Brushless motor and magnetic recording-reproducing apparatus using the same

Claim 2

A brushless motor comprising: a stator including a plurality of substrates protruding radially with respect to a center axis of the stator, and a plurality of coils, each coil being wound on each of said substrates; a rotor including a cover having a plurality of annularly arranged magnetic poles, for covering said stator, wherein said magnetic poles are disposed opposing tip-end faces of said substrates; and a plurality of first apertures provided in an upper wall of said cover, wherein said magnetic poles provided inside the upper wall of said cover and the tip-end faces of said substrates are visible from the outside of the upper wall through said first apertures.

Claim 3

A brushless motor according to claim 1, further comprising: a stator retained by a reinforcing plate of a magnetic material, said reinforcing plate including a plurality of second apertures, wherein said magnetic poles are visible from the outside of a bottom surface of said reinforcing plate through said second apertures.

Claim 4

A brushless motor according to claim 1, wherein said first apertures in the upper wall of said cover are sealed with a nonmagnetic sealing material.

Claim 5

A brushless motor according to claim 1, wherein the following condition is met: (Z1+Z2+ . . . )=N×P×A, wherein A represents an integer of 1 or greater, N represents the number of phases forming a current for said brushless motor, P represents an angular pitch between each of said substrates, C represents the number of said substrates, C and P satisfy C×P=360 degrees, and (Z1+Z2+ . . . ) represents the sum of angular distances (Z1 degrees, Z2 degrees, . . . ) between both ends of each of said first apertures in the upper wall of said cover.

Claim 6

A magnetic recording-reproducing apparatus including a brushless motor, wherein said brushless motor comprises: a stator including a plurality of substrates protruding radially with respect to a center axis of the stator, and a plurality of coils, each coil being wound on each of said substrates; a rotor including a cover having a plurality of annularly arranged magnetic poles, for covering said stator, wherein said magnetic poles are disposed opposing tip-end faces of said substrates; and a plurality of first apertures provided in an upper wall of said cover, wherein said magnetic poles provided inside the upper wall of said cover and the tip-end faces of said substrates are visible from the outside of the upper wall through said first apertures.

Claim 7

A magnetic recording-reproducing apparatus including a brushless motor, wherein said brushless motor comprises: a stator including a plurality of substrates protruding radially with respect to a center axis of the stator, and a plurality of coils, each coil being wound on each of said substrates; a rotor including a cover having a plurality of annularly arranged magnetic poles, for covering said stator, wherein said magnetic poles are disposed opposing tip-end faces of said substrates; and a plurality of first apertures provided in an upper wall of said cover, wherein said magnetic poles provided inside the upper wall of said cover and the tip-end faces of said substrates are visible from the outside of the upper wall through said first apertures.

Claim 8

A magnetic recording-reproducing apparatus including a brushless motor, according to claim 5, wherein said brushless motor further comprises: a stator retained by a reinforcing plate of a magnetic material, said reinforcing plate including a plurality of second apertures, wherein said magnetic poles are visible from the outside of a bottom surface of said reinforcing plate through said second apertures.

Claim 9

A magnetic recording-reproducing apparatus including a brushless motor, according to claim 5, wherein said first apertures in the upper wall of said cover are sealed with a nonmagnetic sealing material.

Claim 10

A magnetic recording-reproducing apparatus including a brushless motor, according to claim 5, wherein the following condition is met: (Z1+Z2+ . . . )=N×P×A, wherein A represents an integer of 1 or greater, N represents the number of phases forming a current for said brushless motor, P represents an angular pitch between each of said substrates, C represents the number of said substrates, C and P satisfy C×P=360 degrees, and (Z1+Z2+ . . . ) represents the sum of angular distances (Z1 degrees, Z2 degrees, . . . ) between both ends of each of said first apertures in the upper wall of said cover.