JPH0711879A - Cutter-head bearing device for large-bore shield excavator - Google Patents

Abstract

PURPOSE:To enable transportation without division by reducing the bore of a bearing for a cutter head. CONSTITUTION:In a large-bore shield excavator, in which a cutter head 2 is installed rotatably in the front section of a shield body 1, a hollow shaft 5 having a diameter sufficiently smaller than the intermediate bearing beam 2c of the cutter head 2 is mounted at the center of the rear section of the cutter head 2. A bearing 7 receiving cutter-head torque shield thrust in the axial direction of the hollow shaft 5 and a bearing 8 receiving cutter eccentric moment are set up. A driving means driving a central cutter head 2b, an agitator 18, etc., rotatably bears the shield body 1 while being installed into the hollow shaft 5. Accordingly, division is unnecessitated by the reduction of the bores of the bearings 7, 8, thus easily conducting transport and assembly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-diameter shield machine having an improved cutter head support structure.

[0002]

2. Description of the Related Art Conventionally, in a large-diameter shield machine having a diameter of 10 m or more, a rotatable cutter head b is supported by a large-diameter roller bearing c on the front part of a shield body a as shown in FIG. . In such a shield machine, when it is transported on land or assembled on site, it is limited in size and weight, so conventionally it is divided into a plurality of parts in advance to facilitate transportation and assembly (for example, Japanese Utility Model Publication No. 3-32692).

[0003]

However, when the large-diameter roller bearing c is divided, the number of welding and machining portions increases, so that the number of manufacturing and assembling steps increases, which leads to an increase in cost, and in comparison with the integrated type. Since the accuracy after assembly tends to be low, there were problems such as shortening the life.
The present invention has been made in order to improve the conventional problems, and an object thereof is to provide a large-diameter shield machine which is easy to manufacture, transport and assemble.

[0004]

In order to achieve the above object, the present invention provides a large-diameter shield excavator in which a cutter head is rotatably provided in a front portion of a shield body, in which the cutter head is provided at the center of the rear portion of the cutter head. A hollow shaft having a diameter sufficiently smaller than that of the intermediate support beam of the head is provided, and the hollow shaft is rotatably supported by the shield body via bearings provided in a plurality of front and rear stages. A drive means for driving an agitator or the like is provided.

[0005]

With the above construction, the cutter head can be rotatably supported by mounting two kinds of bearings having different diameters, so that the cutter head can be transported and assembled without dividing the bearing, and the cutter head supporting portion can be manufactured and manufactured. It will be easy to assemble and transport.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. In these figures, 1 is a shield body of a large-diameter shield machine, and a cutter head 2 is provided at the front part.
Is rotatably provided. The cutter head 2 is
Spokes 2a are formed on the front surface in a radial direction, and a large number of cutters 3 for excavating a face are attached to both sides of these spokes 2a and a cone-shaped central cutter head 2b provided at the center of the front surface. On the rear surface of the cutter head 2, a plurality of intermediate support beams 2c are projected on the same circumference, and a support beam mounting disk 4 having a circular hole 4a in the central portion is fixed to these intermediate support beams 2c. ing.

The support beam mounting disk 4 is provided so as to close the front end side opening of the outer ring 1b provided on the partition wall 1a of the shield body 1. The shield body 1
The partition wall 1a is provided so as to close the front side opening of the shield body 1, the outer ring 1b is provided in the central portion, and the inner ring 1c is provided inside thereof in a liquid-tight manner. A hollow shaft 5 is provided at the center of the. The hollow shaft 5 has a tubular shape having a diameter sufficiently smaller than that of the cutter head 2, a front end thereof is fixed to the rear surface of the support beam mounting disk 4, and an opening on the rear end side is closed by an end plate 5a.

The outer peripheral portion of the hollow shaft 5 and the inner ring 1 are
Two bearings 7, 8 that rotatably support the cutter head 2 are provided in the bearing case 9 between the inner peripheral portion of c so as to be spaced apart in the front-rear direction. These bearings 7, 8
Is formed of a roller bearing, and the bearing 7 provided in the front stage supports the thrust force acting on the hollow shaft 5 and the rotating torque of the cutter head 2, and the bearing 8 provided in the rear stage is the bearing 7 in the front stage. It has a smaller diameter and supports an eccentric moment acting on the cutter head 2.

