Motor

Abstract

A motor includes a bearing portion including upper and lower bearings, a shaft rotatably supported by the bearing portion, a rotor magnet that rotates together with the shaft, an armature radially outside the rotor magnet, a casing that fixes the armature and holds the upper and lower bearings at a radial center thereof, and a cover. The armature includes a stator core including magnetic pole teeth, an insulator that covers at least upper and lower surface of each of the magnetic pole teeth, and coils. The casing includes a hole passing through an axial end surface of the casing in the axial direction, and the cover is opposite the hole between the casing and the armature.

What is claimed is: 
     
         1 . A motor comprising:
 a bearing portion including an upper bearing and a lower bearing;   a shaft including a central axis extending in a vertical direction as a center thereof, and rotatably supported by the bearing portion;   a rotor magnet that rotates together with the shaft;   an armature located radially outside the rotor magnet;   a casing that fixes the armature and holds the upper and lower bearings at a radial center thereof, the upper and lower bearings rotatably supporting the shaft; and   a cover; wherein   the armature includes:
 a stator core including an annular core back and a plurality of magnetic pole teeth that project radially inward from the core back; 
 an insulator that covers at least an upper surface and a lower surface of each of the plurality of magnetic pole teeth of the stator core; and 
 coils each defined by a conducting wire wound around a separate one of the plurality of magnetic pole teeth with the insulator intervening therebetween; wherein 
   the casing includes a through hole passing through an axial end surface of the casing in an axial direction; and   the cover is opposite to the through hole between the casing and the armature.   
     
     
         2 . The motor according to  claim 1 , wherein
 an upper surface of the cover is in contact with the coils; and   the cover is made of an elastic material.   
     
     
         3 . The motor according to  claim 1 , wherein
 the casing includes an upper bracket that holds the upper bearing, and a lower bracket that holds the lower bearing; wherein   the lower bracket includes:
 a lower cover portion with an annular or substantially annular plate shape; and 
 a lower projecting portion that projects axially upward from a radially outer end of the lower cover portion, and is cylindrical or substantially cylindrical. 
   
     
     
         4 . The motor according to  claim 3 , wherein an outer circumferential surface of the cover is fixed to an inner circumferential surface of the lower projecting portion. 
     
     
         5 . The motor according to  claim 3 , wherein the cover includes:
 a collar that extends axially downward radially inside the through hole;   an increased thickness portion with an increased axial thickness and located radially outside the through hole; and   a hem with a smaller axial thickness than an axial thickness of the increased thickness portion and located radially outward of the increased thickness portion; wherein   the collar is in contact with the lower cover portion.   
     
     
         6 . The motor according to  claim 5 , wherein a portion of an inner circumferential surface of the collar includes an inclined portion extending radially inward with decreasing height. 
     
     
         7 . The motor according to  claim 4 , wherein the cover is inside the inner circumferential surface of the lower projecting portion and the hem is adjacent to the inner circumferential surface of the lower projecting portion. 
     
     
         8 . The motor according to  claim 1 , wherein an inner circumferential surface of the through hole includes a screw groove.