Method for manufacturing an arm in composite material comprising a transversal bearing designed to receive a fixed or rotating shaft
View Patent ↗The invention relates to a method for manufacturing an arm ( 16 ) in composite material, this arm comprising a main body incorporating a bearing ( 22 ) designed to receive a shaft passing through it transversely, this method comprising the steps of: manufacturing a hub ( 11 ) by winding reinforcing fibers around a generally tubular support ( 12 ); manufacturing at least one sleeve ( 14 ); attaching the hub ( 11 ) to one end of the sleeve ( 14 ) and transversely to the sleeve ( 14 ) in order to form a mandrel; applying one or more layers of braided reinforcing fibers ( 21 ) around this mandrel with a machine for braiding reinforcing fibers ( 19 ); injecting and polymerizing resin into the layer or layers of braided fibers ( 21 ). The invention applies notably to an arm forming an undercarriage rocker arm of an aircraft.
1. A method for manufacturing an arm ( 16 ) in composite material comprising at least one bearing ( 22 ) designed to receive a fixed or rotating shaft passing through the arm ( 16 ) transversely, this method comprising the steps of:
manufacturing at least one hub ( 11 ) by winding reinforcing fibers around a generally tubular support ( 12 );
manufacturing at least one sleeve ( 14 );
manufacturing a mandrel ( 15 ) by attaching each hub ( 11 ) to at least one sleeve end so that each hub ( 11 ) extends transversely to each sleeve ( 14 );
applying one or more braided reinforcing fibers ( 21 ) around this mandrel ( 15 ) and over its whole length with a machine ( 17 ) for braiding reinforcing fibers ( 19 );
covering ends of the tubular support when applying a layer or layers of braided reinforcing fibers;
injecting and polymerizing resin into a layer or a plurality of layers of braided fibers ( 21 ) and optionally into the wound fiber or fibers of the hub ( 11 ) in order to establish a cohesion rigidly binding at least the layer or the plurality of layers of braided fibers ( 21 ) with the hub ( 11 ) that they surround;
removing the portions of the layer or layers of braided reinforcing fibers which cover each end of the tubular support in order to expose the ends of the tubular support; and
machining the layer or the plurality of layers of braided reinforcing fibers ( 21 ) at each end of the generally tubular support ( 12 ) in order to clear each end of this support ( 12 ).
2. The method according to claim 1 , in which each sleeve ( 14 ) is manufactured with pieces of fabric of reinforcing fibers preimpregnated with resin, in which the reinforcing fibers ( 13 ) wound around the generally tubular support ( 12 ) are also preimpregnated with resin, and in which the mandrel ( 15 ) is prepolymerized before application of the layers of braided reinforcing fibers ( 21 ).
3. The method according to claim 1 , in which the reinforcing fibers are wound around the generally tubular support ( 12 ) so as to form a hub having a generally spherical outer shape.
4. The method according to claim 1 , in which the generally tubular support ( 12 ) has a larger section in its central portion than at its ends.
5. The method according to claim 1 , in which each sleeve end ( 14 ) is bonded to the hub ( 11 ).
6. The method according to claim 1 , in which each sleeve has an end having a flared shape in order to closely follow the outer shape of the hub ( 11 ) to which this end is attached.
7. The method according to claim 1 , in which the hub ( 11 ) is situated at one end of the mandrel ( 15 ).
8. The method according to claim 1 , in which the mandrel is manufactured by assembling to the hub ( 11 ) two sleeves extending on either side of the hub ( 11 ).