【正文】 ..................................................................I Chapter 1 Introduction .................................................................. 1 Topics significance .............................................................. 1 CNC system development history ........................................ 1 Domestic NC State Analysis ................................................ 2 CNC system development trend ........................................... 2 O rdinary machine tool CNC transformation of the need ....... 3 Chapter 2 The overall program design .......................................... 4 C alculate parameters and technical requirements ................. 4 O verall planning .................................................................. 4 Feed motor servo system reconstruction design .......... 5 Couplings .................................................................. 5 The size parameter .............................................................. 7 The motion parameters ........................................................ 7 The dynamic parameters ...................................................... 8 Calculate the motor power ......................................... 8 Calculate the speed .................................................... 9 Chapter 3 Calculate of the feed syste m ....................................... 10 Traverse to the design of drive chain ................................. 10 The calculation of the main cutting force ................. 10 Calculate the cutting force ....................................... 10 The rail fr iction calculation ............................................... 11 C alculate the coordinates of rail friction in cutting state .................................................................................... 11 Axis without cutting state rail friction calculation .... 12 Alculate the ball screw pair of axial load force .................. 12 The maximum axial load force calculation ............... 12 The minimum axial load power calculation .............. 13 CM6132 型精密車(chē)床進(jìn)給系統(tǒng)的數(shù)控改造 VII Determine the feed drive chain gear ra tio and transmission series ......................................................................................... 13 The ball screw estimates .................................................... 14 Estimate the ball screw expected dynamic load rating ........................................................................................... 14 Estimate allows the ball screw axial deformation ..... 16 The precision to determine the smallest thread of the ball scre w allow bottom diamete ......................................... 17 The preliminary to determine the accuracy class of the ball screw nut ................................................................................... 18 Determine the specification model of the ball screw nut .... 19 The vertical feed system design and calculation ................. 19 Dall screws for bearing capacity check .............................. 19 The ball screw nut critical pression load calibration ........................................................................................... 19 The critical speed of the ball screw nut checksum .... 20 Dall screw pair rated life C heck ..................................... 21 Calculate the mechanical transmission system of stiffness 22 Calculate the mechanical transmission system of stiffness .............................................................................. 22 C alculate the stiffness of the ball screw nut supportin g bearing ................................................................................ 23 .3 Calculate the contact stiffness of the ball and the raceway............................................................................... 24 C alculate the feed drive system inte grated tension and pression stiffness .......................................................... 25 Calculate the torsional stiffness of the ball screw nut ....... 26 Chapter 4 drive motor selection and calculation ......................... 27 The calculation of muted to the motor shaft load moment of inertia ................................................................................... 27 A single rotary part of the moment of inertia calculation .......................................................................... 27 CM6132 型精密車(chē)床進(jìn)給系統(tǒng)的數(shù)控改造 VIII The moment of inertia of moving parts, converted to motor shaft.......................................................................... 27 Increase the total load on the motor rotation inertia calculation .......................................................................... 28 C alculate the load torque converted to motor shaft ............ 28 Converted to a motor shaft of the cutting load torque calculation .......................................................................... 28 Converted motor shaft friction load torque calculation ........................................................................................... 29 Generated by the ball screw preload and calculation of load torque converted to motor shaft ................................... 29 Converted to motor shaft load moment of calculation ........................................................................................... 30 Calculation of converted to electric on the shaft of the accelerating torque .................................................................... 30 S elect the model of the drive motor ................................... 31 Select the model of the drive