An oil transfer assembly has a fixed structure, with at least one inlet for receiving lubricating oil, and an interface member rotating about an axis and having a front face, from which at least one duct starts for conveying the lubricating oil; the assembly is provided with a slide having an annular chamber, which is delimited axially, on one side, by the front face and connects the inlet with the duct; the slide is coupled to the front face so as to guarantee a seal for the fluid of the annular chamber and engages a guide seat provided in the structure in an axially sliding manner.