Motor
First Claim
1. A motor comprising:
- a stator portion including an armature;
a rotor portion including a shaft concentric with a central axis, a rotor core having a substantially cylindrical shape arranged to surround the shaft, and a field magnet which is arranged at the rotor core and which, along with the armature, generates a torque centered about the central axis;
a first bearing portion and a second bearing portion arranged at a corresponding axial side of the rotor core to rotatably support the shaft;
a sensor, including a sensor magnet having a substantially annular plate shape and a first Hall element, arranged at an axial side of the armature to magnetically detect an angular position of the rotor core with respect to the stator portion;
a housing arranged to accommodate therein the stator portion and the rotor portion; and
a busbar unit arranged at an axial end of the armature to connect the armature to an external power source;
whereinthe busbar unit includes a busbar holder having a substantially annular shape or arc shape and made of an insulating material centered about the central axis;
the housing includes;
a housing body having an opening at an axial side thereof; and
a lid portion arranged between the armature and the sensor to retain the first bearing portion and to close the opening of the housing body;
the lid portion includes a first concave portion and a second concave portion arranged on an upper surface of the lid portion;
the first concave portion is arranged to accommodate the sensor magnet and the first Hall element therein;
the sensor magnet is affixed to the shaft such that the sensor magnet is arranged substantially perpendicular to the central axis to overlap the busbar holder in a radial direction;
the first Hall element is arranged to oppose a magnetized surface of the sensor magnet;
the second concave portion is arranged to accommodate the first bearing portion; and
the first concave portion and the second concave portion are arranged substantially inward of the busbar holder in the radial direction such that a circumferential surface the busbar holder is arranged to oppose the first concave portion and the second concave portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A motor includes a housing having a substantially cylindrical shape accommodating therein a stator portion and a rotor portion. The housing includes a housing body having an opening at an upper side thereof, and a lid portion arranged between an armature and a sensor so as to close the opening of the housing body. Since the lid portion is made of a magnetic material and is arranged between the armature and the sensor, a magnetic effect on the sensor caused by a magnetic force generated at the armature is minimized. By virtue of such configuration in which the lid portion of the housing functions as a magnetic shield, the motor can be smaller in the axial direction compared with a configuration in which an extra layer of magnetic shield is arranged.
22 Citations
6 Claims
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1. A motor comprising:
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a stator portion including an armature; a rotor portion including a shaft concentric with a central axis, a rotor core having a substantially cylindrical shape arranged to surround the shaft, and a field magnet which is arranged at the rotor core and which, along with the armature, generates a torque centered about the central axis; a first bearing portion and a second bearing portion arranged at a corresponding axial side of the rotor core to rotatably support the shaft; a sensor, including a sensor magnet having a substantially annular plate shape and a first Hall element, arranged at an axial side of the armature to magnetically detect an angular position of the rotor core with respect to the stator portion; a housing arranged to accommodate therein the stator portion and the rotor portion; and a busbar unit arranged at an axial end of the armature to connect the armature to an external power source;
whereinthe busbar unit includes a busbar holder having a substantially annular shape or arc shape and made of an insulating material centered about the central axis; the housing includes; a housing body having an opening at an axial side thereof; and a lid portion arranged between the armature and the sensor to retain the first bearing portion and to close the opening of the housing body; the lid portion includes a first concave portion and a second concave portion arranged on an upper surface of the lid portion; the first concave portion is arranged to accommodate the sensor magnet and the first Hall element therein; the sensor magnet is affixed to the shaft such that the sensor magnet is arranged substantially perpendicular to the central axis to overlap the busbar holder in a radial direction; the first Hall element is arranged to oppose a magnetized surface of the sensor magnet; the second concave portion is arranged to accommodate the first bearing portion; and the first concave portion and the second concave portion are arranged substantially inward of the busbar holder in the radial direction such that a circumferential surface the busbar holder is arranged to oppose the first concave portion and the second concave portion. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification