Abstract: A communication system for power monitors and the like includes a plurality of communication nodes connected in series. A technique is provided for automatically detecting the status of the system, including the need to configure the communication nodes or identify the presence and location of a fault. Further, configuration of the nodes is automatically performed as required, and the location of faults is visually represented to assist an operator.

Abstract: An auxiliary switch provides an output or feedback signal indicative of the position or logical state of a contactor, disconnect or other principal device to which it is coupled. The switch is formed as a modular unit which can be fixed directly to the principal device, and is actuated by movement of elements within the principal device. An optical switch set within the auxiliary switch includes an emitter and detector pair aligned in mutually facing relation. An actuator is movable with the principal device and supports an optical shield. The actuator displaces the shield between a position clear of the optical path and a position interposed between the emitter and detector to change the state of the auxiliary switch. A power supply circuit may be housed within the switch for supplying power to the optical switch and to output circuitry. The device is particularly tolerant to contamination and can reliably output low level logic signals indicative of the state of the principal device.

Abstract: A brushless DC motor drive is disclosed which includes drive and control circuitry incorporated into an integrated drive unit. The drive circuitry includes a ground offset or signal conditioning circuit which receives command input signals from a command device and corrects for variations in ground potential between the power source and to the drive. The corrected command signal is used for closed-loop velocity control of a brushless DC motor. The signal conditioning circuit also provides a reference voltage signal for use by a controller which controls the drive circuitry. The command input signal is also applied to an energy conservation circuit. The circuit applies power to the control circuit only when the command is above a preset threshold. When the command is below the threshold level, power is interrupted to the control circuit to reduce the energy consumption of the system.

Abstract: An elastomeric coupling system for securing axially aligned driving and driven shafts includes a pair of hubs coupled to one another by an annular flexible coupling element. The hubs are fixed to respective driving and driven shafts, and the coupling element is then secured between the hubs by anchoring assemblies. Each anchoring assembly includes anchoring members which are fixed to respective hubs by fasteners received in the hubs. The fasteners are oriented generally transverse to the aligned axes of the shafts, providing ready access for installation and servicing. As the anchoring members are secured about the hubs, axial and radial loads are exerted on peripheral beads of the coupling element to produce retaining forces sufficient to withstand considerable torsional loading during use.

Abstract: A bearing assembly includes an inner ring assembly defining a bore for receiving a shaft, and an outer ring assembly disposed radially outward from the inner ring assembly. A plurality of rotatable bearing elements are disposed between the inner and outer rings and permit the rotation of the shaft and inner ring relative to the outer ring. An annular member extends from the outer ring assembly radially inward toward the inner ring assembly. The annular member is secured to a housing surrounding the outer ring and axially bounds an area between the inner ring and the outer ring in which the plurality of rotatable bearing elements are disposed. A first seal is disposed outside the bearing area to seal a chamber between the annular member and the inner ring. The first seal permits egress of lubricant from the chamber but inhibits ingress of foreign matter therein.

Abstract: A modular structure for attachment to a rail includes securement members received and supported on either side of the rail. The rail includes a support web and parallel side flanges. The structure is constructed from a molded plastic base unit to which metallic securement members are assembled. The base unit preferably includes a rigid side and a flexible side. The securement members are substantially identical to one another, facilitating manufacturing and assembly, and reducing the number of different parts in the final module. The securement members each include v-shaped slots for engaging the side flanges of the rail. The base unit may be configured as a blank end unit, or may include features for creating terminal blocks, I/O blocks, switches, circuit board supports and the like.

Abstract: A structure for mounting a rotating machine element, such as a drum pulley, idler, roller or the like includes first and second bearing sets secured to first and second end disks of the rotating member. The first bearing set is secured to a stationary shaft by means of a locking assembly. The locking assembly includes a wedge-shaped sleeve or adapter which is secured between the inner race of the first bearing set and the stationary shaft. During installation of the locking assembly, the second bearing set remains slidable along the shaft, thereby avoiding pre-loads or stresses in either bearing assembly or the components of the rotating member. Once the rotating member has been fixed in a desired position along the shaft by means of the locking assembly, a retaining element may be placed adjacent to the second bearing set. The structure may be easily disassembled by the reverse process.

