Expansion rotary engine

Abstract

The present invention introduces two revolutionary concepts (a caterpillar and a squeeze engine) for rotary engines with features highly desirable for space applications, e.g., very high torque, light weight, low power AC or DC input, and smooth stroke over indefinite rotation. Through these unique advantages, the proposed concepts meet an existing demand in the space industry to which, so far, only very high cost and complex solutions have been developed. Although both concepts exploit the same physical phenomenon (the significant 15% volume change related to the paraffin solid-liquid phase change), their similarity stops here. They represent fundamentally different design philosophies and offer different performance characteristics. Preliminary calculations show that the caterpillar engine with no friction-prone slip contacts shall output an approximate 150 lbf--in torque for a 2 inch diameter and 0.5 inch deep cylindrical configuration while consuming approximately 20 W direct current. The corresponding time for one out put revolution might vary between half an hour and an hour depending on technical details. The second engine concept, the squeeze engine, if built with similar overall dimensions and power consumption as the caterpillar engine would produce approximately one ninth the output torque of the caterpillar engine with approximately nine times the speed. The output torque varies as the third power of the scaling of the configurations for both designs.