Showing papers on "Rotor (electric) published in 1976"

Aerodynamic performance of wind turbines

Abstract: This report summarizes the state-of-the-art of performance prediction methods for both horizontal and vertical axis wind turbines. Strip theory methods for horizontal axis wind turbines are evaluated for various tip loss models and occurrence of multiple solutions in strip theory analysis is discussed and illustrated. The performance of high-solidity turbines such as the Chalk design also are discussed. The configuration and performance of optimum horizontal axis wind turbines are addressed. Optimization schemes are developed and discussed and comparisons with the MOD-O rotor are made. Performance at off-design conditions is also examined. Performance prediction methods for vertical axis wind turbines are covered. The performance model for the Darrieus Rotor is developed. Multiple solutions are found to occur for Darrieus Rotors in the same manner as occurs for horizontal axis rotors. This flow model is compared to existing experimental data and shown to yield excellent agreement. An analytical model of the flow in a Savonius Rotor is presented. The flow model is shown to predict the essential features of flow in Savonius Rotors with consideration of viscous effects. (GRA)

Method of manufacturing a curved component of a magnetic circuit

Abstract: Identical strips of magnetic metal having alternating slots and pole teethlong one edge are cut from sheet material in a pattern minimizing waste of metal, stacked, and bent into a cylinder or sector of a cylinder. The ends of the stacks are then fastened together to form a rotor or stator.

Flow system for centrifugal liquid processing apparatus

Abstract: A seal-less disposable flow system for use in conjunction with a centrifugal liquid processing apparatus or the like wherein a rotor assembly for subjecting a liquid to be processed to centrifugation is rotatably mounted on a rotor drive assembly, which is rotatably mounted to a stationary base. The rotor assembly is rotatably driven in the same direction as the rotor drive assembly with a speed ratio of 2:1. The flow system includes two containers adapted for mounting on the rotor assembly and a flexible umbilical cable which extends from the containers to a location external to the apparatus by way of a passageway provided in the support shaft of the rotor assembly and guide means carried on and rotatably mounted to the rotor drive assembly to maintain liquid communication with the containers during rotation of the rotor without the use of rotating seals. A reusable leader assembly facilitates installation of the flow system in the processing apparatus.

Centrifugal liquid processing apparatus

Abstract: A centrifugal cell processing apparatus wherein a rotor assembly having a pair of containers for receiving a fluid to be processed by centrifugation is rotatably mounted on a rotor drive assembly, which is rotatably mounted on a stationary base. Liquid communication is maintained with the containers during rotation of the rotor by means of a flexible umbilical cable which extends from the containers to a location external to the apparatus by way of a passageway provided in the support shaft of the rotor assembly and a guide sleeve carried on and rotatably mounted to the rotor drive assembly. The rotor assembly is rotatably driven in the same direction as the rotor drive assembly with a speed ratio of 2:1 to prevent the umbilical cable from becoming completely twisted during operation of the apparatus. A guide sleeve may be provided on the rotor drive assembly to assist in installing the umbilical cable and to support the cable during operation.

Energy storage apparatus

Abstract: An energy storage device comprises a flywheel rotor in the form of a spokeless ring of filamentary, composite material rotating around a ring-shaped stator. Along the inner rim of the rotor, there is a layer of magnetically soft iron that forms homopolar, salient pole pairs. An ironless armature winding mounted on the stator extends into an air gap formed between the pole pairs. To bring the rotor up to speed, alternating current is supplied to the armature winding using electronic commutation. The armature current interacts with flux in the air gap to create a force acting to rotate the rotor. During coast down, current may be tapped from the rotor using commutation diodes. The rotor and stator are maintained in axial alignment to each other by magnetic flux produced by a permanent magnet in the stator. An electromagnet incorporated in the stator modulates permanent magnet flux to compensate for any eccentricity between the stator and the rotor that may develop during rotation.

Magnetically driven centrifugal pump

Abstract: A magnetically driven centrifugal pump comprises a split plate for dividing a space within a housing into two parts-impeller chamber and rotor chamber, a shaft supported by an inner wall of said rotor chamber and the split plate and having an internal rotor, an external rotor disposed outside the housing to magnetically drive the internal rotor, a passage means for permitting the communication between the impeller chamber and rotor chamber, and a restricting means for reducing the pressure of a fluid passing through said passage means.

