Assembly forming a seal for a turbomachine including a brush seal and at least one lip

An assembly forming a seal for a turbomachine, used to form a seal between two elements of the turbomachine rotating relative to one another, and being rotationally symmetrical around an axis of the assembly forming a seal, including:

• a brush seal, which is annular around the axis of the assembly forming a seal, having multiple elastic sealing bristles, intended to be attached to one of the two elements of the turbomachine rotating relative to one another other,
• at least one lip, which is annular around the axis of the assembly forming a seal, extending radially in the direction of the brush seal, intended to be attached to the other of the two elements of the turbomachine rotating relative to one another, where the said at least one lip penetrates at least partially into the brush seal,
• and wherein the total radial length of the bristles of the brush seal is chosen to allow sufficient penetration of the said at least one lip into the brush seal, where this total radial length of the bristles of the brush seal satisfies the following relationship:
• lP≧d+drmax, where:
• d is the radial distance between the top of the said at least one lip and the base of the bristles of the brush seal, and
• drmax is the maximum relative radial displacement between the two elements of the turbomachine (10) rotating relative to one another.