Dental cleaning device and handpiece assembly thereof

A handpiece assembly for a dental cleaning device, comprising:

• a main body, having a connection hole extending along a length direction thereof and a connection groove located at one end thereof, wherein the connection groove communicates with the connection hole and forms an opening facing one side of the main body, a middle portion of a bottom wall of the connection groove, which is away from the opening, is provided with a first shaft hole penetrating outwards;
• a first rotating body, rotatably disposed in the connection hole, wherein an end of the first rotating body facing the connection groove is provided with a drive gear portion;
• a second rotating body, comprising a limit portion, a first shaft portion, a second shaft portion, and a driven gear portion, wherein the first shaft portion and the second shaft portion are extended outwards from opposite ends of the limit portion respectively, the limit portion, the first shaft portion, and the driven gear portion are disposed in the connection groove, the limit portion is abutted against the bottom wall of the connection groove, the driven gear portion is meshed with the drive gear portion so that rotation of the first rotating body is transferred to the second rotating body with a changed direction, the second shaft portion is disposed in the first shaft hole with a clearance fit, and an end of the second shaft portion away from the limit portion is configured to connect to a dental cleaning member to drive the dental cleaning member to rotate;
• and
• a cover, fixedly mounted over the opening, wherein an inner wall of the cover is provided with a second shaft hole, and a terminal end of the first shaft portion is inserted into the second shaft hole with a clearance fit.