Braking Patents (Class 318/703)
  • Patent number: 11511387
    Abstract: An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder (1) is provided with a motor (6), an inverter circuit (43) for supplying electric current to the motor (6), and a controller (50) for controlling the inverter circuit (43). When generating an electric braking force on a motor (6), the rotation speed of which exceeds a specified rotation speed, the controller (50) performs a first braking control of continuously turning on lower arm-side switching elements (Q4-Q6) of the inverter circuit (43), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q4-Q6).
    Type: Grant
    Filed: October 27, 2017
    Date of Patent: November 29, 2022
    Assignee: Koki Holdings Co., Ltd.
    Inventors: Takuya Yoshinari, Kazutaka Iwata
  • Patent number: 11303231
    Abstract: A motor driving control apparatus according to an embodiment includes a motor driving unit that selectively energizes the three-phase coils of a motor; a motor control unit that switches an energizing phase of the coils in a predetermined order, the energizing phase being a phase to which the motor driving unit energizes, by outputting a driving control signal to the motor driving unit; a brake control unit that outputs a brake control signal; an interphase short-circuiting unit that is connected to the coils, and that short-circuits the coils in each of three pairs that are different combinations of two coils of the coils, in response to a short-circuiting signal; and a short-circuiting signal output unit that is connected between the interphase short-circuiting unit and the coil, and that outputs the short-circuiting signal to the interphase short-circuiting unit when an input of the brake control signal is received.
    Type: Grant
    Filed: January 8, 2019
    Date of Patent: April 12, 2022
    Assignee: MINEBEA MITSUMI Inc.
    Inventors: Katsunori Yamamoto, Hiroyuki Kato
  • Patent number: 10928144
    Abstract: The present invention is directed to a load bearing direct-drive system and a variable process control system for efficiently managing the operation of fans in a cooling system such as a wet-cooling tower, air-cooled heat exchanger (ACHE), HVAC system, blowers and centrifugal blowers, mechanical towers or chiller systems. In one embodiment, the load bearing direct-drive system comprises a load bearing torque multiplier device having an output rotatable shaft connected to a fan, and a load bearing motor comprising a rotatable shaft that drives the load bearing torque multiplier device.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: February 23, 2021
    Assignee: PRIME DATUM DEVELOPMENT COMPANY, LLC
    Inventors: Patrick M. Rollins, George M. Lucas
  • Patent number: 10455973
    Abstract: The invention relates to a milk-frothing device with a dynamic mixing unit having a stator and a rotor which can be set in rotation relative to the stator, rotor and stator being configured such that milk and air can be conducted firstly to the dynamic mixing unit, subsequently, for frothing-up in the dynamic mixing unit, can be subjected multiple times to a shearing effect by rotation of the rotor relative to the stator and finally can be discharged out of the dynamic mixing unit.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: October 29, 2019
    Assignee: WMF GROUP GmbH
    Inventors: Sander Dollner, Thobias Kuchler, Jochen Gussmann
  • Patent number: 10353410
    Abstract: Systems and methods for automatically adjust control parameters of a TRS according to local, regional and/or federal regulations on emissions, noise and/or other requirements applicable to a particular location and/or time, are provided. When the TRS is operating within a predefined geographic region at a specific time, control parameters or an operation mode of the TRS can be automatically adjusted so that emission and/or noise from the TRS can be compliant with the regulations applicable to that predefined geographic region.
    Type: Grant
    Filed: December 27, 2013
    Date of Patent: July 16, 2019
    Assignee: THERMO KING CORPORATION
    Inventors: Scott Robert Bates, Robert Michael Lattin, Erich Albert Lucht
  • Patent number: 10101396
    Abstract: A machine control system and a method of detecting a current sensor malfunction include obtaining a first current signal from a first current sensor corresponding with a first phase of a multi-phase machine, obtaining a second current signal from a second current sensor corresponding with a second phase of the multi-phase machine, and obtaining a position signal indicating an angular position of a rotor of the multi-phase machine corresponding with values of the first current signal and the second current signal. A determination is made of whether the current sensor malfunction occurred in the first current sensor or the second current sensor based only on the values of the first current signal and the second current signal at four of the angular positions of the rotor.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: October 16, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
  • Patent number: 9647581
    Abstract: A motor drive according to the present invention has a dynamic braking circuit. The motor drive includes a motor drive control circuit for applying a voltage to windings of a synchronous motor and the dynamic braking circuit for a predetermined time by switching power transistors connected to a direct current power supply, a current detection circuit for detecting a current value outputted from the power transistor, and a failure determination circuit for determining the presence or absence of a failure in the dynamic braking circuit from the current value detected by the current detection circuit and a predetermined threshold value. When the presence or absence of a failure in the dynamic braking circuit is detected, the resistance of the dynamic braking circuit is changed.
