Radial shaft device for controlling the pitch of fan blades of a turbine engine having an un-ducted fan
A device for controlling pitch of fan blades of a turbine engine including an un-ducted fan, the device including: at least one set of fan blades of adjustable pitch, the set being constrained to rotate with a rotary ring centered on a longitudinal axis and mechanically connected to a turbine rotor, each blade of the set being mounted on a blade root support that is pivotally mounted on the rotary ring; and at least one radial control shaft adjusting pitch of at least two adjacent blades of the set, the control shaft being constrained to rotate with the rotary ring and being configured to pivot about an axis of the shaft, being coupled to the blade root supports of the at least two blades of the set to adjust their pitch via a transmission system including eccentrics connected together by at least one connecting rod.
1. A device for controlling pitch of fan blades of a turbine engine including an un-ducted fan, the device comprising:
at least one set of fan blades of adjustable pitch, the at least one set of fan blades being constrained to rotate with a rotary ring centered on a longitudinal axis and mechanically connected to a turbine rotor, wherein each blade of the at least one set of fan blades is mounted on a blade root support, the blade root support being pivotally mounted on the rotary ring; and
at least one radial control shaft, wherein each of the at least one radial control shaft is coupled to the blade root support of each of at least two adjacent blades of the at least one set of fan blades via a transmission system,
wherein the transmission system comprises a driving eccentric mounted at a top end of the at least one radial control shaft and a driven eccentric mounted on the blade root support of each of the at least two adjacent blades, wherein each driven eccentric is connected to the driving eccentric by at least one connecting rod,
wherein each of the at least one radial control shaft adjusts a pitch of at least two adjacent blades of the at least one set of fan blades, the at least one radial control shaft being constrained to rotate with the rotary ring and configured to pivot about an axis of the radial control shaft while being coupled to the blade root supports of the at least two blades of the at least one set of fan blades to adjust the pitch of the at least two adjacent blades,
wherein the driving eccentric mounted at the top end of the at least one radial control shaft is directly connected to each driven eccentric of each of the at least two adjacent blades by the at least one connecting rod.
2. The device according to claim 1 , wherein each transmission system is situated adjacent roots of the blades.
3. The device according to claim 2 , wherein the driven eccentric mounted on the blade root support of each of the at least two adjacent blades is connected to the driving eccentric by two connecting rods of the at least one connecting rod.
4. The device according to claim 3 , wherein the driving eccentric and each driven eccentric have centers of rotation forming a triangle.
5. The device according to claim 3 , wherein the driving eccentric and each driven eccentric of each of the at least two adjacent blades have axes of rotation that are in alignment in a common plane perpendicular to the longitudinal axis of the turbine engine.
6. The device according to claim 3 , wherein the at least one connecting rod is connected to the driving eccentric and to each driven eccentric of each of the at least two adjacent blades by ball joint connections.
7. A turbine engine including an un-ducted fan, the turbine engine comprising the at least one set of fan blades of adjustable pitch and at least one said device for controlling pitch of the fan blades according to claim 1 .