Laundry washing-drying machine and bellow for a laundry washing-drying machine

A laundry washing-drying machine comprising: a casing; a tub suspended in the casing; an elastically deformable bellow having a ring shaped main portion sealingly connected to the casing and to the tub, at a door of the machine; a projection portion, made in one piece with the main portion and radially extending from the main portion to a distal end; a dry air duct, supported in the casing and fixedly connected to an air drying unit, and having a downstream end; a bellow duct formed within the projection portion of the bellow, from an inlet mouth, formed at the distal end of the projection portion and connected to the downstream end of the dry air duct, to an outlet mouth, formed in the main portion of the bellow, at the projection portion, and open into the tub. The projection portion of the bellow has a substantially flat shape, with two major sides and two minor sides, and the bellow duct comprises at least a protrusion, internally formed in one of the major sides. Thus, the risk of obstructions of the bellow duct because of deformations induced by vibrations is avoided, thanks to the protrusion.