Means for stabilizing an a-c electric motor drive system

Abstract: For use with an adjustable speed a-c electric motor having a stator adapted to be coupled to a source of variable frequency excitation and a rotor in which torque is developed when the motor is excited, the strength of said torque being dependent on interacting current and flux in the motor, a scheme is provided that comprises means for deriving an angle feedback signal representative of the actual phase angle between the aforesaid current and flux and means responsive to said angle feedback signal for controlling the source of variable frequency excitation so as to control the frequency of stator excitation as a function of the angle feedback signal.

Paired blade assembly

Abstract: A rotor blade system which is adaptd for long term reliable operation in a gas turbine engine is disclosed. Techniques incorporating composite materials into the rotor system are developed. One rotor structure shown utilizes a paired blade assembly having a core of continuous fibers running from the tip of one blade to the tip of the adjacent blade. Each of said paired blade assemblies is mchanically detachable from the engine rotor.

Aerodynamic performance of wind turbines. Final report

Abstract: The state-of-the-art of performance prediction methods for both horizontal and vertical axis wind turbines is presented. Strip theory methods for horizontal axis wind turbines are evaluated for various tip loss models. A comparison of these tip models is developed for the ERDA-NASA MOD-O rotor. The occurrence of multiple solutions in strip theory analysis is discussed and illustrated. The performance of high-solidity turbines such as the Chalk design is also presented. Corrections to the strip analysis techniques are developed and incorporated into the analysis used for conventional horizontal axis wind turbines. The predicted performance of the Chalk Turbines is presented. The configuration and performance of optimum horizontal axis wind turbines are discussed. Optimization schemes are developed and discussed and comparisons with the MOD-O rotor are made. Performance at off-design conditions is also examined. The performance model for the Darrieus Rotor is developed. Both linear and non-linear theories are developed. Multiple solutions are found to occur for Darrieus Rotors in the same manner as occurs for horizontal axis rotors. This flow model is compared to existing experimental data and shown to yield excellent agreement. An analytical model of the flow in a Savonius Rotor is presented.

Bearing and drive structure for spinning turbine

Abstract: A bearing and drive structure for the funnel-shaped spinning element of an open-end spinning turbine, composed of a stator with a projecting portion carrying an elastically mounted bearing and a rotor with a cup-shaped portion into which the projecting portion of the stator extends, the rotor being carried by the bearing and having its center of gravity at least approximately in the region defined between the axial ends of the flexible bearing, the stator carrying electrical windings cooperating with the cup-shaped rotor portion to form an electrical drive for the rotor

Radial magnetic bearing

Abstract: Iron rings and radially polarized magnets are alternated with axially magnetized rings on both a rotor and a stator in which like poles of axial magnets on and between the rotor and stator face one another to produce a field within the air gap between the magnets equivalent to that produced by radially magnetized magnets, to redistribute flux within the air gap, to smooth out non-uniformity of individual magnetic flux distributions, to provide repulsion between the stator and the rotor, to minimize energy losses due to rotor rotation, to produce a uniform field in the air gap despite non-uniformity in the magnets, to reduce spin drag torques due to non-uniform magnetization to near zero value, to maximize the flux collection effectiveness of the iron rings, to fill the entire volume with a useful material, and to obtain a more intense field in the air gap, thereby providing a weight effective structure.

Interblade damper and seal for turbomachinery rotor

Abstract: An interblade seal and vibration damper to be positioned in the damper cavity defined between a rotor disc, adjacent blades and adjacent blade platforms so as to seal across an interplatform gap by providing line contact between the damper and the platforms on opposite sides thereof for the full axial dimension of the cavity and with the damper shaped so as to have a low center of gravity for operational stability and which damper also responds to centrifugal force during rotor operation to establish damping friction between said damper and said platforms when the platforms move circumferentially.

Progressive cavity drive train

Abstract: An improved drive train for a progressive cavity device is disclosed. The progressive cavity device has a rotor, a stator, means for fluid to enter between said stator and rotor, and means for fluid to exit therefrom. The rotor is adapted to roll with respect to the stator. The improved drive train comprises means attached to the rotor, for rotation substantially about a single axis, whereby the rolling of said rotor and the rotational motion about said single axis are directly connected and are at different speeds. At least a portion of said means attached to the rotor is aligned with the true center of the rotor.

