General Electric Company

James R Pedersen

Richard J Keck

Edmund E Kazmierczak

Vincent G Terry

Dennis R Ulery

Duncan N Walker

Brian E Gott

Gerald Richard Crawmer

David M Parker

Robert G Trechel

Paul F Murley

A process of manufacturing a steam turbine bucket having water droplet erosion resistance including the steps of:

Process for producing turbine bucket with water droplet erosion

Disclosed is a rotor body for an electric machine having slots for windings and slot keys with wedges for retaining the windings in the slots. The slot keys contain elongated spring strips underlying an amortisseur, in turn, underlying the wedges in the slot keys. The spring strips bias the amortisseur and wedges radially outwardly. Thus, the wedges lie in sufficient, low-resistance, efficient electrical contact with the rotor body at start-up and during low rotor speeds to prevent arcing and localized heating along the interfaces of the rotor parts otherwise resultant from induced surface currents at start-up and low rotor speeds. At the rotor ends, the spring strips bias the amortisseur ends radially outwardly into efficient electrical contact with retaining rings at opposite ends of the rotor body. A tool is also provided having a main arm, a pair of pivotally mounted dogs for engagement in the slot key and straddling the external surface of the slot key, respectively, whereby the tool may be fixed in axial position along the slot key by pressure on the main arm. A second pivotal arm carries a wedge-engaging head whereby the lever is fixed in the slot and the second arm drives the wedge longitudinally into axial position in the slot key.

Apparatus affording efficient electrical contact between rotor surface

A tool for applying slot wedges having a main arm, a pair of pivotally mounted dogs for engagement in the slot key and straddling the external surface of the slot key, respectively, whereby the tool may be fixed in axial position along the slot key by pressure on the main arm. A second pivotal arm carries a wedge-engaging head whereby the lever is fixed in the slot and the second arm drives the wedge longitudinally into axial position in the slot key.

Tool for applying slot wedges

For use in a pressure fed or flood lubricated bearing, there is disclosed a shaft load-bearing element (e.g., the thrust plate in a tapered land thrust bearing) preferably comprising three metallic layers including an inner layer adjacent the shaft surface of metal possessing good bearing properties; an outer layer of structural steel to provide rigidity; and an intermediate layer of copper or copper alloy sandwiched between the inner and outer layers to provide good thermal properties. The metallic layers of such a trimetallic bearing element are metallurgically bonded at the interfaces between layers to enhance heat transfer. Advantageously, a shaft load-bearing element according to the invention is substantially free from distortion and damage during handling and avoids elevated temperature problems. A load-bearing element according to the invention may be fabricated as a tilting pad for use in a journal bearing, as a thrust plate for a tapered land thrust bearing, or as a tilting shoe for a thrust bearing.

Trimetallic bearings

A copper alloy welding filler for use in arc welding copper to produce sound welds with good mechanical strength and high electrical conductivity is disclosed. The filler consists essentially of a zirconium-boron copper alloy filler metal wherein the concentration ratio of zirconium to boron is at least about 4 to 1; the minimum concentration of boron is about 300 PPM; and the concentration of zirconium is a maximum of about 6000 PPM. The minimum level of about 300 PPM boron on a weight basis eliminates porosity in the weld; while zirconium below about 6000 PPM is effective to eliminate weld cracking without having a detrimental effect on the electrical conductivity.

Growing community of inventors

Schenectady, NY, United States of America

James R Pedersen