5698results about "Asynchronous induction motors" patented technology

The invention includes an electric machine having a rotor, stator and at least one winding in the stator adapted to conduct a current, and a secondary winding, electrically isolated from the first winding and inductively coupled to the first winding, which may be used to control at least one of the output voltage and current of the first winding.

The torque of a motor operated by an inverter circuit is controlled to allow maximum torque in the motor when the motor is stalled or at low rotation speeds. Control is accomplished by providing a switching frequency to the motor at a first switching frequency, detecting a rotation speed of the motor, and switching the current to the motor to a second switching frequency when the rotation speed of the motor drops to a predetermined slow rotation speed. The second switching frequency is less than the first switching frequency.

A system and method for powered surgical handpiece capable of powering various micro-cutting instruments is described. The system is comprised of a controller adapted for controlling / interfacing with a powered surgical handpiece based upon user-defined procedural information. A data entry device is used for entering the user-defined procedural information used by the controller for configuring and operating the motor control system.

An electrical hand tool machine (1) having a motor switch (2) configured as a button and a current regulator (4) disposed in the current circuit of an electrical motor (3), having a soft-start input (5), in whose branch current a timing capacitor (6) is arranged. A current-direction-dependent element (7) is arranged between the soft-start input (5) and the capacitor (6).

An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.

A rotary sensor that outputs two analog signals, such as one sine wave and one cosine wave and has multiple periods within one period of the electrical angle of a motor is employed. The motor is energized at each position for a specified length of time upon its startup by using multiple electrical angles corresponding to the multiple candidate absolute angles obtained from the rotary sensor signal as the initial position of the motor, and the electrical angle at which the motor acceleration becomes maximum is determined as the absolute angle. While the motor drive is in operation, on the other hand, the phase difference Δθ between the phase of the motor at the counter electromotive voltage and the control phase is directly computed from the parameters of the motor, sensed current, voltage command and angle speed so as to correct the shifted position. A high-efficiency motor drive unit with improved maintainability of rotary sensor and improved accuracy of sensing the magnet pole position of a permanent magnet synchronous motor that accelerates and decelerates very quickly in a wide range of speed is realized.

A method of testing an electric motor that is adapted to provide a desired electric motor output torque to a vehicle powertrain system comprising an engine and the electric motor which are operatively and selectively coupled to a transmission. The method includes the steps of determining an initial motor speed of the electric motor, determining a motor torque command as a function of the initial motor speed, applying the motor torque command to the electric motor to produce an output torque from the electric motor, measuring a resultant motor speed of the electric motor and establishing a motor status as a function of the resultant motor speed. The method may be implemented as a computer control and diagnostic algorithm.

PCT No. PCT / JP96 / 02929 Sec. 371 Date Jun. 25, 1998 Sec. 102(e) Date Jun. 25, 1998 PCT Filed Oct. 9, 1996 PCT Pub. No. WO97 / 26700 PCT Pub. Date Jul. 24, 1997A motor mounted in a vehicle having a winding comprising a flat band-like copper wire is provided. The winding is wound on a projection that extends radially inward of a stator. The winding includes a first band-like section that is adapted to be wound on a radially inward portion of the projection of the stator. The winding also includes a connection section that is continuous with one longitudinal end of the first band-like section and extends radially outward along the radial direction of the projection of the stator. The winding further includes a second band-like section that is adapted to be wound on a radially outward portion of the projection of the stator. One longitudinal end of the second band-like section is continuous with the connection section. The first band-like section extends from a radially inward portion of the connection section and the second band-like section extends from a radially outward portion of the connection section. The first and second band-like sections extend from the connection section in opposite directions.

An AC generator for a vehicle including a rotor with a fan, a stator disposed around the outer periphery of the rotor, and a frame. The stator includes a laminated core having a plurality of slots, a plurality of electric conductors in the slots, and an insulator. There is a gap between the electric conductors and the insulator in a diametrical section of the slots, and an area ratio of the gap with respect to the sectional area of the slots is not more than 25%. A portion of the electric conductor positioned within the slot has a substantially rectangular shape along the shape of the slot.

Machines useful for wind turbine and ship propulsion purposes include a wind turbine generator or a ship propulsion motor with two concentric air gaps. In one embodiment, the machine includes a rotor with an inner rotor core and an outer rotor core; and a double-sided stator with an inner stator side and an outer stator side. The double-sided stator is concentrically disposed between the inner rotor core and the outer rotor core.

