Timepiece movement of reduced height with a large power reserve

A timepiece gear train device with a power reserve, comprising:

• at least one energy storage means arranged to be powered by a motion imparted to a winding stem and/or to an oscillating weight, said energy storage means including at least one barrel;
• display means including at least one cannon-pinion and an hour wheel driven directly about a main pivot axis by a motion work;
• and
• at least one driving wheel driven directly or indirectly by said at least one barrel, said at least one driving wheel pivoting about a secondary pivot axis external to said at least one barrel, and said at least one driving wheel being friction coupled to said motion work on a friction surface coaxial to said secondary pivot axis of said at least one driving wheel,
• wherein said main pivot axis is secant to said at least one barrel,
• wherein said at least one 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.