Patent ID: 6318641
Filing Date: 2001-11-20
Classification: F02M,F16K,Y10T

Abstract:
A shape memory alloy fuel injector having forced convective heat transfer and having a small package integral design, comprising:an actuator assembly including an actuator wafer containing a valve and at least one shape memory alloy element in contact with the valve, the shape memory alloy element further having a characteristic phase change transition temperature wherein the shape memory alloy element and the valve have a first position at a temperature below the transition temperature and a second position at a temperature above the transition temperature, and wherein the width and length of the actuator assembly are substantially dictated by the width and length of the shape memory alloy element; anda metering orifice plate comprising an orifice wafer bonded to said actuator wafer and includinga flow metering orifice which is blocked by the valve at either the first position or second position of the shape memory alloy element and the valve, thereby providing a metered flow of fluid through the fuel injector;at least one inlet flow path and at least one outlet flow path, wherein the at least one inlet flow path and the at least one outlet flow path direct a flow of fluid independent from the metered flow of fluid across the shape memory alloy element, thereby providing a thermal boundary layer between the shape memory alloy element and the bulk flow of fluid that results in an enhanced convective heat transfer rate from the shape memory alloy element.