Westinghouse Electric Corporation

Michael D Hecht

Paul J Boone

Lyman J Petrosky

Herbert E Ferree

John M Driggers

Wenche W Cheng

Stephen M Ira

Robert D Senger

Robert P Vestovich

Thomas R Wagner

George A Savage

Raymond G Kelly, Jr

Michael H Canton

Bruce R Cox

Chris W Bach

Thomas J Donnelly

Tara D Mapson

Kurt K Lichtenfiels

Stanley F Niziol

Anthony Grieco

Steve J Orbon

A component maintenance system having a network linked to a data acquisition system, a data analysis system, a historical file of component design and inspection information, and a diagnostic system having the capability to perform structural analysis of discontinuities identified by the data acquisition system. The network nodes may be located apart from each other; for example in the maintenance of a nuclear power plant steam generator, the data acquisition system may be located in a high radiation area while the data analysis system is safely located away from the radiation areas. Furthermore, the diagnostic system and the file of component design and inspection history information may be centrally located and shared to support component evaluations being conducted in numerous geographic locations. Network communication facilitates the rapid evaluation of discontinuities, thereby permitting the inspection plan to be modified as the inspection results are obtained.

Component maintenance system

An improved robotic arm system for servicing the tubesheet located within the channel head of a nuclear steam generator is provided. The system includes a robotic arm whose shoulder and elbow joints are rotatable only in the plane parallel to the tubesheet in order to eliminate the imposition of cantileverly-induced torques on the electric motors driving these joints, as well as to minimize the possibility of mechanical interference between the arm and the walls of the channel head. Each of the motorized joint assemblies of the arm includes resolvers connected not only to the output of the drive train that moves the joint, but also to the drive shaft of the electric motor that drives the drive train, wherein the feedback signal generated by the resolver connected to the drive shaft of the electric motor is the primary signal used to modulate the amount of electric power conducted to the motor of the joint. Such a configuration advantageously results in smoother robotic arm movement. Finally, the control circuit assembly of the robotic arm system includes a control processing unit (CPU) which is capable of simultaneously driving not only the joint assemblies of the robotic arm, but also any computer-operated mechanisms associated with a variety of end effectors which the arm is capable of delivering. The CPU, power supply and other components of the control circuit assembly are installable in the containment area surrounding the steam generator in order to eliminate the number of cable penetrations through the containment walls that are necessary to operate the system.

Robotic system for servicing the heat exchanger tubes of a nuclear steam

An improved electric actuator is provided, having in association therewith a resolver. The actuator includes a stationary and a rotatable housing, and an electric motor within it. The electric motor drives the rotary housing through a speed reducing harmonic drive mechanism. The actuator has an opening in the rotary housing, and a cavity inwardly of the opening having a mating anchoring element connected with the stationary housing. A modular resolver is provided, of a shape and size to have a major portion of it occupy the cavity provided in the actuator, and having a mating part for engaging the mating part of the stationary housing, upon assemblage of the resolver to the actuator. A rotatable part of the resolver is secured to the rotary housing. A heat dissipation system is provided, including a fan mounted on a rotary member of the actuator and a closed circuit for the passage of air between the fan and a heat conductive plate forming a part of the stationary housing. Stability for the rotary housing is provided by widely spaced ball bearings supporting a rotary shaft extending from the rotary housing, the ball bearings being located at the maximum axial spacing within the stationary housing. In addition, an electromagnetic brake of lightweight construction is provided to prevent rotation of the rotary housing, and the resolver includes a coupling of the bellows type for elastic isolation from distortion of the parts, due to stresses between the fixed and rotary parts of the resolver.

Lightweight electric robotic actuator

Growing community of inventors

Hempfield Twp., Westmoreland County, PA, United States of America

Michael D Hecht