Hydromechanical power split transmission assembly (1, 1', 1") comprising a first power branch which is a mechanical transmission branch; a second power branch comprising an infinitely adjustable transmission unit (5); an epicyclic reduction gear (7). The epicyclic reduction gear (7) comprises a gear ring assembly (35), a sun gear (37), one or more satellite gears (39) and a carrier assembly (41, 41'). The input shaft (3) drives the gear ring assembly (35). The first and the second power branches are arranged for reversibly varying the ratio (Ä G [tau-G]) between the rotational speeds of the output (19) and the input shafts (3). Transmission concept for mobile machines (e.g. Wheel loader, Telehandler, Backhoe loader) with both high efficiency and high maximum drive speed with as low complexity as possible. Main drivers gain a high efficiency for fuel consumption benefit under delivering high vehicle performance and low manufacturing cost at the same time.
