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Showing papers on "Rotor (electric) published in 1970"


Journal ArticleDOI
TL;DR: Rotor wakes intrastator transport effects on high Mach number axial flow compressors performance, considering stagnation temperature profile and rotor blade loss factor, were investigated in this article, where they showed that rotor wake intrastation transport effects had a significant impact on axial Flow Compressor performance.
Abstract: Rotor wakes intrastator transport effects on high Mach number axial flow compressors performance, considering stagnation temperature profile and rotor blade loss factor

193 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the rotors of a ducted rotor decays rapidly with distance away from the rotor, and this exponential decay, coupled with the low radiation efficiency of a subsonically rotating pressure pattern, is generally sufficient to bring the radiated sound power well below that produced by interaction of the rotor with disturbances in the flow.
Abstract: Over the subsonic speed range, the pressure field attached to a ducted rotor decays rapidly with distance away from the rotor. This exponential decay, coupled with the low radiation efficiency of a subsonically rotating pressure pattern, is generally sufficient to bring the radiated sound power well below that produced by interaction of the rotor with disturbances in the flow. This is particularly true for multibladed rotors as used in aircraft-engine fans and compressors, and accounts for the importance of rotor-stator interaction as a source of noise at subsonic tip speeds.

83 citations


Patent
30 Jul 1970
TL;DR: In this article, the rotor is a rotatably mounted circular disc including a plurality of electret portions disposed at equal angular intervals around the rotor disc, and the stator can comprise a pair of fixed discs, having opposing electrode portions.
Abstract: An electric motor comprises a rotor including a plurality of electret portions and a stator including an array of fixed electrode pairs for driving the electret rotor in response to an applied AC voltage. A significant advantage of this motor is the fact that it does not require either wound conductive coils or a laminated metal core; consequently, it can be more easily fabricated than typical prior art motors. In a preferred embodiment, the rotor comprises a rotatably mounted circular disc including a plurality of electret portions disposed at equal angular intervals around the rotor disc. The stator can comprise a pair of fixed discs, having a plurality of opposing electrode portions.

82 citations


Patent
03 Aug 1970
TL;DR: In this paper, a deformable insert is placed between two adjacent magnets and then deformed to enlarge the gap in which it is received, thereby compressing the spring member, and if the magnets are first formed into a preassembly with a shipping band for later assembly with a rotor part, the deformed insert is preferably deformed only to a degree sufficient to hold the preassembly in assembly with only a degree of tightness sufficient to withstand normal handling.
Abstract: The rotor of an electric alternator includes permanent magnet material for establishing a magnetic field which rotates with the rotor. The permanent magnet material may be in the form of a single ring of such material magnetically charged to provide a plurality of angularly spaced magnetic poles. The magnetic material may also be in the form of a plurality of separate magnets arranged in a generally end face to end face, spaced relationship to form an annular ring. The magnetic material is a ceramic material and the magnets directly provide pole faces for cooperation with the stator poles and are radially magnetically charged to include more than one magnetic pole on each pole face. When a plurality of magnets are used to form the magnet ring a compressible resilient spacer or spring member is placed between two magnets to hold them in assembly with a temporary shipping band or with the rotor part in which they are finally installed. In assembling a magnet ring made of a plurality of magnets, a deformable insert may be placed between two adjacent magnets and then deformed to enlarge the gap in which it is received, thereby compressing the spring member. If the magnets are first formed into a preassembly with a shipping band for later assembly with a rotor part, and if a deformable insert is used to control the compression of the spring member, the deformable insert in forming the preassembly is preferably deformed only to a degree sufficient to hold the preassembly in assembly with only a degree of tightness sufficient to withstand normal handling, and after the magnets are inserted in the final rotor part and the shipping band removed, the deformable insert is deformed to a further extent to hold the magnets in assembly with the rotor part with a greater degree of tightness.

64 citations


Journal ArticleDOI
TL;DR: In this paper, a number of methods for representing the losses in radial gas turbines for predicting the off-design performance are reviewed, and it is shown that reasonable predictions of the turbine performance may be made using one-dimensional theories if the nozzle gas exit angle is based on the cos−1(o/s) rule with some deviations due to rotor speed.

