impeller 58 is attached to the end of rotor shaft 40 by suitable means and a cap element 60 fastens the impeller 58 to the rotor shaft an expansion plug 62 is provided in motor end frame 18 a suction plate 64 defines suction chamber 66 of pump assembly 10 the above described unit bearing assembly embodiments provide a unique bearing construction between a rotor shaft or rotor core and the motor housing which encompasses the rotor core and shaft the unit bearing tower 24 provides a bearing element which by means of counterbore 42 extends into the rotor core and embraces or surrounds the rotor shaft at a point prior to the emergence of the rotor shaft from the rotor core this construction allows the motor and housing unit to be relatively more compact resulting in a shorter motor package additionally the unit bearing tower 24 in the embodiment of fig1 provides an elongated bearing surface which embraces rotor shaft 40 over a relatively longer length of the shaft providing added support for the shaft and decreasing the shaft 39 s tendency and ability to wobble also since the disclosed construction enables the use of a shorter rotor shaft 40 there is an additional reduction in the tendency of the shaft to wobble alignment of the shorter shaft 40 is also easier using the disclosed construction the counterbore 42 also provides a decreased moment arm acting on the bearing system for rotor shaft 40 this reduces the moments acting along the length of shaft 40 and allows use of a smaller diameter less rigid rotor shaft 40 providing added cost savings in manufacturing units such as pump assembly 10 in addition unit bearing tower 24.