JPS624619Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a shaft seal device for a shield tunnel boring machine used in a slurry shield construction method.

FIG. 1 shows an outline of the shield type tunnel excavator, in which 1 is the shield body, 2 is the cutter face at the tip of the excavation rotating shaft, 3 is the bearing of the same rotating shaft, 4 is the gear attached to the rear end of the same rotating shaft, 5 is a drive gear of a drive motor 6 that meshes with the same gear 4, 7 is an agitator, 8 is a shield jack, 9 is a water pipe, and 10 is a drain pipe. In order to prevent the face from collapsing and maintain its integrity, Water is supplied from the water pipe 9 at a pressure higher than the face pressure, and is stirred so that the water excavated by the agitator 7 does not settle at the lower part of the face.

FIG. 2 shows a conventional agitator. Reference numeral 11 is a drive motor whose rotation is transmitted to an agitator shaft 15 via a coupling 12 and keys 13 and 14. A key 16 is attached to the tip of the agitator shaft 15. An agitator blade 17 is attached via the agitator blade 17. Reference numeral 18 denotes a retaining plate for the agitator blade 17, which is fixed to the agitator shaft 15 with bolts or the like. 19
is the bearing housing, 20 is the bearing, 2
1 is connected to the bearing housing 1 via the bolt 22
9 is a bearing holder attached, 23 is an oil seal that prevents lubricating oil from leaking into the bearing, 24 is a bearing mounting nut, 25 is an O-ring, 26 is a bearing collar, 27 is a seal, and 28 is a bearing. This is a bolt that attaches the housing 19 to the shield body 1.

Therefore, the seal 27 has a mud water pressure of several kg/cm ² and must seal mud water mixed with earth and sand under very poor conditions. In order to cope with this, the surface hardness of the agitator shaft 15 is increased and furthermore, hard chrome plating is applied. Also seal 2
7 is provided in multiple stages, between which oil is supplied as shown in a and b to reduce the sliding resistance of the seal 27 and the relative sealing pressure of the seal.

However, recently there has been a demand for improvements in the agitation ability of the agitator, and as the agitator shaft rotates at higher speeds, the life of the seal has become shorter, and seal failures have sometimes occurred during the course of a single construction job. Replacing the agitator requires injecting chemicals for ground improvement into the face to prevent it from collapsing, resulting in large losses.

In addition, as a result of investigating conventional products that had problems, it was found that the agitator shaft, which is extremely hard, was considerably worn at the edges of the seal, and in many cases, the seal material itself was not worn out.

This proposal was proposed in view of these circumstances, and the agitator shaft is watertightly supported through multiple stages of seals arranged in the bearing housing in the axial direction. The end shoulder portion of the bearing sleeve, which is supported so as to be relatively immovable and relatively rotatable, is clamped between a plurality of slide shims and a pressing member that abut against the end surface of the bearing housing and are divided in the circumferential direction. , relates to a shaft sealing device for a shield type tunnel excavator, characterized in that the holding member and the shoulder portion of the bearing sleeve are fastened to the bearing housing, and its purpose is to have a simple configuration. An object of the present invention is to provide an improved shaft sealing device that dramatically improves the life of the agitator shaft of a shield type tunnel excavator.

In this case, as described above, the agitator shaft, which is watertightly supported through multiple stages of seals arranged in the bearing housing in the axial direction, is made immovable in the axial direction and capable of relative rotation through the bearing. A shoulder at the end of the bearing sleeve to be supported is held between a slide shim and a presser member that are brought into contact with the same surface at the end face of the bearing housing, and the presser member and the shoulder are fastened to the end face of the bearing housing. In addition, by configuring the slide shim from a plurality of parts divided in the circumferential direction, if a malfunction occurs in the sealing device of the agitator shaft, loosening the tightening of the presser member against the bearing housing will cause damage to both members. Since the slide shim interposed between them is formed into an arc shape divided in the circumferential direction, it can be easily removed from both of the above-mentioned members, and thus the bearing sleeve is separated from the slide shim along with the bearing and the agitator shaft. By moving the presser member forward by the thickness and tightening it again to the bearing housing, thus moving the contact surface of the agitator shaft with the seal, and bringing the unworn part of the agitator shaft into new contact with the seal, The life of the sealing device of the present invention can be dramatically increased compared to conventional sealing devices.

The present invention will be described below with reference to the illustrated embodiments.

In FIG. 3, reference numeral 11 denotes an agitator shaft drive motor, which is fixed to a bearing housing 19 with bolts or the like, and its rotation is transmitted to the agitator shaft 15 via a coupling 12 and keys 13 and 14. A key 16 is attached to the tip of the agitator shaft 15.
Agitator blades 17 are attached to the agitator shaft 15 via bolts, and a retaining plate 18 is fixed to the agitator shaft 15 via bolts.

