Development of An Adjusting Mechanism for An Air Flap Based On R-Phase Transformation

The R-phase transformation has a particular relevance for actuators, because it has special properties. The main advantage of the R-phase transformation is the small temperature hysteresis. Thereby the R-phase actuators are usable for applications that require a fast reaction to temperature change. The activation of the actuators is caused by a variation of the ambient temperature and therefore spares an external energy supply. These actuators are space saving and noiseless. R-phase actuators may be especially useful in heating engineering and air-conditioning.

The aim of this paper is to demonstrate the applicability of the R-Phase transformation in air-conditioning. Therefore, an application was chosen that meets the profile of requirements for R-phase actuators. This application is an adjusting mechanism for a flap. This flap controls the rate of fresh and circulating air in a vehicle. So far the application was solved manual or with an electromechanical actuator.

This paper first of all presents actual applied variants of adjusting mechanisms with their characteristics. After that the product development process of the adjusting mechanisms, based on the R-phase transformation, will be described. This process includes the important steps, such as the requirements definition, the development of concepts and the design of the R-Phase actuator and its return element. Additionally, this paper contains the results of the experiments for the validation of the R-phase actuator. Finally the prototype of the flap adjusting mechanism will be presented and its functionality will be proved.