Temperature activated expanding mineral shim

摘要

A method and apparatus for securing or attaching a rotor blade with a turbine rotor cavity by disposing an expanding material between the blade root and the cavity walls. The expanding material comprises a naturally occurring mineral which expands to a great degree when exposed to elevated temperatures. The expanding material may be provided in the form of shims made directly from the expanding material or made from a composition of the expanding material and a binder such as a polymer or elastomer. Alternatively, the expanding material may be provided in the form of a liquid vehicle applied to surfaces of the cavity walls. The expanding material is located at specific positions within the cavity to urge certain surfaces of the blade root against certain surfaces of the cavity walls. In this manner, the blade can be forced into a tight fit and an aligned position, with respect to the rotor, upon expansion of the expanding material.