Under what circumstances will the ball screw deform due to thermal stretching? After practical experience with the manufacturer and feedback from customers, it has been concluded that ball screws only experience thermal stretching when operated for long periods of time or under overload conditions. If the workload far exceeds their own bearing capacity and we fail to detect it in a timely manner, the ball screw will increase its operating force during normal operation, and the friction coefficient will increase. Gradually, heat will be generated, and if this heat cannot be improved or controlled for a long time, the screw will deform due to thermal stretching over time. In order to prevent the screw from being stretched due to heat, ensure the accuracy of screw use, and extend its service life, we must consider the design based on the load of the machine when selecting, and regularly clean and maintain the machine to ensure its working performance. We can control it first-hand from the following points!
(1) Control heat generation:
The heat generated by the ball bearings and the preload of the supporting bearings should be correct and appropriate.
The correct selection and appropriate supply of lubricants.
Increase lubrication to increase the lead of the bead screw and reduce the number of rotations.
(2) Apply forced cooling:
The screw shaft is hollowed out and filled with coolant.
The outer edge of the screw shaft is cooled with lubricating oil or air.
(3) Avoid the influence of temperature anomalies:
Warm up the machine to the desired temperature at high speed.
A stable state is more useful
Pre tension is applied when installing the screw shaft
The target value for cumulative lead is set to a negative value in advance
Use the idle loop method for positioning.
