JP2001082078A - Disk cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk cutter preventing the occurrence of the thrust component force from a bearing on the inner periphery side, reducing the load of a bearing on the outer periphery side, and capable of maximizing the whole bearing load capacity. SOLUTION: A support shaft 4 is inclinatorily supported against a drilled face by an outside retainer 2 and an inside retainer 3, and a tapered cutter ring 9 is rotatably supported on the support shaft 4 via bearings. The bearings are constituted of a conical roller bearing 6 arranged on the large diameter side of the cutter ring 9, a cylindrical roller bearing 7 arranged on the small diameter side, and a thrust bearing 8 arranged between both bearings 6, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cutter particularly suitable for a small-diameter thruster.

[0002]

2. Description of the Related Art Conventionally, in a taper-shaped disk cutter (taper cutter) used particularly in a small-diameter thruster, it is necessary to secure a digging diameter through which the thruster passes with a small number of cutters. The blade has a shape that greatly protrudes outward. Also, in this type of disk cutter, in order to prevent earth and sand or water from entering the sliding surface between the support shaft and the cutter ring,
It is necessary to adopt a structure in which a seal member is inserted between the outer retainer and the cutter ring and between the inner retainer and the cutter ring. Therefore, a bearing that supports the cutter ring is disposed inside the seal members. I have to adopt a structure. For this reason, the load point on the cutter comes outside the support point, and a large load is applied particularly to the bearing arranged on the outer peripheral side. For this reason, the outer-peripheral bearing is more likely to be damaged in spite of a larger load capacity than the inner-peripheral bearing.

FIG. 2 shows an example of a conventional disk cutter.
Are known. In the conventional disk cutter 50, an outer retainer 51 and an inner retainer 52 support the support shaft 53 at an angle with respect to the excavation surface. Roller bearings (tapered roller bearings)
54 are inclined, and a relatively small tapered roller bearing 55 is inclined on the inner peripheral side (lower side in the figure).
Is rotatably supported. The cutting 56
A number of bit chips 57 are embedded in the outer peripheral surface of the chip. The outer peripheral surface of the outer retainer 51 and the cutter 5
6, seal members 58 and 59 are interposed between the outer peripheral surface of the inner retainer 52 and the inner peripheral surface of the cutter ring 56, respectively.

Another conventional example has a structure shown in FIG. In the conventional disk cutter 60, the support shaft 63 is inclined and supported with respect to the excavation surface by the outer retainer 61 and the inner retainer 62.
3, a cylindrical roller bearing 64 and a thrust bearing 65 are disposed on the outer peripheral side, and a similar cylindrical roller bearing 66 and a thrust bearing 67 are disposed on the inner peripheral side.
5; 66, 67, the cutter ring 68 is rotatably supported. A number of bit chips 69 are buried on the outer peripheral surface of the cutting 68. In addition, between the outer peripheral surface of the outer retainer 61 and the inner peripheral surface of the cutter ring 68 and between the outer peripheral surface of the inner retainer 62 and the cutter ring 68.
Seal members 70 and 71 are interposed between the inner peripheral surface and the inner peripheral surface, respectively.

[0005]

However, in the first conventional example shown in FIG. 2, when the cutter ring 56 receives a radial load, the tapered roller bearing 55 on the inner peripheral side particularly has Since the tapered roller ring 55 is inclined in the opposite direction to the taper direction, a thrust component force is generated in the tapered roller bearing 55 in a direction toward the outer peripheral side, and the load applied to the tapered roller bearing 54 on the outer peripheral side is generated by the thrust component force. Is further increased, and the tapered roller bearing 54 on the outer peripheral side is used under more severe conditions. Also,
In the first conventional example, when the outer ring portion of the bearing is abolished in order to mount a tapered roller bearing having a large load capacity,
The rolling surface (cutting 56) of the tapered roller bearing 54 on the large diameter side
Of the cutter ring 56 is substantially parallel to the outer diameter surface of the cutter ring 56, and the thickness of the cutter ring can be sufficiently increased. There is a problem that only a bearing having a small capacity can be used to secure the thickness of the cutter because it is greatly inclined with respect to the radial surface.

