Rotary pump with bearing wear indicator

The present invention relates to a rotary pump for liquid and more particularly to a rotary pump of the immersed rotor type with a bearing wear indicator. A rotary pump for liquid having a housing, a shaft carrying a motor rotor, a motor stator fixed in the housing and surrounding the rotor to rotate the rotor and shaft about an axis. The shaft is mounted in the pump housing by axially spaced conical bearings, each bearing including a first element fixed on the shaft with a first conical bearing surface concentric with the axis, a coacting second element carried by the housing with a second conical bearing surface concentric with the axis and slidably engaging the first bearing surface and a spring forcing the elements together. This pump includes a wear indicator comprising: a first drive member on the shaft, an imbalance member carried with the second element of a bearing with a second drive member aligned with the first member and movable axially toward the first drive member as the bearing surfaces wear so the first and second drive members engage when the imbalance member moves axially a given distance. A sensor detects vibrations caused by rotation of the imbalance member by the shaft.