Rotary device driven by a moving fluid

Abstract: A rotary device driven by a moving fluid, such as water or air, for generating a rotary movement comprises a cylindrical or frusto-conical rotor having a vertical axis, the rotor having a plurality of identical blades distributed around the periphery of the rotor, each blade having a symmetrical aerodynamic profile and being mounted so as to freely rotate about a substantially vertical axis parallel to its leading edge. The device may be used to power a screw driven boat, a wheeled vehicle or other machinery.

Francis-type hydraulic machine

Abstract: The disclosure concerns a Francis-type hydraulic machine, i.e., a turbine, pump-turbine or pump, having a bladed wheel of large diameter, and in which bearing apparatus for supporting the rotor is arranged in a peripheral region of the bladed wheel spaced radially from the axis.

Motor driven pump

Abstract: A motor driven pump is described having an improved and simplified construction of pump casing and impeller with easy adaptability of the components over a wide range of capacity, an improved construction of the motor stator and rotor with structure which is adaptable for selection for use over a wide range of input, improved structure for alignment and support of the motor stator and of the motor rotor from a reference element referred to as a post, and without compounding and piling up of tolerances, and with adequate provisions for cooling and for pressure balancing.

Wind driven electrical generator

Abstract: An electric generating system in which oppositely rotating wind driven wheels are used, one to drive the rotor and one to drive the stator of an electric generator.

Caliper brake with assembly for rotor attachment to hub

Abstract: A rotor for a caliper brake and rotor therefor is provided with apposed chamfers adapted to seat over a flange on a wheel hub and the rotor is attached to the flange with the flange seated in one or the other of the chamfers. Thus, when the rotor is attached in one position, it is closer to the hub than when it is attached in the other position. A single rotor therefore is adapted to fit a plurality of different caliper brakes.

Matching thermal expansion of components of turbo-machines

Abstract: A turbo-machine casing comprises a part double skinned portion at a location surrounding at least one stage of rotor blades; the spaces defined between the two skins containing a heat insulating medium, and the inner of the two skins being additionally provided upon its radially innermost surface with a lining of heat insulating material, the casing being connected to a mass disposed radially outwardly of the casing whereby the rate of thermal expansion of the casing can be reduced nearly equal to the bladed rotor which it surrounds.

Variable-speed regenerative brushless electric motor and controller system

Abstract: A synchronous polyphase motor is driven and regeneratively braked by relatively high-frequency power switching circuits that cause stator currents to vary sinusoidally with rotor position so the resultant magnetic field of the stator rotates with the rotor field at a constant optimum torque angle (leading for forward torque and lagging for reverse torque). The system includes a rotor position transducer that provides signals for each motor phase which vary sinusoidally with rotor angle for synchronous control of current in the associated stator winding, circuits to extract speed and direction, polarity, and relative amplitude from said signals, means to multiply said amplitudes by a variable which commands stator current levels, servo loops (each comprised of an operational amplifier, a pulse duration modulator, switching logic, and a current sensor) that control current in each stator winding in synchronism with rotor position and in response to forward drive, brake, and reverse drive commands and the commanded current levels; plus a circuit to adapt rotor excitation to stator current and motor speed, and an interlock including means to interpose regenerative braking whenever a motor drive command is received opposite to the motor rotation.

Apparatus and method for indicating condition of a rotating body

Abstract: Apparatus and method particularly adapted for detecting over and/or under inflated conditions in a wheel structure of the type comprised of a pneumatic tire mounted on a wheel rim. A generator unit is mounted to the wheel generally coaxial of the axis of wheel rotation and is constructed such that the generator rotor is operably journalled within the generator stator in a manner facilitating rotation of the rotor independently of the remainder of the generator unit and wheel itself. One side of the rotor is weighted so that as the wheel and generator unit are rotated, the rotor disposition remains generally stationary due to the influence of gravity forces on the weighted area. The relative rotation thus achieved between stator and rotor causes a voltage to be induced in the stator field winding which is utilized to energize a small radio transmitter mounted on the wheel with the generator unit. Pressure sensing means communicating with the tire controls energization of the transmitter in response to a predetermined tire pressure condition. The transmitted radio signal is then received by a receiving unit spaced remote from the wheel to cause energization of convenient indicating means located in the vehicle to show that the predetermined air pressure condition has been detected.

