Study And Design Of Speed-change Cylinder Mechanism On Comber

In modern spinning system, people consider combing to be the heart. The technics require the new comber must have high yield and high quality. Now the combing machine which made in China, exists defect in upraising inadequacy of comber web at the lap joint time, and cylinder catches away reversed combed web from detaching roller and so on. In this thesis, using speed-change cylinder mechanism to change the cylinder transmission law for improving quality of combed sliver.Comber speed-change cylinder is achieved by the periodic variable of transmission ratio of elliptic gear. And use MATLAB software to program and calculate, then analyze design method of the mechanism, discuss the effect of eccentricity for speed-change cylinder, and determine optimum design parameter of combing process. The technology of cylinder, detaching roller and nipper are studied, and then technological parameters such as the timing of combing with cylinder speed change, the timing of the last row of needle on cylinder through detaching roller, and the combing gauge are analyzed.The results show: speed-change cylinder mechanism which used the elliptic gear to suit combing process. Cylinder runs high speed on cylinder combing stage, and runs low speed on preparing before detaching stage, so the timing was distributed more reasonable in a work cycle of comber. When eccentricityλ=0.1 of cylinder speed-change mechanism, preparing before detaching time was increased from 12.21 index to 14.43 index, and the raising top time of nipper web is extended and the raising top fully, so forming hooks when the new web crashed into the returned web is avoided. The end timing of cylinder combing is bring forward from 5.93 index to 3.71 index, meanwhile the last row of needle on cylinder passes detaching roller earlier, cylinder catches away reversed combed web from detaching roller is effectively avoided. For detaching roller technics, if use 90°speed-change cylinder, the timing of rotating in the forward direction is not influenced by cylinder location, the quality of combed sliver is raised by use earlier timing of rotating in the forward direction, then to improve the joint thickness. 110°cylinder has wider application range, and can effectively increase the cylinder combing degree, fiber straightness, parallelism and resolution, the combed sliver and yarn quality. For the influence of eccentricity to cylinder motion, the larger eccentricity of elliptic gear, the shorter time of cylinder combing stage on comber, the longer time of preparing before detaching and lapping stage, and the earlier time of the last row of needle though the least gauge point of detaching roller; but angular acceleration of cylinder is rapidly increase in the mean time. Therefore, choosing smaller eccentricity of elliptic gear is well under the condition of meeting comber process requirement. The maximum value, difference value of maximum and minimum value, and medium value of combing gauge are gradually diminish with larger eccentricity of elliptic gear, that is advantage to cylinder equally load combing and raise the quality of combing.