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US 7,067,998 B2Granted
Drive circuit for brushless DC motors
AssigneePapst Licensing GmbH & Co. KG
InventorsArno Karwath, Mojtaba Moi, Eberhard Wünsch
Life of this patent
Estimating the term…
Abstract
A drive circuit for brushless DC motors including a rotor and a stator with at least one stator coil includes a commutation device which supplies commutation pulses of drive current to the stator coil(s). The commutation device senses the rotor position and calculates current rotor speed therefrom. The rotor speed is then used to shift the commutation circuits according to predetermined functions. The shifting of commutation currents is occasioned by shifting either or both of the ignition part of a commutation pulse and the extinction part of such pulse.
Claims27
An assembly comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and
- a drive circuit comprising:
- a rotor position measurement circuit for measuring angular position of the rotor relative to the stator and for determining motor speed:
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed and wherein the commutation shifting apparatus pre-displaces the moments of commutation increasingly toward the rotational position of the rotor after a specified motor speed has been exceeded.
8 more elements
An assembly, comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and a drive circuit comprising:
- a rotor position measuring circuit for measuring angular position of the rotor relative to the stator and for determining motor speed;
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed, wherein the moments of commutation are shifted as a function of the motor speed according to an unsteady function and wherein the commutation shifting apparatus pre-displaces the moments of commutation increasingly toward the rotational position of the rotor after a specified motor speed has been exceeded.
7 more elements
An assembly comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and
- a drive circuit comprising:
- a rotor position measuring circuit for measuring angular position of the rotor relative to the stator and for determining motor speed;
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed, wherein the moments of commutation are shifted as a function of the motor speed according to a piece-wise linear function and wherein the commutation shifting apparatus pre-displaces the moments of commutation increasingly toward the rotational position of the rotor after a specified motor speed has been exceeded.
8 more elements
An assembly comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and
- a drive circuit comprising:
- a rotor position measurement circuit for measuring angular position of the rotor relative to the stator and for determining motor speed:
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed and wherein the commutation shifting apparatus, responsive to initial start-up, pre-displaces the moments of commutation by a specified, first electrical preignition angle with respect to the rotational position of the rotor.
8 more elements
An assembly, comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and
- a drive circuit comprising:
- a rotor position measuring circuit for measuring angular position of the rotor relative to the stator and for determining motor speed;
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed, wherein the moments of commutation are shifted as a function of the motor speed according to an unsteady function and wherein the commutation shifting apparatus, responsive to initial start-up, pre-displaces the moments of commutation by a specified, first electrical preignition angle with respect to the rotational position of the rotor.
8 more elements
An assembly comprising:
- a load member;
- and
- a brushless DC motor, comprising:
- a rotor;
- a stator housing at least one stator coil;
- and
- a drive circuit comprising:
- a rotor position measuring circuit for measuring angular position of the rotor relative to the stator and for determining motor speed;
- a commutator circuit for connecting and interrupting current to the stator coil at specified moments of commutation determined from the angular rotor position relative to the stator;
- and
- a commutation shifting apparatus for shifting the specified moments of commutation, the amount of shifting being a predetermined function of motor speed, wherein the moments of commutation are shifted as a function of the motor speed according to a piece-wise linear function and wherein the commutation shifting apparatus, responsive to initial start-up, pre-displaces the moments of commutation by a specified, first electrical preignition angle with respect to the rotational position of the rotor.
8 more elements
Dependencies are inferred from the claim text.