A conventional fan and/or compressor assembly includes rotor blades interspaced with static vane stages which occupy a duct which defines a path down which fluid being pressurised will pass. A gap is provided between the rotatable and static components to permit relative rotation. In order to optimise efficiency of the system, it is important to minimise this gap in order to limit leakage of the air being pressurised. Typically this is achieved by either designing the gap to be as small as possible and/or by the provision of a sealing member which extends across at least part of the width of the gap. Conventionally a thin metal sealing member is located in a groove in the stator vane platform. The sealing member obstructs the gas flow through the gap and is thin enough that, in the event of excessive relative axial movement of the stator vane and rotor blade, it is easily deformed without causing damage to the vane or blade.
However, since the edge of the groove in the platform in which the sealing member steps down to the sealing member, it will inherently introduce a discontinuity into the gas washed surface of the platform, thus introducing a disturbance to the flow. Also, in builds where a composite vane is used to reduce weight of the system, a groove in the platform will significantly reduce the strength of the vane and may result in composite structure coming apart. It should also be noted that the location of the sealing member is critical, since it must provide a seal without interfering with the gas flow over the platform. That is to say, it must occupy a location predefined in the design of the compressor and be neither too far inset or too proud of the gas washed surfaces of adjacent platforms. In the absence of a location groove, this is achieved using dedicated jigs, fixtures and tooling to which are expensive to produce and time consuming to use.
Hence a sealing means which can be easily located in a desired position on vane platforms is highly desirable.