21 is a bearing sleeve that supports the agitator shaft 15 so as to be relatively immovable in the axial direction and relatively rotatable via the bearing 20 that bears the radial load and the thrust load, and the bearing collar 26;
A slide shim 31 whose end shoulder abuts against the end face of the bearing housing 19 and a bearing retainer 2
1, and the bearing holder 21 and the shoulder portion are fastened to the bearing housing 19 via bolts 22. In the figure, 24 is a bearing mounting nut, and 30 is a bolt that connects the bearing sleeve 21 and the bearing retainer 21.

The slide shim 31 is composed of a plurality of arcuate pieces divided in the circumferential direction as shown in FIG. The bolt hole 31a into which the bolt 22 is to be inserted is cut out so that it can be disassembled in the circumferential direction.

23 is an oil seal, and 25 and 32 are O-rings that serve as a seal for lubricating oil of the bearing. Seals 27 are attached to the bearing housing 19 and are arranged in several stages to seal muddy water mixed with several kg/cm ² of earth and sand on the face side. Others 28 are bolts for attaching the bearing housing 19 to the shield body 1.

Therefore, when the agitator shaft 15 rotates and the agitator blade 17 at its tip agitates the muddy water in front of the face to prevent sedimentation, the agitator shaft 15 is rotated by the seal 27 as shown in FIG. However, even if the hardness of the surface of the agitator shaft 15 is increased to a certain extent, the surface of the agitator shaft 15 remains sealed 27 as shown in FIG.
The contact force of the tip of the lip with the surface of the agitator shaft 15 is reduced, and the sealing effect of the lip of the seal 27 is deteriorated.

In the illustrated embodiment, in preparation for such a case, a slide shim 31 having the same thickness as the amount by which the agitator shaft 15 is to be slid is incorporated, and the sealing device of the agitator shaft 15 is installed slightly before the end of its life. , remove the agitator shaft drive motor 11,
Loosen the bolt 22 slightly to the extent that the slide shim 31 can be removed. At this time, since face pressure is acting,
It is dangerous to remove all the bolts 22 from the bearing housing 19.

When the slide shim 31 is removed from between the bearing housing 19, the bearing sleeve 29, and the bearing holder 21, and then the bolt 22 is tightened again, the agitator shaft 15 is removed by the thickness of the slide shim 31, as shown in FIG.
As the seal 27 advances, the lip of the seal 27 presses against the non-wearing portion of the agitator shaft 15, thereby restoring the sealing system to the same one as the new sealing system.

As shown in FIG. 6, the agitator shaft 15 only has to be slid within the range 1 between adjacent seals 27, 27 by the wear range of the agitator shaft 15 each time. , 27 can be slid several times within the range l, and in this case, as the agitator shaft 15 slides, the coaxial shaft 15 is
Increase the number of slide shims 31 that have a thickness equivalent to the amount of slides once, or use one slide shim 31 that has a thickness that is the sum of the thickness that corresponds to the amount of slides once. It is something to do.

According to the present invention, in a shield type tunnel excavator, the sealing device of the agitator shaft can be removed by simply removing the slide shim without taking measures to prevent collapse, such as injecting chemicals into the face while applying mud water pressure. can be restored.

[Brief explanation of the drawing]

Fig. 1 is a vertical side view showing an outline of a shield type tunnel excavation machine, Fig. 2 is a longitudinal side view of a shaft sealing device of a conventional shield type tunnel excavation machine, and Fig. 3 is a longitudinal side view of a shield type tunnel excavation machine according to the present invention. FIG. 4 is a front view of the slide shim mounting portion, and FIGS. 5 to 7 are explanatory diagrams of the operation of the present invention. 15... Agitator shaft, 19... Bearing housing, 21... Bearing holder, 22... Bolt, 27... Seal, 31... Slide shim.

Claims (1)

[Scope of utility model registration request] The agitator shaft, which is watertightly supported through multiple stages of seals arranged in the bearing housing in the axial direction, cannot be moved relative to the bearing in the axial direction.
The end shoulder portion of the bearing sleeve, which is supported so as to be relatively rotatable, is clamped between a plurality of slide shims that abut against the end surface of the bearing housing and are divided in the circumferential direction and an end holding member of the bearing housing. A shaft sealing device for a shield type tunnel excavator, characterized in that the holding member and the shoulder portion of the bearing sleeve are fastened to the bearing housing.