The energy required for friction welding is obtained by directly connecting the drive motor within a predetermined time. One workpiece is installed on the rotating device driven by the motor, while the other workpiece is fixed and does not rotate. The work-piece driven by the motor rotates at a predetermined constant speed, and then the two work-pieces to be welded are pressed together axially, starting to generate heat through friction. When this friction lasts for a predetermined period of time or reaches a predetermined axial shortening, the rotary drive motor is disengaged and quickly braked. After the rotation stops, the upset axial force remains constant or increases for a predetermined period of time.

The energy required for friction welding is mainly provided by the rotating kinetic energy stored on the welding machine. One workpiece is connected to the flywheel, and the other workpiece is fixed without rotation. Accelerate the flywheel to the predetermined speed to store the energy required for welding, then drive the motor to disengage and press the two workpieces together with the welding axial friction, starting to generate heat through friction. With the reduction of the flywheel speed, the kinetic energy stored in the rotating flywheel will be converted into the heat energy generated by the welding section friction and lost. The top false axial force can be increased before the rotation stops. After the rotation stops, the top false axial force remains constant for a predetermined period of time.