| 摘要 |
PROBLEM TO BE SOLVED: To simply and minutely perform an adjustment work of an inertia moment within a wide adjustment range without deteriorating a center-of-gravity position in a whole system.SOLUTION: A balance 10 includes: a balance staff 11 pivotally supported so as to be rotatable; a rim part 20 surrounding the balance staff from the outside in a radial direction and coaxially placed with a rotational axis O; and a balance wheel 12 having connection arms 21 that connect the rim part to the balance staff in the radial direction. The rim part is divided in a circumferential direction and includes multiple divided rim parts 22 and 23 that are extended in the circumferential direction and equally arranged around the rotational axis. In the divided rim parts, one end parts in the circumferential direction are defined as fixed ends 22a and 23a that are connected to the connection arms and the other end parts in the circumferential direction are defined as free ends 22b and 23b. The divided rim parts include position adjustment mechanisms 30 for elastically deforming the divided rim parts so as to move the free ends of the divided rim parts in the radial direction and adjusting the positions of the free ends. |
