Vortex expander with variable-cross-section vortex teeth

The invention discloses a vortex expander with variable-cross-section vortex teeth. According to the vortex expander, a forming line of a static vortex tooth (101) is composed of four sections of smoothly connected curves, sequentially namely a first trigonometric function involute AE, a first arc AB, a second arc BC and a fourth trigonometric function involute CD; and a forming line of a movablevortex tooth (201) is composed of four smoothly connected curves, sequentially namely a second trigonometric function involute FJ, a third arc FG, a fourth arc GH and a third trigonometric function involute HI. In the working process, the static vortex teeth (101) and the movable vortex tooth can be completely and correctly meshed. According to the vortex expander with the variable-cross-section vortex teeth, the lines of the vortex teeth are simple in composition, the interior volume specific ratio is large, the number of turns is small, and the length of the leakage line is short; and meanwhile, the tooth thickness