Abstract: A heat exchanger for a transmission unit of an aircraft is described that comprises: a first module defining a first feed path for a first fluid to be cooled; a second module defining a second feed path for a second cooling fluid; the first and second feed paths being thermally coupled to each other; each second module comprising: at least one cell formed by an inlet for a second cooling fluid; an outlet for the second cooling fluid, which is arrange on the opposite side to the inlet along a first direction; a first wall thermally coupled to the first path; a pair of second walls; and a plurality of fins projecting in a cantilever fashion from the first wall. The heat exchanger further comprises at least a first row of fins, which lie on a plane orthogonal to the first direction, the fins of the first row extending at progressively increasing distances from one of the second walls along a second direction orthogonal to the first direction.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis; and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses; and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and each control unit comprises: a belt coupled to the support assembly and a drive unit coupled to the first belt, to cause the rotation of the first support assembly with respect to said transmission device.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis, and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses, and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and comprises a set of drive gear teeth integral with the first support assembly, a cogwheel with a set of control gear teeth meshing with the drive gear teeth, and an actuator to cause the rotation of the cogwheel about a second axis and of the first mass about said first axis.

Abstract: An aircraft is described comprising a transmission unit with a first module and a lubrication system; the first module comprises a casing and a movable member; the lubrication system comprises a header, a nozzle fed with the lubricating fluid and designed to feed the lubricating fluid inside the casing of the first module, a collection tank for the lubricating fluid injected by the nozzle, and recirculation means designed to cause the recirculation of the lubricating fluid from the collection tank to the feed header; the first module comprises a valve available in a first configuration, in which it enables the outflow of said lubricating fluid from said module to the recirculation means when the pressure of the lubricating fluid inside the header is greater than a threshold value; and in a second configuration, in which it fluidically isolates the module from the recirculation means when the pressure of the lubricating fluid inside the header is less than the threshold value.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis, and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses, and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and comprises a set of drive gear teeth integral with the first support assembly, a cogwheel with a set of control gear teeth meshing with the drive gear teeth, and an actuator to cause the rotation of the cogwheel about a second axis and of the first mass about said first axis.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis; and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and each control unit comprises: a belt coupled to the support assembly and a drive unit coupled to the first belt, to cause the rotation of the first support assembly with respect to said transmission device.

Abstract: A rotor for an aircraft is described that comprises: a hub rotatable about an axis and, in turn, comprising a plurality of blades; a mast connectable to a drive member of the aircraft and connected to the hub to drive the hub in rotation about the axis; and damping means to dampen the transmission of vibrations to the mast in a plane orthogonal to the axis; the damping means comprising at least a first mass and a second mass that can eccentrically rotate about the axis with a first and a second speed of rotation, respectively; the first mass and second mass are operatively connected to the mast to generate, respectively, a first and a second damping force on the mast having a main component in a direction radial to the axis; the rotor comprises a transmission unit, which is interposed between the mast and the first and second masses so as to drive the first and second masses in rotation.

Abstract: A heat exchanger for a transmission unit of an aircraft is described that comprises: a first module defining a first feed path for a first fluid to be cooled; a second module defining a second feed path for a second cooling fluid; the first and second feed paths being thermally coupled to each other; each second module comprising: at least one cell formed by an inlet for a second cooling fluid; an outlet for the second cooling fluid, which is arrange on the opposite side to the inlet along a first direction; a first wall thermally coupled to the first path; a pair of second walls; and a plurality of fins projecting in a cantilever fashion from the first wall. The heat exchanger further comprises at least a first row of fins, which lie on a plane orthogonal to the first direction, the fins of the first row extending at progressively increasing distances from one of the second walls along a second direction orthogonal to the first direction.

Abstract: A rotor for an aircraft is described that comprises: a hub rotatable about an axis and, in turn, comprising a plurality of blades; a mast connectable to a drive member of the aircraft and connected to the hub to drive the hub in rotation about the axis; and damping means to dampen the transmission of vibrations to the mast in a plane orthogonal to the axis; the damping means comprising at least a first mass and a second mass that can eccentrically rotate about the axis with a first and a second speed of rotation, respectively; the first mass and second mass are operatively connected to the mast to generate, respectively, a first and a second damping force on the mast having a main component in a direction radial to the axis; the rotor comprises a transmission unit, which is interposed between the mast and the first and second masses so as to drive the first and second masses in rotation.

Abstract: A sealing ring for a seal assembly is described that comprises: a main body rotating about an axis; and a first surface, which is defined by the main body, extends transversely to the axis and is suitable for abutting against a further sealing ring in a direction parallel to the axis; the first surface comprises a plurality of grooves forming respective hydropads; the grooves are delimited by a first edge and a second edge facing one another; the first edge and the second edge delimit the grooves in a circumferential direction to said axis; at least one of the first edge and the second edge is shaped like an elliptical arc, which has coincident or separate foci; comprises first grooves and second grooves alternating with one another in a circumferential direction to said axis and staggered from each other in a radial direction to said axis.

Abstract: A sealing ring for a seal assembly is described that comprises: a main body rotating about an axis; and a first surface, which is defined by the main body, extends transversely to the axis and is suitable for abutting against a further sealing ring in a direction parallel to the axis; the first surface comprises a plurality of grooves forming respective hydropads; the grooves are delimited by a first edge and a second edge facing one another; the first edge and the second edge delimit the grooves in a circumferential direction to said axis; at least one of the first edge and the second edge is shaped like an elliptical arc, which has coincident or separate foci; comprises first grooves and second grooves alternating with one another in a circumferential direction to said axis and staggered from each other in a radial direction to said axis.

Abstract: A system for cooling a transmission of a hover-capable aircraft, the system having: a stator; a heat exchanger connectable thermally to the transmission; a fan for creating a current of a first heat-carrying fluid from the heat exchanger to the fan itself, to remove heat from the heat exchanger; a rotary member, which rotates about an axis to rotate an impeller of the fan about the axis; and a bearing supporting the rotary member for rotation about the axis; the system also having cooling means for cooling the bearing, and in turn having conducting means for conducting a current of a second heat-carrying fluid along a path from an outside environment, external to the bearing, to and to cool the bearing itself.

Abstract: A system for cooling a transmission of a hover-capable aircraft, the system having: a stator; a heat exchanger connectable thermally to the transmission; a fan for creating a current of a first heat-carrying fluid from the heat exchanger to the fan itself, to remove heat from the heat exchanger; a rotary member, which rotates about an axis to rotate an impeller of the fan about the axis; and a bearing supporting the rotary member for rotation about the axis; the system also having cooling means for cooling the bearing, and in turn having conducting means for conducting a current of a second heat-carrying fluid along a path from an outside environment, external to the bearing, to and to cool the bearing itself.