Abstract: Cracks in the shaft of a reactor coolant pump adjacent a tapered end on which the impeller is mounted are removed by machining a circumferential groove in the pump shaft to a depth and an axial length which removes the cracks but does not extend into the tapered end of the pump shaft. A split ring fills the groove to an outer diameter which matches the outer diameter of the pump shaft. A thermal sleeve shrink fit over the split ring has internal annular ribs engaging the shaft and the ring to form an annulus which communicates with the pump chamber sufficiently to maintain a layer of substantially stagnant coolant over the split ring and the pump shaft at the pressure of the coolant being pumped.

Abstract: A thermal barrier for a nuclear reactor coolant pump includes a stack of pancake cooling coils encircling the pump shaft where it enters the pump chamber. This stack of coiling coils has an irregular peripheral surface formed by axially extending, diametrically opposed, inlet and outlet tubes which are circumferentially indexed for each pancake coil. The inner surface of a cylindrical cover has a complimentary inner peripheral surface formed by two sets of diametrically opposed cascaded steps so that the volume of the annulus between the coil stack and cover is minimized to reduce stratification of cooling water injected into the cover. A collar around the pump shaft at the opening in the end wall of the cover extends axially into the coil stack to prevent vortices produced by the spinning shaft from flowing across the end wall of the cover, while circumferentially spaced holes in the collar prevent significant alteration of the thermal conditions of the pancake coiling coils.

Abstract: An in-line, multi-stage pump powered by integral canned electric motors. At least two pump units are connected in series in a pipeline. Each of said pump units includes a hollow housing having a hermetically sealed stator mounted therein. The stator is electrically connected to a source of electrical energy. An impeller assembly that includes a tubular suction shroud and impeller is rotatably mounted inside the housing. The impeller assembly includes a hermetically sealed rotor which is mounted around the suction shroud and positioned inside the stator in operative association therewith. Energizing the stator rotates the rotor, which in turn rotates the impeller to pump fluid from the intake end of the housing to the outlet end of the housing. The subsequent pump units add pressure and/or maintains the pressure of the pumped fluid.

Abstract: A passively temperature actuated valve has a shape memory alloy (SMA) mechanism connected to a lever arm which engages the valve stem to actuate the valve against the biasing force of a valve stem biasing spring when the ambient temperature rises above the transition temperature of the SMA. The SMA mechanism can include an SMA rod, but preferably has a tube of shape memory alloy supported in couplings which allow ambient fluid to freely pass through the tube. A stack of Bellville springs concentrically mounted over the tube biases the tribe to the elongated condition when below the transition temperature. An optional latch latches the valve in the actuated position if it is required that the valve remain actuated when the ambient temperature falls below the transition temperature and the Bellville springs again elongate the SMA member.

Abstract: An auxiliary thruster for a marine vessel. The auxiliary thruster includes a submersible propulsion unit which has a shroud with a propeller rotatably mounted therein. A canned electric motor is mounted between the propeller and the shroud for rotating the propeller to create thrust. A propulsion unit deploying and rotating mechanism is mounted on the hull and on the propulsion unit. The propulsion unit deploying and rotating mechanism is operable to extend the propulsion unit out of the hull and retract it into the hull and to rotate the propulsion unit to direct the thrust generated thereby in any desired direction when the thruster is in the deployed position. When the thruster is retracted, it is positioned with a tunnel extending transversely through the hull. Rotation of the propeller while in the retracted position generates laterally directed thrust through the tunnel.

Abstract: A fluid pump powered by an integral canned motor includes a housing having a cylindrical passage extending therethrough. A sealed annular stator is mounted around the housing. An impeller assembly is rotatably mounted in the passage in the housing. The impeller assembly includes an axial flow impeller and a sealed rotor mounted around the periphery of the impeller. Bearings, including thrust bearings, are mounted between the periphery of the impeller assembly and the housing. A radial flow auxiliary impeller may be mounted on the impeller assembly to create a radial flow of water from the cylindrical passage in the housing to a peripheral fluid circulation channel between the impeller assembly and the housing. The auxiliary flow impeller pressurizes the peripheral fluid circulation channel.

