Abstract: An electromechanical machine includes a stator fixed with respect to a housing structure and a rotor fixed with respect to a driven shaft. The stator includes a magnetically permeable core having a plurality of parallel winding slots containing conductive windings. Coilheads are located at opposite axial ends of the magnetically permeable core where the windings turn to extend down a parallel winding slot. The motor is equipped with an electrostatic shield arrangement to reduce capacitive coupling between the stator and rotor during operation. The shield arrangement comprises a grounded conductive layer separated from the conductive windings of the stator by an insulative layer of cured resin material. Preferably, the conductive layer may be formed of a conductive paint.

Abstract: A gear reducer housing includes mating front and rear shells, each formed with supports for bearings and rotating assemblies. The supports are located along a centerline of the housing shells and at two offset mirror image locations on either side of the centerline. The shell is at least partially surrounded by a peripheral flange for securing the housing shells to one another. Fastener apertures in each flange are formed to provide tolerance in the location of attachment fasteners. The flange includes fixturing pads allowing each shell to be fixtured once for a range of machining operations. Ports for lubricant permit the housing to be mounted in several angular positions.

Abstract: A circuit for and method of controlling transient currents on power conductors includes a voltage-controlled switch connected between one of the power conductors and a load. A turn-on circuit is connected to the switch to control the switch during a transition period in which the switch changes from a non-current conducting state to a conducting state in which a static current flow to the load can be maintained. The turn-on circuit controls turn-on such that the rate of rise and the peak amplitude of the current through the switch is limited during the transition period. A reset circuit also is connected to the voltage-controlled switch to reset the switch to a non-conductive state when the voltage between the power conductors drops out. The reset circuit is configured to reset the switch within a reset period having a duration that is shorter than the duration of the transition period.

Abstract: A multilayer circuit board or laminated circuit board for use in a motor controller is described. The multilayer circuit board is preferably utilized as a power substrate module. The power substrate module includes a mounting area provided in a recess, window or portion of the circuit board where the circuit board is only a single layer thick. The insulated mounting area is provided in a blind via in the multilayer circuit board. The single circuit board layer at the mounting area provides a heat conductive yet highly electrically insulated mounting area for receiving a heat sink. The heat sink can be mounted on a side opposite the electrical device. The heat sink may be standard heat sink or a copper coil directly soldered to the circuit board. The multilayer circuit board includes an enhanced conductive layer for receiving the surface mount device. The enhanced conductive layer preferably includes an insulative frame which holds copper slugs.

Abstract: An electric motor includes a stator having a plurality of conductive windings radially spaced about a central axis. A rotor is located radially inward up the stator and is rotationally fixed with respect to a shaft along the central axis. The rotor and the stator are disposed in a frame. A heater is in operative communication with the windings. A thermostat is in operative communication with the heater and is configured to activate and deactivate the heater responsively to a motor temperature.

Abstract: A switch assembly is provided that comprises a switch having a normally open contact and a normally closed contact which is electrically connected to the normally open contact and which is located either within the same housing as the normally open contact or a separate housing. The housing(s) may be mounted onto a latch assembly which, in turn, is mounted onto a switch operator, thereby closing the normally open contact. If the latch assembly becomes mechanically disengaged from the switch operator, thereby rendering the normally closed contact non-operational, the normally open contact will open, thereby opening the circuit to a machine performing a controlled function. The user, noticing the stoppage of operation, will then be alerted of a malfunction within the switch assembly.

Abstract: An electrical contactor includes an electromagnetic operator which may be powered by either AC or DC power. For use with AC power, a rectifier circuit converts AC waveforms to DC waveforms and applies the converted power to DC one or more DC coils. The rectifier circuitry applies DC power directly to a bus. A pair of coils may be used, such as separate pickup and holding coils. The pickup coil may be de-energized after an initial phase of operation. To permit rapid release of the holding coil, a control circuit interrupts an induced current path through the coil upon removal of power from the bus.

Abstract: The invention includes an autotransformer for converting three-phase AC power to twelve-phase AC power using only three coils (e.g., no primary or dead windings are required). The autotransformer includes three coils, each coil including a plurality of serial windings that together form a polygon. Twelve output nodes are provided between adjacent winding pairs, the windings sized and arranged such that adjacent output voltages are separated by 30 degree phase shift and such that output voltage magnitudes are essentially identical. In some embodiments step-up, step-down and unity gain input node sets are provided while in other embodiments unity gain and either step-up or step-down input node sets are provided. The invention also includes an isolation transformer configuration that uses a secondary configuration that is identical to inventive autotransformer configurations.

Abstract: A multi-element fluid sensor system having a distributed sensor configuration for determining the health state of a fluid. The sensor system includes at least two sensors for collecting data relating to a particular parameter (e.g., pH, temperature, electrical conductivity, chemistry, viscosity) of the fluid. The at least two sensors may be integrated onto a semiconductor base so as to provide for a micro sensor for in situ monitoring of the fluid. The system also includes a data fusion processor operatively coupled to the at least two sensors. The data fusion processor processes the fluid data to at least compensate for information fragmentation attributed to using the at least two sensors. The data fusion processor may condense the data, combine the data, evaluate the data and interpret the data.

