Downhole motor driven reciprocating well pump

A submersible well pump assembly, comprising:

• a pump housing having a longitudinal axis, a well fluid inlet and a well fluid discharge;
• a pump barrel located within the pump housing, defining an annular passage between the barrel and the pump housing, the annular passage being in fluid communication with the well fluid discharge, the barrel having an intake end in fluid communication with the well fluid inlet;
• a plunger reciprocally carried in the barrel, the plunger having a piston shoulder facing opposite the intake end of the barrel, and the plunger being movable between a power stroke and an intake stroke;
• a barrel outlet port that communicates well fluid from the barrel on a power end of the plunger into the annular passage;
• a plunger passage extending axially within the plunger, the plunger passage having an intake end and discharge end;
• a plunger port communicating the discharge end of the plunger passage with the barrel and the barrel outlet port to flow well fluid from the plunger passage out the barrel outlet port;
• a traveling valve carried by the plunger at the intake end of the plunger passage, the traveling valve closing the intake end of the plunger passage during the power stroke, thereby with the piston shoulder, pushing well fluid out the barrel outlet port into the annular passage and from the annular passage out the well fluid discharge;
• the traveling valve opening the plunger passage during the intake stroke, thereby allowing well fluid to flow into the plunger passage from the intake end of the barrel;
• and
• a motor mounted to an end of the pump housing opposite the well fluid discharge and operatively coupled to the plunger by a connecting rod, the motor reciprocating the rod to cause the plunger to move between the power stroke and the intake stroke, the connecting rod being in tension during the power stroke.

A submersible well pump assembly, comprising:

• a pump housing having a longitudinal axis, a well fluid inlet and a well fluid outlet located coaxially with the axis above the well fluid inlet;
• a pump barrel within the pump housing, defining an annular passage between the barrel and the pump housing;
• a plunger reciprocally carried in the barrel and movable between a down stroke and an up stroke, the plunger having a plunger cavity therein;
• a well fluid inlet in the housing defining a well fluid inlet path that admits well fluid into the barrel above the plunger;
• a traveling valve on an upper end of the plunger cavity that moves with the plunger, the traveling valve having an open position that admits well fluid from the barrel above the plunger into the plunger cavity during the up stroke, and the traveling valve having a closed position during the down stroke;
• a plunger port in a lower end of the plunger cavity in fluid communication with the barrel below the plunger for flowing well fluid in the plunger cavity into the barrel below the plunger;
• a barrel outlet port that defines a well fluid outlet path communicating well fluid from the barrel below the plunger with the annular passage;
• a standing valve in the well fluid outlet above the well fluid inlet;
• a discharge port leading from the annular passage to a lower side of the standing valve, the standing valve having a closed position during the up stroke and an open position during the down stroke;
• and
• a motor mounted to a lower end of the pump housing and operatively coupled to a lower end of the plunger by a connecting rod, the motor reciprocating the rod to cause the plunger to move between the up stroke and the down stroke.