Rotatable ultrasonic vibration device

A rotatable ultrasonic vibration device comprising:

• a shell with a mounting cavity in the shell, a handle connecting portion on the shell, and a mounting hole communicating with the mounting cavity;
• a hollow locking rod mounted in the mounting cavity, with one end of the hollow locking rod in a length direction thereof facing the mounting hole, and having a center hole in the length direction;
• a piezoelectric transducer mounted in the mounting cavity and surrounding the hollow locking rod, with the hollow locking rod fixing the piezoelectric transducer within the shell;
• a first amplitude-change pole mounted in the center hole, fixedly connected to the hollow locking rod at one end of the first amplitude-change pole in a length direction thereof, and with at least a portion of the length of the first amplitude-change pole located in the space surrounded by the piezoelectric transducer;
• an instrument rod, directly or indirectly connected to the other end of the first amplitude-change pole in the length direction thereof, with an instrument working portion located outside the shell and connected to the instrument rod, and the instrument rod being rotatably connected relative to the first amplitude-change pole;
• and
• a rotation transmission assembly rotatably mounted on the shell, matched with the instrument rod to transmit rotation torque to the instrument rod, wherein:
• the instrument rod comprises an internal segment and a step positioning segment, wherein the internal segment is disposed within the first amplitude-change pole, with one end of the internal segment fitting with the rotation transmission assembly, wherein the step positioning segment is connected to the other end of the internal segment and is located outside the first amplitude-change pole, with the instrument working portion and the internal segment located on two opposite sides of the step positioning segment;
• the ultrasonic vibration device further comprises a pressing spring, which is matched with the shell and the instrument rod, respectively, to press the step positioning segment against an end of the first amplitude-change pole;
• and
• the rotation transmission assembly comprises a first gear mounted on the hollow locking rod and a second gear meshing with the first gear, wherein a central transmission hole of the first gear is non-circular and engages with a transmission segment of the instrument rod.