上充通大学 Shanghai Jiao Tong University Flexible Transmission Elements2 Belt Drives >Used where rotational speeds are relatively high >Linear speed of belt about 2,500 to 7,000 ft/min Ideal around 4,000 ft/min. >At lower speeds, Tension in the belt becomes too large for typical belt cross sections >At higher speeds, √Dynamic effects such as centrifugal forces(离心力)， belt whip,vibration reduce effectiveness of drive and its life. 77 Flexible Transmission Elements2 •Belt Drives Used where rotational speeds are relatively high Linear speed of belt about 2,500 to 7,000 ft/min Ideal around 4,000 ft/min. At lower speeds, Tension in the belt becomes too large for typical belt cross sections At higher speeds, Dynamic effects such as centrifugal forces(离心力), belt whip, vibration reduce effectiveness of drive and its life