with a nut 55 retaining shaft 52 to plate 46 the nut 55 can be of metal or plastic such as nylon and acts as a bearing against plate 20 to permit the rotation of impeller 45 the shaft 52 extends through a hole 60 in plate 20 which has a bearing 61 therein the shaft 52 has a gear 62 thereon of approximately 3 4 inch diameter which can be retained by a cotter pin 63 which extends through a hole 64 in shaft 52 and holes 65 in gear extension 66 of gear 62 the gear 62 has teeth 67 which are engaged with teeth 68 of a larger gear 70 which is journaled on shaft 71 and is fastened to plate 20 by a screw 72 extending therethrough and into shaft 71 the shaft 71 has an upper bearing portion 73 against which extension 74 of gear 70 bears and the gear 70 is retained on shaft 71 by a c clip 75 in groove 76 of shaft 71 the gear 70 is of approximately three and one half inches in diameter and the gear ratio between gears 62 and 70 is a 6 1 reduction the gears 62 and 70 are preferably of molded synthetic plastic such as nylon a disc 80 of brush assembly 81 is secured to gear 70 by screws 82 which disc is of larger diameter than gear 70 and has a plurality of bristles 83 for scrubbing the pool surface s and propelling the cleaner 10 across the surface as shown in fig5 a the brush assembly 81 is centered on gear 70 referring now to fig5 b the pool cleaner 10 is as described for fig1 5a and 6 but the disc 80 has been.