Abstract: A combined steam condenser and liquid-to-liquid heat exchanger has an outer shell forming an enclosure within which a first plurality of tubes are supported at opposite ends by tube sheets to provide a steam condenser. Within the outer shell an inner shell having a heat exchange liquid inlet and outlet contains a second plurality of tubes providing a heat exchanger. In one embodiment a first head is affixed to one end of the outer shell and cooling liquid introduced into that head passes through the second plurality of tubes and part of the first plurality of tubes to a second head at the opposite end which directs the cooling liquid through an upper portion of the first plurality back to the first head. The cooling liquid is then directed from the first head through a lower part of the first plurality of tubes toward the second head where it is discharged through an outlet.

Abstract: A marine propulsion unit supported from a vessel by a strut contains an electric motor within a housing and a forward propeller driven by the electric motor and having a diameter larger than that of the housing. Hydrodynamic vanes projecting from the surface of the housing counteract tangential flow generated by the forward propeller. An aft section with a pair of counter-rotating blade rows driven by the electric motor is mounted at the rear of the housing and including a shroud surrounding the aft blade rows. The shroud is spaced from the housing so as to receive the boundary layer of liquid passing along the surface of the housing to inhibit cavitation and improve efficiency. Rearward portions of the shroud are movable to form a clamshell causing a reversal of the flow of the liquid passing through the shroud.

Abstract: A multi-channel motor winding configuration providing low harmonic distortion and a PWM inverting controller for this type of winding configuration are disclosed. The motor winding configuration includes a plurality of individually insulated conductors wound in a group through the stator slots of a synchronous or induction type alternating current (AC) motor. Depending on the winding configuration, the group of conductors may constitute a portion of or the entire current carried by one phase of a single or polyphase motor. The PWM controller for this type of winding configuration connects each conductor in the group to its own dedicated set of power switching devices in an H-bridge configuration. The H-bridge configuration is powered by a direct current (DC) or rectified AC source.

Abstract: In the embodiment described in the specification, a high temperature wet filament winding arrangement has a wet bath containing a resin at a temperature above 500° F. and filaments drawn from a spool rack are passed through the wet bath and then through a heated comb which maintains the temperature of the filaments above 500° F., after which the filaments are passed through a heated passage controlled to maintain the temperature above 500° F. A winding eye, also heated to maintain the filament temperature above 500° F., directs the heated fibers onto a mandrel where they are wound in uniform layers into the form of a final product. A mandrel heater heats the mandrel to which the fibers are being applied so as to maintain a uniform temperature above 500° F.

Abstract: In the embodiments described in the specification a metal heat transfer cold plate has two sets of parallel coolant passages extending between opposite end surfaces and non-metallic headers made of electrically insulating material are attached to the opposite ends of the metal plate. One of the headers provides an inlet to one set of coolant passages and an outlet from the other set of coolant passages and the other header provides fluid communication between the two sets of coolant passages. The headers are affixed to the cold plate by adhesive or by a snap-in connection having a sealing gasket between each header and the cold plate and the assembled cold plate and headers are insulatively supported by mounting feet attached to the electrically insulating headers.

Abstract: In the propulsion arrangement for an axisymmetric vehicle described in the specification, four propulsion modules are removably mounted at the rear of a vehicle in symmetric disposition about the vehicle axis, each module having an inlet section at its forward end which draws in the vehicle hull boundary layer without separation from the vehicle hull and supplies it uniformly to a rotating blade section driven by a rim drive motor. Control vanes for the vehicle are mounted between adjacent pairs of propulsion modules.

Abstract: In the external electric drive propulsion module arrangement described in the specification, two parallel propulsion units are mounted in a housing affixed beneath the stern of a ship and having a surface contour conforming to the contour of the adjacent surface portions of the ship's hull. Each propulsion unit is disposed substantially horizontally to provide maximum propulsion efficiency and has a rotating blade section for driving water rearwardly from an inlet and a fixed blade section following the rotating blade section. The inlet receives water from a wraparound array of screened intake openings near the forward end of the module housing which draws in the surface boundary layer of the ship's hull. In addition, vertical vanes are affixed to the stern of the ship to straighten the flow of water from the propulsion units.

Abstract: A marine power distribution arrangement includes a turbine-driven AC generator which supplies AC power at a frequency of 240 Hz through a switchgear unit to a transformer and a first power converter by which the power is converted to a variable frequency, variable voltage AC output for ship propulsion and to a second power converter by which the AC power is converted to a fixed voltage, fixed AC frequency or DC power to supply the ship service loads. A battery backup power supply may be switched in an emergency. In another embodiment four turbine-driven AC generators and two emergency power supplies are provided to drive two propulsion shafts as well as to supply the ship service loads.

Abstract: A marine power distribution arrangement utilizes generators driven at standard or higher than normal speeds and/or having a number of poles to produce electric power at a standard 50/60 Hz frequency or substantially higher than the standard 50/60 Hz frequency, such as 400 Hz. Each generator is a multi-phase, multi-circuit generator supplying isolated outputs on a plurality of lines to a propulsion power converter having isolated inputs to provide variable frequency, variable voltage power to a ship propulsion motor and to a service power converter to provide ship service power at a standard AC frequency or DC and at standard voltage for a service load. With this arrangement, power conversion transformers can, for the most part, be eliminated, thereby reducing the size and weight of the distribution system.

