Patent ID: 7785082
Filing Date: 2010-08-31
Classification: F04D

Abstract:
1. A sealless pump comprising: a manifold unit being provided with a suction port and a discharge port, and a motor unit housing a rotating shaft, wherein the rotating shaft is supported by non-contact type bearings which provide support without contacting the rotating shaft, a first impeller being installed to one end of the rotating shaft and a second impeller being installed to other end of the rotating shaft, fluid being pumped is sucked in through the suction port and discharged through the discharge port by utilizing a force being generated by rotation of the first impeller, the non-contact type bearings support the rotating shaft, by utilizing a force being generated by rotation of the second impeller so as to transmit fluid for lubrication to the non-contact type bearings, the first impeller has first blade portions installed in a radial direction with respect to an axis of the first impeller, and outside and inside shrouds installed on the first blade portions, the outside shroud has a first confronting surface which communicates with the discharge port and a second confronting surface which communicates with the suction port, the first confronting surface and the second confronting surface facing the same direction, the fluid at the discharge port applies pressure to the first confronting surface and the fluid at the suction port applies pressure to the second confronting surface, and the area of the first confronting surface is smaller than the area of the second confronting surface.