There are two types of electric wrench: safety clutch type and impact type.
The safety clutch type is a structural type that uses a safety clutch mechanism that trips when a certain torque is reached to complete the assembly and disassembly of threaded parts; the impact type uses an impact mechanism to complete the assembly and disassembly of threaded parts with its impact torque. The former is generally only suitable for the manufacture of electric wrenches of M8mm and below due to its simple structure, small output torque and certain reaction torque; the latter has a more complex structure and high manufacturing process requirements, but its output torque is large and the reaction torque is large. Very small, generally suitable for the manufacture of larger size electric wrenches.
The impact electric wrench is composed of a motor, a planetary gear reducer, a ball screw groove impact mechanism, a forward and reverse power switch, a power connection device and a motorized sleeve.
Impact electric wrenches include single-phase series-excited electric wrenches and three-phase electric wrenches according to the type of motor used.
The electric motor of the single-phase series electric wrench is installed in the plastic casing. The plastic casing is used both as a structural member to support the motor and as additional insulation for the motor stator. When the impact electric wrench is assembling or disassembling the threaded parts, there is a large axial tension between the end face of the plastic casing of the motor and the plastic front cover of the planetary gear reducer and the ball screw groove impact mechanism, as well as the planetary gear. The reducer requires high assembly accuracy, so metal inserts are set at the mouth, bearing chamber and threaded connection of the plastic housing to enhance the rigidity of the housing, improve the machining accuracy of the plastic housing and the ability of the joint to withstand axial force. ability.