Abstract: A circuit interrupter provides a conducting path between two conductors and interrupts the conducting path in response to overcurrent conditions in the conductors. The interrupter includes a magnetic core around which the conductors are disposed. Each conductor is electrically coupled to an arc runner and a spanner is biased into contact with the arc runners to compete a conducting path between the conductors. A secondary response mechanism is provided adjacent to the core and includes arms extending around the core and a magnetic body. In response to overcurrent conditions of a first magnitude the body of the secondary response mechanism is attracted to the core causing the arms to displace the spanner out of contact with the arc runners. In response to overcurrent conditions of a second magnitude, such as due to direct short circuits, the spanner is repelled rapidly to a non-conducting position and the secondary response mechanism is attracted to the core to hold the spanner in the non-conducting position.

Abstract: A composite bearing housing includes a molded plastic body in which planar reinforcing elements are embedded. The reinforcing elements may be flat or shaped, such as in frustoconical or other configurations. The plastic body is molded around the reinforcing elements and may be formed in any of a number of styles, such as pillow block styles, four-bolt flanged styles and the like. The housing includes a bearing set support surface and features for securing the housing to a machine frame. The reinforcing elements are edge-loaded to transmit loads on a bearing set to the support features and machine frame. Lateral faces of the reinforcing members contact the body material of the housing to prevent bending or buckling of the reinforcing members under loads.

Abstract: An apparatus for retaining a movable contact in a circuit interrupter includes a movable element that is displaced by gas pressure within the interrupter housing resulting from arcs generated during initial displacement of the movable element. The movable element may be a spanner extending between two stationary contacts. The apparatus may be configured as a three phase interrupter in which a single carrier or retainer is common to three power phase sections, and is displaced by interruption of a current carrying path for any one power phase section. The retainer may include a retaining pin which extends through the movable element. The movable element is biased into a conducting position and a head of the retaining pin contacts the movable element to hold it in a non-conducting position following a trip event.

Abstract: An auxiliary seal for a bearing includes a seal housing supported by the bearing housing, and a seal ring interference fitting around a mechanical element such as a shaft or sleeve supported for rotation by the bearing. The housing and sleeve include a series of rings that interface with one another to maintain the seal ring in place on the mechanical element. A face rubbing seal is supported on the seal ring and contacts a portion of the seal housing as the mechanical element rotates relative to the bearing housing. The seal ring has an integral backup portion which contacts the face rubbing seal to prevent the face rubbing seal from sliding axially away from the seal housing. A series of seal barriers are defined by the seal housing and seal ring, including contact seals, grease dams and labyrinth seals.

Abstract: A method and apparatus are provided for approximation of integral and RMS values for waveforms of uncertain or unknown period. The technique employed processes values of the waveform sampled at fixed sampling intervals, monitors the actual period of the waveform, and calculates the number of fixed sampling intervals in the period. The sampled data is then used as a basis for mapping the waveform onto a desired number of sampling points. Interpolation techniques are used to assign values to desired sampling points lying between fixed interval sampled points. The desired number of sample points is selected to permit use of Simpson's rule for approximating the integral value (an odd number of points for application of Simpson's 1/3 rule, and a number equal to a multiple of 3 plus 1 for application of Simpson's 3/8 rule). Once the desired sampling points are determined, Simpson's rule is applied to calculate the integral, and the RMS value may be determined based on this integral value.