58 citations


Patent
Bernard L Koff1
01 Jun 1970
TL;DR: In this article, a system for cooling the rotor of an axial flow compressor incorporated in a gas turbine engine is described, where cooling air flows to the downstream end of the rotor and is then ducted back into the compressor inlet.
Abstract: The disclosure shows a system for cooling the rotor of an axial flow compressor incorporated in a gas turbine engine. Air is ducted from the first compressor stage discharge into the interior of the rotor. This cooling air flows to the downstream end of the rotor and is then ducted back into the compressor inlet.

56 citations


Journal ArticleDOI
TL;DR: In this article, a method for incorporating the rotor deep-bar effect in a dynamic simulation of induction machines under dynamic conditions has been presented, based on two-phase models using constant circuit parameters.
Abstract: Simulations of induction machines under dynamic conditions have heretofore been based on two-phase models using constant circuit parameters. Most induction motors in the integral horsepower sizes have rotor bars of sufficient depth that they cannot be accurately represented by a constant rotor resistance under all operating conditions A method for incorporating the rotor deep-bar effect in a dynamic simulation is presented.

55 citations



Patent
06 Nov 1970
TL;DR: Brushless reluctance motors are compatible with energization by the simple rectilinear voltages easily produced by motor control circuits having a small number of mechanical or solid state switches as mentioned in this paper.
Abstract: Brushless reluctance motors are compatible with energization by the simple rectilinear voltages easily produced by motor control circuits having a small number of mechanical or solid state switches. These motors with two or three opposing pairs of main and feedback stator windings, and suitable variable or constant gap nonpolarized rotors, require a like number of controlled switches and uncontrolled rectifiers actuated by a rotor position sensor to generate square wave voltages on which the reluctance motors operate efficiently.

51 citations



Patent
06 Nov 1970
TL;DR: Brushless motors have physical and electrical characteristics to be compatible with energization by the simple square or stepped wave voltages easily produced with inverter type motor control circuits having a small number of controlled switches responsive to a rotor position sensor as discussed by the authors.
Abstract: Brushless motors have physical and electrical characteristics to be compatible with energization by the simple square or stepped wave voltages easily produced with inverter type motor control circuits having a small number of controlled switches responsive to a rotor position sensor. These motors employ a few pairs of opposing non-distributed stator windings arranged overlapping or non-overlapping with a predetermined winding pitch, and a constant gap magnetically polarized or non-polarized rotor with pole faces having related angular dimensions, to thereby produce rectilinear back emf voltages with approximately the same wave shape as the energizing voltages. The circuits can control the applied voltage to adjust motor speed.

Patent
14 Sep 1970
TL;DR: In this paper, the stator and rotor windings of a turbo generator are cooled by rigid holding means secured in the open inner recess portions to the adjacent inner teeth portions, and cooling pipes for a coolant supported by the holding means are provided.
Abstract: A turbo generator has a rotor and a stator forming an annular gap. The inner surface of the stator has teeth and intermediate recesses whose outer bottom portions are taken up by stator windings. Cooling means are provided in the unused inner recess portions which are free of stator windings. The cooling means comprise rigid holding means secured in the open inner recess portions to the adjacent inner teeth portions, and cooling pipes for a coolant supported by the holding means so that the stator and rotor portions bounding the gap are efficiently cooled which is particularly advantageous when the rotor and stator windings are internally cooled.

Patent
03 Mar 1970
TL;DR: A thermoelectric cooling device is a cooling device that is interposed between two cylindrical rotors of the type similar to centrifugal fan rotors, with the vanes of the rotors hollowed and filled with a reflux heat transfer fluid.
Abstract: A thermoelectric cooling device. Thermoelectric modules are interposed between two cylindrical rotors of the type similar to centrifugal fan rotors, with the vanes of the rotors hollowed and filled with a reflux heat transfer fluid. The hollow vanes have fins attached to them. The thermoelectric modules are fed by a direct current source and cause one rotor to get cold and the by, rotor to get hot. The air which is flowing by, and near, each rotor becomes cool or warm, as the case may be. Shrouds around the rotors direct the air flows. The rotors and the thermoelectric modules are rotated, as one unit, by an electric motor.

