摘要:Based on the obtained mathematical models of straight-line gears, this article focuses on the investigation of fluid delivery and trapped volume performances of Truninger gear pumps. Considering the nonlinear relationship in mesh movement of straight-line gears, it is hard to derive explicitly solvable formulas of displacement and trapped volume with traditional methods. A discretization approach is proposed to obtain the numerical solutions. Then, the performances of fluid delivery and trapped volume are discussed. The results show that the trapped volume of Truninger gear pumps only has an expansion process, which avoids the pressure rise caused by the compression of trapped volume and has no contribution to the fluid delivery of pumps. To design Truninger gear pumps with a good delivery capacity, it is practical to choose a small tooth thickness, a large tooth number of the pinion, and a large profile angle with the proper choice of addendum coefficient and dedendum coefficient. Taking the example in this article for illustration, it may choose a tooth thickness of 3 mm, a tooth number of the pinion of 15, a tooth number of the internal gear of 18, a profile angle of 24°, an addendum coefficient of 0.66, and a dedendum coefficient of 0.9.