    Type: Grant
    Filed: January 26, 2016
    Date of Patent: May 9, 2017
    Assignee: Fanuc Corporation
    Inventors: Sou Saitou, Tsutomu Shikagawa
  • Publication number: 20150130382
    Abstract: A controller for a brushless direct-current motor having an upstream converter, which has a half-bridge having a pair of switching means for each phase winding of the motor, includes a measuring device or has a signal connection to a measuring device. The measuring device is associated with a half-bridge and by means of the measuring device, the induced voltage, the counterelectromotive force of a phase winding, can be detected for rotor position detection in the current-free state, for which purpose the controller, in an operating mode that causes the braking and in which the switching means cause a short circuit of the phase windings, briefly opens the switching means associated with the measuring device in order to determine a rotor motion.
    Type: Application
    Filed: April 18, 2013
    Publication date: May 14, 2015
    Inventor: Markus Schüssler
  • Patent number: 9007011
    Abstract: A driving control device of a brushless motor includes an inverter circuit having: first arm-side switching elements that are connected between respective phases of respective armature coils of the brushless motor and one terminal of a power supply; and second arm-side switching elements that are connected between respective phases of the respective armature coils and the other terminal of the power supply, and a control unit, wherein, in a short-circuit braking according to a short-circuit braking signal, the control unit outputs a signal of turning off all the first arm-side switching element and outputs a signal of controlling the at least one of the second arm-side switching elements to perform a switching operation and turning on the other second arm-side switching elements.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: April 14, 2015
    Assignee: Minebea Co., Ltd.
    Inventor: Masato Aoki
  • Publication number: 20150042259
    Abstract: The present disclosure relates to an emergency stop method for hybrid construction equipment and a brake control device, and more particularly, to an emergency stop method for hybrid construction equipment and a brake control device, which may confirm a failure occurrence location of the hybrid construction equipment, absorb inertial energy of the swing body using several functions for each generated failure location so as to stably stop the swing body in an emergency manner, and when the failure occurs in the hybrid construction equipment, create the brake pattern by using the swing speed or the front information, control a brake of the swing body by controlling a voltage control valve or a hydraulic valve in accordance with the created brake pattern, such that a user may smoothly stop the swing body in accordance with a desired stop speed profile.
    Type: Application
    Filed: December 27, 2012
    Publication date: February 12, 2015
    Inventors: Sang Il Kim, Kyeong Keun Kim, Byung Il Kang
  • Publication number: 20140321001
    Abstract: A current detection circuit for detecting a maximum current value in a three-phase motor includes an identifier configured to identify a maximum current phase having the maximum current value among phases of the motor, and a detector configured to detects the maximum current value by summing current values of phases other than the maximum current phase when the current direction in the maximum current phase is a predetermined first direction.
    Type: Application
    Filed: April 29, 2014
    Publication date: October 30, 2014
    Applicant: Rohm Co., Ltd.
    Inventor: Takashi Yoshiya
  • Patent number: 8736204
    Abstract: Apparatus for transferring power between an electricity network (UP) operating on alternating-current electricity and a multiphase electric machine (M2, M3), which apparatus comprises low-voltage power cells (CS, C11 . . . CN6) operating on a cascade principle, which power cells comprise a single-phase output connector (OUT), and at least one transformer (TA, T1 . . . TN), comprising for each power cell connected to it a single-phase or multiphase winding dedicated to the specific power cell, which transformer comprises at least one additional winding (WA, WB1 . . . WBN) connected to the same magnetic circuit as the other windings for the purpose of at least one auxiliary circuit, which can be connected to the aforementioned additional winding.
