Abstract: A spool-shaped metallic heat barrier is inserted between the motor housing and the pump housing of a motor-pump assembly which conveys fluids at elevated temperatures. The flanges of the heat barrier abut against and are connected to the respective housings by means of bolts, and are rigidly secured to each other by several annuli of discrete heat dissipating ribs which are adjacent to the peripheries of the flanges. That flange which is adjacent to the motor housing can be formed with a peripheral groove the radially outermost portion of which receives a ring-shaped closure so that the inner portion of the groove forms an annular channel for reception of a stagnant or circulating liquid coolant.

Abstract: A glandless centrifugal pump and wet electric motor unit for use in fossil-fired power plants has a cover which is sealingly connected with one end of the main portion of the motor housing and contains one or more cyclone separators for solid impurities. Liquid to be relieved of solid impurities is fed into the cover by way of a tangential inlet and such liquid passes through a coarse-mesh sieve which intercepts large solid impurities before the thus filtered liquid reaches the cyclone separator or separators. The separator or separators admit cleaned liquid into a channel provided which is provided therefor in the housing of the motor. The smaller solid impurities accumulate in a chamber which can be cleaned by way of a sealable opening while the cover remains attached to the main portion of the housing.

Abstract: A pump assembly for circulation of liquid coolant in boiling water reactors has a thin-walled spherical pump body for an impeller which rotates about a vertical axis and an electric motor which drives the impeller and has an upright housing with a heat barrier at its upper end. The heat barrier has a thin-walled neck portion which surrounds the impeller shaft below an opening in the lower part of the pump body and a ring-shaped surface which is biased against a complementary surface of the pump body around the opening by several heat-expansible bolts which separably couple the housing to the pump body. The heat barrier has an annular air space surrounding the neck portion and being surrounded by an annulus of cooling ribs, an upper flange which abuts against the pump body and has one or more compartments for a circulating coolant, and a lower flange with one or more compartments for a circulating coolant.

Abstract: A glandless pump and wet motor unit for circulating water in a boiler has an axially movable shaft which is rotatable in a liquid-filled housing of the motor and carries a disk disposed between electromagnets which are energizable to produce an electromagnetic field serving to maintain the shaft through magnetic bearings in a selected axial position when the electromagnets are energized. At least one mechanical auxiliary thrust bearing is provided in the housing and becomes effective in response to deenergization of the electromagnets. The auxiliary bearing may be a Kingsbury bearing which is spaced apart from the electromagnetic thrust bearing, or the auxiliary bearing may include the disk which cooperates with adjacent surfaces of the electromagnets or with adjacent surfaces of the housing when the shaft is subjected to axial stresses while the electromagnets are deenergized.