An anti-torque rotor is described for a helicopter, comprising: a mast rotatable about a first axis; a plurality of blades hinged on the mast, extending along respective second axes transversal to said first axis and rotatable about respective said second axes to alter the respective angles of attack; a control element sliding and rotating with respect to the mast, and operatively connected to said blades to cause the rotation of said blades about respective second axes following a translation of said element along the first axis; a control rod sliding axially along first axis with respect to the mast and angularly fixed with respect to the first axis; and a bearing interposed between the control rod and the control element, sliding along the first axis with respect to the mast and integrally with the control rod; the anti-torque rotor further comprises an interface made of an antifriction material interposed between said control rod and said bearing.

A compound aircraft includes a convertible thruster that pivots between an anti-torque position, a forward thrust position, and intermediate positions. A pilot has two inceptors to control thruster rotor pitch in the anti-torque and forward thrust positions. A mixer mechanically blends the signals from the two inceptors during transition between the anti-torque and forward thrust positions. A transfer rod coaxial with the pivot axis of the convertible thruster conveys convertible thruster pitch commands from the pilot to a pitch control actuator. The pitch control actuator may be located partially within the rotor of an electric motor that rotates the convertible thruster rotor. The electric motor and pitch control actuator are unitary. Both the electric motor and pitch control actuator pivot with the convertible thruster. The pitch actuator output shaft is coaxial to and disposed within a hollow electric motor output shaft.

A pitch change link may include a shaft having a first end region and a second end region, and a bearing cartridge on at least one of the first end region and the second end region. The bearing cartridge may include a bearing and a bearing ring at least partially surrounding the bearing. The bearing ring may have a geometric symmetry and a cross section that is wider at a first end than at a second end, the first end may oppose the second end.

A pitch change link may include a shaft having a first end region and a second end region, and a bearing cartridge on at least one of the first end region and the second end region. The bearing cartridge may include a bearing and a bearing ring at least partially surrounding the bearing. The bearing ring may have a geometric symmetry and a cross section that is wider at a first end than at a second end, the first end may oppose the second end.

A gear box includes a casing having an interior. A rotating component is arranged in the interior of the casing. A bearing including a rotating element, and a fixed element is connected with the casing in the interior. A submersible pump is arranged in the interior of the casing. The submersible pump includes a first housing portion extending about the rotating component fixedly mounted to the casing at the interior. A second housing portion is fixedly mounted to the casing at the interior and is aligned with the first housing portion. The first and second housing portions form a lubricant reservoir which holds lubricant. An impeller is mounted to the rotating component and arranged in the lubricant reservoir. One of the first and second housing portions includes an outlet through which the pumped lubricant is directed toward the rotating element.

A gear box includes a casing having an interior. A rotating component is arranged in the interior of the casing. A bearing including a rotating element, and a fixed element is connected with the casing in the interior. A submersible pump is arranged in the interior of the casing. The submersible pump includes a first housing portion extending about the rotating component fixedly mounted to the casing at the interior. A second housing portion is fixedly mounted to the casing at the interior and is aligned with the first housing portion. The first and second housing portions form a lubricant reservoir which holds lubricant. An impeller is mounted to the rotating component and arranged in the lubricant reservoir. One of the first and second housing portions includes an outlet through which the pumped lubricant is directed toward the rotating element.

An anti-torque rotor is described comprising: a mast rotatable about a first axis; a plurality of blades rotatable about respective second axes; an element slidable along the first axis with respect to the mast, rotating integrally with the mast and operatively connected to the blades; a control rod slidable along axis; a first bearing with a first ring rotating integrally with element, a second ring radially internal to the first ring with respect to the first axis and a plurality of first rolling bodies; a third ring sliding integrally with the control rod along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a standard configuration, in which it prevents the relative rotation of the second and third rings and movable from the standard configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.

A method of providing torque protection and/or thrust protection for the or each propeller of a hybrid helicopter. The hybrid helicopter includes a control system connected to the blades of each propeller and a thrust control configured to generate an order for modifying a pitch of the blades, which order is transmitted to the control system, the propeller(s) being driven in rotation by a mechanical transmission system of the hybrid helicopter. The method includes a step of having the control system keep the pitch of the blades of a propeller within at least one control envelope relating to a thrust generated by the propeller or to a torque exerted in the mechanical transmission system. In this way, the pitch of the blades of each propeller is kept between a lower limit and an upper limit of the control envelope.

A method of providing torque protection and/or thrust protection for the or each propeller of a hybrid helicopter. The hybrid helicopter includes a control system connected to the blades of each propeller and a thrust control configured to generate an order for modifying a pitch of the blades, which order is transmitted to the control system, the propeller(s) being driven in rotation by a mechanical transmission system of the hybrid helicopter. The method includes a step of having the control system keep the pitch of the blades of a propeller within at least one control envelope relating to a thrust generated by the propeller or to a torque exerted in the mechanical transmission system. In this way, the pitch of the blades of each propeller is kept between a lower limit and an upper limit of the control envelope.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.