    Type: Grant
    Filed: January 3, 2012
    Date of Patent: May 27, 2014
    Assignee: Vacon Oyj
    Inventors: Nicklas Södö, Risto Komulainen
  • Patent number: 8704468
    Abstract: An electrodynamic braking device for a universal motor is proposed, wherein during a braking operation a field winding is supplied from a network, and an armature is directly short-circuited, and a braking operation is carried out using a program of a controller of a control electronics system, whereby good braking is achieved with relatively low brush wear. Such an electrodynamic braking device is advantageously applied in a power tool equipped with a dangerous tool.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: April 22, 2014
    Assignee: Robert Bosch GmbH
    Inventor: Hans Hermann Rottmerhusen
  • Patent number: 8624541
    Abstract: Regulating the speed of a two-phase switched reluctance machine (TPSRM) rotor includes selecting either a motoring mode or braking mode of operation for the TPSRM, regulating the rotor speed, when the motoring mode is selected, using a control signal cooperatively produced by a speed control feedback loop and a current control feedback loop; and regulating the rotor speed, when the braking mode is selected, using a control signal produced by the current control feedback loop without the cooperation of the speed control feedback loop. The speed control feedback loop uses an established speed control signal and a signal indicative of the rotor's speed to dynamically adjust a first parameter governing the control signal. The current control feedback loop uses an established current control signal and a signal indicative of the current flowing through a stator winding of the TPSRM to dynamically adjust a second parameter governing the control signal.
    Type: Grant
    Filed: May 1, 2012
    Date of Patent: January 7, 2014
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Krishnan Ramu, Keunsoo Ha, Sung-Yeul Park
  • Publication number: 20130330207
    Abstract: A controller that performs pulse width modulation control of a three-phase inverter circuit includes a three-phase modulation voltage command value generation unit, a two-phase modulation voltage command value generation unit, a voltage command switching unit, and a PWM signal output unit. The voltage command switching unit switches a voltage command value to a two-phase modulation voltage command value when a determination value becomes larger than or equal to a first threshold value, and switches the voltage command value to a three-phase modulation voltage command value when the determination value becomes smaller than a second threshold value, which is smaller than the first threshold value.
    Type: Application
    Filed: June 3, 2013
    Publication date: December 12, 2013
    Inventors: Kazushige NAKAJIMA, Tokuji TSUNEMATSU, Shingo NAKAGAWA
  • Patent number: 8587231
    Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: November 19, 2013
    Assignee: Black & Decker Inc.
    Inventor: Pradeep M. Pant
  • Patent number: 7898196
    Abstract: A motor driving apparatus for driving and braking a motor equipped with a brake comprises a motor/brake driving DC power supply which is used both as a motor driving power supply and as a brake driving power supply, wherein when the motor/brake driving DC power supply is being used as the motor driving power supply, a voltage conversion circuit via which a voltage supplied from the motor/brake driving DC power supply is applied to the brake feedback-controls the voltage applied to the brake. This configuration serves to reduce the loss (due to temperature rise) in the brake coil of the motor being driven to move a robot arm.
    Type: Grant
    Filed: October 14, 2007
    Date of Patent: March 1, 2011
    Assignee: Fanuc Ltd
    Inventors: Shinichi Horikoshi, Naoyuki Suzuki, Tsutomu Shikagawa
  • Patent number: 7825619
    Abstract: A method for controlling stopping of a vibration generating stepping motor is a method for controlling the stopping of an vibration generating stepping motor by a control unit, characterized in that the method includes: stopping a supply of a driving pulse to the vibration generating stepping motor while applying a driving voltage to the vibration generating stepping motor; applying the driving voltage to the stepping motor, which does not completely stop, for an optimum braking time according to a motor configuration of the stepping motor, so as to brake the stepping motor; and stopping the applying of the driving voltage to the stepping motor which is rotating under inertia after the elapse of the optimum braking time.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: November 2, 2010
    Assignee: Minebea Motor Manufacturing Corporation
    Inventors: Masaki Matsubara, Kazuaki Sato, Mikio Umehara, Toshiaki Tsuzaki
  • Patent number: 7675254
    Abstract: Disclosed is an electric drive for a vehicle, which is used as a main drive or a hybrid drive. The electric motor of said drive is embodied as a special type of reluctance motor or series wound motor. The rotor of the reluctance motor and the inverse speed motor is provided with an excitation winding to which a transistor is assigned that allows the motor to be braked in a sensitive manner so as to control the field current. The braking current is fed to the source of current by switching operation of the motor during generator operation.
