Dental handpiece and head thereof, and root canal preparation machine

A head of a dental handpiece, wherein the head comprises a head housing, wherein a machine core cavity is provided in the head housing;

• and a rotatable machine core and a driving gear are provided in the machine core cavity;
• the driving gear is sleeved over one end of the machine core, and the machine core is capable of moving along an axial direction of the driving gear;
• and
• a reciprocating driving mechanism is further provided in the machine core cavity, and the reciprocating driving mechanism is configured to drive the machine core to perform reciprocating movement along an axial direction of the machine core
• wherein the reciprocating driving mechanism is a cam mechanism, comprising a driving block, a driving protrusion, and an elastic member, wherein
• the driving block is located at an end of the machine core cavity away from the driving gear, and an end surface of the driving block close to the driving gear is provided with an annular driving surface which is coaxial to the machine core, wherein a distance between the driving surface and the driving gear varies gradually along a circumferential direction of the driving block;
• the driving protrusion is provided on the machine core and protrudes towards the driving surface;
• and
• the elastic member is configured to keep the driving protrusion abutting against the driving surface,
• wherein the elastic member is sleeved over the machine core and held between the driving gear and the machine core.