Table and a method for needling a textile structure formed from an annular fiber preform, with radial offsetting of the needling head

A circular needling table for needling a textile structure made from an annular fiber preform, the table comprising:

• a horizontal top on which an annular fiber preform is to be placed;
• a driver system constructed and arranged to drive the fiber preform in rotation about a vertical axis of rotation;
• a needling device for needling the fiber preform, the device comprising a needling head extending over a predetermined angular sector of the table top and to be driven with vertical reciprocating motion relative to the table top;
• and
• a mover system constructed and arranged to move the needling head during the needling of the fiber preform in a direction that is radial relative to the axis of rotation of the fiber preform,
• wherein the needling device comprises:
• a vertical support to be driven with vertical reciprocating motion relative to the table top and having the needling head mounted thereon;
• and
• an electric motor mounted on the support and having an outlet shaft coupled to the needling head in order to move it along a direction that is radial relative to the axis of rotation of the fiber preform, and
• wherein the motor is a linear stepper motor and said motor is configured to position the needling head in at least three different radial positions relative to the axis of rotation of the fiber preform and wherein the linear stepper motor positions the needling head at different radial positions between successive turns of the fiber preform about the vertical axis of rotation.