Multiphase DC motor and starting method thereof
AssigneeNippon Corporation
InventorsShiming Tang, Isao Kaneda, Hisashi Yamamoto
Life of this patent
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Abstract
A starting method for starting a multiphase DC motor having a stator provided with stator coils, a rotor provided with a rotor magnet and detector for detecting revolutions of the rotor, has stepping process and acceleration process. In the stepping process, a plurality of stepping steps is performed. The accelerating process is performed after the stepping process is completed. The plurality of the stepping steps include counter-exciting operation. Each of the plurality of stepping steps is provided by a rotation detection step. The stepping process is completed and the accelerating process is performed when a rotation detector detects that the revolutions of the rotor exceeds a predetermined value.
Claims28
A starting method for a multi-phase direct current motor having a stator provided with stator coils to which exciting currents are supplied, a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction with the stator, and rotation detecting means for detecting the rotation of the rotor, the starting method comprising:
- a plurality of stepping steps of supplying the exciting currents to the stator coils to start the multi-phase direct current motor, each of the stepping steps including a step for performing a counter-exciting operation in which directions of the exciting currents flowing through the coils are reversed without a substantial rest time;
- rotation detection steps of detecting a rotation of the rotor by means of the rotation detecting means, each of the rotation detection steps being provided following to respective one of the plurality of stepping steps;
- and
- step of, when the rotation detecting means detects in the rotation detection steps that the number of revolutions of the rotor does not reach a predetermined value, performing next stepping step, and of, when the rotation detecting means detects that the number of revolutions of the rotor exceeds the predetermined value, completing the stepping process and performing an accelerating step of accelerating the rotor.
A starting method for a multi-phase direct current motor having a stator provided with stator coils to which exciting currents are supplied, and a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction;
- the starting method including stepping, transfer and accelerating steps both performed in a starting operation;
- the stepping step including a step of performing a counter-exciting operation in which the exciting currents are reversed without including a substantial rest time, the counter-exciting operation being sequentially performed in each phase of the stator coils such that a frequency of the exciting currents to be supplied to the stator coils is approximately identical with a natural oscillation frequency of the motor in the transfer step.
A multiphase direct current motor, comprising:
- a stator provided with stator coils to which exciting currents are supplied;
- a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction with the stator;
- bearing means inserted between the stator and the rotor;
- revolution detecting means for detecting the number of revolutions of the motor;
- control means for controlling the rotation of the rotor by supplying the exciting currents to the stator coils to perform a stepping process and an accelerating process in a starting operation;
- a sequencer for generating predetermined internal stepping pattern signals;
- and
- driver means for supplying the exciting currents to the stator coils in accordance with the internal stepping pattern signals from the sequencer, during the stepping process the control means controlling the sequencer to supply to the driver means the exciting stepping pattern signals skipped every other signal or every two signals in a forward or backward direction from the internal stepping pattern signals, and the driver means supplying the exciting currents to each phase of the stator coils so as to perform a counter-exciting operation in which the exciting currents are reversed without including a substantial rest time.
A starting method for a multi-phase direct current motor having a stator provided with stator coils to which exciting currents are supplied, and a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction,
- the starting method including stepping and accelerating steps both performed in a starting operation,
- the stepping step including a step of performing a counter-exciting operation in which the exciting currents are reversed without including a substantial rest time, the counter-exciting operation is sequentially performed in each phase of the stator coils, a supplement time of the exciting currents is supplied to the stator coils and is gradually increased as the step advances, and a frequency of the exciting currents varies from a first value larger than a natural oscillation frequency of the motor to a second value smaller than the natural oscillation frequency as the step advances.
A starting method for a multi-phase direct current motor having a stator provided with stator coils to which exciting currents are supplied, and a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction,
- the starting method including stepping and accelerating steps both performed in a starting operation,
- the stepping step including a step of performing a counter-exciting operation in which the exciting currents are reversed without including a substantial rest time, the counter-exciting operation being sequentially performed in each phase of the stator coils,
- wherein the motor includes:
- a sequencer for generating predetermined internal stepping pattern signals;
- driver means for supplying the exciting currents to the stator coils in accordance with the internal stepping pattern signals from the sequencer;
- and
- control means for controlling the internal stepping pattern signals supplied from the sequencer to the driver means;
- and wherein the control means controls the sequencer to supply the driver means with exciting stepping pattern signals skipped every other signal or every two signals in a forward or backward direction from the internal stepping pattern signals, whereby the counter-exciting operation is performed.
A starting method for a multi-phase direct current motor having a stator provided with stator coils to which exciting currents are supplied, and a rotor provided with a rotor magnet acquiring a rotation torque by electromagnetic interaction,
- the starting method including stepping and accelerating steps both performed in a starting operation,
- the stepping step including a step of performing a counter-exciting operation in which the exciting currents are reversed without including a substantial rest time, the counter-exciting operation being sequentially performed in each phase of the stator coils,
- wherein the stator coils are activated by the counter-exciting operation during the accelerating step, and further comprising:
- a sequencer for generating predetermined internal drive pattern signals;
- driver means for supplying the exciting currents to the stator coils in accordance with the internal drive pattern signals;
- and
- control means for controlling the internal drive pattern signals supplied from the sequencer to the driver means;
- and wherein the control means controls the sequencer to supply the driver means with exciting drive pattern signals skipped every other signal or every two signals in a forward or backward direction from the internal driver pattern signals, whereby the counter-exciting operation is performed in the accelerating process.
Dependencies are inferred from the claim text.