On the other hand, in the second conventional example shown in FIG. 3, two types of cylindrical roller bearings 64 and 66 and thrust bearings 65 and 67 are provided on the outer peripheral side and the inner peripheral side, respectively.
Since it is composed of a combination of individual bearings, a large space is required as a bearing arrangement space, and when these bearings are to be arranged in a limited space,
There is a problem that the load capacity is limited.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and eliminates the generation of a thrust component from the inner peripheral bearing to reduce the load on the outer peripheral bearing. It is an object of the present invention to provide a disk cutter capable of maximizing the bearing load capacity of the disk cutter.

[0008]

In order to achieve the above object, a disk cutter according to the present invention comprises:
A tapered cutter ring is rotatably supported via a bearing on a support shaft which is inclined and supported with respect to the excavation surface by the outer retainer and the inner retainer. In a disk cutter having a seal member interposed therebetween, the bearing may be a tapered roller bearing disposed on a large diameter side of the cutter ring, or a cylindrical roller bearing disposed on a small diameter side of the cutter ring. And a thrust bearing disposed between the bearings.

According to the disk cutter of the present invention, the inner peripheral bearing is a combination of a cylindrical roller bearing receiving a radial load and a thrust bearing receiving a thrust load. No thrust component is generated, and the load on the bearing on the outer peripheral side can be reduced as compared with the conventional example shown in FIG.
Further, since the inner peripheral side is a cylindrical roller bearing, even if the outer race portion (outer race) of the bearing is eliminated, a large roller can be inserted to increase the load capacity. According to the disk cutter of the present invention, FIG.
Since the bearing on the outer peripheral side can be a single bearing as compared with the conventional example shown in FIG. 1, large load rollers can be inserted on the outer peripheral side to increase the load capacity. Thus, an effective bearing arrangement having the largest load capacity as a whole can be obtained in a limited space by using a bearing having the same load capacity as the conventional one.

[0010]

Next, a specific embodiment of a disk cutter according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a disk cutter according to an embodiment of the present invention.

The disk cutter 1 of this embodiment is used by being mounted on a cutter head (not shown) of a small-diameter thruster. In the disc cutter 1, a support shaft 4 is fixed to an outer retainer 2 and an inner retainer 3 by being inclinedly supported by a bolt 5 with respect to an excavation surface. The support shaft 4 and the outer retainer 2 are fixed by welding. A tapered roller bearing (tapered roller bearing) 6 is arranged on the outer peripheral side (upper side in the figure) of the support shaft 4 so as to be inclined in the same direction as a taper direction of a cutter ring 9 described later, and is arranged on the innermost peripheral side (see FIG. A cylindrical roller bearing 7 is disposed on the lower side (the lower side), and a thrust bearing 8 is disposed between the bearings 6 and 7. Here, the outer ring portion (outer race) of the cylindrical roller bearing 7 is abolished, and a larger roller can be mounted accordingly.

The tapered roller bearing 6 and the cylindrical roller bearing 7
A cutting ring 9 is rotatably supported on an outer peripheral portion of the cutting ring 9. A number of bit chips 10 are buried in the outer peripheral surface of the cutter ring 9, and when the cutter head rotates, the outer peripheral surface of the cutter ring 9 rotates around the support shaft 4 while contacting the face. The face is excavated by the bit tip 10 on the outer peripheral surface of the cutter ring 9.

A seal member 11 is interposed between the outer peripheral surface of the outer retainer 2 and the inner peripheral surface of the cutter ring 9 outside the tapered roller bearing 6. A seal member 12 is interposed between the outer peripheral surface of the inner retainer 3 and the inner peripheral surface of the cutter ring 9. These seal members 11 and 12 prevent excavated earth and sand, water, and the like from entering the bearing sliding contact surface.