Patent
09 Jul 1970
TL;DR: In this paper, an electromagnetic coupling is connected mechanically with an electric rotating machine having a stator, for instance a synchronous motor, a cage rotor type or wound rotor type induction motor etc.
Abstract: When an electromagnetic coupling is connected mechanically with an electric rotating machine having a stator, for instance a synchronous motor, a cage rotor type or wound rotor type induction motor etc., and the said electromagnetic coupling is connected electrically with the said electric rotating machine through a phase sequence change over switching device, further the electromagnetic coupling combined mechanically with the rotor of the electric rotating machine drives a load, and the other rotor of the electromagnetic coupling is driven by a driving machine, the electric machine arrangement has such advantages as shown by (1) obtaining power transmitting devices with operation similar to reduction gears which transmit outputs of other driving machines to loads; (2) possibility of driving one rotor of electromagnetic coupling in direction opposite to the rotation of the other rotor; and so forth. If the mechanical combination between the rotor of the electromagnetic coupling and the rotor of the electric rotating machine is made by using a rotor in common for the electromagnetic coupling and for the electric rotating machine, the electric machine arrangement becomes compact.

Patent
Tritus F Watson1
06 Apr 1970
TL;DR: In this paper, the stator windings of a brushless DC motor are energized through individual silicon controlled rectifiers arranged in a ring counter circuit which is triggered from a pulse source.
Abstract: The stator windings of a brushless DC motor are energized through individual silicon controlled rectifiers arranged in a ring counter circuit which is triggered from a pulse source. When the motor is to be started, an AND gate forces the first pulse to trigger a specific silicon controlled rectifier. The AND gate then permits subsequent pulses to be steered to various silicon controlled rectifiers in the desired sequence. The pulse source is synchronized through an OR gate coupled to receive signals from each stator winding. When a given silicon controlled rectifier is turned off, the corresponding stator winding is deenergized. The motion of the rotor, however, induces a counter EMF in the deenergized winding. This counter EMF is applied through the OR gate to synchronize the pulse source.

Patent
22 Jun 1970
TL;DR: In this paper, the stator members are formed of mild low-carbon steel that is annealed after fabrication, and the rotor is a permanent magnet ring with as many poles as the stators, mounted in a single unitary bearing structure.
Abstract: A small permanent magnet synchronous motor having one or more pairs of stator sections mounted in tandem. Each stator section includes a first annular stator member of generally U-shaped cross section with multiple pole pieces around the inside of the annulus parallel to the axis, the pole pieces preferably being of tapered construction. A similar second annular stator member interfits with the first stator member; the pole pieces of the second stator member are interleaved one-for-one with the pole pieces of the first stator member. The stator members are formed of mild low-carbon steel that is annealed after fabrication. In each stator section, a coil encompasses the pole pieces of the stator members. The rotor is a permanent magnet ring with as many poles as the stator sections, mounted in a single-unitary bearing structure. The motor is assembled by coating one inner frame member with an epoxy resin adhesive, assembling the inner frame members back-to-back on a gauge hub with interengaging index elements assuring accurate alignment at a displacement of 90* electrically between the stator sections, then adding the coils and outer stator members.

