JPS6469798A - Fixed bush for sealing pump shaft - Google Patents

Abstract

PURPOSE:To normalize pressure adjustment and prevent the breakage of a throttle valve by setting inner diameters of plural squeezed pieces positioned in the upper course of a shaft sealed part in the space, to which a bleed off pipe is connected, to increase as coming closer to the space and forming them in an end expanding taper shape. CONSTITUTION:On both end sides of a main shaft 2 on which a blade wheel 1 are installed, rotary sleeves 4 fixed on the main shaft 2 are loosely fitted to the squeezed pieces 12 of fixed bushes 5 and shaft sealing parts 15 of a straight type labyrinth packing are formed. A bleed off pipe 7 and a water sealed pipe 8 are arranged in one of the fixed bushes 5 and one of holders 6 and they are connected respectively to first and second pipe connecting space 13, 14 formed on the shaft sealed part 15. In this case, the inner diameters of plural squeezed pieces 12 formed on one of the fixed bushes 5 positioned to the connecting part located on the upper course of the shaft sealed part 15 in the first space 13 are set to increase as coming closer to the first space 13. In other words, they are formed in an end expanding taper space like phid0<phid1<phid2<phid3<phid4.