Scroll compressor having improved orbital drive mechanism

Abstract

A scroll compressor includes an orbital drive mechanism for orbiting an orbiting scroll relative to a stationary scroll. The orbiting scroll is formed with a generally cylindrical boss extending in a direction away from the stationary scroll. The orbital drive mechanism includes a main shaft rotatably supported by a compressor housing, an eccentric shaft extending from one end face of the main shaft and having a longitudinal axis parallel to, but offset laterally from a longitudinal axis of the main shaft, and an eccentric bush having a socket inserted rotatably into the cylindrical boss. The eccentric shaft, engaged in the socket, has first and second rounded side faces opposite to each other both having a common center of curvature, while the socket has first and second inner wall portions opposite to each other, each of which has a center of curvature substantially aligned with the common center of curvature of the first and second rounded side faces of the eccentric shaft. Third and fourth side faces of the eccentric shaft extending between associated ends of the first and second rounded side faces confront third and fourth inner wall portions of the socket and are spaced inwardly therefrom so that the eccentric bush can swing relative to the eccentric shaft about the common center of curvature of the first and second rounded side faces of the eccentric shaft, thus varying the orbiting radius.