Journal ArticleDOI
TL;DR: In this article, the influence of flexible antennas and solar panels on the dynamic behavior and control system response of a two-body spacecraft, one part of which may spin, is investigated.
Abstract: The influence of flexible antennas and solar panels on the dynamic behavior and control system response of a two-body spacecraft, one part of which may spin, is investigated. Space vehicles are modeled with a rigid platform to which are attached a rigid rotor, a damped linear oscillator (simulating a "nutation damper"), and one or more flexible appendages. Flexibility is accommodated by use of modal deformation coordinates for the appendages in combination with discrete coordinates of the platform, rotor and damper. The presence of a damper on a nonrotating platform would in the absence of flexibility and active control maintain the rotor spin axis in coincidence with the angular momentum vector. A third despin control system is designed to maintain attitude control of the platform about the bearing axis. Attitude control jets provide angular momentum control on command. Linearized equations provide the basis for digital simulation and for stability determination by eigenvalue analysis, permitting the assessment of the influence of flexible appendages on vehicle behavior.

Patent
15 Sep 1970
TL;DR: In this article, the rotor bars of a high starting torque squirrel cage motor are insulated from the sheet metal laminations forming the rotor by disposing insulating Laminations at spaced apart locations along the rotor axis.
Abstract: Rotor bars of a high starting torque squirrel cage motor are insulated from the sheet metal laminations forming the rotor by disposing insulating laminations at spaced apart locations along the rotor axis. The insulating laminations are pre-slit in registration with the slots of the juxtaposed sheet metal laminations and as the rotor bars are driven through the sheet metal laminations, the leaves of the pre-slit insulating laminations are folded back by the advancing bars to electrically insulate the rotor bars from the sheet metal laminations.

Patent
Werner Kruse1
08 Dec 1970
TL;DR: In this paper, a measurement sensing device for detecting a rotational speed change of vehicle wheels is presented. But the rotor and stator are not combined into a structural unit, and the rotor is not rotated relative to the stator at the latter or at a part connected therewith.
Abstract: A measurement sensing device for detecting a rotational speed or rotational speed change, particularly of vehicle wheels, which essentially consists of a rotor and of a stator constructed as magnet and equipped with an annular coil, whereby an A.C. voltage proportional to the rotational speed is induced in the stator by the rotation of the rotor; the rotor and stator are thereby so combined into a structural unit that the rotor is so rotatably supported relative to the stator at the latter or at a part connected therewith that during operation no changes in radial or axial spacing between rotor and stator occur.

Patent
14 Dec 1970
TL;DR: In this paper, the rotor drive shafts comprise telescoping shaft portions for shifting the rotors between an extended operating position overhead the aircraft fuselage and a retracted stowed position received within longitudinally extending pockets in the fuselage.
Abstract: A STOL aircraft having a fixed wing and a rotor blade mechanism with a rotor support mounted on the aircraft fuselage for pivotal movement about a laterally extending axis, a pair of laterally spaced upwardly extending and laterally outwardly inclined rotor drive shafts mounted on the pivotal rotor support, and single bladed rotors mounted on the drive shafts for rotation in opposite angular directions in noninterfering synchronism. The rotor drive shafts comprise telescoping shaft portions for shifting the rotors between an extended operating position overhead the aircraft fuselage and a retracted stowed position received within longitudinally extending pockets in the fuselage.

Patent
09 Apr 1970
TL;DR: A cylindrical rotor having a continuous spiral cam slot formed in its periphery reciprocates a breech block to drive rounds of ammunition into a barrel, to fire the round and to extract the expended cartridges after firing as discussed by the authors.
Abstract: A cylindrical rotor having a continuous spiral cam slot formed in its periphery reciprocates a breech block to drive rounds of ammunition into a barrel, to fire the round and to extract the expended cartridges after firing. A cam on the front end of the rotor controls movement of a lock which temporarily locks the breech block during the firing operation. Ejector pins on the rotor thrust an ejected cartridge sideways as the breech block is being reciprocated rearwardly. A cam on the rear of the rotor controls the feeding ammunition into the path of the breech block.

Patent
14 Dec 1970
TL;DR: In this article, a turbine engine having a gasifier turbine rotor and a power turbine rotor, a bearing frame providing a bearing support for the shaft of the turbine, the bearing frame and a turbine nozzle being integrally formed to provide a continuous annular passage between the rotors.
Abstract: A turbine engine having a gasifier turbine rotor and a power turbine rotor, a bearing frame providing a bearing support for the shaft of the gasifier turbine rotor, the bearing frame and a turbine nozzle being integrally formed to provide a continuous annular passage between the rotors, support struts extending radially across the annular passage within the bearing frame being integrally formed with respective vanes extending radially across the annular passage within the turbine nozzle to simplify construction of the turbine engine and reduce flow disturbance within the annular passage.

