Direct current brushless motor for a fan
OwnerHsin-Mao Hsiehinventor
Life of this patent
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Abstract
The invention discloses a direct current brushless motor for a fan. The motor has a housing, a stator, and a rotor. The stator has four pole sheets, a sensor installed between two neighboring pole sheets, and a circuit board electronically connected to the sensor. The rotor is installed on a shaft and has a metal cover under the housing and four permanent magnets. The sensor has a sensing window used to sense the magnetic strength of the permanent magnets. The sensor and the sensing window accordingly are offset a certain distance from a point directly above where two neighboring permanent magnets meet to obtain a better activation effect.
Claims10
A direct current brushless motor for a fan, with the motor having a housing, a stator, and a rotor, with the stator having four stator poles, with a gap being defined between neighboring stator poles, a sensor installed between two neighboring stator poles and a circuit board electronically connected with the sensor, with the rotor being installed on a shaft and having a metal cover under the housing and having four permanent magnets, with the sensor having a sensing window used for sensing magnetic strength of the permanent magnets, with the improvements comprising:
- the sensing window of the sensor altered an offset distance from a position midway in the gap defined between the two neighboring stator poles, poles, wherein the sensing window offset distance is from a point where the magnetic strength of the permanent magnets sensed by the sensor crosses a sensibility line of the sensor to a nearest zero point.
A direct current brushless motor for a fan, with the motor having a housing, a stator, and a rotor, with the stator having eight stator poles, with a gap being defined between neighboring stator poles, a sensor installed between two neighboring stator poles and a circuit board electronically connected to the sensor, with the rotor being installed on a shaft and having a metal cover under the housing and having eight permanent magnets, with the sensor having a sensing window used for sensing magnetic strength of the permanent magnets, wherein the improvements comprise:
- the sensing window of the sensor offset an offset distance from a position midway in the gap defined between the two neighboring stator plates, plates, wherein the offset distance is from a point where the magnetic strength of the permanent magnets sensed by the sensor crosses a sensibility line of the sensor to a nearest zero point.
Dependencies are inferred from the claim text.