General Electric Company

James B Archibald

True T Shih

Anthony F Armor

Frederick J Rink, Jr

James F Hopeck

Paul C Rasmussen

William L Darby

Thomas B Jenkins

Manoj Ramprasad Shah

Kenneth Gordon Herd

Richard Nils Dawson

Robert John Nygard

Steven L Adams

Kirk G O'Brien

Donald R Albright

David A Noel

James V Eats

Frank R Landrio

Ernest L Moore

Barry L Karhan

Henry F Sage

Kim H Crounse

Reuben Weinstein

In a dynamoelectric generator, a low-resistance electrical contact is provided by using a spring below the rotor slot wedges to bias the wedges against the overlapping retaining rings. This biased contact between the wedges and retaining rings forms a conductive current path for high-frequency eddy currents induced on the surface of the rotor and retaining rings at all operating speeds and at rotor standstill. In addition, the spring reduces gauling between the rotor key slots, wedges and retaining ring.

Harmonic current path spring device between retaining ring and rotor

A connector design for connecting rotor coil end turns and an exciter/rectifier assembly to a rotor bore copper conductor in a dynamoelectric machine. The design includes a terminal stud or pin sized to be closely received in a telescoping manner in a cylindrical receptacle which is fixedly attached to the rotor windings. A similar cylindrical receptacle extends from the other end of the rotor toward the exciter/rectifier assembly. The stud or pin in each case is also modified to include grooves for accepting resilient, sliding electrical contacts so that a resilient electrical contact is obtained when the stud is positioned within the receptacle. The connector elements are also sufficiently rigid as to withstand shock, centrifugal forces at operational speeds, and rotation direction reversal, but which also allows sufficient radial and axial movement to accommodate coil movement associated with rotor temperature and speed changes while simultaneously maintaining a low resistance current path.

Resilient connectors for a generator/motor rotor

A flexible main lead connector design for connecting an end turn of a rotor winding of a generator/motor to a terminal stud. The connector includes a first elongate, radially directed, conductive member attached to the rotor winding and a second elongate conductor member connected to the centralized terminal stud. The first conductive member has an inverted 'T' shape with its base tapering from a relatively thick central portion to relatively thin outer portions. The second conductor member has a central 'T' shaped portion and two relatively thin peripheral band portions shaped to generally follow the side and lower top surfaces of the central 'T' shaped portion. The bands continue in a curved manner toward and join with the relatively thin outer portions of the first conductive member and thus form a flexible connector allowing relative movement between the first and second conductive members. The connector, however, also supports the flexible bands against centrifugal forces present at rotor operating speeds by the inclusion of the 'T' shaped portion of the second conductor member which is positioned to form a support cap for the bands.

Main lead connector for a generator/motor rotor

In a dynamoelectric generator, a low-resistance electrical contact is provided by a multilam or belleville spring mounted between the outer surface of the rotor body and an overlapping retaining ring. This contact forms a conductive current path for high-frequency eddy currents induced on the surface of the rotor and retaining rings at all operating speeds.

Multilam or belleville spring contact for retaining rings on

Cooling means are provided for directly cooling the bore bus bars which connect a direct current exciter such as a bore pack exciter to the field of an electric power generator. Two bore bus bars are separated by an insulating sheet have a circular cross section, and are surrounded by an insulating cylinder. The bore bus bars include an axially extending slot adjacent the insulation to form passageways through which cooling gas flows to directly cool the bus bars and pass through the generator to the cooling unit.

Direct cooled bore connector

A gas cooling system for a bore pack exciter for a power generator in which high velocity, colder cooling gas is obtained from the region within the generator where the entering cooling gas is impelled by the generator fan, and means to direct part of that cooling gas from that flow through the bore pack exciter before return to the interior of the generator for recycling through the cooling unit.

Bore pack exciter cooling system

A stator of a dynamoelectric machine is preassembled using guidance members which are disposed at a skew angle with respect to a central axis of the stator. The outer perimeter of the preassembled elements is then machined to form guidance elements disposed parallel to a central axis of the stator. Then, the preassembled elements are mounted in a frame on further guidance elements disposed parallel to the central axis of the stator. During final assembly, axial compression forces act parallel to guidance forces, whereby hanging up is avoided.

Method for producing a stack of laminations with skewed conductor slots

In a dynamoelectric machine having an annular stator core and a cylindrical rotor for concentric rotation therein, and defining a gap region between the rotor and the stator core, a baffle disposed in the gap region includes a shell member which circumferentially surrounds the rotor and includes a respective radial outwardly extending annular flange member at both its inner and outer axial end. An annular plate at the outer axial end abuts the axial outer flange and is radially adjustably secured to the stator. The axial inner flange comprises a flexible material, such as silicone rubber, and engages the stator in gas flow sealing relationship. An outer second passage disposed between the baffle and the stator is axially sealed off from the gap region by the flexible flange, thereby diverting gas in the outer passage to at least one coolant passage in the stator.

