By the product of on-site technical research, after repeatedly exploration and production verification, summed up a more reliable method of assembly process.
1, First, use the overall style special mandrel for screw base hole calibration, the positive and lateral parallelism with the reference guide at 0.01/1000 or less;
2, After fixation of the nut seat, using professional measuring fixture actual measured positive and lateral distance of reference guide with the nut seat pitch; then, the same use the overall style special mandrel for the alignment of bearing bore and the reference guide positive and lateral side parallelism is 0.01/1000 or less, using a dedicated measuring fixtures actually measure the positive and lateral side of the reference guide rail from the bearing pitch, requires the nut hole with a reference guide positive, lateral distance consistent, tolerance for 0.01; the bearing pedestal is fixed. This method uses overall style special mandrel, not only the length of the short, and the mandrel and the positioning sleeve into one, eliminating the fit gap between the mandrel and positioning sleeve, reliable ensures the parallelism of bearing hole, a screw nut seat hole and guide;
3, By measuring the actual distance, so that both ends of the bearing bore and nut seat hole concentricity has been a reliable guaranteed, thus reducing the deflection of the ball screw and radially offset load and improve the screw installation precision.
4, In addition, during the installation of ball screw, axial runout of the ball screw must be strictly controlled, the technology index will directly affect the ball screw feed system transmission position accuracy. According to the actual verification showed that: first, to install the bearing within the assembled servo motor end bearing, that plays a major role in the process of rolling screw drive, the axial runout of ball screw controlled between 0.015 ~ 0.02; then, install the bearing in the other end of the bearing assembly, so that the axial runout controlled in less than 0.01. This will effectively ensure the stiffness and accuracy of the ball screw feed system.
5, The ball screw shaft prestretching is also very necessary. To improve the ball screw feed system stiffness and accuracy, implement pre-stretch to the screw shaft is very effective, but due to the different sections of the screw shafts, and it is not easy to precisely set the temperature rise, so the pretension force calculation according to the literature only as a reference amount. In production is often the target value of the screw shaft having a negative direction of pre-stretching, to make to the machine tool table positioning accuracy of the curve nearly horizontal.
Source: http://www.machineballscrew.com precision ball screw assembly manufacturer.
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