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Cam indexer drive angle

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Update time : 2019-05-13 20:31:52
Speaking of the driving angle of the Cam indexer, it is necessary to talk about the working principle of the splitter. As a type of rotary device, the splitter is a continuous rotation of the input shaft under the action of the motor as the drive source, thereby achieving the intermittent, swaying of the output shaft. The indexing action of lifting or continuous, etc., the driving angle mentioned here is only related to the input shaft.
Cam indexer drive angle physical map
In theory, a complete mechanical action is used to describe the driving angle. The input shaft rotates 360 degrees a cycle. At this time, the output shaft completes a motion stop action, and the output shaft motion is the input shaft. When the angle of the output shaft is rotated, the angle at which the input shaft rotates is the driving angle. Therefore, when the input shaft rotates 90 degrees, the output shaft rotates by one station, and the remaining 270 degrees is the angle of repose of the input shaft, which is also the stopping process of the output shaft. By analogy, when the driving angle is 120 degrees, 150 degrees, 180 degrees, 210 degrees, 240 degrees, 270 degrees, 300 degrees, 330 degrees, 360 degrees, the corresponding angle of repose is 240 degrees, 210 degrees, 180 degrees 150. Degree, 120 degrees, 90 degrees, 60 degrees, 30 degrees, 0 degrees, etc., as shown below:
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It can be seen from the above data that the rotation of the input shaft is constant at one time, and the speed of the continuous rotation of the input shaft under the driving of the motor is theoretically constant, so that the driving angle and the angle of repose of the input shaft rotation are generated. The ratio is also constant, which is what we call the dynamic stop ratio of the output shaft. When the driving angle of the input shaft is 120 degrees, then the angle of repose is 240, then the ratio of the stop to the stop is 1:2, and the splitter output shaft rotates. When the time is 1 second, then the rest time is 2 seconds. When the driving angle of the input shaft is 180 degrees, the dynamic stop ratio of the output shaft is 1:1.
How to choose the driving angle? In the choice of driving angle, combined with the actual use requirements, speed and load are the factors that have a great influence. As shown in the following figure, the cycle of the input shaft rotating within 360 degrees can be seen that the driving angle θh of the input shaft is higher. In the large case, the slope of the curve is longer, and the curve of the rotating spiral groove of the cam is longer, so that the curve of the motion is gentler. At the intersection of the driving line and the stopping line of the input shaft, the buffering force of the cam and the roller will be smoothly transitioned. In the case where θh is small, the slope of the curve is steep, and a large impact occurs at the intersection of the drive line and the stop line of the input shaft. Therefore, the larger the drive angle, the whole drive mechanism will run. The more stable. Therefore, when selecting the driving angle, it is more stable to choose a larger driving angle. Some high-speed splitters, for example, 0.1 second, 0.2 second dynamic stop, large drive angle will also affect the speed of the splitter operation, so the splitter's own quality requirements are higher, such as cam Materials, processing techniques and equipment, etc., in actual use, high-speed operation of the system, due to improper selection of drive angles, splitter quality and other factors caused by equipment running jitter phenomenon. For the case where the speed requirement is not very high and the machining time is relatively long, most of the suggestions are to choose a larger drive angle, because in this case, the output shaft stop angle of the splitter in the automation system is mostly controlled. Device.
In the above description of the driving angle, there is also a case where the driving angle is 360 degrees, that is, the input shaft continuously rotates, and the output shaft does not stop. The splitter here is actually a function of the speed reducer, in practical application. The servo drive will be used, combined with the stable operation and high torque of the splitter to achieve positioning at any point.