In comparison to involute internal gear pumps, conjugated straight-line internal gear pumps have the advantages of smaller trapped volume, lower flow ripple, and higher reliability. Conjugated straight-line internal gear pumps were invented by Truninger in 1966; however, because of their unique line type, the main characteristics of these pumps are still not completely understood. Internal gear pairs are the key component of these pumps. To better understand the performance of these pumps, the present research focused on the design of an internal gear pair. A numerical model was developed to demonstrate the design method of the conjugated straight-line internal gear pair. To point out the effective engagement of the gear pair, three fundamental requirements were considered—a conjugated point existed in the tooth profile, no interference occurred during the meshing process, and the overlap coefficient was greater than one. Furthermore, according to the design of the gear pair, flow characteristics and some optimization suggestions for tooth parameters were proposed. The main characteristics of the gear pair were compared with those of an involute gear pair. Finally, a conjugated straight-line internal gear pair machined by the linear cutting method was tested, and the obtained results revealed that the design method was correct.

与渐开线内齿轮泵相比，共轭直线内齿轮泵具有截留容积小、流动脉动小、可靠性高等优点。共轭直线内齿轮泵是特宁格于1966年发明的；然而，由于其独特的管路类型，这些泵的主要特性仍未完全了解。内齿轮副是这些泵的关键部件。为了更好地了解这些泵的性能，目前的研究重点是内齿轮副的设计。开发了一个数值模型来演示共轭直线内齿轮副的设计方法。为了指出齿轮副的有效啮合，考虑了三个基本要求——齿廓中存在共轭点，啮合过程无干扰，重叠系数大于1。此外，根据齿轮副的设计，提出了流动特性和齿参数的优化建议。将齿轮副的主要特性与渐开线齿轮副的主要特性进行了比较。最后，对用直线切削方法加工的共轭直线内齿轮副进行了试验，结果表明设计方法是正确的。