Abstract: An electric machine includes a rotor, a stator disposed about the rotor and including a plurality of poles with electromagnetic coils, an electric power source electrically connected with the stator coils, a commutating circuit electrically connecting the power source with the coils and a controller. The controller operates the commutating circuit in an energization sequence such that current flows alternatively through the first and second phases of the electromagnetic coils, the controller repeating the energization sequence at an energization frequency proportional to the rotation frequency. However, the controller modifies the energization sequence such that current flow is prevented or reduced through at least one of the first and second phases of the electromagnetic coils when the controller determines that rotation speed of the rotor is approaching a value at which energization frequency creates resonance within the rotor.

Abstract: A system for processing a product includes a tool that processes the product and a rotor assembly including a rotor supporting the product and a stator with actuator(s) exerting torque on the rotor. A tool controller operates the tool and transmits speed request signals including a desired speed of the rotor and a control pulse having a threshold value repeating at the expiration of a period proportional to a desired rotation period of the rotor at the desired speed. A rotor controller receives both the speed request signal and the control pulse, controls the stator actuator(s) such that the rotor rotates at the desired speed and phase, and transmits a rotor position pulse and/or phase information to the tool controller once every predetermined angular displacement of the rotor. The tool controller operates the tool based on the angular position of the rotor as calculated using information from the rotor controller.

Abstract: A device for conditioning a measurement signal supplied by an inductive position sensor (7, 8) for a rotor (3) of an electric machine (1) supported by at least one active magnetic bearing (4). The inductive position sensor (7, 8) measures a displacement of the rotor (3) and is supplied by an alternating voltage source (10a) supplying a sinusoidal voltage at a predetermined constant frequency. The device includes a sampler (15) and a first means (16). The sampler (15) samples first and second samples of the measurement signal at different times. The first means breaks down the measurement signal into a sum of a sine function and a cosine function from the first and second samples of the measurement signal.

Abstract: A magnetic bearing assembly having a signal conditioning circuit that includes an offset generator for adding a digitally controllable analog offset to compensate for displacement error in unbalanced inductive sensors.

Abstract: A magnetic bearing assembly having a signal conditioning circuit that includes an offset generator for adding a digitally controllable analog offset to compensate for displacement error in unbalanced inductive sensors.

Abstract: A system and method for analyzing a scenario, such as a communications scenario in which the end-to-end quality of communications between end nodes of a communications link may be affected by various factors and conditions. Such factors and conditions may include performance parameters of the end nodes and intermediate nodes, human operational performance, and external conditions, such as weather. Qualitative and quantitative representations of the end-to-end quality of communications are presented simultaneously and in a time-synchronized manner with displays of the relevant performance parameters, indications of human operational actions, and locations of nodes of the communications link and external conditions.

Abstract: A system and method for analyzing a scenario, such as a communications scenario in which the end-to-end quality of communications between end nodes of a communications link may be affected by various factors and conditions. Such factors and conditions may include performance parameters of the end nodes and intermediate nodes, human operational performance, and external conditions, such as weather. Qualitative and quantitative representations of the end-to-end quality of communications are presented simultaneously and in a time-synchronized manner with displays of the relevant performance parameters, indications of human operational actions, and locations of nodes of the communications link and external conditions.

Abstract: A system and method for analyzing a scenario, such as a communications scenario in which the end-to-end quality of communications between end nodes of a communications link may be affected by various factors and conditions. Such factors and conditions may include performance parameters of the end nodes and intermediate nodes, human operational performance, and external conditions, such as weather. Qualitative and quantitative representations of the end-to-end quality of communications are presented simultaneously and in a time-synchronized manner with displays of the relevant performance parameters, indications of human operational actions, and locations of nodes of the communications link and external conditions.

Abstract: An angular position detector includes a cylindrical rotor having an axis of rotation and a first ring with a plurality of alternating teeth and valleys, a first first-ring magnetic sensor having a sensor surface facing the first ring, the first first-ring magnetic sensor being configured to produce a first signal in response to movement of the first ring past the first first-ring magnetic sensor, a second first-ring magnetic sensor having a sensor surface facing the first ring and being configured to produce a second signal in response to movement of the first ring past the second first-ring magnetic sensor, the second first-ring magnetic sensor being circumferentially offset from the first first-ring magnetic sensor by a first angle and a controller operatively connected to the first and second first-ring magnetic sensors and configured to produce a first output signal based on the first and second signals.

Abstract: A self-propelled, mobile articulated tramming haulage conveyor system includes a continuous series of individual cascading mined material haulage conveyors located over one or more long continuous chain, conveyor system tramming apparatus or flexible crawlers. For negotiation of corners or bends in a borehole, the frame on which the continuous chain, conveyor system tramming system is mounted is flexible.

Abstract: A split sprocket and retainer assembly are provided for mounting on the drive shaft of a chain drive system, such as a conveyor drive system. The sprocket is split diametrically into two sections and includes a hub. Cross fixing bolts across the hub secure the two sprocket sections together on the drive shaft. A one-piece retaining ring is positioned over the sprocket hub in snug engagement, and overlying the bolts. The retaining ring absorbs the thrust force generated by the driving torque tending to radially separate the sprocket sections during operation of the drive system. A split outer retainer collar is mounted so as to abut the retaining ring and to secure it in position against axial shifting and backing off the hub.