Effects of Stator Shapes on Hydraulic Performances of an Automotive Torque Converter with a Squashed Torus

Automotive torque converters have recently been designed with a significant flat shape for the purpose of achieving a smaller axial size and reducing weight. Generally, the stator is a very significant component to shorten the axial length of a torque converter. The overall performances of a torque converter, however, mainly depend on the stator geometry. The goal of this study is to investigate effects of the stator with two different shapes suitable for an axially squashed torus. The torque converters were analyzed and experimented in order to confirm the effects of stator shapes on the overall hydraulic performance. Prior to fabricating a prototype sample, complex circulating flow characteristics of the proposed torque converter were investigated by computational analysis using three dimensional CFD code, STAR-CD^®. Experimental analysis was also performed and compared with computational results. As the stator blade shapes changed, the torque capacity factor could be tuned. The modification of stator shape and other design parameters including inlet and outlet angle was used for determining the desirable performance. In addition, the effects of the stator shapes on hydraulic performance variation were investigated. This study provided the main causes of performance variation and useful information for optimum stator blade design.