Reparación de la cola de milano de la ranura de un rotor (TIL-1292)

MD&A brinda una solución permanente y económica para la atender la corrosión y agrietamiento potenciales de las superficies de las colas de milano de las ranuras del rotor de un generador.  La inspección y las reparaciones pueden llevarse a cabo tanto en su planta como en nuestro centro de reparaciones de turbinas y generadores ubicado en St. Louis, Missouri.

Crack indications located along the wedge loading surfaces are the result of a combination of factors. These include fretting created at the butt-ends of the field wedges, excessive starts / stops, and cyclic stresses resulting from rotor “bending” while on turning gear. Negative sequence current events have also been found to aggravate the effects.

Engineered Repair Alternatives
MD&A provides economic alternatives for addressing issues associated with generator rotor dovetail load surface cracking. MD&A’s methods meet all OEM requirements and include testing of critical regions which may be susceptible to cracking.

Recommendations for addressing these issues may vary depending on a variety of factors. The objectives of MD&A’s recommendations are:

• To provide reliable alternative repairs for our customers
• To meet or exceed OEM recommendations
• To provide inspection and repairs that are cost-effective, reliable, and meet the operating needs of the owner

MD&A Inspection Scope and Repair Options Include:

• Work can be performed at the owner’s site or in our St. Louis repair facility
• Remove retaining rings and slot wedges, as needed
• Visual inspection of all rotor dovetail surfaces and wedges
• NDE of wedge slot dovetail load surfaces using Eddy Current Testing
• Replacement of steel wedges with newly designed aluminum wedges which incorporate larger end radii
• Redesign of wedge lengths when appropriate to move the location where fretting can occur
• Machining of the affected load surface areas to remove indications, if any, and/or provide increased reliability when appropriate

Read our case study example:

Field Rewind with a Rotor Slot Dovetail Repair

Obtener más información sobre las demás reparaciones de generadores que ofrece MD&A.