What Is Indexing Accuracy in Cam Indexers?
The indexing accuracy of the cam indexer refers to the difference between the theoretical required rotation angle value and the actual rotation angle value when indexing the indexing table. In an automatic turntable, the cam indexer is a high-precision transmission part that rotates intermittently. Due to the load and speed, it requires a high positioning accuracy. At the same time, it is also an important factor in determining the quality of the indexer product.
How Is Cam Indexer Accuracy Measured?
The angle of rotation of the indexer is used to weigh the accuracy parameters. It is generally expressed in angular seconds, but also in millimeters. The so-called arc second is a unit of precision. We are accustomed to expressing it in symbols". In practical production applications, the second is the accuracy index that can be achieved by the cam indexer. In a circle, its rounded corners are 360 degrees, and 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 smaller the precision of the indexer and the smaller the number of seconds, the higher its precision.
Which Factors Affecting Cam Indexer Accuracy?
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 the accuracy of the motor. The internal structure of the plane indexer is the turret and cam. The internal structure is very simple, but the precision is very high. As for the additional limit and sensor, because the one-sided time of each station may be different during the working process, it is necessary to use the sensor to feed back the information to the motor, and stop or reduce the motor to achieve the purpose.
In addition, the accuracy of the cam indexer is related to the cam rollers of the cam turret. Typically, cam turrets are carburized and ground. Carburized and finely ground turrets have a smooth and flat surface. The indexers produced in this way have a high degree of precision. , some small workshops still use faded cams, rough, uneven, large gaps, so the accuracy of the indexer made is not high. In addition, in the assembly process, production and assembly must be processed in strict accordance with the production process. The wrong assembly method can also affect the accuracy of the cam indexer!
The calculation method of disc edge accuracy, radial error and axial error of the drive disc is one of the signs that reflects the performance and stability of the cam indexer. What is reviewed here is the radial error value reflected from the edge of the disc using the indexer during rotation.
Calculating the Accuracy of the Cam Indexer's Drive Disc
The precise unit of expression of the indexer is the angle system, which is usually calculated as 360 degrees of a disc in one circle, 1 degree is 60 minutes, and 1 minute is 60 seconds. The distance reflected at the edge of the disc is what we call the arc distance. Therefore, the smallest unit is called arc seconds, and the unit is arc seconds. The accuracy of the commonly used models of Kemder indexer is calculated as ±30arc-sec, then its accuracy coefficient is a=1/360*1/60*1/ 60*30" Therefore, combined with the above formula, the diameter of the disc is 1M, then the total length of the disc is πd to make one revolution, and its error is calculated as πda=3.14*1*1/360*1/60*30"=0.0000727m, and its angle error is 0.0727mm.