Mechanical power transmission module

A mechanical power transmission module comprising a housing and a plurality of coaxially mounted mechanical parts, said plurality of mechanical parts forming an epicyclic gear train, one of the inputs/outputs of which is immobilized in relation to the housing, the other two inputs/outputs of the epicyclic gear train being formed by an input assembly and an output assembly, power being furthermore supplied to the plurality of mechanical parts by an input shaft of the transmission module coaxial with the parts of the plurality of mechanical parts, the input shaft being coupled to the output assembly by means of the input assembly in a first axial position (P1) of the input shaft in relation to the housing defining a first gear ratio of the transmission module, the transmission module being further characterized in that the input assembly comprises a central through-bore, said through-bore and the input shaft carrying complementary splines for coupling the input shaft with the input assembly, the input shaft slidably mounted in relation to the housing, sliding in the through-bore to couple with the output assembly in a second position (P2) of the input shaft in relation to the housing, differing from the first position (P1) by an axial translation (T2), in which said complementary splines are no longer engaged, and which defines a second gear ratio of the transmission module, the output assembly comprising a bored pinion coupled to the input assembly by external teeth and a central driver, mounted one relative to the other in an axial sliding link, the driver comprising bearing means to withstand an axial thrust in one direction by a control rod and to withstand an axial thrust by the input shaft in the other direction, and the splines for coupling to and uncoupling from an output and added from of the transmission module,

• coupling means of the output assembly with the input shaft comprises the splines carried by a central bore of the output assembly open toward the through bore and the splines carried by the input shaft,
• the splines carried by a central bore of the output assembly open toward the through bore and the splines carried by the input shaft are carried by means of a sliding sleeve referred to as the output sliding sleeve, and-a compression spring pushes the output sliding sleeve to aid the engagement of said splines of the coupling means.