S99TE14-0710

Ballscrews ( complete program ) - 14370 11

(10) Excessive preload increases the friction torque and generates heat which reduces the life expectancy. But insufficient preload reduces stiffness and increases the possibility of lost motion. Recommends that the maximum preload used for CNC machine tools should not exceed 8% of the basic dynamic load C.(11) When the nut needs to be disassembled from/assembled to the screw spindle, a tube with an outer dia. 0.2 to 0.4 mm less than the root diameter (ref. M39) of the balltracks should be used to release/connect the nut to from/to the screw spindle via one end of the screw spindle shown in Fig. 4.9.(12) As shown in Fig 4.10, the support bearing must have a chamfer to allow it to seat properly and maintain proper alignment. HIWIN suggests the DIN 509 chamfer as the standard construction for this design (Fig. 4.11). RA tube

Fig 4.9 The method of separating the nut from the screwspindle Fig 4.10 Chamfer for seating the face of bearing end Fig 4.11 Suggested chamfer dimension per DIN 509 for the “A” dimension in Fig 4.10