US 11,867,259 B2
Mechanical gearbox for an aircraft turbomachine
Guillaume Pierre Mouly, Moissy-Cramayel (FR); Adrien Louis Simon, Moissy-Cramayel (FR); and Dhafer Ghribi, Moissy-Cramayel (FR)
Assigned to SAFRAN TRANSMISSION SYSTEMS, Colombes (FR)
Filed by SAFRAN TRANSMISSION SYSTEMS, Colombes (FR)
Filed on Nov. 4, 2021, as Appl. No. 17/453,607.
Claims priority of application No. 2011537 (FR), filed on Nov. 10, 2020.
Prior Publication US 2022/0145769 A1, May 12, 2022
Int. Cl. F16H 1/28 (2006.01); F02C 7/36 (2006.01)
CPC F16H 1/28 (2013.01) [F02C 7/36 (2013.01); F05D 2260/40311 (2013.01); F16H 2001/289 (2013.01); F16H 2001/2872 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A mechanical gearbox for a turbomachine, in particular for an aircraft, this gearbox comprising:
a sun gear rotatable about a first axis and comprising an external toothing comprising two series of adjacent teeth,
a stationary ring gear which extends around the first axis and which carries an internal toothing comprising two series of teeth, this stationary ring gear being configured to be secured to a stator of the turbomachine, and
planet gears which are in mesh with the sun gear and the stationary ring gear, the planet gears being carried by a planet carrier which is rotatable about the first axis and each of the planet gears having a dual-stage gearing and comprising a first external toothing of mean diameter D1 and comprising two series of adjacent teeth, and a second external toothing of mean diameter D2, different from D1, and comprising two series of teeth, the two series of teeth of the first toothing of each of the planet gears being meshed with the two series of teeth of the toothing of the sun gear, wherein it further comprises:
a movable ring gear which extends about the first axis and which carries an internal toothing with two series of adjacent teeth, this movable ring gear being independent of the stationary ring gear and being configured so as to be secured to a rotor of the turbomachine, each of the planet gears being meshed with the sun gear and the stationary and movable ring gears,
wherein the series of teeth are arranged symmetrically with respect to a median plane perpendicular to the first axis,
wherein the movable ring gear comprises two half ring gears secured to each other and respectively carrying the two series of teeth, these two series of teeth being meshed with the two series of teeth of the first toothing of each of the planet gears and the stationary ring gear comprising two annulus disposed on each side of the movable ring gear and respectively carrying the two series of teeth, these two series of teeth being meshed with the two series of teeth of the second toothing of each of the planet gears, and
wherein said planet carrier comprises two coaxial annulus which are centered to said first axis and which are connected respectively to axial ends of said planet gears so that said dual-stage gearing is interposed between said two coaxial annulus, each of said planet gears being rotatable relative to said planet carrier about a second axis which is parallel to said first axis.