Assembly for turbine machine with open rotor contra-rotating propellers, comprising a small duct for the passage of ancillaries

An assembly for an aircraft turbine machine comprising a receiver for a pair of open rotor contra-rotating propellers, the assembly comprising a duct, ancillaries routed inside the duct, and an attachment case comprising an annular installation portion on which a first end of the duct is fixed by attachment means, the annular installation portion of the attachment case being arranged around the first end of the duct,

• wherein the attachment means in an assembled configuration include:
• a split ring fitted with internal projections housed inside corresponding orifices formed through said first end of the duct;
• a radial loading surface of the split ring made on the annular installation portion of the attachment case, the radial loading surface being tapered and narrowing along a first axial direction of the duct, and being in contact with a complementary tapered peripheral surface of the split ring;
• axial loading means of axially loading the split ring along said first direction, said axial loading means being blocked in the axial direction on the annular installation portion of the attachment case.