| 摘要 |
<p>PURPOSE:To miniaturize a main bearing by setting a cutter head slidably in the front and rear with a hydraulic cylinder, and by setting the energizing hydraulic pressure of the cylinder to be equal to or lower than the load capacity of the main bearing for supporting the cutter head. CONSTITUTION:In front of a shield main-body 1, a cutter head 2 is set via a slide member 7 provided with a main bearing 6, a slide cylinder 8, and a cutter head driving motor 11. Besides, by the cylinder 8, the cutter head is set slidably in the front and rear, and under working, hydraulic pressure is always fed to, and the head is energized so that the pressure may come to a value equal to or less than the allowance value of the transmittable propelling force of the main bearing 6. When an overload is applied to the head 2, then the head 2 is moved backward, so that the overload is not applied to the bearing 6. As a result, the bearing 6 can be miniaturized, and a cutter head bearing device which is easily transported can be obtained.</p> |
