长期以来,在凸轮机构中用压力角α;在连杆机构中用传动角γ(因为丨90°-γ丨=α,实质上仍是压力角)作为衡量机构传动质量的指标和设计依据。本文通过分析,指出了压力角作为这种指标的缺陷和提出了新的机构传动质量指标Ψ’=tga’tgφ’,其中α’为实际压力角,φ’为从动件与机架间的当量摩擦角。文章还阐述了新指标在机构分析和综合上的应用。 For a long time, the cam mechanism with the pressure angle α; in the link mechanism with the transmission angle γ (because 丨 90 ° -γ 丨 = α, essentially pressure angle) as a measure of transmission quality indicators and design basis. This paper points out the defects of the pressure angle as the index and puts forward a new transmission quality index Ψ ’= tga’tgφ’, where α ’is the actual pressure angle and φ’ is the distance between the follower and the rack Equivalent friction angle. The article also elaborates on the application of new indicators in institutional analysis and synthesis.