a metal-cutting lathe designed for large articles with relatively small length / in comparison to diameter D(l/D < 1 for light and medium lathes, l/D < 0.5 for heavy lathes).
The vertical lathe makes it convenient to mount, align, and fasten the items to be worked. For this reason it has replaced the facing lathe, which was used previously. The distinguishing feature of the vertical turning lathe is the vertical position of the spindle. A chuck is located on the top of the spindle; the piece to be worked is fastened to the chuck, using radially displaced cams. It is the item itself that goes through the principal rotary motion on the vertical lathe; the cutting tool, fixed on a support, has a translatory feed motion. The strain on the spindle is partially relieved because the weight of the item and the cutting forces are absorbed by the circularly directing chucks.
There are open-sided and double-sided (portal) vertical lathes. Open-sided vertical lathes usually have both vertical and lateral supports; two-sided lathes have two vertical and either one or two lateral supports. A rotating turret is often placed on one of the vertical supports. The vertical lathe is usually driven by several electric motors (many, in the case of the heavy lathe), which, during operation, transmit the motion to the chuck spindle and supports (working and idling or accelerated) and serve to attach the crosshead and brake engagement.
The vertical lathe is used to machine and bore cylindrical, conical, and contoured surfaces and to trim face ends. Lathes with a turret can also drill, counterbore, and ream. Engraving, slotting, milling, and polishing are possible with special attachments. It is possible on a vertical lathe to work with a number of cutting tools simultaneously, with each tool fastened to a separate support. This increases efficiency significantly.
The rigidity of construction of the vertical lathe makes it possible to work on particularly large items with a high degree of precision. For example, pieces weighing as much as 500 tons and more, with diameters to 30 m (parts of powerful hydraulic turbines, turbogenerators, atomic reactors, and proton synchrotrons), may be worked on heavy two-sided models.
D. L. YUDIN