【摘要】 <正> 单相永磁步进电动机,具有结构简单、控制方便、功耗小、有固定转动方向、以及工作可靠等特点。应用于一些仪器、仪表及计时装置中,受到一定的重视。近年来,由于指针式石英电子手表发展的需要,对这类电动机进行了一系列的研究工作,出现了繁多的结构型式。为了使单相永磁步进电动机有固定的转动方向,以及带负荷启动的能力,通常采取二种办法。即加辅助磁极(定位极),或者让主磁路有一定的不对称性。后一种办法用得更经常一些。例如:定子极弧由半径不等的同心圆弧段组成的“大小气隙式”;定子极弧与转子外圆不同心的“偏心式”;定子极弧的一面被削去一块的“削角式”;定子分成大小极且大极上有一较深裂口的“单裂极式”;定子二个极上各有一个凹坑的“双凹坑式”;定子二个极上共有一个凹坑的“单凹坑式”等等都属于这一类,本文把它们统一称为不均匀气隙的电动机。更多还原

【Abstract】 This paper presents a simplified magnetic field model of nonuniform air gapPM step motor using the concepetion of“magnetic circuit element”.Based on themodel a general static torque formula is derived which can be applied to varioussiluations of nonuniformity.Through the analysis of the static torque characteristics of both the uniformand nonuniform air gap motors by used the given formula,it can be shown clearly,how the structure parameters give effects on the torque—angle characteristicswhich is very interesting to designers.In order to get a more implicit model,a simplified method to account theend-effect of the motor is incorporated.The experiment shows that,this method has a sufficient accuracy for engi-neering calculation.更多还原