Patent
22 Jun 1970
TL;DR: In this article, the lower end of the CASing of the VERTICALLY MOUNTed Hermetic COMPRESSOR UNIT is formed with an OIL SUMP to which the LIQUID OIL-this articleRIGERANT MIXTURE is ELEVATED from the SUMP by a LIFT TUBE FIXED to and depending from the MOTOR ROTOR.
Abstract: THE LOWER END OF THE CASING OF THE VERTICALLY MOUNTED HERMETIC COMPRESSOR UNIT IS FORMED WITH AN OIL SUMP TO WHICH LIQUID REFRIGERANT IS SUPPLIED THE LIQUID OIL-REFRIGERANT MIXTURE IS ELEVATED FROM THE SUMP BY A LIFT TUBE FIXED TO AND DEPENDING FROM THE MOTOR ROTOR DURING OPERATION OF THE MOTOR, A ROTATIONAL VORTEX IS FORMED IN THE TUBE AND THE LIQUID MIXTURE IS PASSED UPWARDLY THROUGH AXIALLY EXTENDING PASSAGES IN THE ROTOR AND IS DISPENSED ON THE UPPER AND LOWER END TURNS OF THE STATOR WINDINGS SUCTION IS APPLIED TO THE CASING ABOVE THE MOTOR FOR REMOVAL OF REFRIGERANT VAPOR

Patent
31 Mar 1970
TL;DR: In an axial piston hydraulic device, the cylinders in the rotor communicate with the high and low pressure ports of the device by way of passages which are positioned between the axes of the cylinders and the rotational axis of the rotor to reduce resistances to fluid flow resulting from rotor rotation when the cylinders are on their low pressure stroke as mentioned in this paper.
Abstract: In an axial piston hydraulic device, having an angularly tiltable tilt plate for controlling the stroke of the pistons, the cylinders in the rotor communicate with the high and low pressure ports of the device by way of passages which are positioned between the axes of the cylinders and the rotational axis of the rotor to reduce resistances to fluid flow resulting from rotor rotation when the cylinders are on their low pressure stroke. Additional passages are provided which communicate the high pressure port with the rotor and/or the bearing of the tilt plate to exert counterbalancing forces on these components during operation of the device. On- and off-stroke control pistons may also be positioned on the side of the tilt plate opposite the pistons to exert counterbalancing forces on the tilt plate.

Patent
Andrew F Deming1
03 Jun 1970
TL;DR: In this paper, a two-pole offset construction of an electric motor has winding portion laminations and rotor portion lamination which are separate so that the winding may be formed or placed on the winding portion and then the two portions of the stator interconnected to complete the rotor circumscribed by a rotor aperture in the rotor portion.
Abstract: A two-pole off-set construction of an electric motor has winding portion laminations and rotor portion laminations which are separate so that the winding may be formed or placed on the winding portion and then the two portions of the stator interconnected to complete the flux path for the rotor circumscribed by a rotor aperture in the rotor portion. There must be a window space between these two portions to accommodate the winding on the winding portion and formerly the metal removed from this window space was scrap metal, necessitating an excessive amount of steel lamination material. In this invention, the layer of lamination is made in two complementary pieces and this layer has a rotor portion and a winding portion. The two separate lamination pieces for a layer of complete lamination are to permit the winding to be placed on this complete stator. The material removed from the window space instead of being scrap is utilized as an active flux carrying member by being unitary with one of these first and second lamination pieces. In a first embodiment of the invention the legs joining the end areas of the winding and rotor portions are off-set in the direction toward the winding portion by approximately one-eighth of their length resulting in the bight of the rotor portion, which contains the rotor aperture, being displaced in a direction opposite to the leg extensions. Accordingly, laminations for only the rotor portion are successively formed from a strip of lamination material with the bight of the rotor portion extending into the space between the two legs of the next adjacent rotor portion lamination in the strip of lamination material. In a second embodiment of the invention the rotor and winding portions are unitary on a first piece of the lamination and complementary with a small second piece of lamination. The first pieces of the lamination are nested or interlocked together as they are formed from the lamination steel, utilizing the window space of one piece as the winding portion of the adjacent first lamination piece. This utilizes lamination material from the window space which would otherwise be scrap and saves approximately one-eighth of the steel used in making the motor. The winding portion or second piece laminations are separately made adjacent to each other in a strip of lamination material. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