A ring gear 1 is provided at the rear end of the hollow shaft 5.
The pinion 12 attached to the rotary shaft 11a of the cutter head drive motor 11 is meshed with the ring gear 10. The cutter head drive motor 11 is composed of a plurality of reduction motors and is attached to the inner ring 1c of the shield body 1. The cutter head drive motor 11 drives the cutter head 2 to rotate about the hollow shaft 5. It has become so.

On the other hand, a rotary shaft 14 is provided at the center of the cutter head 2, and the central cutter head 2b is fixed to the front end of the rotary shaft 14. A hollow rotary shaft 15 is rotatably fitted in an intermediate portion of the rotary shaft 14, and the hollow rotary shaft 15 is attached to a support member 16 fixed to the front surface of the support beam mounting disk 4 by a bearing 1.
It is rotatably supported via 7. The hollow rotary shaft 15 has a front end projecting in the bulkhead 2d,
An agitator 18 is attached to the front end.

Further, the rear ends of the rotary shaft 15 and the hollow rotary shaft 16 are connected to a plurality of hydraulic motors 20 via a speed reducer 19 provided in the hollow shaft 5. The speed reducer 19
Has reduction gears 19a and 19b having different reduction ratios, and the rotary shaft 15 is provided via these reduction gears 19a and 19b.
Further, the hollow rotary shaft 16 is connected to the hydraulic motor 20, and the central cutter head 2b and the agitator 18 are normally and reversely rotated by the hydraulic motor 20 at different rotational speeds. Reference numeral 22 in the drawing denotes a rotary joint that relays the hydraulic pressure supplied to each hydraulic motor 20, and reference numeral 23 denotes a seal that prevents dirt and muddy water in the cutter head 2 from entering the shield body 1 side.

Next, the operation will be described. While the cutter head 2 is rotated by the cutter head drive motor 11, the shield body 1 is propelled into the ground to excavate, and the earth and sand excavated by the cutter 3 of the cutter head 2 is removed. , And is taken into the bulkhead 2d from the earth and sand intake (not shown) opened between the spokes 2a. The mud water is injected into the bulkhead 2d by the mud pipe 25, and the earth and sand taken into the bulkhead 2d is agitated with the mud water by the agitator 18 rotated by the hydraulic motor 20 to be slurried and discharged. The pipe 26 discharges backward from inside the cutter head 2 through the inside of the shield body 1.

A hydraulic motor 20 which is the same as the agitator 18
The central cutter head 2b which is rotated by is rotated by a speed reducer 19 with a torque and a rotational speed different from those of the agitator 18, and excavates the face blade near the center left by the cutter 3 attached to the spokes 2a of the cutter head 2. Like

[0014]

As described in detail above, according to the present invention, the hollow shaft for rotatably supporting the cutter head has a diameter sufficiently smaller than the diameter of the cutter head, and the hollow shaft is provided with a plurality of bearings arranged in front and back. Since the bearing is supported by the shield body, it is possible to transport and assemble without dividing the bearing. This eliminates the need for processing and assembling work for joining the divided parts, which can significantly reduce the manufacturing cost and improve the assembling accuracy, thus extending the life of the bearing.

Further, since a central cutter head, a drive mechanism for driving an agitator, an injection device for injecting a drug into a face, a manhole for entering and inspecting the cutter head, etc. can be installed in the hollow shaft, these are installed. It is possible to effectively use the inside of the shield body without needing a space for the inside of the shield body.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional large-diameter shield machine.

FIG. 2 is a sectional view of a large-diameter shield machine according to an embodiment of the present invention.

FIG. 3 is an enlarged view showing a main part of a large-diameter shield machine according to an embodiment of the present invention.

[Explanation of symbols]

 1 Shield body 2 Cutter head 2b Central cutter head 5 Hollow shaft 7 Bearing 8 Bearing 18 Agitator

Claims (1)

[Claims] 1. A cutter head 2 at the front of a shield body 1.
In a large-diameter shield machine with rotatably provided, a hollow shaft 5 having a diameter sufficiently smaller than the intermediate support beam 2c of the cutter head 2 is provided at the center of the rear part of the cutter head 2 in the axial direction of the hollow shaft 5. A cutter head bearing device for a large-diameter shield machine, wherein a bearing 7 for receiving a cutter head torque shield thrust and a bearing 8 for receiving a cutter eccentric moment are provided so as to be rotatably supported on the shield body 1.