犁耕和旋耕作业发动机载荷的统计特性

了解发动机载荷动态特性是对发动机及机组系统进行动态性能分析和动态匹配的前提。该文根据对田间试验和土槽试验数据的各种统计检验,总结了犁耕和旋耕作业时发动机载荷阻转矩的一些基本的统计特性。证实了犁耕作业发动机的载荷可以认为是平稳的正态分布的随机载荷,其功率谱曲线的谱峰在低于2Hz处;旋耕作业发动机的载荷是兼有随机成分和周期成分的动态载荷,其中周期谐波的基频为刀轴转速,随机成分一部分能量集中于基频以内,部分分布于较宽频率范围。在常用的速度范围内,犁耕发动机载荷以及旋耕发动机载荷的低频随机成分的功率谱均可以采用一种单峰谱函数拟合

Statistical Properties of Working Load of Engine in Plowing and Rototilling

The knowledge of the dynamics of engine working load is essential condition for dynamic analyzing and matching for engine and tractors. In this paper, according to the statistical examination of the experimental data in field and laboratory test, the fundamental statistical properties of working load of engine in plowing and rototilling are summarized. The working load of engine in plowing can be taken for stable and normal random load whose power spectrum peak value is below 2 Hz. The working load of engine in rototilling contains both periodic element whose fundamental frequency is rotating speed of the blade shaft and normal random load of which the parts of energy centers in fundamental frequency and others are distributed over wider frequency band. In frequent speed the power spectrum of the engine load in plowing and the low random element of the engine load in rototilling can be simulated by a single peak spectrum function.