Improving the Efficiency of Processing Complex Automotive Surfaces Using Hand-held Machines with Cycloidal Motion

This paper addresses the pressing practical problem of improving the efficiency of hand-held machines, whose performance in traditional designs has reached its technological limit. It substantiates the high potential of using cycloidal (planetary-rotary) motion for actuators, which opens up new possibilities for processing complex contours, especially when repairing large automotive surfaces.Based on the analysis of satellite curves, the theoretical foundations for the design of such machines have been developed. Hypotrochoidal schemes with an internal envelope are recommended as the simplest and most effective solution, where the scheme with a three-vertex working body (z = 3) is recognized as optimal. To implement the movement, James' planetary mechanism is proposed, which has high efficiency (0.99) and a rational transmission ratio (i = 3 … 8). Mathematical models have been developed that describe the geometry of the working body and the conditions for obtaining straight sections on its trajectory.Based on these studies, an experimental model of a hand-held polishing and grinding machine has been created. The design with a triangular-shaped working tool allows for high-quality processing of angular and hard-to-reach areas. The introduction of such machines into repair and construction production reduces labor costs by 20 … 30%, significantly increasing productivity and the quality of surface finishing.