Bladed assembly with inter-platform connection by friction member
A bladed assembly for a turbomachine includes: a plurality of blades distributed about an axis and each including an airfoil and a platform formed at a free end of the blade. The platform of each blade includes a friction member and an opening that is oblong in a circumferential direction with respect to the axis. The friction member is engaged through the opening formed in the platform of a circumferentially adjacent blade within the bladed assembly with a clearance allowing the friction member to move at least in the circumferential direction within the opening. Mutual separation of the platforms in the circumferential direction during operation due to vibrations of the blades causes the friction member to rub against an edge of the opening and thereby dissipate energy.
1 . A bladed assembly for a turbomachine, comprising:
a plurality of blades distributed about an axis and each comprising an airfoil, and a platform formed at a free end of the blade, and wherein the platform of each blade includes a friction member and an opening that is oblong in a circumferential direction with respect to the axis, the friction member being engaged through the opening formed in the platform of a circumferentially adjacent blade within the bladed assembly with a clearance allowing the friction member to move at least in the circumferential direction within the opening.
2 . The bladed assembly according to claim 1 , wherein an angle between a plane of an oblong closed section of the opening and a radial direction with respect to the axis, at said opening, is between 45 degrees and 90 degrees.
3 . The bladed assembly according to claim 2 , wherein the plane of said oblong closed section is orthogonal to the radial direction.
4 . The bladed assembly according to claim 2 , wherein said friction member has a geometry of revolution about an axis that extends in said radial direction.
5 . The bladed assembly according to claim 2 , wherein the platform of each blade has a surface from which said friction member protrudes radially, and an engagement part that extends circumferentially protruding from a circumferential end of the platform, which is radially offset with respect to the surface, and through which said opening is formed.
6 . The bladed assembly according to claim 5 , wherein said friction member is integrally formed with said platform.
7 . The bladed assembly according to claim 5 , wherein the friction member has an end surface level with a surface of the engagement part.
8 . A turbine for a turbomachine, comprising at least one bladed assembly according to claim 1 .
9 . A turbomachine comprising at least one turbine according to claim 8 .