Abstract: A rotary vibrator having a housing, a rotating shaft, and one or more eccentric weights having a hub portion mounted on the shaft and an eccentric portion extending outwardly from the hub generally perpendicular to the rotational axis. Each eccentric portion is defined by leading and trailing edges extending generally radially from the hub and connected to an outer periphery. Air inlet and outlet passages are arranged longitudinally in the housing at each end thereof for the purpose of admitting and circulating air in and around the bearings of the vibrator. The faces of the leading edges of the eccentric weights are beveled toward the outlet passages in a manner so that upon rotation of the vibrator, the leading edges will act like a propeller to draw air in through the inlet passages, circulate it through the housing and push it out through the outlet passages, thereby to ventilate and cool the vibrator bearings.