Fully-electrically driven downhole safety valve

A fully-electrically driven downhole safety valve, comprising:

• a downhole safety valve mechanism and a downhole safety valve control system;
• wherein the downhole safety valve mechanism includes an electronic cabin module, a transmission control module, a motion conversion module, a magnetic coupling and spring module, and a valve module;
• the transmission control module includes an outer pressure-bearing cylinder, a high-torque DC motor, a single-pass stud, a motor mounting plate, a low-speed gear, a mounting bushing, a hollow gear shaft, an electromagnetic clutch, a transmission housing, a plug-in mounting pad, an electromagnetic brake, an electromagnetic brake braking pad, a connecting flange and a hollow transmission shaft;
• the high-torque DC motor is mounted on an annular motor mounting plate by screws, the low-speed gear is mounted on the high-torque DC motor in a flat key fit, the motor mounting plate is mounted on the mounting bushing by the single-pass stud, the mounting bushing is mounted on the transmission housing through an interference fit, a bearing is mounted on the mounting bushing, the hollow gear shaft is mounted on the mounting bushing through the bearing and an upper gear meshes with the low-speed gear, a lower end of the hollow gear shaft is mounted on the electromagnetic clutch through interference bonding, the electromagnetic clutch is mounted on the transmission housing through interference bonding, a lower end of the electromagnetic clutch is mounted on the hollow transmission shaft through interference bonding, an annular connecting flange is mounted on the hollow transmission shaft through a pin shaft, the connecting flange and an annular electromagnetic brake braking pad are fixed by bolts, the electromagnetic brake is fixed on the transmission housing with the plug-in mounting pad through screws, and the hollow transmission shaft forms a bearing fit with the transmission housing through the bearing;
• the motion conversion module includes a torque limiter, an upper bearing joint, an inner pressure-bearing cylinder, thin-walled bearings, a screw mounting cylinder, an embedded ball screw slider, an embedded ball screw and a lower bearing joint;
• the torque limiter is mounted in the embedded ball screw through screws, the embedded ball screw forms a bearing fit with the screw mounting cylinder through two thin-walled bearings, the embedded ball screw forms a threaded pair fit with the embedded ball screw slider and the embedded ball screw slider is located inside the embedded ball screw, and a spline groove formed in the embedded ball screw slider and a spline shaft on the inner pressure-bearing cylinder form a spline fit;
• the magnetic coupling and spring module includes an outer magnetically coupled cylinder, a flow pipe cap, outer magnetic rings, outer gaskets, inner magnetic rings, inner gaskets, an inner magnetically coupled flow pipe and a spring;
• the outer magnetically coupled cylinder is molded by welding two rings and a cylinder, the outer magnetic rings and the outer gaskets are disposed inside the outer magnetically coupled cylinder, one outer magnetic ring and several outer gaskets constitute one outer magnetically coupled unit, several outer magnetically coupled units constitute an outer magnetically coupled device, the inner magnetic rings and inner gaskets of the same numbers as the outer magnetic rings and outer gaskets inside the outer magnetically coupled cylinder are mounted on the inner magnetically coupled flow pipe, the outer and inner magnetic rings and the outer and inner gaskets are in one-to-one correspondence, the inner and outer magnetic rings have the same or different magnetic poles and constitute an inner magnetically coupled device;
• the flow pipe cap is mounted on a top end of the inner magnetically coupled flow pipe by screw-threads, and annular rings protruding from upper and lower portions of the outer magnetically coupled cylinder form a clearance fit with the inner pressure-bearing cylinder;
• the flow pipe cap and the inner magnetically coupled flow pipe form a clearance fit with the inner pressure-bearing cylinder, and the spring is disposed at a lower end of the outer magnetically coupled cylinder;
• the downhole safety valve control system includes a downhole comprehensive unit and an uphole comprehensive unit, which are connected by a power line;
• wherein the downhole comprehensive unit includes an information receiving module, a motor relay, an electromagnetic clutch relay, an electromagnetic brake relay, a downhole control and information processing module, a downhole power carrier module, and a power receiving module;
• the motor relay is connected to the high-torque DC motor and the downhole control and information processing module through cables, respectively;
• the electromagnetic clutch relay is connected to the electromagnetic clutch and the downhole control and information processing module through cables, respectively;
• the electromagnetic brake relay is connected to the electromagnetic brake and the downhole control and information processing module through cables, respectively;
• and the uphole comprehensive unit includes an uphole power carrier module, an uphole control and information processing module, a power transmission module, and a status display module.