Massage structure with variable inner diameter

A massage structure with a variable inner diameter, comprising:

• a deformation assembly, sleeved outside a first massage area;
• wherein the deformation assembly comprises a deformation portion, a constraint portion, and a first engaging portion, wherein the constraint portion and the first engaging portion are respectively disposed at both ends of the deformation portion along a central axis (L1) of the deformation assembly, and the constraint portion is configured to limit movement of the deformation portion;
• a rotating sleeve, provided with a second engaging portion;
• wherein the first engaging portion and the second engaging portion are linked in a coupled manner, such that a rotational motion of the rotating sleeve around the axis (L1) is converted into a linear reciprocating motion of the first engaging portion along the axis (L1);
• and
• the first engaging portion moves closer to or away from the constraint portion along the axis (L1), which drives at least a portion of the deformation portion to deform toward or away from the first massage area, thereby causing an inner diameter of the deformation assembly to shrink or expand.