Plasticizing device, injection molding device, and three-dimensional shaping device

A plasticizing device comprising:

• a rotary body having a groove forming surface in which a groove is formed and having a screw configured to rotate around a rotation axis, the rotary body being configured with a main part and a flange outwardly extending from the main part along a radial direction perpendicular to the rotation axis, the flange having a first contact surface extending along the radial direction;
• a barrel having a facing surface facing the groove forming surface and having a communication hole through which a plasticized material flows out to an outside;
• a heater configured to heat the material supplied to the groove;
• a screw case accommodating the screw, the screw case having a ledge, the ledge having a second contact surface extending along the radial direction, the first and second contact surfaces directly facing and aligning each other along the rotation axis;
• and
• one of a biasing portion and a sealing portion,
• wherein the biasing portion is configured to bias the rotary body from the screw case toward the rotary body and having a rotary member having a hardness lower than a hardness of the rotary body at a tip end of the biasing portion, and the biasing portion is provided in the ledge directly adjacent to the first contact surface, and
• the sealing portion is configured to seal a fluid in a space between the screw case and the rotary body, and the sealing portion is provided in the ledge directly adjacent to the first contact surface.