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: March 9, 2010
    Assignee: Audi AG
    Inventor: Hans Hermann Rottmerhusen
  • Patent number: 7615947
    Abstract: A motor driving device includes a brake mode control section for starting, when a brake instruction for a motor, braking of the motor in a reverse brake mode and then switching the reverse brake mode to a short brake mode; a cycle start detection section for receiving a rotation signal and detecting a start of a cycle of the rotation signal for each cycle; and a counter for performing, when the start of the cycle of the rotation signal is detected by the cycle start detection section, a count operation from an initial value. In the motor driving device, the brake mode control section detects that a value of the counter exceeds a threshold and performs switching from the reverse brake mode to the short brake mode with a delay from the detection.
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: November 10, 2009
    Assignee: Panasonic Corporation
    Inventor: Shuji Tamaoka
  • Publication number: 20090193923
    Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.
    Type: Application
    Filed: March 19, 2009
    Publication date: August 6, 2009
    Applicant: DENSO Corporation
    Inventors: Yasuhiro Nakai, Shigeru Kamio, Kenichi Fujiki
  • Patent number: 7511438
    Abstract: A system and method are provided whereby at least two motors driven by an inverter coupled to a DC bus are configured to alternate between regenerative and injection braking such that at least one motor is placed in regenerative braking mode and at least one motor is placed in motoring mode. Energy is simultaneously placed on and removed from the DC bus in a manner allowing a large current to flow in as many motors as possible, for fast stoppage of load inertia. At least one motor may be placed in regenerative braking mode and at least one motor in DC injection mode, such that energy is simultaneously placed onto and removed from the DC bus, respectively. Further, a single motor may be is alternated between regenerative braking and DC injection braking, such that energy is alternately placed onto and removed from the DC bus, respectively.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: March 31, 2009
    Assignee: Reliance Electric Technologies, LLC
    Inventor: Michael J. Melfi
  • Publication number: 20090026998
    Abstract: A motor is controlled to always consume power supplied from a power supply system or not to supply power to the power supply system, by performing control to advance or delay a phase of a 3-phase current flowing in the motor or to reduce a percentage of the generated torque with respect to an effective value of the 3-phase current of the motor, or by applying a d-axis current to the motor.
    Type: Application
    Filed: July 25, 2008
    Publication date: January 29, 2009
    Applicant: HITACHI, LTD.
    Inventors: Kentaro Ueno, Mitsuhide Sasaki, Toshiyuki Innami
  • Patent number: 7466091
    Abstract: The invention relates to a vehicle electric drive system. There is a need for a brake responsive vehicle electric drive system. A vehicle electric drive system includes an internal combustion engine, an electric motor/generator driven by the engine, and drive wheels driven by a traction motor/generator. The motor/generators are controlled by a control system which receives signals from an operator speed control member, wheel speed sensors, and a pair of brake pedal position sensors, each connected to a corresponding left or right brake pedal. In response to operation of the brake pedals, the controller coordinates operation of the electric drive system with operation of the brake pedals.
    Type: Grant
    Filed: February 9, 2007
    Date of Patent: December 16, 2008
    Assignee: Deere & Company
    Inventors: Arun Kumar Seksaria, Mervin Peter Kizlyk, Robert Eugene Kasten
  • Patent number: 7268507
    Abstract: A DC power supply, a DC motor driven by DC voltage outputted from the DC power supply, and a control unit outputting a drive control signal to drive the DC motor are provided. A motor drive switch is provided between the DC power supply and the DC motor, and a brake switch is connected to a positive input terminal of the DC motor. The motor drive switch is on while receiving the drive control signal and outputs an output current monitor signal while current is being applied to the motor drive switch. The brake switch is configured to operate faster than the motor drive switch and is off while at least one of the drive control signal and the output current monitor signal is on. Accordingly, when the drive control signal is supplied, the brake switch is turned off, and then the motor drive switch is turned on.
