Timepiece movement of reduced height with a large power reserve

A timepiece gear train device of reduced height with a large power reserve, comprising at least one means of energy storage arranged to be powered by a motion imparted to a winding stem and/or to an oscillating weight, said energy storage means comprising at least one barrel, and said gear train device driving display means which include at least one cannon-pinion and an hour wheel driven directly about a main pivot axis by a motion work, said gear train device comprising, driven directly or indirectly by said at least one barrel, at least one driving wheel pivoting about a secondary pivot axis external to said at least one barrel, and said driving wheel being friction coupled to said motion work on a friction surface coaxial to said secondary pivot axis of said driving wheel, and said main pivot axis being secant to said at least one barrel, wherein said driving wheel includes a driving cannon-pinion pivoting about a wheel body along said secondary pivot axis and connected to a shoulder of said wheel body which forms said friction surface by friction means formed by a friction spring, and wherein said driving cannon-pinion cooperates with a minute wheel belonging to said motion work and pivoting about a minute axis.