中文摘要：

为实现玉米脱粒机脱粒间隙可自动调节,减小玉米脱粒过程中的机械损伤,设计了浮动式玉米单穗脱粒装置。该脱粒装置主要由间隙浮动调节装置、喂入料斗、离散辊、脱粒辊和差速辊等组成,具有脱粒间隙自动调节和玉米果穗喂入自动分离、逐个排出功能。选取离散辊转速、脱粒辊转速和差速辊转速为试验因素,以玉米籽粒的破损率和未脱净率为试验指标,采用二次回归正交旋转组合的试验方法,对浮动式玉米单穗脱粒装置进行了参数优化试验。优化结果为：离散辊转速为234 r/min、脱粒辊转速为511 r/min、差速辊转速为91 r/min,在最优参数组合下的实际籽粒破损率为0.25%、未脱净率为0.76%、玉米芯完整度为100%。

英文摘要：

In order to solve the problem that corn thresher can not automatically adjust the threshing clearance and reduce the mechanical damage in the process of corn threshing,the floating corn single panicle threshing device was designed. The threshing device was mainly composed of clearance adjustment device, feeding hopper, discrete roller, threshing roller, differential roller, etc. The clearance adjustment device could float and automatically adjust threshing clearance. It can adapt to the differences in the diameters of corn ears,which was conducive to reduce broken rate and increase threshing rate. When the water content of grain was below 25% and the speed of discrete roller and threshing roller was not more than 800 r/min,the threshing device did not result in the fracture of corn cob. The feeding hopper realized the function of automatic separation of corn ears and discharge one by one. The optimum tilt angle of feeding hopper was 40° and the feeding height of corn ear was 132 cm.Three parameters,including discrete roller speed,threshing roller speed and differential roller speed were selected as the input variables,and broken rate and un-threshing rate of corn grain were used as the test indexes. Parameter optimization experiment was completed on the floating corn single panicle threshing device by the method of quadratic regression orthogonal rotary combination. The optimization results showed that the discrete roller speed was 234 r/min,the threshing roller speed was 511 r/min and the differential roller speed was 91 r/min. The actual grain broken rate was 0. 25%,the actual un-threshing rate was 0. 76% and the integrity rate of corn cob was 100% under the optimal parameter combination.