Electric wrench is assembly screws, bolts and mechanical construction tools, with functions of automatic control of torque. Widely used in bridge plug welding structure construction, factory building, the tower and the installation of chemical industry, metallurgy, power generation equipment. Large machinery, lifting equipment and vehicle assembly, as well as to the torque and axial tension of threaded fasteners have strict requirements of occasions. Below small make up to introduce the common structure form electric wrench. Electric wrench has safety clutch type and impact type two kinds of structure. Safety clutch type is a kind of using when they reach a certain moment trip safety clutch mechanism, to complete the installation of thread structure; Impingement is USES the impact mechanism, with its impact torque screws, the structural type of finish. The former because of its simple structure, output torque is small, and there is a certain reaction moment, usually only suitable for the manufacture of Mmm and under electric wrench; Which structure is relatively complex, high manufacturing process requirement, but the output torque, and reaction moment is very small, generally suitable for large size electric wrench. Impact type electric wrench by motor, planetary gear reducer, ball screw groove impact mechanism, and turn the power switch, the power supply connection device and motor sleeve, etc. Impact type electric wrench according to choose the type of the motor is single-phase series electric wrench and three-phase electric wrench. Single-phase series motor for electric wrench device inside the plastic shell. Plastic shell is used for supporting the structure of the motor, and the additional motor stator insulation. Because of the impact type electric wrench in assembly or remove the screw thread, gear motor, plastic shell of ball screw groove end face gear planetary gear reducer and impact mechanism between the plastic cover before there is a large axial tension, and the planetary gear reducer requires a high assembly accuracy, so on the seam allowance of plastic shell, bearing housing and screw thread connection place all set metal insert, in order to enhance the shell of the rigid, improve the machining precision of the plastic shell and the ability to connection place under axial force.
