Abstract:
A support and positioning structure for a stator assembly (4) of an inductor type dynamoelectric machine (2) is disclosed. The stator assembly (4) includes a plurality of stationary C-shaped armature elements (26) circumferentially located about a central longitudinal axis (6) and supported by end portions (14). The C-shaped armature elements (26) include armature windings (24) on a base portion extending parallel to the longitudinal axis (6) and legs (34) extending from each end in a radially inward direction. The support structure includes a nonmagnetic ring shaped member (9) sized to be insertable over the bases of the circumferentially spaced C-shaped armature elements (26). The bases are in contact with an inner portion (29) of the ring shaped member (9) to thereby position the C-shaped armature elements (26).
Abstract:
A wind-turbine gearbox system includes an input gear stage having mating gear surfaces finished to a surface roughness of less than 0.25 micron and at least one bearing supporting the input gear stage. A lubrication circuit is arranged to deliver lubricant to the input gear stage and the bearing during operation of the wind-turbine and includes an inline filter for removal of particles of less than 2 micron from the lubricant prior to delivery. A lubricant for use in the system may have a relatively low viscosity compared to conventional wind turbine gearbox lubricants.
Abstract:
A fixture is provided for retaining a metal workpiece for contact by finishing media during operation of a media based finishing operation. The fixture comprises a body and a magnet for retaining the workpiece in contact with the body. By use of super-magnetic materials a significant holding force may be achieved.
Abstract:
A method for superfinishing a high density carbide steel component using chemically accelerated finishing is provided. The high density carbide steel component is vibrated in a vessel containing a plurality of media, with active chemistry being added to the vessel at a low flow rate. An active chemistry composition is also provided, consisting of one or more conversion coating agents having preferably a phosphate radical, and one or more chelating agents preferably including citric acid.
Abstract:
A rotor (14) for a dynamoelectric machine (10), without windings and rotatable about a central longitudinal axis (18), having an axially extending rotatable body and a toroidal magnet (58) coaxially mounted on the body is constructed to provide magnetic excitation for the rotor (14). The rotatable body contains a first set of circumferentially spaced axially extending salient poles (28) with circumferentially spaced recesses (26) therebetween and a second set of similar poles (28) at an opposite axial location. The toroidal magnet (58) is coaxially mounted on the body between the first and second set of salient poles (28). A second toroidal magnet (158) may also be mounted on the body and a magnetic spacer (161) placed in between both toroidal magnets (58, 158).
Abstract:
A system for supporting conductors (30) in a dynamoelectric machine (2) having a stator assembly (4) with a plurality of stationary armature elements (26) spaced about a circumference positioned radially about a central longitudinal axis (6), where each armature element (28) includes an armature winding (24) on a base portion and a leg extending from each of the base portions in a radially inward direction, includes a spacer (60) for supporting one or more electrical conductors (30) and for insulating the one or more conductors (30) for an armature element (26). The spacer (60) is mountable on the armature element (26) and may comprise one or more grooves (62) for supporting one or more interconnecting bars (30) which are capable of connecting the armature windings (24) of two or more armature elements (26). The spacers (60) may be fastened to the stator assembly (4) and allow the stator assembly (4) to be equipped with conductors (30) which may be oriented in a pattern which minimizes conductor length and minimizes energy losses.
Abstract:
Methods of operating a digital computer to optimize project scheduling. Where the overall effects of a schedule, such as total project duration or cost, are unsatisfactory, the schedule is processed iteratively so that on each iteration a particular task is selected for modification according to a preset policy (52) and data defining an aspect of that task is adjusted in a small step (72). A schedule is further optimized to fit the available resources by a repetitive process of assigning resources having the proper capabilities to tasks (102) according to a predetermined order of tasks and testing whether the assigned resource can permit shortening of the task duration (116). Further methods select an optimum mix of capabilities to be provided by each of several resources (222) to be hired for a project.
Abstract:
A snubber network (32) for a power conversion circuit (30) operated in discontinuous conduction mode includes a snubber capacitor (C), an isolation diode (D2) and an active reset circuit (S2, L, D3). The snubber capacitor (C) connected to the output of the isolation diode (D2), are connected across a main switch (S1) of the power conversion circuit (30). The active reset circuit (S2, L, D3), connected between the input and output of the isolation diode (D2) and the input and output of a boost diode (D1), is responsive to a reset signal for resetting the snubber capacitor within the normal boost cycle of the power conversion circuit (30). Upon receipt of the reset signal, energy in the snubber capacitor (C) is recovered and transferred to the output of the power conversion circuit (30) with turn-off of the main switch (S1). Soft switching is provided for both the main switch (S1) and a snubber switch (S2) within the active reset circuit (S2, L, D3).
Abstract:
The presence, size and location of a crack in a shaft (42) is determined by comparing actual measured natural frequencies of the operating shaft system with the results of an analytical model (62). From a multi-station analytical model (62) of an uncracked operating shaft system, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack (C) is defined, and a natural frequency of interest is selected which has an associated mode shape exhibiting significant localized bending at the suspected axial location of the crack (C) and at a site of response measurement (R). The analytical model (62) is modified to include an asymmetric crack. A comparison of actual natural frequency(s) in the region near the natural frequency of interest with frequency values predicted by the modified model is employed to determine the presence and severity of a crack in the shaft (42).
Abstract:
A spool-like stator support structure for an inductor type dynamoelectric machine incorporates stamped, annular end plates. Each end plate has a plurality of spaced-apart recessed landings along its outer edge and, preferably, a plurality of axially outward extending tabs which cooperate to precisely position a plurality of circumferentially distributed generally U-shaped armature elements mounted thereon. The end plate is also provided with a rabbet or press fit along its radially inner edge for mating with an end of the central cylindrical tube of the spool-like support. Cooling ports also distributed about the inner edge of the laminated end plate provide for ventilation of the exterior of said central tube. The end plate can be assembled from a grouping of standardized stampings or from a single stamping.