Device for compensating synchronous disturbances in the magnetic suspension of a rotor

Abstract: A device is disclosed for compensating synchronous disturbances in the magnetic suspension system of a rotor which is supported by a radial electromagnetic bearing and which has means associated therewith for detecting the radial position of the rotor, comprising a servo-circuit for connection between the detecting means and windings of the electromagnetic bearing and including a circuit for the control of the current supply to the windings in response to signals from the detecting means to keep the rotor in a pre-determined radial position. The servo-circuit is provided with means for filtering the signals supplied by the detecting means between the latter and the control circuit, the filtering means having at least one band rejection filter centered on a frequency which is a direct function of the speed of rotation of the rotor.

Automatic approach to hover system

Abstract: In a helicopter having an automatic pilot system for controlling the main rotor collective pitch, main rotor longitudinal and lateral cyclic pitch, and tail rotor collective pitch, in response to inputs provided from normal sensors, navigational instruments and controls, (which include among others as is known, doppler radar, a pilot panel, an air speed indicator, a radar altimeter, a barometric altimeter and a longitudinal accelerometer), commands to control automatic approach to a desired hover position are provided to the autopilot system in response to signals normally supplied by a TACNAV unit as well as the sensors, navigational units and controls; controls are provided for altitude and rate of descent, so as to terminate in hover at a desired altitude, as well as for turns, courses, and speed so as to approach the desired point of hover upwind and to decelerate in a controlled fashion to hover.

Rotary steam engine

Abstract: A unidirectional rotary expansion steam power unit which is free from external valving arrangements and independent starting mechanisms, and which is adapted for multiple use in a system selectively using direct energization and compounding of the units. The power fluid is supplied through a hollow rotor, and is conducted to working chambers and exhausted therefrom by strategically located passages in the walls of a housing, under the control of seal means carried by the rotor.

Rotary energy converter with respiring chambers

Abstract: A rotary energy converter has a rotor provided with a plurality of hinged vanes and centrally mounted within a stator having a generally circular inner wall surface formed with one or more vaulted bays and corresponding abutments. As the rotor rotates within the stator, the hinged vanes are urged outwardly by centrifugal force into wiping contact with the stator inner wall, and are alternately extended and retracted, as the vanes encounter the vaulted bays and abutments to provide a respiring chamber between each pair of adjacent vanes. In one preferred form, the energy converter is shown as a rotary internal combustion engine having at least two vaulted bays, one of which constitutes a fuel inlet and compression bay, and the other of which constitutes a combustion expansion bay with an ignition station located between said bays. Rotor end corner seals are provided between the rotor and the stator end plates and oil-lubricated sliding seals are formed by the stator inner wall surface and the engaging vane surfaces, thereby eliminating the necessity for use of conventional stationary seals. A fuel injection system is actuated and controlled by the respiration of each chamber to provide comparatively low temperatures of combustion.

Vertical take-off and landing aircraft

Abstract: A vertical take-off and landing aircraft features an improved tail-lifting rotor and rotor directional controls. A new type of suction pressure jet-mechanical-flap rotor blade with a higher coefficient of lift is employed. The aircraft has a mechanism for loading and unloading passengers and a more efficient method of handling baggage and cargo. A much more efficient utilization of space in the fuselage is achieved through a reduced height passenger space and overhead rotor storage compartment.

Rotor means for an aircraft

Abstract: A rotor arrangement for an aircraft comprising two coaxially counter-rotatable rotators, each rotor being journaled freely rotatable about an imaginary axis of rotation common to both rotors on or through a fuselage part or a support member, each fuselage part or support member being either rigidly connected to or journaled on the fuselage, each rotor together with the other respective rotor or with the component part of the support member or fuselage part supporting the first mentioned rotor constituting an integral part of an electromotor by forming the counteracting parts of the electromotor ("rotor" and "stator") which rotate relative to one another by securing a plurality of poles of the electromotor to the respective rotor and by arranging on the other counter-rotating rotor or on the component part of the support member or fuselage part supporting the first mentioned rotor the corresponding poles of the electromotor facing toward the poles of the respective rotor such that a reciprocal field effect exists, at least the poles provided on one rotor or on the respective component part of the support member or fuselage part being electrically connected to a current generator which produces a frequency current.