    Type: Grant
    Filed: October 25, 2005
    Date of Patent: September 11, 2007
    Assignee: Yazaki Corporation
    Inventor: Yoshihiro Kawamura
  • Patent number: 7215093
    Abstract: A motor drive circuit includes a first transistor. The collector of a second transistor is connected to the emitter of the first transistor in series. A motor is connected to a connection point between the first and second transistors. A first brake control circuit turns off the first transistor and turns on the second transistor in accordance with a brake operation instruction signal. A second brake control circuit forces the first transistor to be turned OFF in accordance with the brake operation instruction signal independently from the first brake control circuit.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: May 8, 2007
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Kaoru Usui, Tomomitsu Oohara
  • Patent number: 6919705
    Abstract: A drive system, includes a motor having a neutral terminal, a converter, which has a voltage intermediate circuit and is electrically connected to the motor, a switching device, and a holding brake, which is mechanically connected to the motor. The holding brake has a first terminal, which is connected to the neutral terminal of the motor, and a second terminal, which is connected with a negative busbar of the voltage intermediate circuit via the switching device.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: July 19, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventor: Albrecht Donat
  • Patent number: 6867561
    Abstract: An electrical machine comprises a rotor without windings, a stator having an armature winding 24, 25 and a field winding 10 for generating a magnetomotive force in a direction extending transversely of the magnetomotive force generated by the armature winding. An electronic circuit 40 is provided for controlling the current in the armature winding 24, 25 such that periods in which a magnetomotive force in one direction is associated with a first current pulse alternate with periods in which a magnetomotive force in the opposite direction is associated with a second current pulse. A position sensor is provided for monitoring the rotational position of the rotor and for supplying output signals at a rate dependent on the speed of rotation of the rotor. Furthermore a control system supplies control signals to the circuit 40 to control the current in the armature winding 24, 25 in response to the output signals.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: March 15, 2005
    Assignees: Black & Decker, Inc., University of Warwick
    Inventors: Charles Pollock, Helen Geraldine Phyllis Pollock, Richard Thomas Walter
  • Patent number: 6788021
    Abstract: A control algorithm provides automatic control of the turn-on angle used to excite the switched-reluctance motor (SRM). The control algorithm determines the turn-on angle that supports the most efficient operation of the motor drive system, and consists of two pieces. The first piece of the control technique monitors the position of the first peak of the phase current (&thgr;p) and seeks to align this position with the angle where the inductance begins to increase (&thgr;m). The second piece of the controller monitors the peak phase current and advances the turn-on angle if the commanded reference current cannot be produced by the controller. The first piece of the controller tends to be active below base speed of the SRM, where phase currents can be built easily by the inverter and &thgr;p is relatively independent of &thgr;m. The second piece of the controller tends to be active above base speed, where the peak of the phase currents tends to naturally occur at &thgr;m, regardless of the current amplitude.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: September 7, 2004
    Assignee: Dana Corporation
    Inventors: Yilmaz Sozer, David A. Torrey, Erkan Mese
  • Patent number: 6741050
    Abstract: A control method and a switching circuit for braking an electronically commutated electrical motor, wherein operation is in a phase period (T) of an inverter relative to at lest one winding, sequentially, both in a motoring mode and a generating operating mode using various cycles (t1-t2, t3-t4) beginning with zero, such that the driving and braking torques associated with the cycles (t1-t2, t3-t4) produce a resultant braking moment averaged over the phase period (T).
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: May 25, 2004
    Assignee: Hilti Aktiengesellschaft
    Inventors: Walter Wissmach, Rudolf Bauer, Vilmos Török
  • Patent number: 6566839
    Abstract: The present invention is a method and apparatus that allows the torque of an electric motor to be increased allowing the motor to be operated at higher speeds and at higher torque without raising the supply voltage, thus allowing for a wider dynamic range of speed and torque to be realized. This is accomplished by connecting one or more capacitors in series with each motor winding, and selectively activating the capacitors at higher speeds where the frequency of the motor resonates with that of the capacitor(s). Switching a capacitor into the circuit with the motor in a particular frequency range allows higher currents to flow through the motor windings resulting in higher torque.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: May 20, 2003
    Assignee: Pelco
    Inventors: Daniel Robert DaSilva, John Pretzer, Glenn Waehner
  • Patent number: 6456032
    Abstract: A motor driver for drive-controlling a brushless motor being provided with a delay circuit that detects the motor pulse. When a stop signal is inputted, a transistor is activated, which in turn activates an electric brake to brake the brushless motor, while at the same time, the motor pulse detected by the motor driver is inputted to the delay circuit. After the stop signal is inputted, the motor pulse declines, which is detected by the delay circuit to activate the electromagnetic brake. The delay circuit is provided on the driver substrate for the motor driver.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: September 24, 2002
    Assignee: Itoh Electric Co., Ltd.
