Drain tube for a low-pressure shaft of a turbomachine

1 . A drain tube for mounting coaxially inside a low-pressure shaft of a turbomachine, the tube comprising a hollow metal tubular portion of length substantially identical to that of the shaft inside which said tube is to be mounted, wherein the outside surface of the metal portion of the tube is covered over at least a fraction of its length in a composite material based on fibers oriented along a direction that is substantially longitudinal so as to confer bending strength to the tube.

2 . A tube according to claim 1 , in which the composite material further comprises braided fibers for holding the longitudinal fibers.

3 . A tube according to claim 1 , in which the metal portion is provided at an upstream end with a fastener endpiece for fastening to an upstream end of the shaft inside which said tube is to be mounted.

4 . A tube according to claim 3 , in which the fastener endpiece includes an antirotation device for co-operation with the shaft in which said tube is to be mounted.

5 . A tube according to claim 3 , in which the fastener endpiece includes at least one sealing gasket for co-operating with the shaft in which said tube is to be mounted.

6 . A tube according to claim 1 , in which the metal portion is made of titanium.

7 . A tube according to claim 1 , in which the composite material is made of resin-impregnated carbon fibers.

8 . A tube according to claim 7 , in which the longitudinal carbon fibers cover 50% to 75% of the outside surface of the metal portion.

9 . A low-pressure turbomachine shaft, including a drain tube according to claim 1.