LuK GmbH & Co. KG · Germany

The various elements of the torque converter: fluid circuit, lock-up clutch and damper, have undergone tremendous optimization efforts over the last 100 years. Today, a torque converter with a length of 80mm can be used in an application where 125mm was once required. However, this effort has not had much influence on the stator and one-way clutch. It’s axial length is about the same and it now represents a roadblock to further axial length reduction. To break open this roadblock, LuK has developed two new paradigms.

First, the blade length has been reduced half. Since, the blades play the critical role of turning the fluid in the fluid circuit, thereby creating torque multiplication, their function must be maintained. This is accomplished by doubling the number of blades. The blades now carry only half the torque per blade and so their thickness can be reduced. This results in an increase in flow-area of the stator, especially near the coupling point. This improves torque capacity at the coupling point, improving fuel economy. These blades can be easily made from sheet metal as two stampings. Each stamping carries half of the blades and they are assembled around the one-way clutch.

LuK’s second paradigm shift is in the one-way clutch concept. Since the blade plates present adequate sheet metal, a ratchet one-way clutch can be created from only a few additional stamped components. The high torque density of this type of clutch allows a significant length reduction, complementing the new blade design.

Together, these new paradigms create the Super Slim Stator assembly. In the first application, an axial length savings of 60% or 18mm was achieved. With an overall converter length of only 80mm, this is a significant achievement. This space can be used for a variety of purposes depending on the application. If cost is the key driver, a more efficient piston plate can be created and the damper connections can be more easily made. This allows a thinner piston plate and saves welding operations. If axial length is the key issue, the new space can be used for its reduction. If space is needed for a high capacity damper or a twin-plate clutch, it is available due to the Super Slim Stator from LuK!