Abstract: A pump comprising a housing, a diaphragm mounted in the housing, a pumping member or members, and a drive, preferably a wobble plate drive, for driving the pumping member or members on intake and discharge strokes. The wobble plate is preferably mounted on a ball bearing and includes a snap retainer assembly to retain the bearing in place without force fitting. The wobble plate preferably defines one or more open ended chambers in which the pumping member or members are placed. The annular zone or zones of the diaphragm which flex when driven by the wobble plate drive to provide the pumping action are configured to increase efficiency and/or to reduce wear.