You Ji VTH Series (Vertical Turning Lathes with Hydrostatic Bearing) up to 8 Meters
You Ji VTH vertical turning lathes are engineered for heavy duty turning of large workpieces. The series is comprised of 32 machines with standard cutting diameters ranging from 130″ to 350″ (3300 mm to 8900 mm), and spindle power extending from 100 hp to 133 hp.
The heavy-duty spindle incorporates a high precision hydrostatic bearing designed to withstand high axial and radial loads. In the hydrostatic system, pockets of oil between the base of the machine and the table eliminate contact between mating surfaces and promote friction-free operation. A dual-wound 133 hp Fanuc high-torque spindle motor is coupled with a 2-speed ZF helical planetary gearbox. The combination of the high/low motor and 2 speed gearbox provides the benefits of a 3-speed transmission. Power is transmitted through a Class 1 ring and pinion gear that provides a further gear reduction and torque multiplication. This massive spindle can support a table load of up to 650,000 lbs. With the C-axis option, dual 100hp tandem spindle motors allow 10 arc second positioning and 5 arc seconds repeatability.
The X and Z axes are a box way design that facilitates heavy duty machining and high precision. The Turcite B-coated ways are completely enclosed and feature a forced lubrication system. The rigid twin column design and heavy base are Meehanite castings, heavily ribbed to minimize thermal distortion and dampen vibration.
The Z-axis is a large cast-steel square ram that is extremely rigid even when extended to its full length of 59″ (1500 mm), opt. 78.7″ (2000 mm). A 15.7″ x 15.7″ [400 mm x 400 mm] ram with BT-60 tool interface is optional for extra-heavy-duty cutting. Precision Class 3 ballscrews are driven directly by servo motors, eliminating belts or gears. The cross rail moves on box ways in 200mm increments and automatically latches against fixed stops. It is positioned by dual lead screws on each side of the column and is hydraulically clamped for rigidity.
