Motor with stator cover formed by overlapping two members

摘要

A motor includes a cover made of a resin material. The cover includes a first annular portion arranged to extend in an annular shape above coils, a side wall portion arranged to extend downward from an outer circumferential portion of the first annular portion, and a second annular portion arranged to extend radially outward or radially inward from a lower end portion of the side wall portion along an upper surface of a circuit board. The side wall portion is arranged to extend in an axial direction while filling in gaps between teeth on a radially inner side of radially outer end surfaces of the teeth. The coils are covered by the cover to be protected from dust, water droplets, etc. The radially outer end surfaces of the teeth are exposed from the cover, and are thus arranged to be in radial proximity to a rotor magnet.

主权项

1. A motor comprising:
a stationary portion; and a rotating portion supported to be rotatable with respect to the stationary portion; wherein the rotating portion includes:
a shaft arranged to extend along a central axis extending in a vertical direction;a rotor holder including a cylindrical portion arranged to be coaxial or substantially coaxial with the central axis; anda rotor magnet arranged on an inner circumferential surface of the cylindrical portion; the stationary portion includes:
a plurality of teeth arranged radially inward of the rotor magnet, and arranged to extend radially with respect to the central axis;coils each of which is wound on a separate one of the teeth;a bearing portion arranged to rotatably support the shaft;a bearing support portion arranged to hold the bearing portion;a base portion arranged to extend radially outward from the bearing support portion below the coils;a circuit board arranged on an upper portion of the base portion; anda cover made of a resin material; the cover includes:
a first annular portion arranged above the coils to extend in an annular shape;a side wall portion arranged to extend axially downward from an outer circumferential portion of the first annular portion; anda second annular portion arranged to extend radially outward or radially inward from a lower end portion of the side wall portion along an upper surface of the circuit board; an inner circumferential portion of the first annular portion and one of the bearing support portion and a member directly or indirectly fixed to the bearing support portion are arranged to be in contact with each other, or in close proximity to each other with a slight gap intervening therebetween; the second annular portion and one of the base portion, the bearing support portion, and a member directly or indirectly fixed to one of the base portion and the bearing support portion are arranged to be in contact with each other, or in close proximity to each other with a slight gap intervening therebetween; the side wall portion is arranged to extend in an axial direction while filling in or substantially filling in gaps between the teeth on a radially inner side of radially outer end surfaces of the teeth; and the cover member is defined by at least a first cover member and a second cover member, the first cover member and the second cover member including radially overlapping end portions between the teeth.