Abstract: A fixture is provided for facilitating the fabrication of a motor controller of the type including a power substrate module and a control circuit board mounted to and electrically coupled to the power substrate module via a plurality of conductors. The fixture is preferably a ring-like structure made of epoxy-fiberglass laminate. Apertures for engaging and holding the conductors are provided in the fixture at locations corresponding to conducting pads on the power substrate module. For fabrication, the power substrate module and the fixture are preformed and solder is disposed on the conducting pads of the module. During fabrication, the conductors are inserted into the apertures in the fixture and the fixture and conductors are positioned over the preformed power substrate module to bring the conductors into contact with the conducting pads. The fixture and power substrate module are then passed through a reflow oven to melt the solder and complete the connection of the conductors to the module.

Abstract: A variable frequency motor drive incorporating a circuit interrupter includes a rectifying circuit for converting incoming AC power to DC power and an inverting circuit for converting the DC power to controlled AC power in response to control signals. A control circuit implements a preset control routine to control operation of the inverting circuit to drive a motor in accordance with desired operating parameters. A circuit interrupter is coupled between the source of AC power and the rectifying circuit and includes an actuator for interrupting power to the drive in response to interrupt command signals from the motor control circuit. The motor drive includes a switching circuit and a capacitive circuit for powering the circuit interrupter. The drive control circuitry monitors operation of the drive and the motor and when conditions require removal of power to the drive, the control circuitry commands the switching circuit to close, energizing the circuit interrupter and thereby removing power to the drive.

Abstract: A moisture drain plug for use with a cylindrical motor housing provides a plurality of diverse drainage pathways to promote the egress of moisture from within the housing. The plurality of diverse drainage pathways includes a first set of primary moisture egress pathways and a second set of secondary moisture egress pathways. Should one or more of the primary moisture egress pathways become clogged, the secondary moisture egress pathways provide for more than adequate drainage from the motor housing.

Abstract: A method and apparatus for controlling an AC motor are described wherein a frequency generator is configured to generate a signal representative of the stator electrical frequency and to estimate the rotor electrical frequency of the motor during operation. The generator operates on torque and flux current reference signals and on d-axis voltage reference and feedback signals to determine the electrical frequencies. The generator ramps up gain values applied to the torque current reference signals and to a voltage error signals representative of the difference between the d-axis voltage reference and feedback signals during a startup phase of operation to enhance performance and stability of the drive during this phase. The generator includes feedforward and feedback portions that contribute components of the final stator frequency signal. The components are filtered differently during startup and running phases of operation to provide the desired frequency signals.

Abstract: A fixture is provided for facilitating the fabrication of a motor controller of the type including a power substrate module and a control circuit board mounted to and electrically coupled to the power substrate module via a plurality of conductors. The fixture is preferably a ring-like structure made of epoxy-fiberglass laminate. Apertures for engaging and holding the conductors are provided in the fixture at locations corresponding to conducting pads on the power substrate module. For fabrication, the power substrate module and the fixture are preformed and solder is disposed on the conducting pads of the module. During fabrication, the conductors are inserted into the apertures in the fixture and the fixture and conductors are positioned over the preformed power substrate module to bring the conductors into contact with the conducting pads. The fixture and power substrate module are then passed through a reflow oven to melt the solder and complete the connection of the conductors to the module.

Abstract: A support and coupling arrangement for a proximity switch includes a support for mounting the switch enclosure in a desired orientation and permitting selective angular orientation of angled pin connectors coupled to the switch. The support includes a bore through which conductors to the switch circuitry pass and a first abutment surface. For interfacing the switch with pin connectors, a connector receptacle is provided in the bore. The receptacle includes a second abutment surface configured to cooperate with the first abutment surface to selectively prevent rotation of the receptacle in the bore. To select the angular orientation of the receptacle, and thereby of the connector, the receptacle is slid within the bore to disengage the abutment surfaces and the receptacle is rotated to the desired orientation. The receptacle is then slid axially to engage the abutment surfaces. Coupling the connector on the support secures or locks the receptacle and the connector in the selected orientation.