In the conventional example shown in FIG. 2,
The radial load applied to the cutter ring 56 causes a thrust component in the direction toward the outer periphery to the tapered roller bearing 55 on the inner periphery. However, in the disk cutter 1 of the present embodiment, the inner peripheral bearing is Since the cylindrical roller bearing 7 and the thrust bearing 8 are combined, no thrust component is generated from the inner peripheral bearing. Therefore, the load applied to the tapered roller bearing 6 on the outer peripheral side can be reduced. Further, in the conventional example shown in FIG. 3, two bearings of a cylindrical roller bearing 64 and a thrust bearing 65 are arranged on the outer peripheral side, and there is a problem of securing a space for disposing the bearings. On the other hand, in the disk cutter 1 of the present embodiment, since the outer peripheral side bearing can be one tapered roller bearing 6, a large roller can be inserted into the outer peripheral side to increase the load capacity. There is an advantage.

Next, in order to confirm the effect of the disk cutter 1 according to the present embodiment, the load (thrust) applied to each bearing when a predetermined load is applied to the outermost periphery, the center and the innermost periphery of the cutter ring 9 respectively. Load and radial load) were calculated, and the safety factor for the rated load of the bearing was calculated. Table 1 shows the result of this calculation. In Table 1, as a comparative example, the disk cutter 5 according to each conventional example (Comparative Example 1 and Comparative Example 2) shown in FIGS.
The results of similar calculations performed on 0 and 60 are also shown. Here, the tapered roller bearing 6 of this embodiment and the tapered roller bearing 54 of Comparative Example 1 (FIG. 2) use the same load capacity bearing, and similarly, the thrust bearing 8 of this embodiment and Comparative Example 2 ( The thrust bearing 67 in FIG. 3), the cylindrical roller bearing 7 in this embodiment, and the cylindrical roller bearing 66 in Comparative Example 2 use the same load capacity.

[0017]

[Table 1]

From these calculation results, it can be said that the bearing with the lowest safety factor (marked with *) is the most susceptible to damage under each load condition. It is clear that the value of the minimum safety factor is larger than those of Comparative Examples 1 and 2 below, and it can be seen that it is most difficult to break.

As described above, the disk cutter 1 of the present embodiment
Can maximize the load capacity of the bearing, and particularly, to increase the load capacity of the outer peripheral bearing (tapered roller bearing 6), which is the most severe load condition in this type of disk cutter. Thus, the bearing life can be greatly improved.

In the present embodiment, a cutter ring 9 having a substantially tapered shape so that the outer peripheral surface becomes gradually smaller along the axial direction of the support shaft 4 is used. Although a disk cutter having a configuration in which a plurality of bit chips 10 are embedded has been described, the present invention is not limited to such a chip-type disk cutter. That is, as a structure of the cutter, for example, a plurality of blades having a substantially tapered shape as a whole such that the diameter of the blades gradually decreases along the axial direction of the support shaft, or a large diameter A gear-shaped blade portion and a small-diameter gear-shaped blade portion having a generally tapered shape so that the diameter of the blade edge of the blade portion gradually decreases along the axial direction of the support shaft. Alternatively, a substantially tapered cutter having a plurality of spiral blades may be used.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disk cutter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional disk cutter.

FIG. 3 is a cross-sectional view showing another example of a conventional disk cutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc cutter 2 Outer retainer 3 Inner retainer 4 Support shaft 5 Bolt 6 Tapered roller bearing 7 Cylindrical roller bearing 8 Thrust bearing 9 Cutting 10 Bit chip 11, 12 Seal member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichiro Okuyama 5 Yokaichi-cho, Komatsu-shi, Ishikawa Pref.

Claims (1)

[Claims] A tapered cutter ring is rotatably supported via a bearing on a support shaft which is inclined and supported with respect to an excavation surface by an outer retainer and an inner retainer, and is provided between the outer retainer and the cutter ring. In a disk cutter in which a seal member is inserted between an inner retainer and a cutter ring, the bearing includes a tapered roller bearing disposed on a large diameter side of the cutter ring, and a cylindrical roller disposed on a small diameter side of the cutter ring. A disk cutter comprising a bearing and a thrust bearing disposed between the two bearings.