XL CATALOG

Essential drive design starting data is: · Mass M to be moved with the drive, ‘table+part’ · The travel l r or distance the table is moved · Feed speed v · Acceleration a · Duty cycle First of all, It is necessary to select the family of the ball screw: · With Preload: Positioning ball screws, Technologies COMPLEX or PRIME Now find out the maximum force to be applied to the ball screw, this may be the inertia force, or machining force: F max  MAX ( M a ; F max,machining ) The preload force should be at least: Ball screw fatigue life depends on the entire duty cycle, although initially, a ball screw with a preload of 8% of dynamic load can be chosen, and therefore: In the Load and Dimension tables, two or three combinations can be selected that meet this condition. From the tables d 0 ; D w ; i The shaft lead must comply with: From the DN table on page 50 maximum rotation speed is obtained in order to keep temperature under control, according to lubrication type and ball recirculation system. It is recommended not to work over 75% of limit speed: · Without Preload: Loading and transport ball screws, Technologies IML, HDL, PKL, TMBS The first thing is to choose the lead (P h ) according to N advised , and then in the tables choose a combination (d 0 ; D w ; i) so that C oa > 5*F max , and calculate life with the cycle to verify that it is sufficient. If it is required a shorter lead or a higher rotation speed, it is recommended to refer the case to SHUTON·IPIRANGA for a detailed study. The greater P h , the lower the temperature and noise and longer the life. Fatigue life and rigidity can be calculated with d 0 , P h , D w , i . (see pages 39-42) If fatigue life is low, N can be reduced with a greater P h value, or if not choose a ball screw with a higher dynamic load C a , increasing d 0 , D w or i . Also F pr can be reduced at the expense of less rigidity. If ball screw rigidity is low, check which is most important, shaft rigidity or nut rigidity. If it is the shaft then it can be pretensioned or the nominal diameter d 0 increased. If it is the nut increase d 0 or i, or also increase F pr at the expense of reducing fatigue life. Lastly, check static load, bending, critical rotation speed and deflection or radial deformation; in case it is necessary to carry out one of the following actions: · Increase the nominal diameter d 0 · Use a rotating nut · Change the support mounting method · Insert a rest or intermediate support e.g. M:2000kg, v:50m/min, a:5m/s 2 , Fmec,max:15000N without axial play Preload & high speed COMPLEX family Inertia force: F in  Ma = 2000 x 5 = 10000 N F max = 15000 N C a ≥ 4,5 x 15000 = 67500 N Can be: A/ d 0 : 40 - D w : 6,35 - i: 5 B/ d 0 : 50 - D w : 6,35 - i: 4 C/ d 0 : 50 - D w : 7,938 - i: 3 Speed is high, and therefore we will use external ‘U’ recirculation and oil lubrication. DN: 180000 For the nut to be as short as possible, we start with option C, d 0 :50 - D w : 7,938 - i: 3 With P h : 20 it is sufficient, although if we use P h : 25 , fatigue life, temperature and noise will improve. F pr ≥ F max 2,83 F pr ≥ = 67500 N 15000 2,83 P h ≥ v N advised C a ≥ 4,5 F max C a ≥ F max 2,83 x 0,08 C a  F pr 0,08 P h ≥ = 18,5 50 x 1000 2700 N advised = 0,75 x = 2700 180000 50 N advised = 0,75 x N lim = 0,75 DN d 0 Quick selection of a ball screw 23