Frame structure of motor and method for manufacturing frame and armature of motor

A frame structure of a motor, comprising:

• a frame including a polygonal outer periphery, and a circular inner periphery;
• and
• an armature core to be inserted into the inner periphery of the frame, wherein
• the armature core includes
• stacked second core sheets of an integral structure where all magnetic poles are connected in a circumferential direction of the second core sheet, or
• stacked third core sheets of a T-shape where all the magnetic poles are separated in a circumferential direction of the third core sheet, a predetermined number of the stacked third core sheets are combined at equal intervals to be assembled together in a concentric circular form having opening between distal end portions of the magnetic poles,
• the number of angles of the polygon of the outer periphery of the frame is defined on the basis of the number of peaks of the thickness of the frame in cross section as viewed in a radial direction from a rotation axis of the frame, and
• the armature core is inserted into the frame in such a manner as to form a variation θ within a predetermined range in the circumferential direction between a reference line that is orthogonal to two opposing sides of the frame and passes through the rotation axis, and a straight line linking the magnetic poles symmetric about a point with respect to the rotation axis, assuming that the number of angles of the frame is 4M where M is a natural number and M≥1, and the number of slots of the armature core is 6N where N is a natural number and N≥1.

A method for manufacturing a frame and armature of a motor, comprising forming an armature core to be inserted into an inner periphery of a frame including a polygonal outer periphery and the circular inner periphery by stacking a plurality of first core sheets on top of each other, or stacking the first core sheets and second core sheets alternately, wherein

• in the first core sheet, distal end portions of adjacent magnetic poles on a rotation axis side of the frame are coupled by bridges,
• in the second core sheet, openings are formed between the distal end portions of the adjacent magnetic poles on the rotation axis side without coupling the distal end portions,
• the method further comprises inserting the armature core into the frame by use of a position determiner in such a manner as to form a variation θ within a predetermined range in a circumferential direction between a reference line that is orthogonal to two opposing sides of the frame and passes through the rotation axis, and a straight line linking the magnetic poles symmetric about a point with respect to the rotation axis, assuming that the number of angles of the polygon of the outer periphery of the frame is 4M where M is a natural number and M≥2, and the number of slots of the armature core is 6N where N is a natural number and N≥2), and
• the number of angles of the frame is defined on the basis of the number of peaks of the thickness of the frame in cross section as viewed in a radial direction from the rotation axis of the frame.

A method for manufacturing a frame and armature of a motor, comprising:

• forming an armature core to be inserted into an inner periphery of a frame including a polygonal outer periphery and the circular inner periphery by stacking second core sheets of an integral structure where all magnetic poles are connected in a circumferential direction of the second core sheet, or stacking third core sheets of a T-shape where all the magnetic poles are separated in a circumferential direction of the third core sheet and combining a predetermined number of the stacked third core sheets at equal intervals to assemble the third core sheets together in a concentric circular form having openings between distal end portions of the magnetic poles;
• and
• inserting the armature core into the frame by use of a position determiner in such a manner as to form a variation θ within a predetermined range in the circumferential direction between a reference line that is orthogonal to two opposing sides of the frame and passes through the rotation axis, and a straight line linking the magnetic poles symmetric about a point with respect to the rotation axis, assuming that the number of angles of the polygon of the outer periphery of the frame is 4M where M is a natural number and M≥1, and the number of slots of the armature core is 6N where N is a natural number and N≥2, wherein
• the number of angles of the frame is defined on the basis of the number of peaks of the thickness of the frame in cross section as viewed in a radial direction from a rotation axis of the frame.