REVOLVING GEAR DRIVE MECHANISM OF JACKING AND PULLING DEVICE FOR STEEL PIPE CASING

摘要

PROBLEM TO BE SOLVED: To obtain a strong torque in compliance with a steel pipe casing P when there is a foreign material in the ground or the rotary resistance of the casing increases due to the pressure of the natural ground when suspending the work.;SOLUTION: A right frame 110 and a left frame 120 are connected to each other so as to define a central opening surounding the steel pipe casing P to form a base frame 100, and a rise and fall frame 200 having a divided structure is disposed on the base frame 100 through a rise and fall jack 300. Hydraulic motors 800 whose speed can be variably changed over are provided in the vicinity of the four corners of the rise and fall frame 200. Hydraulic pressure is sent from a pilot port A833 of the hydraulic motor 800 according to the rotary resistance of the steel pipe casing P to change over the operation mode. The driving gear 450 equipped on the rotary spindle 810 of the hydraulic motor 800 meshes with spur wheel of the revolving gear 500. The revolving gear 500 is supported by the upper plates 215, 225 and the lower plates 216, 226 of the rise and fall frame 200 in the upper slide mechanism 540 and the lower slide mechanism 570 provided with slide shoes 545, 575 and vertically moved in accordance with the vertical movement of the rise and fall frame 200.;COPYRIGHT: (C)2002,JPO