| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the hooking of a turntable to the difference in level, etc., of a center hole by forming a tapered part of the turntable with the angle so as not to bring the turntable into contact with the edge of center hole and positioning at the center hole lower than the combined surface. SOLUTION: The combined disk 11 is normally bonded in the deviated state within the specification of disk and required to place it on the turntable 10. The tapered part 15 is formed with the angle, so as not to make contact with the edge of center hole 6. An apex angle of the tapered part 15 is set in the range, satisfying the inequalities tanθ>d1/(m1-m2), tanθ>=2 (n1-n2)/n3}, tanθ<1/μ. In these equations, θ is 1/2 of the apex angle 2θ of tapered part, m1 is the distance from the disk-placing surface 16 to the upper surface of tapered part 15, m2 is the distance from the disk-placing surface 16 to the upper end of a fitted part 5, n1 is the level difference for the clad disk 11, n2 is the clearance between the disk 11 and the fitted part 5, n3 is the difference in level of the taper, and μ is the coefficient of friction between the clad disk 11 and the tapered part 15. |