Abstract: A water jet propulsor powered by an integral canned electric motor includes a hollow housing having a hermetically sealed stator mounted therein. The stator is electrically connected to a source of electrical energy in the vessel. An impeller assembly that includes a tubular suction shroud and impeller is rotatably mounted inside the housing. The impeller assembly includes a hermetically sealed rotor which is mounted around the suction shroud and positioned inside the stator in operative association therewith. Energizing the stator rotates the rotor, which in turn rotates the impeller to pump water from the intake end of the housing to the outlet end of the housing and adds velocity and head to the water to be discharged from the outlet end. The discharged water creates thrust which propels the vessel.

Abstract: A two-stage submersible propulsor unit comprises a shroud having a water inlet and a water outlet, a shaft assembly centrally mounted within the shroud, an upstream and a downstream propeller, each of which includes a separate hub rotatably mounted on the shaft assembly, first and second electric motors separately rotating the upstream and the downstream propellers. Each motor includes a rotor mounted around the outer periphery of one of the propellers and a stator mounted around the shroud, and first and second thrust bearing assemblies for absorbing the thrust load generated between the hubs of the first and second propellers and the shaft assembly. Both thrust bearing assemblies are contained within a housing located on the downstream end of the shaft assembly.

Abstract: A system is provided for deploying a propulsor unit from the hull of a water vehicle, such as a submarine. The system comprises an opening in a submerged portion of the hull that leads to a chamber for storing the propulsor unit, a cover for covering the hull opening to render the surface of the hull substantially continuous and fluid-dynamic, the cover having first and second sides, each of which conforms to the contour of the hull and the propulsor unit being mounted on the second side of the cover, and a pivotal mounting that hingedly connects the cover and the propulsor unit attached thereto across the opening in the hull for allowing the propulsor unit to move from a first stored position within the storage chamber to a second deployed position in the ambient water surrounding the hull. A drive assembly is provided for pivotally moving the cover and its attached propulsor unit between stored and deployed positions.

Abstract: The submersible propulsor unit of the invention comprises a cylindrical shroud having a water inlet and a water outlet, a propeller having a hub rotatably mounted within the shroud on a shaft, and an electric motor for driving the propeller that includes a rotor mounted around the periphery of the propeller, and a stator circumscribing the shroud, and a bearing assembly that includes means for circulating ambient water around the bearing surfaces to both lubricate and cool them. A stationary cover is detachably secured over the bearing assembly on the water inlet end of the shaft to provide easy access to the bearings in the bearing assembly The vane members that concentrically mount the shaft within the interior of the shroud are, in one embodiment, all connected on the downstream side of the propeller to reduce the cavitation and resulting noise when the propeller rotates. The magnetization of the rotor is provided by a plurality of permanent magnets for both improved efficiency, and lower noise.

Abstract: The submersible propulsor unit of the invention comprises a cylindrical shroud having a water inlet and a water outlet, a propeller having a hub rotatably mounted within the shroud on a shaft, and an electric motor for driving the propeller that includes a rotor mounted around the periphery of the propeller, and a stator circumscribing the shroud, and a bearing assembly that includes means for circulating ambient water around the bearing surfaces to both lubricate and cool them. A stationary cover is detachably secured over the bearing assembly on the water inlet end of the shaft to provide easy access to the bearings in the bearing assembly. The vane members that concentrically mount the shaft within the interior of the shroud are all connected on the downstream side of the propeller to reduce the cavitation and resulting noise when the propeller rotates. The magnetization of the rotor is provided by a plurality of permanent magnets for both improved efficiency, and lower noise.

Abstract: A pivoted pad bearing assembly of the Kingsbury type provides for leveling of bearing pads arranged in a circular array utilizing hydrostatic pressure rather than mechanical links. The leveling device is in the form of a hydraulic bearing support module having a variable volume hydraulic chamber. Pipe segments connect each hydraulic chamber to form a closed circuit and the circuit is completely filled with hydraulic fluid. Thereby, equal force will be exerted upon each pad at all times so that all pads will operate at an equal thrust load. The bearing assembly has particularly useful application in an integral motor submersible propulsor as a large diameter thrust bearing housed within an outer shroud of the propulsor at both upstream and downstream ends of a rotor mounted about the periphery of a propeller of the propulsor. By placing the thrust bearing within the shroud, greater thrust bearing surface areas can be obtained to handle larger thrust.

