CNC carving and milling machine tool selection of ball screw

First, CNC carving and milling machine screw the lead should be selected according to the highest speed feed Vmax highest speed Nmax, servo motor, motor and ball screw transmission ratio (I) to determine, screw lead should satisfy: P not less than Vmax/( 我! Nmax) , feed a maximum speed of 3000 mm/min, the stepper motor a maximum speed of 1000 r/min, so screw lead 3 mm. Second, CNC carving and milling machine precision of ball screw directly affect the positioning accuracy of CNC carving and milling machine tool, the precision of ball screw parameters, the lead error had evident effects on the CNC carving and milling machine tool positioning accuracy. When the design, set screw any 300 mm trip changes the amount shall be the design positioning accuracy value of 0. 3 to 0. 5 times, the last check. Again, was obtained by dynamic load rating for the numerical control carving and milling machine tool ball screw pair of ball screw specifications, in practice the rated dynamic load value can press type calculation, C = fh! fd ! 跳频! Pd/fn, among them, the fh as life factor, according to the numerical control carving and milling machine tool ball screw life expectancy to choose; Fd for the nature of the load coefficient, according to the nature of the work load selection; Fh for dynamic load hardness influence coefficient, according to the ball and the raceway surface hardness selection; Fn for speed coefficient, average speed nd selection by the screw; Pd for average axial load. In practice, engraving and milling machine > working conditions and the working time and irregular, average axial load and the average speed can be calculated by the following formula: Pd = ( 2 pmax + Pmin) /3,nd=( 2nmax+nmin) / 3 minimum axial load of the workbench and the workpiece under the action of guide rail friction, the calculation of the maximum axial load is the maximum load borne by the machine when the ball screw pair of momentum, it for cutting force in the axial component of the ball screw and guide rail friction is combined. Finally find manufacturers to provide product data sheet, choose lead to 4 mm, 16 mm diameter, end flange nuts, nut for preload C5 level precision of the leadscrew vice, positioning accuracy is 0. 018毫米。 Screw pair determine again after to check its stability, the critical speed and rigidity. How much a ningbo engraving machine? Consult ningbo sea yifan, CNC engraving machine co. , LTD.