Article From: 10/27/2006 Production Machining
Hardinge's direct-drive, quick-change rotary systems, called Super-Precision, incorporate a direct-drive, rare-earth permanent magnet torque motor with no mechanical gearing. This frameless motor wraps around the spindle, eliminating the need for a separate motor extension resulting in a much smaller footprint. Liquid-cooling wraps around the motor stator housing to increase continuous torque output by 38 percent to 100 percent when used for rigorous duty cycles and heavy cutting, according to the company. Thermal isolation mounting arms and a cast iron base enable uniform heat dissipation, which holds the centerline of the spindle constant in the Super-Precision A2-5 spindle mount design.
The direct-drive design is said to eliminate backlash, which results in high servo stiffness and extremely rapid and accurate bidirectional response and repeatability of 0.01 arc/sec. When the command is given to stop at a certain angular location, it stops at that precise location with no overshoot and will repeat exactly.
The A2-5, 16C high-torque, direct-drive rotary system is ideal for difficult, high-precision machining or jip grinding applications requiring four or five axis interpolated machining or for parts that require extremely accurate angular positioning. The other model, the A2-4, 5C high-speed, direct-drive rotary system is designed to position extremely fast with a high degree of accuracy and without backlash.