Abstract: In the embodiments described in the specification, a SWATH vessel has a superstructure supported by strut members from a pair of pontoons and each pontoon has a propulsion module removably attached to the rear end of the pontoon. The propulsion module has a self contained propulsion system including a module body with a longitudinal water passage, a rim drive electric motor, a row of rotatable blades, and an inlet opening at the forward end of he cowl member which is arranged to draw in the boundary layer of water flowing along the pontoon to which the propulsion module is attached. Spaced vanes are provided at the inlet opening to block objects from being drawn into the longitudinal passage.

Abstract: A marine power distribution arrangement utilizes generators driven at standard or higher than normal speeds and/or having a number of poles to produce electric power at a standard 50/60 Hz frequency or substantially higher than the standard 50/60 Hz frequency, such as 400 Hz. Each generator is a multi-phase, multi-circuit generator supplying isolated outputs on a plurality of lines to a propulsion power converter having isolated inputs to provide variable frequency, variable voltage power to a ship propulsion motor and to a service power converter to provide ship service power at a standard AC frequency or DC and at standard voltage for a service load. With this arrangement, power conversion transformers can, for the most part, be eliminated, thereby reducing the size and weight of the distribution system.

Abstract: An electric motor housing including a metal internal hub and composite material reduces weight, reduces motor vibration transmission, increases mechanical damping, improves corrosion resistance and improves electrical performance.

Abstract: In the embodiments described in the specification, a stator for an electric motor has an outer ring member made of resin material and supported from a frame by stator caps and a flanged inner composite ring member made of resin material which receives a steel band. Laminations and coil windings are mounted inside the steel band and an outer wrap of resin material encapsulates the steel band, laminations and coil windings. A rotor arrangement includes a steel hub surrounded by a disk-shaped member made of resin material and having inner and outer rings connected by radial arms. A non-ferromagnetic steel band surrounds the peripheral surface of the disk-shaped member and laminations and magnets or coil windings are positioned on the band and are encapsulated by an outer wrap of resin material.

Abstract: In the embodiments described in the specification, a power converter unit contains a series of enclosures mounted on a platform which is supported from a ship's hull structure by isolation mounts. Each enclosure includes power conversion modules and is supplied with power cables, cooling liquid pipes and control lines from a panel forming a back wall of the enclosure. The power converter modules are supported in the enclosure for displacement out of the enclosure for inspection and testing and flexible power cables, cooling liquid pipes and control lines are provided to facilitate testing and inspection.

Abstract: In the parallel resonant DC link inverter described in the specification, a DC voltage is applied to a plurality of semiconductor switches to provide an AC driving voltage for an AC motor by way of an LC tank circuit containing a nonlinear capacitance device having an antiferroelectric material as its dielectric. As a result of the increase in capacitance with increased voltage, the voltage peak of the link voltages produced by the circuit is reduced without a corresponding reduction in the volt-second product applied to the motor load.

Abstract: A high pressure corrugated plate-type heat exchanger includes a plate pack consisting of stacked corrugated plates having seals between adjacent plates contained in a high pressure enclosure. The seals act as the primary arrangement for containing the high pressure fluids supplied to the spaces between the plates and the high pressure enclosure provides resistance to high pressures applied to the seals from the fluids in the spaces between the plates or in port holes extending through the plates. The high pressure seals comprise either a captive O-ring type seal or a welded joint between the plates, or combinations of both types of seal. In one embodiment, a compression block is inserted between the plate pack and the end of the high pressure enclosure to transfer pressure from the end of the enclosure to the plates of the plate pack and thereby compress resilient seals disposed between the plates to a desired degree.

Abstract: An electric motor housing is made by press-forming a composite material on a metal cylinder and machining passages in the press-formed material. This reduces weight, reduces motor vibration transmission, increases mechanical damping, improves corrosion resistance and improves electrical performance.

Abstract: A high voltage, single-stage variable speed motor power supply utilizes direct AC-to-AC converters that do not have any intermediate DC link, along with a multi-level, multi-phase, multi-circuit variable speed motor drive and a motor in which a stator is wound with a number of multi-phase circuits. Each multi-phase circuit includes semiconductor switches arranged in drive switch pairs which are operated to produce an effective DC supply with the switches being controlled so that the most positive line-to-line source voltage is utilized for the inversion process.

Abstract: A method and arrangement for propelling fluidborne vehicles is disclosed that results in reduction in the overall form drag of certain classes of vehicles. The method and arrangement consists of using a propulsion system with an inlet that circumscribes the transition region between a forebody section containing the widest part of the vehicle and a tapered afterbody section of the vehicle to remove fluid from the viscous boundary layer that is generated by the forward portion of the vehicle, and accelerates this boundary layer fluid through a propulsion system in the afterbody portion of the vehicle. Removal of boundary layer fluid can reduce momentum losses which occur in the wake created by various classes of vehicles.

Abstract: In the direct current circuit interruption arrangements disclosed in the specification, a solid state circuit interrupter interrupts the connection in a circuit path between a power source and a load. The stored energy in the circuit is dissipated in a resistive commutation circuit by using controllable power semiconductors such as Insulated Gate Bipolar Transistors to increase resistance between the terminals of the circuit interruption arrangement. An in-line power semiconductor switch acts as the circuit disconnecting device and is shunted by a resistive commutation circuit consisting of a plurality of solid state commutation switches and resistors in various configurations which act to dissipate the energy. In one embodiment the solid state switches in the commutation circuit are connected to a common circuit interrupter terminal and to a resistor through a series of taps on the resistor and the resistor is connected to the other circuit interrupter terminal.