Hinge structure and foldale electronic device including the same

A foldable electronic device comprising:

• a flexible display;
• a first housing and a second housing;
• a hinge housing;
• and
• a hinge structure, at least a portion of which is seated in the hinge housing,
• wherein the hinge structure includes:
• a first rotary member coupled to the first housing;
• a second rotary member coupled to the second housing;
• a first arm part coupled to the first rotary member and including a first rotary a second arm part coupled to the second rotary member and including a second rotary cam;
• a fixed cam part including a first fixed cam engaged with the first rotary cam, a second fixed cam engaged with the second rotary cam, and a cam body connecting the first fixed cam and the second fixed cam;
• a stopper configured to restrict rotational angles of the first arm part and the second arm part;
• and
• an additional structure having a specific thickness and disposed between the stopper and the fixed cam part,
• wherein the first rotary cam is configured to rotate about a first axis through a center of the first fixed cam and a center of the first rotary cam, and wherein the second rotary cam is configured to rotate about a second axis through a center of the second fixed cam and a center of the second rotary cam.