Patent
06 Jul 1970
TL;DR: In this article, a cooling arrangement for a squirrel cage rotor assembly of an alternating current electric drive motor includes a pair of rotor end plates clamped to the ends of a rotor core carrying conductive end rings extending from the end of the rotor core.
Abstract: In a preferred form, a cooling arrangement for a squirrel cage rotor assembly of an alternating current electric drive motor includes a pair of rotor end plates clamped to the ends of a rotor core carrying a pair of conductive end rings extending from the ends of the rotor core. The rotor end plates form end ring cooling cavities circumscribing the inner peripheries of the end rings. The rotor core is carried by the motor shaft and a recessed area on the outer diameter of the shaft forms axial cooling channels in heat conducting relation with the inner bore of the rotor core. A pair of concentric axial shaft passages extend through a bore in the center of the shaft and communicate with radial shaft passages connected with the end ring cooling cavities and with the axial cooling channels. A hollow insert is mounted in the shaft bore for separating the pair of axial shaft passages. A liquid coolant is circulated from one end of the shaft through the end ring cooling cavities and the annular cooling chamber to transfer heat from the end ring and the rotor core.

Patent
13 Mar 1970
TL;DR: In this paper, an elastomeric rotor mounting structure for a helicopter blade is provided, where a blade grip is coupled to a yoke structure by means of radial-thrust elastomers and the yoke is connected to the rotor hub.
Abstract: An elastomeric rotor mounting structure for a helicopter blade is provided. In the mounting, a blade grip is coupled to a yoke structure by means of radial-thrust elastomeric bearings and the yoke structure is connected to the rotor hub. The elastomeric bearings simplify the rotor design and eliminate the need for bearing lubrication.

Journal ArticleDOI
01 Mar 1970
TL;DR: The principles and design method of a new type of reluctance motor are described, which combines the advantage of simplicity of manufacture with a performance which is satisfactory by any present standard.
Abstract: The principles and design method of a new type of reluctance motor are described. The rotor of the new machine has one system of flux barriers per pole pair and is nonsegmented. The machine combines the advantage of simplicity of manufacture with a performance which is satisfactory by any present standard.

Patent
08 May 1970
TL;DR: In this article, the authors proposed a method for providing a sequence of stopping pulses derived from motor feedback pulses, which can be used to bring a stepping motor to its equilibrium position.
Abstract: The invention is concerned with circuitry for providing a sequence of stopping pulses derived from motor feedback pulses. It includes means for providing an initial stop pulse which reverses the phase of the motor to thereby develop a negative torque. Intermediate stopping pulses in the form of feedback pulses continue to apply the negative torque to the rotor. A final stopping pulse not derived from the feedback pulses is applied to bring the motor to its equilibrium position. In this manner, a stepping motor can be stopped with substantially no oscillations after a specified number of steps.

Patent
24 Aug 1970
TL;DR: In this paper, a propulsion mechanism for propelling liquids first radially and then axially through the mechanism at high pressure, the mechanism having within a cylindrical housing a rotor balanced to minimize radial and axial forces on the rotor whereby bearings are not required for the rotor.
Abstract: A propulsion mechanism, such as a pump, for propelling liquids first radially and then axially through the mechanism at high pressure, the mechanism having within a cylindrical housing a rotor balanced to minimize radial and axial forces on the rotor whereby bearings are not required for the rotor.