Abstract: A high-thrust, shock-resistant submersible propulsor unit comprises of a shroud having a water inlet and a water outlet, a shaft assembly centrally mounted within the shroud, and an upstream and a downstream propeller, each of which includes a separate hub rotatably mounted on the shaft assembly, first and second electric motors for independently rotating the upstream and the downstream propellers, wherein each motor includes a rotor mounted around the outer periphery of one of the propellers, and a stator mounted on the shroud around the rotor, and first and second bearing assemblies, each of which includes a thrust bearing disposed within the hubs of the upstream and downstream propellers in the shaft assembly, wherein the thrust bearings associated with the first and second bearing assemblies are located on opposite ends of the shaft assembly. Each of the bearing assemblies includes a removable cover which affords easy and separate access to the bearing contained in each.

Abstract: Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening.

Abstract: A flywheel assembly adapted to act also as a high inertia journal bearing in a canned pump or the like is composed of an annular core of heavy metal material which is hermetically sealed in a stainless steel casing formed by a number of enclosure pieces welded together along circumferential weld edges. The weld edges are specially configured by mating weld canopies provided on the respective pieces which minimize the potential for damage to the annular core during welding, and which act to minimize stress concentrations due to the welds and thermal expansion of the casing. An outer cylindrical shell of the casing is heat shrunk onto the outer core and grooves are provided in the outer surface of the annular core to axially secure the outer enclosure member to the core, and to ensure that thermal expansion of the cylindrical shell occurs substantially equally in each axial direction of the shell. The flywheel assembly includes radial and axial bearing surfaces provided on the outer casing.

Abstract: Heat pipes having predetermined configurations and positioned within the wedges and wedge retainers for maintaining the rotor field windings in position for efficiently collecting heat generated along the length of the rotor field windings and rotor surface and transporting this heat to the ends of the rotor where it is transferred to a coolant medium such as a gas or spray liquid are disclosed. The particular heat pipe positioning and configuration provides an optimal amount of heat transfer surface area for transferring heat from the wedge material to a volatile fluid within the heat pipe. Heat is thus efficiently transferred to the volatile fluid which changes the volatile fluid from a liquid phase to a vapor phase where the vapor flows at a high speed to a condenser section beyond the axial length of the rotor field windings where heat is dissipated from the volatile fluid to the cooling medium.

Abstract: A system is provided for deploying a propulsor unit from the hull of a water vehicle, such as a submarine. The system comprises an opening in a submerged portion of the hull that leads to a chamber for storing the propulsor unit, a cover for covering the hull opening to render the surface of the hull substantially continuous and fluid-dynamic, the cover having first and second sides, each of which conforms to the contour of the hull and the propulsor unit being mounted on the second side of the cover, and a pivotal mounting that hingedly connects the cover and the propulsor unit attached thereto across the opening in the hull for allowing the propulsor unit to move from a first stored position within the storage chamber to a second deployed position in the ambient water surrounding the hull. A drive assembly is provided for pivotally moving the cover and its attached propulsor unit between stored and deployed positions.

Abstract: Both a closed system and method for cooling a submersible propulsor unit for a water vehicle is provided for a unit of the type that includes a submersible motor having a shaft connected to a propeller, and a housing containing the motor. The system comprises a motor cooling assembly that includes a shaft seal for conducting the shaft outside of the housing while preventing ambient water from entering the housing, a liquid contained within the housing for cooling the motor, a heat exchanger for thermally connecting but mechanically isolating the liquid from the ambient water, an impeller (102) for recirculating the liquid through both the motor and the heat exchanger, and a bellows (128) for equilibrating any pressure differentials between the cooling liquid and the ambient water. A filter assembly (129) mounted within the bellows relieves any pressure differential that is not relieved by the bellows when ambient water pressure is greater than that of the cooling liquid in the housing.

Abstract: A stepping apparatus uses two gate elements driven by solenoid actuators to block a detector string as it is advanced to a gamma counter so that the string can be advanced at a controlled rate, one ball at a time. The gate elements each have two interconnected passages, one of which permits passage of the entire detector string, while the other permits passage of the cable but not the balls.

Abstract: A hydro-ball in-core instrumentation system employs detector strings each comprising a wire having radiation sensitive balls affixed diametrically at spaced positions therealong and opposite tip ends of which are transportable by fluid drag through interior passageways through which primary coolant is caused to flow selectively in first and second opposite directions for transporting the detector strings from stored positions in an exterior chamber to inserted positions within the instrumentation thimbles of the fuel rod assemblies of a pressure vessel, and for return. The coolant pressure within the detector passageways is the same as that within the vessel; face contact, disconnectable joints between sections of the interior passageways within the vessel facilitate assembly and disassembly of the vessel for refueling and routine maintenance operations.