Positioned In Magnetic Air Gap Patents (Class 310/49.48)
  • Patent number: 10090746
    Abstract: Step motors have a uniformed 8-stator pole design, while maintaining the number of stator teeth very close to the number of rotor teeth for better torque. A two-phase bipolar stepper includes an 8-pole stator with a plurality of stator teeth uniformly arranged on each pole. If D is the nominal inner diameter of the stator expressed in millimeters, a number of stator teeth per pole equal to D÷3 (rounded to the nearest integer) will accommodate the required winding needle space between adjacent stator poles. The step motor also has a rotor mounted for rotation within the stator with a plurality of rotor teeth. The respective numbers of rotor and stator teeth may differ at most by two or have a tooth ratio greater than 95%. The teeth should have minimum tooth width and separation of at least 0.5 mm for adequate contrasting magnetic definition (polarity and/or flux amplitude) in the rotor-stator interaction.
    Type: Grant
    Filed: January 27, 2016
    Date of Patent: October 2, 2018
    Assignee: Lin Engineering, Inc.
    Inventors: Ted T. Lin, Richard L. Badgerow
  • Patent number: 8704413
    Abstract: An electromagnetic step-by-step wobbling micromotor comprises an inner component and an annular component being external to the inner one. The outer component may be a stator and the inner component a rotor, or vice versa. The inner component has three or more poles with a winding on each pole, and an external surface facing an internal surface of the outer component. During the operation of the micromotor each winding is powered. The external and internal surfaces have toothed surfaces. Each tooth has a peak radius which is different from the valley radius.
    Type: Grant
    Filed: September 28, 2009
    Date of Patent: April 22, 2014
    Assignee: Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna
    Inventors: Cesare Stefanini, Paolo Dario, Maria Chiara Carrozza, Sarah De Cristofaro
  • Publication number: 20110210627
    Abstract: An electromagnetic step-by-step wobbling micromotor comprises an inner component and an annular component being external to the inner one. The outer component may be a stator and the inner component a rotor, or vice versa. The inner component has three or more poles with a winding on each pole, and an external surface facing an internal surface of the outer component. During the operation of the micromotor each winding is powered. The external and internal surfaces have toothed surfaces. Each tooth has a peak radius which is different from the valley radius.
    Type: Application
    Filed: September 28, 2009
    Publication date: September 1, 2011
    Inventors: Cesare Stefanini, Paolo Dario, Maria Chiara Carrozza, Sarah De Cristofaro
  • Patent number: 7847453
    Abstract: There is provided a bearingless step motor in which a rotating shaft can rotate while rising from a main body by a magnetic force without using a mechanical bearing. The bearingless step motor comprises a stator including stator cores having winding portions and a rotor including a rotating shaft and rotor cores. The rotor rotates by a magnetic interaction between the rotor cores and the stator cores. A first permanent magnet is mounted to the rotor and a second permanent magnet is mounted to the stator. The first permanent magnet and the second permanent magnet are arranged so that a repulsive force is generated between magnetic poles. There is little power consumption for raising the rotating shaft and a complicated system for controlling the rise of the rotating shaft is unnecessary. Thus, the motor can be manufactured with a light and compact structure.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: December 7, 2010
    Assignee: Korea Institute of Science and Technology
    Inventors: Seung Jong Kim, Du Jin Bach, Hosung Kong