Abstract: An improved conduit box assembly for a large electric motor permits placement of busbar units and other such components at various locations therein. The conduit box has a main box in which fixed mounting bases are installed. Preferably, four L-shaped mounting bases are provided, one located in each of the respective corners. The mounting bases are configured to permit attachment of removable terminal support members on which the busbar units or other components are carried. Each terminal support member is mounted in a desired location within the main box across a pair of opposed base elements. Preferably, the support members can be placed in any one of a plurality of rotational and axial positions.

Abstract: A movable contact assembly for contactors and similar devices includes a movable spanner or conductive element biased toward a conducting position by a biasing element. A housing partially surrounds the conductive element and the biasing element. The biasing element and exerts compressive forces against the housing and the conductive element. The assembly may be installed as a modular unit on a carrier which is displaced during operation of the contactor. The housing shields the biasing element from plasma, arcs and debris during operation of the device. Multiple conductive elements and corresponding biasing elements may be includes in each assembly.

Abstract: A method is provided for sensing and measuring an electrical current. The current to be measured is applied to a deflectable member in a sensing module in the presence of a magnetic field. Deflection of the member is detected as an indication of the current. A nulling current may be applied to one or more additional deflectable members mechanically linked to the deflectable member. Feedback or readout signals indicative of deflection of the members are monitored. The nulling current is modulated to drive the feedback signals to a desired level. The nulling current value is converted to a value representative of the current to be measured.

Abstract: In a method of measuring a current, the current is received at a winding and permitted to flow through the winding, which is wound about a core. The flow of the current through the winding induces a first magnetic flux that flows through the core and that tends to drive the core into saturation. The core is actively reset to prevent the core from being saturated at least during selected time intervals. The current is then measured during at least a plurality of the selected time intervals. In a particularly preferred embodiment, the winding is a primary winding and the resetting step includes applying a reset voltage to a secondary winding using a source that is coupled to the secondary winding. The reset voltage determines a rate at which a net magnetic flux that flows in the core changes in a direction away from saturation. Advantageously, the current sensing method has a tremendous dynamic range.

Abstract: A network system is provided for transmitting electrical power and data signals between a plurality of device nodes. The system includes a trunk cable in which a pair of dedicated power conductors and a pair of dedicated signal conductors are embedded in an insulative cover. Modular connectors are electrically coupled to the cable conductors at each device node. Each connector includes a base module and an interface module. The base module is attached to the cable via insulation piercing members and thereafter remains resident on the cable. The interface module is mated with the base module and serves to transmit power and data signals between the base module and a networked device. Several types of interface modules may be utilized interchangeably to permit the base module and cable to accommodate various types of devices and device drop cables.

Abstract: A shaft or shafts are connected to a rotor core of a dynamoelectric machine without the need for a central hole in the laminations of the core. The shaft is connected to the core by attaching the shaft to a rotor end plate (or forming the shaft and the end plate as a single unit) and connecting the end plate to the core at a distance away from the axis of the core. The rotor may have similar end plates at both ends, the end plates attached to each other and to the core by through studs or bolts that pass through holes in the laminations. The holes and the studs or bolts are evenly circumferentially spaced at a distance from the axis. The through studs or bolts are secured at either end, clamping the end plates with the rotor core between them. The rotor end plate provides support to the rotor end ring that forms part of the squirrel cage of the rotor core. The end plate includes a lip or other portion which restrains movement of the end ring in lateral and/or axial direction(s) as the rotor rotates.

Abstract: A technique is provided for sealing a bearing cavity in a rotating machine such as an electric motor. The bearing cavity is defined by annular elements on either side of an antifriction bearing set. Seals are provided on the sides of the bearing cavity and are secured to a support structure, such as the motor housing, and include elements which ride against the rotating shaft during operation. The seals exert a sealing force against the rotating element which results at least partially from internal pressure within the bearing cavity provided by a pressurized lubricant stream. The lubricant stream is provided in the form of an airborne oil mist.

Abstract: A simple voltage window sensing circuit including a current indicator, two Zener diodes and two digital transistors wherein the diode breakdown voltages are selected such that they define the upper and lower voltage limits of a voltage window, each diode causing a corresponding transistor to conduct when the breakdown voltage is exceeded, the indicator in series with a first transistor which is controlled by the diode which defines the lower limit and the transistors in parallel such that the first transistor only conducts when a voltage is within the window and hence the indicator only indicates when the voltage is within the window.

Abstract: A core configuration for use with an electromagnetic machine including first and second pluralities of laminations, each of the first and second pluralities having different properties and/or operating characteristics, the first and second pluralities interleaved together to form a core having desired core properties which are a combination of the properties of the first and second pluralities.

Abstract: A method and apparatus for determining the absolute position of a rotor in a permanent magnet synchronous machine (e.g. motor or generator) at standstill wherein short positive and negative voltage pulses are separately provided to each stator winding and the rate of current change with respect to time for each current is determined, the rates are used to determine general rotor position angle and thereafter are used to determine correction angle for correcting the general angle.

Abstract: A technique is provided for sealing a bearing cavity in a rotating machine such as an electric motor. The bearing cavity is defined by annular elements on either side of an antifriction bearing set. Seals are provided on the sides of the bearing cavity and are secured to a support structure, such as the motor housing, and include elements which ride against the rotating shaft during operation. The seals exert a sealing force against the rotating element which results at least partially from internal pressure within the bearing cavity provided by a pressurized lubricant stream. The lubricant stream is provided in the form of an airborne oil mist.