    Inventors: Kazuo Itoh, Toshiyuki Tachibana, Shigeki Fukata
  • Patent number: 5828195
    Abstract: Apparatus for braking either a linear or rotary electric motor having no permanent magnets comprising at least one position sensor for outputting an electrical characteristic representative of motor position and an electronic circuit for generating a pulsed control signal for controlling the braking of the motor. The electronic circuit of the present invention may be responsive to any emergency such as loss of line power, a motion controller failure, or actuation of a limit switch by a driven member.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: October 27, 1998
    Assignee: Universal Instruments Corporation
    Inventor: Andrew Zalesski
  • Patent number: 5793168
    Abstract: A circuit for driving a brushless dc motor includes an active deceleration circuit for rapidly slowing the motor. A phase locked loop senses a position of the rotor for commutating from a drive state to a next drive state in a sequence of drive states at an appropriate time for maintaining torque on the rotor in the direction of rotation. Thus, the rotor "chases" the energized windings. A speed control loop controls current in the windings and, thus, motor speed. When the speed of the motor exceeds a desired speed by more than a threshold amount, rather than commutating to a next drive state in the sequence, the circuit skips a commutation. By skipping one commutation, the current drive state is maintained while the rotor continues to turn, due to its own inertia, such that the rotor "passes up" the current drive state. This results in a torque on the rotor in a direction opposite rotation.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: August 11, 1998
    Assignee: Micro Linear Corporation
    Inventor: Mark R. Vitunic
  • Patent number: 5734241
    Abstract: A brushless motor includes a stationary member; a rotating member rotatably supported with respect to the stationary member; a stator provided in the stationary member and provided with a stator coil for generating current magnetic field under an exciting state; and a rotor magnet provided in the rotating member for obtaining a revolutionary power due to an electromagnetic mutual effect with the current magnet field of the stator coil. The rotor magnet is formed such that segment-shaped magnets are placed annularly with predetermined gaps circumferentially. The gaps are filled with a magnetic resin material.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: March 31, 1998
    Assignee: Nidec Corporation
    Inventors: Tadashi Okada, Akira Inui
  • Patent number: 5315226
    Abstract: A method and apparatus for controlling a synchronous motor with an AC voltage. A rated value proportional to a desired frequency of the AC voltage and related to a rotational speed of the synchronous motor is provided. The rated value is continuously added up in an accumulator to provide added-up signal values. The added-up signal values are employed for addressing stored function values in a function value memory, the function values representing at least one AC voltage. The addressed function values are read out from the function value memory and are converted into at least one AC voltage having the frequency corresponding to the rated value. The AC voltage is supplied to the synchronous motor for generating a rotary field such that the frequency of the AC voltage defines the rotational speed of the synchronous motor.
    Type: Grant
    Filed: January 13, 1993
    Date of Patent: May 24, 1994
    Assignee: Linotype-Hell AG
    Inventors: Ewald Fehlauer, Klaus Hofmann
  • Patent number: 4827204
    Abstract: In an electric motor with a damping device incorporating a disc-shaped damping mass which is freely rotatable and axially movable in relation to the driven element and consists at least partially of a mangetizable material, the damping mass is located within the range of a stray magnetic field (31) of the motor (11) and is pressed against a friction plate (28) located between the rotor (14) of the motor and the damping mass and rotating with the driven element as a result of the magnetic force of the stray field acting upon the mass.
    Type: Grant
    Filed: November 7, 1984
    Date of Patent: May 2, 1989
    Assignee: U.S. Philips Corporation
    Inventors: Romuald L. Bukoschek, Hugo Schemmann
  • Patent number: 4492903
    Abstract: A machine includes a rotor with a magnetic field produced therein that is fixedly oriented with respect to the rotor. The rotor is rotatably mounted within a stator which has a plurality of windings. Means are provided for applying voltage pulses to the stator windings. When voltage pulses are applied to the stator windings, there is a torque due to the interaction of a magnetic field produced in the stator windings and the rotor magnetic field that causes the rotor to rotate. A control system responds to voltage induced across unpowered stator windings by the rotating rotor magnetic field and controls application of the voltage pulses to the stator windings. The voltage pulse sequence, frequency, and duration are determined by the control system. The control system may also adjust the voltage pulse amplitude. The voltage pulses are applied to the stator windings in such a way that the machine operates at optimum efficiency and at a selectable speed over a wide range of loads and/or line voltages.
