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.

Abstract: Machine and method for machining large crankshafts, which allows simple and reliable synchronization of the rotation of said crankshafts (14) at all points, where said machine has a machining tool (1) configured to move along at least one guide (2) between a first end supporting element (3) and a second end supporting element (4), comprising a first electronic angular position sensor (6) situated on a first rotation shaft (7) of said first end supporting element (3), also comprising a second electronic angular position sensor (8) located on a second rotation shaft (9) of said second end supporting element (4), so that the rotational movement of said first end supporting element (3) is electronically synchronized with the rotational movement of said second end supporting element (4) at all times during the machining of the crankshaft (14).