Lever for rotating a turbomachine variable-pitch stator vane about its pivot
View Patent ↗A lever for rotating about its pivot a turbomachine variable-pitch stator vane: including a first zone for attachment to a lever drive member, a second zone for attachment to the variable-pitch stator vane, and a third zone of elongate shape between the first zone and the second zone is disclosed. A vibration-damping laminate is applied to at least one surface portion of at least one of the zones of the lever. The laminate includes at least one layer of viscoelastic material in contact with the surface portion and a backing layer of rigid material.
1. A lever for rotating about its pivot a turbomachine variable-pitch stator vane comprising:
a first zone for attachment to a lever drive member;
a second zone for attachment to said variable-pitch stator vane, said second zone including a radial upper face and a radial lower face; and
a third zone of elongate shape between the first zone and the second zone, said third zone including a radial upper face and a radial lower face, said radial upper face of said second zone being radially higher than said radial upper face of said third zone and said radial lower face of said second zone being radially lower than said radial lower face of said third zone;
wherein a vibration-damping laminate includes a first part applied to a surface portion of the second zone of the lever, a second part applied to a surface portion of the third zone of the lever, and an intermediate part which connects the first part to the second part, a portion of the intermediate part being free of contact of the lever, and
wherein the laminate includes at least one layer of viscoelastic material in contact with said surface portion and a backing layer of rigid material.
2. The lever as claimed in claim 1 , wherein the vibration-damping laminate is bonded to said surface portion.
3. The lever as claimed in claim 1 , wherein the vibration-damping laminate is kept pressed against said surface portion by a mechanical device.
4. The lever as claimed in claim 1 , wherein the second part of the vibration-damping laminate entirely covers the surface portion of said third zone.
5. The lever as claimed in claim 1 , comprising at least one vibration-damping laminate in the form of strips, at least two of these, of a width narrower than the width of the third zone.
6. The lever as claimed in claim 1 , wherein the laminate is made up of a stack of viscoelastic layers and of rigid layers in alternation, the characteristics of the viscoelastic material varying or being the same from one layer to another.
7. The lever as claimed in claim 6 , wherein the characteristics of the rigid material vary from one layer to another.
8. A turbomachine comprising at least one lever as claimed in claim 1 for rotating a variable-pitch stator vane about its pivot.
9. A gas turbine engine compressor comprising at least one lever as claimed in claim 1 for rotating a variable-pitch flow straightener vane about its pivot.
10. The lever as claimed in claim 1 , wherein edges along a thickness of the second zone and edges along a thickness of the third zone are free of the laminate.