Abstract:  In view of the problems of low compression ratio and small displacement volume of equal wall thickness profiles， the gas force of the variable wall thickness profile changed greatly and it was difficult to machine and measure， a design method of asymmetric equal wall thickness profiles was proposed using base circle involute. Using this method， the fully engaged asymmetric scroll teeth with equal wall thickness were established， and the calculation formula of the working chamber volume was derived. The dynamic change processes of the axial， tangential and radial gas forces exerted on the orbiting scroll tooth were obtained with the spindle angles. The results show that compared with the traditional scroll profiles with equal wall thickness and variable wall thickness profile， the displacement volume of the newly constructed asymmetrical scroll profiles with equal wall thickness is increased by 25.99% and 7.82% respectively， and the compression ratio is increased by 19.70% and 2.04% respectively. While the variation range of the axial， tangential and radial gas forces is significantly reduced. It also shows that the asymmetric scroll profiles with equal wall thickness may give better consideration to the advantages of the traditional profiles， and has more superiorities in volume performance and dynamic performance. 

Key words: base circle involute, asymmetric profile with equal wall thickness, scroll teeth, variable wall thickness profile, gas force

摘要： 针对现有等壁厚型线压缩比小、行程容积小，变壁厚型线气体作用力变化幅度大、加工测量困难等问题，提出了一种采用基圆渐开线构建非对称等壁厚型线的设计方法。利用所提方法建立了一种全啮合的非对称等壁厚涡旋齿，并推导出工作腔容积计算公式，得到了作用在动涡旋齿上的轴向、切向及径向气体力随主轴转角的动态变化历程。研究结果表明：新构建的非对称等壁厚型线与传统的等壁厚型线及变壁厚型线相比，其行程容积分别提高了25.99%和7.82%，压缩比分别提高了19.70%和2.04%；而轴向气体力、切向气体力和径向气体力的变化幅度却显著减小，这也证明新构建的非对称等壁厚型线能更好地兼顾传统型线的优点，在容积性能和动力学性能方面更具优势。

关键词: 圆渐开线, 非对称等壁厚型线, 涡旋齿, 变壁厚型线, 气体力