Westinghouse Electric Corporation

The United States of America as Represented by the Secretary of

Westinghouse Electric Company LLC

Charles D Bice

Clifford H Campen

David J Janocko

Judith E Hodgson

Bruce A Howard

John H Cooper

Richard E Salnick

Nick Tallos

Glenn Quinty

Mark H Emerson

Paul C Gaberson

Michael L Fenger

A thermally actuated shutdown seal for a rotating shaft having a narrow annular fluid flow path surrounding the shaft. The seal surrounds the shaft with the annulus therebetween during normal operation and constricts against the shaft when the shaft slows or stops rotating. The annulus is maintained open during normal operation by a spacer interposed between opposing ends of a split ring. When the shaft stops rotating, the temperature of the annulus rises, which actuates removal of the spacer from the split ring constricting the split ring against the shaft blocking the annulus. The blocked annulus causes a pressure differential across the seal which urges a polymer seal ring, downstream of the split ring against the shaft which seals the annulus. In one embodiment, the spacer is formed of a meltable material. In a second embodiment, the spacer is removed from the split ring by a thermally responsive actuator.

Thermally activated shutdown seals for rotatable shafts

A system diagnoses the operability of a rotating electrical apparatus such as a reactor coolant pump (RCP) motor. The RCP motor includes a rotatable shaft, a stator, a bearing assembly and a bearing insulator. The bearing assembly electrically contacts the rotatable shaft and the bearing insulator at least partially electrically insulates the rotatable shaft and the bearing assembly from the stator. The system includes a shaft transformer and voltage source for inducing a voltage in the rotatable shaft; a variable resistor in parallel with the bearing insulator having first and second resistances; an analog-to-digital converter for sensing a first voltage associated with the first resistance and a second voltage associated with the second resistance; and means for determining the operability or the impedance of the bearing insulator from the first and second voltages and the second resistance.

Method and apparatus for diagnosing bearing insulation impedance of a

An online system for diagnosing operability of a rotating electrical apparatus includes sensors producing electrical variables corresponding to operating conditions of the apparatus, data converters for converting the electrical variables to digital values, a comparator for comparing the values to corresponding predetermined baseline values of the apparatus and producing a corresponding comparison value, and a signalling mechanism for outputting signals related to a period of predicted operability of the apparatus whenever the comparison value exceeds a corresponding predetermined deadband value. The operating conditions may be non-electrical operating conditions, such as a condition of a lubrication system or a bearing of the apparatus. Alternatively, the sensors may sense electrical insulation non-thermal parameters during operation of the apparatus, in order to produce signals related to the operability of an insulator of the apparatus. The system may have a local processor for performing the comparisons and signaling. Alternatively, the system may include an intermediate data storage and communication mechanism for storing and communicating the sensed values to a remote processor. The processor may also trend the values with respect to time and determine a derivative of a sensed value. The apparatus may be a motor operating in a hazardous environment, such as a reactor coolant pump (RCP) motor operating in a nuclear containment vessel.

Online diagnostic system for rotating electrical apparatus

An auxiliary flexible vacuum seal for preparing a reactor coolant pump for vacuum degasification of the reactor coolant system employs a flexible boot member having a pair of longitudinally-displaced opposite open end portions and a pair of side-by-side longitudinally-extending side portions in the form of flanges defining a split in the boot member along a side thereof and extending between the open end portions for allowing flexing of the boot member between open and closed side configurations to permit its installation and removal on and from the pump. The seal also employs clamping brackets and fasteners for releasably and sealably clamping together the flanges of the boot member at the split to retain the boot member in its closed configuration. The seal further includes a pair of circumferentially-extending sealing portions formed integrally on the interior of the boot member at opposite open end portions thereof for sealably engaging the pump when the boot member is flexed to its closed configuration to thereby permit generation of a vacuum seal condition between the boot member and the pump. Preferably, a boot support member is disposed within the boot member between the boot member and the pump for supporting the boot member when in its closed configuration.

Method of preparing a reactor coolant pump for vacuum degasification of

A pump has a pair of seal parts which are arranged to undergo axial translatory motion and a seal assembly associated with the seal parts. The seal assembly includes an annular liner disposed within a groove in one seal part and projecting therefrom toward a cylindrical surface of the other seal part, and a flexibly resilient annular O-ring disposed within the groove between the cylindrical surface of the other seal part and a surface of the liner which extends generally parallel to the cylindrical surface of the other seal part. The O-ring is seatable on a radial surface of the annular liner and projects from the groove farther across a gap between the seal parts than the liner and into contact with the cylindrical surface of the other seal part such that the O-ring is capable of rolling on the cylindrical surface of the other seal part and slipping on the radial surface of the annular liner upon translatory movement of the seal parts relative to one another.