Coolant gas flow separator baffle for a dynamoelectric machine

A common neutral bus is formed in a lower frame extension of a large three-phase generator by disposing three sets of neutral current transformers within the lower frame extension and interconnecting the three phases downstream of the neutral current transformers to form an internal neutral bus. The neutral bus is connected to an external neutral transformer through a neutral terminal of small size and low cost. Clamshell clamps are provided in the internal neutral bus for isolating the neutral ends of the generator winding for test purposes. Rigid support of the current transformers and a hollow copper tube passing therethrough permits use of light and low-cost hollow copper tubing in place of the relatively substantial and expensive neutral terminals conventionally required.

Internal common neutral bus in large three-phase generator

A braid clamp for generator shaft voltage and current pickup employs a compound lever for forcibly locking clamping faces of a compound action clamping block into firm contact with a portion of a metallic braid. The metallic braid is thereby secured with a portion thereof in trailing contact with a surface of the generator shaft. Provision is made for holding a substantial free end of the metallic braid ready for use but secure from accidental contact with adjacent objects. The free end may be employed for contact with the shaft by reversing the braid or may serve as a supply of braid which may be fed between the clamping faces. The compound lever is quickly openable and closeable to reduce any risk to workers servicing the metallic braid in close proximity to the rapidly rotating generator shaft.

Braid clamp for generator shaft voltage and current pickup

A terminal plate is permanently affixed to a stator frame below the connector rings. High-voltage bushings are installed in the terminal plate at the user's site. Conducting bars are employed between each connector ring and its respective high-voltage bushing. Each conducting bar terminates at a short tangential distance from a connecting portion of its related high-voltage bushing. Domed flexible straps interconnect the conducting bars with the high-voltage bushings, the domed portions of the straps oriented to absorb relative motion engendered by tangential forces on the stator core and connector rings.

Generator stator frame with integral high-voltage bushings

A stator core for a dynamoelectric machine comprises a plurality of coaxially aligned annular module sections with axial cooling passages therethrough. The modules are spaced apart and fluid coupling means are disposed between the aligned axial passages in adjacent modules in a selective fashion to provide cooling flow paths which are both axially and radially directed.

Stator core with axial and radial cooling for dynamoelectric machines

A stator for a dynamoelectric machine preferably comprises a stack of modular sections, each modular section comprising an outer metallic cylinder formed from a plurality of metallic laminations arranged in a plurality of layers. Furthermore, the stator module comprises an inner nonmetallic cylinder formed from nonmetallic laminations having inwardly projecting teeth so as to define a plurality of slots along the inner circumference of the modular sections, the nonmetallic laminations being adhesively bonded to the outer metallic laminations. The stator modules of the present invention may be incorporated either in a conventional air-gap winding generator or employed in a superconducting rotor generator exhibiting high magnetic flux in the air-gap region between the rotor and the stator.

Air-gap winding stator construction for dynamoelectric machine

Terminal boxes for large dynamoelectric machines provide a housing for high voltage terminal bushings which connect the dynamoelectric machine with a power grid. The stray flux from the terminal bushings induces eddy and circulating currents in the terminal box walls and consequent heating of the walls. To limit wall temperatures water is circulated through sealed flow channels fabricated to the terminal box walls and in series with the terminal bushings flow circuit. A preferred wall construction comprises an outer wall of stainless steel clad carbon steel and an inner wall of stainless steel.

Liquid cooled terminal boxes

An integral nozzle-shield assembly for a gas-cooled dynamoelectric machine such as a large turbine-driven generator is described. The nozzle-shield assembly is formed of a non-conductive, non-magnetic material such as molded fiberglass and resin and serves to channel hydrogen gas between a heat exchanger and a rotor-mounted fan used to pump the gas through coolant passages in the dynamoelectric machine, and the assembly also provides a labyrinth seal over the fan blade tips. In one embodiment, the nozzle-shield assembly includes two 180-degree halves whose thickness varies circumferentially and which may be installed in a generator by bolting their outer edges to a stator frame member of the generator and bolting the halves together at the two radial joints between halves using flat metal plate connectors. Use of a material such as fiberglass and resin to form an integral nozzle-shield assembly results in a structure which is not susceptible to eddy current losses or damage due to arcing, and this integral assembly is readily fabricated and easy to install in a dynamoelectric machine.

Growing community of inventors

Schenectady, NY, United States of America

James B Archibald