Thrust bearing base for an electrical submersible well pump having an integrated heat exchanger

A submersible well pump assembly, comprising:

• a pump driven by an electrical motor;
• a thrust bearing module between the pump and the motor, comprising:
• a housing having a longitudinal axis;
• a base secured to and extending downward from a lower portion of the housing, the base having an axial bore in fluid communication with lubricant in the motor, the base having a motor end connector below the housing for connecting the thrust bearing module to the motor;
• a shaft extending through the bore and into the housing;
• a thrust bearing assembly for absorbing thrust on the shaft, the thrust bearing assembly being located in a chamber in the housing, the chamber having a lower end at an upper end of the base;
• a lubricant pump mounted in the bore and coupled to the shaft for rotation therewith for pumping lubricant upward in an annular clearance between the shaft and a side wall of the bore into the chamber;
• a passage having an inlet port in the chamber and an outlet port within the bore for returning lubricant pumped by the lubricant pump from the chamber, the passage extending internally through the base between the bore and an outer surface of the base and having a plurality of turns encircling the bore;
• wherein
• the lower portion of the housing has internal threads, and an upper portion of the base has external threads that engage the internal threads;
• the base has a neck extending downward from the upper portion of the base, the neck having a smaller outer diameter than the upper portion of the base;
• a plurality of the turns of the passage are located in the upper portion of the base;
• and
• at least one of the turns of the passage is located in the neck.

A submersible well pump assembly, comprising:

• a pump driven by an electrical motor;
• a thrust bearing module between the pump and the motor, comprising:
• a housing having a longitudinal axis and a lower end portion with internal threads;
• a thrust bearing chamber in the housing;
• a base defining a lower end of the thrust bearing chamber, the base having an upper portion with external threads secured to the internal threads of the housing, the base having a neck portion extending downward from the upper portion, the neck portion having a smaller diameter than the upper portion of the base and extending downward from the lower portion of the housing, the base having an axial bore in fluid communication with lubricant in the motor, the base having a motor end connector on the neck portion for connecting the thrust bearing module to the motor;
• a shaft extending through the bore and into the housing;
• a thrust bearing assembly for absorbing thrust on the shaft, the thrust bearing assembly being located in the thrust bearing chamber;
• a lubricant pump mounted in the bore and coupled to the shaft for rotation therewith for pumping lubricant upward in an annular clearance between the shaft and a side wall of the bore into the thrust bearing chamber;
• a passage having an inlet port in the chamber and an outlet port within the bore for returning lubricant from the thrust bearing chamber to the bore, the passage extending internally through the base and having a plurality of turns encircling the bore in the upper portion of the base and at least one turn encircling the bore in the neck portion of the base;
• and wherein
• the turns of the passage define a conic helical configuration, decreasing in diameter in a downward direction.