Transmission structural unit

A gear constructional unit with a gear housing is provided. In order to make the effective diameter of the inner gear elements greater, as well as to ensure a simple assembly and exchangeability of the individual gear elements, for example coupling arrangements and planetary wheel sets, there are provided at least two bar-form guide elements, which extend, as viewed in an axial direction, over at least a part of the axial extent of the cylindrical inner space, on which a large number of gear elements are mounted in fixed position with respect to the housing. The bar-form guide elements are located adjacent to the cylindrical inner space, outside of a zone having the greatest dimension of the cylindrical inner space relative to the gear housing dimension, and are arranged in recesses in the gear housing which are connected with the inner space.