Каталог Widia инструментальная оснастка - страница 1089

• WID_TOOLINGSYSTEMS10_G004_G005.qxp.pdf
• WID_TOOLINGSYSTEMS10_G006_G007.qxp
• WID_TOOLINGSYSTEMS10_G008_G009.qxp
• WID_TOOLINGSYSTEMS10_G010_G011.qxp

Technical Information Balancing Balancing The balance quality is usually specified by the balance grade G, according to IS0 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: U per = 9549 x G x Mn 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) U per = 9549 x 6.3 x 210,000= 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) WWW.WIDIA.COM K53 Technical Information