Accuracy Analysis of Cam Indexer

The indexing accuracy of the cam indexer refers to the difference between the theoretically required rotation angle value and the actual rotation angle value when the indexing table is indexing. In the automatic turntable, the cam indexer is a kind of high-precision transmission part of intermittent rotation. Due to load and speed, it requires high positioning accuracy. At the same time, it is also an important factor in determining the product quality of the indexer.

The unit of precision. The rotation angle of the indexer is used to weigh the precision parameters. Generally, it is expressed in angle seconds, and it is also expressed in millimeters. The so-called angle second is a precision unit. We are used to express it with the symbol ". In actual production applications, the second is the accuracy index that the cam indexer can achieve. In a circle, its rounded corner is 360 Degrees, if you convert this degree to seconds, then 1 degree is 3600 seconds, so the unit of 1 second is very small. From this point of view, the precision of the indexer is the smaller the number of seconds, then its precision is Higher.

From the above analysis, we can see that the accuracy of the cam indexer is determined by the indexer itself, and has nothing to do with those of the motor. The internal structure of the planar indexer is the turret and the cam. The internal structure is very simple, but the precision is very high. As for the additional limit and sensor, it is because you may stop the one-sided time of each station during the work process is different, so you need to use the sensor to feedback information to the motor, and stop or decelerate the motor to achieve the goal.

In addition, the accuracy of the cam indexer is related to the cam roller of the cam turret. Generally, the cam turret is carburized and ground. The surface of the turret that uses carburized grinding and fine grinding is smooth and flat. The indexer produced in this way has a high accuracy. , Some small workshops still use desalinated cams, which are rough, uneven, and have large gaps, so the precision of the indexer made is not high. In addition, during the assembly process, the production and assembly must be processed strictly in accordance with the production process. The wrong assembly method will also affect the accuracy of the cam indexer!

The calculation method of the disc edge accuracy, the radial error and the axial error of the drive disc are one of the signs that reflect the performance and stability of the cam indexer. What is reviewed here is the radial error value reflected by the edge of the disc using the indexer during the rotation process.

The precision expression unit of the indexer is the angle system, which is usually calculated by 360 degrees in a circle of the disc, 1 degree is 60 minutes, and 1 minute is 60 seconds. The distance reflected on the edge of the disc is what we call the arc distance. Therefore, the smallest unit is called arc second, and the unit is arc-sec. The accuracy of the commonly used model of Kemder indexer is calculated as ±30arc-sec, then its accuracy coefficient is a=1/360*1/60*1/ 60*30″ So, combined with the above formula, the diameter of the disc is 1M, then the total length of the disc is πd in one revolution, and its error is calculated as πda=3.14*1*1/360*1/ 60*1/60*30″=0.0000727m, its angle error is 0.0727mm.