DYNAMOELECTRIC MACHINE SLOT WEDGES WITH ABRASION RESISTANT LAYER

摘要

During lifetime of a large dynamoelectric machine the wedges may shrink enough not to prevent loosening of the restraint applied to the conductors, thereby, permitting development of conductor vibration. This problem is solved by a dovetail wedge (34) for retaining conductor bars (18, 16) in stator slot (14) of the large dynamoelectric machine includes an embedding surface layer (48a, 48b) on surfaces thereof which contact the lamination surfaces in dovetail slots (30) of a stator. The embedding surface layer (48a, 48b) permits the embossing thereof by irregularities of the surface of the laminations (12). A range of thicknesses for the embedding layer (48a, 48b) provides sufficient protection against abrasion and a sufficient lubricity during wedge installation without being so thick that long-term dimensional instability may permit loosening of the conductor bars (18, 16). The embedding layer may (48a, 48b) is preferably a natural fiber and most preferably a woven or non-woven cotton fiber.