A permanent magnetically excited electrical rotary drive for a blood pump is proposed, comprising a permanent magnetic rotor and a stator, said stator comprising a drive winding having at least two loops for the production of a magnetic drive field which produces a torque on the rotor, with each loop belonging to a different electrical phase, furthermore comprising a setting device which supplies each loop in each case with a phase current or in each case with a phase voltage as a setting parameter, with the setting device comprising a separate power amplifier for each loop so that the setting parameter for each loop can be regulated independently of the setting parameter for the other loops.

A low inductance electrical machine that may be used as an alternator or motor with low armature inductance is disclosed. Arrangements of complementary armature windings are presented in which the fluxes induced by currents in the armature windings effectively cancel leading to low magnetic energy storage within the machine. This leads to low net flux levels, low core losses, low inductance and reduced tendency toward magnetic saturation. The inclusion of additional gaps in the magnetic circuit allows for independent adjustment of air gap geometry and armature inductance. Separately excited field arrangements are disclosed that allow rotor motion to effect brush-less alternator or brush-less motor operation. An exemplary geometry includes a stator including two annular rings and a concentric field coil together with a rotor structure separated from the stator by four air gaps.

An AC generator for vehicles includes a field rotor, a stator disposed around said field rotor and a frame for supporting the rotor and the stator. The stator has a laminated core having a plurality of slots, aluminum conductors housed in the slots, and an electric insulator. The aluminum conductor is constituted by in-slot portion and a crossover portion for connecting an in-slot portion in one slot to another in-slot portion in a different slot to provide a winding as a whole. The frame is provided with a plurality of windows substantially in a whole periphery thereof at portions encircling the crossover portions and substantially in an outer diametrical direction opposite to the crossover portions.

A disk drive is disclosed comprising a spindle motor comprising a plurality of windings for rotating a disk. The spindle motor is rotated by commutating the windings over a plurality of commutation states, wherein audible noise generated by the disk drive is reduced by phase modulating the commutation interval. Further audible noise reduction is achieved by modulating a current applied to the windings which substantially reduces discontinuities in the torque output of the spindle motor caused by phase modulation of the commutation intervals.

Cordless power tools include a pistol housing having an upper portion that merges into a downwardly extending handle, a DC motor residing in the upper portion of the housing, the DC motor having a rotor that drives an output shaft; a torque transducer on board the tool in communication with the output shaft; and a dynamic motor control circuit residing in the housing in communication with the motor and torque transducer. The dynamic motor control circuit includes a Kelvin resistor in communication with the motor for measuring motor current and digital hall switches in communication with the motor for measuring motor speed. The motor current can vary by at least 100 A during operation.

A reluctance motor is provided that reduces leaking magnetic flux. To generate magnetic flux between adjacent magnetic poles in a rotor 2, permanent magnets 4 are disposed in approximate centers of split magnetic paths near a borderline area between two magnetic poles in an internal portion of the rotor. Further, each of slots 8 in a stator 1 is wound with a coil of a corresponding phase such that the vector phase and amplitude expressed by the products of the number of coil turns and the amount of passing current, namely, ampere-turns, become almost identical for each of the slots. By reducing leaking magnetic flux according to this arrangement, generated torque can be increased. As the rotor mechanical strength is enhanced, the rotor can be safely driven at a higher speed. A practical motor is obtained that simultaneously achieves improved motor characteristics and reduced torque ripples.

To provide an aircraft propulsion system which can secure the optimum thrust and thrust vector for flight conditions, as well as the optimum sectional area for the engine, and which is highly compatible with the environment. An electrical generator is coupled to a turbofan engine, the electrical generator is driven by output power of the turbofan engine to output electric power, and an electromagnetic driving fan is driven by the electric power. On the other hand, after bringing each of coils in the electromagnetic driving fan to a superconductive state, liquid hydrogen is introduced to a heat exchanger, collects the energy of exhaust as heat, is then vaporized, and thereafter supplied to a combustor and to a fuel cell. Further, the electromagnetic driving fan is changed in its rotational phase by a rotating mechanism portion, is made movable in a width direction of a wing and a wing chord direction by a slide mechanism portion, and can be stored inside or outside the wing by a storage mechanism portion.

