US 11,052,994 B2
System for changing the pitch of a turboprop engine comprising an upstream pair of contrarotating propellers
Gilles Alain Charier, La Grande Paroisse (FR); and Thomas Julien Nguyen Van, Alfortville (FR)
Assigned to SAFRAN AIRCRAFT ENGINES, Paris (FR)
Appl. No. 16/67,523
Filed by SAFRAN AIRCRAFT ENGINES, Paris (FR)
PCT Filed Dec. 22, 2016, PCT No. PCT/FR2016/053644
§ 371(c)(1), (2) Date Jun. 29, 2018,
PCT Pub. No. WO2017/118791, PCT Pub. Date Jul. 13, 2017.
Claims priority of application No. 1650020 (FR), filed on Jan. 5, 2016.
Prior Publication US 2020/0247528 A1, Aug. 6, 2020
Int. Cl. B64C 11/30 (2006.01); F01D 7/00 (2006.01); F02C 3/067 (2006.01); F02C 7/36 (2006.01)
CPC B64C 11/306 (2013.01) [F01D 7/00 (2013.01); F02C 3/067 (2013.01); F02C 7/36 (2013.01); F05D 2250/44 (2013.01); F05D 2260/40311 (2013.01)] 12 Claims
OG exemplary drawing
 
1. Turbine engine module comprising:
an upstream propulsive unit comprising a propellers doublet respectively upstream and downstream, each of said upstream and downstream propellers comprising blades,
a power turbine shaft intended for rotating the propellers doublet,
a speed reducer connected to the propellers doublet and driven by the power turbine shaft,
a pitch-changing system comprising a cylinder that controls the pitch of the blades of the upstream propeller,
a rotational axis (XX) of the propellers doublet being shifted in relation to a rotational axis (YY) of the power turbine shaft, characterised by the fact that the cylinder is placed downstream of the speed reducer, and in that the pitch-changing system comprises a control shaft for controlling the pitch of the blades that connect the cylinder to the blades of the upstream propeller, the cylinder being arranged in such a way as to move the control shaft axially, the speed reducer of which comprising a differential gear train with a sun gear, a planetary carrier and a ring gear, with the control shaft for controlling the pitch of the blades passing through the sun gear.