High-speed large-torque full-hydraulic top drive well-drilling device

The invention discloses a high-speed large-torque full-hydraulic top drive well-drilling device which is driven by a group of high-speed small-torque hydraulic motors. Each hydraulic motor is equipped with an independent multi-piece disk brake and a planetary speed reducer; a main shaft can rotate at high speed and large torque; a disk brake is not required to be arranged. The structure of the high-speed large-torque full-hydraulic top drive well-drilling device comprises a lifting device, a main transmission box, a rotation head assembly, a hydraulic chuck and an opening-closing sliding trolley which are arranged from top to bottom, wherein the upper part of the lifting device is directly connected with a traveling trolley by virtue of a lifting cross beam; the lower part of the lifting device is connected with a lifting seat of the main transmission box; the rotation head takes a rotation driver driven by a worm as a main working part; the accurate angle location is implemented by electric-hydraulic proportional closed-loop control; the rotation head has self-locking property and can be used for simultaneously driving a drilling column to rotate with the main shaft; the low-speed torque increasing operation can be implemented. The hydraulic top driver is small in size and light in weight; electric-hydraulic proportional volumetric speed control in a high rotation speed range is implemented by a hydraulic system through a mechanical and electrical integration technology, thereby meeting the requirements of a plurality of deep well drilling processes and drilling disciplines, especially core drilling during continental scientific drilling of deep wells.