1089 Каталог WIDIA 2011 Инструментальная оснастка для металлорежущих станков Стр.K53

Каталог WIDIA 2011 Инструментальная оснастка Стр. K53 1089 ENG Lab2u

WIDIA Technical Information Balancing Balancing The balance quality is usually specified by the balance grade G, according to ISO 1940-1 and ANSI S2.19 standards. The balance quality grade (G) was derived from practical experience, which is expressed in millimeters per second (mm/s) and ranges from 0,16-4000. For rotating tooling and general machinery parts, it is usually specified to be G 2.5 or G 6.3. A lower number designates better balance quality. The permissible residual unbalance can be calculated by the following equation: 9549 x G x M U per = n Where: Example: U per = permissible unbalance, expressed in gram millimeters (gmm) Rotor mass = 2 kg G = desired balance grade n = 10,000 RPM M = rotor mass in kilograms (kg) Desired balancing grade = G 6.3 n = operating speed in rotations per minute (RPM) ii = 9549 x 6.3 x 2 12 gmm U 10,000 = 12 gmm The same value can be obtained from the chart on the following page. It gives the permissible specific unbalance in gram millimeters (gmm) as a function of the rotational speed and the balance quality (G). For the example above, at 10,000 RPM and for grade G 6.3, the maximum residual unbalance would be 6 gmm/kg. The toolholder assembly (including the tool) has a mass equal to 2 kg, the permissible unbalance is (6 gmm/kg) x 2 kg , which equals 12 gmm. (continued) WIDIA K53 Technical Information