pressure P3, cement slurry side oil supply part pressure P
1. Cement l-slurry pressure is set to P5.

The grease supply pressure PG is made sufficiently higher than Pl to P5.

The grease supplied from the grease pipe 11 to the bearing side oil supply part flows out to the bearing part.

At this time ■ Pressure loss Δ when passing through the packings 21 and 23
If we consider that P is equal, we get the following.

P2=P1+ΔP, P4=P5+ΔP P3=max (P,, P5) Bearing portion attribute force P1 changes depending on external sludge pressure, and cement slurry pressure P5 changes greatly depending on working conditions.

Moreover, the durability is the most important problem, m pieces of cement slurry V.
The differential pressure applied to the gasket 21 is always ΔP.

In addition, in Fig. 3, the structure is such that there are bearings 3 on the top and bottom, but the bearing is on one side, and the outermost seal, for example, 2
Even if 3 comes into direct contact with the sludge, the differential pressure will be Δ
It becomes smaller with P.

According to this embodiment, it is possible to maintain constant the differential pressure applied to the seals 21, 22, or 23, 24 that come into contact with cement slurry or sludge, which is subject to the most severe conditions.
1, 22 or 23, 24 longer life can be achieved.

A second embodiment of the present invention will be explained with reference to FIG.

In Figure 4, the rotary joint casing 2
An example is shown in which the bearing 3 is supported on one side by a bearing 3 having a thrust portion (not shown).

Also, in this case, the packing 31, 32, 33° 34.3
5 uses U packing, and a dust seal 35 is used on the sludge side.

Even in such a case, the same effects as in the first embodiment can be achieved.

In short, according to the present invention, there is provided a casing in which a rotating shaft having a slurry passage therein is supported by a bearing, a slurry transfer pipe attached to the casing and connected to the slurry passage, and a gap between the casing and the rotating shaft. In a rotary joint for slurry transfer consisting of a sealing member fitted into a rotary joint, the sealing members are assembled with the back surfaces of the seals facing each other, and are arranged on the slurry side and the bearing side, and the grease supply path is arranged in the opposing part. This reduces the differential pressure applied to the outermost seal member (seal) on the slurry side and the bearing side, and ensures that sufficient differential pressure is applied to the greased seal, improving the seal life.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional rotary joint for transferring slurry, Fig. 2 is a sectional view taken along Fig. 1
The figure is a sectional side view showing a first embodiment of a rotary joint for transferring slurry according to the present invention, and FIG. 4 is a sectional side view showing a second embodiment. 1...Rotating shaft, 2...Casing, 3
...Bearing, 4...Slurry seal,
5...Bearing seal, 6...Slurry transfer pipe, 7...Cement slurry introduction hole, 8...
......Circumferential groove for introduction, 9...Communication hole, 10.
...Cement slurry transfer't, 11, 12...
... Grease supply piping, 13, 15... Grease groove, 14, 16... Grease supply hole, 21,
22...Cement slurry side ■Patzkin, 23
, 24... Bearing side ■Packskin, 25. 26.
27... Spacer, 28, 29...
Spacer with grease supply hole, Pl... Bearing force, P2... Bearing side oil supply part pressure P2゜P3...
...Middle part pressure, P4...Cement slurry side oil supply part pressure, P5...Cement slurry pressure, PG...Grease supply pressure.

Claims (1)

[Scope of utility model registration request] A casing in which a rotating shaft having a slurry passage formed therein is supported by a bearing, a slurry transfer pipe bonded to the casing and communicating with the slurry passage, and a sealing member fitted between the casing and the rotating shaft. A rotary joint for slurry transfer consisting of a rotary joint for transferring slurry, characterized in that the sealing members are assembled with the back surfaces of the seals facing each other, arranged on the slurry side and the bearing side, and a grease supply path is arranged on the opposing part. rotary joint.