Vertical lathe with machining centre performance

The Okuma VTM-80YB vertical lathe is aimed users wanting to process parts weighing up to 1.5 tonnes in single set-up. The 23 tonne machine has been designed as a cross between a heavy duty vertical turning and boring facility and a 5-axis machining centre capable of simultaneously interpolating up to four CNC axes. Structurally it is configured as a bed-type machining centre but instead of a conventional table it has a 30 kW turning spindle/table driven via a two-speed gearbox. This offers steplessly variable speeds in the range 4-270 rpm (low range) and 8-800 rpm (high range). In addition it provides 360,000-increment C-axis positioning. Two large-cross-section, X-axis slideways carry a substantial column with vertical Z-axis slides. These in turn locate a saddle with Y-axis cross slides to support the 18.5 kW/4,000 rpm motor-spindle (B-axis). By locking the motor spindle using a Curvic coupling,it becomes possible to use it for turning operations without risk of damage to the bearings. The B-axis can position the spindle between vertical and horizontal machining positions in 5° increments.