The ball screw is stuck
As we all know, ball screw has been widely used in practical production, but ball screw often appears stuck phenomenon in the assembly process. Once the ball screw stuck, to continue to use the screw, but this brings great trouble to the assembly of the ball screw. Ball screw pair will also appear stuck in the process of use, resulting in abnormal equipment work. In this regard, the ball screw manufacturer thinks that the reason for the jam is caused by the lack of precision of parts in manufacturing, but it can not make a reasonable explanation for the jam mechanism. Although the research on ball screw has been quite extensive at present, there are few research papers on ball screw sticking problem. Today we will analyze the cause of screw pair stuck is very necessary.
In actual production, all kinds of ball screw pairs are stuck, and can be controlled within 3%. The ball screw is stuck and the ball screw is caused by poor assembly quality, poor flexibility and poor operation, and the ball screw can not rotate relative to the nut after being stuck. At this time, assemblers often use percussion and vibration methods to loosen the jammed screw pair, but most of them are ineffective. Through the actual investigation of different types and different geometric parameters of ball screw stuck state, found some characteristics of ball screw stuck. Stuck with almost the phenomena of screw tbi screw Angle and lead is independent of the size, the manufacture of high precision ball screw pair of card death occur probability is low, after the preloaded ball screw pair are apt to happen stuck phenomenon, single circular groove guide screw pair is double circular arc raceway lag screw pair are more likely to happen, all kinds of reverse type of ball screw pair are stuck phenomenon. It needs to be emphasized that the forward and inverse movement of the ball screw pair can not be carried out, no matter whether the screw or the nut is the active part, and no matter how much the driving torque is, the screw and the nut can not produce relative movement.
Because the ball screw pair has a very high transmission efficiency, generally more than 90%, in principle, the ball screw will not appear stuck. Therefore, the phenomenon of ball screw stuck must be analyzed from the manufacturing error and assembly of its parts. In addition, in view of the actual situation that the ball screw pair can not be loosened after increasing the driving torque and its forward and inverse motion can not be loosened, there are only two possible reasons for the jam, that is, mechanical jam and self-lock.