Reactor coolant pump having improved dynamic secondary seal assembly

A pump includes an annular runner and annular seal ring mounted for undergoing relative rotation. The runner includes an annular support member and an annular faceplate member. The faceplate member has a sealing surface and is mounted by a clamp ring member to the annular support member. The support member includes an annular body having outer and inner circumferential edges, an outer raised circumferential rib defined on the body adjacent to its outer circumferential edge at one side of the support member for engagably supporting the faceplate member at an adjacent side thereof, an inner raised circumferential rib defined on the body adjacent to its inner circumferential edge at the one side of the support member for retaining a separate O-ring between the adjacent sides of the faceplate and support members, and an annular recessed cavity defined in the body at the one side of the support member between the outer and inner ribs for substantially spacing the faceplate member from the support member at the adjacent sides thereof to thermally insulate the faceplate member from the support member. Also, a middle raised circumferential rib is defined on the annular support member body between the outer and inner ribs for defining a seat groove with the inner rib for the O-ring.

Reactor coolant pump having thermally stabilized hydrostatic sealing

Reactor coolant pump auxiliary flexible vacuum seal for reactor coolant

An improved bi-switch construction is provided having an interrupting device arranged in electrical parallel relation therewith so that the circuit through each of the two switches is made through the interrupting device, and, subsequently, the interrupting device is shorted out in the closed-circuit position of the particular switch being operated. During the opening operation, again the interrupting device is brought into play so that a parallel electrical path is provided in shunt relationship to the particular switch being operated through the interrupting device, the interrupting switch assuming the burden of interrupting the circuit; and subsequently the particular switch being operated provides an isolating gap from the interrupting device. The arrangement is particularly desirable when two three-phase switches have a common leg, or terminal, to which one end of the interrupting device may be electrically attached, so that either switch may be operated with the interrupting device serving as a common means for both switches. An improved overcenter spring mechanism is provided for operating the interrupting device in both the closing direction and also in the opening direction for quick-make and quick-break operations of the interrupting device. In one arrangement, the movable contact member of each switch may comprise a rotatable movable blade, which first makes contact with an auxiliary terminal of the interrupting device, while simultaneously the overcenter spring device of the mechanism for operating the interrupting device is being charged. Further rotational movement of the movable rotatable blade of the particular switch effects, through the overcenter spring device, quick closing of the interrupting device, and further rotation of the movable blade effects a bypassing of the interrupting device, so that in the closed position of the particular switch being operated the interrupting blade effects conduction of all of the current to the main terminals of the particular switch being operated to the exclusion of the interrupting device.

Bi-switch construction having an auxiliary interrupting device

An improved electrical cable coupler incorporates rotatable protective covers on its plug and socket members to automatically protect the plug and socket contacts against contamination when the plug and socket members are disconnected and to allow the contacts to be electrically engaged when the plug and socket members are connected together. Each protective cover includes one or more openings which correspond in number and location to the electrical contacts on the plug and socket members. Each cover is rotatable between a protective position in which its openings are out of alignment with the respective contacts to provide protection against contamination and an operative position in which the openings are aligned with the respective contacts to expose the contacts for electrical engagement. The protective covers are adapted to interlock when moved into face-to-face engagement so that, by twisting the plug and socket members in opposite directions, the cover openings are moved into registration with the contact elements to allow electrical engagement therebetween. At least one of the protective covers is slidably mounted to permit relative axial movement of the plug and socket members to bring the contacts into electrical engagement.

Electrical cable coupler with rotatable protective covers

A cable tap assembly for connecting a tapping concentric cable to a high-voltage energized concentric cable. The tap assembly includes a two-piece housing having openings through which the cables extend. The tapped cable extends through two of the openings, and the tapping cable extends through a third opening. A fourth opening in the housing permits access for engaging a clamping assembly with the center conductor of the tapped cable. The clamping assembly includes two hinged members having knife contacts thereon. When the hinged members are forced together, the knife contacts pierce the insulation and make contact with the center conductor of the tapped cable. The tapping cable is electrically connected to the clamping assembly. A liquid insulating material is injected into the housing and allowed to solidify. The housing and the clamping assembly may first be positioned around the grounded portion of the tapped cable and then moved over to a prepared ungrounded portion of the tapped cable. When in position, the clamping means is tightened to make contact with the center conductor.

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Clinton Twp., Butler County, PA, United States of America

Charles D Bice