Maintenance experience in screw

Maintenance experience in screw - 2019 04 - 30 ball screw fault is generated by a variety of, have no fixed pattern. Some fault is gradually developed, should have a process of development, with the increase of use time more and more serious; Sometimes sudden fault, generally no obvious signs, and suddenly, the fault is all sorts of unfavorable factors and outside work together. So the right tests to determine the real cause of the problem, is the precondition of rapid accurate maintenance. The picture shows red eagle T series T2613 internal structure here to share the following inspection and maintenance of the ball screw is: 1) Ball screw nut pair of support system and detection and repair when accuracy of nc machine tools in reverse, positioning accuracy is not stable, quadrant appearance mark, first to test for a screw system for clearance. Testing method: use dial indicator with steel ball on one end of the screw in the center hole, measure the screw's axial channeling, another piece of dial indicator to measure moving workbench. Positive and negative rotation screw, observation on two small dial indicator reflects the values, according to the different changes of numerical confirmed failure parts. 一) Screw support bearing clearance inspection and repair, such as measuring dial indicator of a ball screw in the screw forward and reverse rotation pointer swing, that screw without moving. Such as the dial indicator pointer swing that screw has a dynamic phenomenon. The dial indicator is the difference between the maximum and minimum measured value is the screw's axial moving distance. At this time, we will check whether support bearing back cap lock, have support bearing wear failure, additive load bearing washer. If the bearing is no problem, as long as to deserve to be additive load washer is ok. If the bearing is damaged, need to replace the bearing, to deserve to be additive load washer, keep back cap back again. Screw axial channeling dynamic size precision mainly depends on the support bearing additive load washer. Screw installation precision is the ideal state of no positive and negative gap and support bearing have 0. 02 mm interference. Adopt Taiwan on silver bar b) Ball screw double nut vice produce clearance by testing, inspection and maintenance if confirm the fault is not caused by screw up move. That is about to consider whether the space between the lead screw nut pair, the detecting and testing method of this kind of circumstance screw up still the same. Connected to the nut of the worktable is measured with a dial indicator, forward and reverse rotation screw, detect the biggest gap between screw and nut, and then to adjust. c) Inspection and maintenance of the single nut pair for a nut ball screw, screw nut pair between the gap can not be adjusted. Such as detection of screw nut pair clearance exists. First check to see if the threads of the screw and nut circular arc has been wear and tear, such as serious wear and tear, and must be replaced a full set of screw nut. Such as check wear slightly, can replace larger the diameter of the ball to repair. First to detect the lead screw nut pair of maximum clearance, converted to the increase of the ball diameter, and then selecting the right ball assembly again. Such maintenance is more complex, the required time is long, requires high technical level. d） Nut flange connected to the workbench of no fixed gap this problem generally easy to miss, because of long-term reciprocating motion machine, fixed ferrari plate screw loosening clearance, when check the screw nut clearance first exclude the first failure factors, in order to avoid detours during repair. e) Ball screw nut pair movement of fault maintenance is not steady, the noise is too large. Ball screw nut pair of movement is not smooth and too much noise, is mostly caused by poor lubrication, but sometimes can also be caused by servo motor drive parameters to adjust. 2) Poor lubrication bearing, ball screw nut pair in the work, such as noise and vibration of the machine tool in the detection of mechanical transmission parts is no problem, the first thing to consider to the problem of poor lubrication, many machine after many years of operation, screw nut, the automatic lubrication system often jams, automatic lubrication. Can join in the bearing, nut resistance to high temperature, high speed of grease can solve the problem. Bearing grease can guarantee the normal operation for several years, nut. 3) Servo motor driver problem some machine to produce vibration and crawling in sports, often detect mechanical parts have no problem, no matter how to adjust all cannot eliminate the vibration and crawling. After carefully check, found that the servo motor driver gain parameters are not suitable for the actual operation condition. Adjusted gain parameter, you can eliminate vibration and crawling. （ Source: carved CNC)