A control apparatus for a multi-phase rotary machine includes a control unit and a plurality of power supply systems including respective inverter units. When a short-circuiting failure occurs in one of the systems due to an ON-failure in any one of FETs in an inverter unit of the failure system, the control unit stops driving of the rotary machine by bringing all the FETs in the failure system into the OFF state. The control unit controls FETs of the non-failure system such that a brake torque generated in the failure system is cancelled or the influence of the brake torque exerted on the driving of the motor is reduced.

The present invention provides a novel dual-rotor, radial-flux, toroidally-wound, permanent-magnet machine. The present invention improves electrical machine torque density and efficiency. At least one concentric surface-mounted permanent magnet dual-rotor is located inside and outside of a torus-shaped stator with back-to-back windings, respectively. The machine substantially improves machine efficiency by reducing the end windings and boosts the torque density by at least doubling the air gap and optimizing the machine aspect ratio.

An electromechanical actuator (EMA) is provided. The EMA includes a threaded output ram connectable to a mechanical component and at least one motor module engageable with the output ram for controllably translating the output ram along a linear axis of the output ram. The actuator further includes a torque sensing adaptive control (TSAC) system for monitoring torque within the motor module. The TSAC generates a disengagement command signal when the TSAC system determines torque within the motor module is outside an allowable motor module torque range. The disengagement command signal initiates disengagement of the motor module from the output ram.

A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck. The control circuit for the power tool is operable in a ratcheting or pulse mode that causes the output spindle to rotate in discrete incremental amounts. Corresponding methods for controlling the operation of the electric motor of a power tool are also disclosed.

An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.

A powered tool for performing surgical procedures. The tool includes a handpiece in which a power generating unit is housed. A control member is mounted to the handpiece. The control member is mounted to the handpiece so that the orientation of the control member can be selectively set relative to the point to which it is mounted to the handpiece and so it can move relative to a reference point on the handpiece. A control module monitors the orientation of the control member and its position relative to the reference point. Based on the control member orientation and position, the control module generates signals to regulate the operation of the power generating unit. When the power generating unit is a motor, the control module generates signals to ensure that the maximum speed at which the motor can be driven is less than the no load speed.

Disclosed is a control apparatus for a hybrid vehicle having an engine, a drive motor (3) that regenerates power, and an electric power storage device (6) that gives / receives power to / from the drive motor (3). The control apparatus includes power consumption means (2) for consuming power; a sensor (26, 27) that detects a state of charge of the electric power storage device; means (18, 23, 51) for detecting a driving state of the vehicle; and a controller (9). The controller (9) is programmed to calculate a chargeable energy amount Ecap in the electric power storage device (6) on the basis of a difference between a fully charged state of the electric power storage device and the detected state of charge; set a power |Pgen0| regenerated by the drive motor (3); calculate a chargeable power Pmax in the electric power storage device according to the detected state of charge; calculate a regenerated energy E resulting from regenerative braking from the detected driving state of the vehicle; calculate a charging power limit Pgenlmt according to the calculated regenerated energy E; and control the power consumption means (2) to consume a power equal to a difference between the power |Pgen0| regenerated by the drive motor (3) and the charging power limit |Pgenlmt| when the calculated regenerated energy E is greater than the chargeable energy amount Ecap in the electric power storage device and when the charging power limit |Pgenlmt| is smaller than the chargeable power |Pmax|.

A method of controlling a current command by comparing voltage with a set value needs to vary the set value depending on voltage fluctuation, which involves taking a complicated control. A vector controller for a permanent-magnet synchronous electric motor, according to the present invention, can realize with a simplified configuration a field-weakening operation in a one-pulse mode in a high speed range by providing a current command compensator that corrects a current command by a corrected current command calculated based on a modulation index.

The present invention discloses small compact motor systems which may be located inside a vehicle drive wheel, and which allow a drive motor to provide the necessary torque with reasonable system mass. The motor systems of the invention utilize polyphase electric motors, and are preferably connected to appropriate drive systems via mesh connections, to provide variable V / Hz ratios. In one embodiment the stator coils are wound around the inside and outside of the stator. In a further embodiment, the machine contains a high number of phases, greater than three. In a further embodiment, the phases are connected in a mesh connection. In a further embodiment, each half-phase is independently driven to enable second harmonic drive for an impedance effect. Improvements are apparent in efficiency and packing density.