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US 5,982,064 AGranted
DC motor
AssigneeNidec Corporation
InventorsFumihiro Umeda, Shuji Takahashi
Life of this patent
Estimating the term…
Abstract
The DC motor according to the present invention includes one radial ball bearing and a thrust bearing constituted by a shaft receiving member provided on a housing to be abutted by one end of a rotating shaft. Further, a magnetic and/or a spring bias force is applied to the rotating shaft to supplement thrust load bearing force of the thrust bearing. Compared with conventional DC motors in which a rotor is supported by a shaft through a pair of ball bearings which are axially spaced apart from each other, the present invention enables reduction of the overall motor height without harming the rotational stability while simultaneously achieving low production cost.
Claims36
A DC motor comprising:
- a stationary member;
- a shaft rotatable relative to the stationary member;
- a rotor fixed on one end of the shaft;
- a base plate having a sleeve member for rotatably supporting the shaft;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator,
- a shaft receiving member fixedly mounted on the stationary member at a position to oppose one end of the shaft and having a curved concave portion against which the one end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
8 more elements
A DC motor comprising:
- a housing;
- a sleeve member connected to the housing;
- a shaft rotatably supported by the sleeve member;
- a rotor fixed on one end of the shaft;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the sleeve member;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member provided on the housing at a position to oppose a free end of the shaft and having a curved concave portion against which the free end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
8 more elements
A fan motor comprising:
- a housing having an air passage way;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member;
- a rotor fixed on one end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the housing at a position to oppose one end of the shaft and having a curved concave portion against which the one end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
8 more elements
A fan motor comprising:
- a housing having an air passage way;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member;
- a rotor fixed on one end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the base plate at a position to oppose a free end of the shaft and having a curved concave portion against which the free end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
8 more elements
A heat sink fan comprising:
- a heat sink having a base member and a plurality of radiating fins formed on the base member;
- a housing attached to the heat sink and having an air passage;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member;
- a rotor fixed on one end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the housing at a position to oppose to one end of the shaft and having a curved concave portion against which the one end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
9 more elements
A heat sink fan comprising:
- a heat sink having a base member and a plurality of radiating fins formed on the base member;
- a housing attached to the heat sink and having an air passage;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member;
- a rotor fixed on one end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the heat sink at a position to oppose to a free end of the shaft and having a curved concave portion against which the free end of the shaft abuts;
- and
- biasing means for urging the shaft toward the shaft receiving member.
9 more elements
A DC motor comprising:
- a stationary member;
- a shaft rotatable relative to the stationary member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft;
- a base plate having a sleeve member for rotatably supporting the shaft;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including, an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being;
- fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the stationary member at a position to oppose the one end of the shaft and having a curved concave configuration with a radius of curvature R2 which is larger than the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact with each other by pin point contact;
- and
- biasing means for urging the shaft toward the shaft receiving member.
9 more elements
A DC motor comprising:
- a housing;
- a sleeve member connected to the housing;
- a shaft rotatably supported by the sleeve member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the sleeve member;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member provided on the housing at a position to oppose the hemispherical end of the shaft and having a curved concave configuration with the radius of curvature R2 which is larger than the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact with each other by pin point contact;
- and
- biasing means for urging the shaft toward the shaft receiving member.
8 more elements
A fan motor comprising:
- a housing having an air passage way;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the housing at a position to oppose the hemispherical end of the shaft and having a curved concave configuration with a radius of curvature R2 which is larger than the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact with each other by pin point contact;
- and
- urging means for urging the shaft toward the shaft receiving member.
8 more elements
A fan motor comprising:
- a housing having an air passage way;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the base plate at a position to oppose the hemispherical end of the shaft and having a curved concave configuration with a radius of curvature R2 which is larger than the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact within each other by pin point contact;
- and
- urging means for urging the shaft towards the shaft receiving member.
8 more elements
A heat sink fan comprising:
- a heat sink having a base member and a plurality of radiating fins formed on the base member;
- a housing attached to the heat sink and having an air passage;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the housing at a position to oppose the hemispherical end of the shaft and having a curved concave configuration with a radius of curvature R2 which is larger that the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact with each other by pin point contact;
- and
- urging means for urging the shaft towards the shaft receiving member.
9 more elements
A heat sink fan comprising:
- a heat sink having a base member and a plurality of radiating fins formed on the base member;
- a housing attached to the heat sink and having an air passage;
- a supporting plate having a sleeve member and connected to the housing through a plurality of webs;
- a shaft rotatably supported by the sleeve member and the one end of the shaft having a hemispherical configuration with a radius of curvature R1;
- a rotor fixed on the other end of the shaft and having a plurality of fan blades;
- a retaining portion formed in the inner circumferential surface of the sleeve member;
- a ball bearing including an inner race and an outer race and a plurality of balls disposed therebetween, and interposed between the shaft and the sleeve member, the outer race being fixed to the sleeve member so as to be in contact with the inner circumferential surface of the sleeve member and the retaining portion and the inner race holding the shaft;
- a stator attached to the base plate;
- a rotor magnet secured to the rotor so as to oppose the stator;
- a shaft receiving member fixedly mounted on the heat sink at a position to oppose the hemispherical end of the shaft and having a curved concave configuration with a radius of curvature R2, which is larger that the radius of curvature R1, the hemispherical end of the shaft and the curved concave portion being in contact with each other by pin point contact;
- and
- urging means for urging the shaft towards the shaft receiving member.
9 more elements
Dependencies are inferred from the claim text.