油菜联合收获机往复式双动割刀行星轮驱动器设计与试验

为解决传统油菜联合收获机往复式切割器因横割刀振动大、刀片对油菜茎杆扰动引起的割台落粒损失大、切割功耗高等问题,该研究设计了双动割刀行星轮驱动器。通过建立行星轮驱动机构运动方程,分析了驱动机构须满足的割刀运动结构参数。对行星轮驱动式双动割刀所受惯性力及切割图的分析表明,刀杆往复运动产生的惯性力是引起割刀产生振动的主要原因,且行星轮驱动式双动割刀具有惯性力平衡性能好、切割冲击小、对油菜茎秆扰动小及割刀切割连续性高等特点。茎秆切割功耗测试结果表明,割刀切割速度在1.2、1.4、1.6 m/s范围内,行星轮驱动式双动刀相对曲柄连杆驱动式单、双动刀切割器功耗平均分别降低了43.3%和16.8%。相同割幅的行星轮驱动式双动割刀和曲柄连杆式单动刀空转状态振动测试表明,割刀切割速度在0.8、1.2、1.6 m/s时,同一振动测点处安装有行星轮驱动式双动刀的割台较安装有曲柄连杆式单动刀切割器的割台所受割刀往复运动方向振动平均降低了56.3%。油菜联合收获田间试验结果表明:安装有行星轮驱动式双动刀的割台所受割刀往复运动方向的振动较安装有曲柄连杆式单动刀的割台降低51.2%;机器前进速度0.6~1.4 m/s时,行星轮驱动式双动割刀割台落粒损失最小为1.56%,最大为2.68%,较曲柄连杆式单动刀割台落粒损失平均降低42.5%。理论分析、室内试验及田间试验结果均表明,所设计的行星轮驱动式双动割刀振动小、功耗低、作业性能稳定,降低割台落粒损失效果明显。

Design and test of planet gear driver of reciprocating double-acting cutter for rapeseed combine harvester

Abstract: In order to solve the problems, such as serious vibration, high rapeseed loss rate of header and the high cutting power consumption, caused by the single-acting reciprocating cutter of the traditional rapeseed combine harvester, the planet gear driver of the reciprocating double-acting cutter was designed and tested. Firstly, kinematic equation of planet gear driver was established, and the structural parameters of the planet gear driver of the reciprocating double-acting cutter which must satisfy the requirement of cutter kinematics were analyzed. The analysis of the inertia force, and cutting trajectory and cutting area of the double-acting cutter showed that the inertia force generated by the reciprocating motion of the cutter bar was the main vibration source of the cutter. And the planet gear driven double-acting cutter''s characteristics of good balance of inertia force, small cutting impact, light disturbance to the rape stalk and high cutting continuity were verified. Moreover, the bench experiment of power consumption for rape stalks cutting was done to compare the mean power consumption of the planet gear driven reciprocating double-acting cutter with that of the crank-linker driven single-acting cutter and double-acting cutter. When the cutting speed was in the range of 1.2~1.6 m/s, the average power consumption of the planet gear driven double-acting cutter was 43.3% and 16.8% lower than that of the crank-linker driven single-acting cutter and double-acting cutter, respectively. Furthermore, in order to test the vibration acceleration of the planet gear driven double-acting cutter and the crank-linker driven single-acting cutter, the two cutters were installed on the header of NJS-2.2 self-propelled rape combine harvest test bench respectively. When the speed of the cutter was in the range of 0.8~1.6 m/s, the average vibration acceleration of the planet gear driven double-acting cutter was 56.3% and 51.2% lower than that of the crank-linker driven single-acting cutter at the same vibration measuring point and in the same direction, respectively in the idling state and working state in the field experiments. Then, in order to research the other working performance between the planet gear driven double-acting cutter and the crank-linker driven single-acting cutter, the field experiments of the rapeseed loss rate of header were carried out. The results showed that the minimum and the maximum of the loss rate of header with the planet gear driven double-acting cutter were 1.56% and 2.68% respectively, which was 42.5% lower than that of the header with crank-linker driven single-acting cutter when the forward speed of the harvester was in the range of 0.6~1.4 m/s. The theoretical analysis, laboratory experiment and working state experiment in the field showed that the planet gear driven double-acting cutter designed in the study had the advantages of smaller vibration acceleration, lower power consumption, stable working performance, and obvious effect on reducing the rapeseed loss rate of header for rapeseed combine harvester than that of the crank-linker driven single-acting cutter. Thus it indicated that the planet gear driven double-acting cutter had the value of further improving and promoting application.