    Type: Grant
    Filed: December 8, 1980
    Date of Patent: January 8, 1985
    Assignee: Nu-Tech Industries, Inc.
    Inventors: John H. Knight, Milton S. Isaacson
  • Patent number: 4492910
    Abstract: In a method and apparatus for regulating the rotational speed of a motor having a rotor with magnetic poles and a stator with at least two coils, wherein during a first operational mode the sinusoidal voltage included in a first of the coils is digitized to produce first and second streams of rectangular pulses, the first pulse stream being compared with a reference frequency pulse signal as regards width and phase to generate accelerating or braking driving pulses supplied to the second coil, the second pulse stream being monitored to determine the rotational speed of the rotor and a second operational mode being instituted whenever the rotor speed falls below a predetermined value, in said second operational mode the rotor speed being accelerated through the application of driving pulses alternately to the first and second coils, the improvement wherein, following the switchover from the self starting mode to the nominial running mode of operation, during a transitional period for a specified time interval,
    Type: Grant
    Filed: April 20, 1983
    Date of Patent: January 8, 1985
    Assignee: Braun Aktiengesellschaft
    Inventor: Dan-Corneliu Radacanu
  • Patent number: 4486697
    Abstract: A reversing device for a two-pole single-phase synchronous motor (3) without a starting coil. The motor comprises a diametrically magnetized permanent-magnet rotor having a shaft that runs against elastic stops for reversing the direction of rotation, and a capacitor arranged in series with the stator exciter coil. The capacitor serves for improving the reversing operation and is dimensioned so that its reactance at the AC supply frequency is greater than the reactance of the exciter coil of the synchronous motor.
    Type: Grant
    Filed: May 20, 1983
    Date of Patent: December 4, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Gerhard Diefenbach, Erich Krainer
  • Patent number: 4441062
    Abstract: A missing pulse detector circuit is disclosed which includes a variable frequency VCO and a digital phase comparator. The phase comparator compares the phase of the VCO reference and the phase of a driving signal that drives a synchronous motor drive package. The output of the phase comparator is input to a loop filter to provide an error signal that controls the VCO frequency and phase. A second output on the phase comparator translates a phase difference into a pulse width. The pulse width is then input to an integrator circuit to delay the leading edge thereof. This delayed pulse is then input to a Schmidt trigger which provides a switching threshold. The output of the Schmidt trigger is utilized to inhibit the operation of a synchronous motor in the motor drive package. The missing pulse detector is operable to detect rapid increases in acceleration of the driving frequency and added or deleted pulses therein.
    Type: Grant
    Filed: January 29, 1982
    Date of Patent: April 3, 1984
    Assignee: Varo, Inc.
    Inventors: William E. Evans, Jimmie D. Gillett
  • Patent number: 4262241
    Abstract: A control system for a commutatorless motor comprises a frequency converter which includes two graetz-connected thyristor converters and D.C. lines interconnecting the converters, between an A.C. motor and an A.C. power supply. Motoring operation and regenerating operation are selectively effected between the motor and the power supply. In switching the operation mode, one of the converters which has been operated in a recitifier operation mode is first switched to an inverter operation mode, and after it has been confirmed that a control voltage to determine a firing angle of the one converter has been shifted to an inverter region, the other convertor is switched to the rectifier operation mode.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: April 14, 1981
    Assignee: Hitachi, Ltd.
    Inventor: Noboru Azusawa
  • Patent number: 4238717
    Abstract: A machine includes a rotor with a magnetic field produced therein that is fixedly oriented with respect to the rotor. The rotor is rotatably mounted within a stator which has a plurality of windings. Means are provided for applying voltage pulses to the stator windings. When voltage pulses are applied to the stator windings, there is a torque due to the interaction of a magnetic field produced in the stator windings and the rotor magnetic field that causes the rotor to rotate. A control system responds to voltage induced across unpowered stator windings by the rotating rotor magnetic field and controls application of the voltage pulses to the stator windings. The voltage pulse sequence, frequency, and duration are determined by the control system. The control system may also adjust the voltage pulse amplitude. The voltage pulses are applied to the stator windings in such a way that the machine operates at optimum efficiency and at a selectable speed over a wide range of loads and/or line voltages.
    Type: Grant
    Filed: May 23, 1977
    Date of Patent: December 9, 1980
    Assignee: Nu-Tech Industries, Inc.
    Inventors: John H. Knight, Milton S. Isaacson