Helicopter shaft vibration simulator

Simulator of the vibrations of the shaft supporting the rotor of a helicopter comprising:

• a fixed reference structure;
• a shaft-carrying mobile structure fitted on the fixed reference structure so as to have one degree of translational freedom in a vertical direction and two degrees of rotational freedom about two horizontal axes, namely the roll and pitch axes, which are perpendicular to one another;
• three linear exciters integral with the fixed reference structure and having parallel vertical axes and acting on the shaft-carrying mobile structure at three points forming an equilateral triangle, whose centre is located on the axis of the shaft;
• and
• a double pivot hydrostatic ball joint connecting each linear exciter acts to the mobile shaft-carrying structure to allow an angular, lateral misalignment.

Simulator of the vibrations of the shaft supporting the rotor of a helicopter comprising:

• a fixed reference structure;
• a shaft-carrying mobile structure fitted on the fixed reference structure so as to have one degree of translational freedom in a vertical direction and two degrees of rotational freedom about two horizontal axes, namely the roll and pitch axes, which are perpendicular to one another;
• three linear exciters integral with the fixed reference structure and having parallel vertical axes and acting on the shaft-carrying mobile structure at three points forming an equilateral triangle, whose centre is located on the axis of the shaft;
• and
• wherein the shaft-carrying mobile structure has an interface plate articulated by a ball joint on a guide column having a vertical axis coinciding with the axis of the shaft when the exciters are at rest, the guide column cooperating with the guidance means mounted on the fixed reference structure and allowing a displacement of said column along its axis, the interface plate also cooperating with the fixed reference structure by movement limiting means preventing any rotation of the interfaced plate around the vertical axis of the guide column.

Simulator of the vibrations of the shaft supporting the rotor of a helicopter comprising:

• a fixed reference structure;
• a shaft-carrying mobile structure fitted on the fixed reference structure so as to have one degree of translational freedom in a vertical direction and two degrees of rotational freedom about two horizontal axes, namely the roll and pitch axes, which are perpendicular to one another;
• three linear exciters integral with the fixed reference structure and having parallel vertical axes and acting on the shaft-carrying mobile structure at three points forming an equilateral triangle, whose centre is located on the axis of the shaft;
• and
• control means sensitive to signals supplied by accelerometers fitted to the mobile portions of the exciters, in order to supply control signals of the exciters and which are reciprocally phase displaced by 120.degree..