Abstract: A variable hydrostatic track system for vertical lathes includes a plurality of sectors arranged between the periphery and the central opening of an annular base. Each sector includes an upper housing with a hydraulic fluid outlet such that when the injected hydraulic fluid overflows from the housings, it forms a film between the rotating chuck and the sectors. The track system further includes a positioning mechanism having a plurality of hydraulic cylinders fixed on the annular base in a radial direction between the central opening and the sectors. The rod of each hydraulic cylinder is coupled to a piston and to one of the sectors. Each sector is guided in a radial guidance element such that, due to the action of the hydraulic cylinder, the sector is movable between an inner radial position and an outer radial position.

Abstract: The invention relates to a variable hydrostatic track system for vertical lathes which comprises a plurality of sectors (4) arranged between the periphery (1b) and the central opening (1a) of an annular base (1), each sector (4) comprising an upper housing (4a) with a hydraulic fluid outlet (4b) such that, when the injected hydraulic fluid overflows from the housings (4a), it forms a film between the rotating chuck (3) and the sectors (4); a positioning mechanism comprising a plurality of hydraulic cylinders (5) fixed on the annular base (1) in a radial direction between the central opening (1a) and the sectors (4), the rod of each hydraulic cylinder (5) being coupled to a piston (5j) and to one of the sectors (4); each sector (4) is guided in a radial guidance element (6) such that, due to the action of the hydraulic cylinder (5), the sector (4) is movable between an inner radial position and an outer radial position.